Efficiency of Biomass Energy

Krzysztof J. Ptasinski, Ph.D., D.Sc., has over 40 years of experience in academic teaching and research in chemical engineering and energy technology. He has held appointments at the Eindhoven University of Technology and the University of Twente (the Netherlands) as well as the Warsaw University of Technology and as visiting professor at the Silesian University of Technology (Poland). His pioneering research on application of exergy analysis to biomass and bioenergy is internationally acclaimed. He is the author and co-author of more than 200 publications, including 19 book chapters and 75 research papers. Currently he serves as an Executive Editor Biomass and Bioenergy – Energy, The International Journal.

Preface xv

Acknowledgments xix

About the Author xxi

PART I | Background and Outline

Chapter 1 | Bioenergy Systems: An Overview 3

1.1 Energy and the Environment 3

1.2 Biomass as a Renewable Energy Source 13

1.3 Biomass Conversion Processes 22

1.4 Utilization of Biomass 27

1.5 Closing Remarks 34

References 34

Chapter 2 | Exergy Analysis 37

2.1 Sustainability and Efficiency 37

2.2 Thermodynamic Analysis of Processes 42

2.3 Exergy Concept 52

2.4 Exergetic Evaluation of Processes and Technologies 67

2.5 Renewability of Biofuels 81

2.6 Closing Remarks 86

References 86

PART II | Biomass Production and Conversion

Chapter 3 | Photosynthesis 93

3.1 Photosynthesis: An Overview 93

3.2 Exergy of Thermal Radiation 99

3.3 Exergy Analysis of Photosynthesis 106

3.4 Global Photosynthesis 116

3.5 Closing Remarks 120

References 120

Chapter 4 | Biomass Production 123

4.1 Overview 123

4.2 Efficiency of Solar Energy Capture 133

4.3 Fossil Inputs for Biomass Cultivation and Harvesting 140

4.4 Fossil Inputs for Biomass Logistics 146

4.5 Closing Remarks 150

References 150

Chapter 5 | Thermochemical Conversion: Gasification 153

5.1 Gasification: An Overview 153

5.2 Gasification of Carbon 171

5.3 Gasification of Biomass 183

5.4 Gasification of Typical Fuels 191

5.5 Closing Remarks 198

References 198

Chapter 6 | Gasification: Parametric Studies and Gasification Systems 203

6.1 Effect of Fuel Chemical Composition on Gasification Performance 203

6.2 Effect of Biomass Moisture Content, Gasification Pressure, and Heat Addition on Gasification Performance 211

6.3 Improvement of Gasification Exergetic Efficiency 215

6.4 Gasification Efficiency Using Equilibrium versus Nonequilibrium Models 230

6.4.1 Quasi-Equilibrium Thermodynamic Models 231

6.4.2 Comparison of Gasification Efficiency 231

6.5 Performance of Typical Gasifiers 233

6.5.1 Comparison of FICFB and Viking Gasifiers 233

6.5.2 Fluidized-Bed Gasifiers for the Production of H2-Rich Syngas 238

6.5.3 Downdraft Fixed-Bed Gasifier 241

6.5.4 Updraft Fixed-Bed Gasifier 242

6.6 Plasma Gasification 244

6.6.1 Plasma Gasification Technology 244

6.6.2 Plasma Gasification of Sewage Sludge 244

6.7 Thermochemical Conversion in Sub- and Supercritical Water 246

6.7.1 Conversion of Wet Biomass in Hot Compressed Water 246

6.7.2 Supercritical Water Gasification (SCWG) 247

6.7.3 Hydrothermal Upgrading (HTU) under Subcritical Water Conditions 251

6.8 Closing Remarks 253

References 253

PART III | Biofuels First-Generation Biofuels

Chapter 7 | Biodiesel 261

7.1 Biodiesel: An Overview 261

7.1.1 Introduction 261

7.1.2 Historical Development 262

7.1.3 Chemistry 263

7.1.4 Feedstocks 265

7.1.5 Production Process 266

7.1.6 Biodiesel as Transport Fuel 268

7.1.7 Energy, Environmental, and Economic Performance 269

7.2 Biodiesel from Plant Oils 272

7.2.1 Exergy Analysis of Transesterification 272

7.2.2 Exergy Analysis of Overall Production Chain 275

7.3 Biodiesel from Used Cooking Oil 278

7.3.1 Exergy Analysis of Biodiesel Production 278

