TOPICAL REPORT NUMBER 22 March 2003

The JEA Large-Scale CFB 

Combustion Demonstration Project
topical report number 22 March 2003

A report on a project conducted jointly under 

a Cooperative Agreement between: 

The U.S. Department of Energy and JEA

The JEA Large-Scale 

CFB Combustion 

Demonstration Project
Cover Picture:

Three views of JEA 

Northside Station,

Jacksonville, Florida
The JEA Large-Scale 

CFB Combustion 

Demonstration Project

Executive Summary..........................................................................1

Background.......................................................................................2

Project Description............................................................................3

Process Description...........................................................................5

Environmental Considerations..........................................................7

Project Cost.......................................................................................9

Project History ................................................................................11

Project Objectives...........................................................................16

Project Scope ..................................................................................17

Fluidized Bed Combustion Systems...............................................19

Demonstration Test Program ..........................................................23

Operating Results............................................................................23

Awards ............................................................................................24

Commercial Applications................................................................24

Conclusions.....................................................................................24

Bibliography ...................................................................................25

List of Acronyms and Abbreviations ..............................................26

Contacts for CCT Projects and U.S. DOE CCT Program...............28

1

Executive 

Summary

The Clean Coal Technology (CCT) Demonstration Program is a government and 

industry co-funded ef fort to demonstrate a 

new generation of innovative coal utilization 

processes in a series of facilities built across 

the country. These projects are carried out on 

a commercial scale to prove technical feasibility and provide the information required 

for future applica tions.

The goal of the CCT Program is to furnish 

the marketplace with a number of advanced, 

more effi cient coal-based technologies that 

meet strict envir onmental standards. Use of 

these tech nologies is intended to minimize 

the econ omic and en viron mental barriers that 

limit the full utilization of coal.

To achieve this goal, beginning in 1985, 

a multi-phased effort consisting of fi ve 

separate solic itations was admini stered by 

the U.S. De partment of Energy’s (DOE) 

National Energy Technol ogy Laboratory 

(NETL). Pro jects se lected through these 

solicita tions have demonstrated technology 

options with the poten tial to meet the needs 

of en ergy markets while satis fying relevant 

envir onment al requirements.

Part of this Program is the demonstration of advanced electric power generation 

technologies, including circulating fl uidized 

bed combustion (CFB). This report discusses 

the JEA Large-Scale CFB Combustion Demonstration Project which is testing the CFB 

concept using inexpensive feedstocks such 

as high sulfur coal and coal fuel blends.

The project is being conducted at the 

Northside Generating Station of JEA (formerly Jacksonville Electric Authority) in 

Jacksonville, Florida, and JEA is the project 

Participant. Foster Wheeler Energy Corporation, the technology supplier, is an additional 

team member.

To date, the JEA Project has operated CFBs 

to generate electricity at a scale larger than 

previously demonstrated. The boilers at the 

Northside Station are the largest CFBs in 

the world. Power production on coal feed 

meets the target goal of 297.5 MWe gross 

(265 MWe net). Emissions of atmospheric 

pollutants are below the stringent limits set 

for this project. A two-year demonstration 

test program is planned to evaluate the operational and environmental performance of 

the CFB system.

JEA plant with CFB boilers in center and fuel storage domes in background
2 

The JEA Large-Scale 

CFB Combustion 

Demonstration Project

Background

The Clean Coal Technology (CCT) Demonstration Program, sponsored by the U.S. Department of Energy (DOE) and administered 

by the National Energy Technology Laboratory 

(NETL), has been conducted since 1985 to 

develop innovative, environmentally friendly 

coal utilization processes for the world energy 

marketplace.

The CCT Program, which is co-funded by 

industry and government, involves a series of 

demonstration projects that provide data for 

design, construction, operation, and technical/

economic evaluation of full-scale applications. 

The goal of the CCT Program is to enhance the 

utilization of coal as a major energy source.

Fluidized Bed Combustion

Among the technologies being demonstrated in the CCT Program is fluidized bed 

combustion (FBC). FBC is an advanced electric 

power generation process that minimizes the 

formation of gaseous pollutants by controlling 

coal combustion parameters and by injecting 

a sorbent (such as crushed limestone) into the 

combustion chamber along with the fuel. In the 

JEA project described in this report, the fuel 

is coal or a blend of coal and petroleum coke. 

Crushed fuel mixed with the sorbent is fluidized on jets of air in the combustion chamber. 

Sulfur released from the fuel as sulfur dioxide 

(SO2) is captured by the sorbent in the bed 

to form a solid compound that is removed 

with the ash. The resultant by-product is a 

dry, benign solid that can be disposed of easily or used in agricultural and construction 

applications. More than 90% of the sulfur in 

the fuel is captured in this process.

An additional environmental benefit of 

FBC power plants results from their relatively low operating temperature, which 

significantly reduces formation of nitrogen 

oxides (NOx).

Five FBC demonstration projects are included in the CCT Program under Advanced 

Electric Power Generation: (1) the JEA LargeScale CFB Combustion Demonstration Project, (2) the Nucla CFB Demonstration Project, 

(3) the Tidd PFBC Demonstration Project, (4) 

the McIntosh Unit 4A PCFB Demonstration 

Project, and (5) the McIntosh Unit 4B Topped 

PCFB Demonstration Project. This Topical 

Report describes the JEA project.
3

Project Description

The JEA Large-Scale CFB Combustion 

Demonstration Project consists of installing 

a new 300-MWe (297.5-MWe nameplate) atmospheric circulating fl uidized bed (ACFB) 

boiler in conjunction with an existing turbine 

generator at JEA’s Northside Generating Station (Unit 2) in Jacksonville, Florida. In parallel with this project, JEA replaced the Unit 

1 oil/gas fi red boiler with an identical ACFB 

unit. Unit 1 continues to use its existing turbine generator.

These boilers are designed to burn fuel 

blends consisting of coal and petroleum coke, 

thereby greatly reducing plant fuel costs and 

maintaining fuel fl exibility while meeting 

stringent emissions limits. These units are 

the world’s largest ACFB boilers.

In this project, the existing Unit 2 turbine 

generator was upgraded, and other existing 

balance-of-plant (BOP) equipment and systems were either upgraded or replaced. The 

existing turbine building and some piping 

systems were re-utilized.

Steam from the combustor is used in an 

existing General Electric 297.5-MWe (nameplate) turbine to produce electric power. With 

para sitic power consuming 32.5 MWe, net 

power output is 265 MWe.

Panoramic view of JEA site
4 

Jacksonville

A half century after Ponce de Leon claimed Florida for Spain, Frenchman Jean Ribault sailed into the St. Johns River 

to establish Fort Caroline for French Huguenot settlers. Within several years, Spanish forces from the military garrison at 

St. Augustine would destroy this small settlement.

In 1821, Spain ceded Florida to the United States, and one year later Isaiah D. Hart surveyed the village. He named it 

Jacksonville for General Andrew Jackson, the territory’s first military governor.

Today, located at the crossroads of two transcontinental highways, Jacksonville is one of the Nation’s largest cities in 

land area (841 square miles), a major port, site of Navy bases, and home of the NFL Jacksonville Jaguars, a Mayo Clinic 

medical center, and the Jacksonville Zoological Gardens. The area boasts beautiful beaches and numerous waterways 

for over 700,000 residents.

