evaluation coal conversion process

8/3/2019 Evaluation Coal Conversion Process

1/80

EVALUATION OF COAL CONVERSIONPROCESSES TO PROVIDE CLEAN FUELS

Final Report

Donald L.,Katz, Dale'::S.Bri'ggs,..:;;.', ", 'Edward,R,. Lady ,John E., :Powers,M. Rasin,+ek, BiymerWi11lams,Walter ,'E;Lobo tCons~lt'ant)

EPRI 206-0-0Final ReportPart I

Prepared Under Research Project EPRI 206-0-0 by

THE UNIVERSITY OF MICHIGANCOLLEGE OF ENGINEERING

ForELECTRIC POWER RESEARCH INSTITUTE

Palo Alto, California

February 1974


2/80

EXECUTIVE SUMMARY

A substantial quantity of high quality research anddevelopment has been found in converting coal to cleangaseous and liquid fuels as well as general coal utiliza-tion in environmentally acceptable ways. ,A multitude oforganizations in the United States have been working formany years on these processes, some up to 25 years. Thevariety of programs indicate the complexity of utilizingcoal to meet fuel needs and to provide environmental safe-guards.

The mix of coal, fuel oil and natural gas presentlyused, the geographic location of coal supplies and otherresource needs relative to plant locations and the varietyof processes potentially capable of meeting environmentalrestrictions, indicate that no single process for coalconversion or use for electric power generation can beexpected to be a panacea. Many processes now under develop-ment have the potential to reach commercial scale under theright conditions. Research and development support istherefore recommended in fluidized bed combustion, chemicalbeneficiation, coal gasification and coal liquefaction. Supportis encouraged in pyrolysis and insitu combustion.

It should be recognized that the electric power industry'sneeds for acceptable fuels from coal parallel those of thenatural gas industry for high Btu gas production from coaland the petroleum industry for crude oil production from

ii


3/80

coal. We believe that coal gasification and liquefactionplants will be commercialized and serve the three industries.Fluidized bed boilers, pyrolysis, and chemical beneficiationfor certain coals will have their places. Commercial applica-tions are not anticipated before 1980. Research and develop-ment which builds upon what is already known and moves inthe direction indicated by changing economic and regulatoryconditions is vitally needed.

All coal conversion or utilization processes which donot have, at least, short term storage will have potentialcoupling problems between the fuel production and the powergenerating system utilizing the fuel. Underground storageof low or intermediate Btu gas,possible in certain geographicallocations, could permit independence between those two coupledsystems.

Clean low or intermediate Btu gases will be less costlyto produce than high Btu substitute natural gas, but becauseof transportation costs should be produced close to thelocation of utilization. These gases should be ideal fuelsfor combined cycle systems.

The overall heat rate from coal to electricity forcombined cycle plants fired with coal derived gases orliquids cannot match conventional power plants with stackgas clean-up at present. Combined cycle turbine developmentswhich permit higher operating temperatures could have lowerheat rates than conventional plants. Turbine developmentsare therefore to be encouraged.

111


4/80

Fluidized bed combustion has intriguing possibilities.The boiler installation, itself, should be smaller and lessexpensive in first cost than conventional boiler installa-tions with or without provisions for sulfur removal. Amajor problem appears to be the disposal of unused calcinedlimestone which accompanies the calcium sulfate when lime-stone is used on a once-through basis. Chemical regenera-tion of limestone with production of elemental sulfur ismany years away from commercial development.

In view of the fact that there are coals available withlow organic sulfur and high pyritic sulfur, chemical benefi-ciation has a place in converting such coals to an acceptablefuel on the basis of sulfur emissions. It would seem worth-while to develop chemical cleaning systems if they showpromise on the basis of reliability and economics.

Finally our study has indicated that there are a numberof ancillary problems which are common to many of thesystems being proposed for the production of clean coalsand work on these should be considered. High priority itemsare methods of feeding of coal into high pressure systemsas a powder or as a slurry, coal slurry pumps, pressure let-down valves for liquids containing solids, high temperaturegas particulate cleaning systems, oil-solids separationsystems and the production of hydrogen or a hydrogen richgas from coal, char or coal residue. Control systems shouldbe developed along with the processes to promote safety andreliability.

iv


5/80

Our recommendations for research and development supportare given in the following table. The recommendations aredivided into four categories--fluidized bed combustion,coal gasification, coal dissolution and liquefaction andbeneficiation. Work should be supported in each category.The items listed in each category are in the order ofendorsement. As in all research and development programs,processes must be regularly evaluated and research manage-ment must be prepared to terminate support selectively,where projections are not satisfactory, or where, amongcompeting processes the success of one eliminates need fordevelopment of others.

v


6/80

RECOMMENDATIONS FOR RESEARCH ANDD EV EL OP ME NT S UP PO RT

Fluidized Bed Combustion1. Support fluidized bed combustion boiler developmentat atmospheric pressure2. Support work in disposal of wastes (lime, fromfluidized bed combustion)3. Support research in limestone regeneration

Beneficiation1. Support the TRW chemical beneficiation process toextract sulfur from pyrite in coal

C oa l G as if ic at io n1. Support the Combustion Engineering 120 ton/day atmos-pheric pressure gasifier pilot project2. Support the gasification of liquid or solid wastesfrom coal dissolution processes at pressure in aKoppers-Totzek type gasifier to produce hydrogen

for coal liquefaction3. Support Foster-Wheeler's 1200 ton/day low Btu -combined cycle power generation system4. Support a molten salt gasification process at pressure

Coal Dissolution and Liquefaction1. Support the Hydrocarbon Research, Inc. H-Coal ebullat-

ing bed, catalytic coal liquefaction process2. Support continuation of the Wilsonville Process Develop-ment unit3. Support the development or high temperature slurrypumps and pressure let-down methods by equipmentmanufacturers

Vl.


7/80

TABLE OF CONTENTS

TITLE PAGEE XEC UT IVE SU MMA RYTABLE OF CONTENTSLIST OF TABLES AND FIGURESFOREWORDACKNOWLEDGMENTSPART I - EVALUATION OF COAL UTILIZATION PROCESSES FORCLEAN FUELS

IntroductionConduct of the ProjectCoal Conversion ProcessesBases for Comparison of Processes forClean Fuels

Scale-up and Time to CommercialOperationComplexity, Reliability and SafetyAdaptability to Utility UseTurn-downThermodynamic EfficiencyEnvironmental ConsiderationsE co no mi c E va lu at io nJudgementComparison to Stack Gas Cleaning

G en er al O bs er va ti on sInstitution RestraintsCommon Interest with Gas and OilIndustriesNeed for National Priorities andAllocationsUniversity and Institutional SupportAttention to Coal MiningConsideration of Tall Stacks

vii

iiviixiXllxv

138

15

16

171921232425292931313133333535


8/80

TABLE OF CONTENTS (contd.)

E~aluation of Various Routes to CleanFuels and Recommendations 37Fluidized Bed Boilers 37Beneficiation 39Pyrolysis 41Coal Gasification 42Coal Dissolution and Lique-faction 46Insitu combustion 49

Selected Bibliography - Coal Conver-sion Processes 50News Release 58

PARTS II AND III ARE UNDER SEPARATE COVER

PART II - CRITICAL REVIEW AND ASSESSMENT OF COALUTILIZATION PROCESSES FOR CLEAN FUELSIntroductionFluidized Bed Combustion

Review and AssessmentBibliography

BeneficiationReview and AssessmentProcess Descriptions

TRW's - Meyer ProcessBibliographyPyrolysis

Review and AssessmentProcess Descriptions

FMC - COEDOil Shale Corp. - TOSCOALGarrett - Flash Pyrolysis

Bibliographyviii


9/80

TABLE OF CONTENTS (contd.)

C oa l G asi fi cat io nReview and AssessmentProcess Descriptions

LurgiKoppers-TotzekWinklerBituminous Coal Research -Bi-GasCombustion EngineeringFoster WheelerAtomics International -Molten SaltM.W. Kellogg - Molten SaltGasifieru.S. Bureau of Mines -Stirred Bed Gasificationu.s. Bureau of Mines - Synthaneu.S. Bureau of Mines - HydraneBattelle - Ash AgglomeratingGasifierCity College, City University ofNew York - SquiresIGT - U-GASIGT - HYGASWestinghouse - Advanced GasifierConsolidation Coal - CO2 AcceptorBrigham Young - Entrained BedGasifierTexaco - Partial Oxidation ProcessShell - Partial Oxidation ProcessBituminous Coal Research -Fluidized BedApplied Technology Corp. - ATGAS

BibliographyCoal Dissolution and Liquefaction

Review and AssessmentProcess Descriptions

ix


10/80

Hydrocarbon Research, Inc. -H-CoalPittsburg & Midway Coal MiningCompany - Solvent Refined CoalSouthern Services, Inc. - SolventRefined CoalGulf R&D - Gulf Catalytic CoalLiquidsU.S. Bureau of Mines - SynthoilConsolidation Coal Company -Consol Synthetic Fuel

BibliographyInsitu Gasification of Coal

Review and AssessmentBibliography

PART III - RElATED TOPICS IN COAL UTILIZATIONThe Combined Cycle in Relation to Coalas a FuelEconomic EvaluationCapability of Existing Electric Genera-tion Units to Use Clean FuelsThermodynamic AnalysisBlack Mesa Coal Slurry PipelinesNews Release on Project

x


11/80

TABLE I

TABLE II

TABLE III

TABLE IV

TABLE V

FIGURE 1

LIST OF TABLES

Summary of Interviews, Site Visits,and Conferences on Coal ProcessingMeetings and Symposia Attended withPrograms Relevant to StudyReports and Meetings Held with SponsorRepresentativesCoal Conversion Processes Reviewed forEvaluationClean Fuel Process Development Programs

LIST OF FIGURES

Alternate Routes to Coal Utilizationfor Electric Power Production

xi

Page5

7

7

9

12

11


12/80

FOREWORD

The Task Force on Coal Utilization of the ElectricPower Research Institute approached The University inMarch 1973 to assess the various processes which convertcoal to clean fuels or utilize coal in environmentallyacceptable ways for electric power generation. A prelim-inary proposal was submitted to Mr. Larry Simpkin onMarch 30, 1973 suggesting a l4-month study. After reviewand discussion, we were advised that EPRI's need was fora study to be completed by January 1974. Accordingly,the final proposal submitted on June 6, 1973, was for one-half the time and budget originally suggested.

