9.1 Introduction................................................................................................ 244

9.2 Hydrogen: Energy Carrier........................................................................ 245

9.2.1 Need for Energy Carriers ............................................................. 245

9.2.2 Role of Electricity ........................................................................... 246

9.2.3 Role of Hydrogen ........................................................................... 247

9.3 Hydrogen Production................................................................................ 247

9.3.1 Hydrocarbon Reforming............................................................... 247

9.3.2 Pyrolysis .......................................................................................... 248

9.3.3 Plasma Reforming ......................................................................... 249

9.3.4 Biohydrogen.................................................................................... 249

9.3.5 Hydrogen from Water ................................................................... 249

9.4 Hydrogen Properties ................................................................................. 249

9.4.1 Physical Properties ........................................................................ 249

9.4.2 Chemical Properties ...................................................................... 251

9.4.3 Fuel Properties ............................................................................... 251

9.4.3.1 Minimum Ignition Energy ............................................ 251

9.4.3.2 Flame Speed..................................................................... 252

9.4.3.3 Flame Temperature......................................................... 252

9.4.3.4 Diffusivity ........................................................................ 252

9.4.3.5 Flammability ................................................................... 253

9.4.3.6 Quenching Distance ....................................................... 253

9.4.3.7 Air–Fuel Ratio.................................................................. 253

9.4.3.8 Hydrogen Embrittlement...............................................254

9.4.3.9 Calorific Value ................................................................. 255

9.5 Well-to-Wheels Considerations ............................................................... 255

9.5.1 JRC/EUCAR/CONCAWE Report ............................................... 256

9.6 Hydrogen Economics ................................................................................ 258

9.7 Hydrogen Safety ........................................................................................ 260

9.8 Hydrogen in Fuel Cells ............................................................................. 263

9.9 Fuel Cell Vehicles Hybridization............................................................. 266

9.10 Hydrogen in Spark Ignition Engines ...................................................... 267

9.10.1 Manifold Induction...................................................................... 268

9.10.2 Port Injection................................................................................. 269

9
Hydrogen
Fernando Ortenzi, Giovanni Pede, and Arumugam Sakunthalai Ramadhas
CONTENTS
243