JEA Large-Scale CFB 

Combustion 

Demonstration Project

Project Participants and Responsibilities

JEA

• Overall project and construction 

management

• Funding ($234 million)

• Environmental permitting

U.S. DOE

• Funding ($75 million)

• Technology support/dissemination

Foster Wheeler Energy Corporation 

(Clinton, NJ)

• Design and supply of CFBs

• Engineering/procurement/

construction for the extended boiler 

island, including CFBs, scrubbers, 

fabric filters, stack, and fuel and 

limestone preparation facilities

Black & Veatch (Kansas City, MO)

• Design of BOP and materials handling systems

Zachry Construction Corporation 

(San Antonio, TX)

• Procurement and construction of 

BOP system upgrades and replacements, including condensate, 

feedwater, and circulating water 

systems; water and wastewater 

treatment systems; distributed 

control system; station electric 

distribution system; and substation 

equipment

Fluor Global Services (Irvine, CA)

• Upgrade/uprate of turbine/

generators

• Procurement and construction 

of materials handling systems, 

including continuous ship unloader (purchased by JEA), pier, 

conveyors, fuel storage domes, 

and fuel and limestone reclaim 

equipment

Project Participant

The Participant is JEA, who provided the 

host site. An additional team member is Foster 

Wheeler Energy Corporation (FWEC), who 

supplied the ACFB technology.

Fuel Supply

Coal feed is an Eastern bituminous coal 

having a sulfur content of 3.39 wt%. Petroleum coke having a sulfur content as high 

as 8% also serves as feed, either alone or in 

combination with coal.

Project Scale

The JEA project represents a scale-up of 

previous ACFB installations. The Nucla project, completed in 1992, had a capacity of 100 

MWe (net) and the Tidd project, completed 

in 1995, had a capacity of 70 MWe (net). The 

McIntosh Unit 4A project (currently on hold) 

is designed for a capacity of 137 MWe (net), 

and the McIntosh Unit 4B project (also on 

hold) has a design capacity of an additional 

103 MWe (net). At a nominal design capacity 

of 300 MWe gross (265 MWe net), the JEA 

project is the largest scale demonstration of 

FBC technology to date.
5

Process Descrip tion

Coal fuel blends, along with primary air 

and a solid sorbent such as limestone, are introduced into the lower part of the combustor, 

where initial combustion occurs. As the fuel 

particles decrease in size due to combustion, 

they are carried higher in the combustor where 

secondary air is introduced. As the particles 

continue to be reduced in size the fuel, along 

with some of the sorbent, is carried out of the 

combustor, collected in a cyclone separator, and 

recycled to the lower portion of the combustor. Primary removal of sulfur is achieved by 

reaction with the sorbent in the bed. Additional 

SO2 removal is achieved through the use of a 

downstream polishing scrubber using a spray 

dryer absorber (SDA). Fabric fi lters are used 

for particulate control.

Furnace temperature is maintained in the 

range of 1500 to 1700°F by effi cient heat transfer 

between the fl uid bed and the water walls in the 

boiler. This relatively low operating temperature 

inherently results in appreciably lower NOx 

emissions compared with PC-fi red power plants. 

However, the project also includes a new selective non-catalytic reduction (SNCR) system, 

using reaction with ammonia to further reduce 

NOx emissions to very low levels as required 

by the stringent environmental regulations for 

the JEA project.

Steam is generated in tubes placed along 

the walls of the combustor and superheated 

in tube bundles placed downstream of the 

particulate separator to protect against erosion. The system produces approximately 2 

million lb/hr of main steam at 2,500 psig and 

1,000°F, and 1.73 million lb/hr of reheat steam 

at 548 psig and 1,000°F. The steam fl ows to 

the turbine/generator, where electric power is 

produced. The design heat rate is 9,950 Btu/kWh 

(34% overall thermal effi cien cy, higher heating 

value basis).

The JEA CCT project incorporates several 

advanced features including a patented integrated recycle heat exchanger (INTREXTM) 

in the furnace.

Two 400-foot diameter by 140-foot high aluminum geodesic domes for fuel storage

Limestone conveyors
6 

Details of the JEA Project Systems

Limestone Preparation System

The limestone preparation system grinds and dries raw 

limestone and pneumatically transports it to the limestone 

storage silo for each Unit. The limestone grinding system 

consists of three rod mills with accessories. The mills are 

sized for grinding limestone at a maximum feed size of 

1 inch to a product size of -2000 microns (approximately 

1/16 inch), meeting the CFB desired product distribution 

curve, with a residual moisture content of 1% maximum.

Three pneumatic transfer systems are provided to convey the prepared limestone from the preparation building 

to the unit’s silo. Each silo has a bin vent filter to control 

dust emissions. Each system is sized for 50 tons per hour 

(tph) capacity and is capable of transferring limestone to 

either Unit 1 or 2.

The control system for the limestone preparation system uses a programmable logic controller (PLC) with a 

cathode ray tube (CRT)-based operator interface located 

in the material handling control room. A digital communication interface is furnished to tie this local control system 

into the plant’s distributed control system (DCS).

Air Quality Control System

To optimize overall plant performance, a polishing SO2

scrubber was included in the design. The polishing scrubber is an SDA/baghouse combination. The SDA utilizes a 

dual fluid nozzle atomized with air, and the baghouse is a 

pulse-jet design. A key feature of the polishing scrubber is 

a recycle system which adds fly ash to the reagent feed, 

thus utilizing the unreacted lime in the fly ash from the 

CFB boiler and reducing the amount of fresh lime required.

The polishing scrubber for each unit, provided by 

Wheelabrator Air Pollution Control, consists of:

• A two-fluid nozzle SDA

• A medium-pressure pulse jet fabric filter (FF)

• A feed slurry preparation system

• A common sorbent preparation system, consisting of a 

lime storage silo, redundant vertical ball mill slaking systems, and redundant transfer/storage tanks and pumps

• A common air compressor system to provide atomizing 

air for the SDA, dried pulse air for the FF, and instrument 

air. The compressors are provided with a closed loop 

cooling system. Waste heat from the compressor is used 

to preheat the reuse water feed to the SDA feed slurry 

system.

Turbine Generator and Balance of Plant Systems

The Units 1 and 2 turbine generators were upgraded to 

maximize output and improve turbine heat rate as much 

as practical. The high pressure/intermediate pressure rotor, diaphragms, and inner casing were replaced with a GE 

Dense Pack design, which added four stages to the turbine and increased turbine efficiency. The normal operating throttle pressure was also increased from 2400 psig to 

2500 psig. In addition, the original mechanical linkage type 

turbine control system was replaced with a state-of-theart Mark VI electrohydraulic control system to allow better 

response to load changes and for complete integrated 

control, protection, and monitoring of the turbine generator 

and accessories. A new brushless excitation system was 

also installed on each generator, and a new turbine lubeoil conditioner was installed (Unit 2 only).

Unit 2 was originally designed to provide power to the 

JEA grid at 138 kV. However, to better interface with present and future grid capabilities, the output from Unit 2 was 

increased to 230 kV. This required replacement of the 

generator step-up transformer and associated substation 

upgrades.

The once-through circulating water system was upgraded by replacing the original 90% copper/10% nickel 

heat-transfer surfaces in the condenser damaged by 

erosion/corrosion with modular bundles consisting of titanium tubes welded to solid titanium tubesheets. The 

existing circulating water pumps were replaced with larger 

capacity pumps. The traveling screens were replaced with 

those that have man-made basket material to increase 

their life. Debris filters were added to minimize condenser 

tube pluggage and possible damage. A sodium hypochlorite shock-treatment system was installed to prevent sea 

life from adhering to the titanium components of the condenser.

Upgrades to the condensate system in Units 1 and 2 included upgrading the condensate pumps and condensate 

booster pumps, replacement of the steam packing exhausters, replacement of the LP feedwater heaters, including replacement of the tube bundle in the lowest pressure 

heater (located in the condenser neck), replacement of 

the deaerator and storage tank, installation of a new concontinued on page 8
7

Environmental 

Considerations

The JEA project site is located in North 

Jacksonville, an environmentally sensitive 

area surrounded by wetlands. A major goal of 

the project is to minimize emissions of solid, 

liquid and gaseous wastes. JEA is committed 

to making Jacksonville “the premier city in the 

Southeast in which to live and do business.” 

Through consultation with community and 

environmental groups including the Sierra 

Club Northeast Florida Group, JEA agreed to 

emissions limits that are signifi cantly lower than 

those specifi ed by current EPA regulations.

