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Contract No. DE-AC36-08GO28308

Fuel Cell Power Model Version 2: 

Startup Guide, System Designs, 

and Case Studies

Modeling Electricity, Heat, and 

Hydrogen Generation from Fuel CellBased Distributed Energy Systems

D. Steward, M. Penev, G. Saur, and W. Becker

National Renewable Energy Laboratory

J. Zuboy

Consultant

Technical Report

NREL/TP- 5600-57457

June 2013
NREL is a national laboratory of the U.S. Department of Energy

Office of Energy Efficiency & Renewable Energy

Operated by the Alliance for Sustainable Energy, LLC

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications.

Contract No. DE-AC36-08GO28308

National Renewable Energy Laboratory

15013 Denver West Parkway

Golden, CO 80401

303-275-3000 • www.nrel.gov

Fuel Cell Power Model Version 2: 

Startup Guide, System Designs, 

and Case Studies

Modeling Electricity, Heat, and 

Hydrogen Generation from Fuel CellBased Distributed Energy Systems

D. Steward, M. Penev, G. Saur, and W. Becker

National Renewable Energy Laboratory

J. Zuboy

Consultant

Prepared under Task No. HT12.2015

Technical Report

NREL/TP-5600-57457

June 2013
NOTICE

This report was prepared as an account of work sponsored by an agency of the United States government. 

Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, 

express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of 

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owned rights. Reference herein to any specific commercial product, process, or service by trade name, 

trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, 

or favoring by the United States government or any agency thereof. The views and opinions of authors 

expressed herein do not necessarily state or reflect those of the United States government or any agency thereof.

This report is available at no cost from the National Renewable Energy

Laboratory (NREL) at www.nrel.gov/publications.

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Cover Photos: (left to right) photo by Pat Corkery, NREL 16416, photo from SunEdison, NREL 17423, photo by Pat Corkery, NREL 

16560, photo by Dennis Schroeder, NREL 17613, photo by Dean Armstrong, NREL 17436, photo by Pat Corkery, NREL 17721.

 Printed on paper containing at least 50% wastepaper, including 10% post consumer waste. 
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Table of Contents

1 Startup Guide........................................................................................................................................ 1

1.1 Introduction...................................................................................................................................... 1

1.2 Getting Around ................................................................................................................................ 4

1.3 Tips & Troubleshooting................................................................................................................... 5

1.4 Configuring Your Simulated Distributed Energy System ............................................................... 5

1.4.1 Project Configuration........................................................................................................ 6

1.4.2 Building Characteristics.................................................................................................... 9

1.4.3 Equipment Configuration................................................................................................ 11

1.4.4 Purchased Electricity Price ............................................................................................. 12

1.4.5 Capital and Operating Costs ........................................................................................... 13

1.4.6 Energy Analysis.............................................................................................................. 16

1.4.7 Financial Assumptions.................................................................................................... 17

1.5 Calculating Financial, Energy, and Emissions Results.................................................................. 18

1.6 Technical Support.......................................................................................................................... 21

2 Designs of the FCPower Model Fuel Cell Systems......................................................................... 22

2.1 Introduction.................................................................................................................................... 22

2.2 Molten Carbonate Fuel Cell System.............................................................................................. 22

2.2.1 Molten Carbonate Fuel Cell Operation........................................................................... 23

2.2.2 ASPEN Model of MCFC-CHP System .......................................................................... 24

2.2.3 ASPEN Model of MCFC-CHHP System ....................................................................... 25

2.2.4 Modeling MCFC Systems with the FCPower Model ..................................................... 26

2.2.5 Correlation of MCFC ASPEN Model and FCPower Model........................................... 28

2.3 Phosphoric Acid Fuel Cell System ................................................................................................ 30

2.3.1 Phosphoric Acid Fuel Cell Operation ............................................................................. 30

2.3.2 ASPEN Model of PAFC-CHP System ........................................................................... 31

2.3.3 ASPEN Model of PAFC-CHHP System......................................................................... 33

2.3.4 Modeling PAFC Systems with the FCPower Model ...................................................... 34

2.3.5 Correlation of PAFC ASPEN Model and FCPower Model............................................ 36

2.4 Solid Oxide Fuel Cell System........................................................................................................ 38

2.4.1 Solid Oxide Fuel Cell Operation..................................................................................... 38

2.4.2 ASPEN Model of SOFC-CHP System ........................................................................... 39

2.4.3 ASPEN Model of SOFC-CHHP System......................................................................... 41

2.4.4 Modeling SOFC Systems with the FCPower Model ...................................................... 42

2.4.5 Correlation of SOFC ASPEN Model and FCPower Model............................................ 44

2.5 FCPower Model Energy Balance................................................................................................... 45

2.6 ASPEN System Process Flow Diagrams and Energy/Material Stream Tables ............................. 49

3 FCPower Model Case Studies........................................................................................................... 79

3.1 Molten Carbonate Fuel Cell Case Study Description .................................................................... 79

3.1.1 Financial Inputs............................................................................................................... 79

3.1.2 Load Profile and Fuel Cell Specification........................................................................ 81

3.1.3 Utilities............................................................................................................................ 81

3.2 Molten Carbonate Fuel Cell Case Study Results........................................................................... 82

3.2.1 Baseline System.............................................................................................................. 82

3.2.2 CHHP System Energy Supply ........................................................................................ 82

3.2.3 CHHP System Capital Costs and Credits........................................................................ 83

3.2.4 MCFC CHHP System Cash Flow................................................................................... 84

3.2.5 Cost of Hydrogen and Total Annualized Costs............................................................... 85

3.2.6 Sensitivity Analysis......................................................................................................... 85
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3.3 Phosphoric Acid Fuel Cell Case Study Description ...................................................................... 86

3.3.1 Financial Inputs............................................................................................................... 87

3.3.2 Load Profile and Fuel Cell Specification........................................................................ 89

3.3.3 Utilities............................................................................................................................ 89

3.4 Phosphoric Acid Fuel Cell Case Study Results............................................................................. 90

3.4.1 Baseline System.............................................................................................................. 90

3.4.2 CHHP System Energy Supply ........................................................................................ 90

3.4.3 CHHP System Capital Costs and Credits........................................................................ 90

3.4.4 PAFC CHHP System Cash Flow.................................................................................... 91

3.4.5 Cost of Hydrogen and Total Annualized Costs............................................................... 92

3.4.6 Sensitivity Analysis......................................................................................................... 93

3.5 Solid Oxide Fuel Cell Case Study Description.............................................................................. 93

3.5.1 Financial Inputs............................................................................................................... 94

3.5.2 Load Profile and Fuel Cell Specification........................................................................ 95

3.5.3 Utilities............................................................................................................................ 95

3.6 Solid Oxide Fuel Cell Case Study Results..................................................................................... 95

3.6.1 Baseline System.............................................................................................................. 95

3.6.2 CHHP System Energy Supply ........................................................................................ 96

3.6.3 CHHP System Capital Costs and Credits........................................................................ 96

3.6.4 SOFC CHHP System Cash Flow.................................................................................... 97

3.6.5 Cost of Hydrogen and Total Annualized Costs............................................................... 98

3.6.6 Sensitivity Analysis......................................................................................................... 98

4 References ........................................................................................................................................ 100
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1 Startup Guide

1.1 Introduction

The Fuel Cell Power (FCPower) Model is a Microsoft Excel workbook that analyzes the 

technical and economic aspects of high-temperature fuel cell–based distributed energy systems 

with the aim of providing consistent, transparent, comparable results. This type of energy system 

would provide onsite-generated heat and electricity to large end users such as hospitals and 

office complexes. The hydrogen produced could be used for fueling vehicles or stored for later 

conversion to electricity.

Figure 1. Schematic of a fuel cell-based distributed energy system

In the FCPower Model, users select which technologies are used in the system (see Figure 1)—

such as hydrogen fuel cells, photovoltaic (PV) panels, and electrolyzers—and define each 

technology's cost and performance parameters. Users also select fuel costs and demand priority 

(i.e., whether the system follows electricity or heat demand) and can accept default FCPower 

Model financial parameters or enter custom parameters. Hourly electricity, heat, and hydrogen 

demand profiles and renewable energy supply profiles can be entered or selected from databases.

The model uses the inputs, default values, calculations, and a standard discounted cash flow rate 

of return methodology to determine the cost of delivered energy, with reference to a specified 

after-tax internal rate of return. It also determines the amount and type of energy input and 

output and the associated greenhouse gas emissions. 

Electricity

Grid

Water

Fuel

Sun

Hydrogen

Fuel burner

heat sink

FC SYSTEM + PSA

PV

electrolyzer

H2-FC

H2-storage

Heat

Wind Turbines
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In the model, the fuel cell system is integrated with the building heat and electrical demand, and 

hydrogen is assumed to be produced for onsite use (e.g., in forklifts or fuel cell electric vehicles) 

or delivery for use offsite (see Figure 2). Arrows that cross the analysis boundary are explicitly 

accounted for in the discounted cash flow analysis. Internal arrows represent the avoided costs 

(revenue) for supplying electricity, heat, and hydrogen via the fuel cell system. The model solves 

for the total revenue derived for these energy services that is equal to the annualized profited cost 

for the fuel cell installation. 

Initially, the model solves for a total cost of energy in dollars per kWh and does not allocate 

costs among the three types of energy (electricity, heat, and hydrogen). Then there are two 

options: allocate costs based on user input or resort to a default allocation. If the user sets the 

costs for two of the energy types, then these values are subtracted from the total energy cost to 

calculate the cost of the third energy type. In the default case, electricity supplied by the fuel cell 

is assigned the same value as electricity purchased from the grid, and heat from the fuel cell is 

assigned the same value as would have been paid for heating from a natural gas heating system.

Hydrogen is then the third (free) variable, and its value is calculated as the remaining cost. If the 

user selects heat or electricity as the free variable, the hydrogen value is set at the profited cost of 

producing hydrogen from a standalone steam methane reforming (SMR) system. 

Figure 2. FCPower Model CHHP analysis boundary

The output of the model is compared with a baseline system in which electricity is supplied by 

the electric grid, heat is supplied by a natural gas heating system, and hydrogen is supplied by a 

standalone SMR system (see Figure 3). 
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Figure 3. Baseline system analysis boundary

The FCPower Model comes in three different versions (i.e., three different Excel workbooks): 

one version based on a molten carbonate fuel cell (MCFC) system, one based on a phosphoric 

acid fuel cell (PAFC) system, and one based on a solid oxide fuel cell (SOFC) system. One of 

the major differences between the systems is that the PAFC system (see Figure 4) has a separate 

reformer; hydrogen is produced by diverting some of the reformed syngas to a hydrogen 

separator, allowing the production of additional hydrogen via oversizing the reformer relative to 

the fuel cell. In contrast, the MCFC and SOFC systems (see Figure 5) have internal reformers, 

and heat from electricity-production efficiency losses is used to produce hydrogen. A 

consequence of the different technologies is that the model can be set to follow heat or electricity 

demand for the PAFC system, whereas the model can only follow electricity demand for the 

MCFC and SOFC systems. This function is discussed later in this guide. 

Figure 4. Schematic of a PAFC system

Syngas

Electricity

Water

Fuel

Heat

Excess Syngas

REFORMER

Hydrogen

FUEL CELL

Recycle H2-Separation Storage & 

Dispensing
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Figure 5. Schematic of MCFC and SOFC systems 

The first section of this guide helps users get started with the FCPower Model. Note that screen 

captures and values shown in this guide are for illustration only and will not necessarily match 

what appears in the version of the model or case study you are using. More detailed instructional 

materials and model documentation are being developed and will be posted on the following 

website as they become publicly available: www.hydrogen.energy.gov/fc_power_analysis.html. 

Also visit this website to download the most updated version of the model. Section 2 of this 

guide describes the technical characteristics of the fuel cell systems on which the FCPower 

Model is based, and Section 3 describes FCPower Model case studies.

1.2 Getting Around

The FCPower Model workbook is organized into a series of worksheets, which are linked by tabs 

as shown in Figure 6. Some of the worksheets are used for all analyses and are always visible, 

whereas others become visible or invisible based on whether or not they are being used for a 

specific analysis.

Worksheets with green tabs are for user input and information. Worksheets with blue tabs are for 

model results. Worksheets with yellow tabs are for data and properties such as feedstock prices 

and heating values. Worksheets with gray tabs show standard calculations and variables and 

should not be modified directly by users. Darker-shaded tabs indicate worksheets accessed 

frequently by users. Lighter-shaded tabs indicate infrequently accessed or calculation 

worksheets.

Figure 6. FCPower Model worksheet tabs

Fuel Cell Fuel Electricity

Internal 

Reforming

Hydrogen

Heat

MCFC/SOFC
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1.3 Tips & Troubleshooting

• Before you start modifying the model, save the file under a new name. This will make it 

simple to go back to the unmodified model later if necessary. 

• If the file you are working with accumulates numerous errors, you delete information that 

you later find you need, etc., it might be easier to discard the file and start afresh with the 

original version of the model. If you have not kept an original version, download the 

model again from the following website: 

www.hydrogen.energy.gov/fc_power_analysis.html. 

• Throughout the model, orange cells are meant to accept static user-input values or userdefined equations, and blue cells are calculated automatically by the model. Use care if 

you overwrite the blue calculation cells with static values or your own equations; once 

overwritten, the original equation information is permanently deleted. Green cells are for 

notes that do not participate in calculations. 

• Do not type values into cells with drop-down menus. Select only from values in the 

menu. 

• If it is not obvious how to close or move on past a pop-up window, you can close it by 

clicking the in the upper right corner. 

• Mouse over small red triangles for additional detail as shown in Figure 7. 

Figure 7. Example of pop-up notes

• The model works best (i.e., has the least likelihood of errors) when you fill out the 

Project Setup worksheet and all linked worksheets as completely as possible, starting 

with the top and working down. After filling out all relevant worksheets completely, run 

the model using the button in the Project Setup worksheet. 

1.4 Configuring Your Simulated Distributed Energy System

When you open the model, you will start in the Description worksheet, which contains basic 

information about the model and the case study you are working on. The FCPower Model’s 

default case study is a large hotel in Los Angeles.
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From the Description worksheet, clicking the Project Setup button sends you to the Project 

Setup worksheet. The Project Setup worksheet will be your “home base” for configuring your 

simulated distributed energy system. You will complete the worksheet from top to bottom—

linking to other worksheets to enter information as necessary—and returning to the Project Setup

worksheet to run the hourly energy profile and calculate costs. The following information 

describes how to complete each section of the Project Setup worksheet and related worksheets. 

1.4.1 Project Configuration

The Project Configuration section is the first part of the Project Setup worksheet (see Figure 8). 

In this section, the first choice you make is the type of entity that will be using the distributed 

energy system: commercial/regulated utility or government/tax exempt. This choice determines 

some of the model’s financial inputs and calculations, related to taxation and depreciation. 

Figure 8. Project Setup worksheet 

Next, you choose the building system configuration from among three choices: combined heat 

and power (CHP); combined heat, hydrogen, and power (CHHP); and custom. The model will 

adjust automatically to collect the relevant information based on the type of system you choose. 

The CHP system is the simplest of the three systems. The fuel cell system provides electricity 

and heat to meet building demands, buying supplemental grid electricity and natural gas heating 

as necessary and selling electricity to the grid when the fuel cell’s output is greater than the 

building’s demand. No hydrogen is produced with this system. The CHHP system performs the 

same functions as the CHP system and adds the ability to produce hydrogen. The custom system 

allows you to add components to the CHHP system. Choices include solar and wind electricity 

production, electrolytic hydrogen production, hydrogen storage, hydrogen fuel cells, and a 

natural gas burner. If you select the custom system, you will be sent to the PFD worksheet (see 

Figure 9), where you will select the components of your system and then click the Done button 

to return to the Project Setup worksheet.
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Figure 9. PFD worksheet (for the custom configuration) 

After you select the building system configuration (see Figure 10 for schematics), you enter or 

accept the default values for project timeline information, including reference year for costs, 

anticipated start-up year, length of construction period, equipment start-up duration, and total 

equipment life. Then you proceed to the Building Characteristics section. 

Selected technology 

(peak burner)

Technology not selected 

(electrolyzer)

Done button (return 

to Project Setup 

worksheet)
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Figure 10. Schematics of building system configuration choices

Combined Heat and Power

Combined Heat, Hydrogen and Power

Custom
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1.4.2 Building Characteristics

The Building Characteristics section of the Project Setup worksheet prompts you to import 

building electricity and heat load profiles and a hydrogen demand profile for your system. The 

FCPower Model calculates the types and amounts of energy used and produced primarily based 

on electricity and heat demand profiles. The AC Demand (electricity) and Heat Demand (heat) 

worksheets contain energy demand values for each of the 8,760 hours in a year. The model's 

standard case study location for the purposes of the demand profiles is a large hotel in Los 

Angeles (see Figure 11). If the model is set to follow the electrical load, the system will make 

meeting electricity demand its top priority. If the model is set to follow the heat load (only 

available in the PAFC system model), the system will make meeting heat demand its top priority.

The model also uses a hydrogen demand profile, contained in the H2 Demand worksheet. 

However, the model cannot be set to follow a hydrogen load. Hydrogen demand is only 

applicable to CHHP and custom system configurations, not to the CHP configuration. 

You can accept the default electricity, heat, and hydrogen demand profiles or modify them by 

modifying the values in their respective worksheets. However, because there are 8,760 data 

points, this approach is usually impractical. Instead, you can import profiles (except for hydrogen 

profiles).

Click the Go To button adjacent to Enter or Import Building Load Profiles. A popup window 

asks if you want to import a new building profile or use the existing/default profile. Click Yes to 

import a new profile. A browser window opens allowing you to locate and select an 

appropriately formatted electricity/heat demand file (which can be downloaded at 

www.hydrogen.energy.gov/fc_power_analysis.html). Follow the prompts to select the desired 

file. The electricity and heat profiles from the file you selected automatically replace the profiles 

in the AC Demand and Heat Demand worksheets. Enter or accept the default year for the 

demand profile on the AC Demand worksheet (see Figure 12); this value is used to determine the 

day of the week for January 1 of that year.

If you chose a custom building configuration and selected PV and/or wind as part of your 

system, after you select an electricity/heat profile you will be prompted to select solar and wind 

profiles (which can be downloaded at www.hydrogen.energy.gov/fc_power_analysis.html). If 

the solar/wind profile file is stored in the same folder as the electricity/heat profile file that you 

imported, the model will automatically import the solar/wind file from that location. If the 

solar/wind file is in another location, you will have the opportunity to navigate to the file and 

select it (if no solar/wind profile is available, it is best to deselect PV and/or wind turbines in the 

PFD worksheet). If PV is part of your system, you will be asked to input the latitude of your 

building’s location during this process. The availability profiles will be entered into the Solar 

Availability and Wind Availability worksheets. Click the Done button to return to the Project 

Setup worksheet. 

Next, click the Go To button adjacent to Enter Hydrogen Demand Profile. This sends you to the 

H2 Demand worksheet, where you can specify average daily hydrogen demand and demandsurge characteristics. Click the Done button to return to the Project Setup worksheet. 
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Figure 11. Graphs of default electricity (top) and heat (bottom) demand profiles (large hotel in Los 

Angeles) 

Winter Spring Summer Fall Winter

Winter Spring Summer Fall Winter
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Figure 12. AC Demand worksheet

1.4.3 Equipment Configuration

The Equipment Configuration section of the Project Setup worksheet prompts you to configure 

your CHP/CHHP and baseline systems. Click the Go To button adjacent to Equipment 

Configuration. This sends you to the Equipment Specification worksheet (see Figure 13). Here, 

you enter the technical specifications for the primary fuel cell system and—if you selected them 

as part of your system—supplementary heat supply, hydrogen storage, PV, wind turbines, 

electrolyzer, and hydrogen fuel cell. Some of the calculated values in this worksheet depend on 

profiles that you may already have created/imported (hydrogen demand, solar and wind 

availability); if you have not yet established these profiles, you have another opportunity to do so 

here.

The high-temperature fuel cell system is sized by specifying the maximum AC power output of 

the system; for the standard FCPower Model case studies, the maximum AC power output is set 

approximately to the average electricity demand. In general, it is advantageous to size the fuel 

cell for as high an output as possible while running the fuel cell close to its maximum power 

output as much of the time as possible. The model can be used to experiment with different fuel 

cell sizes to achieve the lowest cost. The reforming portion of the PAFC system also can be 

oversized to produce additional hydrogen by adjusting the reformer oversize factor. 

For PAFC systems, select Electricity Load Following or Heat Load Following using the radio 

buttons (see Figure 13). This determines the energy priority of your system. If you select 

Electricity Load Following, the system will make meeting electricity demand its top priority. If 

you select Heat Load Following, the system will make meeting heat demand its top priority. 

Note: this function is only available for the model based on the PAFC system. The MCFC and 

SOFC systems always make meeting electricity demand their top priority.

Demand profile year

Name of demand 

profile source file
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If the applicable technologies are activated, ensure values are present for the supplementary heat 

supply’s Maximum power, the electrolyzer’s Electrolyzer size, the hydrogen fuel cell’s Fuel cell 

capacity, the hydrogen storage system’s Total storage volume, the PV system’s PV array area, 

and the wind turbine’s Installed capacity. Note that you can select 350 or 700 bar (5,000 or 

10,000 psi) refueling pressure for the hydrogen storage system.

After entering or accepting the default specifications for each of the pieces of equipment in your 

system, it is recommended that you have the model analyze the system’s energy performance by 

clicking the Run Hourly Energy Profile button at the top of the worksheet. This will identify any 

equipment specifications that are not adequate for meeting your system’s energy needs and will 

ready the model for analyzing the financial performance of your system. When you have 

finished, click the Done button to return to the Project Setup worksheet. 

Figure 13. Equipment Specification worksheet (PAFC system model) 

Next, from the Project Setup worksheet, click the Go To button adjacent to Specify Baseline 

System. The baseline system provides energy for the building (and in the case of CHHP, 

hydrogen) from conventional sources assuming no onsite electricity production. The baseline 

system is used for energy supply cost comparison with the CHP/CHHP system and provides a 

baseline value for calculations of greenhouse gas and overall energy use reduction calculations. 

Electricity for the building is supplied from the grid using the same electricity source and price 

structure that is used for supply of supplementary electricity for the CHP/CHHP system. Heat is 

supplied using a conventional boiler or furnace using the same fuel as is used for the fuel cell 

system. Hydrogen, if applicable, is supplied using the technology you select from the Select 

Hydrogen Production System drop-down menu (e.g., distributed natural gas reforming). Note 

that you can select 350 or 700 bar (5,000 or 10,000 psi) hydrogen refueling for the baseline 

system.

1.4.4 Purchased Electricity Price

From the Project Setup worksheet, click the Go To button adjacent to Purchased Electricity 

Price, which sends you to the Grid Price Structure worksheet (see Figure 14). This worksheet 

accounts for hourly electricity price variations (e.g., higher prices during peak-demand times 
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such as 7:00 AM to 6:00 PM on workdays), seasonal rates, and demand charges. Accept the 

default values or enter new values for Usage Charges, Demand Charges, and Rate Periods. 

When finished, click the Calculate Sheet button to calculate grid prices based on your inputs. 

Note that the numbers in the columns at left are model calculations/results, not inputs, and are 

updated when the model is run. You only need to enter values at the top of the worksheet in the 

Usage Charges, Demand Charges, and Rate Periods sections. You can update the worksheet 

calculations by clicking the Calculate Sheet button, but this is not necessary; all calculations are 

run when the model is run. When finished with the Grid Price Structure worksheet, click the 

Done button to return to the Project Setup worksheet. 

Figure 14. Grid Price Structure worksheet

1.4.5 Capital and Operating Costs

From the Project Setup worksheet, click the Go To button adjacent to Capital and Operating 

Costs, which sends you to the Input worksheet (see Figure 15). The information you enter into 

the Input worksheet varies based on the configuration you selected. However, for all 

configurations, you are first prompted to enter fuel type and price information. Use the dropdown menus to select the fuel price table that the model will use, the fuel type, and the price 

units. The worksheet automatically generates fuel prices for each year of your system’s 

operation; view the yearly breakdown by clicking the Show Detail button. If you overwrite any 

of these yearly values with your own values and want to return to the model’s default 

calculations, click the Reset button. 
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Figure 15. Input worksheet (custom configuration) 

If you previously selected the custom configuration, after entering the fuel type and price 

information on the Input worksheet you are given another opportunity to import solar and wind 

availability profiles. The next step for all configurations is to enter information into the 

Operating Specifications and Costs section of the Input worksheet. The input sections are similar 

for each configuration, although there are more input fields as the system increases in complexity 

(from CHP to CHHP to custom). Accept the default values or enter new values into the orange 

cells. The contents of the blue cells are calculated automatically. In the Direct Capital Costs

section of the Input worksheet, you will see Enter Values, View/Edit, or Not Selected buttons 

next to the technologies that make up your system (see Figure 16). 
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Figure 16. Input worksheet, direct capital costs section

Click the first button, which is adjacent to the field High-temperature fuel cell and/or reformer 

process direct capital cost, to go to the Fuel Cell System worksheet. The most important value on 

this worksheet is the Fuel cell CHP equipment uninstalled cost at the top (see Figure 17). For 

help choosing this value, click the adjacent Cost guidance button. A window titled "Reference 

Material and Guidance for Fuel Cell System Cost Estimates" pops up (see screen capture below). 

Once you have read the information in the pop-up window and decided on a cost, close the 

window and fill in the mandatory field. Continue to make other changes on the Fuel Cell System

worksheet as necessary. Once you are done making changes to this technology, return to the 

Input worksheet using the Input Sheet button. Repeat this process for all activated technologies

(see Figure 18). Later, you can modify values on the detail worksheets using the View/Edit

button if necessary. 

Figure 17. Fuel Cell System worksheet, mandatory fuel cell uninstalled cost field

Deactivated 

technology 

Activated 

technologies 
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Figure 18. Example Technology Detail worksheet (electrolyzer)

As you continue to complete the Input worksheet, you will find fields for indirect capital costs, 

non-depreciable capital costs, fixed operating costs, and variable operating costs. In the Other 

Variable Operating Costs section, the factor you enter in the field Total unplanned replacement 

capital cost factor is transferred to the Replacement Costs worksheet, which calculates 

replacement costs based on this factor and the value for total depreciable capital costs. Go to the 

Replacement Costs worksheet if you want to specify additional replacement costs. Enter 

replacement costs for all selected technologies here. Specified replacement costs are depreciated 

on the same schedule as the original equipment. Unplanned replacement costs are depreciated on 

a 5-year Modified Accelerated Cost Recovery System (MACRS) schedule. The depreciation 

types and schedules can be changed in the Financial Input worksheet as described in the next 

section.

Accept the default values/calculations for all other fields or enter your own values, then click the 

Done button at the bottom of the worksheet to return to the Project Setup worksheet. 

1.4.6 Energy Analysis

After working down to the Run Energy Analysis section of the Project Setup worksheet, click the 

adjacent Run button (if you already ran the energy analysis as part of a previous step, you do not 

need to run it again here—you can proceed directly to the Financial Assumptions described in 

the next section). This prompts the model to run hourly energy calculations based on the system 

characteristics you have chosen and the energy demand and supply profiles in the AC Demand, 

Heat Demand, H2 Demand, and Solar and Wind Availability worksheets.

Capital cost value exported to 

Input worksheet

Input Sheet

button
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The hourly energy calculations can require a substantial amount of time to complete depending 

on the speed of your computer. A counter at the bottom of the worksheet shows the estimated 

modeling runtime. As the energy analysis is running, the model is completing each cell within 

the MODEL worksheet process flow diagram (invisibly) for each of 8,760 hours. It prioritizes the 

type of energy demand (electricity or heat) to meet, then prioritizes the energy sources used to 

meet the demand. For example, the high-temperature fuel cell system must always remain on and 

thus is always producing a minimum amount of electricity. If the model is set to follow electrical 

demand, it will meet the demand with this minimum fuel cell system electricity first plus PV or 

wind-generated electricity (if available). If there is still unmet electrical demand, the model will 

attempt to meet it by increasing the output of the fuel cell system and then using the lowtemperature hydrogen fuel cell. (Note: the electrolyzer and hydrogen fuel cell cannot both 

operate at the same time.) Finally, grid electricity is used to satisfy any demand that is still 

unmet.

1.4.7 Financial Assumptions

After the energy analysis has completed, click the Go To button adjacent to the Project Setup

worksheet’s last section—Financial Assumptions. This sends you to the Financial Input

worksheet. 

The information you enter into the Financial Input worksheet varies based on the entity type you 

selected previously (commercial/regulated utility or government/tax exempt). The 

commercial/regulated input includes tax incentive and depreciation fields, whereas the 

government/tax-exempt input does not include these fields. 

For all entity types, the project timeline is displayed at the top of the Financial Input worksheet. 

You do not need to modify the project timeline—it is imported here from the values you entered 

on the Project Setup worksheet. Next, for all entity types, enter or accept the default values in the 

Financial Basis Inputs, Fixed Operating Costs, and Other Variable Operating Costs sections. If 

you selected the government/tax-exempt entity type, you are now finished with the Financial 

Input worksheet. Click the Done button (at the bottom) to return to the Project Setup worksheet. 

If you selected the commercial/regulated entity type, continue to the tax incentive and 

depreciation sections of the Financial Input worksheet (see Figure 19). Several specific 

incentives are already listed (e.g., Federal business energy tax credit - fuel cells); click the Info

buttons to learn about these incentives. Click the Calculate buttons to calculate the incentives 

automatically for your system. If you overwrite these calculations with your own values, you can 

bring the original default calculations back by clicking the Calculate button twice. Continue 

entering values in the Other Incentives, Production Tax Credits, and Production Tax Credits 

Based on Emissions Reduction fields as applicable.
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Figure 19. Tax incentive fields in the Financial Input – Commercial worksheet

The tax incentive sections are followed by a section for setting depreciation types and schedules 

for your capital equipment. Depreciation type options include straight line, MACRS, and none. 

Selecting "none" sets the depreciable capital cost basis to zero; this is applicable to nonprofit 

organizations. If you overwrite the default values, you can bring them back by unchecking and 

rechecking the Default check boxes. If you enter a value in the last field in this section, 

Adjustment to depreciable capital for other one-time tax incentives, the value is subtracted from 

the total depreciable capital cost basis. Once you have completed all applicable fields in the 

Financial Input worksheet, click the Done button (at the bottom) to return to the Project Setup

worksheet. 

You are now done configuring your distributed energy system and are ready to calculate 

financial, energy, and emissions results. 

1.5 Calculating Financial, Energy, and Emissions Results

Return to the top of the Project Setup worksheet and click the Calculate Cost button (see Figure 

20). The model runs financial, energy, and emissions calculations based on the hourly energy 

results and the system and financial parameters you have chosen. You can change financial 

parameters and calculate new costs using the Calculate Cost button without running the energy 

analysis again, which minimizes processing time. However, if you want to change characteristics 

of your hourly energy calculations, you will need to click the Run button next to Run Energy 

Analysis again and allow the model to process the hourly calculations again before calculating 

new costs.
19 

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Figure 20. Project Setup worksheet (calculate cost button at top right)

When the model is done performing the cost calculations, it sends you to the Financial Analysis

worksheet. This worksheet contains a variety of financial summary information and results, 

including breakdowns of annual energy costs, levelized costs, lifecycle system costs, and 

payback periods. An energy value solver (see Figure 21) enables you to allocate the value of 

your system's total energy among the different energy types: electricity, heat, and hydrogen. 

Click the radio button corresponding to the energy type for which you want to calculate a value. 

Then, enter or accept the default values1

 for the two orange fields. The blue field corresponding 

to the radio button is calculated automatically, thus completing the allocation of values (in 

$/kWh) for each energy type. Also calculated are the value of hydrogen in $/kg and the total 

yearly value of each energy type. You can perform sensitivity analyses from the Financial 

Analysis worksheet (see Figure 22). Click the tab for the Energy and Emissions worksheet to 

view summary energy and emissions results (see Figure 23). Detailed results can be found in the 

HOURLY RESULTS worksheet.

 

1 The default value for electricity is the average electricity cost for your system if you had purchased all electricity 

from the grid. The default heat value is based on the cost of heating with natural gas (this is the same value as the 

cost of supplementary heating in the table below). The default hydrogen cost is based on the cost of hydrogen from a 

standalone SMR system, assuming the same cost of natural gas feedstock as for the high-temperature fuel cell. 
20 

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Figure 21. Financial Analysis worksheet, energy value solver

Figure 22. Financial Analysis worksheet, sensitivity analysis

Figure 23. Energy and Emissions worksheet, energy and GHG flows

Energy value 

solver 
21 

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In the FCPower Model results, the modeled system is compared to a “baseline” case for which 

building electricity is supplied by the grid, heat is supplied by a natural gas space heating and hot 

water system, and hydrogen is supplied by a standalone forecourt SMR and dispensing system. 

