7/28/2019 1650167

1/75

DOE/MC/27403 -- 5242(DE96011321)

250 M W Single Train CFB Cogeneration Facility

Annual ReportOctober 1993 - September 1994

February 1995Work Performed Under Contract No.: DE-FC21-91MC27403

ForU.S. Department of EnergyOffice of Fossil EnergyMorgantown Energy Technology CenterMorgantown, West Virginia

BYYork County Energy Partners, L.P.25 South Main StreetSpring Grove, Pennsylvania 17362* ~~~~~~~~~~~ OF INS ~~~~~

7/28/2019 1650167

2/75

Disclaimer

This report was prepared as an account of work sponsored by anagency of the United States Government. Neither the United StatesGovernment nor any agency thereof, nor any of their employees,makes any warranty, express or implied, or assumes any legalliability or responsibility for the accuracy, completeness, or use-fulness of any nformation, apparatus, product, o r process disclosed,or represents that its use would not infringe privately owned rights.Reference herein to any specific commercial product, process, orservice by trade name, trademark, manufacturer, or otherwise doesnot necessarily constitute or imply its endorsement,recommendation, or favoring by the United States Government orany agency thereof. The views and opinions of authors expressedherein do not necessarily state or reflect those of the United StatesGovernment or any agency thereof.

7/28/2019 1650167

3/75

DISCLAIMERPortions of this document may be illegiblein electronic image products. Images areproduced from the best available originaldocument.

7/28/2019 1650167

4/75

DOE/MC/27403 -- 5242(DE9601 1321)Distribution Category UC-102

250 M W Single Train CFB Cogeneration Facility

Annual ReportOctober 1993 - September 1994

Wo rk Performed Under Co ntract No.: DE-FC21-91 MC27403

ForU.S. Department of EnergyOffice of Fossil EnergyMorgantown Energy Technology CenterP.O. Box 880Morgantown, W est Virginia 26507-0880

BYYork County Energy Partners, L.P.25 South Main StreetSpring Grove, Pennsy lvania 17362

February 1995

7/28/2019 1650167

5/75

TECHNICAL PROGRESS REPORT

I. INTRODUCTION..................................................................................A. Purpose of Rep0rt..............................................................................B.C. Outline of Report ..............................................................................Overview Description of Facility.......................................................

II GENERAL, YCEP DESCRIPTION.......................................................A . General Description...........................................................................B. Technology D escription ....................................................................C. Buildings and Structures....................................................................D. Major Equipm ent List .......................................................................

III. PROJECT SITE .....................................................................................A. Site Location .....................................................................................B. Facility Description...........................................................................C. P.H.Glatfelter Company ..................................................................D. Specific Site Parameters (North Codorus Township) .........................E . Plant Equipment Overview................................................................F. Detailed Equipment Descriptions ......................................................1 Circulating Fluidized Bed B oiler Design ....................................

2. Boiler Pilot Plant Tests...............................................................3. Coal Handling and Storage.........................................................4. Ash Handling and Storage..........................................................5. Chem ical Handling and Storage.................................................6. Limestone H andling and Storage................................................7. Turbine ......................................................................................8. Draft System ..............................................................................H. Pollution Control...............................................................................I. Facility Water Usage .........................................................................J. Facility W astewater...........................................................................K. Air E missions..................................................................................... .

IV PROGRESS SINCE LAST REPORT ...................................................A.B. Baghouse...........................................................................................C. Fuel H andling....................................................................................D. Balance of Plant ................................................................................E. Geotechnical Investigations...............................................................

Foster W heeler Preliminary Design W ork .........................................

1

5556781111

223036373738434 4454648505051515152

W3687WCA -1- 02/14/95

7/28/2019 1650167

6/75

_ _ ~ - _TECH NICAL PROGRESS REPORT(continued)V. TECHNICALSTUDIES COMPLETED SINCE LAST REPORT...... 53

A. Addition of Limestone Rail Unloading.............................................. 53B. W astewater Reuse Study ................................................................... 53C. Main Steam Pipe Material Selection.................................................. 55D. Cooling Water Optimization.............................................................. 55E. Circulating Water Pip e ...................................................................... 55

VI. CLOSURE .............................................................................................. 56LIST OF FIGURESFigure 1 - Process Flow DiagramFigure 2 - Site Location M apFigure 3 - Artists RenderingFigure 4 - Site Plan: North Codorus TownshipFigure 5 - CFB Boiler Plan & ElevationFigure 6 -INTREX ayoutFigure 7 - Pilot Plant Process Flow DiagramFigure 8 - Fuel Handling SchematicFigure 9 -Water Bdan ce

02/14/95.W3687WCA -11-

7/28/2019 1650167

7/75

YORK TECHNICAL PROGRESS REPORTI. INTRODUCTION

A. Purpose of ReportThis Technical Progress Report (Draft) is submitted pursuant to the T ermsand Conditions of Cooperative Agreement No. DE-FC21-90MC27403between the Department of Energy (Morgantown Energy TechnologyCenter) and York C ounty Energy Partners, L.P. a who lly owned projectcompany of Air Products and Chemicals, Inc. covering the period fromJanuary 1994 to the present for the York County Energy Partners CFBCogeneration Project. Th e Technical Progress Report summarizes the workperformed during the most recent year of the Cooperative Agreementincluding technical and scientific results.

B. Overview Description of FacilityThe Department of Energy, under the Clean Coal Technology program,propo ses to provide cos t-shared financial assistance for the construction of autility-scale circulating fluidized bed technology cogeneration facility byYork C ounty Energy Partners, L.P (Y CEP). YCEP, a project company ofAir Products and Chemicals, Inc., would design, construct and operate a250megawatt (gross) coal-fired coge neration facility on a 38-acre parcel inNorth Codorus Tow nship, York County, Pennsylvania. The facility wouldbe located adjacent to the P. H.Glatfelter Company paper mill, the proposedsteam host. Electricity would be delivered to Metropolitan Edison Company.The facility would demon strate new technology designed to greatly increaseenergy efficiency and reduce air pollutant emissions over cu rrent generallyavailable comm ercial technology which utilizes coal fuel. Th e facility wouldinclude a single train circulating fluidized bed boiler, a pollu tion control trainconsisting of limestone injection for reducing emissions of sulfur dioxide bygreater than 92 percent, selective non-catalytic reduction for reducingemissions of nitrogen oxides, and a fabric filter (baghouse) for reducingemissions of particulates.

C. Outline of ReportThe next section of this repo rt (Se ction 11) provides a general d escription ofthe facility. Se ctio nII I describes the site specifics associated with thefacility at the proposed site to North Codorus Township. This section of thereport also provides detailed descriptions of several key pieces of equipment.Th e circulating fluidized bed boiler (CF B), its design, scale-up and testing isgiven particular emphasis. Section IV d escribes progress since the last report

W3687WCA -1- 02/27/95

7/28/2019 1650167

8/75

including preliminary engineering procurement and site related activities.Several key studies performed this past year are described in Sectio n V.II. GENERAL YCEP DESCRIPTION

A.

B.

W3687WCA

General DescriptionThe YC EP facility is a coal-fEed CFB boiler cogeneration facility producing250 MWe (gross) or 227 MWe (net). The power island consists of a FosterW heeler Circulating Fluidized Bed (CFB) boiler and a "utility style" reheatturbine generator. The facility also includes a baghouse, a stack, a coolingtower, c oal unloading and storage facilities, limestone unloading and storagefac ilitie s, c h n i n e M m ~ o nystem, and a gray water treatment facility.The purpose of this project is to help demonstrate the com mercial viability ofusing a utility-scale circulating fluidized bed technology in a cogenerationfacility to generate electric power fo r a local utility and steam f or local hostindus tries. This project is one of a number planne d to be conducted pursuantto the Clean Coal Technologies program to dem onstrate different approachesand applications of clean coal technologies. Succe ssful futu re commercialapplication of circulating fluidized bed technology could result in reductionsin air emissions at costs lower than those of conventional pollution controltechnologies. In addition to the direct economic benefits accruing from thelower cost of producing electric power and the environmental benefits ofdecreased air pollutant emissions, the future commercial application ofcirculating fluidized bed technology would also assist in reducing thedependence of the U nited States upon im ported energy.The proposed facility would also assist in meeting an energy shortfallprojected by the Pennsylvania Public Utility Commission to occur in theregion served by M etropolitan Edison Company. To m eet this need forelectric pow er in the region, new pow er genera tion facilities will be required.In addition, the provision of steam to the steam host enhances the efficiencyof energy use at that facility, The proposed cogeneration facility wouldtherefore assist in serving &e needs of th e comm unity for electrical powerand the needs o local indu for steam power, while m eeting its primaryobjective of dem onstrating a clean coal technology.Technology DescriptionThe facility will use eastern bituminous coal as its primary fu el in a FosterWheeler CFB boiler. The steam produced in the boiler will generate227 MW (net) of electricity in a Westinghouse turbine generator consistingof an opposed flow high pressure - intermediate pressure turbine element anda d ual flow low pressure turbine element coupled to a surface condenser. AProcess Flow Diagram is shown in Figure 1.