The University of Michigan Team received oral reportson the stages of approval of the proposal and startedpreliminary studies on July 16, 1973. The Board ofDirectors of EPRI approved the proposal on August 15, 1973.The final contract agreement was signed by EPRI on October24, 1973 and by The University on November 13, 1973. Anews release, approved by EPRI, was issued by the Universityon August 24, 1973 and is given on page 58.

The seven-month study was very intensive; membersof the team had teaching responsibilities for a sUbstantialfraction of their time during the study in addition to theproject work.

xii


13/80

The results of the study of coal conversion processeswere divided into two volumes: Part I and Parts II and III.In this way, the recommendations for support to the ElectricPower Research Institute (Part I) are separate from thecritical review and assessment of the coal utilizationprocesses being developed in the nation (Part II).

Part I was prepared specifically to assist the ElectricPower Research Institute management in the preparation ofa long term research program in coal utilization on behalfof the electric power industry. Part I contains the choicesand recommendations for research support by EPRI. Thoseprocesses which seem to have the best prerequisites forproviding clean fuels from coal at the earliest dates weredelineated. The bases for and the reasoning behind thechoices are given.

Part II contains the process descriptions and generalevaluations of some thirty-seven processes which are reviewed.The team of investigators reviewed and studied reports andresearch proposals for the processes. Personal visits weremade to the organizations carrying out the research anddevelopment and to the sites where the experiments are beingconducted at bench, process equipment development unit andpilot plant stages. The organizations were very cooperativein providing information and generous with their time inanswering our questions. Several organizations providedfurther supporting information requested by telephone orletter after our visits.

xiii


14/80

The description of the processes is intended togive members of the electrical utility industry an overallunderstanding of processes and is not intended to transferdetailed technical knowledge in a thorough manner. Refer-ences are cited for the more complete descriptions avail-able to the team. It is from those references that theinformation given has been extracted. The understandingdeveloped by the team and documented in Parts II and IIIof this report provided the basis for the evaluationrendered in Part I.

Part III contains several topics which are importantto coal utilization although not actually coal conversionor utilization processes. These topics were added to givegreater perspective to the general subject of coal use.

The authors for the several process descriptionsor sections are listed. Dr. D.E. Briggs managed andedited the final reporto

Donald L. KatzFebruary 1973

xiv


15/80

ACKNOWLEDGMENTS

We acknowledge the time and thoughtful comments freelygiven by the many individuals in the organizations visitedduring this project. We appreciate their help sincerely.

We were assisted in this work by the following graduatestud~nts in chemical engineering:

Michael W. BrittonAndre W. FurtadoDavid E. HammerGerald D. HolderJ. Andrew StirlingEdward E. Timm

We hope their experience has been as interesting as ours.

xv


16/80


17/80

PART IEVALUATION OF COAL CONVERSION PROCESSES


18/80


19/80

EVALUATION OF COAL CONVERSION PROCESSES

The initiation of this project is described in the fore-word. The goals of the project were to investigate the on-going research and development programs on coal conversionto clean fuels and coal utilization in environmentallyacceptable ways for electric power generation, and recommendto EPRI those processes whose development warrants accelera-tion through EPRI's support. The conduct of the investigationis described with some general concepts and observationsmade during the seven month study.

We were aware that the study of the many processes inseven months would be difficult and that process assessmentwould often be a matter of judgement. An attempt was madeto gather information on basic thermodynamics, rate processes,and chemistry associated with the processes under considera-tion. To develop some understanding of the processes, flowsheets with process conditions, material and energybalances, results of experimental programs and plans for thefuture were acquired through reports, papers, interviewsand personal visits. Generally, processes go through threeor four development stages of increasing size before reach-ing commercial size. In the early development stage, plansare usually announced for the next larger scale developmentin proposals soliciting support. Based on the writteninformation gathered and interviews, an assessment was made

1


20/80

2of 37 processes or topics and is given in Parts II and IIIof this report, which are bound separately.

The evaluation took into account the nature and require-ments of the electric power industry. Factors such aspotential cost, efficient fuel utilization, reliability,complexity, environmental considerations and stage of develop-ment were therefore of prime importance.

Finally, the various routes, coal beneficiation, gasifi-cation, liquefaction and fluidized bed combustion werecompared and evaluated with regard to their potential integra-tion into the electric power industry.

It is quite clear in the energy picture that what isdone or not done is often more a result of institutionalrestraints rather than technological developments. Leader-ship by government and industry in managing these restraints

is vital if the technological developments are to servetheir intended purposes.


21/80

CONDUCT OF THE PROJECT

It was intended that members of the Team would visitthe sites of coal conversion projects and interview theinvestigators. From the general literature, the reportsof the Office of Coal Research, and discussions withrepresentatives of EPRI, the principal projects wereidentified. Before an interview was made at a researchand development organization, available reports werereviewed and a check list of needed information prepared.

Table I gives the list of conferences and interviewsheld. In nearly all cases, the visit was at the site ofthe development work. Our hosts were very generous withtheir time, and were helpful in supplying reports and/oradded information. A project library was established formaking the literature available to the Team for subsequentreview.

Members of the Team attended the meetings listed inTable II, at which coal conversion was a significantportion of the program.

A Letter Report was submitted to Dr. R.E. Balzhiseron November 5, 1973 as required by the contract. OnNovember 8, 1973, a meeting with representatives of EPRIand the Task Force on Coal Utilization was held to reviewprogress. On December 14, 1973, the Team met with thefull Task Force on Coal Utilization and three members of

3


22/80

4the EPRI staff. The recommendations by the Team from thestudy were given orally to representatives of the TaskForce on January 10, 1974 along with preliminary draftcopies of the final report. Dr. Dale Briggs made a presenta-tion to the Task Force at Atlanta, Georgia on January 16,1974. These occasions for reporting to the sponsor are listedln Table III.

During the course of this study we also visited organiza-tions and studied processes for which no recommendation ismade in this report. There are processes which are well-supported financially and no additional assistance is needednow, and there are processes which have not yet reached thestage where added outside support will speed the developmentsignificantly. All processes which have been visited are des-cribed to some extent in Part II. There are also severalprojects which we could not visit owing to the limits on ourtime. As far as we know, these projects, where publiclysupported, will come to the attention of EPRI in the future.


23/80

5TABLE I

SUMMARY OF INTERVIEWS, SITE VISITS,AND CONFERENCES ON COAL PROCESSING

OrganizationAir ProductsAtomics InternationalA zo t I sle tme le ri ,Kutahya, TurkeyB att ell e, C ol umb usBabcock & WilcoxBCURA Leatherhead, EnglandBituminous Coal ResearchBlack Mesa PipelineBraun, C.F.Brigham Young UniversityCatalytic, Inc.

C hev ron R es ea rc hCity College, City Univ-ersity of N.Y. (ArthurSquires)Combustion EngineeringCo mm on wea lt h E dis on

ConferenceDates---Aug. 16, 1973Oct. 24, 1973Nov. 1, 1973Oct. 19, 1973Oct. 29, 1973Nov. 5, 1973Aug. 17, 1973Sept. 28, 1973Oct. 25, 1973Sept. 22, 1973Aug. 16, 1973Sept. 20, 1973Dec. 3, 1973

Jan. 16-17, 1974Sept. 25, 1973Aug. 30, 1973

Consolidation Coal, Library Aug. 24, 1973Consolidation Coal, Aug. 27, 1973Rapid CityContinental Oil CompanyExxonFMC

Dec. 2-7, 1973Dec. 17, 1973Aug. 7, 1973Dec. 2, 1973Oct. 25, 1973

G arr et t R ese ar chGulf Research & Develop.Hydrocarbon Research, Inc. Sept. 19, 1973Inst. of Gas Technology Aug. 22, 1973

ProjectRepresentativesLady, PowersTek, WilliamsBriggsBriggs, Tek, WilliamsLady, Lobo, TekBriggsBriggs, Lady, PowersKatz, WilliamsTek, WilliamsWilliamsLady, PowersBriggsBriggs

PowersLady, Lobo, PowersLady, PowersBriggs, Tek, WilliamsLobo, Tek, Williams

PowersBriggs, KatzKatz, Lady, PowersBriggsBriggs, KatzBriggs, KatzBriggs, Tek, Williams


24/80

6TABLE I (continued)

Organization

Kellogg, M.W. (Houston)KoppersKoppers, Essen, GermanyNational Coal Board,Lon do n, Eng la ndN or th ea st U ti li ti esOffice of Coal Research(Neal Cochran)Oil Shale CorporationOklahoma State UniversityParsons, Ralph M., Co.P et ro le um T ec hn ol og yPittsburg & MidwayS he ll D ev el op me ntSou th ern Ser vi cesS te arn s- Rog er , I nc .TRW (Redondo Beach)U.S. Bureau of Mines,BrucetonU.S. Bureau of Mines,MorgantownU.S. Bureau of Mines(Sidney Katel1)U ni ve rs it y E ng in ee rsUniversity of UtahWestinghouseWest Virginia University

