Italian Balestra Type Updraft Rice Hull Gas Producer (1910 - 1944) 216 Chinese Rice Hull Gas Producer 221 Design Considerations for Ash Removal Systems 224 Ash Removal Designs 226 Summary 237 Design Considerations for the Gas Exit 237 Air Injection Designs 243 Design of a Small (2 - 20 hp) Rice Hull Gas Producer 246 Open Core Gas Producer 256 -Mode of Operation 258 Gas Cleaning Train 278 Sieve Plate Scrubber and Dry Packed Bed Filter 280 Experimental Procedures and Results 284 Summary 295 List of Symbols 296 References 298 VIII LIST OF FIGURES FIGURE PAGE 1-1 Energy fractions in gaseous components as a function of the equivalence ratio 4 1-2 Ignition advancement versus hydrogen content of producer gas 9 1-3 Soot formation as a function of H/C and 0/C ratio 11 1-4 Soot formation as a function of H/C ratio 12 1-5 Power output as a function of 12 1-6 Ultimate elemental analysis on an ash and moisture free basis of various biomass fuels 16 1-7 Block diagram of parameters involved in the gasification process 17 5-l Co-current or downdraft gasification 52 5-2 Accumulative mass loss curve 54 5-3 Differential mass loss curve 54 5-4 Differential thermal analysis 55 5-5 Counter-current or updraft gasification 57 5 6 Equilibrium of the water shift reaction as a function of temperature in a fluidized bed rice hull gasifier 61 5-7 Kp(T) as a function of T 62 5-8 Range of computed gas compositions as a function of