-2- 02/14/95

7/28/2019 1650167

9/75

Emissions will be minimized through the use of the CFB boiler technology.Limestone will be injected into the boiler to capture sulfur dioxide (Soy),reducing SO2 emissions by 92%. Combustion air will be staged, combustiontemperatures controlled, and aqueous amm onia or urea w ill be injected intothe cyclones to con trol nitrogen oxide (INOX) emissions. Carbon monoxideand hydrocarbon emissions will be minimzed through the efficientcombustion process which wcurs in a circulating fluidized bed boiler.Particulate em issions will be controIkdwith a baghouse prior to the flue gasentering the stack.The major new technology m a nvolves the CFB boiler which will be thelargest single train unit in the U.S. For large scale steam generator design,mechanical design requirements such as strucfural support, tube thickness,material selection, etc. and many process Considerations such as s t e d w a t e rcircuitry design for natural circulation and steam superheating have beenstandard practice for many years. Th e main areas of scale-up for the subjectunit are the processes related to fluidized bed combustion: furnace design,cyclone design, recycle heat exchanger design, and heat recovery areadesign.In designing a large scale CFB furnace, the primary area of concern is toprovide the conditions for optimum emission control, fuel burn-up, and heattransfer. These cond itions can be achieved by providing good fuel, sorbentand airmixing, as well as the proper configuration of heat transfer surface.In designing a utility scale unit furnace, good fuel mixing fo r uniform fuelburning will be achieved by:

Limiting the furnace depth so that fuel distance of travel from fron t to rearwall is minimized and good penetration and mixing of second ary air canbe achieved.Telescoping the furnace width and adding more fuel, limestone, andsecondary air feedpoints as well as the number of recycled solids returnports which uniformly distribute nx ycle d solids and promote mixing.Adding a full division wall that distributes heat transfer surface foruniform heat removal.

C. Buildings an d StructuresA main pow er island building will be constructed which consists of a numberof adjacent or interconnected buildings, the largest of which will be theboiler building. This building will house the boiler combu stor, cross-over,cyclones, air preheater, fuel day silos, primary air fan, and ash collection

W3687WCA -3- 02/14/95

7/28/2019 1650167

10/75

system. The building will be equipped with a freight style elevator tofacilitate maintenance.T he next building is the feedw ater heater building. This building, which isadjacent to the boiler building contains all facility feedwater heaters. Allheaters are arranged in a stacked fashion to facilitate piping and minimizefoo t print requirements.Th e next building is the tmbine/generatgr building. This building is adjacentto the feedwater heater bu g. This building hom es the turbidgeneratortrain and s~pportystems, swrface condenser, boiler feedwater pumps, andauxiliary pumps and equ&ment, This building will be equipped with amaintenance bridge crane for servicing the major machinery within. Thebuilding has also been designed to allow direct loading and unloading offlatbed delivery truck by means of a drive-in bay on the first floor of theb d d i n g .A control/maintenance/visitor's center building which will house all powerisland and m ain operations overseeing functions, offices, show ers, restrooms,spare parts storage, and maintenance areas. In a ddition, a comp lete visitor'scenter with conference room and reception area will be included in thisbuilding.Other miscellaneous buildings on the site include the coal unloadingbuilding, the ash leading 'building, and water treatment buildings. Allbuildings will be constructed with an architectural siding to accomplish a"comm ercial" look for the facility which will compliment the architecture ofthe existing P. H. Glatfelter Com pany structures.

D. Major Equipment ListA list of major equipment include:

One Foster Wheeler C ireulating Fluidized Bed Boiler (CFB)One Steam Turbine GeneratorOne S ingle Flue StackEight Com partment Baghouse & I.D. FanCoal, Ash and L imestone Handling EquipmentWater Treatment Sys ternThreeBoiler Feed Pum ps (electric mo tor driven)Emergency Boiler Feed Pump (steam-turbine driven)Eight Cell Cooling TowerCondenserPower Transformers and Sw itchyardDistributed Control SystemFire Protection system

W3687WCA -4- 02/14/95

7/28/2019 1650167

11/75

7/28/2019 1650167

12/75

proposed YC EP facility would be designed to op erate continuously (24 hoursper day, 365 days per year), with the exception of outages for m aintenanc epurposes. Facility output would vary between 114 and 227 M W , dependingon Met-Ed's hourly power requirements. When ope rating at less than fullcapacity, coal and limestone use would be decreased. The steam generatedin the boiler would be used to drive a steam turbine to produceelectricity for sale to M et-Ed. A portion of the high pressure steam exitingthe s t eam turbine would be so ld to the P. 3, Glatfelter Com pany fo r use in itspaperdloperations.As part of this operation, the P. H. GlatfeIter Company wo d d be curtailingoperation of one of their existing coal-- boilers. During periods when the

Unit is down for maintenance9Power Boiler #4 wou ld operate toprovide the steam supply needed for the paper milloperation.The primary fuel supply for the proposed cogeneration facility would beUnited States eastern bituminous coal from western Pennsylvania and/orWest Virginia. Run-of-mine (coal as produced at the mine ) would bewashed at the coal mine preparation plant, loaded into rail cars, and deliveredto the YCEP site by rail. The washed coal would have a sulfur content oftwo perc ent or less. Propane would be used as supplemental fuel underlimited circumstances (for example, during facility startup when thissupplemental fuel would be needed to operate the start-up burners in theCFB boiler to warm the CFB boiler prior to firing the coal fuel). Thepropane would be stored on-site in three 30,000-gallon horizontal tankslocate d north of the boiler baghouse.An artist's rendering of the proposed YCEP cogeneration facility is providedin Figure 3 and the site plan is p resented in Figure 4. These draw ings showthat pro ject operations would be com pletely enclosed. Landscaping andberming w ould be incorporated into the facility design to screen ground levelactivities from Route 116. The new rail spur would be designed to ensurethat rail cars delivering coal to the site are accommodated completely off th emain line to eliminate potential impact to rail traffic on the York rail line.

C. P. H. GBatfelter CompanyPHG is B manufacturer of printing, writing and specialty papers. PHGoperates three paper mills located in Spring Grove, Pennsylvania, PisgahForest, North Carolina and Neenah, Wisconsin, respectively. The companyis headquartered in Sp ring Grove which is also the location of its largest milland near the s ite of the proposed YCEP facility.The Spring Grove mill manufactures printing and Writing papers. The millemploys 1200, 800 of whom are represented by the United PaperworkersInternational Union. The facility is electrically self-sufficient, capable of

W3687WCA -6- 02/14/95

7/28/2019 1650167

13/75

producing over 1.1 million pounds of steam per hour from three coal-firedboilers and one chemical recovery boiler (which recently replaced two olderboilers). One of PHG's coal-fired boilers is a CFB which began operating in1989. Steam provided by the YCEP facility will obviate the need tocontinuously operate an existing pulverized coal boiler (called the No. 4boiler) which has been in use since the 1950's. As a result, overall emissionsof sulfur dioxide will be cu t in half, and net emissions of nitrogen oxides andparticulate matter will be reduced by m ore than 20%.

D. Specific Site Parameters (North Cudorus Township)For the site, the P.H. Glatfelter key design basis criteria include:

Site Size 38 acresOne F oster Wheeler CirculatingFluidized Bed Boiler: 2,100,000 lb/hrOne Turbine-Generator:Start-up Fuel:Auxiliary Boiler Fuel:Coal Delivery:Disposal of Bed and Fly Ash:Voltage:Pow er Purchaser:Export Steam Host:steam Flow:575psig/68OoF

Cooling Water Mak e-up Source:

227 MW NetPropaneNoneRail via SpurTrucks to Offsite Disposal115kVMetropolitan Edison CompanyP. H. Glatfelter Com pany

400,000 lb h r Maximum300,000 lb/hr Nom inalP. H. Glatfelter CompanyWastew ater Treatment Plant

W368lWCA

Condensate Return:

-7-

100%

02/21/95

7/28/2019 1650167

14/75

E. Plant Equipment OverviewCoalwill be delivered to the site via unit trains roughly every 4 to 5 days atfull facility capacity, The coal will be unloaded in an enclosed building andconveyed to storage silos for later use. Limestone wil l be delivered via truckand loaded pneumatically into storage silos for later use.The boiler wil l use approximately 98-5 tons per hour of coal and 18.2 tonsper how of limestone to produce 2.1 mm h / h r of 2,550 psig steam atl,oo5F. The steam is ""utility style'' reheat condensing turbinewhich has a combined and intezmediate pressure section along with alow pressure section to produce apprnximatdy250 grossMw of electricity.Of that electricity, 227Mw dl be sold ts Met-Ed under a power salesagreement.Combustion gas produced by the boiler is sent through a baghouse w here thegas is filtered and directed to the stack.The facility's gray water treatment system consists of a series of clarifiersand mixing tanks which take gray water from the PHG paper makingoperation and produce water of adequate quality fo r all uses in the facilitywith the excep tion of potable needs.Th e demineralization system includes three trains each capable of producing500gprn of demin water (total facility need is 1000gpm). Each trainconsists of anion, cation, and mixed beds along with all regenerationequipment, regeneration waste neutralization equipment, chemical storageand injection equipment, and a 360,000 gallon storage tank.The cooling tower wil l provide more than 100,000 gpm of water to thesurface condenser along w ith ad ditional minor flow s to other facility uses.The facility auxiliary power needs of approximately 21NW will be met bythe turbine/generator when the facility is ating. When the facility isdown, M et-Ed can back feed the facility from themain step -up transformer.Control, monitoring, ~~~~a~~~ and load following, billing, guaranteeadministration and emission monitoring of the facility will beaccompfished using a state-of-the-art distributed con trol system ("DCS 'I).Fire protection of the facility wi l l be provided by an underground pipingsystem which will service hydrant stations and sprinkler systems water willbe provided from a fire water pump package taking sup ply from the Codoruscreek adjacent to the facility. The pump package w ill be located so as to takewater supply from the same intake structure as the existing PH G fire waterand back-up w ater supply pumps.

W3687FcTCA -8- 02/14/95

7/28/2019 1650167

15/75

Several off-site features are associated with the proposed YCEP project.These are:

an electrical interconnection with the existing Met-Ed system ;a steam line conn ect hg the facility with the P. H. Glatfelter Com pany;a condensate renun line from the P. 3. Glatfelter Company to the facility;connections to and from the P.H. Glatfelter Company's wa ter systems forwater supplies and wastewakr disposal; anda connection to Spring Grove Water Company.