Costs for the baseline hydrogen production and dispensing system are derived from the H2A 

current timeframe distributed natural gas hydrogen production case study (Current Forecourt 

Hydrogen Production from Natural Gas [1,500 kg per day] version 3.0) published at 

www.hydrogen.energy.gov/h2a_prod_studies.html. The H2A case study was scaled to various 

sizes to derive the cost correlation equations used in the FCPower Model. The user can select 

either 350 bar refueling or 700 bar refueling for the baseline station.

1.6 Technical Support

Information related to the FCPower Model will be posted at

www.hydrogen.energy.gov/fc_power_analysis.html as it becomes publicly available. Also visit 

the website to download the most updated version of the model. For technical questions not 

answered by this guide or the website, contact: 

Darlene Steward, National Renewable Energy Laboratory 

303-275-3837, darlene.steward@nrel.gov
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2 Designs of the FCPower Model Fuel Cell Systems

2.1 Introduction

The FCPower Model simulates the performance of three types of CHP systems: one based on 

MCFCs, one based on PAFCs, and one based on SOFCs. Each type of fuel cell can be integrated 

with other components to operate as a CHP system alone or as a CHHP system that co-produces 

hydrogen. The CHHP system design has been developed for multiple platforms, but currently 

only a MCFC system has been built as a large-scale demonstration unit. 

The MCFC, PAFC, and SOFC system concepts were modeled using ASPEN Plus, a steady-state 

thermodynamics simulation software. ASPEN is an industry-standard software for modeling and 

designing chemical plants. It performs detailed mass and energy balances on various unit 

operations such as reactors, compressors, and condensers. The CHHP systems models use 

conventional industrial unit operations integrated into a novel system. The analysis assumes that 

near-term technology improvements currently under development are in place, the systems are 

fully integrated, and moderate production volumes have reduced costs from current stationary 

fuel cell installations.

The FCPower Model simulations were created using a two-step process. First, detailed and 

thermodynamically correct CHP/CHHP systems were designed using ASPEN Plus. Then, these 

detailed models were used to create simplified linear models of system performance within the 

FCPower Model framework so that FCPower results approximate the ASPEN results within a 

reasonable range of system performance.

This section describes the basic operation of MCFCs, PAFCs, and SOFCs and details the 

CHP/CHHP systems that were designed and modeled using ASPEN. It also discusses modeling 

of the fuel cell systems using the FCPower Model and the correlation of FCPower results with 

ASPEN model results. 

2.2 Molten Carbonate Fuel Cell System

Molten carbonate fuel cells use an electrolyte composed of a molten carbonate salt mixture 

suspended in a porous, chemically inert ceramic lithium aluminum oxide matrix [1]. Because 

they operate at extremely high temperatures (650°C and above), non-precious metals can be used 

as catalysts at the anode and cathode, which reduces costs.

Molten carbonate fuel cells can be more efficient than PAFCs, with efficiencies approaching 

50%, compared with 37%–42% for PAFCs. For MCFC configurations in which waste heat is 

used for additional electricity generation, electrical efficiencies greater than 60% are possible, 

and overall fuel efficiencies can be as high as 85%.

Unlike alkaline, phosphoric acid, and polymer electrolyte membrane fuel cells, MCFCs do not 

require an external reformer to convert fuels to hydrogen. Owing to the high operating 

temperature, fuels are converted to hydrogen within the fuel cell itself via SMR, which reduces 

system complexity. In addition, MCFCs are not prone to carbon monoxide (CO) poisoning; in 

fact, CO is used as fuel along with hydrogen (H2).
23 

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The primary disadvantage of current MCFC technology is durability. The high temperatures at 

which these cells operate and the corrosive electrolyte used accelerate component breakdown 

and corrosion, decreasing cell life. Corrosion-resistant component materials are being developed 

along with fuel cell designs that increase cell life without decreasing performance. Another 

disadvantage of MCFCs is their dynamic performance. Because the system must balance the fuel 

cell temperature while maintaining an even temperature distribution, long times are required for 

the temperature to distribute from one power level to another. 

2.2.1 Molten Carbonate Fuel Cell Operation 

The following description of MCFC operation is taken from the Fuel Cell Handbook, 7th edition 

[1]. See that reference for additional details. Figure 24 is a schematic of an MCFC's operating 

configuration. The following are the half-cell electrochemical reactions:

Equation 1. H2 + CO3

2- → H2O + CO2 + 2e- (at the anode)

Equation 2. 1⁄2O2 + CO2 + 2e- → CO3

2- (at the cathode)

The following is the overall cell reaction:

Equation 3. H2 + 1⁄2O2 + CO2 (cathode) → H2O + CO2 (anode)

Besides the reaction involving H2 and O2 to produce H2O, this equation shows a transfer of CO2

from the cathode gas stream to the anode gas stream via the CO3

2- ion. The need for CO2 at the 

cathode requires that either CO2 is transferred from the anode exit gas to the cathode inlet gas, 

CO2 is produced by combusting the anode exhaust gas (which is mixed directly with the cathode 

inlet gas), or CO2 is supplied from an alternate source. It is usual practice in an MCFC system 

that the CO2 generated at the anode (right side of Equation 1) be routed (external to the cell) to 

the cathode (left side of Equation 2).

Figure 24. Schematic of MCFC operation [1]
24 

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2.2.2 ASPEN Model of MCFC-CHP System

The MCFC-CHP system developed in ASPEN uses fuel, air, and water inputs to produce 

electricity and heat. Figure 25 is a generalized schematic of the system. Figure 46 and Table 1 at 

the end of this section show the detailed ASPEN process flow diagram and accompanying 

energy and material flows. Some of the key process steps are described below, numbered to 

correspond with the numbers in Figure 25. 

1. Water and fuel inputs: Water and fuel (e.g., natural gas) enter the system. The model 

uses a steam-to-carbon ratio of 1.5, which is typical of current industry applications. The 

feedstock is cleaned of contaminants that can degrade the system, such as sulfur (from

the fuel) and chlorides (from the water). The cleanup subsystems were not modeled in 

ASPEN, because multiple technologies could be used, and many of them do not affect the 

mass and energy balance of the system significantly. The purified water and fuel are 

vaporized before entering the fuel cell, where internal reforming produces a mixture 

containing H2 and CO. Heat for vaporizing the fuel and water is taken from the cathode 

exhaust stream.

2. MCFC electricity production: Seventy percent of the caloric content of the fuel 

entering the anode is used to make electricity via the reactions described in Equations 1–

3. This is a typical percentage used in current MCFC designs; it provides high 

performance while accounting for flow distribution and mass transport limitations in the 

anode. The fuel mixture not used to make electricity passes through the fuel cell to the 

burner. 

3. Burner and cathode air supply: Air supplied to the cathode has multiple functions. It 

oxidizes the anode exhaust to eliminate emissions. The burner exhaust contains the CO2

and O2 required for the cathode reaction. The burner air regulates the temperature of the 

fuel cell, carrying heat away from the fuel cell reaction (650°C). Heat from the cathode 

exhaust is then used for steam generation and providing heat output. 

4. Building heating system: Excess heat from the fuel cell is used to heat the building. In 

the ASPEN model, water enters the exhaust heat exchanger at 60°C, is heated to 80°C, 

and then is circulated to heat the building. Excess fuel cell heat not needed to heat the 

building is vented. This range of heat-recovery temperatures is most commonly seen in 

large building installations.

5. Power electronics: The inverter transforms DC electricity produced in the fuel cell to 

AC electricity. The 93% efficiency is typical of standard inverters available today. In 

addition, the power electronics typically supply the power required by the fuel cell 

blowers, pumps, and valves. 
25 

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Figure 25. Schematic of modeled MCFC-CHP system

2.2.3 ASPEN Model of MCFC-CHHP System

The MCFC-CHHP system developed in ASPEN uses fuel, air, and water inputs to produce 

electricity, heat, and hydrogen. It operates much like the CHP system discussed above, with the 

exception that hydrogen from the anode exhaust gas is enriched, separated, and compressed for 

storage and dispensing. The system operates in two modes. In the hydrogen production mode, 

70% of the caloric content of the fuel mixture entering the anode is used to make electricity (as 

in the CHP system), and 70% of the hydrogen in the anode exhaust gas is recovered and stored. 

In the hydrogen over-production mode, 60% of the caloric content of the fuel mixture entering 

the anode is used to make electricity, and 75% of the hydrogen in the anode exhaust gas is 

recovered and stored. Both modes reduce the amount of energy available for heating the 

building. Figure 26 is a generalized schematic of the system. Figure 46, Table 2, and Table 3 at

the end of this section show the detailed ASPEN process flow diagram and accompanying 

energy and material flows. Some of the key process steps are described below, numbered to 

correspond with the numbers in Figure 26. 

6. Anode exhaust shift reaction: Hydrogen produced via internal reforming in the fuel cell 

and not used to produce electricity exits the anode in the exhaust stream. This stream 

contains CO, H2, and H2O. The stream is cooled to ~300°C by using PSA exhaust. The 

gas then enters the shift catalyst, which converts CO and H2O to H2 via the following 

reaction: 

Equation 4. CO + H2O → CO2 + H2

7. Gas compression: Most of the water is removed from the gas stream by chilling to 

ambient temperatures, and the gas stream is compressed to 150 psig as per standard 

industry practice for PSA. A multi-stage compressor is used with a maximum 

compression ratio of 2:1 per stage and intercoolers to 25°C. In the ASPEN model, water 

is removed once again after the compression stage. 

1

2

3

4

5
26 

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8. Pressure swing adsorption (PSA): Hydrogen is recovered via PSA before being 

compressed to 6,250 psig for storage and dispensing. The remaining gas stream 

(including unrecovered H2) is returned to the burner. Although other hydrogen separation 

technologies, such as electrochemical hydrogen pumping, might eventually prove to be 

better suited to CHHP applications, PSA was selected for the model because of its market 

availability and expected use in the first commercial CHHP systems.

Figure 26. Schematic of modeled MCFC-CHHP system

2.2.4 Modeling MCFC Systems with the FCPower Model

The FCPower Model was designed with a linear model that mimics the performance of the 

ASPEN-modeled MCFC CHP/CHHP systems described above. The system tracks electricity 

demand, with heat and hydrogen as co-products. Hydrogen is the primary co-product and has 

production priority over heat. 

Most of the fuel cell system parameters—found in the Equipment Specification worksheet—are 

set automatically in the FCPower Model to match the system parameters established in the 

ASPEN models and to meet the FCPower energy demand profiles. Many users will not need to 

change any of the values on this worksheet. The technical values that can be changed by users 

are shown in orange in Figure 27 and described briefly below. 

6

8

7
27 

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Figure 27. FCPower Model MCFC Equipment Specification worksheet

Maximum electricity output rating—The default value for this field is set to the average 

electricity demand from the AC Demand worksheet. This is a reasonable first estimate for the 

fuel cell system's maximum electrical output. However, commercial MCFC systems are 

available in a limited range of sizes, so users might want to research currently available products 

and replace the default value with a value from one of these products. Optimal economic results 

are obtained when the fuel cell is sized to operate at nearly full power all the time. Note that 

system performance is scalable. For example, doubling the size of the fuel cell doubles the 

potential hydrogen production. This assumption is reasonable because the modeled fuel cell 

systems are large; thus their heat-loss effects are relatively small. 

Efficiency of H2 production—The efficiency of hydrogen production is defined as the kW of 

hydrogen produced from the fuel cell anode exhaust gas divided by the kW reduction in the 

available CHP (usable) heat [fuel used × (total efficiency – electrical efficiency)]. The default 

value is derived from the system modeled in ASPEN and accounts for the recovery of the PSA 

system and heat-quality reduction in the anode exhaust. Exhaust heat recovery is assumed with a 

60°–80°C cooling loop. Note that this definition of efficiency does not include auxiliaries 

required for running the PSA unit or compressing the hydrogen. Those inputs are accounted for 

within the MODEL worksheet. 

Efficiency of H2 over-production—The efficiency of hydrogen over-production is defined as 

the kW of hydrogen produced from addition of excess fuel divided by the kW of additional fuel 

consumed. The default value is derived from the system modeled in ASPEN. Note that this 

definition of efficiency does not include auxiliaries required for running the PSA unit or 

compressing the hydrogen. Those inputs are accounted for within the MODEL worksheet.

Maximum fraction of heat convertible to hydrogen—The maximum fraction of heat 

convertible to hydrogen is defined as the fraction of CHP heat that can be converted to hydrogen. 

The default value is derived from the system modeled in ASPEN.

Maximum amount of hydrogen over-production as fraction of H2 production—The 

maximum hydrogen over-production potential is defined as the fractional increase in the total 

amount of hydrogen that can be produced if more fuel is supplied to the fuel cell than is needed 

for electricity production at rated power. For example, a value of 0.5 means that for every kg/h of 

hydrogen produced an additional 0.5 kg/h of hydrogen can be over-produced by increasing fuel 
28 

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consumption of the system. Thus, a total of 1.5 kg/h of hydrogen would be produced while 

increasing the fuel consumption rate. The default value is derived from the system modeled in 

ASPEN.

AC efficiency—The default values for these fields are set based on the MCFC system modeled 

in ASPEN, but users can change the values (e.g., based on the specifications of a currently 

available system). Note that total efficiency always must be higher than electrical efficiency. 

Total efficiency—Values for total efficiency at part load are generated using the ASPEN model. 

Total efficiency is typically lower at low-power operation because fuel is consumed to maintain 

the operating temperature. Total efficiency depends largely on fuel cell exhaust temperature. For 

this ASPEN analysis, a heating loop of 60°–80°C (140°–176°F) is assumed: heat-recovery water 

enters from the building at 60°C and returns to the building at 80°C. This is a very common 

range for heating, but if, for example, a building requires 40°–60°C (104°–140°F) operation, this 

would result in better total efficiency because more heat would be captured from the exhaust. 

AC response time—This is the amount that the fuel cell electrical output can change per hour, 

e.g., a value of 10% means the AC output can change by a maximum of 10% per hour. 

Water for AC production—The default value for this field is based on the MCFC system 

modeled in ASPEN, but users can change it to any positive number, e.g., to match specifications 

of currently available systems. Note that, in general, less water is required for systems that 

operate in condensing conditions. If the exhaust is cooled sufficiently, condensed water can be 

used for fuel cell operation.

Water for H2 production—The default value for this field is based on the MCFC system 

modeled in ASPEN, but users can change it to any positive number, e.g., to match specifications 

of currently available systems. In the model, PSA is used for hydrogen purification. Water is 

extracted from the syngas before entering the PSA; therefore, less makeup water is typically

required in CHHP mode. 

Hydrogen purification auxiliaries—This defines the electrical power requirements for the 

compressor component of the PSA system. 

2.2.5 Correlation of MCFC ASPEN Model and FCPower Model 

Sensitivity analyses were performed to determine the correlation between results from the 

detailed MCFC system ASPEN model and the simplified model of system performance created 

for the FCPower Model. Figure 28 (CHP), Figure 29 (CHHP), and Figure 30 (CHHP with 

hydrogen over-production) contain ASPEN and FCPower Model results showing the electricity, 

heat, and hydrogen produced and fuel used at different fuel cell system power levels. The size of 

the system modeled is 1.4 MW. 

For each analysis, the correlation generally decreases as the system utilization decreases owing 

to the linear nature of the FCPower Model and the non-linear performance of fuel cells. 

FCPower Model results at system utilization levels below 20% do not correlate well with 

ASPEN results; therefore, system utilization rates below this level are not used in the FCPower 

Model. If energy demand drops below this level, the model continues to operate at 20%, and 
29 

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excess electricity is sold to the grid. Future versions of the FCPower Model may increase fit 

complexity to accommodate better system performance fit.

Figure 28. Correlation of ASPEN and FCPower Model results for MCFC-CHP system 

Figure 29. Correlation of ASPEN and FCPower Model results for MCFC-CHHP system

0

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30 

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Figure 30. Correlation of ASPEN and FCPower Model results for MCFC-CHHP system, H2 overproduction 

2.3 Phosphoric Acid Fuel Cell System

Phosphoric acid fuel cells use liquid phosphoric acid as an electrolyte—the acid is contained in a 

Teflon-bonded silicon carbide matrix—and porous carbon electrodes containing a platinum 

catalyst [1]. The PAFC is considered the "first generation" of modern fuel cells. It is one of the 

most mature cell types and the first to be used commercially. This type of fuel cell is typically 

used for stationary power generation, but some PAFCs have been used to power large vehicles 

such as city buses.

Phosphoric acid fuel cells are more tolerant of impurities in reformed fossil fuels than are PEM 

fuel cells, which are easily "poisoned" by CO and hydrogen sulfide (H2S). At lower 

temperatures, CO and H2S bind to catalyst surfaces, masking the catalyst from use for hydrogen 

dissociation. This problem is reduced in PAFCs because they operate at approximately 200°C. 

PAFCs have a lower power density than most other fuel cell types; however, they have 

significantly longer lifetimes, about 10 years for state-of-the-art stacks. The electrical efficiency 

of PAFC systems is typically about 40% at the beginning of their lives and at rated power. This 

is only slightly more efficient than combustion-based power plants, which typically operate at 

33%–35% efficiency, but the distributed nature of CHP systems avoids electrical transmission 

losses. Depending on heat recovery, the total efficiency of PAFC systems can reach 85% in CHP 

mode. 

2.3.1 Phosphoric Acid Fuel Cell Operation

The following description of PAFC operation is taken from the Fuel Cell Handbook, 7th edition 

[1]. See that reference for additional details. Figure 31 is a schematic of a PAFC's operating 

configuration. The following are the half-cell electrochemical reactions:

Equation 5. H2 → 2H+

 + 2e- (at the anode)

Equation 6. 1⁄2O2 + 2H+

 + 2e- → H2O (at the cathode)

0

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H2 Produced - ASPEN

H2 Produced - FCPower
31 

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The following is the overall cell reaction:

Equation 7. 1⁄2O2 + H2 → H2O 

The electrochemical reactions occur on highly dispersed electro-catalyst particles supported on 

carbon black. Platinum or platinum alloys are used as the catalyst at both electrodes. 

Figure 31. Schematic of PAFC operation [2]

Natural gas (CH4) is the most commonly used fuel for PAFC systems. It is converted to 

hydrogen and used to produce electricity via the following reactions: 

Equation 8. CH4 + 2H2O → 4H2 + CO2 (reforming reaction)

Equation 9. 4H2 → 8H+

 + 8e- (anode reaction) 

Equation 10. 2O2 + 8H+ + 8e- → 4H2O (cathode reaction)

Combining these equations gives the overall reaction of methane combustion: 

Equation 11. CH4 + 2O2 → CO2 + 2H2O (overall reaction) 

2.3.2 ASPEN Model of PAFC-CHP System

The PAFC-CHP system developed in ASPEN uses fuel, air, and water inputs to produce 

electricity and heat. Figure 32 is a generalized schematic of a PAFC system. Figure 47 and Table 

4 at the end of this section show the detailed ASPEN process flow diagram and accompanying 

stream table. Some of the key process steps are described below, numbered to correspond with 

the numbers in Figure 32. 

1. Water and fuel inputs: Water and fuel (e.g., natural gas) enter the system. The model 

uses a H2O-to-CH4 ratio of 3.0, which is typical of current industry practices. The 
32 

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feedstock is cleaned of contaminants that can degrade the system, such as sulfur (from 

the fuel) and salts (from the water). The cleanup subsystems were not modeled in ASPEN 

because multiple technologies could be used, and many of them do not affect the mass 

and energy balance of the system significantly. Water is vaporized in the fuel cell stack's 

coolers, which serves to cool the fuel cell stack in addition to producing the steam needed 

for the reformer.

2. Steam-methane reforming: The SMR is a heat exchanger with two reactions occurring 

on each side. On the reforming side, fuel and steam are reformed to produce CO and H2. 

The reforming reaction temperature in the model is 700°C. Because this reaction is 

endothermic, the opposing side of the heat exchanger combusts depleted and fresh fuel at 

750°C to provide sufficient heat for the reforming. It is assumed that reformate exhaust is 

also used to preheat the steam and fuel mixture before the mixture enters the reformer, 

and burner exhaust is used to preheat the burner air. 

3. Shift reaction: The stream exiting the reformer contains H2, CO, CO2, and H2O. This 

stream enters the shift catalyst, which operates at 270°C (at low power) or 310°C (at high 

power) and converts CO and H2O to H2 via the following reaction: 

Equation 12. CO + H2O → CO2 + H2

4. PAFC electricity production: Hydrogen is supplied to the anode at a stoichiometric 

ratio of 1.15 (i.e., 15% more H2 is present than can react with the amount of O2 present). 

Of the fuel entering the anode, 87% is used to make electricity via the reactions described 

in Equations 5–7. The polarization curve is defined by a linear relationship with cell 

voltage of 0.77 V at minimum power (100 kW) and 0.675 V at maximum power (400 

kW). The depleted reformate from the anode exhaust is fed to the burner. 

5. Cathode air supply and water recovery: Air is supplied to the cathode at a 

stoichiometric ratio of 2.0 (i.e., twice as much O2 is fed than stoichiometrically needed to 

react with the amount of H2 consumed). Water created via the cathode reaction is 

recovered if the fuel cell exhaust is cooled to a sufficiently low temperature (~50°C). If 

the exhaust is not cooled sufficiently, product vapor escapes, and makeup water is fed 

into the system. 

6. Building heating system: Excess heat from the fuel cell is used for heat cogeneration. In 

the ASPEN model, water enters the fuel cell heat recovery subsystem at 60°C and is 

heated to 80°C before returning to the facility. Heat is captured first from the exhaust to 

ensure the maximum possible condensation and overall heat recovery. Excess heat from 

the stack is then captured by cooling excess steam and water exiting the fuel cell coolers. 

7. Power electronics: The inverter transforms DC electricity produced in the fuel cell into

AC electricity. An efficiency of 93% is assumed for this conversion; higher efficiencies 

are possible for large applications. In addition, the power electronics typically supply the 

power required by the fuel cell blowers, pumps, and valves. Within the ASPEN model, 

some power is used for fixed electrical draws such as control systems, cabinet ventilation, 

solenoids, and fixed-speed auxiliaries.
33 

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Figure 32. Schematic of modeled PAFC-CHP system

2.3.3 ASPEN Model of PAFC-CHHP System

The PAFC-CHHP system developed in ASPEN uses fuel, air, and water inputs to produce 

electricity, heat, and hydrogen. It operates much like the CHP system discussed above, with the 

exception that some of the reformate output from the shift reaction is diverted for purification 

and storage. In addition, a supplementary burner is added to supplement the heat needed for 

steam generation. This reduces the amount of energy available for producing electricity and 

heating the building. Figure 33 is a generalized schematic of the system. Figure 47 and Table 5 at 

the end of this section show the detailed ASPEN process flow diagram and accompanying 

energy and material flows. Some of the key process steps are described below, numbered to 

correspond with the numbers in Figure 33. 

8. Gas diversion and compression: Some of the reformate stream exiting the shift reaction 

is diverted away from the fuel cell stack. Most of the water is removed from the stream 

by chilling to ambient temperatures, and the stream is compressed to 150 psig as per 

standard industry practice for PSA. A multi-stage compressor is used with a maximum 

compression ratio of 2:1 per stage and intercoolers to 25°C. In the ASPEN model, water 

is removed once again after the compression stage.

9. Pressure swing adsorption (PSA): About 75% of the hydrogen in the gas stream is 

recovered via PSA before being compressed to 6,250 psig for storage and dispensing. 

The remaining gas stream (including unrecovered H2) is fed to the burner. Although other 

hydrogen separation technologies, such as electrochemical hydrogen pumping, might 

eventually prove to be better suited to CHHP applications, PSA was selected for the 

model because of its market availability.

1

1

2

3 4

5

6 6

7
34 

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10. Supplementary heat: When steam is produced for normal fuel cell applications, it is 

generated mostly using heat from the fuel cell stack. However, if H2 production is high 

and electricity production is low, additional steam heat must be generated. 

Figure 33. Schematic of modeled PAFC-CHHP system

2.3.4 Modeling PAFC Systems with the FCPower Model

The FCPower Model was designed with a linear model that mimics the performance of the 

ASPEN-modeled PAFC CHP/CHHP systems described above. The model can make meeting 

electricity demand (input via the AC Demand worksheet) or heat demand (Heat Demand

worksheet) the highest priority; this is selected via the radio buttons in the Equipment 

Specification worksheet. 

Most of the fuel cell system parameters—found in the Equipment Specification worksheet—are 

set to default values in the FCPower Model to match the system parameters established in the 

ASPEN models. Most users will not need to change any of the values on this worksheet other 

than the fuel cell capacity. The technical values that can be changed by users are shown in 

orange in Figure 34 and described briefly below. 

8

9

10
35 

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Figure 34. FCPower Model PAFC Equipment Specification worksheet

Maximum electric output rating—The default value for this field is set to the average 

electricity demand from the AC Demand worksheet. This is a reasonable first estimate for the 

fuel cell system's maximum electrical output. However, commercial PAFC systems are available 

in a limited range of sizes, so users might want to research currently available products and 

replace the default value with a value from one of these products. Optimal economic results are 

obtained when the fuel cell is sized to operate at nearly full power all the time. Note that system 

performance is scalable. For example, doubling the size of the fuel cell doubles the potential 

hydrogen production. This assumption is reasonable because the modeled fuel cell systems are 

large; thus their heat-loss effects are relatively small.

Minimum electric output rating—The FCPower Model provides a close match to the ASPENmodeled fuel cell system down to a minimum system utilization of 40%; thus the default 

minimum electric output rating is set to 40% of the maximum electric output rating. This value 

can be changed, but it should only be increased, not decreased, because the model may not return 

accurate results below the 40% value. 

Reformer oversize factor—This value is a multiplier of the amount of reforming required for 

maximum electrical output. A reformer oversize factor of 1.0 means the exact amount of fuel is 

reformed as is needed to enable maximum electrical output only. A reformer oversize factor of 

2.0 means twice the amount of fuel is reformed as is needed for maximum electrical output and 

so forth. 

Efficiency of hydrogen co-production—The efficiency of hydrogen co-production is defined as 

the kW of hydrogen produced from addition of excess fuel divided by the kW of additional fuel 

consumed. The default value is derived from the system modeled in ASPEN. 

Heat de-rating from H2 co-production—The PAFC reforming process requires heat for 

reforming and steam generation. In typical operation, excess heat is available after the reforming 

process has been satisfied. This heat is available as a co-product. However, if additional 

hydrogen is co-produced, steam generation requires some of the excess heat to be diverted for 

the additional reforming requirement. Thus, heat output is reduced when the fuel cell coproduces hydrogen. This effect is proportional; for example, doubling the hydrogen coproduction doubles the heat requirement. This effect is captured in the model by the coefficient
36 

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(kW reduction in usable heat output per kW of hydrogen produced) in the Heat de-rating from 

H2 co-production field. The effect was modeled using ASPEN, and the results were used to

determine the value for this coefficient.

Electrical efficiency—The default values for these fields are set based on the PAFC system 

modeled in ASPEN, but users can change the values (e.g., based on the specifications of a 

currently available system). Note that total efficiency always must be higher than electrical 

efficiency. 

Total efficiency—Values for total efficiency at part load are generated using the ASPEN model. 

Total efficiency is typically lower at low-power operation because fuel is consumed to maintain 

the operating temperature. Total efficiency depends largely on fuel cell exhaust temperature. For 

this ASPEN analysis, a heating loop of 60°–80°C (140°–176°F) is assumed: heat-recovery water 

enters from the building at 60°C and returns to the building at 80°C. This is a very common 

range for heating, but if, for example, a building requires 40°–60°C (104°–140°F) operation, this 

would result in better total efficiency because more heat would be captured from the exhaust.

The usable heat fraction for the MCFC system is higher than for the PAFC system because the 

PAFC system operates at a lower temperature.

AC response time—This is the amount that the fuel cell electrical output can change per hour, 

e.g., a value of 10% means the AC output can change by a maximum of 10% per hour. The 

default value is 100%. Unlike the MCFC system, the default PAFC system can change 

instantaneously to any electrical output level between the minimum and maximum output 

ratings. 

Water for AC production—The default value for this field is based on the PAFC system 

modeled in ASPEN, but users can change it to any positive number, e.g., to match specifications 

of currently available systems. Note that, in general, less water is required for systems that 

operate in condensing conditions. If the exhaust is cooled sufficiently, condensed water can be 

used for fuel cell operation.

Water for H2 production—The default value for this field is based on the PAFC system 

modeled in ASPEN, but users can change it to any positive number, e.g., to match specifications 

of currently available systems. In the model, PSA is used for hydrogen purification. Water is 

extracted from the syngas before entering the PSA; therefore, less makeup water is typically

required in CHHP mode. 

2.3.5 Correlation of PAFC ASPEN Model and FCPower Model

Sensitivity analyses were performed to determine the correlation between results from the 

detailed PAFC system ASPEN model and the simplified model of system performance created 

for the FCPower Model. Figure 35 (CHP) and Figure 36 (CHHP) contain ASPEN and FCPower 

Model results showing the fuel, electricity, hydrogen, and high-quality heat flows and 

efficiencies at different fuel cell system utilization levels. FCPower Model results at system 

utilization levels below 40% do not correlate well with ASPEN results; therefore, system

utilization rates below this level are not used in the FCPower Model. If energy demand drops 

below this level, the model continues to operate at 40%, and excess electricity is sold to the grid. 
37 

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Figure 35. Correlation of ASPEN and FCPower Model results for PAFC-CHP system

Figure 36. Correlation of ASPEN and FCPower Model results for PAFC-CHHP system

0

200

400

600

800

1,000

1,200

0% 20% 40% 60% 80% 100%

Percent of Rated Power

Fuel Used/Energy Out (kW)

ASPEN H2 out

FCPower H2 out

ASPEN HQ heat out

FCPower HQ heat out

ASPEN fuel used

FCPower fuel used

ASPEN electricity out

FCPower electricity out

0%

10%

20%

30%

40%

50%

60%

70%

0% 20% 40% 60% 80% 100%

Percent of Rated Power

Efficiency

ASPEN electrical efficiency

FCPower electrical efficiency

ASPEN total efficiency

FCPower total efficiency

-200

0

200

400

600

800

1,000

1,200

0% 10% 20% 30% 40% 50% 60% 70% 80% 90% 100%

Percent of Rated Power

Fuel Used/Energy Out (kW)

ASPEN H2 out

FCPower H2 out

ASPEN HQ heat out

FCPower HQ heat out

ASPEN fuel used

FCPower fuel used

ASPEN electricity out

FCPower electricity out
38 

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2.4 Solid Oxide Fuel Cell System

Solid oxide fuel cells use an electrolyte composed of a solid, non-porous metal oxide, usually 

Y2O3-stablilized ZrO2 [1]. They operate at 600°–1,000°C, at which temperatures ionic 

conduction by oxygen ions takes place. Typically, the anode is a Ni-ZrO2 cermet, and the 

cathode is Sr-doped LaMnO3. Because the SOFC electrolyte is solid, there are no materialcorrosion or electrolyte-management problems associated with liquid electrolytes. However, the 

high operating temperatures place stringent requirements on the materials. 

A wide range of fuels, including various hydrocarbon fuels, can be converted by SOFCs. The 

high operating temperatures allow for high-efficiency power conversion, internal reforming, and 

high-quality byproduct heat for cogeneration or use in a bottoming cycle. Simple-cycle and 

hybrid SOFC systems have demonstrated efficiencies that are among the highest of any powergeneration system in addition to minimal air pollutant emissions and low greenhouse gas 

emissions. These capabilities make SOFCs an attractive emerging technology for stationary 

power generation ranging from 2 kW to 100s of megawatts of capacity. 

More recently, planar SOFC systems with high power densities operating at lower temperatures 

(700°–850°C instead of the previous norm of 900°–1,000°C) have been developed, which 

enables the use of less-expensive materials. This could improve the economics of SOFC 

applications ranging from small-scale stationary power (down to ~2 kW) to auxiliary power units 

for vehicles and mobile generators. SOFCs could eventually be used to supply part of the prime 

power in vehicles. The key technical challenge is to produce robust, high-performance SOFC 

stack technologies using suitable low-cost materials and fabrication methods. Derivatives from 

SOFC technology, such as automobile oxygen sensors, are already in widespread commercial 

use.

