Pressurized Fluidized Bed Combustion

Pressurized Fluidized Bed Combustion

Edited by

M. Alvarez Cuenca Professor

Department of Chemical Engineering Ryerson Polytechnic University

Toronto

and

E. 1. Anthony Research Scientist

CANMET Natural Resources Canada

Ottawa

Imi SPRlNGER-SCIENCE+BUSINESS :MEDIA, B. V.

First edition 1995

© 1995 Springer Science+Business Media Dordrecht OrigiDally published by Chapman & Hali in 1995 Softcoverreprint ofthe hardcover 1st edition 1995 Typeset in 10/12pt Times by AFS Image Setters Ltd, Glasgow

ISBN 978-94-010-4271-0 ISBN 978-94-011-0617-7 (eBook) DOI 10.1007/978-94-011-0617-7 Apart from any fair dealing for the purposes of research or private study, or criticism or review, as permitted under the UK Copyright Designs and Patents Act, 1988, this publication may not be reproduced, stored, or transmitted, in any form or by any means, without the prior permission in writing of the publishers, or in the case of reprographic reproduction only in accordance with the terms of the licences issued by the Copyright Licensing Agency in the UK, or in accordance with the terms oflicences issued by the appropriate Reproduction Rights Organization outside the UK. Enquiries concerning reproduction outside the terms stated here should be sent to the publishers at the Glasgow address printed on this page.

The publisher makes no representation, express or implied, with regard to the accuracy of the information contained in this book and cannot accept any legal responsibility or liability for any errors or omissions that may be made.

A catalogue record for this book is available from the British Library

Library of Congress Catalog Card Number: 95-79036

@Printed on acid-free text paper, manufactured in accordance with ANSIjNISO Z39.48-1992 (Permanence of Paper)

Preface

Pressurized fluidized bed combustion (PFBC) has recently entered the commercial arena. However, despite the enormous efforts and resources spent to bring the technology to this juncture, there is no primary text available for the professional engineer or researcher. The operation of fluid beds at high pressures increases the complexity of the process and largely invalidates much of the experience gained with atmospheric fluid beds. In that regard, the Grimethorpe Project (1980-1984), sponsored by the Governments of Germany, USA and UK under the auspices of the International Energy Agency, constitutes the origin of PFBC technology.

This text therefore represents an important first, and with this in mind, the editors have pursued two major objectives. The first was to provide as complete an account of the technology as possible, and the second was to ensure that the criteria of objectivity and excellence were met. Both objectives have been sought by the same means, by inviting all the major players in the field of PFBC to be part of this collaboration. Ultimately, it is the reader who must judge how well we have succeeded, but we the editors believe that it would be difficult to find a more appropriate and distinguished list of contributors, most of whom are currently involved in the state-of-the-art development of this technology.

The beginnings of PFBC can be traced back as far as the 1920s with Winkler's coal gasifier and the 1940s, with the introduction of the first commercial fluid catalytic cracking plant by Standard Oil Development Company (now Exxon) and the complementary work done at the Massachusetts Institute of Technology. However, the evolution of PFBC is much more recent, and the reader is referred to the introductory chapter in this book for an account of this development.

The commercialization of PFBC has followed a similar path to that of catalytic cracking. Equally, its development is not simply the result of overcoming technological problems, since there are many well developed technologies which never achieve commercial maturity. Rather, its fruition

vi PREFACE

is due to a synthesis of social pressures for a cleaner environment, the realization that coal is a fuel with excellent prospects well into the 21st century, and entrepreneurial confidence in this technology.

A glance at some of the market studies done in the early 1980s on the expected demand for PFBC in the mid-1990s should warn us against economic predictions, especially as regulatory forces often operate as a model breaker. However, there seems little doubt that the establishment offull-scale demonstration plants in Japan, Spain, Sweden and the USA herald the commercial phase of the technology.

