High-Energy-Density Fuels for Advanced Propulsion

This book comprehensively and systematically demonstrates the theory and practice of designing, synthesizing and improving the performance of fuels. The contents range from polycyoalkane fuels, strained fuels, alky-diamondoid fuels, hypergolic and nanofluid fuels derived from fossil and biomass. All the chapters together clearly describe the important aspects of high-energy-density fuels including molecular design, synthesis route, physiochemical properties, and their application in improving the aerocraft performance. Vivid schematics and illustrations throughout the book enhance the accessibility to the relevant theory and technologies. This book provides the readers with fundamentals on high-energy-density fuels and their potential in advanced aerospace propulsion, and also provides the readers with inspiration for new development of advanced aerospace fuels.

Preface xiii

About the Authors xv

Acknowledgments xvii

1 Introduction 1
Ji‐Jun Zou

Reference 3

2 Development History and Basics of Aerospace Fuels 5
Xiangwen Zhang and Tinghao Jia

2.1 Introduction 5

2.2 General Properties and Requirements of Aerospace Fuels 6

2.2.1 Density 7

2.2.2 Low‐Temperature Fluidity 8

2.2.2.1 Viscosity 8

2.2.2.2 Freezing Point 10

2.2.3 Thermal Oxidation Stability 11

2.2.4 Prediction of Jet Fuel Performance 12

2.3 Development of Aerospace Fuels 12

2.3.1 Aviation Gas Turbine Engine Fuels (Petroleum Fuels) 12

2.3.2 Development of Russian Aerospace Fuels 15

2.3.3 High‐Thermal‐Oxidative‐Stability Fuels 15

2.3.4 Current Fuels 17

2.3.5 Future Fuels 19

2.4 High‐Energy‐Density Fuels 21

2.4.1 RJ‐4 21

2.4.2 RJ‐5 and Related Fuels 22

2.4.3 JP‐10, JP‐9, and RJ‐7 22

2.4.4 Strained and Diamondoid Fuels 25

2.4.5 Gelled Fuels 26

2.5 Non‐petroleum Fuels 27

2.5.1 F‐T Fuels 28

2.5.2 Bio‐aviation Fuels 28

2.5.3 Perspectives 31

References 33

3 Design and Synthesis of High‐Density Polycyoalkane Fuels 39
Ji‐Jun Zou and Chengxiang Shi

3.1 Introduction 39

3.2 Cycloaddition 40

3.2.1 Reaction Pathway 40

3.2.2 Cycloaddition Catalysts 44

3.3 Hydrogenation 50

3.3.1 Hydrogenation of Dicyclopentadiene 50

3.3.1.1 Hydrogenation Mechanism 50

3.3.1.2 Hydrogenation Catalysts 51

3.3.1.3 Hydrogenation Kinetics 54

3.3.2 Hydrogenation of Tricyclopentadiene 67

3.3.2.1 Hydrogenation Mechanism 67

3.3.2.2 Hydrogenation Catalysts 69

3.3.2.3 Hydrogenation Kinetics 70

3.4 Isomerization 74

3.4.1 Isomerization of Tetrahydrodicyclopentadiene 74

3.4.2 Isomerization of Tetrahydrotricyclopentadiene 81

3.5 Other Reactions and Procedures 90

3.5.1 Alternative Isomerization–Hydrogenation Synthesis 90

3.5.2 One‐Step Synthesis of exo‐Tetrahydrodicyclopentadiene 95

References 97

4 Design and Synthesis of High‐Density Diamondoid Fuels 101
Lun Pan and Jiawei Xie

4.1 Introduction 101

4.2 Synthesis of Alkyl Diamondoids via Acid‐Catalyzed Rearrangement 102

4.3 Synthesis of Alkyl Diamondoids via IL‐Catalyzed Rearrangement 112

4.3.1 Rearrangement of Tetrahydrotricyclopentadiene 114

4.3.2 Rearrangement of Tetrahydrodicyclopentadiene 120

4.3.3 Rearrangement of Other Polycycloalkanes 127

4.3.4 Rearrangement of Biomass‐Derived Hydrocarbons 134

4.4 Synthesis of Alkyl Diamondoids via Zeolite‐Catalyzed Rearrangement 135

