Pyrolysis, pressurized charcoal yield

Knowledge of the effects of various independent parameters such as biomass feedstock type and composition, reaction temperature and pressure, residence time, and catalysts on reaction rates, product selectivities, and product yields has led to development of advanced biomass pyrolysis processes. The accumulation of considerable experimental data on these parameters has resulted in advanced pyrolysis methods for the direct thermal conversion of biomass to liquid fuels and various chemicals in higher yields than those obtained by the traditional long-residence-time pyrolysis methods. Thermal conversion processes have also been developed for producing high yields of charcoals from biomass. 

In the case of oak wood used to manufacture charcoal in Missouri kilns, pyrolysis at 1.0 MPa increases the fixed-carbon yield from <24 wt% in an externally heated retort (or the Missouri kiln) to 29.9 wt% in the pressure vessel. The time requirement is reduced from =10,000 min for the Missouri kiln to about 70 min in the pressure vessel. 

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