The Study Of Pyrolysis Characteristics In The Extraction Vanadium Process By Roasting Stone Coal With Biomass

The reserves of coal resources is abundant in China, but the reserves of high-quality coal is lacking. The stone coal is an abundant low-quality coal, and the vanadium, which is rich in it, has a wide application field and value. The traditional vanadium extraction process of stone coal sodium by roasting not only consume a large number of high-quality coal, but also produce polluting gases in the production process. In this paper the biomass as a kind of regenerative clean energy takes the place of high-quality coal in roasting process, which not only saves the high-quality resources, but also reduce the environmental pollution caused by it.Because pyrolysis is the most important and necessary way in the thermochemical conversion process of coal and biomass. This paper focuses on the research of pyrolysis. Different pyrolysis experiments on the stone coal with two biomass-corn stalks and sawdust under different conditions by using thermogravimetric analysis to analyze the pyrolysis process and characteristics of stone coal and biomass, then the impact of biomass to the stone coal pyrolysis process and the impact of heating rate on pyrolysis are analyzed. The reaction series is determined and the kinetics model is established at the same time, from which the reaction kinetics parameters could be calculated. Above all, an elaborate analysis of the pyrolysis characteristics is presented in this paper.The experimental results show that: the temperature and the activation energy in the stone coal active pyrolysis stage are much higher than the two kinds of biomass with the affection of its composition and structure characteristics. The temperature interval of them dramatic pyrolysis is difficult to have overlapping area. But in the process of stone coal and biomass mixed pyrolysis, it can be found out that the presence of stone coal inhibits biomass pyrolysis, but the gaseous H2 and solid K2O、Na2O 、 CaO and other products of biomass pyrolysis in advance play a role in promoting stone coal pyrolysis from the change rule of peak temperature Tmax and activation energy E in rhe stone coal and biomass pyrolysis stage respectively. The mixing ratio is 3:7, which is the most conductive to the stone coal pyrolysis. And the increase of the heating rate speeds up the pyrolysis rate of sample, but it also appeared obvious phenomenon of “heat transfer delay”. Too fast or slow heating rate is not conductive to the stone coal pyrolysis, and the best heating rate is 20℃/min.