Each i s briefly described below.Electric InterconnectionThe Y CEP facility will interconnect with Met-Ed's system in two areas. Thefirst electric interconnection proposed would be a single circuit 115 kV linewhich would interconnect with an existing Met-Ed 115kV line.The second area would be a 115kV double circuit line ex tending north fromthe YCE P site across Codorus Creek and would tie into an existing Met-Ed115kV ine on the P. H. Glatfelter plant site.During construction, electricity would be provided by Met-Ed through aconnection with Met-Ed's existing system. Telephone cab les, providingphone service to the on-site construction office, would be strung from linesextending along Route 116.Steam LineKondensate Return LineA 18-inch steam line would be required to transport process steam from theproposed cogeneration facility to the P. H. Glatfelter Company. Theinsulated steam line would be supported aboveground on piers, with theexception of locations where the line traverses transportation features. Thesteam line would extend from the proposed YCEP facility in an easterlydirection, crossing the breakwater between Kessler Pond and the mill pondbefore crossing the Codorus Creek on an existing P. H. Glatfelter Companypipe bridge. The condensate return line (eight inch) from the P. H. GlatfelterCom pany w ould closely parallel the steam line route.

W3687WCA -9- 02/27/95

7/28/2019 1650167

16/75

Water Supply LineA small portion of the total facility water (primary potable water) need isproposed to be supplied from the Spring Grove Water Company. Theinterconnection would be via an eight-inch supply line which wouldinterconnect with an existing Spring Grove Water Company line along aprivate mad, o m d by P. H.Glaitfelter Company, leading to theP. H. GMfelte9 Company primary wastewater treatment facility. The linewould follow the private road, cross under S.R. 116, cross theP. H. Glatfelter C Q ~ P Z L I I Yrack parking lot, then extend over the breakwaterbetween Kessler Pond an8 he mill pond to the facility. Process and rawwater back-up supplied by P, H, G l a e e b r would be met by a six-inch supplyLine extend ing across the b reakw ater? then n orth across the existing pipebridge. A temporary interco nnection to P. H. Glatfelter Com pany along thisroute would also be used to supply water needs during the constructionperiod.The supply of the P. H. Glatfelter Company treated wastewater to thecogeneration facility for plant cooling would be handled by a 14-inchpipeline constructed from the treatment plant effluent area to the east side ofthe YCEP facility. This preferred pipeline route would run do ng corridorswh ich contain existing underground pipelines. This route would cross thebreakwater between Kessler Pond and the mill pond, extend through theP. H. Glatfelter parking lot and under Route 116, and continue along aprivate road to the P. H. Glatfelter Company wastewater treatment plant. Aten-inch firewater line would also be run from the P. H. Glatfelter Companyintake structure, across the breakwater to the proposed Y CEP facility.Wastewater Discharge LinesThe proposed YCEP facility wastewater (cooling tower blowdown andtreated sanitary wastewater) would be discharged to the P. H. Glatfelterwas tewater treatmen t system equalization basin. The preferred route for theconnection to the equa lization basin would be a corridor heading east acrossthe breakwater, through the P. 3. Glatfelter parking lot, under Route 116,and along a private road t o the equ on basin. This route would be thesame as the route for cooling water make-up.In addition, a h e ould be mn from the P. H. Glatfelter equalization basinto the secondary treatment n i t to handle additional flow. This line wouIdparallel &e route for the cosf;mg water m ake-up pipeline.

W3687WCA -10- 02/27/95

7/28/2019 1650167

17/75

F. Detailed Equipment DescriptionsTh e following sections provide a detailed description of each of the majorequipment groups.1. CirculatingFluidized Bed Boiler Design

Fuel is fed to the base of the combustor don g both the front and backwalls and sorbent is fed to the base of the combustor along the frontprimary and secondary air fans. Before entering the co mbustor, theses t r m s are preheated via heat exchange with the f lue gases in the airheaters. The heart of the process is a circulating fluidized bedcombustor in which the fuel is combusted while simultaneouslycapturing S%. Selective non-catalytic reduction of NOx emissions isaccom plished through injection of aqueous amm onia or urea at the inletto the cyclones. Solid particles entrained by the upflow ing gas in thecombustor exit the top of the combustor into cyclones which efficientlyseparate the flue gas from the entrained particles. The flue gasdischarged from the cyclone is directed to the dow nstream convectivesection of the boiler and the ca ptured solids are recycled to the base ofthe ACFB by means of standpipes, J-valves, and an IPJTREXWfluidized bed Integrated Recycle Heat Exchanger. The J-valves providea seal between the positive pressure in the lower furnace where therecycle solids are fed and the near ambient pressure in the cyclones.Refer to Figure 5 for an elevation of the CFB boiler.

wall. mq and secondary ;air s to the combustor are provided by

Coarse ash material (bed ash) accumulating in the ACFB is removedfrom the bed using a specially designed directional grid and a fluid izedbed stripper cooler. The bed ash is cooled by the fluidizin g air flow tothe stripper cooler. This heated air stream flows to the combustor alongwith the fines that are stripped out. The cooled bed ash will beconveyed to a bed ash silo. Fly ash collec ted in the air heaters,economizer, and baghouse hoppers wil l be pneumatically conveyed tothe fly ash storage silo. Depending on the beneficial use for theby-product ash, the bed and fly ash streams may require additionalprocessing to condition the ash.Boiler feedwater is preheated in the economizer located in theconve ction heat recovery area, The preheated feedwater is then routedto the steam drum. From the steam drum, the pressurized water flowsby natural circulation through the waterwall sections of the ACFBcombustor and the I N T R E G M heat exchanger. Steam generated in thewaterwall boiling circuits is routed to th e cyclone enclosure walls, theconve ction heat recovery area enclosure walls, the prim ary superheater,and then on to the intermediate and finishing steam coils located in the

W3687WCA -11- 02/14/95

7/28/2019 1650167

18/75

W3687WCA

I N T R E P heat exchanger. This superheated steam flow is expandedthrough a high pressure steam turbine. A portion of the steam exitingthe high pressure m b i n e flows through a reheater located in theconvective heat recovery area. The reheated steam is expand ed throughan ntermediate pressw e steam turbine to extract add itional power.A description of the major components which comprise the coal-firedACFB cogeneration plant is given below.

Coal and sorbent, sa& as limestone, are fed h t o the lower, refractory-lined portion of the atmospheric circulating fluidized bed where thesefeedstock materials are mixed with the bed material and initialcombustion OCCUTS. To support combustion of the coal, asubstoichiometric amount of air is fed to the base of the unit andadditional air is injected at two different elevations above the primaryair feed location. The total air flow is approximately 20% in excess ofstoichiom etric requirements. Primary air enters through a speciallydesigned air distribution grid. This process of staging th e air flow to thecombustor minim izes the formation of NOx within the unit. In addition,the relatively low operating temperature of the ACFB combustor of1550-1650Falso minimizes NOx lormation. The sorbent is fed to thebed to capture SO2 formed by the combustion of sulfur-con taining fuel.Calcium carbonate is calcined to calcium oxide in-situ whichsubsequently reacts with SO2 nd 02 to stabilize the sulfur in the formof calcium sulfate. Maintaining the bed temp erature at approxim ately1600F is also necessary for effective sulfur capture and to minimizesorbent consumption,Th e upflowing combustion gases entrain the fine ash, char, and sorbentparticles producing a net flow of solids up through the combustor. Th ecombu stor temperature is maintained by efficient transfer of heat fromthe gas-solid suspension to the waterwall tubes. Solids entrained fromthe bed, including unburned char and urn ac te d sorbent particles, arecaptured by hot cyclones and =turned to the ACEB combustor, Thispromotes im proved combustion and sorbent otilization efficiency. Therecycled solids are d s o cooled upon passing through the steam-cooledcyclones and the INffREm heat exchanger. A side elevation drawingof the I N T R E P unit is given in Figure 6. The cooled recycle solidsstream also helps to moderate the temperatures within the combustor.Coarse ash particles are removed from the bottom of the com bustor asbed ash. Additional heat is recovered from flue gas and fine ashparticles escaping the cyclones within the convective section of theboiler. Th e fly ash is captured in a baghouse before the cooled flue gasis exh austed through a stack.

.12- 02/14/95

7/28/2019 1650167

19/75

W3687WCA

SDent Bed Material CoolinP SvstemCoarse coal ash, spent sorbent, and calcium sulfate must be removedfrom the bottom of the ACFB boiler to control solids inventory in thelower region of the b d ~ . irectional air distributor nozzles are usedon &e furnm flooreach hate sidewall. Wow gattern along the base of thecombustor eauses th e to drain to the stripper cooler andalso m-s the of the large fuel particles in thecombustor to reduce mbmed carbon levels in the bed ash. Four (4)50% capacity fluidized bed str ippdcoolms are designed to selectivelyremove oversized bed material and return fine material back into th efurnaces to increase the solids residence time. The stripperlcooler is arefractory lined box with three fluidized compartments; one stripperzone and two cooling zones. A fraction of combustion air is used tostrip and cool the spend bed material to an acceptable temperature levelfor disposal. Sensib le heat in the spent bed material is recovered byinjecting the stripping and cooling air back to the fu rnac e as part of thesecondary air for com bustion.

