Experimental Research On The Characteristics Of Coal And Biomass Pyrolysis In The Fix-bed Reactor

Co-utilization of coal and biomass is an effective way to ease energy shortages, improve environmental conditions, and improve the utilization of biomass resources. Pyrolysis is the first step in the conversion process, which has an important influence on the subsequent transformation(such as gasification, liquefaction, burning and charring, etc.). So co-pyrolysis characteristics of coal and biomass is necessary to be figured out. Co-pyrolysis characteristics of coal and biomass were studied in a TGA and a fixed-bed reactor. The synergistic effect in co-pyrolysis experiments was investigated by comparing the product yields and distribution of gas, tar and char during pyrolysis of blends with those obtained during pyrolysis of individual fuels. The char, oil and gas were analyzed by Fourier transform infrared spectroscopy(FTIR), gas chromatography–mass spectrometry(GC–MS), and gas chromatography(GC), respectively.TGA experiments showed that biomass decomposition took place at lower temperatures compared to lignite. In fixed-bed experiments, the synergetic effect increased the yield of volatile matter compared to the calculated values. There seemed to be a shift of oil components towards the smaller molecular weight products.The major gases released at low temperatures were CO2 and CO. However, hydrogen was the primary gaseous product at higher temperatures. During co-pyrolysis, concentrations of benzene, naphthalene, and hydrocarbons in the tar decreased, accompanied by an increase in phenols and guaiacol concentrations. With increasing the temperature, the intensity of all adsorption bands decreased. The disappearance of structural features was related to release of volatile matter during pyrolysi and the decomposition of functional groups. Through the experiment discovered the ash content of coal and biomass have a significant impact on the co-pyrolysis, therefore removing ash pretreatment would have a good effect in the later work. And because the alkali metals and alkaline earth metal in coal and biomass has catalytic effect to co-pyrolysis. So on the basis of the removing ash, adding catalyst could increase the content of gas and tar composition.