Influence of Metal Ions on Biomass Pyrolysis Process

In order to understand the behavior of biomass pyrolysis, a series of pretreatment biomass were prepared with acid-washing and metal impregnated methods. The effects of metal ions on the yields of tar, char and gas from straw pyrolysis were analyzed in our lab scale fixed-bed reactor. Alkali metal and alkaline earth metal ions affect biomass pyrolysis process and the products heavily. The decreasing metal ions result in declining yield of semi-char and increasing yields of tar and gas. Meanwhile, the pyrolysis temperature corresponding maxium yield of tar increases. There exist marked catalytic effect of potassium, calcium and magnesium cations on the cracking of large molecular weight parts of tar and semi-char formation via recombination reaction of tar. As cause a higher production of char while a decrease of tar and gas production.