e material to the drain openings on

y J yr i rThe circulating fluid bed design is comprised of fou r distinct sections:the furnace, the hot cyclones, the INT RE XW heat exchanger, and theheat recovery area (HRA). All four sections are top supported and arecom prised of water or steam cooled enclosures. Use of integrallywelded steam generating walls as the enclosure is in accordance withmodern design practice and provides both the required cooling and thestructural support. The steam circuitry is designed for naturalcirculation and includes a single drum located above the furnace andbetween the furnace and cyclones. The boiler is designed to turn downto 40 percent of MCR capacity without firing auxiliary fuel and to havea steam temperature control range betweean 75%and 100%MCR load.Boiler fedw ate r enters unit at &e inlet to the bare tube economizerin &e convection h a t ~%coveryrea. Water flows through theof horizontal coils countercurrent to the flue gas, exiting at theoutlet header. Feedwater is then routed to the steam drum. Steamgenerated in the boiling circuits is separated by the steam druminternals. The s t em drum intema ls are designed to efficiently separateth e s teadwate r mixture, and to insure that the steam leaving the drum ismoisture free and of high purity. In addition , the drum internalsdistribute the flow of incoming water and steam throughout the drum tomaintain even drum metal temperatures. The internals consist of

-13- 02/14/95

7/28/2019 1650167

20/75

horizon tal centrifugal separators located along the side of the drum andunit Chevron drier assemblies arranged along the top of the drum.Steam leaving the drum through the Chevron dryers is routed to thecyclone circular enclosure walls, HRA enclosure walls, the HRAprimary superheater, and then on to the intermediate and finishingsuperheater coils located in &e INTREXm heat exchanger. Two spraytype attemperators are provided, located between the primary and theintermediate superheaters and b e t w e n the intermediate and finishingsuperheaters to pro C O I I ~ ~f the final steam temperature. Thistype of attempration will afford excellent control flexibility an d willnot adversely af fect stem purity.Reheat steam enters the unit at &e reheater inlet header located in theparallel pass HRA. Steam flows through the reheater banks ofhorizontal coils countercurrent to the flue gas flow, exiting at the outletheader. Reheat temperature control is achieved through simple flue gasflow proportioning thereby eliminating the need for spray-typeattemperators.Thermal DeNOx Svstem

W368TWCA

Low level emissions of NOx generated by the oxidation of fuel nitrogenwithin the ACFB combustor will be further reduced by decomposingNOx into N2, 02, and H20 using non-catalytic reduction withammonia. Aqueous ammonia or urea will be injected directly into theflue gas in the (4) ucts connecting the cyclones to the combustor. Atthis location, the temperature of the flue gas at 100% MCR will beapproximately 1630F. At this temperature the NOx redu ction reactionsproceed at a sufficient rate to achieve a NOx reduction level of 50%.Since staged combustion and low combustion temperatures alreadycontribute to significantly lower NOx emissions than achieved withconventiona l pulverized coal boilers, extremely low NOx emissions willbe achieved by combining the two technologies.Technical Challengesin Seale Up of ACFB DesignEvolution of ACFB Technolow in U.S.The size of the YCEP ACFB com busto r represents a sign ificant increasein scale over existing ACFB combustors. Curren tly, the largest singleACFB boilers are the 1 50 M W e Texas-New Mexico ACFB and the165MWe Pt. Aconi Nova Scotia, ACFB. However, when the YCEPproject is started up in late 1997, it will become the largest ACFBcombustor, capable of generating 227 MWe of net electrical power and

-14- 02/27/95

7/28/2019 1650167

21/75

W3687WCA

electrical pow er and up to 400,000 lb/hr of export steam. This scale willbe most representative for potential utility-scale ACFB applications.ant challenge in &e design of the single combustor ACFB forthe YCEP project was to anticipate the influence that the scale of thecombustor wodd have on its design and performance. Th e followingimportant considerations in designing am certainty of successfuloperation. The ssed include:

Flexibility of T herm al DeGgnSolids M ix in fl ed DistributionCyclone Se parator Design/Configur&onDesign of ACFB Waterwa 1 SurfaceIn scaling up the design of A CFB combustors, proper thermal design isimportant to control the temperature within the combustor. A properlydesigned ACFB combustor will operate at uniform 1,600-1,65OoFtemperatures, which w ill perm it combustion to take place below the ashfusion temperature while providing optimal SO2 capture with calcium-based sorbents and reduced NOx form ation. This is achieved bybalancing the heat released by the combustion process with the heatabsorbed within the boiler. Heat absorption is achieved by w ithdrawingheat from the gas-solid suspension within the boiler, the cyclones, andINTREm heat exchanger. Adequate temp erature control and solidsdistribution/rnixing are essential to attaining high combustionefficiencies and minim al gaseous emission rates.Since the fluidizing velocity of ACFB's is held constant, the cross-sectional area of the com bustor increases propo rtionately with the firingrate. How ever, as the bed cross section increases, the ratio of bedvolume per unit of wall heat transfer surface area increases. As thecross-sectional area increases for a unit of a given height, the amount ofheat that can be removed through the waterwalls becomes a smallerfraction of the firing rate.One method of obtainhg the totaI required heat transfer surface is toincrease the com bustor r; how ever, the heat transfer surface that is

d height is least effective at removing heat. Thisof hait transfer varies with the solid suspensiondensity and &e solid suspension density in the YCEP combustordecseases rapidly with height until reaching a constant value in theupper furnace. This results in a more predictable heat absorption in theupper furnace. Furtherm ore, a lowe r density in the uppe r furnace results

-15- 02/14/95

7/28/2019 1650167

22/75

up to 400,00Olb/hr of export steam. This scale will be mostrepresentative for potential utility-scale ACFB applications.A significant challenge in the design of the single combustor ACFB forthe YCEP project was to anticipate the influence that the scale of thecombustor would have on its design and performance. The followingsections will discuss several important considerations in designing a227W e CFB combustor having maximum certainty of successfuloperation. The majo r design features to be discussed include:

Desicn of ACFB W aterwall SurfaceIn scaling up the design of ACFB combustors, proper thermal design isimportant to control the temperature within the combustor. A properlydesigned ACFB combustor will operate at uniform 1,600-1,65OoFtemperatures, which will permit combustion to take place below the ashfusion temperature while providing optimal SO2 capture with calcium-based sorbents and reduced NUX formation. This is achieved bybalancing the heat released by the combustion process with the heatabsorbed within the boiler. Heat absorption is achieved by withdrawingheat from the gas-solid suspension within the boiler, the cyclones, andINTREXTMheat exchanger. Adequate temperature control and solidsdistributiordmixing are essential to attaining high combustionefficiencies and minim al gaseous emission rates.Since the fluidizing velocity of ACFB's is held constant, the cross-sectional area of the com bustor increases proportionately with the firingrate. However, as the bed cross section increases, the ratio of bedvolume per unit of wall heat transfer surface area increases. As thecross-sectional area increases for a unit of a given height, the amount ofheat that can be removed through the waterwalls becomes a smallerfraction of the f d g atese,One method of obtaining the total required heat transfer surface is toi n c r e ~he combu stor height; however, the heat transfer su rface that isintroduced with added height is least effective at removing heat. Thisoccurs because the rate of heat transfer varies with the solid suspensiondensity and the solid suspension density in the YCEP combustordecreases rapidly with height until reaching a constant value in theupper furnace. Th is results in a more predictable heat absorption in theuppe r furnace. Furthermore, a lower density in the upper furnac e results

W3687WCA -15- 02/27/95

7/28/2019 1650167

23/75

W3687WCA

in less heat release, which is cons istent with the lo wer he at absorption inthe upper furnace.In the YCEP ACFB design, the required amount of heat is removedthrough addition of a water-cooled, fu ll division wall extending alongthe entire height of the combustor. This development introducesadditional heat transfer surface throughout the entire furnace height.The division wall reduces the mtio of bed volume to the heat transfersurface area to a vdue that is typical of existing, smaller ACFBcombustom,Other advantages of&e full division wall include:

More miform temperature distribution in the ACFB. In comparisonwith a single chamber design, the division wall will help to producemore uniform temperatures across the ACFB due to the more evendistribution of heat transfer surface throughout the combustor crosssection.Low er unit height. A full division wall will allow combustor heightto be constrained to that required for the cyclones rather than thatrequired to achieve the necessary waterwall smfac e. Capital costsavings resu lt by e liminating the nee d for additional structural steel,platforms and building enclosures. Reduced combu stor height willalso typically result in a low er stack height.

Special design features included in the proposed furnace division wallinclude:Pressure Equalization OpeningsFrom the furnace floor to a height of about 12ft., the fins betweenadjacen t division wall tubes are removed. This allows the tubes tobe bumped sideways, in-plane, to fom multiple openings.Additional openings are also provided in the upper furnace over it12ft. span beneath the cyclone inlet. The openings in the upperfurnace are located beneath the cyclone inlets to minimize lateralcross-flow of solids t.hough the openings. The division wallopenings function to equalize the pressure on both sides of thedivision wall.The p ressure equalization openings eliminate differential forces onthe division wall, which sim plifies the mechanical design. Also, auniform air flow can be maintained across the width of the unit.Excess oxygen in the flue gas can be monitored at a commonlocation at the heat recovery area exit and secondary air flow can be

-16- 02/14/95

7/28/2019 1650167

24/75

modulated to maintain the desired excess air level. Independentmonitoring and modulating controls for each side of the divisionwall are not requited.WearResistant DesignAt the pressure equalization openings the division wall tubing isprotected with the same high conductivity, erosion resistantrefractory used on the lower furnace enclosure walls, roof, cyclonecyclones. The phosphate-bonded, high-aluminarefractory which contains stainless steel reinforcing fibers ismounted on a high density stud pattern to a thickness of 1/2inch.ABI the tubes are kept in plan so as not to protrude into the gas/solidsflow stream for direct impingem ent. In this man ner, the divisionw& will b e no different from the water cooled enclosure wallswhich also have openings for solids cooler drains and fuel,limestone, and secondary air feeds.Diflerential Thermal Grow thThe division wall is welded where it penetrates the air distributorand is held in tension by springs fixed at the top of the unit. A gapis provided between the division wall and the front and rear walls ofthe furnace. Since the divisionwall s heated on both sides while theenclosure walls are heated only on one side, the average divisionwall tube temperature will be slightly hotter than that of theenclosure walls. The support arrangement with no mechanicalattachment to the enclosure walls allows both the division wall andthe enclosure walls to independently grow downward at theirrespective rates. Foster W heeler has designed numerous steam-cooled full division walls on pu lverized coal fxe d steam generators.Steam cooled division walls have more stringent designrequirements fo r differential thermal growth than do water-cooleddivision walls.