2.4.1 Solid Oxide Fuel Cell Operation 

The following description of SOFC operation is taken from the Fuel Cell Handbook, 7th edition 

[1]. See that reference for additional details. Figure 37 is a schematic of an SOFC operating 

configuration. The following are the half-cell electrochemical reactions:

Equation 13. H2 → 2H+

 + 2e- (at the anode)

Equation 14. 1⁄2O2 + 2H+

 + 2e- → H2O (at the cathode) 

The following is the overall cell reaction:

Equation 15. 1⁄2O2 + H2 → H2O 
39 

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Figure 37. Schematic of SOFC operation [2]

Natural gas (CH4) is the most commonly used fuel for SOFC systems. It is converted to 

hydrogen and used to produce electricity via the following reactions: 

Equation 16. CH4 + 2H2O → 4H2 + CO2 (reforming reaction)

Equation 17. 4H2 → 8H+

 + 8e- (anode reaction)

Equation 18. 2O2 + 8H+ + 8e- → 4H2O (cathode reaction)

Combining these equations gives the overall reaction of methane combustion: 

Equation 19. CH4 + 2O2 → CO2 + 2H2O (overall reaction)

2.4.2 ASPEN Model of SOFC-CHP System

The SOFC-CHP system developed in ASPEN uses fuel and air inputs to produce electricity and 

heat. Figure 38 is a generalized schematic of a SOFC system. Figure 48 and Table 6 at the end of 

this section show the detailed ASPEN process flow diagram and accompanying stream table. 

Some of the key process steps are described below, numbered to correspond with the numbers in 

Figure 38. 

1. Fuel input and water content: Fuel (e.g., natural gas) enters the system. Anode exhaust 

recycle of 65% achieves an H2O-to-CH4 ratio of 2.5–3.0, which is typical of current 

industry practices. The feedstock is cleaned of contaminants that can degrade the system, 

such as sulfur (from the fuel) and salts (from the water). The cleanup subsystems were 

not modeled in ASPEN because multiple technologies could be used, and many of them 

do not affect the mass and energy balance of the system significantly. 

2. Steam-methane reforming: The SMR partially (20%) reforms the fuel (CH4) to produce 

CO and H2. The reforming reaction temperature in the model is 700°C. Because this 

reaction is endothermic, the anode exhaust gas is used to preheat the steam and fuel 
40 

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mixture up to a sufficient temperature for the catalytic reactor. Partial pre-reform is done 

to limit the temperature gradient in the fuel cell from the endothermic reforming of CH4

and the exothermic electrochemical reactions.

3. Cathode air supply: Air is supplied to the cathode at a stoichiometric ratio of 3.2 (i.e., 

~3 times as much O2 is fed than stoichiometrically needed to react with the amount of H2

consumed). The extra air is used to cool the fuel cell and limit the temperature rise in the 

fuel cell stack to about 150°C. The air is preheated to a favorable catalytic reaction 

temperature by recuperation with the cathode exhaust (depleted-O2 air). The cathode 

exhaust is then used as an oxidant for the tail gas combustion. 

4. SOFC electricity production: Hydrogen is supplied to the anode at a stoichiometric 

ratio of 1.77 (i.e., 77% more H2 is present than can react with the amount of O2 present). 

The anode exhaust recycle of 65% brings the total fuel cell fuel utilization up to 78% 

(i.e., the total percentage of fuel converted to electricity by the fuel cell is 78% via the 

reactions described in Equations 13–15). The polarization curve is defined by a linear 

relationship with cell voltage of 0.78 V at maximum power (1,000 kW) and 0.84 V at 

minimum power (250 kW). The depleted reformate from the anode exhaust is fed to the 

burner after heat recuperation. 

5. Building heating system: Excess heat—from the fuel cell and from combustion of 

unused fuel in the anode tail gas with the air from the cathode exhaust—is used for heat 

cogeneration. In the ASPEN model, water enters the fuel cell heat recovery subsystem at 

60°C and is heated to 80°C before returning to the facility.

6. Power electronics: The inverter transforms DC electricity produced in the fuel cell into 

AC electricity. An efficiency of 93% is assumed for this conversion; higher efficiencies 

are possible for large applications. In addition, the power electronics typically supply the 

power required by the fuel cell blowers, pumps, and valves. Within the ASPEN model, 

some power is used for fixed electrical draws such as control systems, cabinet ventilation, 

solenoids, and fixed speed auxiliaries. These extra factors are accounted for by an 

additional 5% power loss. 
41 

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Figure 38. Schematic of modeled SOFC-CHP system

2.4.3 ASPEN Model of SOFC-CHHP System

The SOFC-CHHP system developed in ASPEN uses fuel and air inputs to produce electricity, 

heat, and hydrogen. It operates much like the CHP system discussed above with the exception 

that some of the anode exhaust gas goes through a shift reaction and is diverted for purification 

and storage of hydrogen. This reduces the amount of energy available for producing heat to the 

building, but the electricity production from the SOFC is independent of the heat recovery and 

hydrogen-capture processes, so it is not affected. Figure 39 is a generalized schematic of the 

system. Figure 48 and Table 7 at the end of this section show the detailed ASPEN process flow 

diagram and accompanying energy and material flows. Some of the key process steps are 

described below, numbered to correspond with the numbers in Figure 39. 

7. Shift reaction: The anode exhaust stream contains H2, CO, CO2, and H2O. This stream 

enters the shift catalyst, which operates at around 300°C and converts CO and H2O to H2

and CO2 via the following reaction:

Equation 20. CO + H2O → CO2 + H2

8. Gas diversion and compression: A controlled amount of shifted anode exhaust gas gets 

diverted before the burner, and the stream is compressed to 150 psig as per standard 

industry practice for PSA. A multi-stage compressor is used with a maximum 

compression ratio of 2:1 per stage and intercoolers to 25°C. In the ASPEN model, water 

is removed once again after the compression stage.

9. Pressure swing adsorption (PSA): About 85% of the hydrogen in the gas stream is 

recovered via PSA before being compressed to 6,250 psig for storage and dispensing. 

The remaining gas stream (including unrecovered hydrogen) is fed to the burner. 

Although other hydrogen-separation technologies, such as electrochemical hydrogen 

Reformer

Cathode

Anode

ac

Burner

dc

Fuel Cell

1

2

3 4

5

6
42 

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pumping, might eventually prove to be better suited to CHHP applications, PSA was 

selected for the model because of its market availability. 

Figure 39. Schematic of modeled SOFC-CHHP system

2.4.4 Modeling SOFC Systems with the FCPower Model

The FCPower Model was designed with a linear model that mimics the performance of the 

ASPEN-modeled SOFC CHP/CHHP systems described above. The system tracks electricity 

demand, with heat and hydrogen as co-products. Hydrogen is the primary co-product and has 

production priority over heat. 

Most of the fuel cell system parameters—found in the Equipment Specification worksheet—are 

set automatically in the FCPower Model to match the system parameters established in the 

ASPEN models and to meet the FCPower energy demand profiles. Many users will not need to 

change any of the values on this worksheet. The technical values that can be changed by users 

are shown in orange in Figure 40 and described briefly below. 

Reform

Cathode

Anode

ac

Burner

dc

Fuel Cell

Shift PSA

storage

hydrogen

7

8

9
43 

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Figure 40. FCPower Model SOFC Equipment Specification worksheet

Maximum electricity output rating—The default value for this field is set to the average 

electricity demand from the AC Demand worksheet. This is a reasonable first estimate for the 

fuel cell system's maximum electrical output. However, commercial SOFC systems are available 

in a limited range of sizes, so users might want to research currently available products and 

replace the default value with a value from one of these products. Optimal economic results are 

obtained when the fuel cell is sized to operate at nearly full power all the time. Note that system 

performance is scalable. For example, doubling the size of the fuel cell doubles the potential 

hydrogen production. This assumption is reasonable because the modeled fuel cell systems are 

large; thus their heat-loss effects are relatively small. 

Efficiency of H2 production—The efficiency of hydrogen production is defined as the kW of 

hydrogen produced from the fuel cell anode exhaust gas divided by the kW reduction in the 

available CHP (usable) heat [fuel used × (total efficiency – electrical efficiency)]. The default 

value is derived from the system modeled in ASPEN and accounts for the recovery of the PSA 

system and heat-quality reduction in the anode exhaust. Exhaust heat recovery is assumed with a 

60°–80°C cooling loop. Note that this definition of efficiency does not include auxiliaries 

required for running the PSA unit or compressing the hydrogen. Those inputs are accounted for 

within the MODEL worksheet. 

Efficiency of H2 over-production—The efficiency of hydrogen over-production is defined as 

the kW of hydrogen produced from addition of excess fuel divided by the kW of additional fuel 

consumed. The default value is derived from the system modeled in ASPEN. Note that this 

definition of efficiency does not include auxiliaries required for running the PSA unit or 

compressing the hydrogen. Those inputs are accounted for within the MODEL worksheet. 

Maximum fraction of heat convertible to hydrogen—The maximum fraction of heat 

convertible to hydrogen is defined as the fraction of CHP heat that can be converted to hydrogen. 

The default value is derived from the system modeled in ASPEN.

Maximum amount of hydrogen over-production as fraction of H2 production—The 

maximum hydrogen over-production potential is defined as the fractional increase in the total 

amount of hydrogen that can be produced if more fuel is supplied to the fuel cell than is needed 

for electricity production at rated power. For example, a value of 0.5 means that for every kg/h of 
44 

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hydrogen produced an additional 0.5 kg/h of hydrogen can be over-produced by increasing fuel 

consumption of the system. Thus, a total of 1.5 kg/h of hydrogen would be produced while 

increasing the fuel consumption rate. The default value is derived from the system modeled in 

ASPEN. 

AC efficiency—The default values for these fields are set based on the SOFC system modeled in 

ASPEN, but users can change the values (e.g., based on the specifications of a currently 

available system). Note that total efficiency always must be higher than electrical efficiency.

Total efficiency—Values for total efficiency at part load are generated using the ASPEN model. 

Total efficiency is typically lower at low-power operation because fuel is consumed to maintain 

the operating temperature. Total efficiency depends largely on fuel cell exhaust temperature. For 

this ASPEN analysis, a heating loop of 60°–80°C (140°–176°F) is assumed: heat-recovery water 

enters from the building at 60°C and returns to the building at 80°C. This is a very common 

range for heating, but if, for example, a building requires 40°–60°C (104°–140°F) operation, this 

would result in better total efficiency because more heat would be captured from the exhaust. 

AC response time—This is the amount that the fuel cell electrical output can change per hour, 

e.g., a value of 10% means the AC output can change by a maximum of 10% per hour. 

Water for AC production—The default value for this field is based on the SOFC system 

modeled in ASPEN, but users can change it to any positive number, e.g., to match specifications 

of currently available systems. Note that, in general, less water is required for systems that 

operate in condensing conditions. If the exhaust is cooled sufficiently, condensed water can be 

used for fuel cell operation. 

Water for H2 production—The default value for this field is based on the SOFC system 

modeled in ASPEN, but users can change it to any positive number, e.g., to match specifications 

of currently available systems. In the model, PSA is used for hydrogen purification. Water is 

extracted from the syngas before entering the PSA; therefore, less makeup water is typically 

required in CHHP mode. 

Hydrogen purification auxiliaries—This defines the electrical power requirements for the 

compressor component of the PSA system. 

2.4.5 Correlation of SOFC ASPEN Model and FCPower Model 

Sensitivity analyses were performed to determine the correlation between results from the 

detailed SOFC system ASPEN model and the simplified model of system performance created 

for the FCPower Model. Figure 41 (CHP), Figure 42 (CHHP), and Figure 43 (CHHP with 

hydrogen over-production) contain ASPEN and FCPower Model results showing the electricity, 

heat, and hydrogen produced and fuel used at different fuel cell system power levels. The size of 

the system modeled is 1 MW.

For each analysis, the correlation generally decreases as the system utilization decreases owing 

to the linear nature of the FCPower Model and the non-linear performance of fuel cells. 

FCPower Model results at system utilization levels below 20% do not correlate well with 

ASPEN results; therefore, system utilization rates below this level are not used in the FCPower 
45 

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Model. If energy demand drops below this level, the model continues to operate at 20%, and 

excess electricity is sold to the grid. Future versions of the FCPower Model may increase fit 

complexity to accommodate better system performance fit.

Figure 41. Correlation of ASPEN and FCPower Model results for SOFC-CHP system

Figure 42. Correlation of ASPEN and FCPower Model results for SOFC-CHHP system

Figure 43. Correlation of ASPEN and FCPower Model results for SOFC-CHHP system, H2 overproduction

2.5 FCPower Model Energy Balance 

Like the detailed ASPEN models, the FCPower Model meets system energy balance 

requirements. Figure 44 shows the working portion of the FCPower Model hourly energy model, 

a linear, numerically solved representation of the system performance modeled in ASPEN.

Energy balance is established for each hour, and subsystems are dispatched depending on 

0

100

200

300

400

500

600

700

0

200

400

600

800

1000

1200

1400

1600

1800

2000

0 200 400 600 800 1000 1200

Heat Produced (kW)

Fuel Used (kW)

AC Demand (kW)

Fuel Used - ASPEN

Fuel Used - FCPower

Heat Produced -ASPEN

Heat Produced -FCPower

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

0

200

400

600

800

1000

1200

0 200 400 600 800 1000 1200

Hydrogen Produced (kW)

Electricity Produced

AC Demand (kW)

Electricity Produced - ASPEN

Electricity Produced -FCPower

H2 Produced -ASPEN

H2 Produced -FCPower

0

50

100

150

200

250

0

500

1000

1500

2000

2500

0 200 400 600 800 1000 1200

Heat Produced (kW)

Fuel Used (kW)

AC Demand (kW)

Fuel Used - ASPEN

Fuel Used -FCPower 

Heat Produced -

ASPEN

Heat Produced -

FCPower

0

50

100

150

200

250

300

350

400

0

200

400

600

800

1000

1200

0 200 400 600 800 1000 1200

Hydrogen Produced (kW)

Electricity Produced

AC Demand (kW)

Electricity Produced -

ASPEN

Electricity Produced -

FCPower

H2 Produced -ASPEN

H2 Produced -FCPower

0

500

1000

1500

2000

2500

0 200 400 600 800 1000 1200

Fuel Used (kW)

AC Demand (kW)

Fuel Used - ASPEN

Fuel Used -FCPower 

0

100

200

300

400

500

600

700

0

200

400

600

800

1000

1200

0 200 400 600 800 1000 1200

Hydrogen Produced (kW)

Electricity Produced

AC Demand (kW)

Electricity Produced - ASPEN

Electricity Produced -FCPower

H2 Produced -ASPEN

H2 Produced -FCPower
46 

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demand. Because the fuel cell system has the most complex calculations, the energy balance of 

this subsystem is described below. 

The fuel cell system uses fuel (e.g., natural gas) as an energy feedstock. The chemical energy of 

the fuel is converted within the fuel cell system to three product streams: electricity, heat, and 

hydrogen. The fuel cell generates its own auxiliary power (e.g., blowers and pumps); thus, no 

auxiliaries are monitored outside the fuel cell. Fuel cell systems are not 100% efficient. The 

energetic sum of all the products is always lower than the energy inputs. Within this simplified 

model of fuel cell system performance, three waste energy streams are accounted for:

• Fixed heat loss (fixed amount of unrecoverable energy)

• Unusable heat (unrecoverable energy proportional to thermal input) 

• Inverter loss (energy loss associated with power electronics)

In this example, the energy balance of the fuel cell is the sum of all energy flows through the 

dotted line system boundary: 

Net energy flow = (fuel in) – (electricity out) – (usable heat out) – (hydrogen out) – (unusable 

heat) 

The following are the example model values (in kW): 

Fuel in = +491 

Electricity out = -200 

Usable heat out = -48 

Hydrogen out = -128 

Unusable heat = -115 

Net energy flow = 0.00 

An energy balance calculation also can be performed for the entire system (Figure 45). In this 

example, wind, solar, and grid power are used, and hydrogen is stored. Note that auxiliary power 

going back to operating components is not considered to contribute to the thermal value of the 

process streams. For example, the burner auxiliaries such as blowers may heat the process 

stream, but this effect is minimal and was not modeled. Therefore, auxiliary energy is counted as 

an output of the system, which is internally consumed. Note that, because the model uses 1-hour 

time steps, power values of kW have equivalent numeric value as the energy flow of kWh for 

each time step.
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at www.nrel.gov/publications.

Figure 44. FCPower Model hourly energy model, for fuel cell energy balance example
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National Renewable Energy Laboratory (NREL) 

at www.nrel.gov/publications.

Figure 45. FCPower Model hourly energy model, for fuel cell system energy balance example
This report is available at no cost from the 49 

National Renewable Energy Laboratory (NREL) 

at www.nrel.gov/publications.

2.6 ASPEN System Process Flow Diagrams and Energy/Material Stream Tables

This section shows the process flow diagrams and energy/material stream tables for the fuel cell systems modeled in ASPEN Plus. 

Each diagram is followed by tables with columns corresponding to the labels on the diagram. The diagram labels are very small; to 

read them, use the zoom function on your computer. 

Figure 46. MCFC ASPEN process flow diagram

522

0.10

CAT-IN

522

FLUX-OUT 0.02

522

0.08

CAT-INT

650

0.01

FUEL-HOT

522

FLUX-IN 0.02

NRG-TOT 2.101

650

0.03

ANODEOUT

650

AN-OUT-8 0.00

30

0.07

AIR3

650

BYPASS 0.03

266

0.10

BURN-IN

18

0.01

FUEL-MIX

650

CAT-OUT2 0.08

459

CAT-OUT3 0.08

30

0.00

FUEL-2

20

0.01

WATER-2

20

0.01

WATER

20

0.00

FUEL

42

0.00

FUEL-1

20

0.07

AIR

41

0.07

AIR-1

1.735

DC-POWER

1.399

AC-POWER

Q

0.121

INV-LOSS

0.215 Q

AUX-POW

Q

AN-HEAT 0.367

515

0.08

CAT-OUT1

0.963

HEAT

Q

75

CAT-OUT4 0.08

263

0.00

AN-OUT-2

-263

0.00

AN-OUT-3

HL-SHIFT 0.001

Q

-263

0.00

S1

30

0.00

AN-OUT-4

30

COND-02 0.00

HL-CHR1 0.000

Q

30

0.00

AN-OUT-6

30

0.00

AN-OUT-7

30

0.00

H2-LP

25

0.00

AN-OUT-5

30

COND-03 0.00

-0.000 HL-CHLR2

Q

650

0.00

AN-OUT-1

30

0.07

AIR-2

HL-FUEL 0.002

Q

HL-AIR 0.021

Q

25

0.00

H2-HP

0.020

HL-FC

Q

75

EXHAUST 0.08

0.00

COND

CATHODE

ANODE

MIX-2

BURNER

HX-AN MIX-1

PMP-H2O

CMP-FUEL

CMP-AIR

Q

POW-CONV

CAT-HXFR

Q

B18

TRM-LOAD

SHIFT

REF-CLR1

PSA

REF-CLR2

FHLOSS RECOUP AIR-HTR

AHLOSS

CMP3-HP

PSACMPR

HL-FC

BYPASS

FLASH Temperature (C)

Molar Flow Rate (kmol/sec)

Duty (MW)
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Table 1. MCFC-CHP Stream Table

AIR AIR-1 AIR-2 AIR3 AN-OUT-1 AN-OUT-2 AN-OUT-3 AN-OUT-4 AN-OUT-5 AN-OUT-6 AN-OUT-7 AN-OUT-8

Mole Flow kmol/sec

CO2 0 0 0 0 1.46E-06 1.46E-06 1.59E-06 1.59E-06 1.59E-06 1.59E-06 1.59E-06 1.59E-06

CO 0 0 0 0 1.28E-07 1.28E-07 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0 0

CH4 0 0 0 0 4.94E-11 4.94E-11 4.94E-11 4.94E-11 4.94E-11 4.94E-11 4.94E-11 4.94E-11

H2 0 0 0 0 2.04E-07 2.04E-07 3.32E-07 3.32E-07 3.32E-07 3.32E-07 1.16E-07 1.16E-07

O2 0.0145313 0.0145313 0.0145313 0.0145313 4.34E-27 4.34E-27 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0 0

N2 0.0546655 0.0546655 0.0546655 0.0546655 0 0 0 0 0 0 0 0

H2O 0 0 0 0 1.14E-06 1.14E-06 1.01E-06 1.04E-09 1.04E-09 1.14E-10 1.14E-10 1.14E-10

Mole Frac

CO2 0 0 0 0 0.4980502 0.4980502 0.5415985 0.8266444 0.8266444 0.8270434 0.9317396 0.9317396

CO 0 0 0 0 0.0435482 0.0435482 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0 0

CH4 0 0 0 0 1.69E-05 1.69E-05 1.69E-05 2.57E-05 2.57E-05 2.58E-05 2.90E-05 2.90E-05

H2 0 0 0 0 0.0696584 0.0696584 0.1132067 0.1727879 0.1727879 0.1728713 0.0681643 0.0681643

O2 0.21 0.21 0.21 0.21 1.48E-21 1.48E-21 0.00E+00 0.00E+00 0.00E+00 0.00E+00 0 0

N2 0.79 0.79 0.79 0.79 0 0 0 0 0 0 0 0

H2O 0 0 0 0 0.3887262 0.3887262 0.3451779 5.42E-04 5.42E-04 5.95E-05 6.70E-05 6.70E-05

Total Flow kg/sec 1.996358 1.996358 1.996358 1.996358 8.87E-05 8.87E-05 8.87E-05 7.05E-05 7.05E-05 7.05E-05 7.01E-05 7.01E-05

Temperature C 20 40.55239 30 30 650 262.579 -263.15 30 25 30 30 650

Pressure psia 14.7 16.2 16.2 16.2 16.2 16.2 16.2 16.2 164.7 164.7 164.7 164.7

Vapor Frac 1 1 1 1 1 1 1 1 1 1 1 1

Enthalpy J/kmol -1.53E+05 4.47E+05 1.39E+05 1.39E+05 -2.69E+08 -2.86E+08 -3.06E+08 -3.25E+08 -3.26E+08 -3.26E+08 -3.67E+08 -3.38E+08

Enthalpy J/kg -5299.787 15498.39 4805.04 4805.04 -8.89E+06 -9.44E+06 -1.01E+07 -8.85E+06 -8.87E+06 -8.86E+06 -8.92E+06 -8.22E+06

Enthalpy MW -0.0105802 0.0309403 9.59E-03 9.59E-03 -7.89E-04 -8.38E-04 -8.96E-04 -6.24E-04 -6.25E-04 -6.25E-04 -6.25E-04 -5.76E-04

Entropy J/kmol-K 3757.812 4928.597 3928.237 3928.237 40994.46 17768.04 2.76E+06 5952.465 -14517.9 -13901.25 -15490.56 34611.99

Entropy J/kg-K 130.2517 170.8329 136.1589 136.1589 1353.73 586.741 91138.08 162.0206 -395.1638 -378.2859 -376.4892 841.2247

Density kmol/cum 0.0416047 0.04284 0.0443354 0.0443354 0.0145542 0.0251086 0.0239404 0.0444716 0.4763239 0.4675054 0.4727921 0.14785

Density kg/cum 1.200312 1.235953 1.279095 1.279095 0.4407393 0.7603552 0.7249797 1.633842 17.49964 17.17988 19.45292 6.083252

Average MW 28.8504 28.8504 28.8504 28.8504 30.2826 30.2826 30.2826 36.73895 36.73895 36.74799 41.14476 41.14476

*** ALL PHASES ***

TDEW C -191.0213 -190.1785 -190.1785 -190.1785 77.97679 77.97679 75.12089 30 3.248492 30 -18.57765 -18.57765
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Table 1 (cont.)

ANODEOUT BURN-IN BYPASS CAT-IN CAT-INT CAT-OUT1 CAT-OUT2 CAT-OUT3 CAT-OUT4 COND COND-02 COND-03

Mole Flow kmol/sec

CO2 0.0145943 0.0145944 0.0145928 0.0158709 3.84E-03 3.84E-03 3.84E-03 3.84E-03 3.84E-03 0 0 0

CO 1.28E-03 1.28E-03 1.28E-03 0 0 0 0 0 0 0 0 0

CH4 4.94E-07 4.94E-07 4.94E-07 0 0 0 0 0 0 0 0 0

H2 2.04E-03 2.04E-03 2.04E-03 0 0 0 0 0 0 0 0 0

O2 4.34E-23 0.0145313 4.34E-23 0.0128718 6.86E-03 6.86E-03 6.86E-03 6.86E-03 6.86E-03 0 0 0

N2 0 0.0546655 0 0.0546655 0.0546655 0.0546655 0.0546655 0.0546655 0.0546655 0 0 0

H2O 0.0113908 0.0113897 0.0113897 0.0134317 0.0134317 0.0134317 0.0134317 0.0134317 0.0134317 0 1.01E-06 9.26E-10

Mole Frac

CO2 0.4980502 0.1481693 0.4980502 0.1638881 0.0487113 0.0487113 0.0487113 0.0487113 0.0487113 0 0 0

CO 0.0435482 0.0129541 0.0435482 0 0 0 0 0 0 0 0 0

CH4 1.69E-05 5.02E-06 1.69E-05 0 0 0 0 0 0 0 0 0

H2 0.0696584 0.0207222 0.0696584 0 0 0 0 0 0 0 0 0

O2 1.48E-21 0.1475284 1.48E-21 0.1329183 0.0870082 0.0870082 0.0870082 0.0870082 0.0870082 0 0 0

N2 0 0.5549879 0 0.5644929 0.6938063 0.6938063 0.6938063 0.6938063 0.6938063 0 0 0

H2O 0.3887262 0.115633 0.3887262 0.1387007 0.1704741 0.1704741 0.1704741 0.1704741 0.1704741 0 1 1

Total Flow kg/sec 0.8873703 2.88371 0.8872815 2.88371 2.161626 2.161626 2.161626 2.161626 2.161626 0 1.82E-05 1.67E-08

Temperature C 650 266.066 650 522.1475 522.1475 514.6315 650.3007 459.4951 75 30 30

Pressure psia 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 164.7

Vapor Frac 1 1 1 1 1 1 1 1 1 0 0

Enthalpy J/kmol -2.69E+08 -8.00E+07 -2.69E+08 -8.14E+07 -4.46E+07 -4.48E+07 -4.02E+07 -4.67E+07 -5.89E+07 -2.85E+08 -2.85E+08

Enthalpy J/kg -8.89E+06 -2.73E+06 -8.89E+06 -2.73E+06 -1.62E+06 -1.63E+06 -1.46E+06 -1.70E+06 -2.15E+06 -1.58E+07 -1.58E+07

Enthalpy MW -7.889775 -7.879969 -7.888986 -7.879969 -3.510625 -3.530625 -3.164077 -3.676214 -4.639528 -2.88E-04 -2.64E-07

Entropy J/kmol-K 40994.46 25136.3 40994.46 35664.4 30348.64 30027.95 35474.32 27596.46 4062.048 -1.62E+05 -1.62E+05

Entropy J/kg-K 1353.73 858.5786 1353.73 1197.674 1106.201 1094.512 1293.031 1005.885 148.0608 -8986.351 -8986.878

Density kmol/cum 0.0145542 0.0249158 0.0145542 0.0168895 0.0168892 0.0170504 0.014545 0.018334 0.0386331 55.27336 55.29857

Density kg/cum 0.4407393 0.7294514 0.4407393 0.5029376 0.4633562 0.4677781 0.3990428 0.5029933 1.0599 995.7651 996.2192

Average MW 30.2826 29.27664 30.2826 29.77805 27.435 27.435 27.435 27.435 27.435 18.01528 18.01528

*** ALL PHASES ***

TDEW C 77.97679 50.8618 77.97679 54.60628 58.92372 58.92372 58.92372 58.92372 58.92372 102.7428 185.4826
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Table 1 (cont.)

EXHAUST FLUX-IN FLUX-OUT FUEL FUEL-1 FUEL-2 FUEL-HOT FUEL-MIX H2-HP H2-LP S1 WATER WATER-2

Mole Flow kmol/sec

CO2 3.84E-03 0.0120329 0.0120329 0 0 0 0 0 0 0 1.59E-06 0 0

CO 0 0 0 0 0 0 0 0 0 0 0.00E+00 0 0

CH4 0 0 0 3.84E-03 3.84E-03 3.84E-03 3.84E-03 3.84E-03 0 0 4.94E-11 0 0

H2 0 0 0 0 0 0 0 0 2.16E-07 2.16E-07 3.32E-07 0 0

O2 6.86E-03 6.02E-03 6.02E-03 0 0 0 0 0 0 0 0.00E+00 0 0

N2 0.0546655 0 0 0 0 0 0 0 0 0 0 0 0

H2O 0.0134317 0 0 0 0 0 5.76E-03 5.76E-03 0 0 1.01E-06 5.76E-03 5.76E-03

Mole Frac

CO2 0.0487113 0.66667 0.66667 0 0 0 0 0 0 0 0.5415985 0 0

CO 0 0 0 0 0 0 0 0 0 0 0.00E+00 0 0

CH4 0 0 0 1 1 1 0.4 0.4 0 0 1.69E-05 0 0

H2 0 0 0 0 0 0 0 0 1 1 0.1132067 0 0

O2 0.0870082 0.33333 0.33333 0 0 0 0 0 0 0 0.00E+00 0 0

N2 0.6938063 0 0 0 0 0 0 0 0 0 0 0 0

H2O 0.1704741 0 0 0 0 0 0.6 0.6 0 0 0.3451779 1 1

Total Flow kg/sec 2.161626 0.7220839 0.7220839 0.0615722 0.0615722 0.0615722 0.1652863 0.1652863 4.35E-07 4.35E-07 8.87E-05 0.1037141 0.1037141

Temperature C 75 522.1475 522.1475 20 41.92543 30 650.3005 18.46574 25 30 -263.15 20 20.21997

Pressure psia 16.2 16.2 16.2 14.7 16.7 16.7 16.7 16.7 6250 164.7 16.2 14.7 64.7

Vapor Frac 1 1 1 1 1 1 1 0.3956657 1 1 1 0 0

Enthalpy J/kmol -5.89E+07 -2.42E+08 -2.42E+08 -7.47E+07 -7.39E+07 -7.44E+07 -1.48E+08 -2.01E+08 5.68E+05 1.56E+05 -3.06E+08 -2.86E+08 -2.86E+08

Enthalpy J/kg -2.15E+06 -6.05E+06 -6.05E+06 -4.66E+06 -4.61E+06 -4.64E+06 -8.59E+06 -1.17E+07 2.82E+05 77156.4 -1.01E+07 -1.59E+07 -1.59E+07

Enthalpy MW -4.639528 -4.369348 -4.369348 -0.2867546 -0.2837325 -0.2853897 -1.419769 -1.931943 1.22E-07 3.35E-08 -8.96E-04 -1.646672 -1.646553

Entropy J/kmol-K 4062.048 45556.72 45556.72 -81241.23 -79709.86 -81106.81 -7527.105 -1.31E+05 -50721.69 -19631.15 2.76E+06 -1.64E+05 -1.64E+05

Entropy J/kg-K 148.0608 1138.742 1138.742 -5064.043 -4968.588 -5055.665 -436.955 -7577.787 -25161.06 -9738.254 91138.08 -9094.916 -9092.205

Density kmol/cum 0.0386331 0.016891 0.016891 0.0416652 0.0440297 0.0457735 0.0149997 0.120156 13.48305 0.4475042 0.0239404 55.44 55.42829

Density kg/cum 1.0599 0.6757468 0.6757468 0.6684259 0.7063578 0.7343338 0.258389 2.06984 27.18021 0.9021147 0.7249797 998.7672 998.5561

Average MW 27.435 40.00617 40.00617 16.04276 16.04276 16.04276 17.22627 17.22627 2.01588 2.01588 30.2826 18.01528 18.01528

*** ALL PHASES ***

TDEW C 58.92372 -93.4242 -93.4242 -161.4806 -159.9087 -159.9087 89.60892 89.60892 -240.9779 75.12089 100.0252 147.6647
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Table 2. MCFC-CHHP Stream Table

AIR AIR-1 AIR-2 AIR3 AN-OUT-1 AN-OUT-2 AN-OUT-3 AN-OUT-4 AN-OUT-5 AN-OUT-6 AN-OUT-7 AN-OUT-8

Mole Flow kmol/sec

CO2 0 0 0 0 0.0145928 0.0145928 0.0157243 0.0157243 0.0157243 0.0157243 0.0157243 0.0157243

CO 0 0 0 0 1.28E-03 1.28E-03 1.45E-04 1.45E-04 1.45E-04 1.45E-04 1.45E-04 1.45E-04

CH4 0 0 0 0 4.94E-07 4.94E-07 4.94E-07 4.94E-07 4.94E-07 4.94E-07 4.94E-07 4.94E-07

H2 0 0 0 0 2.04E-03 2.04E-03 3.17E-03 3.17E-03 3.17E-03 3.17E-03 8.72E-04 8.72E-04

O2 0.0107645 0.0107645 0.0107645 0.0107645 4.34E-23 4.34E-23 0 0 0 0 0 0

N2 0.0404952 0.0404952 0.0404952 0.0404952 0 0 0 0 0 0 0 0

H2O 0 0 0 0 0.0113897 0.0113897 0.0102582 1.03E-05 1.03E-05 1.13E-06 1.13E-06 1.13E-06

Mole Frac

CO2 0 0 0 0 0.4980502 0.4980502 0.5366653 0.8253326 0.8253326 0.825731 0.9391632 0.9391632

CO 0 0 0 0 0.0435482 0.0435482 4.93E-03 7.59E-03 7.59E-03 7.59E-03 8.63E-03 8.63E-03

CH4 0 0 0 0 1.69E-05 1.69E-05 1.69E-05 2.59E-05 2.59E-05 2.60E-05 2.95E-05 2.95E-05

H2 0 0 0 0 0.0696584 0.0696584 0.1082735 0.1665128 0.1665128 0.1665932 0.0521065 0.0521065

O2 0.21 0.21 0.21 0.21 1.48E-21 1.48E-21 0 0 0 0 0 0

N2 0.79 0.79 0.79 0.79 0 0 0 0 0 0 0 0

H2O 0 0 0 0 0.3887262 0.3887262 0.3501111 5.42E-04 5.42E-04 5.95E-05 6.77E-05 6.77E-05

Total Flow kg/sec 1.478866 1.478866 1.478866 1.478866 0.8872815 0.8872815 0.8872815 0.7026619 0.7026619 0.7024963 0.6978598 0.6978598

Temperature C 20 40.55239 30 214.5115 650 276.8076 313.9461 30 25 30 30 638.4248

Pressure psia 14.7 16.2 16.2 16.2 16.2 16.2 16.2 16.2 164.7 164.7 164.7 164.7

Vapor Frac 1 1 1 1 1 1 1 1 1 1 1 1

Enthalpy J/kmol -1.53E+05 4.47E+05 1.39E+05 5.58E+06 -2.69E+08 -2.85E+08 -2.85E+08 -3.26E+08 -3.26E+08 -3.26E+08 -3.71E+08 -3.43E+08

Enthalpy J/kg -5299.787 15498.39 4805.04 1.93E+05 -8.89E+06 -9.42E+06 -9.42E+06 -8.83E+06 -8.84E+06 -8.83E+06 -8.89E+06 -8.22E+06

Enthalpy MW -7.84E-03 0.02292 7.11E-03 0.2858254 -7.888986 -8.359316 -8.359644 -6.203283 -6.211701 -6.205893 -6.206882 -5.736178

Entropy J/kmol-K 3757.812 4928.597 3928.237 17926.31 40994.46 18819.19 19468.33 6902.016 -13570.67 -12953.57 -14672.78 34935.33

Entropy J/kg-K 130.2517 170.8329 136.1589 621.354 1353.73 621.4522 642.8882 187.1425 -367.9575 -351.1388 -352.0262 838.1608

Density kmol/cum 0.0416047 0.04284 0.0443354 0.0275418 0.0145542 0.0244564 0.0229019 0.0444723 0.4764139 0.4675893 0.4733929 0.1497441

Density kg/cum 1.200312 1.235953 1.279095 0.7945924 0.4407393 0.7406045 0.6935311 1.64019 17.57066 17.24945 19.73146 6.241475

Average MW 28.8504 28.8504 28.8504 28.8504 30.2826 30.2826 30.2826 36.88108 36.88108 36.89018 41.68093 41.68093

*** ALL PHASES ***

TDEW C -191.0213 -190.1785 -190.1785 -190.1785 77.97679 77.97679 75.45921 30 3.2435 30 -18.39963 -18.39963
This report is available at no cost from the 54 

National Renewable Energy Laboratory (NREL) 

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Table 2 (cont.)