As far as possible, this book is ordered in a logical fashion. The introduction, which gives a historical overview of PFBC, is followed by two chapters on the hydrodynamics and combustion processes relevant to PFBC. This is then followed by a discussion of the plant layout and the various sub-systems that characterize a PFBC boiler. These include the technologies for feeding solids into a high pressure and temperature reactor, the combustor itself, the methods for hot gas clean-up that are vital to the success of pressurized fluidized bed boilers and, of course, the subject of emissions, both solids and gaseous. Subsequent chapters deal with essential ancillary topics such as the combined cycle itself, an overview of the energy and exergy aspects of PFBC, and process control. Concluding chapters provide a review of the engineering challenges for the technology, the economics of PFBC and, finally, a worldwide overview of PFBC pilot and demonstration plants.

Although the bulk of this book has been written by engineers and scientists from a variety of disciplines, this text should also be useful to regulators and policy makers. This is especially so because PFBC is one of the few commercial technologies for power generation on a utility scale with low emissions of pollutants and the ability to minimize CO2 emissions via high efficiency electrical energy cycles.

Acknowledgments

First and foremost we wish to express our posthumous recognition to Randall Dellefield of the USA Department of Energy to whom the book is dedicated. His premature death has deprived PFBC of one of its exceptional workers.

Many individuals have made this book possible. Our thanks are due to the authors who took time away from any other pressing tasks to prepare their respective chapters. We also owe a vote of thanks to Roland Clift, at the University of Surrey, who provided the instigation for writing this book during a visit to Escatron. Our gratitude goes to John W. Easton of Ryerson Polytechnic University for facilitating our task without reservations. In addition, we wish to thank Raymond Hoy and his coworkers whose reward for completing their introductory chapter two years in advance of most others, was to have to revise it substantially in 1995. We also wish to thank

PREFACE vii

John B. Grace, of the University of British Columbia, for reviewing the chapter on fundamentals, Robert Reuther of the US Department of Energy, for reviewing and revising chapter 13 and also John Wheeldon of the Electric Power Research Institute for providing an addendum to up-date the chapter following the untimely death of Randall Dellefield.

Finally, the editors must thank the staff at Blackie Academic and Professional for their unfailing patience and encouragement to get this project completed. We should also acknowledge the patience of our wives, Jirina Cuenca and Louise Green, who had to live with this project, willing or not. Last and not least, we would like to acknowledge Heather Whitebread at CANMET, who was the typist during the production of this book and whose tireless efforts in typing, and retyping various chapters and careful formatting and proofing contributed significantly to its successful completion.

Dedication

Randall John Dellefield 1957-1994

M.A.C E.J.A.

This volume is dedicated to the memory of Randall John Dellefield. Randy was born September 3, 1957, in Hertfordshire, England. He was a 1975 graduate from Canton (Ohio) High School, a 1980 graduate of the University of Cincinnati with a bachelor of science degree in chemical engineering, and a 1986 graduate of the University of Pittsburgh with a master's degree in business administration. Randy worked for the United States Department of Energy at the Morgantown Energy Technology Center in Morgantown, West Virginia, where he held the position of Pressurized Fluidized Bed Combustion Production Manager at his death. In this role, he was responsible for championing the development and commercialization of fluidized bed combustion. However, this was not a self-serving advocacy. He believed it was the best technology to meet future power generation needs. He worked tirelessly and frequently behind the scenes to resolve technical issues in fluid beds, especially with respect to high temperature filters. His work (for example on the Steering Committee of the International Fluidized Bed Conferences), in bringing the R&D community, technology suppliers, and technology users together was outstanding and will be sorely missed. It was primarily through his work as the PFBC Topic Coordinator at the 11th Conference and his role as the Program Coordinator for the 12th Conference that these conferences were successful. At the time of his death he was actively at work on the Steering Committee to make the 13th Conference an equal or even greater success.

viii PREFACE

Through his work, Randy gained a reputation as a quintessential advocate for fluidized bed combustion. His friendly personality, his understated but professional manner and his diligent work ethic were all essential and successful in helping to bring fluidized bed combustion to its current position, with atmospheric fluidized bed combustors a commercial reality and pressurized units of several different designs in demonstration and on the verge of commercialization.

