Modeling of coal pyrolysis under the conditions of an entrained phase reactor

Experimental laboratory work has shown that yield and quality of liquid products from coal pyrolysis can be controlled and optimized to a certain extent by suitable coaction of the primary thermal coal decomposition reactions and the secondary cracking or hydrocracking of the volatiles. The results indicate that favorable process conditions are provided in an entrained phase transport reactor which enables high heating rates for fast primary coal pyrolysis together with optimum residence time of the volatiles for secondary cracking and hydrocracking in the heated reactor zone. From that point of view the question arises how thermal coal decomposition can be described at high heating rates and whether transport limiting processes are involved in the overall reaction step. Especially for reactor design it is necessary to clarify to what extent experimental kinetic data gained at low heating rates can be applied to heating conditions like in a fluidized bed or in an entrained phase reactor.