(634g) Effects of Acid-Washing Treatment On Pyrolysis Products of Biomass in a Downer Reactor

With an ever-increasing demand for energy and a growing concern on global climate change, biomass has gained much attention as an alternative to fossil fuels in recent decades due to its renewability and CO₂ neurality. Pyrolysis is attractive in the utilization of biomass for energy purpose. In this work, expertimental study has been conducted in a bench-scale CFB downer reactor with an emphasis on the effects of acid-washing treatment on pyrolysis product distribution and product properties. It is found that the removal of inorganic species increases the yield of liquid product and reduces the char formation and gas yield. CO and CO₂ are the dominant components in the gaseous product, which account for over 90%. The concentration of CO in the gaseous product increases after the acid treatment while the CO₂ concentration decreases. Oxygen and water contents in the liquid product is decreased on acid treatment, which leads to relatively high heating value and viscosity. It is found that volatiles in the char derived from the acid treated wheat staw is higher than that from the raw wheat straw. This may suggest a longer residence time is needed for the pyrolysis of the acid treated wheat straw in order to obtain the maximal yield of volatile matter.