ANODEOUT BURN-IN BYPASS CAT-IN CAT-INT CAT-OUT1 CAT-OUT2 CAT-OUT3 CAT-OUT4 COND COND-02 COND-03

Mole Flow kmol/sec

CO2 0.0145943 0.0157257 1.46E-06 0.0158709 3.84E-03 3.84E-03 3.84E-03 3.84E-03 3.84E-03 0 0 0

CO 1.28E-03 1.45E-04 1.28E-07 0 0 0 0 0 0 0 0 0

CH4 4.94E-07 4.94E-07 4.94E-11 0 0 0 0 0 0 0 0 0

H2 2.04E-03 8.73E-04 2.04E-07 0 0 0 0 0 0 0 0 0

O2 4.34E-23 0.0107645 4.34E-27 0.0102549 4.24E-03 4.24E-03 4.24E-03 4.24E-03 4.24E-03 0 0 0

N2 0 0.0404952 0 0.0404952 0.0404952 0.0404952 0.0404952 0.0404952 0.0404952 0 0 0

H2O 0.0113908 2.27E-06 1.14E-06 8.76E-04 8.76E-04 8.76E-04 8.76E-04 8.76E-04 8.76E-04 0 0.0102479 9.19E-06

Mole Frac

CO2 0.4980502 0.2312422 0.4980502 0.2351355 0.0776174 0.0776174 0.0776174 0.0776174 0.0776174 0 0 0

CO 0.0435482 2.13E-03 0.0435482 0 0 0 0 0 0 0 0 0

CH4 1.69E-05 7.27E-06 1.69E-05 0 0 0 0 0 0 0 0 0

H2 0.0696584 0.0128315 0.0696584 0 0 0 0 0 0 0 0 0

O2 1.48E-21 0.1582892 1.48E-21 0.1519316 0.0857178 0.0857178 0.0857178 0.0857178 0.0857178 0 0 0

N2 0 0.595469 0 0.5999564 0.8189514 0.8189514 0.8189514 0.8189514 0.8189514 0 0 0

H2O 0.3887262 3.34E-05 0.3887262 0.0129765 0.0177132 0.0177132 0.0177132 0.0177132 0.0177132 0 1 1

Total Flow kg/sec 0.8873703 2.176815 8.87E-05 2.176815 1.454731 1.454731 1.454731 1.454731 1.454731 0 0.1846196 1.66E-04

Temperature C 650 361.5354 650 468.3004 468.3004 455.9646 650.2271 336.5957 75 30 30

Pressure psia 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 164.7

Vapor Frac 1 1 1 1 1 1 1 1 1 0 0

Enthalpy J/kmol -2.69E+08 -8.02E+07 -2.69E+08 -8.08E+07 -2.10E+07 -2.14E+07 -1.49E+07 -2.53E+07 -3.33E+07 -2.85E+08 -2.85E+08

Enthalpy J/kg -8.89E+06 -2.50E+06 -8.89E+06 -2.50E+06 -7.14E+05 -7.27E+05 -5.06E+05 -8.58E+05 -1.13E+06 -1.58E+07 -1.58E+07

Enthalpy MW -7.889775 -5.451142 -7.89E-04 -5.451142 -1.038153 -1.058153 -0.7365072 -1.248607 -1.648332 -2.925242 -2.62E-03

Entropy J/kmol-K 40994.46 33138.7 40994.46 37822.32 32203.49 31653.39 39555.85 25886.98 8612.065 -1.62E+05 -1.62E+05

Entropy J/kg-K 1353.73 1035.283 1353.73 1172.766 1094.628 1075.929 1344.541 879.9234 292.7324 -8986.351 -8986.878

Density kmol/cum 0.0145542 0.0211626 0.0145542 0.0181148 0.0181137 0.0184202 0.0145449 0.0220269 0.0386013 55.27336 55.29857

Density kg/cum 0.4407393 0.6774008 0.4407393 0.5842127 0.5328985 0.541915 0.4279075 0.6480233 1.135636 995.7651 996.2192

Average MW 30.2826 32.00932 30.2826 32.25054 29.41959 29.41959 29.41959 29.41959 29.41959 18.01528 18.01528

*** ALL PHASES ***

TDEW C 77.97679 -55.32611 77.97679 12.51084 17.26529 17.26529 17.26529 17.26529 17.26529 102.7428 185.4826
This report is available at no cost from the 55 

National Renewable Energy Laboratory (NREL) 

at www.nrel.gov/publications.

Table 2 (cont.)

EXHAUST FLUX-IN FLUX-OUT FUEL FUEL-1 FUEL-2 FUEL-HOT FUEL-MIX H2-HP H2-LP S1 WATER WATER-2

Mole Flow kmol/sec

CO2 3.84E-03 0.0120329 0.0120329 0 0 0 0 0 0 0 0.0157243 0 0

CO 0 0 0 0 0 0 0 0 0 0 1.45E-04 0 0

CH4 0 0 0 3.84E-03 3.84E-03 3.84E-03 3.84E-03 3.84E-03 0 0 4.94E-07 0 0

H2 0 0 0 0 0 0 0 0 2.30E-03 2.30E-03 3.17E-03 0 0

O2 4.24E-03 6.02E-03 6.02E-03 0 0 0 0 0 0 0 0 0 0

N2 0.0404952 0 0 0 0 0 0 0 0 0 0 0 0

H2O 8.76E-04 0 0 0 0 0 5.76E-03 5.76E-03 0 0 0.0102582 5.76E-03 5.76E-03

Mole Frac

CO2 0.0776174 0.66667 0.66667 0 0 0 0 0 0 0 0.5366653 0 0

CO 0 0 0 0 0 0 0 0 0 0 4.93E-03 0 0

CH4 0 0 0 1 1 1 0.4 0.4 0 0 1.69E-05 0 0

H2 0 0 0 0 0 0 0 0 1 1 0.1082735 0 0

O2 0.0857178 0.33333 0.33333 0 0 0 0 0 0 0 0 0 0

N2 0.8189514 0 0 0 0 0 0 0 0 0 0 0 0

H2O 0.0177132 0 0 0 0 0 0.6 0.6 0 0 0.3501111 1 1

Total Flow kg/sec 1.454731 0.7220839 0.7220839 0.0615722 0.0615722 0.0615722 0.1652863 0.1652863 4.64E-03 4.64E-03 0.8872815 0.1037141 0.1037141

Temperature C 74.99993 468.3004 468.3004 20 41.92543 30 650.2265 18.46574 25 30 75.25558 20 20.21997

Pressure psia 16.2 16.2 16.2 14.7 16.7 16.7 16.7 16.7 6250 164.7 16.2 14.7 64.7

Vapor Frac 1 1 1 1 1 1 1 0.3956657 1 1 0.9953691 0 0

Enthalpy J/kmol -3.33E+07 -2.45E+08 -2.45E+08 -7.47E+07 -7.39E+07 -7.44E+07 -1.48E+08 -2.01E+08 5.68E+05 1.56E+05 -2.95E+08 -2.86E+08 -2.86E+08

Enthalpy J/kg -1.13E+06 -6.11E+06 -6.11E+06 -4.66E+06 -4.61E+06 -4.64E+06 -8.59E+06 -1.17E+07 2.82E+05 77156.4 -9.74E+06 -1.59E+07 -1.59E+07

Enthalpy MW -1.648332 -4.413001 -4.413001 -0.2867546 -0.2837325 -0.2853897 -1.419933 -1.931943 1.31E-03 3.58E-04 -8.638364 -1.646672 -1.646553

Entropy J/kmol-K 8612.059 42408.14 42408.14 -81241.23 -79709.86 -81106.81 -7531.268 -1.31E+05 -50721.69 -19631.15 -1355.441 -1.64E+05 -1.64E+05

Entropy J/kg-K 292.7322 1060.04 1060.04 -5064.043 -4968.588 -5055.665 -437.1966 -7577.787 -25161.06 -9738.254 -44.75974 -9094.916 -9092.205

Density kmol/cum 0.0386013 0.0181185 0.0181185 0.0416652 0.0440297 0.0457735 0.0150009 0.120156 13.48305 0.4475042 0.0389068 55.44 55.42829

Density kg/cum 1.135636 0.7248553 0.7248553 0.6684259 0.7063578 0.7343338 0.2584097 2.06984 27.18021 0.9021147 1.178201 998.7672 998.5561

Average MW 29.41959 40.00617 40.00617 16.04276 16.04276 16.04276 17.22627 17.22627 2.01588 2.01588 30.2826 18.01528 18.01528

*** ALL PHASES ***

TDEW C 17.26529 -93.4242 -93.4242 -161.4806 -159.9087 -159.9087 89.60892 89.60892 -240.9779 75.45921 100.0252 147.6647
This report is available at no cost from the 56 

National Renewable Energy Laboratory (NREL) 

at www.nrel.gov/publications.

Table 3. MCFC-CHHP with Hydrogen Over-Production Stream Table

AIR AIR-1 AIR-2 AIR3 AN-OUT-1 AN-OUT-2 AN-OUT-3 AN-OUT-4 AN-OUT-5 AN-OUT-6 AN-OUT-7 AN-OUT-8

Mole Flow kmol/sec 

CO2 0 0 0 0 0.0139835 0.0139835 0.0156367 0.0156367 0.0156367 0.0156367 0.0156367 0.0156367

CO 0 0 0 0 1.95E-03 1.95E-03 2.94E-04 2.94E-04 2.94E-04 2.94E-04 2.94E-04 2.94E-04

CH4 0 0 0 0 2.83E-06 2.83E-06 2.83E-06 2.83E-06 2.83E-06 2.83E-06 2.83E-06 2.83E-06

H2 0 0 0 0 3.29E-03 3.29E-03 4.94E-03 4.94E-03 4.94E-03 4.94E-03 1.31E-03 1.31E-03

O2 0.0111705 0.0111705 0.0111705 0.0111705 1.80E-23 1.80E-23 2.52E-14 2.52E-14 2.52E-14 2.52E-14 2.52E-14 2.52E-14

N2 0.0420226 0.0420226 0.0420226 0.0420226 0 0 0 0 0 0 0 0

H2O 0 0 0 0 0.0115311 0.0115311 9.88E-03 1.13E-05 1.13E-05 1.23E-06 1.23E-06 1.23E-06

Mole Frac 

CO2 0 0 0 0 0.4546778 0.4546778 0.5084341 0.7485933 0.7485933 0.7489547 0.9067662 0.9067662

CO 0 0 0 0 0.0633041 0.0633041 9.55E-03 0.0140577 0.0140577 0.0140645 0.0170281 0.0170281

CH4 0 0 0 0 9.21E-05 9.21E-05 9.21E-05 1.36E-04 1.36E-04 1.36E-04 1.64E-04 1.64E-04

H2 0 0 0 0 0.1069878 0.1069878 0.1607441 0.2366717 0.2366717 0.2367859 0.0759698 0.0759698

O2 0.21 0.21 0.21 0.21 5.85E-22 5.85E-22 8.18E-13 1.20E-12 1.20E-12 1.21E-12 1.46E-12 1.46E-12

N2 0.79 0.79 0.79 0.79 0 0 0 0 0 0 0 0

H2O 0 0 0 0 0.3749381 0.3749381 0.3211818 5.42E-04 5.42E-04 5.91E-05 7.16E-05 7.16E-05

Total Flow kg/sec 1.534644 1.534644 1.534644 1.534644 0.8843597 0.8843597 0.8843597 0.706611 0.706611 0.7064294 0.6991046 0.6991046

Temperature C 20 40.55239 30 224.3202 650 280.5265 331.6598 30 25 30 30 638.1663

Pressure psia 14.7 16.2 16.2 16.2 16.2 16.2 16.2 16.2 164.7 164.7 164.7 164.7

Vapor Frac 1 1 1 1 1 1 1 1 1 1 1 1

Enthalpy J/kmol -1.53E+05 4.47E+05 1.39E+05 5.87E+06 -2.52E+08 -2.67E+08 -2.67E+08 -2.96E+08 -2.97E+08 -2.96E+08 -3.59E+08 -3.31E+08

Enthalpy J/kg -5299.787 15498.39 4805.04 2.03E+05 -8.75E+06 -9.29E+06 -9.29E+06 -8.75E+06 -8.77E+06 -8.76E+06 -8.85E+06 -8.17E+06

Enthalpy MW -8.13E-03 0.0237845 7.37E-03 0.3121905 -7.736414 -8.215334 -8.216334 -6.185425 -6.193703 -6.187432 -6.188863 -5.710338

Entropy J/kmol-K 3757.812 4928.597 3928.237 18521.14 43240.31 21822.43 22591.51 8284.26 -12088.16 -11485.76 -13148.35 35844.46

Entropy J/kg-K 130.2517 170.8329 136.1589 641.9717 1503.738 758.903 785.649 244.8918 -357.3394 -339.4552 -324.3251 884.1614

Density kmol/cum 0.0416047 0.04284 0.0443354 0.0269985 0.0145536 0.024288 0.0222261 0.0444437 0.4728927 0.464296 0.471832 0.1497646

Density kg/cum 1.200312 1.235953 1.279095 0.7789177 0.4184941 0.698409 0.6391186 1.503453 15.99713 15.70986 19.12837 6.07155

Average MW 28.8504 28.8504 28.8504 28.8504 28.75522 28.75522 28.75522 33.82824 33.82824 33.83587 40.54063 40.54063

*** ALL PHASES *** 

TDEW C -191.0213 -190.1785 -190.1785 -190.1785 77.07923 77.07923 73.3909 30 2.816143 30 -18.24226 -18.24226
This report is available at no cost from the 57 

National Renewable Energy Laboratory (NREL) 

at www.nrel.gov/publications.

Table 3 (cont.)

ANODEOUT BURN-IN BYPASS CAT-IN CAT-INT CAT-OUT1 CAT-OUT2 CAT-OUT3 CAT-OUT4 COND COND-02 COND-03

Mole Flow kmol/sec 

CO2 0.0139849 0.0156381 1.40E-06 0.0159348 4.24E-03 4.24E-03 4.24E-03 4.24E-03 4.24E-03 0 0 0

CO 1.95E-03 2.94E-04 1.95E-07 0 0 0 0 0 0 0 0 0

CH4 2.83E-06 2.83E-06 2.83E-10 0 0 0 0 0 0 0 0 0

H2 3.29E-03 1.31E-03 3.29E-07 0 0 0 0 0 0 0 0 0

O2 1.80E-23 0.0111705 1.80E-27 0.0103627 4.51E-03 4.51E-03 4.51E-03 4.51E-03 4.51E-03 0 0 0

N2 0 0.0420226 0 0.0420226 0.0420226 0.0420226 0.0420226 0.0420226 0.0420226 0 0 0

H2O 0.0115322 2.39E-06 1.15E-06 1.32E-03 1.32E-03 1.32E-03 1.32E-03 1.32E-03 1.32E-03 0 9.87E-03 1.01E-05

Mole Frac 

CO2 0.4546778 0.2220044 0.4546778 0.2288216 0.0813328 0.0813328 0.0813328 0.0813328 0.0813328 0 0 0

CO 0.0633041 4.17E-03 0.0633041 0 0 0 0 0 0 0 0 0

CH4 9.21E-05 4.02E-05 9.21E-05 0 0 0 0 0 0 0 0 0

H2 0.1069878 0.0186027 0.1069878 0 0 0 0 0 0 0 0 0

O2 5.85E-22 0.1585809 5.85E-22 0.1488079 0.0866518 0.0866518 0.0866518 0.0866518 0.0866518 0 0 0

N2 0 0.5965664 0 0.6034378 0.8067052 0.8067052 0.8067052 0.8067052 0.8067052 0 0 0

H2O 0.3749381 3.39E-05 0.3749381 0.0189327 0.0253101 0.0253101 0.0253101 0.0253101 0.0253101 0 1 1

Total Flow kg/sec 0.8844482 2.233837 8.84E-05 2.233837 1.531848 1.531848 1.531848 1.531848 1.531848 0 0.1777487 1.82E-04

Temperature C 650 365.8406 650 529.6255 529.6255 518.1307 649.7005 321.9014 75 30 30

Pressure psia 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 164.7

Vapor Frac 1 1 1 1 1 1 1 1 1 0 0

Enthalpy J/kmol -2.52E+08 -7.66E+07 -2.52E+08 -7.75E+07 -2.22E+07 -2.26E+07 -1.81E+07 -2.90E+07 -3.66E+07 -2.85E+08 -2.85E+08

Enthalpy J/kg -8.75E+06 -2.42E+06 -8.75E+06 -2.42E+06 -7.55E+05 -7.68E+05 -6.17E+05 -9.86E+05 -1.25E+06 -1.58E+07 -1.58E+07

Enthalpy MW -7.737188 -5.398921 -7.74E-04 -5.398921 -1.157128 -1.177128 -0.9451046 -1.510119 -1.908158 -2.816374 -2.88E-03

Entropy J/kmol-K 43240.31 33628.7 43240.31 40452.9 34921.84 34440.12 39645.39 25166.31 8614.979 -1.62E+05 -1.62E+05

Entropy J/kg-K 1503.738 1060.432 1503.738 1261.097 1187.544 1171.162 1348.172 855.7995 292.9589 -8986.351 -8986.878

Density kmol/cum 0.0145536 0.0210198 0.0145536 0.0167308 0.01673 0.0169731 0.0145533 0.0225713 0.0386033 55.27336 55.29857

Density kg/cum 0.4184941 0.6665866 0.4184941 0.5366842 0.4919781 0.4991251 0.4279674 0.6637505 1.135199 995.7651 996.2192

Average MW 28.75522 31.71227 28.75522 32.07754 29.40678 29.40678 29.40678 29.40678 29.40678 18.01528 18.01528

*** ALL PHASES *** 

TDEW C 77.07923 -55.21833 77.07923 18.37931 23.02893 23.02893 23.02893 23.02893 23.02893 102.7428 185.4826
This report is available at no cost from the 58 

National Renewable Energy Laboratory (NREL) 

at www.nrel.gov/publications.

Table 3 (cont.)

EXHAUST FLUX-IN FLUX-OUT FUEL FUEL-1 FUEL-2 FUEL-HOT FUEL-MIX H2-HP H2-LP S1 WATER WATER-2

Mole Flow kmol/sec 

CO2 4.24E-03 0.011698 0.011698 0 0 0 0 0 0 0 0.0156367 0 0

CO 0 0 0 0 0 0 0 0 0 0 2.94E-04 0 0

CH4 0 0 0 4.24E-03 4.24E-03 4.24E-03 4.24E-03 4.24E-03 0 0 2.83E-06 0 0

H2 0 0 0 0 0 0 0 0 3.63E-03 3.63E-03 4.94E-03 0 0

O2 4.51E-03 5.85E-03 5.85E-03 0 0 0 0 0 0 0 2.52E-14 0 0

N2 0.0420226 0 0 0 0 0 0 0 0 0 0 0 0

H2O 1.32E-03 0 0 0 0 0 6.36E-03 6.36E-03 0 0 9.88E-03 6.36E-03 6.36E-03

Mole Frac 

CO2 0.0813328 0.66667 0.66667 0 0 0 0 0 0 0 0.5084341 0 0

CO 0 0 0 0 0 0 0 0 0 0 9.55E-03 0 0

CH4 0 0 0 1 1 1 0.4 0.4 0 0 9.21E-05 0 0

H2 0 0 0 0 0 0 0 0 1 1 0.1607441 0 0

O2 0.0866518 0.33333 0.33333 0 0 0 0 0 0 0 8.18E-13 0 0

N2 0.8067052 0 0 0 0 0 0 0 0 0 0 0 0

H2O 0.0253101 0 0 0 0 0 0.6 0.6 0 0 0.3211818 1 1

Total Flow kg/sec 1.531848 0.7019892 0.7019892 0.0679693 0.0679693 0.0679693 0.182459 0.182459 7.32E-03 7.32E-03 0.8843597 0.1144896 0.1144896

Temperature C 74.99996 529.6255 529.6255 20 41.92543 30 649.698 18.46574 25 30 75.01835 20 20.21997

Pressure psia 16.2 16.2 16.2 14.7 16.7 16.7 16.7 16.7 6250 164.7 16.2 14.7 64.7

Vapor Frac 1 1 1 1 1 1 1 0.3956657 1 1 1 0 0

Enthalpy J/kmol -3.66E+07 -2.42E+08 -2.42E+08 -7.47E+07 -7.39E+07 -7.44E+07 -1.48E+08 -2.01E+08 5.68E+05 1.56E+05 -2.77E+08 -2.86E+08 -2.86E+08

Enthalpy J/kg -1.25E+06 -6.04E+06 -6.04E+06 -4.66E+06 -4.61E+06 -4.64E+06 -8.59E+06 -1.17E+07 2.82E+05 77156.4 -9.64E+06 -1.59E+07 -1.59E+07

Enthalpy MW -1.908158 -4.241803 -4.241803 -0.3165473 -0.3132112 -0.3150405 -1.567723 -2.132664 2.06E-03 5.65E-04 -8.52115 -1.817755 -1.817624

Entropy J/kmol-K 8614.975 45981.17 45981.17 -81241.23 -79709.86 -81106.81 -7561.016 -1.31E+05 -50721.69 -19631.15 1382.087 -1.64E+05 -1.64E+05

Entropy J/kg-K 292.9588 1149.352 1149.352 -5064.043 -4968.588 -5055.665 -438.9235 -7577.787 -25161.06 -9738.254 48.06386 -9094.916 -9092.205

Density kmol/cum 0.0386033 0.0167336 0.0167336 0.0416652 0.0440297 0.0457735 0.0150095 0.120156 13.48305 0.4475042 0.0387317 55.44 55.42829

Density kg/cum 1.135199 0.6694486 0.6694486 0.6684259 0.7063578 0.7343338 0.2585579 2.06984 27.18021 0.9021147 1.113741 998.7672 998.5561

Average MW 29.40678 40.00617 40.00617 16.04276 16.04276 16.04276 17.22627 17.22627 2.01588 2.01588 28.75522 18.01528 18.01528

*** ALL PHASES *** 

TDEW C 23.02893 -93.4242 -93.4242 -161.4806 -159.9087 -159.9087 89.60892 89.60892 -240.9779 73.3909 100.0252 147.6647
This report is available at no cost from the 59 

National Renewable Energy Laboratory (NREL) 

at www.nrel.gov/publications.

Figure 47. PAFC ASPEN process flow diagram

553

4.485982

SMR-IN-2

700

SMR-OUT1 6.651312

HEAT -257.6818

238

6.651312

SMR-OUT2

269

6.651312

SHIFTOUT

HL-SHIFT 15.0000 Q

200

6.651312

AN-IN

200

3.720843

H2-FLUX

200

AN-OUT 2.930469

160

STM-2-1 3.364486

42

1.121495

R-FUEL-2

123

4.485982

R-FUEL-3

47

0.216961

B-FUEL-2

200

2.930305

AN-OUT-7

614

B-AIR-4 5.832083

750

EXH-1 8.674459

46

17.718298

CATIN

200

CAT-OUT 19.578719

ENERGY 825.8894

487.5438

DCPOWER

403.2024

ACPOWER

Q

24.3772

INV-LOSS

Q

59.9642

AUXPOWER

Q

338.3456

CAT-HEAT

25

AIR-CAT 17.718298

25

1.121495

R-FUEL-1

25

0.216961

B-FUEL-1

25

5.832083

B-AIR-1

46

5.832083

B-AIR-2

25

3.364486

WATER-IN

25

WATER2 3.364486

672

4.485982

SMR-IN

250

28.253178

EXH-3

744

5.832083

B-AIR-3

15.1909

AN-HEAT

181.4798

HEAT-HQ 60

204.325696

HEAT-HQ1

80

204.325696

HEAT-HQ2

110

EXH-4 28.253178

40

201.230376

HEAT-LQ1

55

COND 5.684311

55

EXH-5 22.568868

60

201.230376

HEAT-LQ2

200

2.930176

BYPASS

25

0.000129

AN-OUT-6

200

AN-OUT-2 0.000293

25

COND2 0.000125

25

0.000168

AN-OUT-3

25

0.000168

AN-OUT-4

25

0.000168

AN-OUT-5

25

COND3 0.000000

25

0.000039

H2-LP

25

0.000039

H2-HP

40

201.230376

HEAT-LQ3

LQ-HEAT 291.0082

Q

HQ-HEAT 305.8741

Q

60

HEAT-HQ3 204.325696

-162.0568

STEAM-HT

191.4798

FC-HEAT

HL-STACK 10.0000

Q

25.0000

HL-SMR

Q

HL-BRNR 25.0000

Q

SMR

SHIFT

ANODE

MIX-1

BURNER

CATHODE

Q

POW-ELEC

Q

ECHEM

BWR-CAIR

BWR-FUEL

BWR-FBRN

BWR-ABRN

PMP-WATR

SMR-REC

BRNRECUP

AN-HX

HEAT-HQ

MIX-EXH

HX-EXH

MIX-4

BYPASS

CHILLER1

CHILLER2

PSA

COMP-PSA COMP-H2

LT-LOAD

HT-LOAD

SGEN

THRM-MGT

Q

HL-STACK

SMR-HLOS

BRB-HL Temperature (C)

Molar Flow Rate (mol/sec)

Duty (kW)

COOLER

353

EXH-2 8.674459

HQ-EXH-H 124.3943
This report is available at no cost from the 60 

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Table 4. PAFC-CHP Stream Table

AIR-CAT AN-IN AN-OUT AN-OUT-2 AN-OUT-3 AN-OUT-4 AN-OUT-5 AN-OUT-6 AN-OUT-7 B-AIR-1 B-AIR-2

BWR-CAIR ANODE BYPASS CHILLER1 COMP-PSA CHILLER2 PSA MIX-4 BURNER BWR-ABRN BRNRECUP

AN-HX ANODE BYPASS CHILLER1 COMP-PSA CHILLER2 PSA MIX-4 BWR-ABRN

VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR

Substream: MIXED

Mole Flow mol/sec

CO2 0 1.028835 1.028835 1.03E-04 1.03E-04 1.03E-04 1.03E-04 1.03E-04 1.028835 0 0

CO 0 0.05383 0.05383 5.38E-06 5.38E-06 5.38E-06 5.38E-06 5.38E-06 0.05383 0 0

CH4 0 0.03883 0.03883 3.88E-06 3.88E-06 3.88E-06 3.88E-06 3.88E-06 0.03883 0 0

H2 0 4.27683 0.555988 5.56E-05 5.56E-05 5.56E-05 5.56E-05 1.67E-05 0.555949 0 0

O2 3.720842 0 0 0 0 0 0 0 0 1.224737 1.224737

N2 13.99745 0 0 0 0 0 0 0 0 4.607345 4.607345

H2O 0 1.252986 1.252986 1.25E-04 6.67E-08 6.67E-08 4.19E-09 4.19E-09 1.252861 0 0

Mole Frac

CO2 0 0.154682 0.351082 0.351082 0.613077 0.613077 0.613305 0.798578 0.351102 0 0

CO 0 8.09E-03 0.018369 0.018369 0.032077 0.032077 0.032089 0.041783 0.01837 0 0

CH4 0 5.84E-03 0.013251 0.013251 0.023139 0.023139 0.023147 0.03014 0.013251 0 0

H2 0 0.643006 0.189727 0.189727 0.33131 0.33131 0.331433 0.129467 0.189724 0 0

O2 0.21 0 0 0 0 0 0 0 0 0.21 0.21

N2 0.79 0 0 0 0 0 0 0 0 0.79 0.79

H2O 0 0.188382 0.427572 0.427572 3.97E-04 3.97E-04 2.50E-05 3.26E-05 0.427553 0 0

Total Flow mol/sec 17.7183 6.651312 2.930469 2.93E-04 1.68E-04 1.68E-04 1.68E-04 1.29E-04 2.930305 5.832082 5.832082

Total Flow kg/sec 0.51118 0.078604 0.071103 7.11E-06 4.85E-06 4.85E-06 4.85E-06 4.77E-06 0.071101 0.168258 0.168258

Total Flow cum/sec 0.433157 0.234253 0.103045 1.03E-05 3.72E-06 1.84E-07 1.84E-07 1.36E-07 0.103038 0.142576 0.138462

Temperature C 25 200 200 200 25 25 25 24.99996 199.9913 25 45.89837

Pressure psi 14.7 16.2 16.2 16.2 16.2 314.7 314.7 314.7 16.2 14.7 16.2

Vapor Frac 1 1 1 1 1 1 1 1 1 1 1

Liquid Frac 0 0 0 0 0 0 0 0 0 0 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0

Enthalpy J/kmol -6813.77 -1.02E+08 -2.38E+08 -2.38E+08 -2.47E+08 -2.47E+08 -2.47E+08 -3.22E+08 -2.38E+08 -6813.77 6.03E+05

Enthalpy J/kg -236.176 -8.64E+06 -9.82E+06 -9.82E+06 -8.53E+06 -8.54E+06 -8.54E+06 -8.68E+06 -9.82E+06 -236.176 20917.68

Enthalpy kW -0.12073 -679.502 -698.5 -0.06985 -0.04139 -0.04144 -0.04143 -0.04145 -698.472 -0.03974 3.519564

Entropy J/kmol-K 4251.946 14208.87 7942.791 7942.791 9103.305 -16341.7 -16347.4 -17509 7943.157 4251.946 5422.795

Entropy J/kg-K 147.3791 1202.326 327.3564 327.3564 314.7087 -564.944 -565.065 -472.442 327.3638 147.3791 187.9626

Density kmol/cum 0.040905 0.028394 0.028439 0.028439 0.045154 0.912756 0.9127 0.947095 0.028439 0.040905 0.04212

Density kg/cum 1.180126 0.335552 0.69002 0.69002 1.306135 26.4025 26.40458 35.1 0.690049 1.180126 1.215191

Average MW 28.8504 11.81783 24.26344 24.26344 28.92613 28.92613 28.93019 37.06071 24.264 28.8504 28.8504

Liq Vol 60F cum/sec 9.49E-04 3.12E-04 1.12E-04 1.12E-08 8.99E-09 8.99E-09 8.98E-09 6.90E-09 1.12E-04 3.12E-04 3.12E-04
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Table 4 (cont.)

