轻烃的吸附与解吸模型

THE MODEL OF LIGHT HYDROCARBONS ADSOPTION & DESORPTION

轻烃具有以自由基进行反应的特性,烯烃的双键易断裂。阐述了沉积岩表面吸附轻烃时遵循固体表面吸附的理论:首先是物理吸附,随着分子距离的减小,范德华引力增大,增大到一定程度就可以使烷烃中被物理吸附的C-H键生成C.和H.,使烯烃中被物理吸附的C=C键生成.C-C.、.C-C.或C.和H.并分别和表面的分子或离子生成新的化学键;此时,吸附变为化学吸附,化学吸附轻烃的热解吸是以自由基形式进行,在较低温度下的解吸是化学吸附的可逆过程,在较高温度下的解吸则发生组分的化学重组反应,而常温酸解吸是化学吸附的可逆过程,不发生化学重组反应。指出轻烃的吸附与解吸有较多的实验证据,研究轻烃的吸附与解吸模型对轻烃分析技术发展有重要指导意义。

Light hydrocarbons can react by the means of free radicals. The double bonds of alkenes are easy to rupture. There is surplus bond force in solid surface, which can adsorb light hydrocarbons. When the sediment surfaces adsorb light hydrocarbons, it follows the theory of solid surface adsorption. Firstly, light hydrocarbons adsorbed physically, the molecule interval minish and the Vandwa force augment. Then the adsorbed bond C-H of alkyl hydrocarbons turn into C · and H· ,and the adsorbed bond C=C turn into · C-C · , · C-C · or C· and H· respectively react with the molecule or ion of the surface. At this time the adsorption become chemical adsorption. The thermo-desorption carry through free radicals： desorption at low temperature is a reversible course, desorption at high temperature will occur regroup chemical reaction. But acid-desorption at normal temperature is a reversible course without regroup chemical reaction. There are lots of experiment evidence on the model of light hydrocarbs adsorption and desorp- tion. Researching the model can instruct the development of the technology.