ConferenceDates ProjectRepresentative

Oct. 1 7, 19 73Sept. 28, 1973Oct. 3D, 1973Nov. 6,1973

TekBriggs, Lady, PowersBriggsBriggs

Sept. 25, 1973Dec. 19, 1973

Lady, PowersTeam in Ann Arbor

Oct. 19, 1973Dec. 2-7, 1973Dec. 2, 1973Dec. 2-7, 1973Aug. 23, 1973Dec. 2-7, 1973Aug. 9, 1973Aug. 27, 1973

PowersPowersBriggsPowersBriggs, LadyPowersBriggsBriggs, Lobo, Tek,Williams

T ek , Wil li amsBriggs, Lady, PowersBriggs, KatzBriggsLady, PowersTeam in Ann Arbor

Oct. 26, 1973Oct. 1, 1973Oct. 24, 1973Aug. 1, 1973Oct. 16, 1973Nov. 28, 1973

Dec. 2-7, 1973Oct. 16, 1973Oct. 2, 1973Oct. 15, 1973

PowersKatzBriggs, Lady, PowersPowers


25/80

7TABLE II

MEETINGS AND SYMPOSIA ATTENDED WITH PROGRAMS RELEVANT TO STUDYAug. 13-14, 1973Sept. 7-14, 1973Oct. 8, 1973Oct. 29-30, 1973Nov. 12-14, 1973Jan. 16-17, 1974

EPRI Coal Utilization Meeting,Washington, D.C., (Katz)IGT, Clean Fuels from Coal Symposium(Briggs)Canadian Gas Association - Calgary (Katz)AGA Symposium on Synthetic PipelineGas, Chicago (Katz, Powers)AIChE,Philadelphia (Briggs, Katz, Powers,Williams)City College, City University of New York(Powers)

TABLE IIIREPORTS AND MEETINGS HELD WITH SPONSOR REPRESENTATIVES

Dec. 14, 1973

Meeting of U. of M. EPRI Team withR .E. B alz hi serMeeting with Larry SimpkinLetter Progress Report to R.E. Balzhiser(11 pa ge s)Discussion of Progress Report withGeorge Hill, Larry Simpkin, JerryLanzolatta and Kurt Brenner in Ann ArborPresentation to and discussion with theTask Force on Coal utilization and withMessrs. Hill, Louks, and Alpert of EPRI,Ann Arbor (28 present)Presentation of recommendations toGeorge Hill and Larry Simpkin,Ann Arbor, MichiganPresentation of final recommendationsby Dale E. Briggs, M. Rasin Tek andBrymer Williams, to Task Force on CoalUtilization, Atlanta, GeorgiaReview of preliminary draft with EPRIstaff by Dale E. Briggs, Palo Alto,California

Aug. 2, 1973Oct. 5, 1973Nov. 5, 1973Nov. 8, 1973

Jan. 10, 1974

Jan. 16, 1974

Jan. 25; 1974


26/80

COAL CONVERSION PROCESSES

Coal conversion processes have been evaluated in themajor areas shown in Table IV; fluidized bed combustion,beneficiation, pyrolysis, gasification and liquefaction.Figure 1 shows the major areas and comparative informationfor these areas as they are known to date. An assessmentof the major areas, based on reports and interviews, isgiven in Part II of this report with process descriptions ofthe processes listed in Table IV. Table V gives a develop-ment status of some of the more advanced programs.

The development of some processes is supported bythe government directly, for example the Bureau of Mines.Some are part of the natural gas industry's program for sub-stitute natural gas from coal, and others are a part of thege ne ral pr og ram by petroleum companies to produce liquidsfrom coal. Certain developers have proposals pending orare in process of seeking support. EPRI should sponsor and/orsupport those processes or programs which offer the greatestpotential to the electric power industry and especiallythose programs which might lag for lack of governmental support.

8


27/80

9TABLE IV

COAL CONVERSION PROCESSES REVIEWED FOR EVALUATION

Fluidized Bed Combustion with Sulfur RemovalPope, Evans and RobbinsBritish Coal Utilization Research Assoc.Esso Research and EngineeringArgonne National Laboratory

Coal Beneficiation for Sulfur RemovalTRW's - Meyers ProcessSyracuse University ProcessU.S. Bureau of Mines Process

PyrolysisFMC - COEDGarrett - Flash PyrolysisOil Shale Corporation - TOSCOAL

Coal GasificationLurgiKoppers-TotzekWinklerBi tu min ou s C oa l R es ear ch --B i- GasCombustion EngineeringFoster-WheelerAtomics International - Molten Salt


28/80

10TABLE IV (contd.)

M.W. Kellogg - Molten SaltU.S. Bureau of Mines - Stirred Bed GasifierU.S. Bureau of Mines - SynthaneU.S. Bureau of Mines - HydraneBattelle - Ash A(:JglomeratingGasifierIGT - Ash Agglomerating Gasifier, U-GASSquires - Ash Agglomerating GasifierIGT - HYGASWestinghouse - Advanced GasifierConsolidation Coal - CO~ Acceptor

L.

Brigham Young - Entrained Bed GasifierTexaco - Partial Oxidation ProcessShell - Partial Oxidation ProcessBituminous Coal Research - Fluidized BedApplied Technology Corp. - ATGASu.S. Bureau of Mines - Insitu Combustion

Coal Dissolution and LiquefactionHydrocarbon Research, Inc. - H-CoalPittsburgh & Midvlay Coal Mining Company -

Solvent Refined CoalSouthern Services, Inc. - Solvent Refined CoalGulf R&D - Gulf Catalytic Coal LiquidsU.s. Bureau of Mines - SynthoilConsolidation Coal Co. - Consol Synthetic Fuel


29/80

11

: : : >. . . .ca

z0 en c ,c ~ 0 c;v, """ .~ ~cr

Vl e-, 0.2"'u '" "0 ~ :;:;t:iu- e :;) eoo~ ~ 'OQ;0:: V1 E - m '" :;)0- Vl c E ig5 c,u

-

B: : : >. . . .v o r o

'" Vl~i5~'~

Of>Of>'"Uo" "..

s : :0' r - !. w0;: 3- o0H~HO J~0c,0

' r - !H. w0~ O J)'u r-f:II> rL l'".sC H01;; 4-le.&c s : :c: 00 .r-!~ +Ja r OeQ NCl) ' r - !c: r-f0 ' r - !B +J; ) < J1 ; i 1 P Pc .0"u~ r-f~ ~J : 2 , s rO~.[ 0~ U. . . 0~.~ . w:l",u=c : :;) til-'" O J+J~0p ::

O J. wrOs : :HO J+Jr-f, r : : t :r-fO JH;: 3bI

' r - !~


30/80

12,....-' II

/6) --- f - - - IJ-, !c9 I wI

~ o C > (!) o o o

>-Ol.2 III I 010 Q) cc c :> . . ..c ~u ~ -g _0 cOl(f) o 0-t . < E QJ 00 o.~(f) 'Oro -:::J u~ .- . . .w (l) 1/1 - . . . . Q)U '0- :;)"0 0 0...... U 1fIQ) Q)- c(lJ III oQ. l ~JJI s: ~ '0 Be c . . . .-. 00 :.::0 Q)t 0'1> In E 'C t ~ ~$o . . . .0 :: 0..0'1 . . . . - - o u- .- .- e N 1 I I. s : : ; _ "00- : : 3 - . . . . c 00 oe )( 03:Q) >-o, < . 1 5 co~ C O rn C D Q'J:::J uu uw W IJ .. _ J:"'


31/80

13

.- o. . j . Jcoo

i i i! t6 > I iI i , 0 ; II0 6 > I I i j_ LI I t I01

6 "< ! j ul I; I t T ;6)< I s 01 II ;io l I II s I: 01 I r I.1 ~I~ < I

.. II I o J . . j_ 1 DI r i ~!.,t I 0 1 ul I" ' < I I ! II

~ 0; 0 ~ T T o l. 6 < ~J 1 001 I I u i i ; ra : sf'< 0 0.I

'~ 0 I< ' 6 " / - - + - - - JI s4 ' r I I~I~,g I ' . t-L0B. I I--~ I-.- 0&--- r-Wo ~ og 0 00 0( I,n 2 2 Z c0 ~ ~ V 1 .0 0 -00 rt')0N j : : : : f'.. _f'.. ~N 0 1 . 01 . 0 f'..~ ~ N --- -W . . . . . . ,_~ I

' .JC E E s: O J _ c : ; s: Q) Q)u...~ u _ w U fJ - ::J _ Q) Q) : : : IcE E E c: 0c: c c : : 0 '0 0e C "0W,_ 00 (j):=g Q) (I) -- IV :::: ,2 ,2 IVI D a . u umaCl. C D roa. o , 0.. a. a. a.f----- -f n - -I -N ~I r < >_ , -~ .---W .c ~ . . . . : . . . . : ...: ...: ...: . . . . : . . . . :~ I 0':l1J) 'in 'in 'iii 'iii ' e n 'iii 'iii 0- cr-_ 00 0 0 0 0 0 < 3-".!) o (!) t!) o o ...J ...J1-- ~ g JQ .I - - c WN - 01- 0_00 ~ I/) I/) c(f) ~ c: -0 ::J 0 0e n 00_ e Q ) 0 t!) '';::I 1/)'';:: (/)- . J : : . UUW III 1 11 C 01 - I ,- 0. . . c ,!::?o c~ : : : I 0 : : : : > - _ -o I/) w ,- III E E ~ s: or. ,~~ ~ 1:: 'w 00 t-0 0- 01 =: : :00> 111 - t- " --0: : : I 0a : : : (!)~ 0- . . . o 0_- ~~ ,_ C III(.)0 - - 0- U~ ::l :E U') 5. ::l >. ~ IV_ l') ::l 0-Q. HI ...J (Dcn O J Q) H l')U...J J:,: >


32/80

14

- o.jJ~oo

O~I~----~------r---+--+------r--I

~-o,

gl N

E.g~EQ).- 0a..a..u

.C>.-- -Q)(1)0:::III.000...uU.u"t:l

~ ~IJ.. U

Q):i s.9o>< X

C.2-u::J"0eo,

(/)wbz-I i : ! "->-"0::l-/) -CIII 0C0- o,_0, . . 1 1 1 - _.....ocoE 0.2 C...e o, 0iZa..- ,; : : so g . _I C ... '00-...I.-III Q)III Co.1~8oI I I ICUO


33/80

BASES FOR COMPARISONS OF PROCESSESFOR CLEAN FUELS

The electric power industry has diverse equipment andfuel requirements in spite of a common product. Geographiclocation in relation to raw fuel supplies and waste disposal,and retrofit, environmental and load factor considerationssuggest that beneficiation, fluidized bed combustion, coalgasification and coal liquefaction can all serve the utilityindustry. Research and development are therefore recommendedin each area.