B-AIR-3 B-AIR-4 B-FUEL-1 B-FUEL-2 BYPASS CAT-OUT CATIN COND COND2 COND3 EXH-1

BRB-HL BURNER BWR-FBRN BURNER MIX-4 MIX-EXH CATHODE BRNRECUP

BRNRECUP BRB-HL BWR-FBRN BYPASS CATHODE BWR-CAIR HX-EXH CHILLER1 CHILLER2 BURNER

VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR LIQUID LIQUID LIQUID VAPOR

Substream: MIXED

Mole Flow mol/sec

CO2 0 0 0 0 1.028732 0 0 0 0 0 1.338456

CO 0 0 0 0 0.053825 0 0 0 0 0 0

CH4 0 0 0.216961 0.216961 0.038826 0 0 0 0 0 0

H2 0 0 0 0 0.555932 0 0 0 0 0 0

O2 1.224737 1.224737 0 0 0 1.860421 3.720842 0 0 0 0.408265

N2 4.607345 4.607345 0 0 0 13.99745 13.99745 0 0 0 4.607345

H2O 0 0 0 0 1.252861 3.720842 0 5.68431 1.25E-04 6.25E-08 2.320392

Mole Frac

CO2 0 0 0 0 0.351082 0 0 0 0 0 0.154299

CO 0 0 0 0 0.018369 0 0 0 0 0 0

CH4 0 0 1 1 0.013251 0 0 0 0 0 0

H2 0 0 0 0 0.189727 0 0 0 0 0 0

O2 0.21 0.21 0 0 0 0.095023 0.21 0 0 0 0.047065

N2 0.79 0.79 0 0 0 0.714932 0.79 0 0 0 0.531139

H2O 0 0 0 0 0.427572 0.190045 0 1 1 1 0.267497

Total Flow mol/sec 5.832082 5.832082 0.216961 0.216961 2.930176 19.57872 17.7183 5.68431 1.25E-04 6.25E-08 8.674459

Total Flow kg/sec 0.168258 0.168258 3.48E-03 3.48E-03 0.071096 0.518681 0.51118 0.102404 2.26E-06 1.13E-09 0.24284

Total Flow cum/sec 0.44181 0.3852 5.30E-03 5.01E-03 0.103035 0.689373 0.420658 1.04E-04 2.26E-09 1.13E-12 0.660492

Temperature C 744.2808 613.8982 25 47.17453 200 200 45.89837 54.71243 25 25 749.628

Pressure psi 16.2 16.2 14.7 16.7 16.2 16.2 16.2 16.2 16.2 314.7 16.2

Vapor Frac 1 1 1 1 1 1 1 0 0 0 1

Liquid Frac 0 0 0 0 0 0 0 1 1 1 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0

Enthalpy J/kmol 2.23E+07 1.80E+07 -7.45E+07 -7.37E+07 -2.38E+08 -4.07E+07 6.03E+05 -2.84E+08 -2.86E+08 -2.86E+08 -1.00E+08

Enthalpy J/kg 7.73E+05 6.24E+05 -4.65E+06 -4.60E+06 -9.82E+06 -1.54E+06 20917.68 -1.57E+07 -1.59E+07 -1.59E+07 -3.57E+06

Enthalpy kW 130.0613 105.0613 -16.1714 -15.9977 -698.43 -796.226 10.6927 -1612.01 -0.03579 -1.79E-05 -867.088

Entropy J/kmol-K 40986.27 36478.78 -80637.7 -79105.9 7942.791 11187.22 5422.795 -1.56E+05 -1.63E+05 -1.63E+05 39491.01

Entropy J/kg-K 1420.648 1264.412 -5026.42 -4930.94 327.3564 422.2855 187.9626 -8659.32 -9055.76 -9056.56 1410.657

Density kmol/cum 0.0132 0.01514 0.040962 0.043304 0.028439 0.028401 0.04212 54.72333 55.35149 55.40261 0.013133

Density kg/cum 0.380838 0.436807 0.657143 0.694712 0.69002 0.752395 1.215191 985.8561 997.1726 998.0935 0.367665

Average MW 28.8504 28.8504 16.04276 16.04276 24.26344 26.49207 28.8504 18.01528 18.01528 18.01528 27.99477

Liq Vol 60F cum/sec 3.12E-04 3.12E-04 1.16E-05 1.16E-05 1.12E-04 9.16E-04 9.49E-04 1.03E-04 2.26E-09 1.13E-12 3.82E-04
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Table 4 (cont.)

EXH-2 EXH-3 EXH-4 EXH-5 H2-FLUX H2-HP H2-LP HEAT-HQ1 HEAT-HQ2 HEAT-HQ3 HEAT-LQ1 HEAT-LQ2

MIX-EXH COOLER HX-EXH CATHODE COMP-H2 HEAT-HQ HT-LOAD HX-EXH LT-LOAD

BRNRECUP MIX-EXH COOLER HX-EXH ANODE COMP-H2 PSA HEAT-HQ HT-LOAD HX-EXH

VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR LIQUID LIQUID LIQUID LIQUID LIQUID

Substream: MIXED

Mole Flow mol/sec

CO2 1.338456 1.338456 1.338456 1.338456 0 0 0 0 0 0 0 0

CO 0 0 0 0 0 0 0 0 0 0 0 0

CH4 0 0 0 0 0 0 0 0 0 0 0 0

H2 0 0 0 0 3.72E+00 3.89E-05 3.89E-05 0 0 0 0 0

O2 0.408265 2.268686 2.268686 2.268686 0 0 0 0 0 0 0 0

N2 4.607345 18.6048 18.6048 18.6048 0 0 0 0 0 0 0 0

H2O 2.320392 6.041234 6.041234 0.356924 0 0 0 204.3257 204.3257 204.3257 201.2304 201.2304

Mole Frac

CO2 0.154299 0.047374 0.047374 0.059305 0 0 0 0 0 0 0 0

CO 0 0 0 0 0 0 0 0 0 0 0 0

CH4 0 0 0 0 0 0 0 0 0 0 0 0

H2 0 0 0 0 1 1 1 0 0 0 0 0

O2 0.047065 0.080298 0.080298 0.100523 0 0 0 0 0 0 0 0

N2 0.531139 0.658503 0.658503 0.824357 0 0 0 0 0 0 0 0

H2O 0.267497 0.213825 0.213825 0.015815 0 0 0 1 1 1 1 1

Total Flow mol/sec 8.674459 28.25318 28.25318 22.56887 3.72E+00 3.89E-05 3.89E-05 204.3257 204.3257 204.3257 201.2304 201.2304

Total Flow kg/sec 0.24284 0.76152 0.76152 6.59E-01 7.50E-03 7.85E-08 7.85E-08 3.680984 3.680984 3.680984 3.625221 3.625221

Total Flow cum/sec 0.404057 1.100848 0.804961 0.550538 1.31E-01 2.88E-09 4.50E-08 3.84E-03 3.92E-03 3.84E-03 3.70E-03 3.78E-03

Temperature C 352.7332 250.4135 110 54.71243 200 25 24.99996 60 80.00055 60 40 60.00641

Pressure psi 16.2 16.2 16.2 16.2 16.2 6264.7 314.7 14.7 14.7 14.7 14.7 14.7

Vapor Frac 1 1 1 1 1 1 1 0 0 0 0 0

Liquid Frac 0 0 0 0 0 0 0 1 1 1 1 1

Solid Frac 0 0 0 0 0 0 0 0 0 0 0 0

Enthalpy J/kmol -1.15E+08 -6.34E+07 -6.78E+07 -2.63E+07 5.10E+06 5.69E+05 2.19E+04 -2.83E+08 -2.82E+08 -2.83E+08 -2.85E+08 -2.83E+08

Enthalpy J/kg -4.09E+06 -2.35E+06 -2.51E+06 -9.00E+05 2.53E+06 2.82E+05 1.09E+04 -1.57E+07 -1.56E+07 -1.57E+07 -1.58E+07 -1.57E+07

Enthalpy kW -993.63 -1789.86 -1914.25 -593.222 1.90E+01 2.21E-05 8.54E-07 -57862.1 -57556.2 -57862.1 -57276.4 -56985.4

Entropy J/kmol-K 21517.58 15207.59 5424.356 6649.315 12630.5 -50741.7 -2.55E+04 -1.55E+05 -1.50E+05 -1.55E+05 -1.59E+05 -1.55E+05

Entropy J/kg-K 768.6285 564.2171 201.2491 227.6801 6265.502 -25171 -12654.9 -8593.23 -8351.62 -8593.23 -8840.82 -8593.16

Density kmol/cum 0.021468 0.025665 0.035099 0.040994 0.028379 13.50721 0.863937 53.26158 52.13249 53.26158 54.36319 53.26122

Density kg/cum 0.601003 0.691758 0.946034 1.197222 0.05721 27.22891 1.741594 959.5222 939.1815 959.5222 979.3681 959.5158

Average MW 27.99477 26.95343 26.95343 29.20464 2.01588 2.01588 2.01588 18.01528 18.01528 18.01528 18.01528 18.01528

Liq Vol 60F cum/sec 3.82E-04 1.30E-03 1.30E-03 1.20E-03 1.99E-04 2.08E-09 2.08E-09 3.69E-03 3.69E-03 3.69E-03 3.63E-03 3.63E-03
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Table 4 (cont.)

HEAT-LQ3 R-FUEL-1 R-FUEL-2 R-FUEL-3 SHIFTOUT SMR-IN SMR-IN-2 SMR-OUT1 SMR-OUT2 STM-2-1 WATER-IN WATER2

BWR-FUEL MIX-1 SMR-REC AN-HX SMR-HLOS SMR SMR-REC SHIFT MIX-1 PMP-WATR SGEN

LT-LOAD BWR-FUEL MIX-1 SHIFT SMR-REC SMR-HLOS SMR SMR-REC SGEN PMP-WATR

LIQUID VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR LIQUID LIQUID

Substream: MIXED

Mole Flow mol/sec

CO2 0 0 0 0 1.028835 0 0 0.47602 0.47602 0 0 0

CO 0 0 0 0 0.05383 0 0 0.606645 0.606645 0 0 0

CH4 0 1.121495 1.121495 1.121495 0.03883 1.121495 1.121495 0.03883 0.03883 0 0 0

H2 0 0 0 0 4.27683 0 0 3.724015 3.724015 0 0 0

O2 0 0 0 0 0 0 0.00E+00 2.05E-21 2.05E-21 0 0 0

N2 0 0 0 0 0 0 0 0 0 0 0 0

H2O 201.2304 0 0 3.364486 1.252986 3.364486 3.364486 1.805801 1.805801 3.364486 3.364486 3.364486

Mole Frac

CO2 0 0 0 0 0.154682 0 0 0.071568 0.071568 0 0 0

CO 0 0 0 0.00E+00 8.09E-03 0 0 0.091207 0.091207 0 0 0

CH4 0 1 1 2.50E-01 5.84E-03 0.25 2.50E-01 5.84E-03 5.84E-03 0 0 0

H2 0 0 0 0 0.643006 0 0 0.559892 0.559892 0 0 0

O2 0 0 0 0 0 0 0.00E+00 3.08E-22 3.08E-22 0 0 0

N2 0 0 0 0 0 0 0 0 0 0 0 0

H2O 1 0 0 0.75 0.188382 0.75 0.75 0.271496 0.271496 1 1 1

Total Flow mol/sec 201.2304 1.121495 1.121495 4.485981 6.651312 4.485981 4.485981 6.651312 6.651312 3.364486 3.364486 3.364486

Total Flow kg/sec 3.625221 0.017992 0.017992 0.078604 0.078604 0.078604 0.078604 0.078604 0.078604 0.060612 0.060612 0.060612

Total Flow cum/sec 3.70E-03 0.027379 0.026255 0.131705 0.268569 0.315634 0.275818 0.48189 0.25295 1.90E-02 6.10E-05 6.10E-05

Temperature C 40 25 41.88113 123.1612 269.2567 672.3553 553.2543 700 237.8054 160.2358 25 25.04886

Pressure psi 14.7 14.7 16.2 16.2 16.2 16.2 16.2 16.2 16.2 90 14.7 90

Vapor Frac 0 1 1 1 1 1 1 1 1 1 0 0

Liquid Frac 1 0 0 0 0 0 0 0 0 0 1 1

Solid Frac 0 0 0 0 0 0 0 0 0 0 0 0

Enthalpy J/kmol -2.85E+08 -7.45E+07 -7.39E+07 -1.97E+08 -9.99E+07 -1.74E+08 -1.79E+08 -8.21E+07 -9.76E+07 -2.38E+08 -2.86E+08 -2.86E+08

Enthalpy J/kg -1.58E+07 -4.65E+06 -4.61E+06 -1.12E+07 -8.45E+06 -9.90E+06 -1.02E+07 -6.94E+06 -8.26E+06 -1.32E+07 -1.59E+07 -1.59E+07

Enthalpy kW -57276.4 -83.5918 -82.9101 -881.993 -664.311 -778.475 -803.475 -545.793 -649.311 -799.083 -961.179 -961.14

Entropy J/kmol-K -1.59E+05 -80637.7 -79461.1 -39705.8 18712.98 -3935.13 -10231.1 42847.03 21255.5 -4.71E+04 -1.63E+05 -1.63E+05

Entropy J/kg-K -8840.82 -5026.42 -4953.08 -2266.04 1583.454 -224.581 -583.895 3625.628 1798.596 -2616.52 -9030.75 -9030.32

Density kmol/cum 54.36319 0.040962 0.042715 0.034061 0.024766 0.014213 0.016264 0.013803 0.026295 0.177513 55.173 55.17038

Density kg/cum 979.3681 0.657143 0.685271 0.596821 0.292677 0.249035 0.284985 0.163116 0.310749 3.19794 993.957 993.9099

Average MW 18.01528 16.04276 16.04276 17.52215 11.81783 17.52215 17.52215 11.81783 11.81783 18.01528 18.01528 18.01528

Liq Vol 60F cum/sec 3.63E-03 6.01E-05 6.01E-05 1.21E-04 3.12E-04 1.21E-04 1.21E-04 2.92E-04 2.92E-04 6.07E-05 6.07E-05 6.07E-05
This report is available at no cost from the 64 

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Table 5. PAFC-CHHP Stream Table

AFMIX2 AIR+FUEL AIR-CAT AN-IN AN-OUT B-AIR-1 B-AIR-2 B-AIR-3 B-AIR-4 B-FUEL-1 B-FUEL-2 CAT-OUT

BRNR2 CMP-BRN2 BWR-CAIR ANODE MIX-4 BWR-ABRN BRNRECUP BURNER BRB-HL BWR-FBRN BURNER MIX-EXH

CMP-BRN2 BYPASS ANODE BWR-ABRN BRNRECUP BURNER BWR-FBRN CATHODE

VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR

Substream: MIXED

Mole Flow mol/sec

CO2 0 0 0 0.106051 0.106051 0 0 0 1.220009 0 0 0

CO 0 0 0 5.82E-03 5.82E-03 0 0 0 0 0 0 0

CH4 0.130541 0.130541 0 4.01E-03 4.01E-03 0 0 0 0 0.061131 0.061131 0

H2 0 0 0 0.441678 0.057418 0 0 0 0 0 0 0

O2 0.287178 0.287178 0.38426 0 0 1.135841 1.135841 1.135841 0.378614 0 0 0.19213

N2 1.080339 1.080339 1.445548 0 0 4.272924 4.272924 4.272924 4.272924 0 0 1.445548

H2O 0 0 0 0.129737 0.129737 0 0 0 1.383646 0 0 0.38426

Mole Frac

CO2 0 0 0 0.154301 0.349955 0 0 0 0.168157 0 0 0

CO 0 0 0 8.47E-03 0.019218 0 0 0 0 0 0 0

CH4 0.08714 0.08714 0 5.84E-03 0.013241 0 0 0 0 1 1 0

H2 0 0 0 0.642625 0.189472 0 0 0 0 0 0 0

O2 0.1917 0.1917 0.21 0 0 0.21 0.21 0.21 0.052185 0 0 0.095023

N2 0.72116 0.72116 0.79 0 0 0.79 0.79 0.79 0.588947 0 0 0.714932

H2O 0 0 0 0.188762 0.428114 0 0 0 0.190711 0 0 0.190045

Total Flow mol/sec 1.498057 1.498057 1.829807 0.687302 0.303043 5.408765 5.408765 5.408765 7.255193 0.061131 0.061131 2.021937

Total Flow kg/sec 0.041548 0.041548 0.052791 8.12E-03 7.35E-03 0.156045 0.156045 0.156045 0.210434 9.81E-04 9.81E-04 0.053565

Total Flow cum/sec 0.034536 0.036619 0.044733 0.024206 0.010656 0.132227 0.128412 0.409119 0.600582 1.49E-03 1.41E-03 0.071193

Temperature C 36.716 25 25 200 200 25 45.89837 742.734 838.7326 25 47.17113 200

Pressure psi 16.2 14.7 14.7 16.2 16.2 14.7 16.2 16.2 16.2 14.7 16.7 16.2

Vapor Frac 1 1 1 1 1 1 1 1 1 1 1 1

Liquid Frac 0 0 0 0 0 0 0 0 0 0 0 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0 0

Enthalpy J/kmol -6.15E+06 -6.50E+06 -6813.77 -1.02E+08 -2.38E+08 -6813.77 6.03E+05 2.22E+07 -8.36E+07 -7.45E+07 -7.37E+07 -4.07E+07

Enthalpy J/kg -2.22E+05 -2.34E+05 -236.176 -8.64E+06 -9.82E+06 -236.176 20917.68 7.71E+05 -2.88E+06 -4.65E+06 -4.60E+06 -1.54E+06

Enthalpy kW -9.21686 -9.7391 -0.01247 -70.2048 -72.1667 -0.03685 3.264099 120.3335 -606.459 -4.55646 -4.5075 -82.228

Entropy J/kmol-K -345.674 -685.11 4251.946 14236.88 8005.565 4251.946 5422.795 40935.68 45534.83 -80637.7 -79106.3 11187.22

Entropy J/kg-K -12.4638 -24.7026 147.3791 1204.695 330.1708 147.3791 187.9626 1418.895 1569.919 -5026.42 -4930.96 422.2855

Density kmol/cum 0.043376 0.040909 0.040905 0.028394 0.028439 0.040905 0.04212 0.013221 0.01208 0.040962 0.043304 0.028401

Density kg/cum 1.203008 1.134587 1.180126 0.335553 0.689546 1.180126 1.215191 0.381417 0.350383 0.657143 0.69472 0.752395

Average MW 27.73434 27.73434 28.8504 11.81783 24.24674 28.8504 28.8504 28.8504 29.00458 16.04276 16.04276 26.49207

Liq Vol 60F cum/sec 8.02E-05 8.02E-05 9.80E-05 3.22E-05 1.16E-05 2.90E-04 2.90E-04 2.90E-04 3.39E-04 3.27E-06 3.27E-06 9.46E-05
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Table 5 (cont.)

CATIN COND1 COND2 COND3 EXH EXH-1 EXH-2 EXH-3 EXH-4 EXH-5 EXH-6 EXH-7

CATHODE BRNRECUP SGENBRNR MIX-EXH COOLER HX-EXH B4

BWR-CAIR B4 CHILLER1 CHILLER2 BRNR2 BRB-HL BRNRECUP SGENBRNR MIX-EXH COOLER HX-EXH B4

VAPOR LIQUID LIQUID LIQUID VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR MIXED VAPOR

Substream: MIXED

Mole Flow mol/sec

CO2 0 7.76E-03 0 0 0.130541 1.220009 1.220009 1.220009 1.220009 1.220009 1.220009 1.212249

CO 0 0 0 0 0 0 0 0 0 0 0 0

CH4 0 0 0 0 0 0 0 0 0 0 0 0

H2 0 0 0 0 0 0 0 0 0 0 0 0

O2 0.38426 8.07E-04 0 0 0.026096 0.378614 0.378614 0.378614 0.570743 0.570743 0.570743 0.569936

N2 1.445548 3.08E-03 0 0 1.080339 4.272924 4.272924 4.272924 5.718472 5.718472 5.718472 5.715392

H2O 0 1.59497 1.165645 1.78E-03 0.261081 1.383646 1.383646 1.383646 1.767905 1.767905 1.767905 0.172936

Mole Frac

CO2 0 4.83E-03 0 0 0.08714 0.168157 0.168157 0.168157 0.131507 0.131507 0.131507 0.15804

CO 0 0 0 0 0 0 0 0 0 0 0 0

CH4 0 0 0 0 0 0 0 0 0 0 0 0

H2 0 0 0 0 0 0 0 0 0 0 0 0

O2 0.21 5.02E-04 0 0 0.01742 0.052185 0.052185 0.052185 0.061522 0.061522 0.061522 0.074302

N2 0.79 1.92E-03 0 0 0.72116 0.588947 0.588947 0.588947 0.616405 0.616405 0.616405 0.745112

H2O 0 0.99275 1 1 0.17428 0.190711 0.190711 0.190711 0.190566 0.190566 0.190566 0.022546

Total Flow mol/sec 1.829807 1.606618 1.165645 1.78E-03 1.498057 7.255193 7.255193 7.255193 9.27713 9.27713 9.27713 7.670512

Total Flow kg/sec 0.052791 0.029188 0.020999 3.21E-05 0.041548 0.210434 0.210434 0.210434 0.263999 0.263999 0.263999 0.234812

Total Flow cum/sec 0.043442 2.92E-05 2.11E-05 3.21E-08 0.046512 0.552355 0.311657 0.233747 0.30463 0.264292 0.175597 0.16783

Temperature C 45.89837 21.15891 25 25 144.2173 749.4543 304.0224 160 168.2637 110 40.43257 21.15891

Pressure psi 16.2 16.2 16.2 164.7 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2

Vapor Frac 1 0 0 0 1 1 1 1 1 1 0.811423 1

Liquid Frac 0 1 1 1 0 0 0 0 0 0 0.188577 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0 0

Enthalpy J/kmol 6.03E+05 -2.86E+08 -2.86E+08 -2.86E+08 -7.28E+07 -8.70E+07 -1.03E+08 -1.08E+08 -9.33E+07 -9.52E+07 -1.06E+08 -6.78E+07

Enthalpy J/kg 20917.68 -1.57E+07 -1.59E+07 -1.59E+07 -2.62E+06 -3.00E+06 -3.56E+06 -3.72E+06 -3.28E+06 -3.34E+06 -3.71E+06 -2.21E+06

Enthalpy kW 1.104258 -459.236 -333.168 -0.50869 -108.987 -631.459 -748.538 -783.405 -865.633 -882.952 -979.079 -519.843

Entropy J/kmol-K 5422.795 -1.62E+05 -1.63E+05 -1.63E+05 8947.442 42304.65 21698.2 12128.89 12250.03 7715.175 -24368.1 4782.811

Entropy J/kg-K 187.9626 -8942.05 -9055.76 -9056.23 322.6124 1458.551 748.0956 418.1714 430.4754 271.1172 -856.315 156.2385

Density kmol/cum 0.04212 54.988 55.35149 55.37695 0.032208 0.013135 0.023279 0.031039 0.030454 0.035102 0.052832 0.045704

Density kg/cum 1.215191 998.9694 997.1726 997.6312 0.893271 0.380976 0.67521 0.900263 0.866623 0.998893 1.50344 1.399105

Average MW 28.8504 18.16704 18.01528 18.01528 27.73434 29.00458 29.00458 29.00458 28.45698 28.45698 28.45698 30.61224

Liq Vol 60F cum/sec 9.80E-05 2.94E-05 2.10E-05 3.21E-08 7.10E-05 3.39E-04 3.39E-04 3.39E-04 4.34E-04 4.34E-04 4.34E-04 4.05E-04
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Table 5 (cont.)

H2-FLUX H2-HP H2-LP HEAT-LQ1 HEAT-LQ2 HEAT-LQ3 R-FUEL-1 R-FUEL-2 R-FUEL-3 SHIFTOUT SMR-IN SMR-IN-2

CATHODE COMP-H2 HX-EXH LT-LOAD BWR-FUEL MIX-1 SMR-REC AN-HX SMR-HLOS SMR

ANODE COMP-H2 PSA HX-EXH LT-LOAD BWR-FUEL MIX-1 SHIFT SMR-REC SMR-HLOS

VAPOR VAPOR VAPOR LIQUID LIQUID LIQUID VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR

Substream: MIXED

Mole Flow mol/sec

CO2 0 0 0 0 0 0 0 0 0 1.060514 0 0

CO 0 0 0 0 0 0 0 0 0 0.05824 0 0

CH4 0 0 0 0 0 0 1.158878 1.158878 1.158878 0.040125 1.158878 1.158878

H2 0.38426 2.981324 2.981324 0 0 0 0 0 0 4.416776 0 0

O2 0 0 0 0 0 0 0 0 0 0 0 0

N2 0 0 0 0 0 0 0 0 0 0 0 0

H2O 0 0 0 66.49669 66.49669 66.49669 0 0 3.476636 1.297367 3.476636 3.476636

Mole Frac

CO2 0 0 0 0 0 0 0 0 0 0.154301 0 0

CO 0 0 0 0 0 0 0 0 0 8.47E-03 0 0

CH4 0 0 0 0 0 0 1 1 0.25 5.84E-03 0.25 0.25

H2 1 1 1 0 0 0 0 0 0 0.642625 0 0

O2 0 0 0 0 0 0 0 0 0 0 0 0

N2 0 0 0 0 0 0 0 0 0 0 0 0

H2O 0 0 0 1 1 1 0 0 0.75 0.188762 0.75 0.75

Total Flow mol/sec 0.38426 2.981324 2.981324 66.49669 66.49669 66.49669 1.158878 1.158878 4.635514 6.873022 4.635514 4.635514

Total Flow kg/sec 7.75E-04 6.01E-03 6.01E-03 1.197956 1.197956 1.197956 0.018592 0.018592 0.081224 0.081224 0.081224 0.081224

Total Flow cum/sec 0.01354 2.21E-04 6.55E-03 1.22E-03 1.25E-03 1.22E-03 0.028292 0.02713 0.136095 0.279154 0.325642 0.285835

Temperature C 200 25 25.00004 40 59.99897 40 25 41.88113 123.1612 272.446 670.8693 555.6345

Pressure psi 16.2 6264.7 164.7 14.7 14.7 14.7 14.7 16.2 16.2 16.2 16.2 16.2

Vapor Frac 1 1 1 0 0 0 1 1 1 1 1 1

Liquid Frac 0 0 0 1 1 1 0 0 0 0 0 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0 0

Enthalpy J/kmol 5.10E+06 5.69E+05 11355.15 -2.85E+08 -2.83E+08 -2.85E+08 -7.45E+07 -7.39E+07 -1.97E+08 -9.98E+07 -1.74E+08 -1.79E+08

Enthalpy J/kg 2.53E+06 2.82E+05 5632.848 -1.58E+07 -1.57E+07 -1.58E+07 -4.65E+06 -4.61E+06 -1.12E+07 -8.44E+06 -9.91E+06 -1.02E+07

Enthalpy kW 1.959141 1.696543 0.033853 -18927 -18830.9 -18927 -86.3782 -85.6738 -911.393 -685.624 -804.755 -829.755

Entropy J/kmol-K 12630.5 -50741.7 -20110.7 -1.59E+05 -1.55E+05 -1.59E+05 -80637.7 -79461.1 -39705.8 18935.2 -4010.69 -10100.1

Entropy J/kg-K 6265.502 -25171 -9976.16 -8840.82 -8593.25 -8840.82 -5026.42 -4953.08 -2266.04 1602.258 -228.892 -576.42

Density kmol/cum 0.028379 13.50721 0.454974 54.36319 53.26163 54.36319 0.040962 0.042715 0.034061 0.024621 0.014235 0.016217

Density kg/cum 0.05721 27.22891 0.917173 979.3681 959.5232 979.3681 0.657143 0.685271 0.596821 0.290965 0.249428 0.284165

Average MW 2.01588 2.01588 2.01588 18.01528 18.01528 18.01528 16.04276 16.04276 17.52215 11.81783 17.52215 17.52215

Liq Vol 60F cum/sec 2.06E-05 1.60E-04 1.60E-04 1.20E-03 1.20E-03 1.20E-03 6.21E-05 6.21E-05 1.25E-04 3.22E-04 1.25E-04 1.25E-04
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Table 5 (cont.)