Sierra Club Agreement

As part of the agreement with the Sierra Club, 

baseline stack emission rates at JEA for Units 1, 

2, and 3 in 1994-1995, in tons/yr of certain substances, were identifi ed. Target annual emissions 

rates representing a 10% reduction in each of 

these components were calculated, and a penalty 

of $1000/ton was established for any emissions 

exceeding these rates regardless of whether 

such emissions are allowable under any permit 

or authorization. Payments are to be made to the 

Jacksonville Environmental Protection Board, 

earmarked for public environmental education. 

The stack emissions involved in this agreement 

are NOx, SO2, particulate matter, CO, and volatile organic compounds (VOCs). In addition, the 

utility negotiated limits for trace metals.

JEA also agreed to reduce groundwater 

consumption by at least 10%, and a penalty 

of $1000/million gallons was established for 

any groundwater usage at JEA exceeding the 

agreed upon rate of 208.4 million gallons/yr, 

regardless of whether such usage is allowable 

under any permit or authorization.

These reductions in stack emissions and 

groundwater consumption are especially signifi cant in light of the fact that total power 

production at JEA after repowering is about 

2.7 times as great as the baseline level.

Timucuan Ecological 

and Historic Preserve

Designated February 16, 1988

The 46,000 acre Timucuan Ecological and Historic Preserve was 

established in 1988 to protect one 

of the last unspoiled coastal wetlands on the Atlantic Coast and to 

preserve historic and prehistoric 

sites within the area. The estuarine 

ecosystem includes salt marsh, 

coastal dunes, and hardwood hammock as well as salt, fresh, and 

brackish waters. All of these are rich 

in native vegetation and animal life.

The Preserve was inhabited by 

the native Timucuan people for over 

4,000 years before the arrival of the 

fi rst Europeans. The Timucuan Preserve has within its boundaries federal, state, and city park lands and 

over 300 private landowners.

Wetlands adjoining the JEA Plant site
8 

densate polisher (Unit 2 only), and installation of new 

chemical feed systems (Unit 2 only). The new feedwater 

heaters included Type 304 N stainless steel tubes (welded to tubesheets), instead of the aluminum brass tubes 

rolled into the tubesheets of the original heaters.

Upgrades to the feedwater system in Unit 2 included 

replacement of the HP feedwater heaters, upgrading of 

boiler feed pumps and fluid drives, and replacement of 

the boiler feed pump drive motor. Again, the new feedwater heaters included Type 304 N stainless steel tubes 

(welded to tubesheets), instead of the aluminum brass 

tubes rolled into the tubesheets of the original heaters.

The capability of existing piping systems and components was reviewed to confirm adequacy for the new 

operating and design conditions, and where necessary 

they were upgraded or replaced. Existing 2-inch and 

larger valves in Unit 2 were either refurbished or replaced. Nearly all 2-inch and smaller piping and valves 

in Unit 2 were replaced. Essentially all instrumentation in 

Unit 2 was replaced.

The original control systems in Units 1 and 2 were replaced with a new DCS provided by ABB Inc, to provide 

control, monitoring, and protection of the boiler, turbine 

interfaces, and BOP systems. Foster Wheeler provided 

the logic design for the CFB boiler, and Black & Veatch 

provided the logic design for the BOP systems, including 

provisions for turbine water induction prevention. ABB 

provided the programming to implement the logic design 

for the boiler and BOP systems.

The Units 1 and 2 auxiliary electric systems (switchgear and motor control centers) were replaced because 

of equipment obsolescence. All power and control wiring 

was replaced due to the age of the wiring and because 

the existing control wiring was not segregated from the 

power wiring, thus not meeting the requirements of the 

new DCS.

Other miscellaneous modifications included the 

installation of additional air dryers and screw-type air 

compressors as well as the installation of titanium platetype heat exchangers for the Unit 2 closed cooling water 

system, similar to those previously installed in Unit 1.

Fuel Handling System

The function of the fuel handling system is to receive 

petroleum coke, coal, and limestone and convey it to 

stock-out and storage areas. The materials are reclaimed and conveyed to the in-plant fuel silos and to 

the limestone preparation system for limestone sorbent.

Receiving System

Solid fuels and limestone are received at the Northside river terminal. A new 800-ft dock and over 2 miles 

of new belt conveyors were installed as part of the project. Fuels are delivered in 60,000-ton capacity ships 

and limestone in 40,000-ton ships. The fuel ships are 

unloaded by a state-of-the-art continuous bucket type 

unloader rated at 1,666 tph for coal and 1,500 tph for 

petroleum coke. The unloader is guided by a sophisticated electronic control system. Limestone is unloaded 

at a rate of 2,800 tph.

Solid fuels are stored in two 400-ft diameter by 140-

ft high geodesic domes, made of aluminum, having a 

capacity of 60,000 tons. These domes serve to keep the 

fuel dry and to reduce fugitive dust emissions as well as 

storm water runoff. They are built with only outside support structures to eliminate pyramiding of coal dust in 

the interior.

Reclaim Systems

The reclaim systems used for moving feed materials 

from storage to the boilers are redundant. Each storage facility can provide sufficient reclaim rate for the 

two operating units. With two storage domes and two 

stacker/reclaimers, the coal and petroleum coke can be 

blended. Each reclaim system can deliver coal or petroleum coke at a rate of up to 600 tph.

Common Equipment

Dust suppression systems are provided at all material transfer points. The systems are of the foam type 

and directly control dust emissions at all transfer areas 

except the crusher building and the area adjacent to and 

above the in-plant storage silos, which have dust collectors. Reuse water is used for the foam type dust suppression system.

Dust collection systems collect and return the dust to 

the surge bins, or downstream of the collection points in 

the case of the collection points in the crusher building. 

The dust collected in the in-plant storage silo area is returned to one of two in-plant fuel storage silos.

A PLC based control system controls the fuel handling system and is provided with remote control for belt 

conveyors and associated equipment and necessary 

interlock control for the conveyors and machines (ship 

unloader and stacker/reclaimers). continued on page 10
9

Emissions Targets

Design emission rate for NOx is 0.09 lb/

million Btu, which is achieved by the use of 

relatively low operating temperatures in the 

CFB coupled with post-combustion reduction 

of NOx via SNCR.

For SO2, the design emission rate is 0.15 

lb/million Btu, which is achieved through 

the use of a sorbent for sulfur capture in the 

combustor, coupled with scrubbing of the 

fl ue gas.

For particulate matter having a diameter 

of 10 microns (μm) or less (PM10), the design 

emission rate is 0.011 lb/million Btu. Fabric 

fi lters are used to achieve this low level of 

particulate emissions.

Fugitive emissions are controlled by minimizing the number of bulk material transfer 

points, enclosing conveyors and drop points, 

enclosing the fuel storage area, and using wet 

suppression for particulates.

The reduction in groundwater consumption is achieved by using treated wastewater 

from a nearby municipal facility for certain 

plant applications.

Project Cost

The estimated cost of the JEA Large-Scale 

CFB Combustion Demonstration Project is 

$309 million, of which the Participant provided $234 million (76%) and DOE provided 

$75 million (24%). The repowering of Unit 

1, which is not cost shared by DOE, is not 

included in this cost fi gure.

