Pyrolysis of grain screenings in a batch reactor

Abstract

AbstractA preliminary study of the pyrolysis of grain screenings (wheat) has been carried out using a batch pyrolysis unit operating at atmospheric pressure. Grain screenings are the materials removed mechanically from grains (wheat, rapeseed, barley, etc.) by cleaning or separating equipment in grain elevators. Reaction conditions were varied to determine the effect of these changes on the final product (tar, gas, and char). The reaction variables manipulated included temperature (600–800°C), nitrogen carrier gas velocity, and potassium carbonate catalyst. It was found that the yields of ethylene were higher than those of ethane. These hydrocarbons were accompanied by smaller but significant yields of hydrogen and C4 to C6 hydrocarbons. The grain screenings impregnated with 15 wt% potassium carbonate catalyst gave higher synthesis gas yields with a H2/CO mole ratio up to 4.1. With the experimental set up used in the present study, the mass balances achieved were low and ranged between 65 and 77% of the weight of the grain screenings used.