Experimental study of the effect of acid-washing pretreatment on biomass pyrolysis

The influence of acid-washing pretreatment on biomass pyrolysis was experimentally studied in a radiation reactor. The results show that the metal ions content of rice husk treated by acids is reduced markedly. The yield of tar from pyrolysis of rice husk treated by 7% HCl increased from 41.74 to 52.88%, and the yields of gas and char decrease. The influence will be more remarkable with the increase of acid concentration. The gaseous products of pyrolysis of HCl-treated rice husk mainly consist of CO and CO2 which yields decreased metal ions content when compared with those of the raw sample. The effects of H2SO4, HCl, and H3PO4 on biomass pyrolysis are different. HCl has the strongest effect on the pyrolysis products distribution because of the least amounts of K+ remained after HCl treatment. The microstructures of biomass are damaged seriously by H2SO4 treatment.