Randy authored or co-authored more than a dozen technical articles on fluidized bed combustion in his short lifetime. One of his last contributions was chapter 13 in this volume. Randy was killed in an airplane crash in Pittsburgh, PA, on September 8,1994, while returning from the annual Clean Coal Conference in Chicago, Illinois, where he was continuing to champion fluidized bed combustion. He is survived by his wife, Cynthia Cline, and a son, Kyle.

We shall all miss him. Rest in peace, Randy.

Contributors

E.J. Anthony

P.E. Botros

A.S. Carmona

e.E. Carr

P. Colclough

M. Alvarez Cuenca

R.J. Dellefield

e. Dopazo

N. Fueyo

J.e. Garcia

S.J. Goidich

D.A. Horazak

CANMET, Natural Resources Canada, 555 Booth Street, Ottawa, Canada KIA OGI

Department of Energy, Morgantown Energy Technology Center, PO Box 880, Collins Ferry Road, Morgantown, WV 26507-0880, USA

Empresa Nacional de Electricidad, Madrid, Spain

Coal Technology Development Division of British Coal Corporation, PO Box 199, Stoke Orchard, Cheltenham, Gloucestershire GL52 4ZG, UK

Consultants in Environmental Sciences Ltd, 5 Tabley Court, Victoria Street, Altrincham, WA14 1EZ, UK

Department of Applied Chemical and Biological Sciences, School of Chemical Engineering, Ryerson Polytechnic University, 350 Victoria Street, Toronto, Ontario, Canada M5B 2K3

Department of Energy, Morgantown Energy Technology Center, PO Box 880, Collins Ferry Road, Morgantown, WV 26507-0880, USA

Centro Politecnico Superior, Universidad de Zaragoza, Spain

Laboratorio de Investigacion en Technologias de la Combustion, 50015 Zaragoza, Spain

Empresa Nacional de Electricidad, Madrid, Spain

Proposal Engineering, Fluidized Bed Systems Department, Foster Wheeler Energy Corporation, 12 Peach Tree Hill Road, Livingston, NJ 07039, USA

Gilbert/Commonwealth, Inc., 2675 Morgantown Road, Reading, PA 19607, USA

x

H.R. Hoy

T.E. Lippert

S.A. Miller

M.J. Mudd

R.A. Newby

R.D. Pitt

W.F. Podolski

F. Preto

A.G. Roberts

A. Robertson

M.A. Rosen

R. Shoemaker

J.E. Stantan

W.M. Swift

R.V. Wardell

J.M. Wheeldon

CONTRIBUTORS

Hoy Associates Ltd, 10 Forlaze Road, Wadebridge, Cornwall PL27 6LL, UK

Westinghouse Science & Technology Center, 1310 Beulah Road, Pittsburgh, PA 15235-5098, USA

Argonne National Laboratory, Chemical Technology Division, 9700 South Cass A venue, Argonne, IL 60439-4837, USA

American Electric Power, 1 Riverside Plaza, Columbus, OH 43215, USA

Westinghouse Science & Technology Center, 1310 Beulah Road, Pittsburgh, PA 15235-5098, USA

Department of Mechanical Engineering, Fachhochschule Schmalkalden, Blechhammer 4u.9, PO Box 182, D-98564 Schmalkalden/Thur., Germany

Argonne National Laboratory, Chemical Technology Division, 9700 South Cass A venue, Argonne, IL 60439-4837, USA

CANMET, Natural Resources Canada, 555 Booth Street, Ottawa, Canada KIA OGI

'Old Forge', Fore Street, Hartland, Bideford, Devon EX3 6BD, UK

Applied Thermodynamics Department, Foster Wheeler Development Corporation, 12 Peach Tree Hill Road, Livingston, NJ 07039, USA

Department of Mechanical Engineering, Ryerson Poly­technic University, 350 Victoria Street, Toronto, Ontario, Canada M5B 2K3