Solidmixingplays an mportant role in determining the performance ofACFB Combustors. As the combustor scale increases, changes inseveral design parameters can affect how well the fuel and sorbent aredistributed in the combustor. Data taken from other comm ercial ACFBplants will be presented to show that poor solid mixing can result ininefficient plant operation and higher plant operating costs.The factors which are thought to influenc e the degree of solid mixing inthe lower region of ACFB's are placed in three categories: (a) mixing

W3687WCA -17- 02/14/95

7/28/2019 1650167

25/75

due to external so lid recirculation, (b) mixing due to internal solidrecirculation, (c) mixing knita tion s caused by solids feederconfiguration and boiler dimensions.Impact ofPoor Solid DistributionNonuniform fuel distribution results in increased consumption ofsorbent to achieve the sam e SO2 emission level and m ay also increasethe NOx generation r a k With increased NOx generation, NH3consumption increases to achieve the same level of NO x emissions andth e NH3 slip (flow of unreacted NH3) dso increases. When burningcoals containing chlorine, gxeaaer NH3 ssp increases the potential forNH4Cl formation. Poor fuel distribution will also lead to a reduction incombustion efficiency through increased hydrocarbon and COemissions, and increased calcination heat losses. Nonun iform fueldistribution may lead to oxygen deficient reducing zones that cause bedagglomeration and slagging problems, and may produ ce local hot spotswithin the combustor.Factors Afectin g Sorbent UtilizationThe factors which are thought to influence sorbent utilization include:sorbent and fuel properties, solid mixing, combustor temperature, fueland sorbent distribution, and cyclone grade efficiency. Importantsorbent properties include the reactivity, friability, and feed sizedistribution. These properties will help determine how long the sorbentstays in the ACEB, how it is distributed between the low er and upperfurnace, the extent to which the particle breaks apart to expose freshCaO, and the reaction rate. Impo rtant fuel properties include: volatilecontent, reactivity, sulfur content and forms (organic, pyritic, sulfatic),and eed size distribution. The firing rate per fuel feeder will determinethe local concentration of fuel at the feeder outlet. Increasing the firingrate per feeder will (for more volatile and reactive fueIs) increase thereaction rate within this region, which will result in zones of low 02 andhigh SO2 gaseous concentrations and elevated local temperatures.Combustor temperature plays an important role due to the strongdependence of the sulfur capture reactions and combustion reactions ontemperature. Sorbe nt distribution is also important to ensure a uniformconcentration of um a c te d C aO in the ACFB at the location where theSO2 is released, Th e extent of solid mixing in the ACFB will helpdetermine how well the fuel and sorbent are distributed. Finally, acyclone with high capture efficiency for fines will retain the fineunreacted sorbent particles in the ACFB longer to react morecompletely. It should be noted that the YCEP ACFB boiler has arelatively short mixing zone, a distinct lower furnace bed that uses

W3687WCA -18- 02/14/95

7/28/2019 1650167

26/75

relatively coarse fuel and sorbent, as well as air swept fuel distributors,which promo te more effective mixing in the furnace.&lone Separator D- and C o i fwrationhother design issue important to the successful scale up of ACFBcombustors is&e design of the cyclo ne gas-solid separation system. Asthe size of the G increases, the mass.flow of gas and solidsustor to the cyclones increases p roportionallyOne method ofperforming this ~ p m t i o nith the inmased flow of particle-laden gasis to increase the size of the cyclone. Un fom nate ly, as the cyclone size(diameter) increases the centrifugal force field is reduced (at the samegas inlet velocity) and the particle collection efficiency deteriorates. Inth e absence of high solids collection efficiency, smaller sorben t,carbon, and ash particles escape through the cyclone rather than beingrecycled to the combustor with the cyclone underflow. This wouldresult in inefficient fuel and sorbent utilization and a reduction ininventory of particles capable of circulating and transferring heat,Another drawback of increased cyclone size is that the increased cycloneheight may dictate increased combustor height for the solidsrecirculation system to function properly.To enable high gas-solid separation efficiency with the YCEP ACFBboiler des ign the size of the cyclones was held similar to that utilized insmaller units. However, to accommodate the increased gas flow rate thenumber of cyclones was increased.

d c k size, combustor height, etc.).

The cyclone separator designs features steam cooling and is an integralpart of the steam superheat circuit. Steam cooling of the cyclones offersthe follow ing advantages:Faster unit start-upReduced heat lossesR educed r e q e m e n t s for high-temperature refractory ductwork andexpansion joints

"he follow ing section describes several innovative features of the ACFBsystem design:

The INTREXm heat exchanger is simp ly an unfired fluid ized bed heatexchanger with a non-mechanical means fo r diverting solids. It will

-19- 02/14/953687WCA

7/28/2019 1650167

27/75

take advantage of the high heat transfer coefficients for tubes immersedin bubbling fluidized beds and will also operate advantageously withfine (ZOO micron) particles. Due to the fm e recycle solids and th e lowfluidizing velocities (0.5 to 1.5 Ws) , ube erosion will not be a concern.The TNTREfgTM heat exchanger allows fo r part of th e heat released inthe combustor to be removed o combustor. This method ofheat m n o v d w3H1 eliminate the for excessively tall com bustors orthe need to innstdlh a m anel trude into the erosive flow in.the ~ Q ~ b u ~ ~ ~re subject m excessivewear.The heat exchanger will be enclosed by the same water-cooled membrane constraction used in the furnace. Th e integratedconfiguration wiIl allow it to grow down ward with the rest of the boilersteam/water pressure parts, minimizing differential thermal movement.Placement of serpentine superheater coils within the recirculated solidsflow path enables the entire reheater to be located in a conventionalparallel pass heat recovery area. Final main steam temperature will becontrolled by spray water attemperation, while reheat steam temperaturewill be con trolled by gas flow proportioning in the heat recovery area.FWEC as ex tensive experience in the design of atm ospheric bubblingfluidized bed @FB) heat exchangers from th e 46 BFB steam generatorsthat it has designed and put into operation. Scale up of the IN'IXEXmBFB s not an issue since the main cell in the 130-MWNorthern StatesPower Black Dog unit is about four times greater in plan area than thelargest INTREX cell in the YCEP ACFB. The INTREXm heatexchanger will be divide d into four cells.DOE Clean Coal DemonstrationTestsThis demonstration program is designed to provide the followingimportant information:e Demonstrate unit start up an d shut down capabilities and providedata and experience on ACFB boiler operation during thesetransients.

Demonstrate ACFB boiler dispatching capabilities and constraints.Demonstrate ACE3 boiler operation at full-load conditions forextended periods and continuous operation at part-load con ditions.Provide qu antitative results from a systematic study on the effects ofimportant operating parameters and fuel characteristics on boilerperformance which will aid in the optimum economic design andoperation of futu re units.

W3687WCA -20- 02/14/95

7/28/2019 1650167

28/75

Identify constraints governing fuel selection based on test resultsfrom fou r different fuels.Provide guidelines for inspection and maintenance along withinform ation on maintenance costs.

Included in the test program are specifk operating tests to evaluate theeffects ofthe fsUowhg ope mt hg parameters on ACFB performance:Fuel.size and qualitySorbent size and quality

0 Fuel and sorbent rates0 Combus or temperatureExcess airPrimaqdsecondary air ratioSpecific boiler performance parameters to be quan tified include:

Boiler thermal efficiencyS te d le c t r i c a l Generation Capac ityAbility to control steam temperature and pressureAsh production and qualityBed ash/fly ash splitUnburned carbon losses in bed and fly ashStack emissions: NOx, S02,CO, VOC and particulatePower consum ption of auxiliary equipmentPercent SO2 capture and C d S ratioControl of bed inventoryCom busto r temperature profile

Tests are proposed for four different coals: the design coal (basis forcombustor design) and three test coals having different properties fromthe design coal. The purpose of performing tests with coals havingproperties which differ from the design coal is to determ ine what rangeof coal properties can be utilized and the impact of fuel characteristicson the performance and o p t i n g economics of the ACFB. Differentsorbent m aterials would likely be used during the tests.In addition to performing tests at 100% maximum continuous rating(MCR), tests would be performed to demonstrate operation of the boilerand other ACFB system components during start-up, shutdown, anddispatch of the facility. To dem onstrate the capability of the system. a30-day test with the boiler operating at a minimum of 96% MCR isproposed.

-21- 02/27/95

7/28/2019 1650167

29/75

2. Boiler Pilot PlantTestsa. Introduction and Summary

A p3ot plant test bum was conducted by Foster WheelerDevelopment C orporation at their Livingston, New Jersey facility.The objective of the test burn was to evaluate certain coals andlimestones for possible use in the project. The test burn took onmore h p m m a&r a series of bench scale and pilot plants c m h g ests showed that axtab b e s t o n e s had potential attrition .problems. Accordingly, the test protocol was set up to first evaluatethe atb5tion pr ob lm s. Accodirygly, the test protocol was set up tofirst evaluate the attrition potential of the limestone and thengenerate performance and emission data.

b. Pilot Plant Test FacilityThe circulating fluidized bed combustion pilot plant and laboratoiyfacilities located at Foster Wheeler Development Corporation inLivingston, New Jersey, were utilized for the test program. Thesefacilities are described below:CirculatinP Fluidized Bed Pilot PlankThe new test unit, which has a capacity of approxim ately 2,000 lb/hof superheated steam, is capable of operation in either the bubblingor circulating bed mode. Th e unit is dedicated to the advancementof the technology and incorporates the latest design featuresincluding a welded waterwall furnace enclosure, a castablerefractory-lined cyclone, and provisions for heat transfer surfaceadjustment in both the furnace and heat recovery area. A schematicof the C FB pilot unit is shown in Figure7.The fluidized test module is constructed of monowall andgh combustion chamber, monowall-monowall-one separator, and downflow heat recoveryarea.. The 14-in*x 26-in. combustion chamber has a heat releasecapacity of 2 to 4 miUion Btulh depending upon configuration. Heattransfer to the combustion cham ber walls is limited by a 3-in. layerof meetium-weight catable refractory.

