Mckenzie Lachlan J, Tian Fu-Jun, Li Chun-Zhu
Department of Chemical Engineering, P.O. Box 36, Monash University, VIC 3800, Australia.
Environ Sci Technol. 2007 Aug 1;41(15):5505-9. doi: 10.1021/es0705691.
This study was conducted to investigate the formation and destruction of NH3 during the gasification of coal in atmospheres containing O2 and steam. A Victorian brown coal was gasified in a novel bench-scale fluidized-bed/ fixed-bed reactor at 800 degrees C in atmospheres containing 2000 ppm O2, 15% H2O, or 2000 ppm O2 + 15% H2O. A NH3 standard gas was also used to study the destruction of NH3 in the gas phase and through gas-solid interactions. Sand, char, and coal ash were all found to enhance the destruction of NH3. An atmosphere containing O2 alone does not favor the conversion of char-N into NH3 but favors the destruction of NH3 through various mechanisms. The introduction of H2O into the gasification system greatly favors the conversion of char-N into NH3 and inhibits the destruction of NH3. The formation and destruction of NH3 in an atmosphere containing 15% H20 was similar to that in an atmosphere containing 15% H20 and 2000 ppm 02, indicating the dominant effects of steam in the formation and destruction of NH3 in a gasifier.
本研究旨在调查在含有氧气和蒸汽的气氛中煤气化过程中氨的形成与分解情况。一种维多利亚褐煤在新型实验室规模的流化床/固定床反应器中于800摄氏度下，在含有2000 ppm氧气、15%水或2000 ppm氧气 + 15%水的气氛中进行气化。还使用了氨标准气体来研究气相中以及通过气固相互作用对氨的分解情况。发现沙子、焦炭和煤灰均能促进氨的分解。仅含氧气的气氛不利于煤焦氮转化为氨，但有利于通过各种机制分解氨。向气化系统中引入水极大地有利于煤焦氮转化为氨，并抑制氨的分解。在含有15%水的气氛中氨的形成与分解情况与在含有15%水和2000 ppm氧气的气氛中相似，这表明蒸汽在气化炉中氨的形成与分解过程中起主导作用。