American Electric Power, 1 Riverside Plaza, Columbus, Ohio 43215, USA

10 Birch Tree Way, Croydon, Surrey CRO 7JY, UK.

Argonne National Laboratory, Chemical Technology Division, 9700 South Cass A venue, Argonne, IL 60439-4837, USA

Yew Tree Villa, Wickridge Street, Ashleworth, Gloucester GL19 4JW, UK

Electric Power Research Institute, 3412 Hillview A venue, Palo Alto, CA 94304, USA

Contents

1 Introduction 1

H.R. HOY, A.G. ROBERTS and J.E. STANTAN

1.1 The history 1 1.1.1 The early stages 2 1.1.2 Establishment of the technology 6 1.1.3 Towards commercialization of PFBC 16 1.1.4 Demonstration and commercialization 17

1.2 The future 20 1.2.1 In the UK 21 1.2.2 In the USA 23

1.3 In conclusion 23 Acknowledgements 24 Appendix: Chronology of events in the development of PFBC 24 References 30

2 Fluidization fundamentals 38 N. FUEYO and C. DOPAZO

2.1 Introduction 38 2.1.1 Fluidization 38 2.1.2 Chapter layout 39

2.2 Particle dynamics 40 2.2.1 Particle geometric characterization 41 2.2.2 Particle drag 42 2.2.3 Particle terminal velocity 43 2.2.4 Particle fluidization characteristics 46

2.3 Bubble dynamics 47 2.3.1 Jet penetration and bubble formation 47 2.3.2 Bubble shape 49 2.3.3 Bubble rising velocity 49 2.3.4 Flow-field in and around the bubble 50 2.3.5 Bubble size 53 2.3.6 Bubble stability (maximum bubble size) 53

2.4 Bed dynamics 54 2.4.1 Pressure drop 54 2.4.2 Bed voidage 56 2.4.3 The minimum fluidizing velocity, urn! 57

Xll CONTENTS

2.4.4 Minimum bubbling velocity 2.4.5 Two-phase theory 2.4.6 Entrainment, transport disengaging height and elutriation

2.5 Dynamic similarity 2.5.1 Basic dimensionless parameters 2.5.2 Scaling laws

2.6 Pressure effects 2.6.1 Effect on minimum fluidizing velocity, umf

2.6.2 Effect on bed voidage 2.6.3 Effect on bubbling characteristics 2.6.4 Effect on entrainment and elutriation 2.6.5 Some dynamic scaling considerations

2.7 Heat transfer concepts 2.7.1 Phenomenology 2.7.2 Thermal dimensionless groups 2.7.3 Dense-phase heat transfer 2.7.4 Gas-phase heat transfer 2.7.5 Heat transfer scaling rules

2.8 Some closing remarks 2.9 Nomenclature

2.9.1 Latin 2.9.2 Greek 2.9.3 Subscripts/superscripts

References

3 Pressurized combustion in FBC systems E.l. ANTHONY and F. PRETO

3.1 Introduction 3.2 Fundamentals of coal combustion in FBC systems

3.2.1 Combustion of coal particles 3.3 Carbon conversion processes

3.3.1 Combustion efficiency 3.3.2 Carbon monoxide 3.3.3 Interactions between S02 and CO

3.4 Nitrogen oxide emissions 3.4.1 NOx emissions 3.4.2 The effect of limestone on NOx

3.4.3 N20 emissions 3.4.4 The combined emissions of NO, and N 20 3.4.5 N 20 emissions control strategies

3.5 Sulfur capture in FBC 3.5.1 The sulfation mechanism 3.5.2 Sulfation capacity of limestones 3.5.3 Sulfation at pressure 3.5.4 The dependence of sulfur capture on temperature 3.5.5 S03 formation

