Influence Of Depositional Environments On Coal Pyrolysis And Slurryability

The depositional environments are the main cause of different reduction degree, and the reduction degree effect the coal property of our country. The influence of reduction degree on coal property were studied with the pyrolysis, coke gasification, coal tar.Through proximate analysis, element analysis, structural parameters of coal quality analysis and infrared spectrum, we studied the influence of reduction degree on coal property of our country. Compared with the strong reductive degree coal,the weak reductive degree coal has characters of lower H/C atom, higher aromaticity and oxygen-containing functional groups.The pyrolysis and gasification of three coal samples with the different coalification and five coal samples with the same coalification degree but different reduction degree were investigated by means of TG-DTG-DSC and continuity coal pyrolysis-gasification. Coats-Redfern integral method was used to obtain the kinetics of coal pyrolysis. The result shows that the third order chemical reaction model was adapt to the whole temperature range and the pyrolysis mechanism is similar. The activation energy of SF and SH are 43-54 KJ/mol, while the other three coals with stronger reduction degree are 76～103 KJ/mol. The weight-loss ratio, specific surface area and reactivity of coal tar all increase with the rising of final pyrolysis temperature and the decrease of reduction degree.Because of the different coal sample and the process of pyrolysis, the property of coal tar from weak reductive degree is different from the coal tar from stronger reductive degree flash pyrolysis, it has the characters of little TI and QI, lower H/C atom, higher phenol content. The result of GC-MS indicate that XJ2 and QHMJY have the different acid compound and neutral compound.The optimum condition of extracting phenol from the coal tar from strong reductive degree flash pyrolysis is as below:density of NaOH 15%, temperature 60℃, density of H2SO4 50%The coal samples with higher coalification and stronger reductive degree show better slurryability, the additives can highten the Zeta of these coal samples,but their ash fusion temperature are very high, the slurryability of weaker reductive degree can be enhanced and the ash fusion temperature of stronger reductive degree can reach the requirement of the gasification furnace.