7.3.2 Exergy Analysis of Overall Production Chain 281

7.4 Biodiesel from Microalgae 281

7.4.1 Introduction 281

7.4.2 Exergy Analysis of Transesterification of Algal Oil 282

7.4.3 Exergy Analysis of Overall Production Chain of Algal Biodiesel 284

7.5 Closing Remarks 286

References 286

Chapter 8 | Bioethanol 289

8.1 Bioethanol: An Overview 289

8.1.1 Introduction 289

8.1.2 Historical Development 290

8.1.3 Ethanol as Transport Fuel 291

8.1.4 Chemistry 293

8.1.5 Bioethanol Production Methods 295

8.1.6 Energy, Environmental and Economic Aspects 302

8.2 Exergy Analysis of Ethanol from Sugar Crops 305

8.2.1 Introduction 305

8.2.2 Ethanol from Sugarcane 306

8.2.3 Exergetic Performance of Sugarcane Ethanol Plants for Various Cogeneration Configurations 310

8.2.4 Ethanol from Sugar Beets 313

8.2.5 Renewability of Ethanol from Sugar Crops 315

8.3 Exergy Analysis of Ethanol from Starchy Crops 317

8.3.1 Introduction 317

8.3.2 Corn Ethanol: Exergy Analysis 317

8.3.3 Corn Ethanol: Cumulative Exergy Consumption (CExC) and Renewability 319

8.3.4 Wheat Ethanol 322

8.4 Exergy Analysis of Lignocellulosic Ethanol (Second Generation) 323

8.4.1 Introduction 323

8.4.2 Ethanol from Wood (NREL Process) 324

8.4.3 Impact of Biomass Pretreatment and Process Configuration 328

8.4.4 Comparison of Exergetic Efficiency 330

8.4.5 Renewability of Lignocellulosic Ethanol from Tropical Tree Plantations 331

8.5 Alternative Ethanol Processes 332

8.5.1 Fossil Ethanol from Mineral Oil 332

8.5.2 Ethanol via Water Electrolysis 333

8.6 Closing Remarks 334

References 334

Second-Generation Liquid Biofuels

Chapter 9 | Fischer–Tropsch Fuels 341

9.1 Fischer–Tropsch Synthesis: An Overview 341

9.1.1 Introduction 341

9.1.2 Historical Development 342

9.1.3 Process Chemistry 343

9.1.4 Comparison of F-T Fuels to Conventional Transport Fuels 345

9.1.5 Process Design 346

9.1.6 Process Performance 348

9.2 Exergy Analysis of Coal-to-Liquid (CTL) Process 351

9.2.1 Description of CTL Process 351

9.2.2 Mass Balance and Energy Analysis 353

9.2.3 Exergy Analysis 354

9.3 Exergy Analysis of Gas-to-Liquid (GTL) Processes 355

9.3.1 GTL Process with Tail Gas Recycling: Internal and External 356

9.3.2 Impact of Reformer Temperature on GTL Efficiency: External Tail Gas Recycling 361

9.4 Exergy Analysis of Biomass-to-Liquid (BTL) Processes 365

9.4.1 Introduction 365

9.4.2 Once-Through F-T Process 366

9.4.3 Impact of Biomass Feedstock on Process Efficiency 373

9.4.4 Reforming and Recycling of F-T Reactor Tail Gas 377

9.4.5 Recycling of F-T Reactor Tail Gas to Biomass Gasifier 382

9.5 Closing Remarks 383

References 383

Chapter 10 | Methanol 387

10.1 Methanol: An Overview 387

10.1.1 Introduction 387

10.1.2 Historical Development 388

10.1.3 Chemistry 389

10.1.4 Methanol as Transport Fuel 390

10.1.5 Process Design 392

10.1.6 Process Performance 393

10.2 Methanol from Fossil Fuels 396

10.2.1 Methanol from Natural Gas 396

10.2.2 Methanol from Coal 400

10.3 Methanol from Biomass 405

10.3.1 Methanol from Waste Biomass (Sewage Sludge) 405

10.3.2 Other Biomass-Based Methanol Processes 413

10.4 Closing Remarks 414

References 415

Chapter 11 | Thermochemical Ethanol 419

11.1 Thermochemical Ethanol: An Overview 419

11.1.1 Introduction 419

11.1.2 Process Chemistry 420

11.1.3 Catalysts for Ethanol Synthesis 422

11.1.4 Process Design 423

11.1.5 Energy, Environmental and Economic Aspects 426

11.2 Exergy Analysis 427

11.2.1 Process Description 428

11.2.2 Mass and Energy Balances (Rh-Based Catalyst) 431

11.2.3 Exergy Analysis (Rh-Based Catalyst) 433

11.2.4 Impact of Ethanol Synthesis Catalyst (MoS2-Based Target Catalyst) 435

11.2.5 Impact of Gasification Temperature 438

11.3 Closing Remarks 439

References 440

Chapter 12 | Dimethyl Ether (DME) 445