3.6 Conclusions Acknowledgements References

4 General configuration of a PFBC plant M.l. MUDD

4.1 PFBC cycles 4.1.1 Advanced cycle

58 59 60 63 64 65 66 66 67 68 68 69 69 70 70 71 72 72 73 74 74 76 76 77

80

80 80 81 85 85 86 89 90 94 95 96 98 99

101 101 102 106 109 111 113 113 114

121

121 124

CONTENTS xiii

4.2 Major components in an FBC plant 126 4.2.1 Combustor 126 4.2.2 Gas turbine 126 4.2.3 Gas cleaning system 126 4.2.4 Steam cycle 128 4.2.5 Solids handling system 128 4.2.6 Economizer 129

4.3 Layout considerations 130

5 Solids preparation and handling 135

R.V. WARDELL

5.1 Introduction 135 5.2 Lock-hopper feed systems 135

5.2.1 Coal preparation 135 5.2.2 Silo storage practice 138 5.2.3 The lock-hopper feeder 138 5.2.4 Fuel feed rate control 142 5.2.5 Rotary valves 144 5.2.6 Instrumentation 146 5.2.7 Conveying air and inert gas supply 147

5.3 Coal-water mixture feed systems 148 5.3.1 Slurries and pastes 148 5.3.2 Slurry preparation 149 5.3.3 Slurry pumping 150 5.3.4 Slurry handling 152 5.3.5 Paste preparation 153 5.3.6 Paste pumping and handling 153

5.4 Fuel injection into the combustor 155 5.4.1 Injection considerations 155 5.4.2 External isolation 157 5.4.3 Expansion and vibration 157 5.4.4 Thick paste feeding 157

5.5 Other feed systems 158 5.5.1 The Stamet Corporation's firth pump 158 5.5.2 The Lockheed kinetic extruder 159 5.5.3 ERDA coal demonstration plants 160

5.6 Sorbent preparation and feeding 161 5.7 Comparative availabilities 162

5.7.1 Lock-hopper feeders 162 5.7.2 Slurry system availabilities 162

5.8 Summary 162 References 163

6 The pressurized combustor 164 S.l. GOIDICH and A. ROBERTSON

6.1 Process configurations 164 6.1.1 Fluidization mode 164 6.1.2 Steam cycle considerations 164

6.2 Bubbling fluidization bed steam generator 166 6.2.1 Boiler manufacturing techniques 166 6.2.2 First US electric utility fluidized bed boiler 167 6.2.3 Improvements 171 6.2.4 PFB combustion cell shape 173

xiv

6.2.5 Steam/water circuitry 6.2.6 Tube bundle design 6.2.7 Pressure vessel design 6.2.8 Maintenance

CONTENTS

6.3 Circulating fluidized bed steam generator 6.3.1 Combustor 6.3.2 Cyclones 6.3.3 Sealing device 6.3.4 Fluidized bed heat exchanger 6.3.5 Technology trends

6.4 Auxiliary systems 6.4.1 Feeding 6.4.2 Draining 6.4.3 Preheating

References

174 176 177 181 182 184 187 190 192 198 201 201 206 208 209

7 High-temperature particulate control T.E. LIPPERT and R.A. NEWBY

211

7.1 Introduction 7.2 HTPC specifications

7.2.1 Operating conditions 7.2.2 Fly-ash properties 7.2.3 Performance requirements 7.2.4 Design requirements

7.3 HTPC concepts 7.3.1 HTPC concept classification 7.3.2 Description of HTPC concepts

7.4 Rigid barrier filter system designs 7.4.1 System and vessel components 7.4.2 Filter element types and characteristics 7.4.3 Filter element arrangements 7.4.4 Filter design procedures

7.5 Rigid barrier filter performance 7.5.1 Development evolution 7.5.2 Test experience overview 7.5.3 Filter dynamics 7.5.4 Filter cake properties 7.5.5 Filter element durability

7.6 Conclusions References

8 Air emissions from pressurized fluidized bed combustors W.F. PODOLSKI, W.M. SWIFT and S.A. MILLER

211 212 212 213 214 215 216 216 216 226 226 228 233 235 237 237 239 242 249 251 253 254

257

8.1 Introduction 257 8.1.1 Emissions standards 258

8.2 Emissions of sulfur oxides 261 8.2.1 The reaction of sulfur dioxide with limestone and dolomites 262 8.2.2 PFBC operating results 267 8.2.3 S03 emissions 275 8.2.4 Advanced FBC concepts 277

