Parametric effect of biomass partial hydropyrolysis process in a downer reactor to co-produce high-quality tar and syngas.

Fast partial hydropyrolysis of biomass was carried out at the level with hydrogen concentration of 0% to 30% and temperatures ranging from 700 to 900 °C by using a downer pyrolyzer. A theoretical parametric effect on yields and properties of the hydropyrolysis products were clarified. It was found that the volatile matter evolved during pyrolysis was substantially increased in the presence of hydrogen. The yields of CH, CH and light tar increased with increasing elevated H ratio, CH showed an especially large yield increase. The produced methane mainly comes from the reactions of hydropyrolysis of biomass and secondary hydrogenation of tar. Moreover, the presence of alkali and alkaline earth metals matters was significant catalyzes on both reactions. The CH yield increased with elevating the operating temperature and optimal sweeping-gas flow rate is 150 mL/min. These results will be strengthening regulation of feedstocks-operating-products in the practical Biomass Fast Partial Hydropyrolysis technology.