IPM Model – Updates to Cost and Performance for APC Technologies

SDA FGD Cost Development Methodology

Final

March 2013

Project 12847-002

Systems Research and Applications Corporation

Prepared by

55 East Monroe Street • Chicago, IL 60603 USA • 312-269-2000
LEGAL NOTICE

This analysis ("Deliverable") was prepared by Sargent & Lundy, L.L.C. ("S&L"), expressly for the sole use 

of Systems Research and Applications Corporation ("Client") in accordance with the agreement between 

S&L and Client. This Deliverable was prepared using the degree of skill and care ordinarily exercised by 

engineers practicing under similar circumstances. Client acknowledges: (1) S&L prepared this Deliverable 

subject to the particular scope limitations, budgetary and time constraints, and business objectives of the 

Client; (2) information and data provided by others may not have been independently verified by S&L; and 

(3) the information and data contained in this Deliverable are time sensitive and changes in the data, 

applicable codes, standards, and acceptable engineering practices may invalidate the findings of this 

Deliverable. Any use or reliance upon this Deliverable by third parties shall be at their sole risk. 

This work was funded by the U.S. Environmental Protection Agency and reviewed by William A. Stevens, 

Senior Advisor – Power Technologies. 
IPM Model – Updates to Cost and Performance for 

APC Technologies

Project No. 12847-002

March 2013

SDA FGD Cost Development Methodology

Page 1

Establishment of Cost Basis

Cost data for the SDA FGD systems based on actual installations was more limited than 

that for the wet FGD systems. A similar trend of capital cost with generating capacity

(MW size) is generally seen between the wet and SDA system. The same least square 

curve fit power relationship for capital costs as a function of generating capacity, up to 

600 MW, was used for the wet and SDA cost estimation with the constant multiplier

adjusted to ensure that the curve represented the data available.

The curve fit was set to represent proprietary in-house cost data of a "typical" SDA FGD 

retrofit for removal of 95% of the inlet sulfur. It should be noted that the lowest available 

SO2 emission guarantees, from the original equipment manufactures of SDA FGD 

systems, are 0.06 lb/MMBtu. The typical SDA FGD retrofit was based on:

Retrofit Difficulty = 1 (Average retrofit difficulty);

Gross Heat Rate = 9800 Btu/kWh;

SO2 Rate = 2.0 lb/MMBtu;

Type of Coal = PRB;

Project Execution = Multiple lump sum contracts; and

Recommended SO2 emission floor = 0.08 lb/MMBtu.

Units below 50 MW will typically not install an SDA FGD system. Sulfur reductions for 

the small units would be accomplished by; treating smaller units at a single site with one 

SDA FGD system, switching to a lower sulfur coal, repowering or conversion to natural 

gas firing, dry sorbent injection, and/or a reduction in operating hours. Capital costs of 

approximately $1,000/kW may be used for units below 50 MW under the premise that 

these will be combined.

Based on the typical SDA FGD performance, the technology should not be applied to 

fuels with more than 3 lb SO2/MMBtu and the cost estimator should be limited to fuels 

with less than 3 lb SO2/MMBtu.

An alternate dry technology, circulating dry scrubber (CDS), can meet removals of 98% 

or greater over a large range of inlet sulfur concentrations. It should be noted that the 

lowest SO2 emission guarantees for a CDS FGD system are 0.04 lb/MMBtu. Recent 

industry experience has shown that a CDS FGD system has a similar installed cost to a 

comparable SDA FGD system.
IPM Model – Updates to Cost and Performance for 

APC Technologies

Project No. 12847-002

March 2013

SDA FGD Cost Development Methodology

Page 2

Methodology

Inputs

Several input variables are required in order to predict future retrofit costs. The gross 

unit size in MW (equivalent acfm) and sulfur content of the fuel are the major variables

for the capital estimation. A retrofit factor that equates to difficulty in construction of 

the system must be defined. The costs herein could increase significantly for congested 

sites. The unit gross heat rate will factor into the amount of flue gas generated and 

ultimately the size of the absorber, reagent preparation, waste handling, and balance of 

plant costs. The SO2 rate will have the greatest influence on the reagent handling and 

waste handling facilities. The type of fuel (Bituminous, PRB, or Lignite) will influence 

the flue gas quantities as a result of the different typical heating values.

The cost methodology is based on a unit located within 500 feet of sea level. The actual 

elevation of the site should be considered separately and factored into the cost due to the 

effects on the flue gas volume. The base absorber island and balance of plant costs are 

directly impacted by the site elevation. These two base cost modules should be increased 

based on the ratio of the atmospheric pressure between sea level and the unit location. As 

an example, a unit located 1 mile above sea level would have an approximate 

atmospheric pressure of 12.2 psia. Therefore, the base absorber island and balance of 

plant costs should be increased by:

14.7 psia/12.2 psia = 1.2 multiplier to the base absorber island and balance of plant costs

Outputs

Total Project Costs (TPC)

First the installed costs are calculated for each required base module. The base module 

installed costs include:

All equipment;

Installation;

Buildings;

Foundations;

Electrical; and

Retrofit difficulty.