In asses~ing the processes in each area, several factorswere considered. These include:

Present scale, scale-up and time to commercial operationComplexity, reliability, and safetyAdaptability to utility use'l'urn-downThermodynamic efficiencyEnvironmental considerationsE co no mi c e va lu at io nJudgementComparison to stack gas cleaning

Based on these factors, recommendations were made for supportin each area. The recommendations in each area are given inorder of priority in the "Evaluation of Various Routes toClean Fuels and Recommendations" section of this report.

15


34/80

16Scale-up and Time to Commercial Operation

An important consideration in choosing processes forfurther development is the time still needed to reach reliable,cornmercial operation. Developments usually proceed in theorder; bench scale (~100 Ibs/day), process equipment develop-ment unit (~1000 Ibs/day), pilot unit (25-75 tons/day), demon-stration plant (500-2000 tons/day), pioneer plant (first of akind at near commercial scale) and commercial scale plant(10,000-25,000 tons/day). With one to three years requiredfor each step, the time to reach commercial scale can belengthy. In some cases, it has been suggested that certaindevelopment steps be omitted. The larger scale-up require-ments are not nearly so risky when based on comparable process-ing steps in other industrial operations.

Table V summarizes the projected time schedule for themajor processes as obtained from research and developmentproposals, and interviews with project developers. The timeschedules are subject to the usual delays. Many of thoseprocesses with success in early or intermediate stages couldhave a pioneer or demonstration plant within five to ten years,given normal economic conditions.

It is clear from this study that few demonstration orpioneer scale units will be operating within five years undernormal procurement and the R&D conditions prevailing today.


35/80

17Complexity, Reliability and Safety

Evaluation of processes from the viewpoint of complexityis difficult since there are so many factors involved. IterrlSwhich add to the complexity are the number of processing steps,the operating pressure and temperature, the sensitivity tochanges in temperature, solids recirculation, moving partsat high temperature, corrosion, and the need for auxiliarypr oce ss pl an ts.

The complexity and the capital cost of a process isrelated to the number of processing steps or pieces of processequipment needed. When a process contains several pieces ofequipment which have a tendency to fail, the process reliabilitywould be of concern because of the probability for failure.

The TRW chemical beneficiation process, the molten saltprocesses and the COED pyrolysis process have several processsteps. Although many of the steps are related to currenttechnology, operations with coal or mineral matter in coaltend to complicate each step.

Reliability becomes more of a concern at high pressuresand temperatures especially if there are moving parts. Coaldissolution processes operate at fairly high pressures. Allneed pumps and pressure let-down systems and a few incorporatefiltration into the process. Although coal gasifiers do notneed to operate at particularly high pressures (usually lessthan 300 psi), lock hoppers would be required for pressuresin excess of 20-30 psig.


36/80

18The metal walls of reactor vessels must be protected from

high temperatures and corrosion. This is usually accomplishedby covering the inside surface with an insulating materialand a ceramic lining, or by cooling the walls with water. Allthe coal gasifiers use one method or the other.

The mineral matter in the coal puts temperature limits ongasification and pyrolysis. Gasifiers can operate below theash fusion temperature, near the fusion temperature as in ash-agglomerating gasifiers or above the slagging temperature.The ash-agglomerating gasifiers depend upon operating attemperatures where the ash is slightly tacky but not fluid.Such systems are sensitive to temperature variations and themineral content of the coal.

Recirculation and movement of solids is common to many ofthe gasifier and pyrolysis processes. Control of such move-ment adds to the complexit.y.

Auxiliary process plants are needed in many of t.heprocesses.The coal dissolution processes require hydrogen production.Many of the gasifier processes use oxygen although air canoften be used with a reduction in heating value of the product.Auxiliary equipment adds to the complexity of the total process.

Safety considerations are of great importance and appearto have been incorporated into all the processes. However,problems may be expected with high pressures and temperatures,gas leakage, flow and combustion instabilities, start-up andshut-down procedures, controls and instrumentation. Only long


37/80

19term, full scale plant operational experience will permit thesafety aspects to be fully known. Despite the best engineer-ing judgement in the design of new plants, a certain safetyrisk factor must be assessed to all untested processes. Thisrisk is in proportion to the pressure, temperature, reactionrates, and size of the project and inversely proportional tothe amount of actual operational experience of identical orvery similar processes.

In gasification the greatest hazard occurs when a coalor char supply to the gasifier is interrupted but the air oroxygen flow continues. This is most serious in an entrainedflow gasifier when the coal hold-up is'small and there ispo-tential for oxygen to mix with the synthesis gas. In theKoppers-Totzek gasifier the oxygen supply is automaticallyshut off when the coal supply is interrupted and eithernitrogen or steam used to purge the system. Similar safetyinterlocks would be required for all entrained flow gasifiers.

When looked at from the viewpoint of simplicity, reliabilityand safety, the fluidized bed boiler and the atmosphericpressure entrained flow gasifier appear to be the most suitablefor incorporation into electric utility power generation plants.

Adaptability to Utility Use

To a great measure, the success or acceptance of a newprocess depends upon the adaptability of the process to the

unique requirements of the particular utility plant, or theplant site to be served.


38/80

20

In retrofit applications, system derating is an importantconsideration. Boilers designed for gas and oil cannot beconverted to coal without substantial derating. IntermediateBtu synthesis gas from oxygen blown coal gasifiers and coalderived liquids can be used in these boilers with little orno derating although some changes in heat transfer surfacemay be required. The use of low Btu synthesis gas from airblown gasifiers will result in some derating of boilers designedfor oil and gas. Boiler modifications can minimize the extentof the derating.

The intended load application of the power operatingsystem influences the suitability and cost of coal conversionprocesses. Those which produce a fuel capable of beingstored economically have an inherent advantage for inter-mediate and peak shaving load applications and load following.In certain geographic locations underground storage of inter-mediate Btu gas makes coal gasification processes attractive.

The location, availability and characteristics of the coaland raw materials such as limestone become important in theselection of a coal conversion process. Certain coals can beused in certain processes and not at all in others. Wastedisposal must also be considered.

Control of a fuel generating system coupled to an electricpower generating system requires special attention. Hopefully,experience and understanding will result from the CommonwealthEdison - Lurgi program.


39/80

21Turn-down

The question of turn-down capacity of the various cleanfuel processes have been considered as a factor of importancein meeting the daily load variation of the electric utilityindustry. It is generally felt that such processes will bewidely used for intermediate load applications. All proces-ses which produce a clean, storable fuel are not tightlylinked to this daily load cycle and therefore can be run atdesign conditions under steady 24-hour per day operation.These include: chemical cleaning of coal, coal liquefactionand pyrolysis-based coal refineries. This becomes importantwhen considering the effective capital cost for a front-endclean fuel system used for intermediate or peak load applica-tions. For a 50% electrical load capacity factor the costof the clean fuel process with storage would be nearly one-half the cost of a plant for base load application.

There will be more problems associated with storingpyrolysis char than coal but it can be stored. Pyrolysischars tend to be dusty and pyrophoric. Only in certaingeographic locations will underground storage of low orintermediate Btu gas be economically and physically feasible.Intermediate Btu gas would be preferred.

Two considerations are important: capacity variation from100% to some lowest limit and start-stop-start capability.In general fixed-bed gasifiers such as the Lurgi and u . s . Bureauof Mines stirred-bed units are easiest to operate and operate


40/80

22well over a wide range. They can be kept in a banked condi-tion overnight with the natural draft aspiration of aircreating enough heat to maintain bed temperatures. Entrainedflow gasifiers can be operated at 50% of design rating inanalogous boiler technology. Start up of these units issomewhat complex, usually requiring gaseous or liquid fuelfiring and bypassing or venting initial gas production.Fluidized bed processes require gas flow for fluidization.They can be turned down to 50% or less capacity withoutproblems. As the load decreases, the bed porosity decreasesand approaches a fixed bed gasifier at low gas flow rates.

Most gasification processes require gas clean-up trainsfor H2S and particulate removal. These are based on con-ventional chemical processing technology and turn-down to50% should represent no special problem, providing considera-tion is given to this in the design stage. Start-up andshut down of these chemical processing trains will not be areasonable daily operating procedure. It would be preferableif such processes operated continuously, with maximum turn-down of 50%. Daily electric load variations must beaccomoda.ted by other means (pumped-storage, intermittentoperation of older plants, partial turn-down of base loadunits) rather than daily start-up and shut down of complexchemical processes.


41/80

23Thermodynamic Efficiency

The customary expression of efficiency used by the utilityindustry is the heat rate--that is, the energy input to thesystem as gross heating value of the fuel required to produceone kilowatt hour of electrical energy (Btu/kilowatt hour) .When comparing processes and raw materials or plants, it 1Svital that the total system be properly defined and allenergy demands be included. In comparing oil fired to coal-fired plants, the energy necessary to grind and inject coalmust be included as must oil pumping costs. In evaluatinggasification processes, the energy needed to supply air oroxygen, cooling water,stea~briquetting operations and soforth must be included in the accounting. Similarly, materialbalances must include all streams in and out.