Stack Emission Rates in Sierra Club Agreement

Parameter

Existing Facility 

Units 1 and 3, 

tons/yr

Reductions from 

1994/1995 Baseline, tons/yr (10% 

reduction) 

Proposed Facility 

Units 1, 2, and 3, 

tons/yr

NOx 4,000 400 3,600

SO2 13,649 1,365 12,284

Particulate Matter 979 98 881

CO -- -- 3,066

VOC (computed as 

4% of CO) -- -- 123

SO2 Emissions

Annual Energy Output

NOx Emissions

PM Emissions

13,649 6.3

12,284

2.3

4,000

979

3,600

881

Before Repowering After Repowering

Energy Output - Million MWh/yr

Emissions - 

Tons/yr

8.0

7.0

6.0

5.0

4.0

3.0

2.0

1.0

0.0

16,000

14,000

12,000

10,000

8,000

6,000

4,000

2,000

0

Comparison of anticipated annual energy output and emissions before and after 

repowering

Fuel storage dome under construction
10 

Ash Handling System

The ash handling system transports bed ash from the 

outlets of the stripper coolers to the bed ash silos, and 

fl y ash from the economizer, air heater hoppers, and 

baghouse hoppers to the fl y ash silos. Two sets of ash 

handling systems and associated equipment are provided, 

one for Unit 1 and the other for Unit 2. The bed ash mechanical conveying system and fl y ash vacuum conveying 

system in turn consist of two fully independent parallel 

lines. Normally any one line is in operation and the other is 

an installed spare; however, in an emergency upset condition, both lines can be operated simultaneously.

The bed ash and fl y ash from the ash silos is slurried 

using reclaimed water, mixed together, and pumped as a 

dense slurry to the by-product storage area.

Reuse Water System

Reuse water is domestic wastewater that has been 

treated and disinfected to a high degree and reused for 

benefi cial purposes. The reuse water used at Northside 

Generating Station is obtained from the District II Water 

Reclamation Facility, transported via an eight-mile pipeline. The wastewater is treated through primary, secondary and advanced treatment. During primary treatment, 

large solids are removed. Secondary treatment uses microorganisms to remove the remaining solids and organic 

material.

After secondary treatment, the wastewater travels 

through cloth membrane fi lters, with a pore size of approximately 10 microns, to remove virtually all remaining 

solids. During advanced or fi nal treatment, the wastewater is disinfected using chlorine or ultraviolet light to destroy bacteria, viruses and other pathogens.

Consumption of reuse water is expected to be more 

than 1 million gallons/day when all three units are operating. The reuse water is used for circulating water 

pump seals, boiler/precipitation area drains, polishing 

scrubbers, ash slurry preparation, and fuel handling dust 

suppression and wash down. Future uses may include 

irrigation.

Limestone preparation system
11

Project History

DOE selected the Large-Scale CFB Combustion Demonstration Project in June 1989 

as part of Round I of the CCT Program. After 

a number of host sites were considered, the 

project was resited in August 1997 to Jacksonville, Florida. The Cooperative Agreement 

was signed in September 1997.

The Environmental Impact Statement 

for the Jacksonville site, as required by the 

National Environmental Policy Act, was 

completed in December 2001.

JEA Background

JEA is the largest municipal power 

company in Florida and the eighth largest 

municipal utility in the United States. JEA 

currently serves nearly 350,000 customers 

and is experiencing a load growth rate of more 

than 3% per year. Most municipal utilities in 

the United States do not generate their own 

power. Those that do so are relatively small, 

generating 25 MWe or less. Many of these 

small utilities use diesel engines for power 

generation. JEA is one of very few municipal 

utilities having an installed capacity of greater 

than 300 MWe.

Prior to the Large-Scale CFB Demonstration Project, JEA’s Northside Station consisted 

of three oil/gas fi red steam electric generating 

units. Units 1 and 2 were each nominally 

rated at 275 MWe and Unit 3 at 518 MWe. 

Units 1 & 3 had been in service since 1966 

and 1977 respectively. Unit 2 was completed 

in 1972, but had been inoperable since about 

1983 due to major boiler problems.

As part of its Integrated Resource Planning 

Study in 1996, JEA concluded that additional 

base load capacity was needed to support 

Jacksonville’s growing need for energy. 

With demand growing, JEA executives saw 

that the utility’s ability to generate all of the 

electricity required by its customers—something JEA had done for 100 years—would be 

compromised early in the 21st century unless 

it soon began planning new facilities.

The optimum source for that additional 

capacity was determined to be repowering 

Unit 2 with a state-of-the-art ACFB boiler 

fueled by coal fuel blends. To provide the 

project with an overall environmental benefi t, 

increase the economies of scale, and further 

diversify JEA’s fuel mix, a decision was made 

to repower Unit 1 with an identical ACFB 

boiler as well. The DOE cost sharing does 

not cover the Unit 1 repowering.

The environmental benefi ts include a 

reduction in emissions of NOx, SO

2

, and 

particulate matter by at least 10% compared 

to 1994/1995 levels. As a result of increased 

generating capacity and improved capacity 

factor, total power production was planned 

to increase from about 2.3 million MWh/yr 

to about 6.3 million MWh/yr, an increase of 

about 170%. An additional economic benefi t 

results from the fact that, prior to the repowering project, Units 1 and 3 fi red relatively 

high cost fuels, resulting in limited dispatch 

of these units. As a result of the repowering, 

both Unit 1 and Unit 2 are now capable of 

fi ring relatively low cost solid fuels. The use 

of these fuels, which can be delivered by 

ship, takes full advantage of JEA’s existing 

strategic assets including access to the St. 

Johns River.

continued on page 14
12 

Process Flowsheet

Coal or coal fuel blends are crushed to about 1⁄4 inch diameter 

and mixed with limestone crushed to the size of sand. The fuel is 

gravimetrically metered and swept with heated combustion air into 

the base of the combustor. Limestone is injected into the same area 

of the combustor by the use of positive displacement blowers.

As the solid mixture rises, it ignites and begins a controlled 

“slow burn.” The slow burn process maintains temperatures below 

1600°F across a large area, minimizing the production of pollutants. 

At temperatures above 1600°F, production of NOx increases significantly.

As the fuel particles burn, they become lighter and, with the help 

of additional air that constantly turns the particles over in a fluid-like 

motion, they are carried higher in the combustor. The limestone absorbs about 90% of the sulfur in the fuel (as SO2).

At the cyclone inlet located at the top of the combustor, aqueous ammonia is injected into the flue gas to further reduce NOx 

produced in the furnace, converting it to molecular N2. The cyclones 

provide for efficient mixing of the flue gas and ammonia as well as 

sufficient residence time at the optimum operating temperature for 

effective NOx reduction.

The hot ash and limestone pass through the INTREXTM exchanger before being recycled to the bottom of the combustor. In 

the INTREXTM exchanger, superheated steam is produced in tubes 

over which the hot ash returning to the combustor flows.

The steam flows into the cyclone inlet panels, through the cyclone walls, into the convection cage wall, through the primary 

superheater, and into the intermediate and finishing superheaters 

which reside within the INTREXTM exchanger. Solid material, consisting primarily of ash and CaSO4, is removed from the bottom of 

the combustor and sent to by-product storage.

The hot gases leaving the top of the cyclone enter additional 

reheater/superheater tubes that also generate steam for the turbines. The still hot flue gas is used to preheat the main combustion 

air before it is introduced to the bottom of the furnace.

After the reheater/superheater, the flue gas enters an air quality control system, where it travels downward through a polishing 

scrubber that applies a lime slurry to absorb SO2. Following the 

scrubber, the flue gas passes through a baghouse containing fabric 

filters to further clean the gas before it is sent up the stack. The collected particulates, which are sent to by-product storage, include 

trace metals captured in the fabric filters.

S

Coal/Coke

Air

High Pressure Steam

Lower Pressure Steam

Water

Particulate

Lime Slurry

To B

Secondary

Air

F

Limestone

Air 

Botto

Ash

JEA Large-
13

Steam Turbine

Generator

Polishing

Scrubber

Steam

Steam

Intrex

Lime

Slurry

Heated

Air to

Boiler

Byproduct Storage

Particulate

Control

Device

Stack

To Byproduct Storage Condenser

Circulating

Fluidized-Bed Boiler

Cyclone

Reheat

Exchanger

Economizer

Air Preheater

r Air

om

h

Feed Water

Air

-Scale CFB Combustion Demonstration Project

Ammonia

Injection
14 

Natural gas was rejected as an option 

because northeastern Florida was served by 

only one pipeline at that time. Orimulsion was 

not considered seriously because it was not 

held in high regard by regulatory authorities 

and it did not offer a cost advantage.

