Experimental Study On The Influence Of Pretreatment On Biomass Pyrolysis Characteristics

Biomass is an ideal renewable energy. More and more people pay much attention on the effective exploitation and utilization of biomass. Pyrolysis is a basic thermo-chemical technology for biomass utilization. People have made abroad researches on biomass pyrolysis characteristics. However, the reports on the influence of metallic elements on biomass pyrolysis characteristics are very limited. With the supports of National Natural Scientific Foundation of"The study on the mechanism and measures for controlling conversion of target products from biomass pyrolysis", the effects of metallic elements on biomass pyrolysis characteristics were investigated by different pretreatments. It would be helpful for further study on the mechanism of biomass pyrolysis, leading to a higher level of bioenergy transformation and utilization in our country.In this paper two kinds of typical agriculture waste were selected. Both peanut shell and rice straw were pretreated by deashing and salt addition. Each sample was investigated through pyrolysis experiments on a Thermol-Gravimetric Analyzer (TGA).Biomass of two different particle sizes were deashed by distilled water, sulfuric acid and hydrochloric acid. Compared to untreated biomass, the concentration of metallic ions in treated biomass decreased to different degree. Due to deashing, the yields of biomass char have changed and the DTG curves of treated biomass were shifted to high temperature.K2CO3 and dolomite of different concentrations were added into both untreated biomass and acid-washed biomass of less than 100 mesh. K2CO3 had much greater effect on biomass pyrolysis than that of dolomite. Salts strengthened the low-temperature pyrolysis of untreated biomass and high-temperature pyrolysis of acid-washed biomass, respectively.According to the optimal fitting principle, proper order of kinetics, which was 1, has been chosen for all reactions. Kinetic parameters of E and A were determined as well. The effects of various pretreatments on biomass activation energy were investigated, too.In this paper pyrolysis experiments were carried out for deashed biomass and salt-added biomass, and the effects of metallic elements on biomass pyrolysis characteristics were further discussed. It provides valuable references for pretreatment technology study of biomass pyrolysis in future.