In this study, it was frequently impossible to determineoverall thermal efficiencies of processes from reportsbecause of unreported data on inputs or output streams.Where enough information was available thermal efficienciesand/or heat rates were determined and included in Figure 1and in the process descriptions.

A refinement possible in the thermodynamic efficiency isthe use of the second law of thermodynamics to computeentropy production. This will be especially useful wherethere are multiple products from the process. Developmentof this type of analysis is a prospect for the future, anddetailed procedures are described in Part III.


42/80

24Environmental Considerations

The primary objective of coal conversion processes is toutilize coal in ways such that the emission of sulfur,nitrogen and hydrocarbon compounds and particulates areenvironmentally acceptable. This includes discharges ofgases, liquids and solids.

It is expected that many processes have the potential toreduce emissions well below EPA requirements. Where muchlower emissions can be realized at minimal additional costs,it is reasonable to expect that such additional costs bepaid.

The technology of hydrogen sulfide removal from gases at,somewhat above, and below ambient temperatures is wellestablished. Thermodynamic efficiencies would improve ifhigh temperature hydrogen sulfide removal systems could bedeveloped for commercial application. It would also beimportant that the nitrogen compounds such as ammonia beremoved since such compounds are commonly converted to theoxides of nitrogen upon subsequent combustion.

Gas liquors from gasification and liquefaction processesconstitute a water pollution problem. Treatment of suchwater waste streams will be required. Gasification processeswhich operate at high enough temperatures to crack oils andtars have a distinct advantage over other processes. Ammoniacould still be a problem.


43/80

25In coal liquefaction processes water will appear in the

light gas oil condensate. The water is from the originalcoal or from hydrogenation of ,the oxygen in the originalcoal. Water wastes must be treated prior to dischargeinto the environment.

Solid wastes become troublesome when they contain leach-able components in measurable amounts. This is especiallytrue when limestone is used and calcium oxide is formed orwhere the coal ash has unique qualities.

Front-end clean fuel processes will reduce the amountsof heavy metals discharged to the atmosphere because of gasclean~up.

E co no mi c E va lu at io n

In these days of uncertainties in cost of constructingplants, cost forecasting is no occupation for the timid.Economic evaluations were made based on the best informationavailable to the team. No claim for accuracy 1S made. Itis believed, however, that the relative costs are sufficientto give perspective to the various routes of coal utiliza-tion.

Since each of these processes uses raw energy with someinefficiency, it should be clear that the cost of the rawfuel itself becomes a factor in the operating cost.


44/80

26A write-up is included in Part III of the report which

discusses economics and the method of evaluating and compar-ing processes based on the Federal Power Commission procedure.The opportunity to carry out full economic comparisons wasnot possible because of the lack of hard information andsufficient time. Economic information reported is thatprovided to the study Team by process proponents rather thanb y ind ep end en t ca lc ula ti ons .

The general routes to the use of coal for electric powergeneration are shown in Figure 1. The costs in $/KW andthermal efficiences or energy penalties in Btu/KW-HR aregiven where estimates can be made at this time. The costscannot be considered firm because of the conditions underwhich the diverse economic studies were made. Studies havebeen made by proponents of the processes at an early stageof development. Studies have also been.made by independentengineering organizations with limited data in times ofmaterial shortages and inflation. The relative costs ofroutes are believed to be representative in comparing costdifferences between alternative routes.

Thermal efficiencies listed in Figure 1 are representa-tive of values capable of being realized at present.

As a basis for comparison q the overall investment costand the heat rate for a new conventional power plant aretaken as $340/KW and 9000 Btu/KW-HR respectively. Thisincludes the cost and energy penalty associated with parti-culates removal and ash handling. The additional cost and


45/80

27

energy penalty associated with stack gas clean-up are takenas $60/KW and 800 Btu/KW-HR. These values are consistentwith current information. Of the $340/KW, the overall invest-ment includes $165/KW for construction, site preparation,interest, contingencies, buildings, cooling towers andrelated items.

Based on the many cost values which have been presentedby various sources, the following is a list we believe validfor the processes in the order of increasing cost of newinstallations operated with coal to produce electricity forbase load:

conventional plant with tall stackFluidized bed combustionConventional boiler with stack gas cleaningCoal ga.sification with combined cycleChemical beneficiationCoal liquefaction with combined cycleCoal liquefaction with conventional plants

This is reflected in Figure 1 where costs are given in $/KW.As the application shifts from base to intermediate or peak-shaving load applications, the coal liquefaction and benefi-ciation processes which produce storable products tend tobecome competitive with the less expensive processes.


46/80

28The capital cost impact clearly depends upon application.

For intermediate or peaking load, a combined cycle plant withclean fuel derived from coal may be competitive with conven-tional plants because of the lower heat rates of the combinedcycle and the lower electric power generating costs. To takeadvantage of this aspect it is necessary to operate a smallfuel generating plant at or near maximum capacity and storethe extra fuel production for peak-shaving. Liquid fuelslook attractive for such applications. Low or intermediateBtu fuels could be attractive where inexpensive undergroundstorage could be made available.

The thermal efficiencies of the front-end clean fuel fromcoal processes range from 65-85%. As a consequence, theoverall heat rate from coal to electric power which incorporatesa front-end process will be in the range of 11,000-13,OQ OBtu/KW-HR. In periods of coal shortages and rising costs,energy conservation become extremely important. At heatrates of 9000-10,000 Btu/KW-HR, stack gas cleaning andfluidized combustion boilers look attractive.

Combined cycle plants with a somewhat higher efficiencythan a conventional system today, tend to off-set thepenalties associated with front-end clean-up. For a gasifierefficiency of 75%, the heat rate of the combined cycleportion of the plant would have to decrease from the presentvalue of some 8300 Btu/KW-HR to 7350 Btu/KW-HR before theoverall system heat rate could match plants with stack gas

clean-up. Potential improvements of this magnitude are notlikely in the next decade.


47/80

29Costs of several processes are available as preliminary

estimates for commercial plants. These specific costs areincluded in the sections on gasification, liquefaction,and chemical beneficiation and should be used knowing theircharacter.

On Figure 1, the $/KW are given as judgement values.

Judgement

After economic considerations, it is judgement or thecomposite assessment of all non-economic criteria which leadsto a final evaluation of a process. Judgement calls heavilyon experience when many of the criteria cannot be assessedfor lack of information or data.

Comparison to Stack Gas Cleaning

Processes for removing sulfur from coal before or duringcombustion could well be so costly and lack assurance ofbeing reliable for continuous operation that stack gas clean-ing in spite of its drawbacks and frustrations may well becheaper than and no worse operationally than producing cleanfuels from coal.

In this study, processes were evaluated keeping ln mindthat they would have to be potentially better than stack gascleaning processes to be considered as a viable alternative.

An evaluation of stack gas clean-up was not in the scopeof this study. However, a brief statement is included to


48/80

30give perspective to the alternate way of removing sulfur incoal--after combustion. The reader is referred to the reportby Falkenberry and Weir which presents the status of stackgas clean-up as the method of meeting emission standards andto the SOCTAP report sponsored by EPA.

From these studies one would conclude that the cost of newstack gas cleaning systems will range from $50-80/KW andretrofit installations will be considerably higher.

Statements could be included about the operational aspectsof stack gas cleaning processes, but the recipients of thisreport already have such information.

The energy penalty associated with stack gas cleaning rangesfrom 2-8% depending upon the process and reheat requirements.Front-end coal conversion processes are likely to have apenalty range from 15 to 35%.

When front-end sulfur removal processes are assessed withrespect to costs, costs are found to be high relative tostack gas cleaning. The stage of development and the timeneeded before front-end processes are available and reliable,indicates that stack gas cleaning may have relative merits.


49/80

GENERAL OBSERVATIONS

This study has exposed the Team to many related areasconcerned with energy and the environment and to manypeople of different viewpoints and opinions. Much of thisexposure was outside the immediate objectives of this studybut is of such importance as to warrant mention.

Institutional Restraints

The development and success of a process to provide cleanfuels from coal and the effort. required to attain commercialoperation depends upon factors outside technology as wellas in. The factors were called institutional restraints inthe Saxton River sessions on Energy Technologies for theFuture. Restraints can help and hinder development. Theelectric power industry through the Electric Power ResearchInstitute could well join others in concerted efforts tospeed up rational action in making coal available and convert-ing it to an acceptable fuel.

Common Interests with Gas and Oil Industries

The electric power industry has needs parallel to thenatural gas industry and the petroleum industry in providingfuels from coal. The research and development program sponsoredby the American Gas Association and the Office of Coal Researchto produce pipe-line quality gas from coal as a substitutenatural gas was recognized as a significant contribution to

31


50/80

32the electric power industry. Many of the coal gasificationprocesses could be used to produce low or intermediate Btugas where high heating values are unwarranted for utilityfuels. In other cases, new gasifier concepts were developedbased on research and development in the high Btu gas program.

The ultimate need to produce synthetic crude oil from coalhas been a concern of both government and petroleum companies.When the need arose for clean, low sulfur coal liquids forutility plants, work was already underway. Fuel oil desulfuri-zation research and experience in building and operatingdesulfurization processes in the petroleum industry lendsassistance to coal liquefaction process development.

It appears that the future plans for coal liquids go moreto coal refineries than to plants built specifically forutility plants and utility operation. Thus for steam genera-tion, use of the lower grade by-products of coal refineriesmay be best. Both avenues should be kept in mind. In anyevent, the impetus to produce crude oil is compatible withthe need for low sulfur utility fuels.

It is expected that the petroleum industry will developcoal refineries or coal pyrolysis processes with mUltiplesubprocesses and a series of products including low to highBtu gas, a series of fuel oils, and char. It is expectedthat certain products will be produced for combined cycleturbine fuels. Residual oils will be used as they are todayfor stearn generation. The utility may well be expected toaccept the burden of utilizing the char.