In early 1997, detailed condition assessments of Unit 1 and Unit 2 BOP equipment 

and systems were conducted by JEA and 

Black & Veatch. The results of that study 

indicated that both Unit 1 and Unit 2 were 

good candidates for repowering and were 

capable of operating for many more years, 

provided various equipment and system 

upgrades were made.

In April 1997, JEA approved the project 

and authorized staff to begin working with 

Foster Wheeler (FW) on contract negotiations 

and environmental permitting.

Project Organization

JEA contracted with Foster Wheeler 

Energy Corporation (FWEC) to provide 

the design and supply of the ACFB boilers. 

Foster Wheeler USA (FWUSA) provided 

engineering, procurement, and construction 

management services for installation of the 

boilers and for furnishing and erecting the air 

pollution control systems, stack, limestone 

preparation system, and ash handling system. 

Foster Wheeler Environmental Corporation, a 

subsidiary of FWUSA, was also contracted to 

provide environmental permitting services.

The remaining portions of the project were 

implemented by JEA staff, supplemented by 

Black & Veatch through a pre-existing alliance with JEA for engineering services. Procurement, construction and related services 

were provided through other pre-existing 

Fluidized Bed Combustion

Fluidized bed combustion (FBC) is one of the major technologies being developed under Advanced Electric Power Generation in DOE’s CCT Program. 

FBC reduces emissions of SO2 and NOx by controlling combustion parameters and by injecting a sorbent, such as crushed limestone, into the combustion chamber along with the coal.

Pulverized coal mixed with the limestone is fluidized on jets of air in the 

combustion chamber. Sulfur released from the coal as SO2 is captured by the 

sorbent in the bed to form a solid calcium compound that is removed with the 

ash. The resultant by-product is a dry, benign solid that can be disposed of 

easily or used in agricultural and construction applications. More than 90% of 

the SO2 can be captured in this manner.

At combustion temperatures of 1,400 to 1600°F, the fluidized mixing of the 

fuel and sorbent enhances both combustion and sulfur capture. The operating temperature range is much lower than that of a conventional pulverizedcoal boiler and below the temperature at which thermal NOx is formed. In 

fact, NOx emissions from FBC units are about 70 to 80% lower than those for 

conventional boilers. Thus, FBC units substantially reduce both SO2 and NOx 

emissions. Also, FBC has the capability of using high-ash coal, whereas conventional pulverized-coal units must limit ash content in the coal to relatively 

low levels.

Two parallel paths have been pursued in FBC development—bubbling and 

circulating beds. Bubbling FBCs use a dense fluid bed and low fluidization 

velocity to effect good heat transfer and mitigate erosion of an in-bed heat 

exchanger. Circulating FBCs use a relatively high fluidization velocity that entrains the bed material, in conjunction with hot cyclones, to separate and recirculate the bed material from the flue gas before it passes to a heat exchanger. 

Hybrid systems have evolved from these two basic approaches.

Fluidized bed combustion can be either atmospheric (AFBC) or pressurized 

(PFBC). As implied by the name, AFBC operates at atmospheric pressure. 

PFBCs, which operate at pressures 6 to 16 times higher, offer higher efficiency by expanding the hot combustion products through a gas turbine and 

utilizing the steam generated within the combustor to operate a steam turbine. 

Consequently, operating costs and waste are reduced relative to AFBC, as 

well as boiler size per unit of power output.

Second-generation PFBC integrates the combustor with a pyrolyzer (coal 

gasifier) to fuel a gas turbine (topping cycle), and the waste heat is used to 

generate steam for a steam turbine (bottoming cycle). The inherent efficiency 

of the gas turbine and waste heat recovery in this combined-cycle mode significantly increases overall efficiency. Such advanced PFBC systems have the 

potential for overall thermal efficiencies approaching 50%.

Since PFBCs have not yet been demonstrated on a commercial scale, 

AFBCs were chosen for the JEA project.
15

alliances between JEA and Zachry Construction Corporation, Fluor Global Services, 

W.W. Gay Mechanical Contractor, Inc., and 

Williams Industrial Services Inc. This work 

included upgrades of the existing turbine island equipment, construction of the receiving 

and handling facilities for the fuel and reagent 

required for solid fuel fi ring, upgrading of the 

electrical switchyard facilities, and construction of an ash management system.

Project Status

Environmental permitting work was initiated by FW in the latter part of 1997. This 

work and associated preliminary engineering proceeded through 1998 and into early 

1999. FW began detailed engineering for 

the boiler island, including the air quality 

control system, stack, and limestone preparation system, in December 1998. Black & 

Veatch began detailed engineering for BOP 

systems, including the fuel handling system, 

in February 1999. Permits necessary to begin 

construction were issued in July 1999, with 

site clearing and construction beginning in 

August 1999.

Initial synchronization was achieved for 

Unit 2 on February 19, 2002, and for Unit 

1 on May 29, 2002. The JEA project will 

include two years of demonstration test runs, 

during which a variety of coal fuel blends 

will be fi red.

Design Parameters

Fuel Specifi cations Coal Petroleum Coke

Heating Value, Btu/lb >11,600 >13,000

Sulfur, % 0.5-4.5 3.0-8.0

Ash, % 7-15 <3

Volatile Matter, % 30-60 >7

Steam Flow and Conditions Reheat Main 

Flow, 1000 lb/hr 1994 1773

Pressure, psi 2,500 548

Temperature, °F 1,000 1,000

JEA plant view from by-product storage area
16 

Project Objectives

The JEA project objectives are (1) to 

demonstrate ACFB technology at 297.5 

MWe gross (265 MWe net), representing 

a scale-up from previously constructed 

facilities; (2) to verify expectations of the 

technology’s economic, environmental, and 

technical performance to provide potential 

users with the data necessary for evaluating 

large-scale ACFBs as a commercial alternative; (3) to accomplish greater than 90% SO2

removal; and (4) to reduce NOx emissions 

by 60% compared with conventional pulverized-coal (PC) fi red boilers not equipped with 

post-combustion NOx removal.

Initial Performance Results

Emissions Guarantee Value 100% Coal Test 100% Coke Test

SO2, lb/106 Btu <0.15 0.00-0.04 0.03-0.13

NOx, lb/106 Btu <0.09 0.04-0.06 0.02

CO, lb/106 Btu <0.22 0.044-0.054 0.013-0.015

Particulates, lb/106 Btu <0.011 0.004 0.007

PM10, lb/106 Btu <0.011 0.006 0.0044

SO3, lb/hr 1.1 0.43 0.00

Fluoride, lb/hr 0.43 0.29 0.261

Lead, lb/hr 0.070 0.015 0.016

Mercury, lb/hr 0.03 0.0027 0.0008

VOC, lb/hr 14.0 <0.1 <0.1

Opacity, % <10 0.36-1.12 0.21-2.64

Ammonia Slip, ppm 40 0.9 n/a

Boiler Parameters

Steam Flow, 1000 lb/hr >1794 1950 1937

Main Steam Temperature, °F >980 996 992

Reheat Steam Temperature, °F >980 1001 993

Main Steam - Reheat Steam Temperature, °F <30 6 5

Boiler Effi ciency, % 81.8 88.2 92.0
17

Project Scope

The JEA project involves the construction and operation of a new 300-MWe ACFB 

boiler fi red with coal fuel blends to repower 

an existing steam turbine. ACFB boilers are 

capable of removing about 90% of the SO2

generated, using limestone at a design Ca/S 

ratio of < 2/1. Greater percentage removal can 

be achieved by increasing the Ca/S ratio, but 

the added cost for limestone sorbent becomes 

prohibitive. To optimize the overall economics and to meet environmental requirements, 

a polishing scrubber was included in the JEA 

project. This added feature is required when 

fi ring higher sulfur fuels, including petroleum 

coke containing up to 8.0% sulfur.

