高纯气体乙烷及丙烷裂解的动力学研究

Study on kinetics of high-purity ethane and propane cracking

王英超 靳永斌 税蕾蕾 黄合庭 程子翔 王长江

1．中海油能源发展钻采工程研究院湛江实验中心，广东 湛江 524057 中国科学院南海海洋研究所，广东 广州 510301 中国科学院广州地球化学研究所，广东 广州 510640 中国石油大学（北京）地球科学学院，北京 102249 中国石油集团测井有限公司油气评价中心，陕西 西安 710077

为了探讨烃类气体的生烃动力学与碳同位素动力学的反应机理，为油气勘探的动力学研究提供准确、可靠的依据，在实验室条件下，利用先进的金管高压封闭体系方法，开展高纯乙烷（C2H6）和丙烷（C3H8）气体恒压条件下的热模拟实验，对不同时间点生成的气体进行了组分、碳同位素定量测试。实验结果表明，甲烷的产率随着温度上升不断增加，且在520 ℃后表现出快速增加趋势，丁烷与戊烷在520 ℃表现为最高值；高纯乙烷和丙烷样品的碳同位素具有随温度升高而变重的趋势。研究认为，高纯气体样品在恒压热模拟过程中裂解与聚合反应同时发生，且总体上分子量大的化合物比分子量小的稳定性差, 各化合物的异构体的绝对量相对于正构体比例很小。

Accurate acquirement of precise reaction mechanism of hydrocarbon generation kinetics and carbon isotope kinetics for gaseous hydrocarbon can afford the exact dependable data for kinetics study of petroleum exploration. Pyrolysis simulated experiment with constant pressure has been performed on high-purity ethane(C₂H₆) and propane(C₃H₈) using the gold tube close system under laboratory conditions, and the gas generated at different periods was analyzed on quantitative test of composition and carbon isotope. The results of experimental study demonstrated that methane production increases along with temperature, and shows the rapid increase after 520 ℃, butane and pentane reach a peak value at 520 ℃; carbon isotope fractionation was distinct and obvious on high-purity ethane and propane samples. Study results show that the cracking and polymerization reaction were simultaneous in high-purity gas samples during pyrolysis simulated experiment, compound with large molecular weight presents a poorer stability than the compound with small molecular weight. Absolute magnitude proportion of isomer is smaller than that of normal paraffin hydrocarbons in different compounds.

10.6056/dkyqt201303010