51/80

33Need for National Priorities and Allocations

As one looks to the time schedule for building the processdevelopment units, pilot, and demonstration plants and seesa decade of time consumed in the sequence, one questionstoday's pace as compared to those in the 1940's for thedevelopment of aviation gasoline, synthetic rubber, U-235 andother commodities. No doubt the desire of the public toachieve those goals was most important, but the use of engineer-ing judgement and willingness to take risks financed by thegovernment was another factor. A third factor which is nowseen in the energy crisis and is being felt today is priorityfor delivery of equipment and supply of services of skilledpeople.

EPRI might well join with other groups like the API, AGA,EJC, Labor Unions, and others in sponsoring methods to assurethe availability of steel, equipment, engineers, scientists,skilled trades, and enabling legislation for developing coalconversion processes as well as nuclear facilities.

pniversity and Institute Support

Manpower needs for coal conversion processes require in-creased enrollment and graduate study in several branchesof engineering and science. Graduate study can serve theutility industry in two ways: providing highly trainedtechnical personnel, and in developing technical knowledgeneeded.


52/80

34

The support of university work should be directed towardthe objectives of increasing the available pool of engineersand scientists who are competent and interested in the prob-

lems of the utility industry, and of increasing knowledgeand understanding of coal and coal processing. The nature ofuniversity research is that it is well-suited to the formula-tion of information and novel ideas which can improve the nextgeneration of processing and design, and in certain areas tothe solution of immediate problems.

Some subjects which are adaptable to the pace and scope ofuniversity work are:fundamental work on all properties ofcoal, mechanisms and kinetics of coal processing, studies inperipheral subjects such as disposal or recovery of wastematerials like calcium sulfate, underground storage of lowBtu gas for intermediate and peak-shaving loads, catalystdevelopment, process design and feasibility studies of newand novel ideas, meteorological studies of air quality impact,plant and wild-life problems associated with mining facilities.

Major non-profit research institutes have and will con-tinue to make important contributions, and also represent apool of experienced engineers and scientists. In general,their work seems to fall in the area between university-typeresearch and full-scale industrial work, but often overlapp-ing both. Support of work at such institutes and cooperationwith them should enhance the use of EPRI resources.


53/80

35Attention to Coal Mining

Increased usage of coals for utility boiler plants aswell as for providing replacements for natural gas andcrude oil will require substantial increases in coal mining.Automated mine development was recommended in the SaxtonRiver Conference to reduce the need for underground workmen.The adoption of higher standards for mine safety hasdecreased output per man-day for underground mines. Attentionto mining technology comparable to that required to put aman in space seems reasonable and advocacy of such supportby customers for coal, like the utility industry, seems justi-fied.

Another problem in public view is resistance to stripmining of coal, based in good part on past practices inwhich damage to the environment is evident today. Managementof acceptable methods of strip mining and education of thepublic on what can be done could remove a severe road blockto increased coal production by strip mining in the yearsahead.

Consideration of Tall Stacks

If acceptable commercial clean fuel from coal processesand reliable stack gas cleaning systems do not come intobeing in the short term, it may be necessary to resort totall stacks under certain conditions to protect our naturalgas and oil supplies. One way to operate on high sulfur


54/80

36coals with reduced environmental effects, is to use smokestacks which are 1000-1200 feet tall and rely on dispersion.This approach has been used in England and the ground levelair quality has been improved significantly over the pasttwo decades. Granted, this is not an ideal solution butwould provide time for a more rational development of coalconversion technology.


55/80

EVALUATION OF VARIOUS ROUTES TOCLEAN FUELS AND RECOMMENDATIONS

Fluidized Bed BoilersThe concept of fluidized bed combustion boilers has been

advanced recently by research in England, France and theUnited States. Fluidized beds which utilize limestone(atmospheric pressure) or dolomite (pressurized) providefor sulfur removal within the combustion chamber. Asdeveloped by Pope, Evans and Robbins and Foster Wheeler,the fluidized bed boiler has the merit of modular construc-tion and a high heat release rate and thus a reduced volumecombustion chamber. The possibility of economical steamgeneration at lower investment costs than by conventionalplants seems real.

The handling of the solid waste, containing sulfur asCaS04 has been studied by Esso and Argonne, both looking torecovering elemental sulfur and recycling the calcium toreduce raw material requirements. Regeneration processesfor a demonstration or commercial size plant are about adecade away.

Operation with limestone on a once-through basis createssolid waste problems. Even though CaS04 supposedly encapsu-lates the CaO , judgement would indicate that the solidwould be subject to dissolution by ground water in land fillareas. The Ca(OH)2 produced by hydration of unreacted CaO

37


56/80

38

has a solubility limit of 0.18% by weight in cold water andfresh CaS04 has a solubility of 0.2%. Carbon dioxide from theair would eventually convert the hydroxide to carbonate.Flue gas could be used to facilitate this conversion.Therefore, an air pollution problem has been converted toa potential water pollution problem. Accordingly therecommendations include research on handling the lime inthe waste as well as sulfur recovery as a priority item.The fluidized bed boiler has sufficient merit as a steamgenerator to warrant support even though solution to thechemical problems are in the early stages of development.

Recommendations for research and development support influidized bed combustion are:

The Fluidized Bed Boiler is recommended for supportbecause of the dual role it can play of giving economicalcompact units for steam generation at atmospheric or pressuri-zed conditions. It also can remove sulfur during thecombustion process by using limestone or dolomite as thefluidized bed.

A Process for Handling the Lime Waste should be developedfor a once-through process. Laboratory work, process develop-ment and environmental studies should be made to handle thedisposal of this waste until economical regeneration processesare developed.


57/80

39

Coal Beneficiation

The physical cleaning of coal involves crushing, grinding,sizing, solid separation, washing and flotation in various com-binations designed to reduce inorganic matter. A new processfor removing pyritic sulfur by stage-wise froth flotationwas recently announced. Recently, chemically induced breakage(comminution) using methanol and ammonia gained some interestthrough research conducted in Syracuse Research Laboratories.The coals which have been processed by physical beneficiationmust satisfy the usual pulverized boiler feed and environ-mental sulfur emission requirements.

As compared to physical treatment described above, chemicalbeneficiation goes a step further in that chemicals are usedto remove the pyritic sulfur from the coal. For coals withlow enough organic sulfur, this beneficiation is designed tomake those coals suitable for meeting environmental regula-tions. Chemical beneficiation is purported to remove up to90-95% of pyritic sulfur and lose not more than 5% of thecoal while current physical cleaning processes remove about50% of pyritic sulfur and to lose not more than 5% of theMeyers Process developed by TRW has had bench scale (5 liter)extraction tests with ferric sulfate [Fe2 (S04)3] as asolvent on four typical Appalachian coals. Based on bench-scale and pre-pilot test data, engineering design and costestimate studies have been under way for a process plantto treat 10,000 tons of coal per day.


58/80

40Disposal of solid and liquid wastes from this process

represents serious environmental problems. This aspect mustreceive at least as much attention as the disposal of CaOfrom fluidized bed combustion with limestone.

Recommendation for research and development support inbeneficiation is:

Support the TRW - Meyers $mall Scale pilot ~lant to convertsome high sulfur coals into coals which meet environmentalregulations for sulfur. If further data reinforce presentviews, demonstration plant support would be appropriate. Itis noted that the process uses processing steps based oncurrent technology and may be more predictable in scale-upthan processes with much new technology. Attention to wastestreams is essential.


59/80

41Pyrolysis

The pyrolysis processes reviewed were the COED, TOSCOALand Garrett flash pyrolysis processes. These processesyield low to high Btu gases, liquids and char. The gas canbe treated to remove sulfur and the oil hydrogenated tolower the sulfur content and the oil viscosity. Chars fromthe pyrolysis of high sulfur coal will contain too muchsulfur for burning in conventional boilers and must beutilized in fluidized boilers or as feed for gasification.

It appears that pyrolysis is more adapted to the conceptof a coal refinery than to a captive fuel plant for electricpower generation. A refinery could contain several coalpyrolysis units and the light desulfurized liquids or gaseswould be suitable for combined cycle operation. Also, someof the heavier oil fractions could become clean economicalboiler fuels. Char containing sulfur would be availablefor utility use but would have the same problems as highsulfur coa.ls.

It should be recognized that the COED process has consider-able operating experience at 36 tons/day and is a near atmos-pheric pressure process for clean gas and oil production.Advantages are claimed for char as feed to gasifiers. Itis non-caking, gives off no tars, and is claimed to have a


60/80

42high reactivity with oxygen and steam especially when hot.When these benefits and/or the desulfurization of charhas been demonstrated, the COED pyrolysis process has theability to produce fuels for gas turbines in the combinedcycle as well as boiler fuel with both the liquid and charin form for storage.

The TOSCOAL process is based on the oil shale retortingprocedures developed by the Shale Oil Corporation in theirTaSCa process. Coal has been retorted at a rate of 24 tons/day.In a demonstration unit, oil shale has been retorted at arate of 1000 tons/day and coal could be retorted.

It is recommended that when utility plants desire bothcombined cycle and boiler firing fuels, the pyrolysis processesmerit consideration. The gasification of char with desulfuri-zation of the fuel gas is the next step in the COED development,and should be given consideration because of the advanced stateof the pyrolysis technology.

Coal Gasification

Commercial low-to-intermediate Btu coal gasificationprocesses are currently available today through Lurgi andKoppers. They represent two diverse methods of gasificationbeing fixed-bed and slagging entrained-flow gasifiers, res-pectively. The Lurgi gasifier is limited to non-caking coalsat this time. The Winkler fluidized bed gasifier is also


61/80

43

available. It is limited to non-caking coals. To date therehas been no experience in coupling a gasifier system to aconventional power plant or a combined cycle plant. Controlexperience for such systems is needed. Capital cost of theavailable intermediate Btu gasifier systems is believed to beabout $170-$180/KW and the thermal efficiency is about 70%.