SMR-OUT1 SMR-OUT2 STM-2-1 SYNGAS1 SYNGAS2 SYNGAS3 SYNGAS4 SYNGAS5 SYNGAS6 SYNGAS7 WATER-IN WATER2

SMR-REC SHIFT MIX-1 BYPASS CHILLER1 COMP-PSA CHILLER2 PSA MIX-4 BURNER PMP-WATR SGEN

SMR SMR-REC SGEN AN-HX BYPASS CHILLER1 COMP-PSA CHILLER2 PSA MIX-4 PMP-WATR

VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR VAPOR LIQUID LIQUID

Substream: MIXED

Mole Flow mol/sec

CO2 0.491887 0.491887 0 1.060514 0.954463 0.954463 0.954463 0.954463 0.954463 1.060514 0 0

CO 0.626867 0.626867 0 0.05824 0.052416 0.052416 0.052416 0.052416 0.052416 0.05824 0 0

CH4 0.040125 0.040125 0 0.040125 0.036112 0.036112 0.036112 0.036112 0.036112 0.040125 0 0

H2 3.848149 3.848149 0 4.416776 3.975099 3.975099 3.975099 3.975099 0.993775 1.051193 0 0

O2 2.12E-21 2.12E-21 0 0 0 0 0 0 0 0 0 0

N2 0 0 0 0 0 0 0 0 0 0 0 0

H2O 1.865994 1.865994 3.476636 1.297367 1.167631 1.99E-03 1.99E-03 2.05E-04 2.05E-04 0.129942 3.476636 3.476636

Mole Frac

CO2 0.071568 0.071568 0 0.154301 0.154301 0.190129 0.190129 0.190197 0.46857 0.453209 0 0

CO 0.091207 0.091207 0 8.47E-03 8.47E-03 0.010441 0.010441 0.010445 0.025732 0.024889 0 0

CH4 5.84E-03 5.84E-03 0 5.84E-03 5.84E-03 7.19E-03 7.19E-03 7.20E-03 0.017728 0.017147 0 0

H2 0.559892 0.559892 0 0.642625 0.642625 0.791841 0.791841 0.792121 0.487869 0.449225 0 0

O2 3.08E-22 3.08E-22 0 0 0 0 0 0 0 0 0 0

N2 0 0 0 0 0 0 0 0 0 0 0 0

H2O 0.271496 0.271496 1 0.188762 0.188762 3.95E-04 3.95E-04 4.09E-05 1.01E-04 0.055531 1 1

Total Flow mol/sec 6.873022 6.873022 3.476636 6.873022 6.18572 5.020074 5.020074 5.018295 2.036971 2.340013 3.476636 3.476636

Total Flow kg/sec 0.081224 0.081224 0.062633 0.081224 0.073102 0.052102 0.052102 0.05207 0.04606 0.053408 0.062633 0.062633

Total Flow cum/sec 0.497953 0.262146 0.019585 0.242061 0.217855 0.11144 0.010987 0.010983 4.40E-03 0.05563 6.30E-05 6.30E-05

Temperature C 700 239.298 160.2358 200 200 25 25 25 25.00004 46.61996 25 25.04886

Pressure psi 16.2 16.2 90 16.2 16.2 16.2 164.7 164.7 164.7 16.2 14.7 90

Vapor Frac 1 1 1 1 1 1 1 1 1 1 0 0

Liquid Frac 0 0 0 0 0 0 0 0 0 0 1 1

Solid Frac 0 0 0 0 0 0 0 0 0 0 0 0

Enthalpy J/kmol -8.21E+07 -9.76E+07 -2.38E+08 -1.02E+08 -1.02E+08 -7.66E+07 -7.66E+07 -7.66E+07 -1.89E+08 -1.95E+08 -2.86E+08 -2.86E+08

Enthalpy J/kg -6.94E+06 -8.26E+06 -1.32E+07 -8.64E+06 -8.64E+06 -7.38E+06 -7.38E+06 -7.38E+06 -8.34E+06 -8.55E+06 -1.59E+07 -1.59E+07

Enthalpy kW -563.986 -670.624 -825.719 -702.048 -631.843 -384.565 -384.654 -384.223 -384.35 -456.516 -993.219 -993.178

Entropy J/kmol-K 42847.03 21349.58 -47137.3 14236.88 14236.88 4942.298 -14417.4 -14424.7 -10904.3 9826.388 -1.63E+05 -1.63E+05

Entropy J/kg-K 3625.628 1806.557 -2616.52 1204.695 1204.695 476.1918 -1389.12 -1390.19 -482.234 430.5319 -9030.75 -9030.32

Density kmol/cum 0.013803 0.026218 0.177513 0.028394 0.028394 0.045047 0.456929 0.456921 0.463175 0.042064 55.173 55.17038

Density kg/cum 0.163116 0.309843 3.19794 0.335553 0.335553 0.467537 4.742377 4.741055 10.47337 0.960054 993.957 993.9099

Average MW 11.81783 11.81783 18.01528 11.81783 11.81783 10.3788 10.3788 10.37609 22.61214 22.82383 18.01528 18.01528

Liq Vol 60F cum/sec 3.02E-04 3.02E-04 6.28E-05 3.22E-04 2.90E-04 2.69E-04 2.69E-04 2.69E-04 1.09E-04 1.21E-04 6.28E-05 6.28E-05
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Figure 48. SOFC ASPEN process flow diagram

Temperature (C)

Pressure (psia)

Molar Flow Rate (mol/min)

Duty (kW)

Power(kW)

708

17

895.3

FUEL-HOT

573

17

949.8

REFOUT

HL-REF 10.00

Q

652

17

949.8

ANODIN

669

16

O2FLUX 225.2

800

16

1167.7

ANODOUT1

NRG-TOT 1373.92

669

16

2958.3

CAT-IN

669

16

2733.1

CAT-COLD

AN-HEAT2 192.07

797

16

2733.1

CAT-OUT

20

15

136.3

FUELIN

34

17

136.3

FUEL-1

CH4-CMP 1.23

W

20

15

2958.3

AIRIN

33

16

2958.3

AIR-1

AIR-CMP 20.24

W

80

30

WTR03 8129.5

60

30

8129.5

WTR04

HEAT-1 204.37

295

16

408.7

ANODOUT4

319

16

408.7

ANODH2-1

12.00

HL-SHFT

Q

30

165

226.5

PSA-HP

30

165

AN-LOWH2 147.9

30

165

78.6

H2LP

70

16

2958.3

AIR-WRM

159

16

2733.1

COMBAIR

499

16

ANODOUT3 1167.7

499

16

759.0

RECLP

499

16

H2RCVRY 408.7

507

17

RECHP1 759.0

423

17

895.3

FUEL-MIX

1142.05

DC-POWER

INV-LOSS 79.94

Q

1000.10

AC-POWER

Q

AUXCONST 62.00

Q

800

16

ANOUT1A 467.1

634

16

467.1

ANOUT1B

735

16

1156.0

ANOUT2A

497

16

ANOUT2B 1156.0

499

16

344.8

ANOUT3A

255

16

344.8

ANOUT3B

60

30

8129.5

WTR01

184

16

2873.0

BRNOUT-2

76

30

8129.5

WTR02

68

16

2873.0

EXHAUST

166

16

ANODH2-2 408.7

AN-HEAT 231.88

800

16

ANOUTBYP 700.6

735

16

1167.7

ANODOUT2

499

16

63.9

AIRFLBYP

735

16

REFBYP 11.7

159

16

2662.3

BRNBYPAS

410

16

210.7

BRNOUT1B

159

16

70.8

BURN-IN

305

165

FBRNIN2 147.9

592

16

210.7

BRNOUT-1

18.23

HL-BRNR

Q

50

6250

78.6

H2HP

H2-CMP 24.61

W

REC-CMP 4.23

W

30

165

FBRNIN1 147.9

39.81

HL-STACK

Q

12.00

HL-PIPES

Q

192.37

HEAT

Q

166

16

PSA-IN 408.7

30

16

WATOUT1 182.2

PSAWRK 57.02

W

0.0

PSA-BYP

PREREFRM ANODE

CATHODE

CATHEAT

CMP-FUEL

CMP-AIR

TRM-LOAD

SHIFT

PSA

AIRECOUP

RECYCLE

RECMIX

Q

AC-CONV

HX-REF HX-ANODE

HX-AIR

EXHCOOLR

REFCOOL

DC-CONV Q

ANBYP

ANBYMIX

FLAIRBYP FLABYMIX

REFBYP

REFBYMIX

BRN-SPLT BRNMIX

COMBCAT

H2-CMP

REC-CMP

BRNRREC

Q

HL-STACK

Q

HL-PIPES

PSACMPR

PSA-BYP

FBRNMIX
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Table 6. SOFC-CHP Stream Table

AIR-1 AIR-WRM AIRFLBYP AIRIN AN-LOWH2 ANODH2-1 ANODH2-2 ANODIN ANODOUT1 ANODOUT2 ANODOUT3

Mole Flow mol/min 

CH4 0 0 2.69E-04 0 1.63E-09 1.64E-03 1.64E-03 109.0179 4.92E-03 4.92E-03 4.92E-03

N2 2337.046 2337.046 0 2337.046 0 0 0 0 0 0 0

CO 0 0 4.723909 0 2.18E-06 2.187676 2.187676 51.71445 86.36537 86.36537 86.36475

CO2 0 0 16.56564 0 1.31E-04 134.0414 134.0414 228.5366 302.8631 302.8631 302.8609

H2 0 0 10.07224 0 1.39E-05 92.49124 92.49124 233.135 184.1467 184.1467 184.1454

H2O 0 0 32.50686 0 7.70E-07 179.9669 179.9669 327.3671 594.3101 594.3101 594.3059

O2 621.2402 621.2402 2.64E-16 621.2402 0 1.11E-34 1.11E-34 2.43E-22 4.82E-15 4.82E-15 4.82E-15

C 0 0 3.59E-28 0 0 8.98E-36 8.98E-36 2.11E-34 6.57E-27 6.57E-27 6.57E-27

Mole Frac 

CH4 0 0 4.21E-06 0 1.10E-05 4.00E-06 4.00E-06 0.1147833 4.21E-06 4.21E-06 4.21E-06

N2 0.79 0.79 0 0.79 0 0 0 0 0 0 0

CO 0 0 0.0739625 0 0.0147685 5.35E-03 5.35E-03 0.0544493 0.0739625 0.0739625 0.0739625

CO2 0 0 0.2593694 0 0.8862063 0.3279791 0.3279791 0.2406228 0.2593694 0.2593694 0.2593694

H2 0 0 0.1577017 0 0.0938087 0.2263121 0.2263121 0.2454644 0.1577017 0.1577017 0.1577017

H2O 0 0 0.5089622 0 5.21E-03 0.4403519 0.4403519 0.3446801 0.5089622 0.5089622 0.5089622

O2 0.21 0.21 4.13E-18 0.21 0 2.72E-37 2.72E-37 2.56E-25 4.13E-18 4.13E-18 4.13E-18

C 0 0 5.63E-30 0 0 2.20E-38 2.20E-38 2.22E-37 5.63E-30 5.63E-30 5.63E-30

Total Flowmol/min 2958.286 2958.286 63.86891 2958.286 1.48E-04 408.6889 408.6889 949.7711 1167.69 1167.69 1167.682

Total Flowkg/sec 1.422462 1.422462 0.0244549 1.422462 9.78E-08 0.1564841 0.1564841 0.3270487 0.4471005 0.4471005 0.4470974

Total Flowl/min 67342.52 75521.75 3671.093 71141.18 3.27E-04 18015.12 13381.06 63466.39 93278.45 87591.12 67116.67

Temperature C 32.66295 69.80611 499.0194 20 30 319.0265 166.6999 652.2575 800 734.5684 499.0194

Pressurepsia 16.2 16.2 16.2 14.7 164.6959 16.2 16.2 16.7 16.2 16.2 16.2

Vapor Frac 1 1 1 1 0.9976798 1 1 1 1 1 1

Liquid Frac 0 0 0 0 2.32E-03 0 0 0 0 0 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0

EnthalpyJ/kmol 2.24E+05 1.31E+06 -2.16E+08 -1.46E+05 -3.52E+08 -2.26E+08 -2.31E+08 -1.68E+08 -2.03E+08 -2.06E+08 -2.16E+08

EnthalpyJ/kg 7749.924 45364.87 -9.40E+06 -5055.209 -8.86E+06 -9.82E+06 -1.01E+07 -8.14E+06 -8.86E+06 -8.98E+06 -9.40E+06

EnthalpykW 11.02398 64.52982 -229.8271 -7.190845 -8.66E-04 -1536.139 -1574.707 -2663.438 -3959.363 -4013.741 -4201.81

Entropy J/kmol-K 4203.506 7552.521 28247.81 3777.6 -12647.01 14756.25 3717.578 34968.23 41842.66 39156.42 28247.81

Entropy J/kg-K 145.7001 261.7822 1229.578 130.9375 -318.5765 642.3141 161.8197 1692.501 1821.338 1704.411 1229.578

Density kmol/cum 0.0439289 0.0391713 0.0173977 0.0415833 0.451561 0.0226858 0.0305423 0.0149649 0.0125183 0.0133311 0.0173977

Density kg/cum 1.267368 1.130108 0.3996897 1.199695 17.92629 0.5211757 0.7016667 0.3091861 0.2875909 0.3062643 0.3996897

Average MW 28.8504 28.8504 22.97359 28.8504 39.69849 22.97358 22.97358 20.66069 22.97359 22.97359 22.97359

Liq Vol 60F l/min 158.4393 158.4393 2.266431 158.4393 7.89E-06 15.49825 15.49825 39.24356 41.43628 41.43628 41.43598

*** ALL PHASES ***

TDEWC -190.1721 -190.1721 84.61444 -191.015 38.16618 80.98133 80.98133 75.73295 84.61444 84.61444 84.61444

Substream: $TOTAL 

Total Flowkg/sec 1.422462 1.422462 0.0244549 1.422462 9.78E-08 0.1564841 0.1564841 0.3270487 0.4471005 0.4471005 0.4470974

EnthalpykW 11.02398 64.52982 -229.8271 -7.190845 -8.66E-04 -1536.139 -1574.707 -2663.438 -3959.363 -4013.741 -4201.81
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Table 6 (cont.)

ANODOUT4 ANOUT1A ANOUT1B ANOUT2A ANOUT2B ANOUT3A ANOUT3B ANOUTBYP BRNBYPAS BRNOUT-1 BRNOUT-2

Mole Flow mol/min 

CH4 1.72E-03 1.97E-03 1.97E-03 4.87E-03 4.87E-03 1.45E-03 1.45E-03 2.95E-03 0 0 0

N2 0 0 0 0 0 0 0 0 1232.888 1104.158 2337.046

CO 30.22766 34.54615 34.54615 85.5011 85.5011 25.50376 25.50376 51.81922 0 0 0

CO2 106.0013 121.1452 121.1452 299.8323 299.8323 89.43569 89.43569 181.7178 0 136.2307 136.2307

H2 64.4509 73.6587 73.6587 182.304 182.304 54.37867 54.37867 110.488 0 0 0

H2O 208.0071 237.7241 237.7241 588.3628 588.3628 175.5002 175.5002 356.5861 0 272.4612 272.4612

O2 1.69E-15 1.93E-15 1.93E-15 4.78E-15 4.78E-15 1.42E-15 1.42E-15 2.89E-15 208.9369 139.7784 348.7152

C 2.30E-27 2.63E-27 2.63E-27 6.50E-27 6.50E-27 1.94E-27 1.94E-27 3.94E-27 0 0 0

Mole Frac 

CH4 4.21E-06 4.21E-06 4.21E-06 4.21E-06 4.21E-06 4.21E-06 4.21E-06 4.21E-06 0 0 0

N2 0 0 0 0 0 0 0 0 0.8550886 0.6681225 0.7552372

CO 0.0739625 0.0739625 0.0739625 0.0739625 0.0739625 0.0739625 0.0739625 0.0739625 0 0 0

CO2 0.2593694 0.2593694 0.2593694 0.2593694 0.2593694 0.2593694 0.2593694 0.2593694 0 0.0824327 0.0440241

H2 0.1577017 0.1577017 0.1577017 0.1577017 0.1577017 0.1577017 0.1577017 0.1577017 0 0 0

H2O 0.5089622 0.5089622 0.5089622 0.5089622 0.5089622 0.5089622 0.5089622 0.5089622 0 0.1648653 0.0880482

O2 4.13E-18 4.13E-18 4.13E-18 4.13E-18 4.13E-18 4.13E-18 4.13E-18 4.13E-18 0.1449114 0.0845794 0.1126904

C 5.63E-30 5.63E-30 5.63E-30 5.63E-30 5.63E-30 5.63E-30 5.63E-30 5.63E-30 0 0 0

Total Flowmol/min 408.6887 467.0761 467.0761 1156.005 1156.005 344.8198 344.8198 700.6141 1441.825 1652.628 3094.453

Total Flowkg/sec 0.1564841 0.1788402 0.1788402 0.4426264 0.4426264 0.1320291 0.1320291 0.2682603 0.6870536 0.7718001 1.458854

Total Flowl/min 17275.67 37311.38 31550.39 86714.59 66233.67 19819.74 13565.46 55967.07 46395.47 1.07E+05 1.52E+05

Temperature C 294.7202 800 634.3024 734.5684 496.5577 499.0194 255.3551 800 159.1346 595.6236 387.9136

Pressurepsia 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2

Vapor Frac 1 1 1 1 1 1 1 1 1 1 1

Liquid Frac 0 0 0 0 0 0 0 0 0 0 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0

EnthalpyJ/kmol -2.24E+08 -2.03E+08 -2.10E+08 -2.06E+08 -2.16E+08 -2.16E+08 -2.25E+08 -2.03E+08 3.93E+06 -5.37E+07 -2.74E+07

EnthalpyJ/kg -9.74E+06 -8.86E+06 -9.16E+06 -8.98E+06 -9.40E+06 -9.40E+06 -9.80E+06 -8.86E+06 1.37E+05 -1.92E+06 -9.69E+05

EnthalpykW -1524.139 -1583.745 -1638.124 -3973.572 -4161.672 -1240.806 -1294.312 -2375.618 94.41278 -1478.451 -1413.964

Entropy J/kmol-K 16451.17 41842.66 34776.55 39156.42 28121.18 28247.81 13796.08 41842.66 13507.56 34763.92 26599

Entropy J/kg-K 716.0907 1821.338 1513.762 1704.411 1224.066 1229.578 600.5191 1821.338 472.441 1240.646 940.3428

Density kmol/cum 0.0236568 0.0125183 0.0148041 0.0133311 0.0174534 0.0173977 0.0254189 0.0125183 0.0310768 0.0154632 0.0203218

Density kg/cum 0.5434836 0.2875909 0.3401039 0.3062643 0.400968 0.3996897 0.5839644 0.2875909 0.8885181 0.4332923 0.5748341

Average MW 22.97359 22.97359 22.97359 22.97359 22.97359 22.97359 22.97359 22.97359 28.591 28.02082 28.28649

Liq Vol 60F l/min 14.50259 16.57451 16.57451 41.02162 41.02162 12.23616 12.23616 24.86176 77.22097 78.83665 156.0576

*** ALL PHASES ***

TDEWC 84.61444 84.61444 84.61444 84.61444 84.61444 84.61444 84.61444 84.61444 -191.3545 58.31881 45.50493

Substream: $TOTAL 

Total Flowkg/sec 0.1564841 0.1788402 0.1788402 0.4426264 0.4426264 0.1320291 0.1320291 0.2682603 0.6870536 0.7718001 1.458854

EnthalpykW -1524.139 -1583.745 -1638.124 -3973.572 -4161.672 -1240.806 -1294.312 -2375.618 94.41278 -1478.451 -1413.964
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Table 6 (cont.)

BRNOUT1B BURN-IN CAT-COLD CAT-IN CAT-OUT COMBAIR EXHAUST FBRNIN1 FBRNIN2 FUEL-1 FUEL-HOT

Mole Flow mol/min 

CH4 0 0 0 0 0 0 0 1.64E-03 1.64E-03 136.2692 136.2724

N2 1104.158 1104.158 2337.046 2337.046 2337.046 2337.046 2337.046 0 0 0 0

CO 0 0 0 0 0 0 0 2.187676 2.187676 0 56.13707

CO2 136.2307 0 0 0 0 0 136.2307 134.0414 134.0414 0 196.8595

H2 0 0 0 0 0 0 0 92.49116 92.49116 0 119.6945

H2O 272.4612 0 0 0 0 0 272.4612 179.9667 179.9667 0 386.2987

O2 139.7784 187.1211 396.0579 621.2402 396.0579 396.0579 348.7152 1.11E-34 1.11E-34 0 3.14E-15

C 0 0 0 0 0 0 0 8.98E-36 8.98E-36 0 4.27E-27

Mole Frac 

CH4 0 0 0 0 0 0 0 4.00E-06 4.00E-06 1 0.152215

N2 0.6681225 0.8550886 0.8550886 0.79 0.8550886 0.8550886 0.7552372 0 0 0 0

CO 0 0 0 0 0 0 0 5.35E-03 5.35E-03 0 0.0627046

CO2 0.0824327 0 0 0 0 0 0.0440241 0.3279793 0.3279793 0 0.2198904

H2 0 0 0 0 0 0 0 0.2263121 0.2263121 0 0.1336977

H2O 0.1648653 0 0 0 0 0 0.0880482 0.4403517 0.4403517 0 0.4314923

O2 0.0845794 0.1449114 0.1449114 0.21 0.1449114 0.1449114 0.1126904 2.72E-37 2.72E-37 0 3.50E-18

C 0 0 0 0 0 0 0 2.20E-38 2.20E-38 0 4.77E-30

Total Flowmol/min 1652.628 1291.279 2733.104 2958.286 2733.104 2733.104 3094.453 408.6886 408.6886 136.2692 895.2621

Total Flowkg/sec 0.7718001 0.6153161 1.30237 1.422462 1.30237 1.30237 1.458854 0.156484 0.156484 0.0364355 0.3270487

Total Flowl/min 1.03E+05 41551.17 1.92E+05 2.07E+05 2.18E+05 87946.63 82630.37 13381.05 16998.41 3018.199 63453.67

Temperature C 564.4932 159.1346 668.9406 668.9406 796.5607 159.1346 85.57567 166.6998 285.6063 33.58157 708.4053

Pressurepsia 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.7 16.7

Vapor Frac 1 1 1 1 1 1 1 1 1 1 1

Liquid Frac 0 0 0 0 0 0 0 0 0 0 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0

EnthalpyJ/kmol -5.48E+07 3.93E+06 1.97E+07 1.98E+07 2.40E+07 3.93E+06 -3.68E+07 -2.31E+08 -2.27E+08 -7.42E+07 -1.81E+08

EnthalpyJ/kg -1.95E+06 1.37E+05 6.90E+05 6.87E+05 8.38E+05 1.37E+05 -1.30E+06 -1.01E+07 -9.87E+06 -4.63E+06 -8.28E+06

EnthalpykW -1508.377 84.55483 899.1297 976.7658 1091.204 178.9676 -1897.779 -1574.707 -1544.779 -168.5477 -2707.818

Entropy J/kmol-K 33490.34 13507.56 37500.69 38445.78 41697.21 13507.56 7692.727 3717.582 12551.34 -80642.84 32340.35

Entropy J/kg-K 1195.195 472.441 1311.626 1332.591 1458.404 472.441 271.9576 161.8199 546.3378 -5026.743 1475.473

Density kmol/cum 0.0160379 0.0310768 0.0142598 0.0142598 0.0125585 0.0310768 0.0374493 0.0305423 0.0240427 0.0451491 0.0141089

Density kg/cum 0.4493953 0.8885181 0.4077025 0.4114015 0.3590622 0.8885181 1.059311 0.701667 0.5523483 0.7243172 0.309248

Average MW 28.02082 28.591 28.591 28.8504 28.591 28.591 28.28649 22.97358 22.97358 16.04276 21.91863

Liq Vol 60F l/min 78.83665 69.15808 146.3791 158.4393 146.3791 146.3791 156.0576 15.49824 15.49824 7.298276 34.23165

*** ALL PHASES ***

TDEWC 58.31881 -191.3545 -191.3545 -190.1721 -191.3545 -191.3545 45.50493 80.98132 80.98132 -159.9087 81.22483

Substream: $TOTAL 

Total Flowkg/sec 0.7718001 0.6153161 1.30237 1.422462 1.30237 1.30237 1.458854 0.156484 0.156484 0.0364355 0.3270487

EnthalpykW -1508.377 84.55483 899.1297 976.7658 1091.204 178.9676 -1897.779 -1574.707 -1544.779 -168.5477 -2707.818
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Table 6 (cont.)

FUEL-MIX FUELIN H2HP H2LP H2RCVRY O2FLUX PSA-BYP PSA-HP PSA-IN RECHP1 RECLP

Mole Flow mol/min 

CH4 136.2724 136.2692 0 0 1.72E-03 0 1.64E-03 1.63E-09 1.64E-09 3.20E-03 3.20E-03

N2 0 0 0 0 0 0 0 0 0 0 0

CO 56.13707 0 0 0 30.22766 0 2.187674 2.18E-06 2.19E-06 56.13707 56.13707

CO2 196.8595 0 0 0 106.0013 0 134.0413 1.31E-04 1.34E-04 196.8595 196.8595

H2 119.6945 0 7.86E-05 7.86E-05 64.4509 0 92.49114 9.25E-05 9.25E-05 119.6945 119.6945

H2O 386.2987 0 0 0 208.0071 0 179.9667 7.70E-07 1.80E-04 386.2987 386.2987

O2 3.14E-15 0 0 0 1.69E-15 225.1822 1.11E-34 1.11E-40 1.11E-40 3.14E-15 3.14E-15

C 4.27E-27 0 0 0 2.30E-27 0 8.98E-36 8.98E-42 8.98E-42 4.27E-27 4.27E-27

Mole Frac 

CH4 0.152215 1 0 0 4.21E-06 0 4.00E-06 7.19E-06 4.00E-06 4.21E-06 4.21E-06

N2 0 0 0 0 0 0 0 0 0 0 0

CO 0.0627046 0 0 0 0.0739625 0 5.35E-03 9.64E-03 5.35E-03 0.0739625 0.0739625

CO2 0.2198904 0 0 0 0.2593694 0 0.3279791 0.5786211 0.3279791 0.2593694 0.2593694

H2 0.1336977 0 1 1 0.1577017 0 0.2263121 0.4083304 0.2263121 0.1577017 0.1577017

H2O 0.4314923 0 0 0 0.5089622 0 0.4403519 3.40E-03 0.4403519 0.5089622 0.5089622

O2 3.50E-18 0 0 0 4.13E-18 1 2.72E-37 4.90E-37 2.72E-37 4.13E-18 4.13E-18

C 4.77E-30 0 0 0 5.63E-30 0 2.20E-38 3.96E-38 2.20E-38 5.63E-30 5.63E-30

Total Flowmol/min 895.2621 136.2692 7.86E-05 7.86E-05 408.6887 225.1822 408.6885 2.26E-04 4.09E-04 758.993 758.993

Total Flowkg/sec 0.3270487 0.0364355 2.64E-09 2.64E-09 0.1564841 0.1200927 0.1564839 1.00E-07 1.56E-07 0.2906132 0.2906132

Total Flowl/min 45026.36 3277.015 4.90E-06 1.74E-04 23490.84 15791.38 13381.05 5.03E-04 0.013381 42734.71 43625.82

Temperature C 423.356 20 50 30 499.0194 668.9406 166.6999 30 166.6999 506.5924 499.0194

Pressurepsia 16.7 14.7 6250 164.6959 16.2 16.2 16.2 164.6959 16.2 16.7 16.2

Vapor Frac 1 1 1 1 1 1 1 1 1 1 1

Liquid Frac 0 0 0 0 0 0 0 0 0 0 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0

EnthalpyJ/kmol -1.94E+08 -7.47E+07 7.21E+05 1.44E+05 -2.16E+08 2.07E+07 -2.31E+08 -2.29E+08 -2.31E+08 -2.16E+08 -2.16E+08

EnthalpyJ/kg -8.85E+06 -4.66E+06 3.58E+05 71411.16 -9.40E+06 6.46E+05 -1.01E+07 -8.62E+06 -1.01E+07 -9.38E+06 -9.40E+06

EnthalpykW -2895.918 -169.6504 9.45E-07 1.89E-07 -1470.633 77.63496 -1574.706 -8.66E-04 -1.57E-03 -2727.37 -2731.18

Entropy J/kmol-K 17216.78 -81201.15 -48001.69 -19612.99 28247.81 35534.22 3717.578 -10945.15 3717.578 28382.72 28247.81

Entropy J/kg-K 785.4859 -5061.545 -23811.78 -9729.247 1229.578 1110.486 161.8197 -411.1691 161.8197 1235.45 1229.578

Density kmol/cum 0.019883 0.0415833 16.03864 0.4505231 0.0173977 0.0142598 0.0305423 0.4505231 0.0305423 0.0177605 0.0173977

Density kg/cum 0.4358097 0.6671112 32.33198 0.9082005 0.3996897 0.4562971 0.7016667 11.99274 0.7016667 0.4080241 0.3996897

Average MW 21.91863 16.04276 2.01588 2.01588 22.97359 31.9988 22.97358 26.61958 22.97358 22.97359 22.97359

Liq Vol 60F l/min 34.23165 7.298276 4.21E-06 4.21E-06 14.50259 12.06026 15.49823 1.21E-05 1.55E-05 26.93338 26.93338

*** ALL PHASES ***

TDEWC 81.22483 -161.4806 -240.9781 84.61444 -182.0033 80.98133 30.00004 80.98133 85.39109 84.61444

Substream: $TOTAL 

Total Flowkg/sec 0.3270487 0.0364355 2.64E-09 2.64E-09 0.1564841 0.1200927 0.1564839 1.00E-07 1.56E-07 0.2906132 0.2906132

EnthalpykW -2895.918 -169.6504 9.45E-07 1.89E-07 -1470.633 77.63496 -1574.706 -8.66E-04 -1.57E-03 -2727.37 -2731.18
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Table 6 (cont.)

REFBYP REFOUT WATOUT1 WTR01 WTR02 WTR03 WTR04

Mole Flow mol/min 

CH4 4.92E-05 109.0179 0 0 0 0 0

N2 0 0 0 0 0 0 0

CO 0.8636537 51.71445 3.76E-09 0 0 0 0

CO2 3.028631 228.5366 2.99E-06 0 0 0 0

H2 1.841467 233.135 1.06E-08 0 0 0 0

H2O 5.943101 327.3671 1.79E-04 20779.94 20779.94 20779.94 20779.94

O2 4.82E-17 2.43E-22 0 0 0 0 0

C 6.57E-29 2.11E-34 0 0 0 0 0

Mole Frac 

CH4 4.21E-06 0.1147833 0 0 0 0 0

N2 0 0 0 0 0 0 0

CO 0.0739625 0.0544493 2.06E-05 0 0 0 0

CO2 0.2593694 0.2406228 0.0164234 0 0 0 0

H2 0.1577017 0.2454644 5.79E-05 0 0 0 0

H2O 0.5089622 0.3446801 0.9834979 1 1 1 1

O2 4.13E-18 2.56E-25 0 0 0 0 0

C 5.63E-30 2.22E-37 0 0 0 0 0

Total Flowmol/min 11.6769 949.7711 1.82E-04 20779.94 20779.94 20779.94 20779.94

Total Flowkg/sec 4.47E-03 0.3270487 5.60E-08 6.239274 6.239274 6.239274 6.239274

Total Flowl/min 875.9112 58015.06 1.23E-05 390.1488 397.9672 398.5983 390.1488

Temperature C 734.5684 572.7713 29.89082 60 78.55294 80 60

Pressurepsia 16.2 16.7 16.2 30 30 30 30

Vapor Frac 1 1 2.17E-03 0 0 0 0

Liquid Frac 0 0 0.997833 1 1 1 1

Solid Frac 0 0 0 0 0 0 0

EnthalpyJ/kmol -2.06E+08 -1.72E+08 -2.87E+08 -2.83E+08 -2.82E+08 -2.82E+08 -2.83E+08

EnthalpyJ/kg -8.98E+06 -8.31E+06 -1.56E+07 -1.57E+07 -1.56E+07 -1.56E+07 -1.57E+07

EnthalpykW -40.13741 -2717.817 -8.72E-04 -98073.96 -97590.14 -97551.57 -98073.96

Entropy J/kmol-K 39156.42 31087.66 -1.59E+05 -1.55E+05 -1.51E+05 -1.50E+05 -1.55E+05

Entropy J/kg-K 1704.411 1504.677 -8612.076 -8592.745 -8367.796 -8350.408 -8592.745

Density kmol/cum 0.0133311 0.0163711 14.85758 53.26158 52.2152 52.13253 53.26158

Density kg/cum 0.3062643 0.3382385 273.9958 959.5222 940.6715 939.1821 959.5222

Average MW 22.97359 20.66069 18.44148 18.01528 18.01528 18.01528 18.01528

Liq Vol 60F l/min 0.4143628 39.24356 3.40E-06 375.0779 375.0779 375.0779 375.0779

*** ALL PHASES ***

TDEWC 84.61444 75.73295 102.3016 121.3395 121.3395 121.3395 121.3395

Substream: $TOTAL 

Total Flowkg/sec 4.47E-03 0.3270487 5.60E-08 6.239274 6.239274 6.239274 6.239274

EnthalpykW -40.13741 -2717.817 -8.72E-04 -98073.96 -97590.14 -97551.57 -98073.96
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Table 7. SOFC-CHHP stream table

AIR-1 AIR-WRM AIRFLBYP AIRIN AN-LOWH2 ANODH2-1 ANODH2-2 ANODIN ANODOUT1 ANODOUT2 ANODOUT3

Mole Flow mol/min 

CH4 0 0 2.69E-04 0 1.63E-03 1.64E-03 1.64E-03 109.0179 4.92E-03 4.92E-03 4.92E-03

N2 2337.046 2337.046 0 2337.046 0 0 0 0 0 0 0

CO 0 0 4.723909 0 2.183914 2.187676 2.187676 51.71445 86.36537 86.36537 86.36475

CO2 0 0 16.56564 0 131.049 134.0414 134.0414 228.5366 302.8631 302.8631 302.8609

H2 0 0 10.07224 0 13.8721 92.49124 92.49124 233.135 184.1467 184.1467 184.1454

H2O 0 0 32.50686 0 0.7697566 179.9669 179.9669 327.3671 594.3101 594.3101 594.3059

O2 621.2402 621.2402 2.64E-16 621.2402 0 1.11E-34 1.11E-34 2.43E-22 4.82E-15 4.82E-15 4.82E-15

C 0 0 3.59E-28 0 0 8.98E-36 8.98E-36 2.11E-34 6.57E-27 6.57E-27 6.57E-27

Mole Frac 

CH4 0 0 4.21E-06 0 1.10E-05 4.00E-06 4.00E-06 0.1147833 4.21E-06 4.21E-06 4.21E-06

N2 0.79 0.79 0 0.79 0 0 0 0 0 0 0

CO 0 0 0.0739625 0 0.0147685 5.35E-03 5.35E-03 0.0544493 0.0739625 0.0739625 0.0739625

CO2 0 0 0.2593694 0 0.8862063 0.3279791 0.3279791 0.2406228 0.2593694 0.2593694 0.2593694

H2 0 0 0.1577017 0 0.0938087 0.2263121 0.2263121 0.2454644 0.1577017 0.1577017 0.1577017

H2O 0 0 0.5089622 0 5.21E-03 0.4403519 0.4403519 0.3446801 0.5089622 0.5089622 0.5089622

O2 0.21 0.21 4.13E-18 0.21 0 2.72E-37 2.72E-37 2.56E-25 4.13E-18 4.13E-18 4.13E-18

C 0 0 5.63E-30 0 0 2.20E-38 2.20E-38 2.22E-37 5.63E-30 5.63E-30 5.63E-30

Total Flowmol/min 2958.286 2958.286 63.86891 2958.286 147.8764 408.6889 408.6889 949.7711 1167.69 1167.69 1167.682

Total Flowkg/sec 1.422462 1.422462 0.0244549 1.422462 0.0978411 0.1564841 0.1564841 0.3270487 0.4471005 0.4471005 0.4470974

Total Flowl/min 67342.52 75521.75 3671.093 71141.18 327.4782 18015.12 13351.47 63466.39 93278.45 87591.12 67116.67

Temperature C 32.66295 69.80611 499.0194 20 30 319.0265 165.7274 652.2575 800 734.5684 499.0194

Pressurepsia 16.2 16.2 16.2 14.7 164.6959 16.2 16.2 16.7 16.2 16.2 16.2

Vapor Frac 1 1 1 1 0.9976798 1 1 1 1 1 1

Liquid Frac 0 0 0 0 2.32E-03 0 0 0 0 0 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0

EnthalpyJ/kmol 2.24E+05 1.31E+06 -2.16E+08 -1.46E+05 -3.52E+08 -2.26E+08 -2.31E+08 -1.68E+08 -2.03E+08 -2.06E+08 -2.16E+08

EnthalpyJ/kg 7749.924 45364.87 -9.40E+06 -5055.209 -8.86E+06 -9.82E+06 -1.01E+07 -8.14E+06 -8.86E+06 -8.98E+06 -9.40E+06

EnthalpykW 11.02398 64.52982 -229.8271 -7.190845 -866.3803 -1536.139 -1574.946 -2663.438 -3959.363 -4013.741 -4201.81

Entropy J/kmol-K 4203.506 7552.521 28247.81 3777.6 -12647.01 14756.25 3637.646 34968.23 41842.66 39156.42 28247.81

Entropy J/kg-K 145.7001 261.7822 1229.578 130.9375 -318.5765 642.3141 158.3404 1692.501 1821.338 1704.411 1229.578

Density kmol/cum 0.0439289 0.0391713 0.0173977 0.0415833 0.451561 0.0226858 0.03061 0.0149649 0.0125183 0.0133311 0.0173977

Density kg/cum 1.267368 1.130108 0.3996897 1.199695 17.92629 0.5211757 0.7032215 0.3091861 0.2875909 0.3062643 0.3996897

Average MW 28.8504 28.8504 22.97359 28.8504 39.69849 22.97358 22.97358 20.66069 22.97359 22.97359 22.97359

Liq Vol 60F l/min 158.4393 158.4393 2.266431 158.4393 7.892601 15.49825 15.49825 39.24356 41.43628 41.43628 41.43598

*** ALL PHASES ***

TDEWC -190.1721 -190.1721 84.61444 -191.015 38.16618 80.98133 80.98133 75.73295 84.61444 84.61444 84.61444

Substream: $TOTAL 

Total Flowkg/sec 1.422462 1.422462 0.0244549 1.422462 0.0978411 0.1564841 0.1564841 0.3270487 0.4471005 0.4471005 0.4470974

EnthalpykW 11.02398 64.52982 -229.8271 -7.190845 -866.3803 -1536.139 -1574.946 -2663.438 -3959.363 -4013.741 -4201.81
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Table 7 (cont.)