A key feature of the polishing scrubber 

is a recycle system which adds fl y ash to the 

lime sorbent, thereby taking advantage of the 

unreacted lime in the fl y ash to reduce the 

amount of fresh lime required. The resulting 

savings in sorbent and ash disposal costs offset the added capital and operating costs for 

the scrubber. In addition, the scrubber offers 

reductions in emissions of trace elements. 

The JEA installation represents the fi rst use 

of a polishing scrubber in conjunction with 

a CFB in the United States.

As indicated previously, the project 

includes an SNCR system to reduce NOx 

emissions to the very low levels required. A 

new baghouse was installed to achieve over 

99.8% reduction in particulate emissions.

In addition to the ACFB combustor itself 

and the air pollution control systems, new 

equipment for the project includes an approximately 500-ft high stack as well as handling 

systems for fuel, limestone, and ash. This 

includes facilities for delivery of solid fuel 

to the site by ship. The project also required 

overhaul and/or modifi cations of existing systems such as the steam turbines, condensate 

and feedwater systems, circulating water systems, water treatment systems, plant electrical 

distribution systems, the switchyard, and the 

plant control systems.

A signifi cant aspect of the JEA project design is that many of the boiler components are 

at the leading edge of technology, but have been 

applied successfully in commercial service at 

least once before. Integrating all these components while signifi cantly scaling up boiler size 

is a major project accomplishment.

Wherever possible, existing facilities and 

infrastructure were used. These include the 

intake and discharge system for cooling water, the wastewater treatment system, and the 

electric transmission lines and towers.

Project activities include engineering 

and design, permitting, procurement, construction, startup, and a twenty-four month 

demonstration of the commercial feasibility 

of the technology. During the demonstration test program, Unit 2 will be operated 

on several different types of coal fuel blends 

to enhance the viability of the technology. 

Upon completion of the demonstration test 

program, Unit 2 will continue in commercial 

operation. As long as petroleum coke is less 

expensive than coal, it will continue to be the 

preferred fuel for the JEA plant.

JEA plant with ship unloading dock in foreground

Fuel unloader at dock
18 

Advantages of CFB Boilers

Combustion efficiency is improved 

in circulating fluidized bed (CFB) 

boilers compared to bubbling bed 

boilers. This is primarily because 

the elutriated particles are separated from the flue gas in cyclone 

collectors (hot cyclones with vortex 

finders) and returned to the furnace 

for further exposure to combustion 

temperature and high turbulence. 

This fact results in an increase of 

up to 4% in overall combustion efficiency. The particles captured in 

the cyclone collectors make up the 

circulating bed material within the 

“hot loop.” The hot loop is a term 

given for the circulating path of 

bed material inside the boiler.

Other advantages of CFB boilers 

over conventional PC-fired boilers 

are:

• Lower capital cost

• Ability to burn a wide range of lowto high-grade fuels

• Increased sulfur capture with less 

limestone consumption and low 

SO2 emissions

• Lower operating temperatures 

compared with other types of boilers, thereby reducing slag formation and excess stack emissions

• Improved heat transfer with the 

increase in residence time for fuel 

and limestone

• Lower NOx emissions because of 

low operating temperatures

Lower operating temperatures 

mean fewer pollutants and less 

equipment needed to clean up the 

combustion process while burning a 

variety of fuels. The ratios between 

operating gas velocity and minimum 

solids entrainment velocity allow 

turndown ratios as high as four to 

one. Operation over a wide range of 

boiler loads is possible without starting and stopping burners and auxiliary equipment.

Schematic diagram of CFB boiler at JEA
19

in the fuel. Incomplete combustion results 

in the formation of carbon monoxide (CO) 

plus unburned carbon in the solid particles 

leaving the furnace. In a typical bubbling bed 

fl uidized boiler, combustion effi ciency can be 

as high as 92%. This is a good fi gure, but is 

lower than that achieved by pulverized coal or 

cyclone-fi red boilers. In addition, some fuels 

that are very low in volatile matter cannot be 

completely burned within the available residence time in bubbling bed-type boilers.

Circulating Fluidized Bed Boilers

The need to improve combustion effi -

ciency (which also increases overall boiler 

effi ciency and reduces operating costs) and 

the desire to burn a much wider range of fuels 

has led to the development and application 

of the CFB boiler. Through the years, boiler 

suppliers have been increasing the size of 

these high-effi ciency steam generators. FW 

has designed (but not built) CFB boilers 

that are capable of producing 400 MWe of 

power.

Fluidized Bed 

Combustion 

Systems

The ACFB boiler technology selected 

for the JEA project is an advanced method 

for utilizing coal and other solid fuels in an 

environmentally acceptable manner. The low 

combustion temperature allows SO

2

 capture 

via limestone injection while minimizing 

NOx emissions. The technology provides 

the capability to burn a wide range of coal 

fuel blends. Presently, there are two types of 

fl uidized bed boilers in commercial operation: 

bubbling bed and circulating bed.

Bubbling Bed Boilers

In the bubbling bed type boiler, a layer of 

solid particles (mostly limestone, sand, ash 

and calcium sulfate) is contained on a grid 

near the bottom of the boiler. This layer is 

maintained in a turbulent state as low velocity air is forced into the bed from a plenum 

chamber beneath the grid. Fuel is added to this 

bed and combustion takes place. Normally, 

raw fuel in the bed does not exceed 2% of the 

total bed inventory. Velocity of the combustion air is kept at a minimum, yet high enough 

to maintain turbulence in the bed. Velocity is 

not high enough to carry signifi cant quantities 

of solid particles out of the furnace.

This turbulent mixing of air and fuel results 

in a residence time of up to fi ve seconds. 

The combination of turbulent mixing and 

residence time permits bubbling bed boilers 

to operate at a furnace temperature below 

1650°F. At this temperature, the presence 

of limestone mixed with fuel in the furnace 

achieves greater than 90% sulfur removal.

Boiler effi ciency is the percentage of total 

energy in the fuel that is used to produce 

steam. Combustion effi ciency is the percentage of complete combustion of carbon 

CFB boiler under construction

continued on page 21
20 

The Clean Coal Technology Program

The Clean Coal Technology 

(CCT) Program is a unique partnership between the federal government and industry that has as its 

primary goal the successful introduction of new clean coal utilization 

technologies into the energy marketplace. With its roots in the acid rain 

debate of the 1980s, the program 

has met its early objective of broadening the range of technological 

solutions available to eliminate environmental concerns associated with the use of coal 

for electric power 

production. As 

the program has 

evolved, it has 

expanded to address the need for 

new, high-efficiency 

power generating 

technologies that will 

allow coal to continue to 

be a fuel option well into the 

21st century.

Begun in 1985 and expanded in 

1987 consistent with the recommendations of the U.S. and Canadian 

Special Envoys on Acid Rain, the 

program has been implemented 

through a series of five nationwide 

competitive solicitations, or rounds. 

Each solicitation was associated 

with specific government funding 

and program objectives. After five 

rounds, the CCT Program comprises 

a total of 38 projects located in 18 

states with a total investment value 

of over $5.2 billion. DOE’s share 

of the total project costs is about 

$1.8 billion, or approximately 34% 

of the total. The projects’ industrial 

participants (i.e., the non-DOE participants) are providing the remainder—about $3.5 billion.

Processes being demonstrated under the CCT Program have established 

a technology base that will enable the 

nation to meet more stringent energy 

and environmental goals. Also ready is 

a new generation of technologies that 

can produce electricity and other commodities, such as steam and synthesis 

gas, at high efficiencies consistent with 

concerns about global climate change.

Most of the CCT demonstrations are 

being conducted at commercial scale, 

in actual user environments, and under 

circumstances typical of commercial 

operations. These features allow the 

potential of the technologies to be 

evaluated in their intended commercial 

applications.

