MoS2在低熟有机质热演化生烃中的催化作用

MoS₂常用作有机质催化加氢热解的高效催化剂，通过活化流动相的高压H₂来提高热解产物的产率。但是MoS₂催化剂是否对有机质自身热演化生烃有影响却少有研究。为此，通过对低成熟Alum页岩干酪根及添加MoS₂催化剂的干酪根进行热模拟生烃对比实验，探究了MoS₂对干酪根热演化生烃的影响。实验结果表明MoS₂的加入使低熟干酪根具有更高的成烃潜力：(1)使轻烃(C_6-14)峰值产率增加且峰值温度前移24℃，但重烃(C₁₄₊)峰值产率显著降低，表明MoS₂加速了重烃向轻烃的热裂解转化；(2)使湿气产率在峰值温度(456℃)前轻微增加，但峰值温度后明显降低，表明MoS₂促进了湿气的生成及后期的裂解；(3)使甲烷(C₁)产率明显增加，特别是在528℃后C₁增加了近50%，这可能是因为MoS₂促进了高-过成熟阶段干酪根的加...

Catalytic role of MoS2 in hydrocarbon generation during thermal evolution of low-maturity kerogen

MoS₂ has been commonly used as an efficient catalyst for the kerogen hydropyrolysis to improve the yield with activated high-pressure and mobile phase of H₂. However， there is little document on whether MoS₂ has a certain effect on the thermal maturation of organic matter and hydrocarbon generation. In this study， the effects of MoS₂ on the thermal evolution of organic matter and hydrocarbon generation are investigated by comparative thermal simulation experiments on kerogen of low maturity from the Alum Shale with and without MoS₂ added. The results show that low-mature kerogen has greater potential for hydrocarbon generation in presence of MoS₂. MoS₂ acts to increase the peak yield of light hydrocarbons （C_6-14）， while decrease the peak yield of heavy hydrocarbons （C₁₄₊）， and lowering the temperature of peak hydrocarbon generation by about 24 ℃ at the same time， indicating that MoS₂ serves to accelerate the thermal cracking of heavy hydrocarbons to light hydrocarbons. The adding of MoS₂ also can slightly increase the yield of wet gases （C_2-5） before the peak hydrocarbon generation temperature （456 ℃） is reached， but significantly decrease it after the temperature surpasses its peak hydrocarbon generation value， indicating that MoS₂ can promote the generation and later cracking of wet gases. In addition， the existence of MoS₂ also remarkably raise the yield of methane （C₁）， especially at a temperature higher than 528 ℃ when the methane yield increases by nearly 50 %， a possible result of MoS₂ promoting the hydrogenation of kerogen at the high-to-over-mature stage. The difference of catalytic effect between pyrite （FeS₂） and MoS₂ is systematically compared， which is mainly controlled by the structure， stability and sulfur activity of catalysts.