12.1 Dimethyl Ether: An Overview 445

12.1.1 Introduction 445

12.1.2 Historical Development 446

12.1.3 Process Chemistry 447

12.1.4 DME as Energy Carrier 448

12.1.5 Production Technology 449

12.1.6 Energy, Environmental, and Economic Aspects 451

12.2 Dimethyl Ether from Fossil Fuels 452

12.2.1 DME from Natural Gas 452

12.2.2 DME from Coal 458

12.2.3 DME from Co-Feed of Natural Gas and Coal 462

12.3 Dimethyl Ether from Biomass 462

12.3.1 DME via Indirect Steam Gasification 462

12.3.2 Influence of Syngas Preparation Method on Process Efficiency 468

12.4 Closing Remarks 472

References 472

Chapter 13 | Hydrogen 475

13.1 Hydrogen: An Overview 475

13.1.1 Introduction 475

13.1.2 History: from Discovery to Hydrogen Economy 476

13.1.3 Chemistry of Hydrogen Production 477

13.1.4 Hydrogen Use 479

13.1.5 Hydrogen Storage 480

13.1.6 Production Methods 481

13.1.7 Energy, Environmental, and Economic Performance 482

13.2 Exergy Analysis of Hydrogen from Fossil Fuels 485

13.2.1 Hydrogen from Natural Gas 485

13.2.2 Comparison of Efficiency for Hydrogen-from-Natural Gas Processes 489

13.2.3 Hydrogen-from-Coal Gasification 490

13.2.4 Comparison of Efficiency for Hydrogen-from-Coal Processes 493

13.3 Exergy Analysis of Hydrogen from Water Electrolysis 494

13.3.1 Process Description 494

13.3.2 Mass and Energy Balances 495

13.3.3 Exergy Analysis 495

13.4 Exergy Analysis of Future Hydrogen Production Processes 496

13.4.1 Thermochemical Cycles 497

13.4.2 Geothermal Energy 499

13.4.3 Solar Energy 500

13.5 Exergy Analysis of Hydrogen Production from Biomass Gasification 501

13.5.1 Exergy Analysis of Hydrogen from Wood 501

13.5.2 Influence of Biomass Feedstocks on Exergetic Efficiency 506

13.5.3 Influence of Gasification System Configurations on Exergetic Efficiency 507

13.5.4 Comparison of Efficiency for Hydrogen-from-Biomass Gasification 511

13.6 Exergy Analysis of Biological Hydrogen Production 512

13.6.1 Process Description 512

13.6.2 Mass and Energy Balances 514

13.6.3 Exergy Analysis 515

13.7 Closing Remarks 517

References 517

Chapter 14 | Substitute Natural Gas (SNG) 523

14.1 Substitute Natural Gas: An Overview 523

14.1.1 Introduction 523

14.1.2 Historical Development 524

14.1.3 Chemistry of Methanation 526

14.1.4 Natural Gas as Energy Carrier 527

14.1.5 SNG Production Technology 529

14.1.6 Energy, Environmental and Economic Aspects 530

14.2 SNG from Coal 533

14.2.1 Description of Coal-to-SNG Process 533

14.2.2 Process Modeling 537

14.2.3 Mass and Energy Balances 537

14.2.4 Exergy Analysis 538

14.2.5 Overview of Coal-to-SNG Processes 540

14.3 SNG from Biomass Gasification 540

14.3.1 SNG via Wood Gasification 540

14.3.2 Comparison of SNG Production from Various Biomass Feedstocks 550

14.3.3 Overview of Biomass-to-SNG Processes 555

14.4 Closing Remarks 555

References 556

PART IV | Bioenergy Systems

Chapter 15 | Thermal Power Plants, Heat Engines, and Heat Production 561

15.1 Biomass-Based Power and Heat Generation: An Overview 561

15.1.1 Introduction 561

15.1.2 Historical Development 563

15.1.3 Technologies for Power Generation from Biomass 564

15.1.4 Biofuels in Internal Combustion Engines and Gas Turbines 567

15.1.5 Biomass Heating Systems 568

15.1.6 Performance and Cost of Power Generation Systems 569

15.1.7 Environmental Aspects 571

15.2 Biomass Combustion Power Systems 571

15.2.1 Introduction 571

15.2.2 Biomass Steam Cogeneration Plant 572

15.2.3 Externally Fired Gas Turbine–Combined Cycle 575

15.2.4 Biomass-Fired Organic Rankine Cycle (ORC) 580

15.3 Biomass Gasification Power Systems 584

15.3.1 Introduction 584

15.3.2 Biomass Integrated Gasification Gas Turbine–Combined Cycle (BIG/GT-CC) 585

15.3.3 Improving Efficiency BIG/GT-CC Plants 588