Each application addresses one of 

the following four market sectors:

• Advanced electric power generation

• Environmental control devices

• Coal processing for clean fuels

• Industrial applications

Given its programmatic success, the 

CCT Program serves as a model for 

other cooperative government/industry 

programs aimed at introducing new 

technologies into the commercial 

marketplace.

Two follow-on programs have 

been developed that build on the 

successes of the CCT Program. The 

Power Plant Improvement Initiative 

(PPII) is a cost shared program, patterned after the CCT Program, directed toward improved reliability and 

environmental performance of the 

nation’s coal-burning power 

plants. Authorized by 

the U.S. Congress 

in 2001, the PPII 

involves eight 

projects having a total cost 

of $95 million. 

Private sector 

sponsors are 

expected to 

contribute nearly 

$61 million, exceeding the 50% private sector cost sharing mandated by 

Congress. Most of the PPII projects 

focus on technologies enabling 

coal-fired power plants to meet increasingly stringent environmental 

regulations at the lowest possible 

cost.

The second program is the Clean 

Coal Power Initiative (CCPI), also 

patterned on the CCT Program, 

authorized in early 2002. Valued 

at $330 million for the initial stage, 

this initiative will accelerate the 

commercial deployment of technology advancements that result 

in efficiency, environmental and 

economic improvement compared 

with available state-of-the-art alternatives. Proposals submitted 

under the CCPI are currently being 

evaluated.
21

CFBs offer a number of advantages:

Fuel Flexibility – The relatively low furnace temperatures are below the ash softening 

temperature for nearly all fuels. As a result, 

furnace design is independent of ash characteristics, thus allowing a given furnace to 

handle a wide range of fuels.

Low SO2 Emissions – Limestone is an 

effective sulfur sorbent in the temperature 

range of 1500 to 1700°F. SO2 removal effi ciency of 90% has been demonstrated with 

good sorbent utilization.

Low NOx Emissions – The combination 

of low furnace temperatures and staging of 

air feed to the furnace produces very low 

NOx emissions.

High Combustion Effi ciency – The long 

solids residence time in the furnace resulting 

from the collection/recirculation of solids via 

the cyclone, plus the vigorous solids/gas contact in the furnace caused by the fl uidization 

air fl ow, results in high combustion effi ciency, 

even with diffi cult-to-burn fuels.

Characteristics of CFB Boilers

In the furnace of a circulating fl uidized bed 

boiler, gas velocity is increased to more than 

that in a bubbling bed boiler. This increase in 

velocity causes the dense mixture of solids 

(fuel, limestone and ash) to be carried up 

through the furnace. There is a minimum gas 

entrainment velocity required for the particles 

to lift and separate (elutriate) and fl ow up, 

through and out of the furnace.

Reaching this entrainment velocity marks 

the change from a bubbling bed boiler to a circulating bed boiler. At approximately 500°F 

bed temperature, air fl ows are above minimum 

and the entrainment velocity is reached.

Solids move up through the furnace at 

lower velocities than the air and gas mixture. 

This fact, coupled with the elongated furnace 

in a CFB boiler and recirculating bed material, 

allows particle residence times of up to several minutes in the furnace. During this long 

residence period, the crushed fuel particles New 500-foot stack in foreground, with inset showing the stack interior

are consumed in the combustion process.

The fuel is reduced in size during the combustion process and thoroughly mixed with 

limestone and the balance of the bed material. 

This action produces the “fi nes” (small particles 

of bed material) necessary to have circulating 

bed material in the “hot loop.” Long residence 

time, coupled with small particle size and high 

turbulence, results in a better sulfur removal 

rate with less limestone than in a bubbling 

fl uidized bed boiler. In addition, higher gas 

velocity produces heat transfer rates that are 

greater than in the bubbling bed.

In normal operation there is no defi ned fi xed 

bed depth in a CFB boiler. There are different 

densities of circulating bed material depending 

on the weight of the particles. Heavy particles 

stay in the lower region of the furnace. As the 

height within the furnace increases, the smaller 

bed particles (less dense) enter the circulation 

path of the hot loop. When the particles break 

down enough, they are carried out of the hot 

loop (circulating path) with the fl ue gas as 

fl y ash.
22 

Sulfur Removal in CFB Boilers

Most of the sulfur in the fuel combines 

chemically with oxygen during the combustion process to form SO2

 and, to a limited 

extent, sulfur trioxide (SO3). These sulfur 

oxides must be removed from the fl ue gas 

to comply with environmental regulations.

The mechanism for removing SO2 with 

limestone is as follows:

Calcination of limestone:

CaCO3 + Heat  CaO + CO2

Reaction with sulfur oxides (sulfation):

CaO + O2 + SO2  CaSO4

The product, CaSO4, is an inert substance 

known as gypsum. Limestone continuously 

reacts with the fuel at normal operating temperatures. The sulfation reaction requires that 

there always be an excess of limestone. The 

amount of excess limestone required depends 

on several factors, such as the amount of sulfur 

in the fuel, the temperature of the bed material 

in the furnace, and the physical and chemical 

characteristics of the limestone (reactivity). 

The ideal reaction temperature range is 1500 

to 1700°F.

There is little limestone reaction when the 

bed temperature is below 1500°F or above 

1700°F. Within the optimum temperature 

range, about 90% of the SO2 can be removed at an acceptable Ca/S ratio. Outside 

this temperature range, signifi cant increases 

in limestone feed rate are required to maintain 

emission levels within regulated limits.

The CFB bed material typically contains 

limestone products as the predominant component, with smaller amounts of fuel, ash and 

impurities (for example, rocks or tramp iron). 

Calcium oxide content rises with decreasing 

fuel sulfur content and high removal rates. The 

ash content increases with higher ash fuels 

and those that are less friable, i.e., brittle.

Fresh limestone enters the furnace and, at 

the normal operating temperature, calcines 

by liberating CO2. It then absorbs SO2 from 

the burning fuel that sulfates the limestone, 

converting limestone to gypsum. In the calcining stage, limestone is physically weak and 

is easily decrepitated (crumbled) into dust 

and carried out of the bed (elutriated) by the 

furnace draft.

With a sulfur content in the fuel of 2.5% or 

more, enough SO2 is produced during combustion that the limestone can readily sulfate 

(combine with the SO2). This strengthens the 

limestone and reduces loss of limestone from 

decrepitation and elutriation. A low sulfur 

content can lead to loss of limestone through 

attrition. This loss must be compensated for 

by increasing limestone feed to maintain bed 

inventory and SO2 capture. Gypsum and some 

excess limestone are carried out of the CFB 

furnace and trapped by the downstream fl ue 

gas cleanup equipment.
23

Demonstration 

Test Program

The demonstration test program will 

be conducted in accordance with the plan 

developed in coordination with DOE. The 

test program consists of the following major 

components.

Operational Testing will be performed to:

• Demonstrate unit functionality

• Establish initial operating, maintenance 

and inspection criteria

• Establish constraints related to dispatch of 

the unit

• Demonstrate continuous full- and part-load 

capability and performance

Operational testing includes a series of operability, reliability, and performance tests.

Operability involves tests of cold startups, 

warm startups, hot restarts, dispatch, minimum stable load, and operation at maximum 

continuous rating.

Reliability testing includes availability, 

capacity factor, and forced outage rate.

Performance testing will be conducted 

in conjunction with fuel fl exibility testing, 

which involves burning four different fuels 

and fuel blends. The specifi c fuels to be tested 

are as follows: • 100% Pittsburgh No. 8 high-sulfur coal • 90% petroleum coke and 10% Pittsburgh 

No. 8 high-sulfur coal

• 50% petroleum coke and 50% Pittsburgh 

No. 8 high-sulfur coal

• 100% Illinois No. 6 high-sulfur coal

Fuel Flexibility Testing includes boiler 

capacity and controllability, load following capability, bed/cyclone agglomeration 

potential, and air quality control system 

performance.

