Co-pyrolysis And Co-gasification Behaviours Of Rice Straw And High Swelling Coal

In order to search for the way of comprehensively utilize biomass resources and high swelling property coal efficiently, this paper investigated co-pyrolysis and co-gasification behaviours of rice straw and bituminous coal, focusing on synergistic effects of both inorganic and orgnic matters between rice straw and high expansibility coal. The main content of this paper are as follows.Firstly, Rice straw and YST coal were pyrolyzed and gaified on the fixed-bed reactor. We qualitatively and quantitively analyze the product distribution and constituents by GC, GC-MS. Results showed that the synergistic effect of co-pyrolysis of rice straw and YST coal mainly contributed to the expansile change of YST coal, as well as the partial inactivation of internal minerals in rice straw. Before 425℃, the experimental char yield was higher than the calculated value, while the liquid and gaseous yields were both lower. When pyrolysis temperature was higher than 425℃, the calculated yield of liquid product was higher than the calculated value; otherwise the gaseous yield was lower. The cumulative amounts of different gases reduced at different extent. The cumulatived amout of COS and H2S increased sharply at low temperature owing to the released of CO and H2 form rice straw. Meanwhile, the amount of COS and H2S decreased at high temperature, which was because of the sulfur-capturing effect of Ca. GC-MS results showed the liquid compounds and relative contents also changed a lot.Secondly, we studied the co-pyrolytic characteristics of acid-washed rice straw and raw coal, as well as the properties of solid production. At low temperature, the high swelling property of coal would inhibite the effusion of volatile matter from rice straw; however, the secondary reaction of liquid product from coal seriously weakened as the damage of expansibility at high temperature. Swelling property and XRD spectra proved that the adding of rice straw will definitely destroy the expansibility of YST coal. And rice straw was able to decrease the graphtatization of YST coal char.Finally, the char obtained from 1:1 blend, as well as admixture of coal char and biomass char blend were gasified on the fixed-bed reactor. Results showed that some changes occurred about the organic constituents of the chars during the co-pyrolysis procedure. This change would improve the gasification reactivity, compared to the gasification of individual material. It also changed the ratio of gaseous product in order to improve the heat value of gases.