W3687WCA

Fluidizing air enters the combustor through a distribution gridmounted at the centerline of the lower waterwall headers.

-22- 02/14/95

7/28/2019 1650167

30/75

W3687WCA

Directional nozzles introduce the fluidized air. Thermoco uple wellsmounted b o u g h the distribution plate permit the monitoring of bedtempera w e s .Air is supplied to the ~ ~ ~ b ~ ~late plenum, start-up gas burners,fuel feel lime, and overfiie air ports by a positive displacementcompressor rated at 8, 0&?hnh and 18 psig. All air flows aremetered by orific\e plates fitted with electronic flow transmitters.The freeboard space of &e test m d d e is fitted with adjustablelevels of overfire t!ir ports. Cas sampling, and thennocouple portsare provided on 1-ft vertical centers throughout the bed andfreeboard zones.The combustion gas-solids mixture exits the com bustor and passesthrough the integral hot cyclone separator which has a corner voluteinlet. The w ater wall enclosed separator is constructed of erosionres ista dc ast ab le refractory lining. The hot solids are separatedfrom the gas and fall by gravity into a 6-in. tandpipe which runsadjacent to the combustor along its outer wall. The solids arerecycled back to the combustor by use of an aerated J-valve. Sampleconnections, pressure, and temperature ports are provided on thestandp ipe and J-valve.The hot gas stream exits the cyclone and enters the heat recoveiyarea where it is cooled. The cooled gas stream leaves the heatrecovery area and passes through one of two parallel baghouses toremove particulates and ash.A variable-speed I.D. fan is used to pull the gas through the systemand discharg e the gas from the pilot pant through a stack .Sample ports for both batch sampling of solids and gases andcontinuous monitoring and provided at several levels in the testmodule. The control gas sampling pot (ase d for both process controland acquisition of the continuous average gas analysis) is located inthe heat recovery outlet flue where the gas temperature isapproximately 450F. A time gas analysis system providescontinuous analyses for carbon monoxide, carbon dioxide,sulfur dioxide, r&mgen oxides, md otal hydrocarbons.

c. Feedstock Chartactena'zationRepresentative samples of c o d and limestone sorbent were analyzedusing standard physical, chemical and thermal techniques. Results

-23- 02/14/95

7/28/2019 1650167

31/75

of these analyses provided the basis for stoichiometry calculationsand th e selection of pilot plant operating parameters.

Proximate9d h t e ,being value, and ash fusion results for the testin the ~ ~ ~ pable. One c o d was a highwestern Pennsylvania which has beencleaned to lower the ash and d f k r contents (5.9percent and1.4percent, respectively), The ash fusion temperatures weremoderately low in both redncing a d xidizing atmospheres. Theash was relatively high in iron f13.Qpercent Fe2O3), which canform eutectics at temperatures above those encountered duringnormal CFB operation. The coal contained only a minor amount offine material, with only 3 percent less than 200 mesh.

Thermog ravirnetric analysis (TGA) was also performed on the coalutilizing a DuPont TA analyzer. The coal was first devolatilizedunder a nitrogen atmosphere at a heating rate of 36"F/min to a finaltemperature of 1,832"F. The reactivity of the resultant char WESthen evaluated in the TG A by burning it in air at a heating rate of18"F/min. Compared to th e other coal chars, the char appeared tohave a relatively low reactivity and a high burnout temperature(1,380"F). Other tested coals had a relatively low char burnouttemperature (1,200"F) in the TGA and CFB pilot plant carboncombustion efficiency as high as 96percent. Based upon this TGAdata, complete carbon burnout for the coal may be difficult to obtainin the pilot plant, especially due the relatively short gas residencetime (2 seconds).LimestoneCharacterization of the limestone was achieved through elemental,size and therm al analyses. W hile & e techniques fo r elemental andsize analyses are well known, the TGA sorption test is equipmentdepen dent and, therefore, has been satmrassUizedbelow.

-24- 02 14/95

7/28/2019 1650167

32/75

Table - Coal Analysis

Remarks: Dulong's = 14,381Btu/lb

W3687WCA -25- 02/14/95

7/28/2019 1650167

33/75

The general procedure used fo r limestone reactivity measuremen ts is+200 mesh. Th is size cut was chosen because the specific surfacearea con tained provides good weight response over a wide range ofstone activities. Then using a specially modifid TGA, the samplewas c d c ~ dnder nitrogen and immediately sulfated isothermallyat P,550QFunder an W i c i atmosphere. Th e synthesized gass u l k d ioxide and thethe stme sample duringto provide data related to

as follows: Th e sample was first ground and screened to -100 mesh

The limestone was fairly low in calcium and the ASTlM as h yielded79.7 percent CaO. TGA sorption results indicated that the stone hada moderate reactivity. Based upon the limes tone analysis and th eTGA sulfation weight gain, one limestone had a 37.3percentcalcium utilization in the TGA. Th e TG A calcium utilization isusually greater than 50percent for high reactivity stones and lessthan 30 percent fo r poor reactivity stones.A Rosin-Rammler plot indicates that the limestone size distributioncontains a considerable amount of fines (21Spercent less than200mesh), even though the D50 is about 600 microns.The hardness of this limestone was qualitatively assessed using theHardgrove test. The limestone would be classified as moderatelysoft because it had an HI of 80. The change in sorbent particle sizeafter calcination was also evaluated in a static bench-scale test. Thelimestone was first screened to obtain a 16 x 20 mesh size fraction?then calcined in a muffle furnace at 1,600'F fo r one hour. Aftercalcination the limestone was screened again to assess the ex tent ofdecrepetation. This limestone showed only minor breakdown uponcalcination and about 5percent of the calcine passed a 20meshscreen.

d. TestResultsMany of eke issues to be n s o h e d by the pilot plant test burnrequired exten periods of exposerre, concentration of species ordevelopment of equilibrium conditions. To meet these varied needs,a 100-hour continuous test was opted for instead of several shorterduration tests. The fust 24hours of the run were used forstabilization of the unit, while the final 76hows were used forperform ance evaluation. Conditions selected for initial operationwere chosen on the basis of experience gained from other fuels.During the course of the run, the primary operating parameters of

W3687WCA -26- 02/14/95

7/28/2019 1650167

34/75

temperature and air split were varied to d ocument their effect on u nitperformance and operation.Data collection for the run was performed periodically according tosamples of fuel, bed and baghouseash were taken

t samples were taken atfoW-hoW i n t e r ~ d ~ , w, t e ~ m w ,ressure and fluegas composition d tervals by thesupplementedthe data acquisition system and prov ide8 an ndependent check.At the conclusion of the run, all test data were reviewed andanalyzed for stability. Representative test periods w ere then selectedfor perform ance evaluation. Follow ing chem ical analysis of thesolids samples from these periods, mass balance and efficiencycalculations were made. Th e hourly quart fuel sam ples taken fromthe coal silo were found to be consistent in both carbon and sulfurconten t (average 76.2 and 1.37 percent, respectively).The coal rate for this test was held between 300 and 3401b/h,corresponding to a heat input of up to 4.5 x 106 Btu/h. The bedtemperature was varied from 1,550"F to 1,650'F in order to assessits effect on unit performance. Primary air stoichiomehy wasmaintained at between 60 and 75percent for the test run. The totalair rate (coal feed air, primary air and secondary air) was set toachieve a superficial gas velocity in the freeboard of about 2Ofqs.The target sulfur captulre was 92percent for the entire test run.

Carbon combustion efficiency data values were computed using acarbon balance which excluded carbon monoxide in the flue gas.The carbon content of the coal was very consistent throughout thetest run (75.2 to 77.3 percent) and BR average d u e of 76.2 percentwas used for efficiency calculations. "he carbon loss from thesystem was com putedh m he 'e carbon conten t in the hourlybaghouse ash sar rpks and a use ash rate averaged for aneight-hour period mound be set point.

W3687WCA

The carbon combustion efficiencies ranged from about 88 to93percenk. Combustor temperature was found to have a significanteffect on carbon conversion. Th e average combu stor temperaturewas obtained from thermocouples placed at about 1 0 4 intervalsalong the height of the combustor. A maximum combustionefficiency of about 92 to 93percent was obtained at an average

-27- 02114/95

7/28/2019 1650167

35/75

combustor temperature o between 1,600"F and 1,625"F. Asignificant increasing carbon conversion should be obtained in ac om e r e id - sc a l e CFB compared to the pilot unit due to the longergas n=sidence time (5 vs. 2 seconds). For example, 5 to 6 percenthigher combustion eficiencies have been obtained in~~~~~~-~~~~units ~ornpwdo &e pilot plant when firing th es m ~~~~~ coals.