4.5 Alkylation and Other Chemical Synthesis Methods 138

4.6 Basic Properties of Alkyl Diamondoids 142

References 144

5 Design and Synthesis of High‐Energy Strained Fuels 149
Ji‐Jun Zou, Junjian Xie, Yakun Liu, and Chi Ma

5.1 Introduction 149

5.2 Quadricyclane Fuel 149

5.2.1 Properties and Synthesis of Quadricyclane 149

5.2.2 Homogeneous Photosensitizers 152

5.2.2.1 Triplet Sensitizer 152

5.2.2.2 Transition‐Metal‐Compound‐Based Sensitizer 153

5.2.3 Heterogeneous Photocatalysis 155

5.2.3.1 Zinc and Cadmium Oxides and Sulfides 155

5.2.3.2 Modified Zeolites 155

5.2.3.3 Metal‐Doped TiO2 156

5.2.3.4 Ti‐Containing MCM‐41 161

5.2.3.5 Combination of Metal Doping and Framework Ti Species 164

5.2.3.6 Mechanism of Heterogeneous Photocatalysis 167

5.2.4 Utilization of Quadricyclane 168

5.3 Cyclopropane Fuel 170

5.3.1 Organometallic Carbenoid‐Mediated Cyclopropanation 170

5.3.1.1 Zinc Carbenoid‐Mediated Cyclopropanation 171

5.3.1.2 Samarium Carbenoid‐Mediated Cyclopropanation 174

5.3.1.3 Lithium Carbenoid‐Mediated Cyclopropanation 175

5.3.1.4 Metallic Aluminum Carbenoid‐Mediated Cyclopropanation 177

5.3.2 Transition Metal Carbene‐Mediated Cyclopropanation 181

5.3.2.1 Diazomethane System 183

5.3.2.2 Copper Catalytic System 185

5.3.2.3 Other Transition Metal Catalyst Systems 187

5.3.3 Other Cyclopropanation Methods 190

5.3.4 Fuel Synthesis and Mechanism 190

5.3.4.1 Cyclopropanation of endo‐DCPD with Monomeric IZnCH2I in Gas Phase 193

5.3.4.2 Cyclopropanation of endo‐DCPD with Monomeric IZnCH2I in Diethyl Ether Solvent 197

5.3.4.3 Cyclopropanation of endo‐DCPD with (ICH2)2Zn in Diethyl Ether Solvent 201

5.4 Spiro and Caged Fuels 202

5.4.1 Spiro‐Fuels 203

5.4.2 PCU Monomer, Dimers, and Derivatives 209

5.4.2.1 PCU Monomer 209

5.4.2.2 PCU Dimers 210

5.4.2.3 PCU Derivatives 214

5.4.3 Cubane and Derivatives 218

5.4.4 Other Caged Fuels 222

References 224

6 Design and Synthesis of High‐Density Fuels from Biomass 241
Ji‐Jun Zou and Genkuo Nie

6.1 Introduction 241

6.2 Carbon‐Increasing Reaction Strategies 244

6.2.1 Chain and Ring Increasing by Hydroxyalkylation and Alkylation 244

6.2.1.1 Synthesis of Branched Monocyclic Hydrocarbons by Hydroxylalkylation and Alkylation 250

6.2.1.2 Synthesis of Branched Monocyclic Hydrocarbons by Alkylation 252

6.2.1.3 Synthesis of Branched Multicyclic Hydrocarbons by Alkylation 254

6.2.2 Chain and Ring Increasing by Aldol Condensation 256

6.2.2.1 Synthesis of Branched Monocyclic and Multicyclic Hydrocarbons by Aldol Condensation 256

6.2.2.2 Catalyst Design in the Synthesis of Bi‐ to Tetra‐Five/Six‐Membered Ring Hydrocarbons 260

6.2.3 Ring Increasing by Diels–Alder Cycloaddition 260

6.2.3.1 Synthesis of Multicyclic Hydrocarbons Using Terpinenes 262

6.2.3.2 Synthesis of Branched Multicyclic Hydrocarbons Using 2‐MF 265

6.2.3.3 Synthesis of Branched Monocyclic Hydrocarbons Using Diacetone Alcohol 267

6.2.3.4 Synthesis of JP‐10 Using Furfuryl Alcohol 267

6.2.4 Ring Increasing by Oligomerization 267

6.2.4.1 Synthesis of Multicyclic Hydrocarbons Using Pinene 269

6.2.4.2 Synthesis of Multicyclic Hydrocarbons Using Cyclenes 271

6.2.5 Ring Increasing by Combined Reactions 272

6.2.5.1 Robinson Annulation 272

6.2.5.2 Reductive Coupling 274

6.2.5.3 Guerbet Reaction 275

6.2.6 Fused Cycle Constructing by Skeleton Rearrangement 275