ANODOUT4 ANOUT1A ANOUT1B ANOUT2A ANOUT2B ANOUT3A ANOUT3B ANOUTBYP BRNBYPAS BRNOUT-1 BRNOUT-2

Mole Flow mol/min 

CH4 1.72E-03 1.97E-03 1.97E-03 4.87E-03 4.87E-03 1.45E-03 1.45E-03 2.95E-03 0 0 0

N2 0 0 0 0 0 0 0 0 2276.466 60.58065 2337.046

CO 30.22766 34.54615 34.54615 85.5011 85.5011 25.50376 25.50376 51.81922 0 0 0

CO2 106.0013 121.1452 121.1452 299.8323 299.8323 89.43569 89.43569 181.7178 0 133.2345 133.2345

H2 64.4509 73.6587 73.6587 182.304 182.304 54.37867 54.37867 110.488 0 0 0

H2O 208.0071 237.7241 237.7241 588.3628 588.3628 175.5002 175.5002 356.5861 0 14.64512 14.64512

O2 1.69E-15 1.93E-15 1.93E-15 4.78E-15 4.78E-15 1.42E-15 1.42E-15 2.89E-15 385.7914 2.235304 388.0267

C 2.30E-27 2.63E-27 2.63E-27 6.50E-27 6.50E-27 1.94E-27 1.94E-27 3.94E-27 0 0 0

Mole Frac 

CH4 4.21E-06 4.21E-06 4.21E-06 4.21E-06 4.21E-06 4.21E-06 4.21E-06 4.21E-06 0 0 0

N2 0 0 0 0 0 0 0 0 0.8550886 0.2875269 0.813465

CO 0.0739625 0.0739625 0.0739625 0.0739625 0.0739625 0.0739625 0.0739625 0.0739625 0 0 0

CO2 0.2593694 0.2593694 0.2593694 0.2593694 0.2593694 0.2593694 0.2593694 0.2593694 0 0.6323555 0.0463754

H2 0.1577017 0.1577017 0.1577017 0.1577017 0.1577017 0.1577017 0.1577017 0.1577017 0 0 0

H2O 0.5089622 0.5089622 0.5089622 0.5089622 0.5089622 0.5089622 0.5089622 0.5089622 0 0.0695084 5.10E-03

O2 4.13E-18 4.13E-18 4.13E-18 4.13E-18 4.13E-18 4.13E-18 4.13E-18 4.13E-18 0.1449114 0.0106091 0.135062

C 5.63E-30 5.63E-30 5.63E-30 5.63E-30 5.63E-30 5.63E-30 5.63E-30 5.63E-30 0 0 0

Total Flowmol/min 408.6887 467.0761 467.0761 1156.005 1156.005 344.8198 344.8198 700.6141 2662.257 210.6956 2872.953

Total Flowkg/sec 0.1564841 0.1788402 0.1788402 0.4426264 0.4426264 0.1320291 0.1320291 0.2682603 1.26861 0.131601 1.400211

Total Flowl/min 17275.67 37311.38 31550.39 86714.59 66233.67 19819.74 13565.46 55967.07 85666.89 13565.77 97726.38

Temperature C 294.7202 800 634.3024 734.5684 496.5577 499.0194 255.3551 800 159.1346 591.8091 183.8225

Pressurepsia 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2 16.2

Vapor Frac 1 1 1 1 1 1 1 1 1 1 1

Liquid Frac 0 0 0 0 0 0 0 0 0 0 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0

EnthalpyJ/kmol -2.24E+08 -2.03E+08 -2.10E+08 -2.06E+08 -2.16E+08 -2.16E+08 -2.25E+08 -2.03E+08 3.93E+06 -2.43E+08 -1.47E+07

EnthalpyJ/kg -9.74E+06 -8.86E+06 -9.16E+06 -8.98E+06 -9.40E+06 -9.40E+06 -9.80E+06 -8.86E+06 1.37E+05 -6.47E+06 -5.04E+05

EnthalpykW -1524.139 -1583.745 -1638.124 -3973.572 -4161.672 -1240.806 -1294.312 -2375.618 174.3284 -851.7898 -705.6283

Entropy J/kmol-K 16451.17 41842.66 34776.55 39156.42 28121.18 28247.81 13796.08 41842.66 13507.56 47648.84 16897.85

Entropy J/kg-K 716.0907 1821.338 1513.762 1704.411 1224.066 1229.578 600.5191 1821.338 472.441 1271.444 577.8501

Density kmol/cum 0.0236568 0.0125183 0.0148041 0.0133311 0.0174534 0.0173977 0.0254189 0.0125183 0.0310768 0.0155314 0.0293979

Density kg/cum 0.5434836 0.2875909 0.3401039 0.3062643 0.400968 0.3996897 0.5839644 0.2875909 0.8885181 0.582058 0.8596722

Average MW 22.97359 22.97359 22.97359 22.97359 22.97359 22.97359 22.97359 22.97359 28.591 37.47616 29.24262

Liq Vol 60F l/min 14.50259 16.57451 16.57451 41.02162 41.02162 12.23616 12.23616 24.86176 142.5846 10.76438 153.349

*** ALL PHASES ***

TDEWC 84.61444 84.61444 84.61444 84.61444 84.61444 84.61444 84.61444 84.61444 -191.3545 41.09008 -0.9057125

Substream: $TOTAL 

Total Flowkg/sec 0.1564841 0.1788402 0.1788402 0.4426264 0.4426264 0.1320291 0.1320291 0.2682603 1.26861 0.131601 1.400211

EnthalpykW -1524.139 -1583.745 -1638.124 -3973.572 -4161.672 -1240.806 -1294.312 -2375.618 174.3284 -851.7898 -705.6283
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Table 7 (cont.)

BRNOUT1B BURN-IN CAT-COLD CAT-IN CAT-OUT COMBAIR EXHAUST FBRNIN1 FBRNIN2 FUEL-1 FUEL-HOT

Mole Flow mol/min 

CH4 0 0 0 0 0 0 0 1.63E-03 1.63E-03 136.2692 136.2724

N2 60.58065 60.58065 2337.046 2337.046 2337.046 2337.046 2337.046 0 0 0 0

CO 0 0 0 0 0 0 0 2.183914 2.183914 0 56.13707

CO2 133.2345 0 0 0 0 0 133.2345 131.049 131.049 0 196.8595

H2 0 0 0 0 0 0 0 13.8721 13.8721 0 119.6945

H2O 14.64512 0 0 0 0 0 14.64512 0.7697566 0.7697566 0 386.2987

O2 2.235304 10.26657 396.0579 621.2402 396.0579 396.0579 388.0267 0 0 0 3.14E-15

C 0 0 0 0 0 0 0 0 0 0 4.27E-27

Mole Frac 

CH4 0 0 0 0 0 0 0 1.10E-05 1.10E-05 1 0.152215

N2 0.2875269 0.8550886 0.8550886 0.79 0.8550886 0.8550886 0.813465 0 0 0 0

CO 0 0 0 0 0 0 0 0.0147685 0.0147685 0 0.0627046

CO2 0.6323555 0 0 0 0 0 0.0463754 0.8862063 0.8862063 0 0.2198904

H2 0 0 0 0 0 0 0 0.0938087 0.0938087 0 0.1336977

H2O 0.0695084 0 0 0 0 0 5.10E-03 5.21E-03 5.21E-03 0 0.4314923

O2 0.0106091 0.1449114 0.1449114 0.21 0.1449114 0.1449114 0.135062 0 0 0 3.50E-18

C 0 0 0 0 0 0 0 0 0 0 4.77E-30

Total Flowmol/min 210.6956 70.84722 2733.104 2958.286 2733.104 2733.104 2872.953 147.8764 147.8764 136.2692 895.2621

Total Flowkg/sec 0.131601 0.0337598 1.30237 1.422462 1.30237 1.30237 1.400211 0.0978411 0.0978411 0.0364355 0.3270487

Total Flowl/min 10708.8 2279.743 1.92E+05 2.07E+05 2.18E+05 87946.63 73052.93 327.4782 626.3595 3018.199 63453.67

Temperature C 409.6477 159.1346 668.9406 668.9406 796.5607 159.1346 68.44846 30 305.3448 33.58157 708.4053

Pressurepsia 16.2 16.2 16.2 16.2 16.2 16.2 16.2 164.6959 164.6959 16.7 16.7

Vapor Frac 1 1 1 1 1 1 1 0.9976798 1 1 1

Liquid Frac 0 0 0 0 0 0 0 2.32E-03 0 0 0

Solid Frac 0 0 0 0 0 0 0 0 0 0 0

EnthalpyJ/kmol -2.51E+08 3.93E+06 1.97E+07 1.98E+07 2.40E+07 3.93E+06 -1.82E+07 -3.52E+08 -3.40E+08 -7.42E+07 -1.81E+08

EnthalpyJ/kg -6.69E+06 1.37E+05 6.90E+05 6.87E+05 8.38E+05 1.37E+05 -6.22E+05 -8.86E+06 -8.57E+06 -4.63E+06 -8.28E+06

EnthalpykW -879.9568 4.639179 899.1297 976.7658 1091.204 178.9676 -871.1925 -866.3803 -838.203 -168.5477 -2707.818

Entropy J/kmol-K 37244.07 13507.56 37500.69 38445.78 41697.21 13507.56 8180.888 -12647.01 13982.57 -80642.84 32340.35

Entropy J/kg-K 993.8069 472.441 1311.626 1332.591 1458.404 472.441 279.7591 -318.5765 352.2192 -5026.743 1475.473

Density kmol/cum 0.019675 0.0310768 0.0142598 0.0142598 0.0125585 0.0310768 0.039327 0.451561 0.2360887 0.0451491 0.0141089

Density kg/cum 0.7373434 0.8885181 0.4077025 0.4114015 0.3590622 0.8885181 1.150024 17.92629 9.372365 0.7243172 0.309248

Average MW 37.47616 28.591 28.591 28.8504 28.591 28.591 29.24262 39.69849 39.69849 16.04276 21.91863

Liq Vol 60F l/min 10.76438 3.794421 146.3791 158.4393 146.3791 146.3791 153.349 7.892601 7.892601 7.298276 34.23165

*** ALL PHASES ***

TDEWC 41.09008 -191.3545 -191.3545 -190.1721 -191.3545 -191.3545 -0.9057125 38.16618 38.16618 -159.9087 81.22483

Substream: $TOTAL 

Total Flowkg/sec 0.131601 0.0337598 1.30237 1.422462 1.30237 1.30237 1.400211 0.0978411 0.0978411 0.0364355 0.3270487

EnthalpykW -879.9568 4.639179 899.1297 976.7658 1091.204 178.9676 -871.1925 -866.3803 -838.203 -168.5477 -2707.818
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Table 7 (cont.)

FUEL-MIX FUELIN H2HP H2LP H2RCVRY O2FLUX PSA-BYP PSA-HP PSA-IN RECHP1 RECLP

Mole Flow mol/min 

CH4 136.2724 136.2692 0 0 1.72E-03 0 0 1.63E-03 1.64E-03 3.20E-03 3.20E-03

N2 0 0 0 0 0 0 0 0 0 0 0

CO 56.13707 0 0 0 30.22766 0 0 2.183914 2.187676 56.13707 56.13707

CO2 196.8595 0 0 0 106.0013 0 0 131.049 134.0414 196.8595 196.8595

H2 119.6945 0 78.60858 78.60858 64.4509 0 0 92.48068 92.49124 119.6945 119.6945

H2O 386.2987 0 0 0 208.0071 0 0 0.7697566 179.9669 386.2987 386.2987

O2 3.14E-15 0 0 0 1.69E-15 225.1822 0 1.11E-34 1.11E-34 3.14E-15 3.14E-15

C 4.27E-27 0 0 0 2.30E-27 0 0 8.98E-36 8.98E-36 4.27E-27 4.27E-27

Mole Frac 

CH4 0.152215 1 0 0 4.21E-06 0 0 7.19E-06 4.00E-06 4.21E-06 4.21E-06

N2 0 0 0 0 0 0 0 0 0 0 0

CO 0.0627046 0 0 0 0.0739625 0 0 9.64E-03 5.35E-03 0.0739625 0.0739625

CO2 0.2198904 0 0 0 0.2593694 0 0 0.5786211 0.3279791 0.2593694 0.2593694

H2 0.1336977 0 1 1 0.1577017 0 0 0.4083304 0.2263121 0.1577017 0.1577017

H2O 0.4314923 0 0 0 0.5089622 0 0 3.40E-03 0.4403519 0.5089622 0.5089622

O2 3.50E-18 0 0 0 4.13E-18 1 0 4.90E-37 2.72E-37 4.13E-18 4.13E-18

C 4.77E-30 0 0 0 5.63E-30 0 0 3.96E-38 2.20E-38 5.63E-30 5.63E-30

Total Flowmol/min 895.2621 136.2692 78.60858 78.60858 408.6887 225.1822 0 226.485 408.6889 758.993 758.993

Total Flowkg/sec 0.3270487 0.0364355 2.64E-03 2.64E-03 0.1564841 0.1200927 0 0.1004823 0.1564841 0.2906132 0.2906132

Total Flowl/min 45026.36 3277.015 4.901199 174.4829 23490.84 15791.38 0 502.7155 13351.47 42734.71 43625.82

Temperature C 423.356 20 50 30 499.0194 668.9406 30 165.7274 506.5924 499.0194

Pressurepsia 16.7 14.7 6250 164.6959 16.2 16.2 164.6959 16.2 16.7 16.2

Vapor Frac 1 1 1 1 1 1 1 1 1 1

Liquid Frac 0 0 0 0 0 0 0 0 0 0

Solid Frac 0 0 0 0 0 0 0 0 0 0

EnthalpyJ/kmol -1.94E+08 -7.47E+07 7.21E+05 1.44E+05 -2.16E+08 2.07E+07 -2.29E+08 -2.31E+08 -2.16E+08 -2.16E+08

EnthalpyJ/kg -8.85E+06 -4.66E+06 3.58E+05 71411.16 -9.40E+06 6.46E+05 -8.62E+06 -1.01E+07 -9.38E+06 -9.40E+06

EnthalpykW -2895.918 -169.6504 0.9449698 0.1886034 -1470.633 77.63496 -865.9747 -1574.946 -2727.37 -2731.18

Entropy J/kmol-K 17216.78 -81201.15 -48001.69 -19612.99 28247.81 35534.22 -10945.15 3637.646 28382.72 28247.81

Entropy J/kg-K 785.4859 -5061.545 -23811.78 -9729.247 1229.578 1110.486 -411.1691 158.3404 1235.45 1229.578

Density kmol/cum 0.019883 0.0415833 16.03864 0.4505231 0.0173977 0.0142598 0.4505231 0.03061 0.0177605 0.0173977

Density kg/cum 0.4358097 0.6671112 32.33198 0.9082005 0.3996897 0.4562971 11.99274 0.7032215 0.4080241 0.3996897

Average MW 21.91863 16.04276 2.01588 2.01588 22.97359 31.9988 26.61958 22.97358 22.97359 22.97359

Liq Vol 60F l/min 34.23165 7.298276 4.210103 4.210103 14.50259 12.06026 0 12.1027 15.49825 26.93338 26.93338

*** ALL PHASES ***

TDEWC 81.22483 -161.4806 -240.9781 84.61444 -182.0033 30.00004 80.98133 85.39109 84.61444

Substream: $TOTAL 

Total Flowkg/sec 0.3270487 0.0364355 2.64E-03 2.64E-03 0.1564841 0.1200927 0 0.1004823 0.1564841 0.2906132 0.2906132

EnthalpykW -2895.918 -169.6504 0.9449698 0.1886034 -1470.633 77.63496 0 -865.9747 -1574.946 -2727.37 -2731.18
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Table 7 (cont.)

REFBYP REFOUT WATOUT1 WTR01 WTR02 WTR03 WTR04

Mole Flow mol/min 

CH4 4.92E-05 109.0179 6.86E-06 0 0 0 0

N2 0 0 0 0 0 0 0

CO 0.8636537 51.71445 3.76E-03 0 0 0 0

CO2 3.028631 228.5366 2.992424 0 0 0 0

H2 1.841467 233.135 0.010551 0 0 0 0

H2O 5.943101 327.3671 179.1972 8129.539 8129.539 8129.539 8129.539

O2 4.82E-17 2.43E-22 0 0 0 0 0

C 6.57E-29 2.11E-34 0 0 0 0 0

Mole Frac 

CH4 4.21E-06 0.1147833 3.77E-08 0 0 0 0

N2 0 0 0 0 0 0 0

CO 0.0739625 0.0544493 2.06E-05 0 0 0 0

CO2 0.2593694 0.2406228 0.0164234 0 0 0 0

H2 0.1577017 0.2454644 5.79E-05 0 0 0 0

H2O 0.5089622 0.3446801 0.9834979 1 1 1 1

O2 4.13E-18 2.56E-25 0 0 0 0 0

C 5.63E-30 2.22E-37 0 0 0 0 0

Total Flowmol/min 11.6769 949.7711 182.2039 8129.539 8129.539 8129.539 8129.539

Total Flowkg/sec 4.47E-03 0.3270487 0.0560018 2.440932 2.440932 2.440932 2.440932

Total Flowl/min 875.9112 58015.06 12.26386 152.6342 155.3058 155.9399 152.6342

Temperature C 734.5684 572.7713 29.89085 60 76.26915 80.00043 60

Pressurepsia 16.2 16.7 16.2 30 30 30 30

Vapor Frac 1 1 2.17E-03 0 0 0 0

Liquid Frac 0 0 0.9978329 1 1 1 1

Solid Frac 0 0 0 0 0 0 0

EnthalpyJ/kmol -2.06E+08 -1.72E+08 -2.87E+08 -2.83E+08 -2.82E+08 -2.82E+08 -2.83E+08

EnthalpyJ/kg -8.98E+06 -8.31E+06 -1.56E+07 -1.57E+07 -1.57E+07 -1.56E+07 -1.57E+07

EnthalpykW -40.13741 -2717.817 -871.9243 -38368.55 -38202.98 -38164.17 -38368.55

Entropy J/kmol-K 39156.42 31087.66 -1.59E+05 -1.55E+05 -1.51E+05 -1.50E+05 -1.55E+05

Entropy J/kg-K 1704.411 1504.677 -8612.076 -8592.745 -8395.281 -8350.403 -8592.745

Density kmol/cum 0.0133311 0.0163711 14.85698 53.26158 52.34536 52.1325 53.26158

Density kg/cum 0.3062643 0.3382385 273.9847 959.5222 943.0163 939.1816 959.5222

Average MW 22.97359 20.66069 18.44148 18.01528 18.01528 18.01528 18.01528

Liq Vol 60F l/min 0.4143628 39.24356 3.395543 146.7382 146.7382 146.7382 146.7382

*** ALL PHASES ***

TDEWC 84.61444 75.73295 102.3016 121.3395 121.3395 121.3395 121.3395

Substream: $TOTAL 

Total Flowkg/sec 4.47E-03 0.3270487 0.0560018 2.440932 2.440932 2.440932 2.440932

EnthalpykW -40.13741 -2717.817 -871.9243 -38368.55 -38202.98 -38164.17 -38368.55
79 

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3 FCPower Model Case Studies

3.1 Molten Carbonate Fuel Cell Case Study Description

The case study models installation of a fuel cell CHHP system at a large hotel in Los Angeles.

The system is assumed to start operation in 2013 and will operate for 20 years. Dollar amounts 

are shown in 2007 dollars. The FCPower Model escalates these using the inflation rate (1.9% for 

this analysis) and performs all calculations in current dollars. The system is assumed to be a 

combined heat, hydrogen, and power system. The fuel cell is sized to meet the average AC 

demand of the hotel. Electricity and heat from the fuel cell are used at the hotel, and hydrogen 

produced by the system is piped to a nearby fueling station. Additional electricity needed for 

high-demand periods is purchased from the utility, and excess electricity produced by the fuel 

cell during periods of especially low demand is sold back to the utility under a net-metering 

agreement. Hydrogen CSD are assumed to closely resemble the CSD portion for standalone 

forecourt SMR hydrogen production at a comparable hydrogen production rate. The business is 

assumed to take advantage of the federal fuel cell tax credit. Note that the cost values used in this 

case study are for illustration purposes only and are not validated or endorsed by DOE. 

An MCFC system nominally includes a fuel processor integrated with the MCFCs and powerconditioning equipment. A standard CHP fuel cell system used in CHP applications also includes 

a water purification system, nitrogen-purging equipment, piping, valves, plumbing, and heat 

exchanger [3]. Owing to the high operating temperature, internal fuel reforming is possible; 

however, systems generally include at least some form of external fuel reformer as well [4,5]. 

The MCFC operates at about 650°C, which necessitates special design considerations owing to 

the high temperature and potential for corrosion.

The CHHP application modeled includes additional equipment for integrating the hydrogen coproduction with a standard CHP application. In addition to the fuel cell plant—which includes a 

fuel-reforming system, fuel cell stacks, and power-conditioning equipment—a shift reactor 

converts additional CO to hydrogen, and a PSA unit extracts hydrogen from the fuel cell exhaust 

stream. A CSD unit is installed for vehicle refueling. The CSD costs do not include costs for a 

convenience store or building. 

The CHHP power model includes several additional components that can be included within the 

model analysis. These include a burner for additional heat, an electrolyzer for additional 

hydrogen production, and an additional, usually smaller fuel cell for meeting peak electricity 

demand. Hydrogen storage can be used for electricity or vehicle fueling. However, it is assumed 

that the fuel cell system will tie into existing building electricity, heating, cooling, and domestic 

hot water production. Equipment such as additional thermal storage is not used; existing thermal 

water storage is used instead. 

3.1.1 Financial Inputs

Fuel Cell System

MCFC systems are slightly behind PAFC systems in market entry; however, estimates of their 

potential for cost reduction at high volume are favorable. Costs were collected from a number of 

sources, and references are shown in brackets for particular estimates in Figure 49 [4,6–9]. The 
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capital costs in most cases are based on demonstration and pre-commercial estimates for lowvolume costs. Current costs assume commercial, low-volume productions, while high-volume 

costs are predictions for cost reduction at a production volume of at least 100 MW/yr.

Figure 49. Collected cost information for MCFC CHP plants

Equation 21. y = 15,908e-0.096x

Equation 22. x = year - 1992 

Equation 21 is the curve represented by current uninstalled low-volume production levels where 

y is the total uninstalled cost in $(2005)/kW and x is calculated as per Equation 22. It has an rsquared fit to the data of 0.95. The costs for the case study represent relatively high-volume 

production. The costs were adjusted from 2005 to 2007 dollars using the Chemical Engineering 

Plant Cost Index (CEPCI). A shift reactor and PSA system were added for hydrogen production 

and purification from the fuel cell. The shift reactor and PSA system were sized for the more 

dilute hydrogen stream from the MCFC. Direct uninstalled costs for the fuel cell plant including 

internal reforming were estimated to be $(2007)1,800/kW fuel cell rated AC power.2 The 

combined uninstalled cost of the shift reactor and fuel compressor was estimated to be 

$(2007)116/kW, and the uninstalled PSA cost was estimated to be $(2007)312/kW. Total CHHP 

system uninstalled direct capital cost is approximately $(2007)2,228/kW. Installation was 

 

2 Note that, although DOE supports fuel cell cost-estimation analysis, the $1,800/kW value is not derived from those 

efforts and should not be interpreted as a DOE-endorsed cost estimate. It is merely an example cost.

$0

$2,000

$4,000

$6,000

$8,000

$10,000

$12,000

1992 1997 2002 2007 2012

$(2005)/kW

Year

MCFC CHP Capital Costs

Current - installed

Current - uninstalled

High volume - installed

High volume - uninstalled

[6]

[4]

[4]

[6]

[9]

[7]

[4]

[8]

[4]

[4]

[9]
81 

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estimated to be 20% of the equipment cost for the fuel cell plant and PSA. Indirect costs are 25% 

of the installed equipment cost. Installation and indirect costs are approximately 

$(2007)1,085/kW for a total installed capital cost of the fuel cell and hydrogen purification 

system (not including CSD) of $3,313/kW.

Indirect capital costs are difficult to enumerate separately because researched costs are typically 

a combined cost. Additionally indirect costs for project contingency and permitting were 

generally not included in literature values for costs. The values used in the FCPower Model for 

project contingency and permitting (5% and 3% of installed equipment costs, respectively) are 

derived from previous H2A hydrogen production models [10]. The separation of direct and 

indirect capital cost was estimated and then split into 10% of installed equipment cost for site 

preparation and 7% for engineering and design. 

Operating and maintenance costs are as follows. Replacement costs are estimated to be 25% of 

the total fuel cell system capital cost every 10 years. Fixed maintenance and repairs were 

estimated at 2%, and variable unplanned replacement 1.5%, of direct fuel cell system capital cost 

yearly, both estimated using figures from an EPRI report [3]. 

Hydrogen Storage and Dispensing

The hydrogen CSD system operating assumptions and costs are derived from the H2A 

production forecourt model. It is assumed that the hydrogen produced by the system will be used 

in vehicles used on public streets. The scenario envisions a very small hydrogen demand in an 

emerging market. Therefore, the hydrogen is piped a short distance to an existing conventional 

fueling station where storage tanks for about 1 day of production and a single dispenser are 

located. 

3.1.2 Load Profile and Fuel Cell Specification

The hotel is assumed to have 176 rooms, a laundry, and a restaurant. The modeled building is six 

stories tall. The electricity and heat load profiles for the building are calculated using building 

simulation output from the NREL building systems model [12]. The building is assumed to be an 

existing building that was constructed using typical building techniques and materials. The 

electricity load includes electricity use for air conditioning, and the heat load is fuel demand for 

both space heating and hot water. Because the heating demand profile already accounts for the 

efficiency of the furnace or boiler, the efficiency of the burner for supplementary heat in the 

CHHP system is set at 100%.

The average building electrical demand is 229 kW with peaks in demand up to 471 kW and a 

minimum value of 71 kW. The fuel cell was assumed to be 200 kW, which is a commercially 

available size, with a maximum rated AC output just under the building’s average demand. 

3.1.3 Utilities

The fuel cell CHHP system is assumed to be grid parallel, with electrical connections that can be 

islanded from the grid during a power outage. Electricity demand that cannot be met by the fuel 

cell is provided by the grid. Both time-of-day and seasonal usage charges are assumed to apply. 

The base price for electricity purchased from the grid is $0.087/kWh in the startup year (2013), 

which is the EIA projected national average electricity rate for 2013. Peak rates and off-peak 

rates are 25% above and 10% below the base rate, respectively. Electricity can also be sold to the 
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grid if more electricity is produced by the system than is required by the hotel at that time. 

Electricity sold to the utility is assumed to be priced at the same price as electricity would cost if 

purchased during that hour (net metering). 

The fuel cell system and auxiliary space and hot water heating systems are assumed to be fueled 

with natural gas. The natural gas rate is assumed to be the projected average national commercial 

natural gas rate, which is $10.71/MMBtu in 2013. 

3.2 Molten Carbonate Fuel Cell Case Study Results

3.2.1 Baseline System

The FCPower Model calculates costs for supplying electricity and heat to the building and 

purchasing an equivalent amount of hydrogen for the refueling station in the absence of the fuel 

cell system. This baseline system assumes electricity purchased from the grid, heat for hot water 

and space heating supplied by a natural gas furnace or boiler, and hydrogen production using a 

small (forecourt) natural gas SMR. Electricity for the building is purchased using the same price 

schedule as is used for the CHHP supplementary electricity supply. Natural gas for heating and 

fueling the SMR unit is purchased at the same rate as fuel for the CHHP system. Yearly costs for 

energy for the baseline system are shown in Table 8. In a real-world application, a small-volume 

hydrogen station like this one likely would be part of an existing conventional fuel station 

(instead of being a standalone station as assumed here) and possibly supplied with off-sitegenerated hydrogen via truck, which might reduce the hydrogen cost below the $11.66/kg shown 

here.

Table 8. Baseline System Levelized Energy Costs (Prior to Installation of Fuel Cell)

Electricity (use and demand charges) $238,392/year

Commercial natural gas (for heat) $89,946/year

Hydrogen (from forecourt SMR, $11.66/kg) $347,674/year

Total baseline system energy cost per year $676,012/year

3.2.2 CHHP System Energy Supply

The MCFC CHHP system supplies a yearly total of 2,670 MWh of energy to the building in the 

form of electricity, heat, and hydrogen, in addition to 20 MWh of electricity that is sold to the 

utility. Of this, 1,300 MWh (49%) are in the form of electricity, 380 MWh (14%) are in the form 

of useful heat, and the remaining 994 MWh (29,819 kg, 37%) are in the form of hydrogen. The

total system efficiency is 76%. Table 9 shows the energy supplied by the fuel cell at full 

operation and supplementary electricity and heat purchased for the building. The analysis 

assumes that, during construction and startup (about 1 year), all of the electricity and heating fuel 

to supply the building will be purchased. 
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Table 9. MCFC System Building Energy Supply at Full Operation

System Energy to Building (kWh) Percent of Energy Type 

Supplied by the CHHP 

System

System net electricity to 

building 1,299,578 65

Fuel cell system heat 379,968 18

Hydrogen 993,857 100

Supplementary Building Electricity 

and Heat (kWh) 

Percent of Energy Type 

Supplied by 

Supplementary System

Supplementary electricity 813,392 35

Supplementary heat 1,831,935 82

Approximately 19% (307 MWh/year) of the fuel cell total electrical output of 1,626 MWh per 

year at full operation, is required for auxiliary power, primarily for the hydrogen purification 

system and compression of hydrogen to the dispensing pressure of 5,000 psi (350 bar). 

3.2.3 CHHP System Capital Costs and Credits

For the case study, it is assumed that a commercial entity (the hotel owner) purchases the fuel 

cell system and owns and operates the refueling station equipment but rents the land for the 

refueling station, which is co-located with a gasoline refueling station adjacent to the hotel. A 

300-ft pipeline connects the CHHP system to the storage tanks and compressors at the filling 

station. Equity financing, a 10% internal rate of return, and a 20-year life are assumed for the 

CHHP installation.

Table 10 shows the initial capital investment and federal tax credits taken for the installation.

Indirect capital investment (site preparation, engineering, contingency, and permitting) totals 

$177,472. 
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Table 10. MCFC System Initial Investment and Credits

Direct capital investment (reference year, (2007)$)

Major pieces/

systems of 

equipment 

Baseline 

installed 

costs ($)

(with 

indirect 

capital)

Depreciation 

type

Depreciation 

schedule 

(years)

Federal 

credit or 

incentive

Credit 

amount ($)

Total 

adjusted 

depreciable 

capital cost 

basis ($)a

MCFC System 

(including 

hydrogen 

purification)

530,092 MACRS 5 

Federal 

business 

energy tax 

credit

155,520 532,683

Auxiliary heater 170,754 MACRS 7 196,637

System 

integration and 

control

30,000 MACRS 7 34,547

Hydrogen 

compression, 

storage, and 

dispensing

439,969 MACRS 5 506,660

Total 1,170,815

($1,348,28) 155,520 1,270,527

a Total depreciation basis includes indirect capital costs. 

