油气形成过程中一个最明显的氧化还原反应实例——胡萝卜烷的形成

An Obvious Example of Redox Reaction in the Process of Oil and Gas Generation-the formation of carotane

人所熟知的胡萝卜烷由胡萝卜素加氢构成,在转化中需要消耗大量的氢,因而整个过程是非常典型的氧化还原反应。模拟实验揭示:胡萝卜烷的形成需要充足的还原剂;即使环境并非属于氧化,如果缺乏还原剂,胡萝卜素也不能转化成胡萝卜烷;含有饱和环的甾萜类是良好的还原剂。在有机质成烃过程中自始至终都有氢或氧等杂原子的加入与脱除,因此氧化还原反应贯穿于成烃的全过程。在很多情况下自身很容易遭受氧化的胡萝卜素居然能够在某些环境中成为氧化剂,那么有机酸、醇、酮等非烃可以还原转化成烃就更不应质疑了。

In the whole process of forming hydrocarbon, there exist the joining and removal of hydrogen or oxygen atom and heteroatom from the beginning to end. Therefore, redox reaction takes place in the whole process. The formation of carotane is the result of the hydrogen addition of carotene, and this process is very typical redox reaction, which needs plenty of hydrogen. Through the pyrolysis experiments, it is discovered that the carotane formation demands ample reductant. If absent, even the environment does not belong to oxidation environment, the carotene also can not form carotane. Saturated cyclic steroid and terpenoid compound is the better reductant. Carotane has the very close relation with cricoids biomarkers. Therefore, we can affirm that saturated cyclic steroid and terpenoid compound is the reductant in the formation process of the carotane. Actually, the carotene which can be oxidized very easily to be the oxidant in some environments. So, organic acid, alcohol and ketone etc. , can be reduced and form hydrocarbon, which should not be problematic.