The base modules are:
IPM Model – Updates to Cost and Performance for 

APC Technologies

Project No. 12847-002

March 2013

SDA FGD Cost Development Methodology

Page 3

BMR = Base absorber island cost

BMF = Base reagent preparation and waste recycle/handling cost

BMB = Base balance of plant costs including: ID or booster fans, piping, ductwork and 

reinforcement, electrical, etc...

BM = BMR + BMF + BMB

The total base module installed cost (BM) is then increased by:

Engineering and construction management costs at 10% of the BM cost;

Labor adjustment for 6 x 10 hour shift premium, per diem, etc., at 10% of the 

BM cost; and

Contractor profit and fees at 10% of the BM cost.

A capital, engineering, and construction cost subtotal (CECC) is established as the sum of 

the BM and the additional engineering and construction fees.

Additional costs and financing expenditures for the project are computed based on the 

CECC. Financing and additional project costs include:

Owner's home office costs (owner's engineering, management, and 

procurement) at 5% of the CECC; and

Allowance for Funds Used During Construction (AFUDC) at 10% of the 

CECC and owner's costs. The AFUDC is based on a three-year engineering 

and construction cycle.

The total project cost is based on a multiple lump sum contract approach. Should a 

turnkey engineering procurement construction (EPC) contract be executed, the total 

project cost could be 10 to 15% higher than what is currently estimated.

Escalation is not included in the estimate. The total project cost (TPC) is the sum of the 

CECC and the additional costs and financing expenditures. 

Fixed O&M (FOM)

The fixed operating and maintenance (O&M) cost is a function of the additional 

operations staff (FOMO), maintenance labor and materials (FOMM), and administrative 

labor (FOMA) associated with the SDA FGD installation. The FOM is the sum of the 

FOMO, FOMM, and FOMA.
IPM Model – Updates to Cost and Performance for 

APC Technologies

Project No. 12847-002

March 2013

SDA FGD Cost Development Methodology

Page 4

The following factors and assumptions underlie calculations of the FOM:

All of the FOM costs were tabulated on a per kilowatt-year (kW yr) basis.

In general, 8 additional operators are required for a SDA FGD system. The 

FOMO was based on the number of additional operations staff required.

The fixed maintenance materials and labor (includes bag replacement) is a 

direct function of the process capital cost at 1.5% of the BM.

The administrative labor is a function of the FOMO and FOMM at 3% of 

(FOMO + 0.4FOMM).

Variable O&M (VOM)

Variable O&M is a function of:

Reagent use and unit costs;

Waste production and unit disposal costs;

Additional power required and unit power cost; and

Makeup water required and unit water cost.

The following factors and assumptions underlie calculations of the VOM:

All of the VOM costs were tabulated on a per megawatt-hour (MWh) basis.

The reagent usage is a function of gross unit size, SO2 feed rate, and removal 

efficiency. While the capital costs are based on a 95% sulfur removal design, 

the operating sulfur removal percentage can be adjusted to reflect actual 

variable operating costs.

In addition to sulfur removal efficiency, the estimated reagent usage was 

based on a flue gas temperature into the SDA FGD of 300°F and an adiabatic 

approach to saturation of 30°F.

The calcium-to-sulfur stoichiometric ratio varies based on inlet sulfur. The 

variation in stoichiometric ratio was accounted for in the estimation. The 

economic estimation is only valid up to 3 lb SO2/MMBtu inlet.

The basis for the lime purity was 90% CaO with the balance being inert 

material.
IPM Model – Updates to Cost and Performance for 

APC Technologies

Project No. 12847-002

March 2013

SDA FGD Cost Development Methodology

Page 5

The waste generation rate is a function of inlet sulfur and calcium to sulfur 

stoichiometry. Both variables are accounted for in the waste generation 

estimation. The waste disposal rate is based on 10% moisture in the byproduct.

The additional power required includes increased fan power to account for the 

added SDA FGD pressure drop. This requirement is a function of gross unit 

size (actual gas flow rate) and sulfur rate.

The additional power is reported as a percent of the total unit gross 

production. In addition, a cost associated with the additional power 

requirements can be included in the total variable costs.

The makeup water rate is a function of gross unit size (actual gas flow rate) 

and sulfur feed rate.

Input options are provided for the user to adjust the variable O&M costs per unit. 

Average default values are included in the base estimate. The variable O&M costs per 

unit options are:

Lime cost in $/ton;

Waste disposal costs in $/ton;

Auxiliary power cost in $/kWh;

Makeup water costs in $/1000 gallon; and

Operating labor rate (including all benefits) in $/hr.

The variables that contribute to the overall VOM are:

VOMR = Variable O&M costs for lime reagent

VOMW = Variable O&M costs for waste disposal

VOMP = Variable O&M costs for additional auxiliary power

VOMM = Variable O&M costs for makeup water

The total VOM is the sum of VOMR, VOMW, VOMP, and VOMM. Table 1 shows a 

complete capital and O&M cost estimate worksheet for an SDA FGD.
IPM Model – Updates to Cost and Performance for APC Technologies Project No. 12847-002

March 2013

SDA FGD Cost Development Methodology

Page 6

Table 1. Example Complete Cost Estimate for an SDA FGD System
IPM Model – Updates to Cost and Performance for APC Technologies Project No. 12847-002

March 2013

SDA FGD Cost Development Methodology

Page 7