摘要
针对 3种不同煤阶的高硫煤 ,分别在固定床反应器中考察其固定升温速率下原煤热解和半焦在不同温度下的水蒸气部分气化过程中的硫变迁行为 .研究过程分为热解和部分气化 2个子过程 .结果表明 ,热解过程中大同、义马和西山煤总脱硫率分别为 41 %、42 5 %和 2 3 1 % ,其过程中FeS2 完全转化为FeS ,不稳定的有机硫部分析出 ,硫从固相中的脱除大于碳的转化 ,硫在气相中得到富集 ;在部分气化过程中 ,对于大同和西山煤 ,半焦中硫含量可有效降低 ,脱硫率分别提高 2 6 47%和 1 9 3 7% ,其中无机硫化物 (FeS)易于气化析出 ,其析出程度随温度升高而增大 .但对义马煤焦部分气化结果证实 :在 70 0℃气化时 ,总脱硫率可提高 2 4 60 % ,在高于 70 0℃气化时 ,有利于碱土金属与H2 S反应进行 ,同时由于碳骨架的气化速度加快 ,降低了其有机质对灰分固硫行为的传质阻力 ,所以灰分中碱土金属的固硫作用增强 ,使得半焦中硫含量增加 ,脱硫率与碳转化率的差值下降 。
The development of various process to the pre desulfurization of coal was drawn more attention. In present study, the transformation of sulfur forms of three different ranks high sulfur coals during coal pyrolysis and partial gasification were investigated in a fixed bed reactor. The sulfur and carbon content analysis of original coal and coal char produced were determined by LECO SC 444 and wet chemical analysis according to Sugawara's method. The results showed that half of inorganic sulfur and partial of organic sulfur were removed during coal pyrolysis. And the sulfur removal was much more than carbon during pyrolysis process; and the sulfur in the coal char, especially the sulfide sulfur was removed completely during partial gasification process for both Datong coal and Xishan coal, the degree of sulfide sulfur removal could be increased with increasing temperature. At the same time, the results of Yima coal showed that the effect of fixed sulfur by alkaline metals increased when the temperature was higher than 700℃, which attribute to the increase of the fixed sulfur reaction rate and the decrease of mass transfer limitation.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2003年第2期60-65,共6页
Environmental Science
基金
国家重点基础研究发展规划项目 (G19990 2 2 10 5 )
关键词
煤热解
预脱硫
部分气化
形态硫
coal pyrolysis
pre desulfurization
partial gasification
sulfur forms