3.2.4 MCFC CHHP System Cash Flow

Figure 50 shows key expenditures and cash flow for the MCFC CHHP installation throughout its 

lifetime. Yearly replacement costs include an allowance of 1.5% of the initial depreciable capital 

investment for unplanned replacement of capital equipment as well as planned restacking of the 

fuel cell every 10 years. It is assumed that the compressors and dispensers will be replaced after 

10 years at 35% of the initial cost for the entire CSD system. A replacement cost of 25% of 

building system integration direct capital cost is also incurred after 10 years. Figure 50 indicates 

that the project will break even after approximately 7 years.

Figure 50. MCFC CHHP key yearly expenditures and revenue

($2,000,000)

($1,500,000)

($1,000,000)

($500,000)

$0 

$500,000 

$1,000,000 

$1,500,000 

$2,000,000 

-1 2 4 6 8 10 12 14 16 18 20 

Cash Flow ($/year)

Year of Operation

Cash Flow Analysis

Yearly Replacement Costs Initial Equity Capital Investment

Other Non-Depreciable Capital Costs Taxable Income

Portion of Initial Capital Financed with Debt Cumulative Cash Flow
85 

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3.2.5 Cost of Hydrogen and Total Annualized Costs

The FCPower Model solves for the levelized revenue for energy supplied by the CHHP system 

(electricity, heat, and hydrogen) that will result in a net present value (including inflation and an 

internal rate of return specified by the user) of zero for the project. The user may distribute the 

required revenue between the three energy streams in any way desired. However, the default 

distribution assumes that electricity supplied by the fuel cell is “sold” at the same price as would 

have been paid for grid electricity. Similarly, heat is assumed to be supplied at the same rate as 

purchased natural gas. The levelized profited cost of hydrogen is derived by difference. For this 

installation, the cost of hydrogen is $12.18/kg as dispensed. This is comparable to the cost of 

hydrogen supplied by a forecourt SMR unit ($11.66/kg) for the baseline system. Table 11 shows 

the total annualized costs for the MCFC CHHP system. 

Table 11. Total Annualized Costs for the MCFC CHHP Installation

Annualized costs

Capital costs $231,769 

Decommissioning costs $2,259 

Fixed O&M $132,061 

Feedstock costs $152,132 

Other raw material costs $0 

Byproduct credits –$1,755

Other variable costs (excluding supplementary 

electricity and heat)

$4,183 

Supplementary electricity $99,132 

Supplementary heat $83,367 

Total $703,148 

The total annualized cost for the CHHP system is slightly more than the energy costs for the 

baseline system of $676,012 shown in Table 8. This analysis indicates that the CHHP system 

could be a cost-effective alternative to conventional energy supply for the hotel. 

3.2.6 Sensitivity Analysis

Sensitivity analyses were performed for six key cost elements for the CHHP system: internal rate 

of return, federal business energy tax credit, reforming fuel cell cost, CSD cost, process fixed 

operating cost, and total depreciable capital cost. The results, presented in terms of levelized 

energy cost, are shown in Figure 51. 
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Figure 51. Sensitivity analysis for the MCFC CHHP system key costs (LCOE in $/kWh)

3.3 Phosphoric Acid Fuel Cell Case Study Description

The system is assumed to be a combined heat, hydrogen, and power system. The fuel cell is sized 

to meet the average AC demand. Hydrogen CSD are assumed to closely resemble the CSD 

portion for standalone forecourt SMR hydrogen production at a comparable hydrogen production 

rate. The business is assumed to take advantage of the federal fuel cell tax credit. 

A standard CHP fuel cell system used in CHP applications includes the PAFC(s), water 

purification system, nitrogen-purging equipment, power-conversion equipment, piping, valves, 

plumbing, and heat exchanger [3,13]. There may be a low-grade heat exchanger, delivering hot 

water in the 160°F range, and/or a high-grade heat exchanger for delivering water at 250°F 

depending on the installation thermal requirements [13]. A thermal storage unit might be used 

for following domestic hot water. The fuel cell will also have an air-cooling system (heat sink) to 

shed excess heat that cannot be used by the building. The fuel reformer is generally a standard 

fuel cell component for reforming natural gas, but options are available for using propane, or the 

fuel cell may use pure hydrogen without a fuel processor. The PAFC system modeled for the 

case study is fueled with commercial natural gas. Note that the cost values used in this case study 

are for illustration purposes only and are not validated or endorsed by DOE. 

The CHHP application modeled here includes several additional options for integrating the 

hydrogen co-production with a standard CHP application. In addition to the fuel cell plant—

which would include a fuel reforming system, fuel cell stacks, and power conditioning 

0.14 0.15 0.16 0.17 0.18 0.19 0.2 0.21 0.22

Total Depreciable Capital Cost ($) [1,078,630 to 1,617,944]

Process Fixed Operating Cost ($) [83,197 to 124,795]

Hydrogen compression, storage, and dispensing capital cost ($) 

[352,000 to 528,000]

Reforming fuel cell cost ($/kW) [1440 to 2160]

Federal Business Energy Tax Credit ($) [155,520 to 0]

After-tax Real IRR (fraction) [0.08 to 0.12]

LCOE ($/kWh)
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equipment—a PSA unit is used to extract hydrogen from the reformer syngas stream, and a CSD

unit is installed for vehicle refueling. 

The CHHP power model includes several additional components that can be included within the 

model analysis. These include a burner for additional heat, an electrolyzer for additional 

hydrogen production, and an additional, usually smaller, fuel cell for peak electricity demand. 

Hydrogen storage can be used for either electricity or vehicle fueling. However it is assumed that 

the fuel cell system will tie into existing building electricity, heating, cooling, and domestic hot 

water production. Equipment such as additional thermal storage will not be used; existing 

thermal water storage will be used instead.

3.3.1 Financial Inputs

Fuel Cell System

Costs for PAFC CHP plants were collected from a variety of sources, which included both actual 

projects as well as estimates and projections. The CHP plants vary from this case study in that 

they do not include the PSA for separation of hydrogen or the CSD unit for hydrogen vehicle 

filling. The data were normalized to 2005 dollars and analyzed over a period from 1993 to 2008. 

Figure 52 shows cost data collected from a number of sources [4,6,7,13–18]. An average 

installation factor of 1.15 was found between uninstalled and installed plant costs. Using several 

sources, equipment costs were estimated to be about 70% of the total capital investment, leaving 

30% for installation and indirect capital costs [3,4,6,17]. The installation factor was estimated to 

be 15% of the uninstalled equipment cost and indirect costs (site preparation, engineering design, 

project contingency, and permit licensing fees), accounting for 24% of the installed cost.

As shown in Figure 52, current costs represent actual plant costs or estimated low-volume 

production that is not taking advantage of mass-production economies of scale. References for 

the data points are shown in brackets. High-volume data points are predictions for mass 

production generally at the 100 MW/year or more level. As can be seen, the costs have 

decreased, and the yearly trend for current costs fits an exponential curve with an r-squared fit of 

0.82 for installed and 0.81 for uninstalled. The crossing of the installed and uninstalled trend 

lines is due to inconsistent cost estimates in the 2003–2008 range. One explanation is that the 

main supplier of PAFC fuel cells exited the market for several years, so while earlier data points 

are based on actual projects, some of the later data points are estimates based on past evidence. 

This inconsistency may be due to the nascent commercial status of the technology and 

uncertainties associated with the small number of data points. Trend lines for high-volume 

estimates were not fit to a curve due to few data points but they are shown for comparison. 
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Figure 52. Collected cost information for PAFC CHP plants

Equation 23. y = 8,841e-0.066x

Equation 24. x = year - 1992 

Equation 23 is the curve represented by current uninstalled low-volume production levels: y is 

the total direct and indirect capital cost in $(2005)/kW, and x is calculated as per Equation 24. 

The costs for the case study represent relatively high-volume production. The costs were 

adjusted from 2005 to 2007 dollars using the Chemical Engineering Plant Cost Index (CEPCI).

Uninstalled costs for the fuel cell plant were estimated to be $(2007)800/kW, and the natural gas 

reformer cost was estimated to be $(2007)660/kW of fuel cell AC output. 3

 The uninstalled PSA 

unit cost of $(2007)140/kW for the case study is based on the costs developed for the H2A 

Hydrogen Production forecourt SMR system (see

www.hydrogen.energy.gov/h2a_production.html). The uninstalled cost of the shift reactor was 

estimated to be $(2007)500/kW, and the system assembly and balance of plant was estimated to 

be $(2007)1,550. Total CHHP system uninstalled direct capital cost is approximately 

$(2007)3,650/kW. Installation costs average 12% for all the fuel cell system components, and 

indirect costs are 25% of the installed equipment cost. Installation and indirect costs are 

approximately $(2007)1,468/kW for a total installed capital cost of the fuel cell and hydrogen 

purification system (not including CSD) of $5,118/kW.

Literature values typically include the entire chain. Therefore, the separation of direct capital and 

indirect was estimated and then split into 10% of installed equipment cost for site preparation, 

 

3 Note that, although DOE supports fuel cell cost-estimation analysis, the $800/kW and $660/kW values are not 

derived from those efforts and should not be interpreted as a DOE-endorsed cost estimates. They are merely 

example costs.

$0

$1,000

$2,000

$3,000

$4,000

$5,000

$6,000

$7,000

$8,000

$9,000

1990 1995 2000 2005 2010

$(2005)/kW

Year

PAFC CHP Plant Costs

Current - installed

Current - uninstalled

High volume - installed

High volume - uninstalled

[13]

[14]

[15]

[17]

[7]

[4]

[16]

[16]

[14]

[13]

[15]

[17]

[6]

[4] [4]

[18]

[18]
89 

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7% for engineering and design, 5% for project contingency, and 3% for permitting fees on the 

fuel cell system facility. The values for project contingency and permitting fees were derived 

from other H2A case studies [10]. 

Operating and maintenance costs are as follows. Replacement costs are estimated to be 8% after 

the first 5 years, 39% after the first 10 years, and 8% 5 years after that. Fixed maintenance and 

repairs were estimated at 2%, and variable unplanned replacement 1.5%, of direct fuel cell 

system capital cost yearly, both estimated using figures from an EPRI report [3]. 

Hydrogen Storage and Dispensing

The hydrogen CSD system operating assumptions and costs are derived from the H2A 

production forecourt model. It is assumed that the hydrogen produced by the system will be used 

in vehicles used on public streets. The scenario envisions a very small hydrogen demand in an 

emerging market. Therefore, the hydrogen is piped a short distance to an existing conventional 

fueling station where storage tanks for about 1 day of production and a single dispenser are 

located.

3.3.2 Load Profile and Fuel Cell Specification

The hotel is assumed to have 176 rooms, a laundry, and a restaurant. The modeled building was 

six stories tall. The electricity and heat load profiles for the building are calculated building 

simulation output from the NREL building systems model [12]. The building is assumed to be an 

existing building that was constructed using typical building techniques and materials. The 

electricity load includes electricity use for air conditioning, and the heat load is fuel demand for 

both space heating and hot water. Because the heating demand profile already accounts for the 

efficiency of the furnace or boiler, the efficiency of the burner for supplementary heat in the 

CHHP system is set at 100%.

The average building electrical demand is 229 kW with peaks in demand up to 471 kW and a 

minimum value of 71 kW. The fuel cell was assumed to be 200 kW, which is a commercially 

available size, and has a maximum rated AC output just under the building’s average demand. 

For the PAFC system, the reformer can be specified separately from the fuel cell. For the case 

study, the reformer was oversized by a factor of 2 to produce additional hydrogen. 

3.3.3 Utilities

The fuel cell CHHP system is assumed to be grid parallel, with electrical connections that can be 

islanded from the grid during a power outage. Electricity demand that cannot be met by the fuel 

cell is provided by the grid. Both time-of-day and seasonal usage charges are assumed to apply. 

The base price for electricity purchased from the grid is $0.087/kWh in the startup year (2013), 

which is the EIA projected national average electricity rate for 2013. Peak rates and off-peak 

rates are 25% above and 10% below the base rate, respectively. Electricity can also be sold to the 

grid if more electricity is produced by the system than is required by the hotel at that time. 

Electricity sold to the utility is assumed to be priced at the same price as electricity would cost if 

purchased during that hour (net metering). 

The fuel cell system and auxiliary space and hot water heating systems are assumed to be fueled 

with natural gas. The natural gas rate is assumed to be the projected average national commercial 

natural gas rate, which is $10.71/MMBtu in 2013. 
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3.4 Phosphoric Acid Fuel Cell Case Study Results

3.4.1 Baseline System

The FCPower Model calculates costs for supplying electricity and heat to the building and 

purchase of an equivalent amount of hydrogen for the refueling station in the absence of the fuel 

cell system. This baseline system assumes electricity purchased from the grid, heat for hot water 

and space heating supplied by a natural gas furnace or boiler, and hydrogen production using a 

small (forecourt) natural gas SMR. Electricity for the building is purchased using the same price 

schedule as is used for the CHHP supplementary electricity supply. Natural gas for heating and 

fueling the SMR unit is purchased at the same rate as fuel for the CHHP system. Yearly costs for 

energy for the baseline system are shown in Table 12. 

Table 12. Baseline System Levelized Energy Costs (Prior to Installation of Fuel Cell) 

Electricity (use and demand charges) $238,392/year

Commercial natural gas $89,946/year

Hydrogen (from forecourt SMR system, $5.23/kg) $648,804/year

Total baseline system energy cost per year $977,142/year

3.4.2 CHHP System Energy Supply

The PAFC CHHP system supplies a yearly total of 6,142 MWh of energy in the form of 

electricity, heat, and hydrogen; no electricity is sold to the utility. Of this, 1,184 MWh (19%) are 

in the form of electricity, 826 MWh (13%) are in the form of useful heat, and the remaining 

4,133 MWh (123,993 kg, 67%) are in the form of hydrogen. The total system efficiency is 71%. 

Table 13 shows the energy supplied by the fuel cell at full operation and supplementary 

electricity and heat purchased for the building. The analysis assumes that, during construction 

and startup (about 1 year), all of the electricity and heating fuel to supply the building will be 

purchased. 

Table 13. PAFC System Building Energy Supply

System Energy to 

Building (kWh)

Percent of Energy Type 

Supplied by the CHHP 

System

System net electricity to 

building 1,183,907 59 

Fuel cell system heat 825,602 39

Hydrogen 4,132,595 (123,993 kg) 100

Supplementary Building 

Electricity and Heat 

(kWh)

Percent of Energy Type 

Supplied by 

Supplementary Systems

Supplementary electricity 928,473 41

Supplementary heat 1,388,573 61

3.4.3 CHHP System Capital Costs and Credits

For the case study, it is assumed that a commercial entity (the hotel owner) purchases the fuel 

cell system and owns and operates the refueling station equipment but rents the land for the 

refueling station, which is co-located with a gasoline refueling station adjacent to the hotel. A 

300-ft pipeline connects the CHHP system to the storage tanks and compressors at the filling 
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station. Equity financing, a 10% internal rate of return, and a 20-year life are assumed for the 

CHHP installation.

Table 14 shows the initial capital investment and federal tax credits taken for the installation.

Indirect capital investment (site preparation, engineering, contingency, and permitting) totals 

$329,525. 

Table 14. PAFC System Initial Investment and Credits

Direct capital investment (reference year, (2007)$)

Major pieces/

systems of 

equipment 

Baseline 

installed 

costs ($)

(total initial 

capital 

investment)

Depreciation 

type

Depreciation 

schedule 

(years)

Federal 

credit or 

incentive

Credit 

amount ($)

Total 

adjusted 

depreciable 

capital cost 

basis ($)a

PAFC system 

(including 

hydrogen 

purification)

818,817 MACRS 5 

Federal 

business 

energy tax 

credit

69,120 911,127

Auxiliary heater 170,754 MACRS 7 197,211

System 

integration and 

control

30,000 MACRS 7 34,648

Hydrogen 

compression, 

storage, and 

dispensing

1,107,185 MACRS 5 1,278,735

Total 2,126,757 

(2,456,28) 69,120 2,421,722

a Total depreciation basis includes indirect capital costs.

3.4.4 PAFC CHHP System Cash Flow

Figure 53 shows key expenditures and cash flow for the PAFC CHHP installation throughout its 

lifetime. Replacement costs include an allowance of 1.5% per year of the initial depreciable 

capital investment for unplanned replacement of capital equipment as well as planned 

restacking/refurbishment of the fuel cell and reformer every 5 years (8% of fuel cell capital 

investment at year 5 and 15, 39% at year 10). It is assumed that the compressors and dispensers 

will be replaced after 10 years at 35% of the initial cost for the entire CSD system. A 

replacement cost of 25% of building system integration direct capital cost is also incurred after 

10 years. Figure 53 indicates that the project will break even after approximately 7 years.
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Figure 53. PAFC CHHP key yearly expenditures and revenue

3.4.5 Cost of Hydrogen and Total Annualized Costs

The FCPower Model solves for the levelized revenue for energy supplied by the CHHP system 

(electricity, heat, and hydrogen) that will result in a net present value (including inflation and an 

internal rate of return specified by the user) of zero for the project. The user may distribute the 

required revenue between the three energy streams in any way desired. However, the default 

distribution assumes that electricity supplied by the fuel cell is “sold” at the same price as would 

have been paid for grid electricity. Similarly, heat is assumed to be supplied at the same rate as 

purchased natural gas. The levelized profited cost of hydrogen is derived by difference. For this 

installation, the cost of hydrogen is $5.92/kg as dispensed. This is comparable to the cost of 

hydrogen supplied by a forecourt SMR unit ($5.23/kg) for the baseline system. Table 15 shows 

the total annualized costs for the PAFC CHHP system. 

Table 15. Total Annualized Costs for the PAFC CHHP Installation

Annualized costs

Capital costs $451,583 

Decommissioning costs $4,277 

Fixed O&M $172,828 

Feedstock costs $247,424 

Other raw material costs $0 

Byproduct credits $0 

Other variable costs (not including supplementary 

electricity and heat)

$10,941 

Supplementary electricity $112,008 

Supplementary heat $41,958 

Total $1,041,020 

The total annualized cost for the CHHP system is similar to the energy costs for the baseline 

system of $977,142 shown in Table 12. This analysis indicates that the CHHP system could be a 

cost-effective alternative to conventional energy supply for the hotel. 

($4,000,000)

($3,000,000)

($2,000,000)

($1,000,000)

$0 

$1,000,000 

$2,000,000 

$3,000,000 

$4,000,000 

-1 2 4 6 8 10 12 14 16 18 20 

Cash Flow ($/year)

Year of Operation

Cash Flow Analysis

Yearly Replacement Costs Initial Equity Capital Investment

Other Non-Depreciable Capital Costs Taxable Income

Portion of Initial Capital Financed with Debt Cumulative Cash Flow
93 

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3.4.6 Sensitivity Analysis

Sensitivity analyses were performed for key cost elements for the CHHP system: inflation rate, 

internal rate of return, federal tax credit, CSD capital cost, fuel cell cost, process fixed operating 

cost, and total depreciable capital cost. The results, presented in terms of the levelized hydrogen 

cost, are shown in Figure 54. 

Figure 54. Sensitivity analysis for the PAFC CHHP system key costs 

3.5 Solid Oxide Fuel Cell Case Study Description

The system is assumed to be a combined heat, hydrogen, and power system. The fuel cell is sized 

to meet the average AC demand. Hydrogen CSD are assumed to closely resemble the CSD 

portion for standalone forecourt SMR hydrogen production at a comparable hydrogen production 

rate. The business is assumed to take advantage of the federal fuel cell tax credit. 

The CHHP application modeled includes additional equipment for integrating the hydrogen coproduction with a standard CHP application. In addition to the fuel cell plant—which includes a 

fuel-reforming system, fuel cell stacks, and power-conditioning equipment—a shift reactor 

converts additional CO to hydrogen, and a PSA unit extracts hydrogen from the fuel cell exhaust 

stream. A CSD unit is installed for vehicle refueling. The CSD costs do not include costs for a 

convenience store or building. 

The CHHP power model includes several additional components that can be included within the 

model analysis. These include a burner for additional heat, an electrolyzer for additional 

hydrogen production, and an additional, usually smaller fuel cell for meeting peak electricity 

0.12 0.125 0.13 0.135 0.14 0.145 0.15 0.155 0.16 0.165

Total depreciable capital cost ($) [2,000,000 to 2,950,000]

Process fixed operating cost ($) [95,000 to 142,000]

Reforming fuel cell cost ($/kW) [640 to 960]

Hydrogen compression, storage, and dispensing capital cost ($) 

[885,748 to 1,328,622]

Federal business energy tax credit ($) [69,120 to 0]

After-tax Real IRR (fraction) [0.08 to 0.12]

Inflation rate (fraction) [0.01 to 0.04]

Levelized Cost of System Output Energy ($/kWh)
94 

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demand. Hydrogen storage can be used for electricity or vehicle fueling. However, it is assumed 

that the fuel cell system will tie into existing building electricity, heating, cooling, and domestic 

hot water production. Equipment such as additional thermal storage is not used; existing thermal 

water storage is used instead. Note that the cost values used in this case study are for illustration 

purposes only and are not validated or endorsed by DOE. 

3.5.1 Financial Inputs

Fuel Cell System

The Solid State Energy Conversion Alliance (SECA)4 has set a target of $700/kW5 fuel cell rated 

AC power for SOFC systems (direct uninstalled cost for the fuel cell plant including internal 

reforming), and the case study uses this value. A shift reactor and PSA system were added for 

hydrogen production and purification from the fuel cell. The shift reactor and PSA system were 

sized for the more dilute hydrogen stream from the SOFC. The combined uninstalled cost of the 

shift reactor and fuel compressor was estimated to be $117/kW, and the uninstalled PSA cost 

was estimated to be $315/kW. Total CHHP system uninstalled direct capital cost is

approximately $1,131/kW. Installation was estimated to be 20% of the equipment cost for the 

fuel cell plant and PSA. Indirect costs are 25% of the installed equipment cost. Installation and 

indirect costs are approximately $537/kW for a total installed capital cost of the fuel cell and 

hydrogen purification system (not including CSD) of $1,668/kW.

Indirect capital costs are difficult to enumerate separately because researched costs typically 

included the entire chain. Indirect costs for project contingency and permitting were generally 

not included in literature values for costs. The values used in the FCPower Model for project 

contingency and permitting (5% and 3% of installed equipment costs, respectively) are derived 

from previous H2A hydrogen production models [10]. The separation of direct and indirect 

capital cost was estimated and then split into 10% of installed equipment cost for site preparation

and 7% for engineering and design. 

Operating and maintenance costs are as follows. Replacement costs are estimated to be 25% of 

the total fuel cell system capital cost every 10 years. Fixed maintenance and repairs were 

estimated at 2%, and variable unplanned replacement 1.5%, of direct fuel cell system capital cost 

yearly, both estimated using figures from an EPRI report [3]. 

Hydrogen Storage and Dispensing

The hydrogen CSD system operating assumptions and costs are derived from the H2A 

production forecourt model. It is assumed that the hydrogen produced by the system will be used 

in vehicles used on public streets. The scenario envisions a very small hydrogen demand in an 

emerging market. Therefore, the hydrogen is piped a short distance to an existing conventional 

fueling station where storage tanks for about 1 day of production and a single dispenser are 

located.

 

4 For information about SECA, visit http://www.netl.doe.gov/technologies/coalpower/fuelcells/seca/. 5 Note that, although DOE supports fuel cell cost-estimation analysis, the $700/kW value is not derived from those 

efforts and should not be interpreted as a DOE-endorsed cost estimate. It is merely an example cost.
95 

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3.5.2 Load Profile and Fuel Cell Specification

The hotel is assumed to have 176 rooms, a laundry, and a restaurant. The modeled building is six 

stories tall. The electricity and heat load profiles for the building are calculated using building 

simulation output from the NREL building systems model [12]. The building is assumed to be an 

existing building that was constructed using typical building techniques and materials. The 

electricity load includes electricity use for air conditioning, and the heat load is fuel demand for 

both space heating and hot water. Because the heating demand profile already accounts for the 

efficiency of the furnace or boiler, the efficiency of the burner for supplementary heat in the 

CHHP system is set at 100%.

The average building electrical demand is 229 kW with peaks in demand up to 471 kW and a 

minimum value of 71 kW. The fuel cell was assumed to be 200 kW, which is a commercially 

available size, with a maximum rated AC output just under the building’s average demand. 

3.5.3 Utilities

The fuel cell CHHP system is assumed to be grid parallel, with electrical connections that can be 

islanded from the grid during a power outage. Electricity demand that cannot be met by the fuel 

cell is provided by the grid. Both time-of-day and seasonal usage charges are assumed to apply. 

The base price for electricity purchased from the grid is $0.087/kWh in the startup year (2013), 

which is the EIA projected national average electricity rate for 2013. Peak rates and off-peak 

rates are 25% above and 10% below the base rate, respectively. Electricity can also be sold to the 

grid if more electricity is produced by the system than is required by the hotel at that time. 

Electricity sold to the utility is assumed to be priced at the same price as electricity would cost if 

purchased during that hour (net metering). 

The fuel cell system and auxiliary space and hot water heating systems are assumed to be fueled 

with natural gas. The natural gas rate is assumed to be the projected average national commercial 

natural gas rate, which is $10.71/MMBtu in 2013. 

3.6 Solid Oxide Fuel Cell Case Study Results

3.6.1 Baseline System

The FCPower Model calculates costs for supplying electricity and heat to the building and 

purchasing an equivalent amount of hydrogen for the refueling station in the absence of the fuel 

cell system. This baseline system assumes electricity purchased from the grid, heat for hot water 

and space heating supplied by a natural gas furnace or boiler, and hydrogen production using a 

small (forecourt) natural gas SMR. Electricity for the building is purchased using the same price 

schedule as is used for the CHHP supplementary electricity supply. Natural gas for heating and 

fueling the SMR unit is purchased at the same rate as fuel for the CHHP system. Yearly costs for 

energy for the baseline system are shown in Table 16. In a real-world application, a smallvolume hydrogen station like this one likely would be part of an existing conventional fuel 

station (instead of being a standalone station as assumed here) and possibly supplied with offsite-generated hydrogen via truck, which might reduce the hydrogen cost below the $12.04/kg 

shown here. 
96 

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Table 16. Baseline System Levelized Energy Costs (Prior to Installation of Fuel Cell) 

Electricity (use and demand charges) $238,392/year

Commercial natural gas (for heat) $89,946/year

Hydrogen (from forecourt SMR, $12.04/kg) $365,975/year

Total baseline system energy cost per year $694,313/year

3.6.2 CHHP System Energy Supply

The SOFC CHHP system supplies a yearly total of 2,810 MWh of energy to the building in the 

form of electricity, heat, and hydrogen, in addition to 20 MWh of electricity that is sold to the 

utility. Of this, 1,300 MWh (46%) are in the form of electricity, 500 MWh (18%) are in the form 

of useful heat, and the remaining 1,000 MWh (30,400 kg, 36%) are in the form of hydrogen. The 

total system efficiency is 75%. Table 17 shows the energy supplied by the fuel cell at full 

operation and supplementary electricity and heat purchased for the building. The analysis 

assumes that, during construction and startup (about 1 year), all of the electricity and heating fuel 

to supply the building will be purchased.

Table 17. SOFC System Building Energy Supply at Full Operation

System Energy to Building (kWh) Percent of Energy Type 

Supplied by the CHHP 

System

System net electricity to 

building 1,296,444 65

Fuel cell system heat 500,110 24

Hydrogen 1,013,213 100

Supplementary Building Electricity 

and Heat (kWh) 

Percent of Energy Type 

Supplied by 

Supplementary System

Supplementary electricity 816,510 35

Supplementary heat 1,712,405 76

Approximately 19% (312 MWh/year) of the fuel cell total electrical output of 1,628 MWh per 

year at full operation, is required for auxiliary power, primarily for the hydrogen purification 

system and compression of hydrogen to the dispensing pressure of 5,000 psi (350 bar). 

3.6.3 CHHP System Capital Costs and Credits

For the case study, it is assumed that a commercial entity (the hotel owner) purchases the fuel 

cell system and owns and operates the refueling station equipment but rents the land for the 

refueling station, which is co-located with a gasoline refueling station adjacent to the hotel. A 

300-ft pipeline connects the CHHP system to the storage tanks and compressors at the filling 

station. Equity financing, a 10% internal rate of return, and a 20-year life are assumed for the 

CHHP installation.

Table 18 shows the initial capital investment and federal tax credits taken for the installation. 

Indirect capital investment (site preparation, engineering, contingency, and permitting) totals 

$132,253. 
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Table 18. SOFC System Initial Investment and Credits

Direct capital investment (reference year, (2007)$)

Major pieces/ 

systems of 

equipment 

Baseline 

installed 

costs ($)

(with 

indirect 

capital)

Depreciation 

type

Depreciation 

schedule 

(years)

Federal 

credit or 

incentive

Credit 

amount ($)

Total 

adjusted 

depreciable 

capital cost 

basis ($)a

MCFC system 

(including 

hydrogen 

purification)

266,864 MACRS 5 

Federal 

business 

energy tax 

credit

60,480 274,903

Auxiliary heater 170,754 MACRS 7 195,247

System 

integration and 

control

30,000 MACRS 7 34,303

Hydrogen 

compression, 

storage, and 

dispensing

454,381 MACRS 5 519,558

Total 921,999

(1,054,252) 60,480 1,024,012

a Total depreciation basis includes indirect capital costs.

3.6.4 SOFC CHHP System Cash Flow

Figure 55 shows key expenditures and cash flow for the SOFC CHHP installation throughout its 

lifetime. Yearly replacement costs include an allowance of 1.5% of the initial depreciable capital 

investment for unplanned replacement of capital equipment as well as planned restacking of the 

fuel cell every 10 years. It is assumed that the compressors and dispensers will be replaced after 

10 years at 35% of the initial cost for the entire CSD system. A replacement cost of 25% of 

building system integration direct capital cost is also incurred after 10 years. Figure 55 indicates 

that the project will break even after approximately 7 years.

Figure 55. SOFC CHHP key yearly expenditures and revenue

($1,500,000)

($1,000,000)

($500,000)

$0 

$500,000 

$1,000,000 

$1,500,000 

$2,000,000 

-1 2 4 6 8 10 12 14 16 18 20 

Cash Flow ($/year)

Year of Operation

Cash Flow Analysis

Yearly Replacement Costs Initial Equity Capital Investment

Other Non-Depreciable Capital Costs Taxable Income

Portion of Initial Capital Financed with Debt Cumulative Cash Flow
98 

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3.6.5 Cost of Hydrogen and Total Annualized Costs

The FCPower Model solves for the levelized revenue for energy supplied by the CHHP system 

(electricity, heat, and hydrogen) that will result in a net present value (including inflation and an 

internal rate of return specified by the user) of zero for the project. The user may distribute the 

required revenue between the three energy streams in any way desired. However, the default 

distribution assumes that electricity supplied by the fuel cell is “sold” at the same price as would 

have been paid for grid electricity. Similarly, heat is assumed to be supplied at the same rate as 

purchased natural gas. The levelized profited cost of hydrogen is derived by difference. For this 

installation, the cost of hydrogen is $10.54/kg as dispensed. This compares favorably to the cost 

of hydrogen supplied by a forecourt SMR unit ($12.04/kg) for the baseline system. Table 19

shows the total annualized costs for the SOFC CHHP system.

Table 19. Total Annualized Costs for the SOFC CHHP Installation

Annualized costs

Capital costs $187,462 

Decommissioning costs $1,819 

Fixed O&M $125,542 

Feedstock costs $165,829 

Other raw material costs $0 

Byproduct credits –$1,776

Other variable costs (excluding supplementary 

electricity and heat)

$4,450 

Supplementary electricity $99,523 

Supplementary heat $77,880 

Total $660,729 

The total annualized cost for the CHHP system is less than the energy costs for the baseline 

system of $694,313 shown in Table 16. This analysis indicates that the CHHP system could be a 

cost-effective alternative to conventional energy supply for the hotel. 

3.6.6 Sensitivity Analysis

Sensitivity analyses were performed for six key cost elements for the CHHP system: internal rate 

of return, federal business energy tax credit, reforming fuel cell cost, CSD cost, process fixed 

operating cost, and total depreciable capital cost. The results, presented in terms of levelized 

energy cost, are shown in Figure 56. 
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Figure 56. Sensitivity analysis for the SOFC CHHP system key costs (LCOE in $/kWh)

0.14 0.15 0.16 0.17 0.18 0.19 0.2

Total Depreciable Capital Cost ($) [843,401 to 1,265,102]

Process Fixed Operating Cost ($) [79,186 to 118,779]

Hydrogen compression, storage, and dispensing capital cost ($) 

[363,505 to 545,257]

Reforming fuel cell cost ($/kW) [560 to 840]

Federal Business Energy Tax Credit [60480 to 0]

After-tax Real IRR (fraction) [0.08 to 0.12]

Levelized Cost of System Output Energy ($/kWh)
100 

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