Long Term Durability Testing consists 

of reviewing signifi cant maintenance issues 

experienced with major equipment throughout the demonstration period.

Operating Results

The JEA Unit 2 CFB boiler has operated at 

full load, achieving rated output in May 2002. 

The unit can maintain operation on both coal 

and coal fuel blends. However, satisfactory 

operation on 100% petroleum coke has not 

yet been demonstrated. One major problem 

when operating on 100% petroleum coke has 

been plugging in the hot gas path, specifi -

cally in the cyclone and the INTREXTM heat 

exchanger. Steps are being taken to remedy 

this situation.

Initial results indicate that the JEA plant is 

capable of meeting emissions guarantees when 

operating on both coal and coal fuel blends.

Interior of fuel storage dome
24 

Awards

The JEA project received the 2002 Powerplant Award from Power magazine. This 

award recognizes outstanding achievement in 

“the development of a successful repowering 

strategy for converting existing oil/gas-fi red 

steam plants to solid fuels to increase effi -

ciency while reducing both emissions and 

the cost of electricity.”

Bob Dyr, JEA’s Boiler Island Project Manager, was presented the Engineer of the Year 

award by the Florida Engineers Society in 

2002 for outstanding technical achievement, 

on behalf of the project team.

Commercial 

Applica tions

ACFB technology has potential application in both the industrial and utility sectors, 

for use in repowering existing plants a well as 

in new facilities. ACFB is attractive for both 

baseload and dispatchable power applications 

because it can be effi ciently turned down to as 

low as 25% of full load. While the effi ciency 

of ACFB is on a par with conventional PCfi red plants, the advantage of ACFB is that 

coal of any sulfur or ash content can be used, 

and any type or size unit can be repowered. 

In repowering applications, an existing plant 

area is used, and coal- and waste-handling 

equipment as well as steam turbine equipment are retained, thereby extending the life 

of the plant.

In its commercial confi guration, ACFB 

technology offers several potential benefi ts 

compared with conventional PC-fi red systems:

• Lower capital costs

• Reduced SO2 and NOx emissions at lower 

cost

• Higher combustion effi ciency

• A high degree of fuel fl exibility, including 

use of renewable fuels

• Dry, granular solid by-product material 

that is easily disposed of or sold.

Recently, two other commercial scale 

ACFB projects in the U.S. have been announced, one at Reliant Energy's Seward 

Station in Pennsylvania and the other at 

Tractabel's Red Hills Station in Mississippi.

Conclusions

The JEA Large-Scale CFB Combustion 

Demonstration Project is demonstrating the 

commercial ap plication of this advanced 

technology for generating electricity. The 

two boilers at the Northside Station are the 

largest CFBs in the world burning coal fuel 

blends. Despite the large furnace size, solids 

distribution is good, lending confi dence to the 

CFB design.

Power production from each boiler on coal 

feed meets the target goal of 297.5 MWe gross 

(265 MWe net). Emissions of atmospheric pollutants are below the stringent requirements 

set for the project.

JEA receives the Power magazine 2002 

Powerplant award. On hand for the award 

ceremony were (left to right): Mike Hightower, JEA's Board Chairman; Joey Duncan, JEA's Project Manager; the Honorable 

Corrine Brown, U.S. House of Representatives; Rita Bajura, Director of U.S. DOE's 

National Energy Technology Laboratory; 

and Bob Schwieger, Power magazine consulting editor
25

Bibliography

P.T. Nielsen, J.L. Hebb, R. Aquino, and 

S.L. Darling, “Large-Scale CFB Combustion Demonstration Project,” Sixth Clean 

Coal Technology Con ference (Reno NV), 

May 1998.

U.S. Department of Energy, Clean Coal Technology Demonstration Program -- Program 

Update 2000, July 2002.

R. Dyr and G. Graham, “The Northside 1 

and 2 Repowering Project: An Overview,” 

7th Foster Wheeler Fluidized Bed Customer 

Conference, San Diego CA, August 14-16, 

2002.

R. Schwieger, “Northside’s CFB Repowering Halves Power Cost, Reduces Emissions,” 

Power, September 2002, p. 20.

R.A. Dyr and A.L. Compaan, “JEA Northside 

Repowering: 2002 Powerplant of the Year,” 

presented at FMEA 2002 Energy Connections 

Workshop and Trade Show, St. Petersburg 

FL, October 15-17, 2002.

JEA, “Public Design Report for the JEA 

Large-Scale CFB Combustion Demonstration Project,” March 2003.
26 

List of Acronyms and Abbreviations

ACFB ........................... atmospheric circulating fl uidized bed

AFBC ........................... atmospheric fl uidized bed combustor

AQCS........................... air quality control system

BOP.............................. balance of plant

Btu................................British thermal unit

CaCO3 .......................... calcium carbonate

CaO .............................. calcium oxide

Ca(OH)2........................ calcium hydroxide

CaSO4 ........................... calcium sulfate

CAAA...........................Clean Air Act Amendments of 1990

CCPI.............................Clean Coal Power Initiative

CCT..............................Clean Coal Technology

CFB.............................. circulating fl uidized bed

CO2 ............................... carbon dioxide

CRT .............................. cathode ray tube

DCS.............................. distributed control system

DOE ............................. U.S. Department of Energy

EPA............................... U.S. Environmental Protection Agency

FBC.............................. fl uidized bed combustion

FF .................................fabric fi lters

Stack shortly after 9/11/2001
27

kWh.............................. kilowatt hour

micron .......................... one millionth of a meter

MCR.............................maximum continuous rating

MgCO3 .........................magnesium carbonate

Mg(OH)2 ......................magnesium hydroxide

MWe.............................megawatts of electric power

MWh ............................megawatt hours of electric power

NETL............................ National Energy Technology Laboratory

NOx.............................. nitrogen oxides

PC................................. pulverized coal

PFBC............................ pressurized fl uidized bed combustor

PLC .............................. programmable logic controller

PM................................ particulate matter

PM10 ............................. particulate matter having a diameter of 10 microns (μm) or less

PPII............................... Power Plant Improvement Initiative

psig ............................... pressure, pounds per square inch (gauge)

SDA..............................spray dryer absorber

SO2 ...............................sulfur dioxide

SO3 ...............................sulfur trioxide

tph................................. tons/hr

VOC ............................. volatile organic compound

wt % ............................. percent by weight

Sunset at JEA
28

Contacts for CCT 

Projects and 

U.S. DOE CCT 

Program

Participant Contact

Joey V. Duncan

JEA Project General Manager

(904) 714-4831

duncjv@jea.com

U.S. Department of Energy Contacts

George Lynch

U.S. Department of Energy, FE-24

Germantown MD 20874-1290

(301) 903-9434

(301) 903-2713 fax

george.lynch@hq.doe.gov

Jerry L. Hebb, P.E.

Project Manager

National Energy Technology Laboratory

P.O. Box 10940

Pittsburgh PA 15236-0940

(412) 386-6079

(412) 386-4775 fax

jerry.hebb@netl.doe.gov

This report is available on the Internet at 

www.netl.doe.gov. Select Links, then Clean 

Coal Technology Compendium

NETL web page on FBC:

www.netl.doe.gov/coalpower/combustion

JEA website:

www.jea.com

To Receive Additional 

Information

To be placed on the Department 

of Energy’s distribution list for future 

information on the Clean Coal Technology Program, the demonstration projects it is financing, or other 

Fossil Energy Programs, please 

contact:

Robert C. Porter

Director, Office of Communication

U.S. Department of Energy, FE-5

1000 Independence Ave SW

Washington DC 20585

(202) 586-6503

(202) 586-5146 fax

robert.porter@hq.doe.gov

Otis Mills

Public Information Office

U.S. Department of Energy

National Energy 

 Technology Laboratory

P.O. Box 10940

Pittsburgh PA 15236-0940

(412) 386-5890

(412) 386-6195 fax

otis.mills@netl.doe.gov