Pyrolysis And Hydropyrolysis Of Weak Reductive Coals

Pyrolysis and hydropyrolysis of three weak reductive coals were carried out to investigate the effects of temperature and heating rate on pyrolysis performance. Main research work and results as following:Firstly, the pyrolysis characteristics of three typical weak reductive coals (Shendong, Lingwu and Hami) and one typical reductive coal (Pingshuo) and their macerals were studied by thermogravimetric analyzer. The results showed that the peaks of DTG curves become smaller and shift to higher temperature region with increase of inertinite content in the coal samples. The final weight loss of weak reductive coal presents a decreasing trend and the DTG curve shifts to higher temperature region with increase of heating rate.Secondly, the effect of temperature on product distribution was further studied in a fixed bed reactor at N₂ atmosphere. The results indicated that the tar yields of weak reductive coals are lower than that of Pingshuo coal at the same temperature. The tar yields of Pingshuo coal and Shendong coal increase with increasing temperature, and decrease after temperature more than 650℃. The largest tar yield of Pingshuo and Shendong coal is 17.1 wt.ï¼…daf and 14.4 wt.ï¼…daf, respectively. The tar yield of Lingwu and Hami coal have little decreasing trend. The gas yields of the four coals increase and the char yields decrease with the increasing of temperature.Finally, the effect of temperature on product distribution was also studied in a fixed bed reactor at H₂ atmosphere. The results showed that the tar and gas yields of weak reductive coals increase, but the char yields decrease with increasing temperature. For Pingshuo coal, the largest tar yield reaches 19.8 wt.ï¼…daf at 650℃, and gas yield increases but char yield decreases with increase of temperature.