Microwave pyrolysis of wheat straw: product distribution and generation mechanism.

Microwave pyrolysis of wheat straw is studied, combined with analysis of products, the distribution and generation pathway of products are investigated. Only a small amount of volatiles released when microwave pyrolysis of pure straw. Mixtures of adding CuO and Fe3O4 can pyrolyze, and the majority in pyrolysis products is in liquid-phase. Severe pyrolysis occur after adding carbon residue, the CO content in pyrolysis gas products is high, and the maximum volume content of H2 can exceed 35 vol.%. The high-temperature is helpful for increasing the yield of combustible gas in gaseous products, in particular the H2 production, but also helpful for improving the conversion of sample. Pyrolysis is carried out layer by layer from the inside to outside. As the internal material firstly pyrolyze and pyrolysis products released pass through the low temperature zone, the chance of occurrence of secondary reactions is reduced.