15.3.4 Biomass Integrated Gasification Internal Combustion Engine–Combined Cycle (BIG/ICE-CC) 589

15.4 Comparison of Various Biomass-Fueled Power Plants 591

15.4.1 Internally and Externally Fired Gas Turbine Simple Cogeneration Cycles 592

15.4.2 Internally and Externally Fired Gas Turbine: Simple and Combined Cycles 597

15.4.3 Comparison of Biomass Combustion and Gasification CHP Plants 602

15.5 Biomass-Fueled Internal Combustion Engines and Gas Turbines 608

15.5.1 Ethanol-Fueled Spark-Ignition Engines 609

15.5.2 Biodiesel-Fueled Compression-Ignition Engines 610

15.5.3 Biofuel-Fired Gas Turbines 612

15.6 Polygeneration of Electricity, Heat, and Chemicals 615

15.6.1 Introduction 615

15.6.2 Methanol Synthesis 615

15.6.3 Ethanol Production 621

15.7 Biomass Boilers and Heating Systems 624

15.7.1 Introduction 624

15.7.2 Biomass Boilers 625

15.7.3 Energy Utilization in Buildings 627

15.8 Closing Remarks 628

References 628

Chapter 16 | Biomass-Based Fuel Cell Systems 633

16.1 Biomass-Based Fuel Cell Systems: An Overview 633

16.1.1 Introduction 633

16.1.2 Historical Development 634

16.1.3 Fuel Cell Fundamentals 635

16.1.4 Fuel Cell Types 636

16.1.5 Fuel Cell Thermodynamics 638

16.1.6 Overview of Biomass-Based Fuel Cell Configurations 640

16.1.7 Energy Efficiency, Cost, and Environmental Impact 642

16.2 Biomass Integrated Gasification–Solid Oxide Fuel Cell (BIG/SOFC) Systems 642

16.2.1 Central Power Production Using BIG/SOFC/GT Systems 643

16.2.2 Other Central Power Production Studies Using BIG/SOFC Systems 647

16.2.3 Distributed Power Production Using BIG/SOFC Systems 648

16.2.4 Integration of Supercritical Water Gasification (SCWG) with SOFC/GT Hybrid System 650

16.3 Biomass Integrated Gasification–Proton Exchange Membrane Fuel Cell (BIG/PEMFC) Systems 652

16.3.1 Distributed Combined Heat and Power Generation Based on Central Hydrogen Production 652

16.3.2 Effect of Hydrogen Quality on Efficiency of Distributed CHP Systems 659

16.4 Fuel Cell Systems Fed with Liquid Biofuels 660

16.4.1 Introduction 660

16.4.2 Maximum Electricity Obtainable from Various Fuels 661

16.4.3 Integrated Fuel Processor–Fuel Cell (FP-FC) System 663

16.4.4 Direct Liquid Fuel Cell Systems 668

16.5 Closing Remarks 669

References 669

Chapter 17 | Biorefineries 673

17.1 Biorefineries: An Overview 673

17.1.1 Introduction 673

17.1.2 Historical Development 674

17.1.3 Chemical Value of Biomass 675

17.1.4 Biorefinery Systems 677

17.1.5 Biorefinery Technology 679

17.2 Comparison of Various Biomass Utilization Routes 681

17.2.1 Biomass Utilization Routes 681

17.2.2 Power Generation 682

17.2.3 Biofuels Production 683

17.2.4 Chemical Biorefinery 683

17.3 Exergy Inputs to Basic Biorefinery Steps 684

17.3.1 Biorefinery Model 684

17.3.2 Processing Simple Carbohydrates into Fermentable Sugars 686

17.3.3 Processing Complex Carbohydrates into Fermentable Sugars 686

17.3.4 Processing Fermentable Sugars into Ethanol 688

17.3.5 Processing Ethanol into Ethylene 689

17.3.6 Fatty Acids Processing 690

17.3.7 Amino Acids Processing 692

17.3.8 Lignin Processing 695

17.3.9 Ash and Residuals Processing 695

17.4 Optimal Biomass Crops as Biorefinery Feedstock 696

17.4.1 Biomass versus Petrochemical Route for the Production of Bulk Chemicals 696

17.4.2 Cumulative Fossil Fuel Consumption in the Biomass Route 697

17.4.3 Cumulative Fossil Fuel Consumption in the Petrochemical Route 698

17.4.4 Fossil Fuel Savings 699

17.4.5 Optimal Crops for Biorefineries 699

17.5 Closing Remarks 702

References 702

Postface 707

Appendixes

Appendix A – Conversion Factors 709

Appendix B – Constants 711

Appendix C – SI Prefixes 713

Glossary of Selected Terms 715

Notation 721

Acknowledgments for Permission to Reproduce Copyrighted Material 729

Author Index 733

Subject Index 745