高硫煤镜质组热解过程中结构变化及有机硫形态变迁规律研究

用手选富集与离心分离相结合的方法，从两种全硫含量相近的新西兰煤（NXL；S_t，ad=1.84%）和山西煤（SX；S_t，ad=1.80%）中分离出高纯度镜质组。在高纯Ar气氛下，分别制备了300、500、700和1 000 ℃下的镜质组焦。用FT-IR研究了两种镜质组中的脂肪氢、芳香氢随温度的变化，结果表明，SX镜质组中脂肪氢的相对含量较高，在热解过程中活性高于同温度下的NXL镜质组；两种镜质组中的脂肪氢相对含量都随温度升高而降低，温度高于500 ℃时，SX镜质组中脂肪氢相对含量基本不变，当温度高于700 ℃时，NXL镜质组中的脂肪氢相对含量基本保持不变；热解过程芳香氢都表现出先增大后减小的趋势。用XPS研究了镜质组中的有机硫含量及形态随温度的变化，结果表明，SX镜质组中易分解的有机硫化物较多，在300 ℃以下即可分解完全；NXL镜质组中的有机硫化物分解完全在700 ℃左右，两种镜质组中的噻吩类硫的含量都随热解温度的升高而增加，砜类硫的含量随热解温度的升高而降低。

Structure change and organic sulfur forms transformation during pyrolysis of high-sulfur vitrinite

High purity vitrinite was separated and concentrated from New Zealand(NXL; S_t,ad=1.84%) and Shanxi(SX; S_t,ad=1.80%) coal which have similar sulfur content. The vitrinite was pyrolyzed in a tube furnace reactor under argon at 300, 500, 700 and 1 000 ℃. The effect of temperature on the functional group content and organic sulfur forms transformation was examined by Fourier transform infrared spectrum and X-ray photoelectron spectrum, respectively. The FT-IR experiments show that aliphatic hydrogen content in SX vitrinite and its reactivity is higher than those of NXL vitrinite at same temperature. The aliphatic hydrogen in both vitrinites decreases with increasing temperature. The aliphatic hydrogen content in SX and NXL vitrinite is unchanged when the temperature is above 500 and 700 ℃, respectively. The aromatic hydrogen increases first and then decreases with increasing temperature. The XPS results show that the organic sulphide, which is more thermal unstable, is richer on surface of SX vitrinite than that of NXL. It is decomposed completely below 300 and 700 ℃ for SX and NXL, respectively. The content of thiophenic compounds increases with increasing temperature, but that of sulfones compounds is just the reverse.