8.3 Emissions of nitrogen oxides 279 8.3.1 Formation mechanisms 280

CONTENTS

8.3.2 Fluidized bed combustion experience 8.3.3 Reduction of nitrogen oxides 8.3.4 Summary

8.4 Particulate emissions 8.5 Other emissions

8.5.1 Carbon monoxide 8.5.2 Alkali metals 8.5.3 Hazardous air pollutants 8.5.4 Carbon dioxide

References

9 The disposal and utilization of ash residues from

xv

282 288 290 290 297 297 298 300 309 311

PFBC ns C.E. CARR and P. COLCLOUGH

9.1 Introduction 9.2 PFBC ashes examined in study 9.3 PFBC ash characteristics

9.3.1 Chemical composition of PFBC ash 9.3.2 Mineralogy of PFBC ash 9.3.3 Physical properties of PFBC ash 9.3.4 Fibrogenic and mutagenic properties of PFBC ash

9.4 PFBC ash handling 9.4.1 Ash conditioning 9.4.2 Self-hardening properties

9.5 PFBC ash leaching behaviour 9.5.1 Shake leaching studies 9.5.2 Column leaching studies 9.5.3 Discussion

9.6 PFBC ash utilization 9.6.1 Structural fill 9.6.2 Road base material 9.6.3 Aggregate in asphalt 9.6.4 Autoclaved bricks and blocks 9.6.5 Agricultural applications

9.7 Conclusions References

10 The combined cycle R.U. PITT

318 318 320 320 324 325 327 329 330 330 333 335 340 346 348 349 350 353 357 360 362 363

366

10.1 Introduction 366 10.2 Basic combined cycle concepts 369

10.2.1 Steam and gas (STAG) combined cycle with unfired waste heat boiler 369

10.2.2 Combined cycle with fired waste heat boiler 371 10.2.3 Compound cycle 371 10.2.4 Combined cycle with diabatic pressurized combustion 372

10.3 Pressurized fluidized bed internal combustion combined cycles 375 10.3.1 Scope of discussion 375 10.3.2 Concepts 376

10.4 Gas turbine integration into PFBC combined cycles 389 10.4.1 Introductory comments 389 10.4.2 Tasks to be solved 392

10.5 Conclusions 414 References 417

xvi CONTENTS

11 Energy and exergy analyses of PFBC power plants 419 M.A. ROSEN and D.A. HORAZAK

11.1 Introduction 419 11.2 Energy and exergy analyses 419

11.2.1 Rationale for energy and exergy analyses 420 11.2.2 Nomenclature and terminology 421 11.2.3 Balance equations and basic quantities 421 11.2.4 The reference environment 426 11.2.5 Efficiencies 427 11.2.6 Properties for energy and exergy analyses 428 11.2.7 Steps for complete thermodynamic analysis 429

11.3 Illustrative example 430 11.3.1 Description of the PFBC power plant considered 430 11.3.2 Approach and methodology 432 11.3.3 Results and discussion 432 11.3.4 Conclusions for illustrative example 439

11.4 Summary 440 Nomenclature 440 Appendix: Sample calculation 441 References 445

12 Process control 449 R. SHOEMAKER

12.1 Process control function and philosophy 449 12.2 Overview 449 12.3 Process control and measurement equipment 449

12.3.1 Inputs/outputs 453 12.4 Process control, protection and monitoring systems 454

12.4.1 Process control loops 454 12.4.2 Critical control loops 456 12.4.3 Unit integrated control system 456 12.4.4 Protection systems 460 12.4.5 Alarms and monitoring systems 462 12.4.6 Operator interface 463

12.5 Unit operation and automatic control 467 12.5.1 Unit start-up 467 12.5.2 Normal load range 470 12.5.3 Combustor trip 471 12.5.4 Steam turbine trip 472 12.5.5 Gas turbine trip 472 12.5.6 Loss of feed water trip 475