6.2.7 Integrated Reaction Strategies 277

6.2.7.1 Dual‐Bed Catalyst System 278

6.2.7.2 One‐Pot Reaction 279

6.2.7.3 Multistep Coupling Reaction 280

6.2.7.4 Cellulose Co‐conversion with Polyethylene via Catalytically Combined Processes 283

References 283

7 Design and Synthesis of Nanofluid Fuels 291
Lun Pan, Xiu‐Tian‐Feng E, Jinwen Cao, and Kang Xue

7.1 Introduction 291

7.2 Synthesis and Properties of Nanofluid Fuels 292

7.2.1 Single‐Step Methods 293

7.2.1.1 Physical Methods 293

7.2.1.2 Chemical Methods 299

7.2.2 Two‐Step Methods 303

7.3 Methods to Evaluate Stability of Nanofluids 305

7.3.1 Sedimentation Photograph Capturing 305

7.3.2 Sedimentation Balance Method 305

7.3.3 Centrifugation Method 305

7.3.4 ζ‐Potential Measurement 306

7.3.5 UV–Vis Spectrophotometer 308

7.3.6 Light Scattering Method 310

7.3.7 Three‐Omega Method 310

7.4 Approaches to Enhance Stability of Nanofluids 310

7.4.1 Mechanical Mixing 311

7.4.2 pH Control 312

7.4.3 Surfactants 313

7.4.4 Surface Modification 313

7.5 Typical High‐Energy Nanofluid Fuels 315

7.5.1 Boron‐Based Nanofluids 315

7.5.1.1 Preparation of Stable Boron‐in‐Jet Fuel Nanofluids 316

7.5.1.2 Dispersion of Boron‐Based Nanofluids 317

7.5.2 Aluminum‐Based Nanofluids 320

7.6 Physical Properties of Nanofluid Fuels 322

7.6.1 Density and Energy 322

7.6.2 Viscosity 323

7.6.3 Surface tension 328

7.6.4 Latent Heat of Vaporization 329

7.6.5 Combustion Characteristics 331

7.6.6 Evaporation Characteristics 337

7.7 Formulation and Synthesis of Gelled Fuels 341

7.7.1 Gel Formulation 341

7.7.2 Gel Preparation and Gelation Mechanism 346

7.8 Rheological Behavior 348

7.9 Atomization Behavior 352

7.10 Combustion Behavior 356

References 361

8 Design and Synthesis of Green Hypergolic Ionic Liquid Fuels 377
Xiangwen Zhang and Yong‐Chao Zhang

8.1 Introduction 377

8.2 Development History of Hypergolic Ionic Liquids 378

8.3 Physicochemical Properties of Hypergolic Ionic Liquids 379

8.3.1 Thermal Properties 379

8.3.2 Density 380

8.3.3 Viscosity 380

8.3.4 Heat of Formation 380

8.3.5 Ignition Delay Time 381

8.3.6 Specific Impulse 382

8.4 Hypergolic Ionic Liquids 382

8.4.1 Hypergolic Ionic Liquids Based on Dicyanamide Anions 382

8.4.2 Hypergolic Ionic Liquids Based on Nitrocyanamide Anions 397

8.4.3 Hypergolic Ionic Liquids Based on Boronium‐Based and B─H Bond‐Rich Anions 402

8.4.4 Hypergolic Ionic Liquids Based on Other Anions 421

References 431

9 Combustion Properties of Fuels and Methods to Improve Them 437
Lun Pan and Xiu‐Tian‐Feng E

9.1 Introduction 437

9.2 Typical Equipment Used in Combustion Experiment 439

9.2.1 Rapid Compressor 439

9.2.2 Shock Tube 441

9.2.2.1 Heated Shock Tube 441

9.2.2.2 Aerosol Shock Tube 441

9.2.3 Hot Plate 446

9.2.4 Laser Ignition 447

9.2.5 Constant‐Volume Strand Burner 447

9.3 Combustion and Ignition Characters 450

9.3.1 Ignition Probability 450

9.3.2 Ignition Temperature 450

9.3.3 Ignition Delay Time 453

9.3.4 Combustion Rate 455

9.4 Methods to Enhance Ignition and Combustion 458

9.4.1 Effect of NP Concentration on Ignition and Combustion 458

9.4.2 Effect of Surfactants or Dispersants on Ignition and Combustion 461

9.4.3 Effect of Nanoparticle Characteristics on Ignition and Combustion 462

9.5 Combustion Mechanism of Nanofluid Fuels 464

References 470

