Department of Chemical Engineering, Monash University, Victoria 3800, Australia.
Environ Sci Technol. 2010 May 15;44(10):3719-23. doi: 10.1021/es1001538.
Understanding the conversion of coal-N during gasification is an important part of the development of gasification-based power generation technologies to reduce NO(x) emissions from coal utilization. This study investigated the conversion of coal-N in the presence of NO during the gasification of three rank-ordered coals and their chars in steam and low-concentration O(2). Our results show that NO can be incorporated into the char structure during gasification. The inherent char-N and the N incorporated into the char from NO-char reactions behave very similarly during gasification. During the gasification in steam, significant amounts of HCN and NH(3) can be formed from the incorporated N structure in char, especially for the relatively "aged" chars, mainly due to the availability of abundant H radicals on the char surface during the gasification in steam. During the gasification in 2000 ppm O(2), the formation of HCN or NH(3) from the N structures in char, including those incorporated into the char from the NO-char reactions, was not a favored route of reaction mainly due to the lack of H on char surface in the presence of O(2).
了解煤气化过程中煤氮的转化对于开发基于煤气化的发电技术以减少煤利用过程中氮氧化物的排放是非常重要的。本研究考察了在蒸汽和低浓度 O(2)中气化三种分级煤及其煤焦过程中存在的 NO 时煤氮的转化。结果表明，NO 可以在气化过程中掺入煤焦结构中。固有的煤焦氮和由 NO-煤焦反应引入到煤焦中的氮在气化过程中表现出非常相似的行为。在蒸汽气化过程中，大量的 HCN 和 NH(3)可以由煤焦中掺入的 N 结构形成，特别是对于相对“老化”的煤焦，主要是由于在蒸汽气化过程中煤焦表面存在丰富的 H 自由基。在 2000 ppm O(2)的气化过程中，来自煤焦中 N 结构的 HCN 或 NH(3)的形成，包括由 NO-煤焦反应引入到煤焦中的 N 结构，不是一个有利的反应途径，主要是由于在 O(2)存在的情况下，煤焦表面缺乏 H。
