Experimental Investigation on Hydrothermal Reduction of Sulfates to H2S and Organic Sulfides by Ethene
Experimental Investigation on Hydrothermal Reduction of Sulfates to H2S and Organic Sulfides by Ethene
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DOI：
10.4236/ojogas.2020.54015
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发表时间：
2020-07
期刊：
影响因子：
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通讯作者：
H. Chao;Ding Kangle;Yan Liu;Fujia Guan;Zou Mei;Zhenzhen Yu;Yi Wu
中科院分区：
文献类型：
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作者：
H. Chao;Ding Kangle;Yan Liu;Fujia Guan;Zou Mei;Zhenzhen Yu;Yi Wu
烯烃参与硫酸盐热化学还原（TSR）的动力学特征在地质文献中从未报道过。本研究对热液条件下乙烯的TSR进行了约束模拟实验。典型的TSR产物包括H2S、CO2、硫醇、硫化物、噻吩衍生物和苯并噻吩。乙烯对TSR的表观活化能E和表观频率因子A分别为76.370 kJ/mol和4.579 s-1。根据热力学分析，乙烯参与TSR反应的活化能较乙烷低，表明乙烯的反应活性远高于乙烷。通过一级动力学外推，实验确定了速率常数，在深埋成岩环境（120°C - 180°C）下，MgSO4的半衰期为67.329 ~ 3.053年。这些数值表明，在高温气藏（120°C - 180°C）中，乙烯对TSR的反应速度非常快。因此，天然气和/或石油热裂解和TSR蚀变形成的新乙烯不能在TSR过程中存活，在TSR天然储层中很少被检测到。
The kinetic characteristics of alkenes involved in thermochemical sulfate reduction (TSR) have been never reported in geological literature. In this study, TSR by ethene under hydrothermal conditions was performed in the constrained simulation experiments. Typical TSR products consisted of H2S, CO2, mercaptans, sulfides, thiophenes derivatives and benzothiophene. The apparent activation energy E and apparent frequency factor A for TSR by ethene were determined as 76.370 kJ/mol and 4.579 s-1, respectively. The lower activation energy for ethene involved in TSR relative to ethane suggested that the reactivity of ethene is much higher than that of ethane, in accordance with the thermodynamic analysis. Rate constants were determined experimentally using first-order kinetics extrapolate to MgSO4 half-lives of 67.329 years - 3.053 years in deep burial diagenetic settings (120°C - 180°C). These values demonstrate that the reaction rate for TSR by ethene is extraordinarily fast in high-temperature gas reservoirs (120°C - 180°C). Consequently, the newly formed ethene from thermal cracking and TSR alteration of natural gas and/or petroleum could not survive after TSR process and were rarely detected in natural TSR reservoirs.