12.6 Summary 474

13 The demonstration units: Escatron and Tidd, four years of operation 475 M. ALVAREZ CUENCA, A. SALDANA CARMONA

and J. CALVO GARCIA

13.1 Introduction 475 13.2 PFBC in Spain: The selection of PFBC 475 13.3 The Escatr6n project 477

CONTENTS xvii

13.4 Plant description 479 13.4.1 Coal and sorbent preparation 480 13.4.2 Fuel feeding system 482 13.4.3 The pressure vessel and internals: The combustor,

the gas cleaning system and the load variation system 483 13.4.4 Gas turbine and compressor assembly 484 13.4.5 The steam turbine 485 13.4.6 Ash extraction and cooling 485 13.4.7 Control system 485 13.4.8 The air-gas cycle 486

13.5 Operational experience in Escatron (1990-1994) 489 13.5.1 Year 1991 489 13.5.2 Year 1992 492 13.5.3 Year 1993 492 13.5.4 Year 1994 494

13.6 Overall performance of the unit 494 13.6.1 Coal dust explosions in the feeding system 494 13.6.2 Ash deposits 495 13.6.3 The steam cycle 495 13.6.4 The gas cycle 496 13.6.5 The cyclones 496 13.6.6 The gas turbine 496 13.6.7 Fuel preparation and injection 497 13.6.8 Bed ash extraction 497

13.7 Final remarks 497 13.8 PFBC in the USA: Selection of the technology 498 13.9 The Tidd project 501 13.10 Plant description 502

13.10.1 Coal preparation and injection 503 13.10.2 Sorbent preparation and injection 504 13.10.3 Pressure vessel and internals: The combustor, the gas cleaning

system and the load variation system 504 13.10.4 Control system 504 13.10.5 Gas turbine and compressor assembly 505 13.10.6 The steam cycle 505

13.11 Operational experience in Tidd (1990-1994) 505 13.11.1 Year 1991 507 13.11.2 Year 1992 507 13.11.3 Year 1993 509 13.11.4 Year 1994 510

13.12 Overall performance of the unit 510 13.12.1 Post-bed combustion 512 13.12.2 Sinter formation 512

13.13 Final remarks 513 Acknowledgement 514 References 514

14 Economics of PFBC technology RJ. DELLEFIELD

14.1 Introduction 14.2 Economics of turbocharged and air-cooled PFBCs 14.3 Economics of first generation PFBC without hot gas filtration 14.4 Economics of first generation PFBC with hot gas filtration 14.5 Economics of second generation PFBC 14.6 Summary of COE for different types of PFBC technologies

515

515 520 523 525 530 533

xviii CONTENTS

14.7 General economic considerations of PFBC systems 14.8 A word about modularity 14.9 The economics of using lignite and low rank coals 14.10 Future PFBC economics References

Addendum J. WHEELDON

15 Experimental and demonstration plants P.E. BOTROS

15.1 Summary 15.2 Introduction

15.2.1 R&D activities 15.2.2 The CCT program

15.3 Background 15.4 Status and technology needs

15.4.1 Status 15.4.2 Technology needs

15.5 PFBC first generation, combined cycle 15.5.1 Grimethorpe- Feed, erosion, and clean-up 15.5.2 New York University - Particle removal 15.5.3 American Electric Power- Tidd Plant 15.5.4 Vartan 15.5.5 Escatron 15.5.6 PFBC utility demonstration project 15.5.7 Wakamatsu PFBC demonstration 15.5.8 The Polish project 15.5.9 Deutsche Babcock's project 15.5.10 Dairyland-Iowa Power-Des Moines PFBC

15.6 PFBC second generation, advanced cycle 15.7 Some PFBC support activities

15.7.1 Babcock & Wilcox-coal devolatization 15.7.2 METC-0.6 m warm PFBC

15.8 Abbreviations and acronyms References

Index

535 536 537 538 541

542

555

555 556 556 557 557 559 559 562 563 563 565 569 571 572 574 576 576 577 578 581 590 590 593 594 595

599