Index 475

Ji-Jun Zou, PhD, is the Department Head of Chemical Technology and Chair Professor at the School of Chemical Engineering and Technology in Tianjin University, China. He has received several awards including Technological Leading Scholar of 10000 Talent project (2017), and Changjiang Young Scholar by the Ministry of Education (2016). An Associate Editor of RSC Advances, he has also authored or coauthored more than 150 papers and 30 patents.

Xiangwen Zhang, PhD, is the Director of Key Laboratory of advanced fuel and chemical propellant of Ministry of Education. His research interests include fuel processing technology and reaction engineering. He has authored/coauthored more than 300 papers and 30 patents.

Lun Pan, PhD, is an Associate Professor whose research interests focus on the design and synthesis of functional photocatalysts; their related modulation of morphology, facets, and surface defects; and their applications in photocatalysis, such as in photocatalytic isomerization for synthesis of advanced fuels. He has published more than 50 papers and 20 patents.

Covers the theory and practice of designing, synthesizing, and improving the performance of fuels

This book provides readers with the fundamentals on high-energy-density fuels and their potential in advanced aerospace propulsion. It comprehensively and systematically demonstrates both the theory and practice of creating, processing, and refining the performance of fuels, all while connecting the past, present, and future of fuel chemistry and technology. It covers a wide range of fuels including polycyoalkane fuels, strained fuels, alky-diamondoid fuels, and hypergolic and nanofluid fuels derived from fossil and biomass. It also describes the important aspects of high-energy-density (HED) fuels, including molecular design, synthesis route, physiochemical properties, and their application in improving aircraft performance. In addition, the book features vivid schematics and illustrations throughout to enhance accessibility to the relevant theory and technologies.

High-Energy-Density Fuels for Advanced Propulsion begins by introducing readers to the topic before delving into the development history and basics of aerospace fuels. It discusses the general properties and requirements of aerospace fuels, as well as the overall development. The book also covers the design and synthesis of green hypergolic liquid fuels, the formulation and synthesis of gelled fuels, the combustion properties of fuels and the methods for improving them, and more.

• A much-needed, complete overview of an important topic on fuel chemistry and technology for a range of fuels, including aerospace propulsion technology
• Provides readers with inspirations for new development of advanced aerospace fuels
• Discusses how HED fuels can improve the performance of aircraft
• Offers chapters covering fuels such as polycyoalkane, strained, alky-diamondoid, hypergolic, and nanofluid fuels

High-Energy-Density Fuels for Advanced Propulsion is an excellent resource for those working in the fields of fuel chemistry, fuel technology, and aerospace propulsion technology, and is an ideal reference book for researchers, engineers, and students majoring in chemical science and engineering, mechanical engineering, and aerospace engineering.