Coal gasification processes find their greatest opportuni-ties in conjunction with combined cycle plants. The higherthermodynamic efficiency of such combined plants tend tooffset the energy lost in gasification. It will be severalyears before the overall thermal efficiency matches that ofa conventional plant.

Developments through the pilot plant scale in this countryhave evolved from the Lurgi and Koppers-Totzek gasifiers.The work is directed toward the capital cost reduction andthe thermal efficiency improvements which are theoreticallypossible. It does not appear likely that commercial-sizeplants will be operating however before the 1980's based onthese developments.

Low and intermediate Btu gasification processes must belocated at or near the electric power plant because of theexpense in transporting lower Btu gases. It is expectedthat coal gasifiers will have to follow load. Storage costswould be excessive except perhaps where underground storageis available. From an economic standpoint, base-load


62/80

44operations would be preferred since the gasification plantcapacity must match the electric power generating capacity.

Coal gasification systems vary in complexity, start-upand shut down capability and turn-down. Unless the processis simple, reliable and amenable to control, it will bedifficult to couple to an electric power generation system.Turn-down of 50% for individual gasifiers seems likely formost systems. Environmental problems should be minimal.

The Combustion Engineering atmospheric two-stage slaggingentrained flow gasifier concept is reasonable, simple, offersminimum development problems and is directed toward reducingor eliminating the oxygen requirements of a Koppers-Totzekgasifier. Support for this program is therefore recommended.

Foster Wheeler has proposed a demonstration size plant.Although proven equipment is employed where possible, itrepresents a bold effort. The gasifier would be conceptuallysimilar to the Bi-Gas and Combustion Engineering gasifierand would operate at 500 psi.

The process analysis based on laboratory data shows thatmolten salt gasification and desulfurization has a possibi-lity of low cost and simple construction. Salt regenerationis based on known technology although the ash is a definitecomplication. The process is worth support through the nextstep of development to evaluate its feasibility.


63/80

45Recommendations for research and development support for

coal gasification are:The Combustion Engineering low pressure proposal should be

supported. We believe the entrained flow slagging gasifier,blown with air, has the potential to reach commercial scalein conjunction with combined cycle plants. The operationdraws upon the experience of reputable boiler manufacturers.It speaks to the critical development steps while eliminatingthe complexity of operating at high pressures in the earlydevelopment stage. The concept includes sub-processing stepswhich are available commercially.

H yd ro ge n p ro du ct io n by a Single Stage Slagging Gasifier forhydrogen production is needed. A process which is economicaland utilizes debris of liquefaction processes should be develop-ed for the coal dissolution processes. A hydrogen generationunit should be incorporated into a dissolution process, withcandidates recommended: Koppers-Totzek, Texaco or Shellg as if ie r p ro ce ss es .

The Foster Wheeler High Pressure Coal Gasification approachis comparable to that of Combustion Engineering except thatit is directed toward high pressure operation from the begin-ning. High pressure (100-300 psi) gasification is preferablefor combined cycle application. The Foster Wheeler approachis bold to the extent of size and pressure but if successfulcould cut out many years of development in reaching commercialscale and should be supported.


64/80

46

Molten Salt Gasification is a novel method of gasificationand deserves support. This process is attractive since itincorporates desulfurization with gasification and lends it-self to potential thermal efficiency improvements. Saltregeneration is complicated but based on establishedcommercial technology in the paper industry.

Coal Dissolution and Liquefaction

Coal liquefaction processes have been under developmentsince the late 1950's and have progressed through the processdevelopment unit size of 1-3 tons coal/day. The work drawsupon the technology of fuel oil desulfurization and exceptfor the coal solution and solids-separation steps lends it-self to the scale-up procedures practiced by the petroleumindustry. From our study we conclude that the HydrocarbonResearch, Inc. single step catalytic coal dissolution anddesulfurization (and denitrogenization) process offer~ thebest potential to reach commercial scale by 1980.

The capital cost estimates for commercial size coaldissolution plants directed to producing fuel oil for utilityuse range from $150-$435/KW and the thermal efficiencies forfuel production from 63--74%. The cost values cannot be con-sidered firm but indicate that the cost will be in excessof low Btu gas generation plants.

Liquid fuels offer a distinct advantage from a storagestandpoint. The fuel processing plant can be operated


65/80

47continuously at or near maximum capacity independent of theelectric power generating plant. The load-factor turn-downand load following problems associated with low Btu gasplants are nominally eliminated. All potential environmentalproblems can be handled.

Coal dissolution plants require several processing stepsand would be considered complex. Control and operationshould not be a problem because of the years of experiencein petroleum processing. It is natural to expect that theseplants will be operated by petroleum companies and the fuelssold for electric power generation.

As crude oil shortages persist, it is quite likely thatcoal liquefaction and coal pyrolysis plants will be builtfor gasoline, fuel oil and chemical feed stocks when scale-updata become available. Hea.vyresidual oils from such plantsshould fill utility plant needs as they do today.

Reco~~endations for research development support in coaldissolution and liquefaction are:

Catalytic Coal Liquefaction is worthy of support. Coalliquefaction plants will be operated and the fuel oil productssold to utility plants. Although there are a number ofprocesses being proposed for coal liquefaction, we believethat the H-coal process with ebullated bed reactor is mostadvanced and thus more likely to reach commercial scalequickly. It is an extension of the H-oil process and theknowledge of that process will facilitate scale-up. F1xed


66/80

48bed catalytic coal liquefaction has some inherent advantagesand should be encouraged.

The Southern Servis::esWil~onville Pilot Plant operationshould be continued and expanded. Support should be forth-coming to carryon such work as:

a) Evaluate congealed liquid productb) Modify system to operate on synthesis gas to evaluate

potential for liquid products (coordinate operations withTacoma plant to evaluat.e greater number of coals and operatingconditions)

c) Evaluate other solids - extract separation schemesand combinations of schemes

1) Hydroclones2) Totally submerged filter

A Slurry PumE Loop is needed. Processes which use coalslurries, including liquefaction, have a common need forequipment development. The successful continuous operationof the pumps serving the Black Mesa coal slurry pipelineshould be noted. Transfer of the technology to highertemperature coal slurry feed pumps should be almost direct.Pumping oi.Ls-coa L slurries cold and hot, pressure let-downsystems, and possible heat exchange with practical sizeequipment should be conducted with "live" slurries. There-fore, support is recommended for the development of hightemperature slurry pumps and pressure let down methods byequipment manufacturers.


67/80

49a) Build and operate a test loop to evaluate commercial

size pumps, pressure let down equipment and valves. Evaluateperformance, measure corrosion and erosion. This might bedone at Cresap, West Virginia.

b) Incorporate new developments into the loop for evalua-tion as t.heybecome available.

Insitu Combustion of Coal

The insitu combustion of coal could produce low Btu gaswhich could be desulfurized for utility power generation.Success to date, both physically and economically has beenof such low grade that one cannot foresee successful develop-ments near enough at hand to warrant any large scale projectsuntil the technology is more advanced. Small projects whichimprove the understanding of the process would seem reason-able. The use of fracturing and explosives to break up thecoal bed to permit fluid transmission and uniform combustionmay be worthwhile experiments to consider. Study of thenature of the flow channels in coal deposits, and of the gasretention qualities of caprocks both cold and hot are inter-mediate steps needed. Present work is supported by theBureau of Mines.


68/80

SELECTED BIBLIOGRAPHYCOAL CONVERSION PROCESSES

The following sources are selected for their availabilityand their coverage of the subject. First, there is a generallist of references describing the uses of coal as a cleanfuel. Then, references are broken down by subject.

G en er al R ef er en ce s

Office of Coal Research, Annual Reports, 1973, 1973, etc.Lowry, H.H., Chem~stry of Coal Utilization, Volumes I & II,John Wiley and Sons, New York, 1945.Lowry, H.H.; Chemistry of Coal Utilization Supplementary,Volume, Wiley and Sons, New York, 1963.National Academy of Engineering Report, "Evaluation of CoalGasification Technology, Part 1, Pipeline Q uality Gas,"COPAC-6, Washington, D.C., 1972.Hottel, H.C., and J.B. Howard, New Energy Technology, SomeFacts and Assessmepts, MIT Press; Cambridge, Mass., 1971.Bituminous Coal Research Inc., Gas Generator Research andDevelopment - Survey and Evaluation.Squires, A.M., "The Fossil Fuel Development Gap," paper atConference on Energy and the Environment sponsored by NSF,Las Crobas, Puerto Rico, February 22-24, 1972.Matthews, C.W., "Coal Gasification for Electric Power,"Proceedings of the American Power Conference, 1972, Vol. 34.Clean Fuels from Coal Symposium, Collected Papers, IGT,Chicago, Illinois, Sept. 10-14, 1973.American Gas Association, Fifth Annual Conference on PipelineQ uality Gas, Chicago, October 1973.Energy Technologies for the Future, Summary of Conference atSaxton River, Vermont, July 1972, Engineering Foundation, N.Y.

50


69/80

51Coal CleaningProgram for Processes for the Selective Chemical Extractionof Organic and Pyritic Sulfur from Fossil Fuels, ContractEHSD 71-7. Volumes I and II, J.W. Hamersma, E.P. Kontsonkos,M.L. Kraft, R.A. Meyers, G.J. Ogle, L.J. Van Nice, TRWSystems Group, 15 January, 1973.Froth Flotation Process, Wall Street Journal and New YorkTimes, December 1973.Chemical Comminution of Coal, Robert Aldrich, Life andMaterial Sciences Center, Syracuse University.

