Influence of temperature and Ca(OH)2 on releasing tar and coal gas during lignite coal pyrolysis and char gasification

The yield of tar and syngas has been investigated by catalytic pyrolysis of Pingzhuang lignite (PZL) over Ca(OH)(2) catalyst in temperature range of 600 degrees C-1000 degrees C in a tube furnace. The results show that the yield of volatile pyrolysis increases and char decreases with rising temperature for both raw and catalyzed Pingzhuang lignite. The hydrogen fraction (H-2) increased from 20% to 40% for the PZL sample: but, for the PZL-Ca(OH)(2) sample. H-2 fraction fluctuated randomly between 35% to 42%, with the maximum H-2 fraction found at 1000 degrees C. The Gas-chromatography mass-spectroscopic (GC-MS) analysis revealed that the maximum tar yield at 800 degrees C and 700 degrees C was obtained for PZL and PZL-Ca(OH)(2), respectively. The surface morphology of PZL and PZL-Ca(OH)(2) chars underwent different transformation in the presence of catalyst as illustrated by SEM/EDX, FTIR, and BET analysis. Furthermore, char sample was investigated for the carbon conversion and reactivity index using TGA analysis under N-2 and CO atmosphere. (C) 2019 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights reserved.