Average CO, NOx, N20 and S emissisns or&e test interyals i nboth the molar concentrztions and their equivalent emissionsin lb/106 Btu have been corrected back to 39percent 02. Thiscorrection corresponds to 22percent excess air (excluding unburnedcarbon) and was made to compensate for significant in-leakagewhich occurred during the test.Carbon monoxide emissions ranged from about 0.12 to 0.26 lb/106Btu and were strongly dependent upon combu stor temperature. TheCO em issions were reduced by about 50 percent as the combustortemperature was increased from 1,525"F and 1,625'F. Therelatively low carbon monoxide emissions (at higher temperatures)tend to indicate that carbon loss was not a result ofcombustion-related problems such as poor mixing within thecombustor. Instead, the carbon loss was probably a result of finechar which could not be completely burned in the relatively shortresidence time and elutriated from the cyclone.The target sulfur capture for the test run was 92percent. The sulfurcapture ranged from 89 to 95percent at CdS ratios ranging from 2.5to 3.8. An average coal sulfur content of 1.37 percent was used inthese calculations. At bed temperatures greater than 1,625"F7a Ca/Sratio in excess of 3.5 was required to obtain sulfur capture levelsgreater than 90pe rcent. Significantly lower Ca/S ratios wererequired at lower bed tem peratures to obtain in excess of 90 ercentsulfur capture. For bed temperatures bem een 1,600"Fand 1,625"Fa Ca/S ratio of about 2.8 was re to obtain sulfur capture levelsbetween 91 and 93pexent. This relatively high Ca/S ratio wasprobably due to the moderate reactivity of the limestone, coupledwith the relative ow sulfur content of the coal (1.37 perce nt).Nitrogen oxide emissions (NOx) ranged from 0.10 to 0.21 lb/106Btu and were strongly dependent upon cornbustor temperature. TheNOx emissions increased substantially as the average combustortemperature was increased from abou t 1,525"F and 1,625"F. Nitrousoxide emissions (N20)were observed to decrease by almost a factor

-28- 02/14/95

7/28/2019 1650167

36/75

W3687WCA

of two over the same temperature range. Th e conversion of fuelnitrogen to nitrogen oxide and nitrous oxide as a function ofcombustor temperatme is consisteat with previous pilot plant datazcsbeecl with bitumkous coals. The nitrogen and nitrous oxideemis&ms am for set point periods with primary air stoichiometriesranging froin 60 to 34percent. Over this primary stoichiometryrang& emissirno increase with higher stoichiometries, whileN 2 0 emissions remain e s s e n W y consmL

No bed drains were required during the test rn o maintain solidsinventory, although several bed samples were i&en for analysis.Essentially all of the carbon loss from the system occurred fromcarbon elutriated from the cyclone.Although no bed drains were required to maintain solids inventory,substantial build-up of bed was observed during certain portions ofthe test run. However, the bed level fluctuated considerably due tochanges in set point temperatures and primary air flows. The bedlevel was observed to decrease considerably as the bed temperaturewas increased to 1,650"F due to the decomposition of sulfatedsorbent. Extended operation at lower bed tempe ratures and primaryair flows would probably have required continual bed drains tomaintain a specified bed level.Analyses were performed on bed and baghouse samples to determineleachable components by the Toxic Characteristics LeachingProcedures (TCLP). This procedure is used to sim ulate the leachingwhich a waste would undergo if disposed in a sanitary landfill. Theprocedure involved extracting the ground ash samples with diluteacetic acid ( O S N ) for 24 hours. The extract from the ash was thenanalyzed by inductively coupled plasma (ICP) analysis for thefollowing elements: As, Se, Hg, Cr, Cd, Pb, Ag and Ba. None ofthese elements were observed in the extract from the bed andbaghouse ash samples.The pH of the bed and baghouse ash samples in deionized water( 5 percent add95 percent m%Qwas also measured. The baghouseash had a slightly higher pl3 &an the bed ash (12.3 vs . 11.3). Basedon the ca;rbon-&e mmpositions of the bed and baghouse ashsamples analyses, the bed and baghouse ash samples contained 39.2and 32-1percent freeCaO, respectively.

-29- 02/14/95

7/28/2019 1650167

37/75

3.

W3687WCA

c. ConclusionsTh e pilot plant test program has dem onstrated the feasib ility of usingc e M coals and Limestones. Th e follow ing conclusions areprovided to s u m & = the fmdings of the test program:

Ckbon ~~~~~s~~~efficiencies of 89-93 percent were attained atHigherin the commercial plant because ofs betwem 1,520 and 1,620"F.

Bed inventory was main d skg hestone do ne, however,little or no bed drain was required over &e c o m e of the test.Trends observed during the test suggest that the commercial unitwill require some bed drain during operation.The sulfur capture target of 92p ercen t is readily achievable asevidenced by S O2 captures in excess of 93 percent in eight of thefifteen test set points. Ca/S ratios of 2.4 to almost 4 wererequired due primarily to the less than average stone reactivityand the friab le natu re of the stone.NOx and CO emissions should not present any permittingproblems.No operational problems were encountered, i.e., bedagglomeration back and fouling.

Coal Handling and StorageWashed coal would be delivered to the proposed facility via rail car.The rail cars would be unload& inside the c oa l d o a d h g build ing (acompletely enclosed structure) where the coal wodd then be conveyedto storage silos. All coal trandw wodd occur via enclosed conveyors tominimize nois o s m to r a b f d l . A 30,000-tonsd WOMMe maintained in five 56 f tFrom the storage silos, the coal wouldconveyance to the boiler house. Use of anendosed C Q ~ V ~ ~ Y I C ~d storage system would minimize the potential

emissions and solids discharge in stormwater runoff.for a fuel handling process flow diagram.

Bituminous coal is delivered to the site by rail and is stored in five 56 f tdiameter coal storage silos with a 14 day storage capacity. The 2" x 0

-30- 02/14/95

7/28/2019 1650167

38/75

size raw co al is then conveyed to crushers to be crushed to 1/2"x 0 sizeand stored in 4 in-plant coal silos. The crushed coal is extracted fromthe silos at variable rates, as required by the ACFB boiler, bygravimetric %&rs and fed to both front and ear walls of the boiler.

b.

C.

d.

e.

f.g .h.

One r C3.r t with pla&a, platen hooks, andrings, mechanical: car dmps and tower, spill tmss, rear truss,trunnions, trunnian support beams, 2speed drive motor, drivechains, speed reducer, gear boxes, and c ar prosition sensors.On e traveling hamm ermill complete with drive motors, shafts, andcouplings, coupling guards, speed reducers? traversing rails, steelsupport frame, hamm er shaft, and hammers.Limit switches, clamp position sensing and/or indicting devices,solenoids, speed switches, slow down switches, over-travel switches,stop switches, equipment space heaters, etc., necessary for theoperation of the rotary car dumper and traveling hamm ermill.Proximity detectors or other devices required to sense, detect, orindicate the position and presence of cars on or in proximity to therotary car dumper.A minimum of four mushroom-head pushbutton emergency stopswitches.Electrically operated brakes as an integral part of motor.An alarm horn and flashing beacon lights.Design criteria for rotary car dumper.1) Dum per thrust wedges shall be designed for longitudinal thrustfrom an accelerating or decelerating locomotive up to150,000 pounds,2) The otary ciag dumper s f i d be designed for the following trainlo&.

a) Fully loaded, 4-axk, rotary coup led railcar:125 to 150 tons (maximum gross weight on rail:286,000 lbs.)

W3687WCA

b) Fully oaded, 4-axle, random railcar:

-3 1- 02f 14/95

7/28/2019 1650167

39/75

75 to 150 tonsc) Main line lomrno the with 6 axles:up to 195tom

3) Dum per shall be &sigmd &Imake it as regab le and trouble-freeas possible. It shall be such that dl parts subject torenewal or repair are

4) The dumper shall accommodate the dumping of coal into thedumper hopper by 25ton dump trucks as shown on thereference drawings. This may require rnuving the end rings intoward the center of the dumper.5) The dum per shall have a side wall that extends from 2-9' ' abovethe top of the rail to a minimum of 13'-0" above the top of therail and is a minimum of 50'-0" long. It shall support a loaded

car on its side and distribute the load uniformly along the sideof the car. Each end of the side wall plate shall have a cardeflector to correct minor misalignment of cars.Locomotive and Railcar Data:a. Coal will be delivered to the site via unit trains which consist of80-100 open top, rotary-coupled railcars. The unit train w ill beseparated into 20-car sections which will be maneuvered onto therotary car dum per with a main line locomotive.b. Dumper design shall accommodate the following range ofdimensions for the railcars and locomotives:

1) Fully loaded, 4-axle, rotary coupled railcar:- height of box above rail: 13'-0"- height, top of rail to center of rotation of couplers: 2-9' '- maximum overall width: 10'-7*'- length of box: 47'-h0" to $8'-4'"- pulling face to pulling of couplers: 43'-

2) Main line locomotive with 6 axles:-- heightfrom tap ofrail: up to 15'-9"width (when trimmer): up to 10'-8"

W3687WCA -32- 02/14/95

7/28/2019 1650167

40/75

3) Fully loaded, C axle , random railcars:- height fimbop of& up ia 13'-0"

length of bx: W-?Yb47'-90"- width: 10"-Y-HiPh An d e Convevoma.

b.

C.

d.

Three sandwich-type, high angle, silo ~ ~ ~ ~-2, C-4, andC-5 including a local control panel, and a steel frame struciure fo rsupport and enclosure. The steel support stmctwe shall includestairs and access platforms.One externally mounted, 4-person capacity elevator with open rackand pinion drive arrangement, support steel, and controls. Theelevator shall have two entry doors on adjacent sides and will beinstalled next to conveyor C-2.Head chu te, transition chutework, flop g age, support stee l, stirs, andaccess platforms at the discharge end of conveyor C-2.All locally mounted control and safety devices such as beltmisalignment switches, emergency pull cord switches, underspeedswitches, plugged chute d etectors, limit sw itches, etc.

SiloFeed Conveyor C-2a.

b.

C.

d.