Liquefaction Processes - General

Consolidation Coal Company, "Summary Report on Project Gasoline",Office of Coal Research, Research and Development Report No.39, Volume 1.Kloepper, D.L., et al., "Solvent Processing of Coal to Producea De-Ashed Product"-,-Office of Coal Research and DevelopmentReport No.9, Contract No. 14-01-001-275 (August 22, 1962 -February 22, 1965).McIlvried, H.G., S.W. Chuon and D.C. Chronauer, "The GulfCatalytic Coal Liquids Process", Process Research Division,Report No. 6214RD015 May 25, 1973, Gulf Research and Develop-ment Co.Akhtar, Sayeed, et al., "Process for Hydrodesulfurization ofCoal in a Turbulent--:-Flow Fixed-Bed Reactor", 7lst NationalMeeting, AIChE, Dallas, Texas, February 20, 1972.Johnson, C.A., et al., "Product Status of the H-Coal Process,"Paper presented-at-rhe Clean Fuel from Coal Symposium, IGT,Chicago, Ill., Sept. 10-14,1973.

Gasification, General

Elliott, Martin A.,and Henry R. Linden, "Gas,Manufactured,"Chapter in Encyclopedia of Chemical Technology, Vol. 10,pages 353-442, 1966, Second Edition.Symposium on Coal Gasification etc., Chemical EngineeringProgress, 69, No.3, 31-66 (1973).Conn, A.L., "Low Btu Gas for Power Plants," CEP, ~, No. 12,56-61 (1973).


70/80

52

Evaluation of Coal Gasification Technology, Part I, Pipeline-Quality Gas, National Academy of Engineering, Washington, D.C.,1972.Westinghouse, Industry Team: Westinghouse Electric Corpora-tion, Public Service Indiana; Bechtel Corporation, AMAX CoalCompany, Advanced Coal Gasification System for Electric PowerGeneration, Proposal to Office of Coal Research, United StatesDepartment of the Interior, Washington, D.C., April 1972.

Gasification, Specific Process

Bi-gas:Glenn, R.A. and R.J. Grace, HAn Internally-fired Process Develop-ment Unit for Gasification of Coal Under Conditions SimulatingStage 2 of the BCR Two-Stage Super-Pressure Process," Am. GasAssoc., Synthetic Pipeline Gas Symposium, Pittsburg, Pa., 1968.Grace, R.J., "Development of the Bi-Gas Process", paper pre-sented at the "Clean Fuels from Coal" Symposiurn,Inst. Gas Tech.,Chicago, Ill., Sept. 10-14, 1973.

C.E. Atmospheric Pressure Gasifier:A Design Study of Atmospheric Pressure Coal Gasification forElectric Power Generation, J.J. Blaskowski and R.W. Koucky,Task II Report, Project 900120, Combustion Engineering Inc.,April 9, 1973.

Molten Salt Coal Gasifiers:Cover, A.E. and W.C. Schreiner and G.T. Skaperdas, KelloggCoal Gasification Process, CEP, March 1973.Cover, A.E., W.C. Schreiner and G.T. Skaperdas, "Kellogg'sCoal Gasification Process, il paper presented at IGT "CleanFuels from Coal" Symposium, Chicago, Ill., Sept. 11, 1973.Atomics International Division, Rockwell International Presenta-tion to EPRI, "Molten Salt Gasification of Coal for the Produc-tion of Low Btu Fuel Gas", AI-BD-73-20, Chicago, Ill., July 25,1973.


71/80

53Stirred Bed Gasifier;

Lewis, P.S., Liberatore, A.J., and McGee, J.P., StronglyCaking Coal Gasified in a Stirred-Bed Producer. BuMinesRept. of Inv. 7644, 1972, 11 pp.Foster Wheeler Pressurized Gasifier:

Coal Gasification Combined Cycle Pilot Plant, Phase I DraftReport for Office of Coal Research, Foster Wheeler Corpora-tion, August 9, 1973.

Koppers-Totzek:

Farnsworth, J.F., H.F. Leonard, D.M. Mitsak, and R. Wintrell, "Gasi-fication Production of Coal by the Koppers-Totzek Process," paperpresented at the "Clean Fuels from Coal Symposium," Inst. GasTech., Sept. 10-14, 1973.Dressler, R.G., et ale f "Operation of a Pow


72/80

54Agglomerating Ash Coal Gasifier:

Goldberger, W.M., "The Union Carbide Coal Gasification Process",Presented at Fourth Synthetic Pipeline Gas Symposium, Chicago,Oct. 30-31, 1972.Goldberger, W.M. I "Fly-Ash Emission and Erosion by Fly-Ashfrom a Self-Agglomerating Fluidized Bed Coal Burner", AlChEMeeting, Detroit, June 1973.Corder, W.C., and H.R. Batchelder and W.M. Goldberger, UnionCarbide/Battelle Coal Gasification PDV Design, Fifth SyntheticPipeline Gas Symposium, Chicago, October 1973.

Lurgi:

Elgin, D.C. and H.R. Perks, Trials of American Coals in LurgiPressure-Gasification Plant in Westfield, Scotland, FifthSynthetic Pipeline Gas Symposium, Chicago, October 1973.Rudolph, P.F., New Fossil Fuel Power Plant Process Based onLurgi Pressure Gasification of Coal, Lurgi Gesellschaft furWarne-und-Chemotechnik MBH, April, 1970.

Hygas:

Schora, F.C., B.S. Lee and J. Huebler, "The Hygas Process,"presented at the 12th World Gas Conference, Nice, 1973.Lee, B.S., "Status of Hygas Process - Operating Results,present.ed at the Fifth SyntheticPipeline Gas Symposium,Chicago, October 1973.CO2 Acceptor Process:Fink, Carl, liTheCO

2Acceptor Process," paper presented at the

"Clean Fuels from Coal" Symposium, lnst. Gas Tech., Chicago,Ill., Sept. 10-14, 1973.

Insitu Combustion of Coal

A Current Appraisal of Underground Coal Gasificatio~ ReportUSBM C-73671 (December 1971) by A.D. Little.


73/80

55Schrider, L.A. and J. Pasini, III,"Underground Gasificationof Coal,Pilot Test'~Hanna, Wyoming, October 1973. Paperat AGA Conference, O'Hare Inn.

Fluidized CombustionD.H. Archer, et al., Evaluation of the Fluidized Bed CombustionProcess. Westinghouse NTIS PB 211 494, Nov. 15, 1971.A.H. Bagnulo, et al., Development of Coal Fired Fluidized BedBoilers, Volume-I--(1970). Pope, Evans and Robbins for OCRContract 14-01-0001-478.J.W. Bishop, et al., Development of Coal Fired FluidizedBoilers. Pope, Evans and Robbins for OCR, Volume II, Supt.Doc. 2414 0048, February 1972.H.R. Vogel, et al., Reduction of Atmospheric Pollution byApplication of Fluidized Bed Combustion? Argonne NationalLaboratory ANL/ES-CEN 1005, EPA R-2-73-253 (1972).H.R. HOy and A.G. Roberts, Fluidized Combustion of Coal atHigh Pressures, AIChE Symposium Series, Vol. 68, No. 126 (1972).Esso Engr. EPA Studies. NTIS PB 210-246, Dec. 3, 1971~Shopp, A. et al., Studies of the Fluidized Lime-Bed CoalCombustion Desulfurization System. Report Control SystemsDivision, Office of Air Programs, Environmental ProtectionAgency, Dec. 31, 1971.Hammons, G. and A. Shopp, A Regenerative Limestone Processfor Fluidized Bed Coal Combustion and Desulfurization, Preparedfor Process Control Engineering Program, Air Pollution ControlOffice, EPA. Feb. 28, 1971."The Scale-up of a Fluidized-Bed Combustion System UtilityBoilers", Godel, Albert and Paul Cosan, CEP Symposium Series67, No. 116, 210 (1971)."Air Pollution Control Through New Combustion Process",Ehrlich, Shelton, Combustion, August 1971, p. 36."ER&E Sets Pilot Plants to Burn High Sulfur Coal with Low S02Discharge," Oil and Gas J, Nov. 20, 1972, p. 83.


74/80

56"Fluidized Combustion of Coal at High Pressures," Hay, H.R.and A.G. Roberts, CEP Symposium Series ~~, No. 126, 225 (1972).

Pyrolysis and Base Coal RefineryCOED:

A.H. Strom and R.I. Eddinger, COED Plant for Coal Conversion,Chern.Eng. Prog., Vol. 67, No.3, p. 75 (1971).J.F. Jones, Project COED, IGT Symposium, Sept. 10-14, 1973.J.F. Jones, et al., Char Oil Energy Development, FMC Corpora-tion to OCR,~&O-Report No. 73, July '7l-June '72.

Toscoal:Carlson, F.B., L.H. Yardumian and M.T. Atwood, "The ToscoalProcess for Low Temperature Pyrolysis of Coal", Chern.Eng.Prog. 68, No.3, 50 (1973).Atwood, M.T., Toscoal Process, Presented at the Clean Fuelsfrom Coal Symposium, IGT, Chicago, Ill., Sept. 10-14, 1973.

Garrett:

Adam, D.E., S. Sach and A. Sass, "The Garrett PyrolysisProcess", paper presented at 66th Annual Meeting AIChE,Philadelphia, Pa., Nov. 15, 1973.McMath, R.E. Lumpkin, and A. Sass, "Production of Gas fromWestern Sub-bituminous Coals by the Garrett Flash PyrolysisProcess", paper presented at 66th Annual AIChE Meeting,Philadelphia, Pa., Nov. 15, 1973.

Stack Gas CleaningFalkenberry, H.L. and Alex Weir, Jr., Status Report andRecommendations on Control of Gaseous Emissions to TaskForce on Utilization of Coal of EPRI (1973).


75/80

57Final Report Sulfur Oxide Control Technology AssessmentPanel (SOCTAP) on Projected Utilizat

evaluation coal conversion process

Documents