固体热载体热解煤中氮的迁移特性

TRANSFORMATION OF NITROGEN DURING COAL PYROLYSIS WITH SOLID HEAT CARRIER

在固体热载体快速热解装置上考察了锅炉循环灰对内蒙古羊市塔烟煤热解过程中氮的迁移转化特性的影响.结果表明,在考察温度（530℃～660℃）内,在气相氮中仅含有HCN和NH3,无N2产生.循环灰对煤结构及焦油分子中氮杂环的裂解没有催化作用,与惰性石英砂作为热载体的实验结果相比,热解温度600℃时,循环灰作为热载体使气相中HCN-N和NH3-N的产率分别降低了24.53%和29.86%.并通过向惰性石英砂中添加碱性矿物质对循环灰中影响煤热解过程中气相氮释放的主要物质进行了考察.

In this paper, the fast pyrolysis of Inner Mongolia Yangshita bituminous coal with circulating ash as the solid heat carrier was carried out in a bench scale reactor, and the effects of the pyrolysis temperature on nitrogen distribution in products were investigated. The results showed that the nitrogen in coal was released into the gas phase only in the form of NH3 and HCN at the range of 530 ℃-660 ℃, and no N2 was detected. The circulating ashes had no obvious catalytic effects on the cracking of nitrogen heterocyclics in tar and char, but it could fix part of NH3 and HCN released during pyrolysis in ash. Comparing with the inert heat carrier, the yields of HCN-N and NHa-N decreased by 24.53% and 29.86% when the coal was pyrolyzed at 600 ℃using circulating ash as heat carrier. Furthermore, the main influencing factors in circu- lating ash were also investigated by adding the alkaline earth metals into the inert quartz sand.