Pyrolysis-Gas Chromatography of the Oil Shale in Lucaogou Formation, Dahuangshan, Southern Junggar Basin
摘要
///Dahuangshan oil shale mine is located at the main position of oil shale deposit belt in Northern Bogda Mountain. The majority of the pyrolysis products of Dahuangshan oil shale are n-alkanes and n-alkenes, which approximately account for 90% of total products. Aliphatic groups break from kerogen nuclear when heated and turn into alkyl radicals. Alkyl radicals, which are very active, quickly turn into n-alkanes or n-alkenes depending on capturing or losing hydrogen radicals. Due to the effect of space steric hindrance, the formation of n-alkenes need more energy than n-alkanes, and the formation ratio of short chain n-alkenes (C14-) is bigger than long chain n-alkenes (C15+). The relative contents of C1—C4 n-alkanes and n-alkenes, C5—C14 n-alkanes and n-alkenes, and C15+ n-alkanes and n-alkenes are effective parameters to distinguish kerogen type,as proved. Also the composition ratio of all n-alkanes and all n-alkenes is also an accurate parameter, for the type -Ⅰ kerogen is below 2.17 while the type-Ⅱ is above it.