CO_2气氛对煤热解过程中硫逸出的影响

采用热解-质谱(Py-MS)与热解-气相色谱(Py-GC)相结合的方法对平朔(PS)和义马(YM)原煤、脱灰煤及其脱黄铁矿煤进行了热解实验,考察了CO_2气氛对煤热解过程中硫逸出行为的影响。并采用质谱在线分析H_2S、COS和SO_2的逸出曲线,利用气相色谱分析H_2S、COS和SO_2在气相中的逸出量。结果表明,CO_2气氛有利于H_2S、COS和SO_2进入气相,且逸出量增加,而COS增加幅度更大。同时,CO_2气氛有利于H_2S和SO_2最大逸出峰温提前。另外,CO_2气氛对原煤的H_2S、COS和SO_2逸出温度影响较大,但对脱灰煤的影响较小。在较高的温度下,CO_2有利于煤中稳定有机硫的分解。这进一步验证了在较高温度下COS形成与CO相关,而在较低温度下与CO无关。

Effect of CO2 atmosphere on sulfur release during coal pyrolysis

Yima (YM) coal and Pingshuo (PS) coal as well as their deashed coals and depyrited coals were used to investigate the effects of CO₂ and Ar on the sulfur release behavior during coal pyrolysis by pyrolysis connected with mass spectrometer (Py-MS) and pyrolysis connected with gas chromatogram (Py-GC). It is found that CO₂ atmosphere can promote the release of H₂S, COS and SO₂, especially the remarkable releasing of COS. In addition, CO₂ atmosphere can decrease the maximum release peak temperature of H₂S, COS and SO₂ for raw coals, while there is no obvious effect for their deashed coals. At the same time, CO₂ is beneficial to the decomposition of organic sulfur at higher temperature. That the COS formation is related to CO at higher temperatures and has nothing to do with CO at lower temperatures is validated.