Silo feed conveyor C-2 shall transport coal from the discharge of thechute work at the head end of conveyor C-1 to the transition chutework at the tail end of conveyor C-3A, at a rate of 2,000 TPH, withup to 10percent frozen lumps sized approximately 12xl2"x18",without spillate and w ithout causing dam age to any part.The conveyor shall be capable of stopping and restarting under anyloading conditions, i.e., empty, fully loaded, or partially loaded.Hugg ing pressure shall be app lied to &e material along the conveyorpath to develop sufficient friction, with m appropriate safety factor,to prevent material slide back The material cross-sectiondetermined shall allow ample belt edge distance to completelycontain the material within the belt sandwich. Th e installedconveyor shall acco ate all associated appurtances such asfeeders and discharge chutes*The conveyor shall convey the coal vertically (90" from thehorizon tal) withoaf m aterial slippage.

W3687WCA -33- 02/14/95

7/28/2019 1650167

41/75

Collection Conveyor C-4a.

b.

C.

d.

Collection conveyor C-4 shall trmspa~d oal from the five beltfeeders below the concrete cod storage silos to the surge binslocated in the crusher building sag a rate of 258 TPH, with up to10 percent frozen lumps sized x h at e ly 6"x6"x12", withoutspillage and without causing darnage tomy pu t .The conv eyor shall be capable of stopping md restating under anyload ing conditions, Le., empty, fully loaded, or p l 0 d dHugging pressure shall be applied to the material alo ng the conveyorpath to develop sufficient friction, with an appropriate safety factor,to prevent material slide back. Th e material cross-sectiondetermined shall allow ample belt edge distance to completelycontain the material within the belt sandwich. Th e installedconveyor shall accommodate all associated appurtances such asfeeders and discharge chutes.The conveyor shall convey the coal vertically at a 45 " angle ofinclin e without material sliding back on the belts.

Conveyor C-5a.

b.

C.

a.

Conveyor C-5 shall transport coal from beneath the crusherdischarge chutes to drag chain conveyor C-6 located in the conveyorroom of the Boiler Building, above the implant coal storage silos, ata rate of 250 TPH.Th e conveyor shall be capable of stopping and restarting under anyloading conditions , Le., empty, fully loaded, or partially loaded.Hugging pressure shall be applied to the m aterial along the conveyorpath to develop sufficient friction, with an appmpriate sa8ety factor,to prevent material slide back. T he cross-sectiondetermined shall allow ample be to Completelycontain the material within the sandwich. The installedconveyor shall accommodate all associated appurtances such asfeeders and discharge chutes.The conveyor shall convey the coal at cr 45" ngle of incline w ithoutmaterial s liding back on the belts.

W3687WCA -34- 02114/95

7/28/2019 1650167

42/75

Fuel Handling Area

W3687WCA

a.

b.C.

d.

e.f.

h.1.

j.k.1.

m.

n.0.

One car dumper happer with grizzly and dumper enclosure withcontrol room.Two d rag chain type @CF-1 md2).One car dumper mnveym (C-1) with belt scale andmagnetic separator.Four cascade conveyors ((2-3) including a locd control panel,support steel, and controls. The support steel shall include stairs andaccess platforms.Five slide gates under the fuel storage silos.Five belt feeder su nder the fuel storage silos.Magnetic separator at the discharge of HAC collection conveyor(C-4).One 50-ton capacity surge bin with two slide gates.Two vibrating feeders.Two 300 rpm cage mill type coa l crushers.One d rag chain conveyor (C-6) with discharg e gates.Dust collection systems equipped with pulse jet type fabric filter(s)at car dumper and conveyor transfer points. Vent filters for fuelstorage silos and a insertable dust collector at discharg e of conveyorc-5

Hoists and trolleys for maintenance pof the fuel handling system.Ventilation system.Heating pads to the cmtmwalls of the rotary car dum per hoppers andstorage silos.

The Fuel Handling System shall be designed to meet the followingdesign ca pacities requirements.a. Coal unload ing and storage system - 2,000 TPH.

-35- 02/14/95

7/28/2019 1650167

43/75

b. C oal crushing and n x h h h g system - 250 TPH.StorageAreaa. Five (5 ) reinforced canaete fuel storage silos complete withconcrete roof and stainless discharge hopper. Th e cone ismounted on a ring girder syste mb. A reinforced concrete common mat for sqwor t of th efive silos including a topping slab with curb atad al requiredexcavation, subsu rface preparation, and bac kfill work.Construction Features:a.

b.

C.

The silos shall be designed for a fuel storage capacity of220,000cubic feet per silo and shall be of cast-in-place concreteconstruction. A clear space shall be maintained between each silo toallow for independent wall construction by either the slipform orjumpform m ethods.Each silo shall be equipped with a com bination carbon and stainlesssteel discharge hopper.The steel discharge hoppers shall be attached to and suppo rted by areinforced concrete ring beam at the walVhopper transitionelevation. The concrete ring beam shall be suppo rted indepen dent ofthe silo walls by reinforced concrete columns extending down to thetop of the foundation.

4. Ash Handling and StorageThe CFB combustion process utilizes coal and limestone in the boiler.After combustion, the resulting limestone ash by-pmajluct materialcomes from two areas: bottom ash material from theCFB boiler and flyash material from th e pollution control equipment @o&r baghouse).The bottom ash and fly ash material w a d d be conveyed separately toon-site enclosed storage silos with a r& d cqac5ty of approximately3,100 tons. Th e ash handling system would include ash conditioningequipment located in the ash silo The ash conditioning equipmentwould be used to dampen the ash with watw prior to loading it intototally enclosed 25 ton net capady trucks in order to minimize thepotential for fugitive du st epslissions d;afing ash handling. The truckswould be used to haul the ash material from the site to a surface minereclamation site in S ch uy H d County.

W3687WCA -36- 02/14/95

7/28/2019 1650167

44/75

A rnulti-compartment baghoazse filrer system will be used to clean theflue gas exiting the * and seconday air heaters. The baghousep d c u l a t e s in the flue gas and0.011 lbs/MM Btu. A design air-

with me compartment isolated fort fo r Pndinteramce. Each baghousewill be discharged to

to-cloth ratio of t

the fly ash removal system.Ash DisDosa SystemThe cooled bed ash will be conveyed to a bed ash storage silo via apneumatic transport system. The bed ash collected during the pilot planttests will be used to test differen t ash transport systems to determine themost reliable and cost effective transport system for the bed ash. Thefly ash is conveyed from air heaters, economizer, and baghouse hoppersby dilute-ph ase pneum atic transport system to a f ly ash storage silo.

5. Chemical Handling and StorageAs part of the proposed cogeneration facility operation, chem icds (forwater treatment) and lubricants (for mechanical equipment upkeep)would be used and stored on-site. These materials would include oi l andgrease, diesel fuel, solvents (for degreasing equipment), caustics andsulfuric acid, water treatment chem icals, and aqueous am monia.Aqueous am monia (29 percent solution) would arrive at the facility bytruck at an estimated frequency of one delivery per week. The ammoniastorage tank would be located within a fully contained and dikedconcrete area providing sufficient secondary containment of the storagetank to pre ven t a release.

6. Limestone Handling and StoragePulverized limestone wmld be delivered to the facility in 20-toncapacity enclosed trucks, is currently determining the necessarylimestone specifications. ~~~~~e~me expected to be generally locatedwithin a 50 -mile radius of the proposed Site, with one potential sourcelocated approximately 1 miles from the site. The limeston e materialwould be pneumatically (& blown) transferred from the trucks into astorage silo. The silos would be sized to provide an approximatelyfive-day supply of limestone (1,870 tons). The limeston e materialwould then be pneumatically transferred from the storage silo to the day

W3687WCA -37- 02f 14/95

7/28/2019 1650167

45/75

7.

W3687WCA

bins in the boiler house. From the day bins, the material would be feddirectly into the CFB boiler for use in SO2 emissions control. Bytransferring the material via enclosed s s bhe potential for fugitivedust em issions would be minimized.Depending on the source of the raw lime te, the sorbentwould be either delivered by pneumatic mashed at an adjacentsite and pneum atically conveyed to two sorbent silos. Each silodischarges to on (1) 100% capacity gravimetric belt feeder. From thefeeders, the sorbent is dropp ed into a bifurcated discharge hopper w herethe sorbent is divided into two streams. Four (4) 50% capacity sorbentblowers convey the so rbent to the ACFB boiler pneumatically and injectit to th e boiler at the vicinity of coal feed points. The rate of sorbentfeed is au tomatically adjusted if the SO2 concentration measured at th estack exceeds a predetermined set point.TurbineThe YC EP facility will generate electric power by extracting shaft workfrom the high pressure superheated steam flow produced by the ACE3steam generation circuits. The turbine generator system includes high,intermediate and low pressure steam tmbinp,s connected to a generctor.The turbine will be equipped with 8 extraction points to service thefeedwater heaters, reheat system, and export steam. Exp ort steam (up to400,000 Ib/hr) at 575psig and 670 F will be sent to PHG where it willbe integrated with their existing steam system.The steam turbine includes:Steam Turbine:Combined HP-IP steam turbine, solid-coupled to L P tu rbineDouble flow LP steam turbine with bottom down exhaust, d id -co up ledto generatorOne set of cross-over piping between IP and LPElectro-pneumatic power-assisted non-retuna check valves for allextractions, including two parallel NR check valves in the extraction tothe first L P h eater and two series NR check valves in the extractions toboth the 5th and 6 th heaters.Electric motor or electro-pneumatic actuated non-return stop valves forall extractions, including two parallel Nw stop valves in the extractionfrom the first LP heater

-38- 02/14/95

7/28/2019 1650167

46/75

Blowdown co vers for throttle and eheat stop valvesProtection and control valve systems including:DC S-based eme