碳酸盐岩干酪根催化降解生烃过程及动力学研究

A STUDY ON CHARACTERISTICS AND KINETICS OF CATALYTIC DEGRADATION FROM KEROGEN IN CARBONATE ROCKS

以甘肃平凉地区奥陶系碳酸盐岩干酪根为对象,利用热模拟实验方法和化工催化原理,从热解生烃组成特征、生烃量及生烃动力学等方面考察了不同介质对干酪根热解生烃过程的影响。结果表明,碳酸盐岩对干酪根生烃过程具有反催化作用,随着温度的增加,反催化作用越明显。膏岩CaSO4则表现出正催化作用,各种盐类对干酪根生烃过程影响较小。干酪根热解动力学研究表明,生烃动力学参数活化能E与视频率因子A之间不是独立变化的,它们之间存在一定的关系,即:E与lnA呈线形关系,这对于认识碳酸盐岩干酪根的化学结构及热解生烃机理具有一定的参考价值。

The effects of catalysts on hydrocarbon generation from kerogen, with the simulated samples being the Ordovician carbonate rocks from Pingliang area, Gansu province, NW China, were investigated by using simulation experiment and chemical catalysis mechanism. The catalytic action of different catalysts was studied on the product composition, hydrocarbon yield, kinetics of hydrocarbon generation, and so on. It is found that different catalysts might have different effects on hydrocarbon generation. In a situation of carbonate rocks existing, the yield of generated hydrocarbon S 2 decreased because of the adsorption of carbonate on pyrlysates. The insoluble salt, CaSO 4, as a catalyst, enhanced kerogen degradation to increase the yield of hydrocarbon (S 2). The soluble salts including CaCl 2 ,Na 2SO 4 and NaHCO 3 had few effects on the hydrocarbon generation from kerogen. As the kinetics was concerned, carbonate rocks had a negative catalytic effect and decreased the reaction rate, but CaSO 4 had a positive effect and gave rise to the reaction rate. In addition, it was also found that the kinetics parameters, apparent activation energy and frequency factor had a relationship with each other, which could be reasonably described by an exponential function.