GEOCHEMICAL CHARACTERISTICS OF NEUTRAL BEARING-OXYGEN COMPOUNDS IN SOURCE ROCKS OF BIOGAS, BINBEI AREA, SONGLIAO BASIN
松辽盆地滨北地区生物气源岩中醇、酮含氧化合物的地球化学特征

Alcohol and ketane compounds are the intermediate products,which organic matter will have been transformed into biogas in the immature source materials.The abundance of neutral bearing-oxygen,especially,alcohol compounds are higher in source rocks from the Cretaceous system in the Binbei area, Songliao basin. It mainly includes normal monoalcohol from C_8(or C_9)to C_(32), the more samples are with C_(12) dominant position, and another samples are C_(17) or C_(18) as main peak.A series of ketane compounds is determined in some samples collected from the Binbei area.These compounds mainly contain 2-,3-,4-,5-,6-,7- chain ketanes and a isoprenoid-ketane, which has the highest peak.The content of the 2-ketane is more than 3-ketane or 4-ketane,with C_(13) to C_(31)carbon number.But C-5,C-6,C-7 alkyl ketane co-overflow.Those compounds could suggest the input of terrestrial higher plant and animal transformed by microbes.The relative contents of all alcohol and ketane compounds decrease with increasing of depth or oldening of age,meanwhile non-hydrocarbon also decrease, but saturated hydrocarbon increases.It is suggested that bearing-oxygen compounds in non hydrocarbon via biochemical reaction are transformed into saturated hydrocarbon,this offeres the significant evidences for the obvious modification of microbes in the diagenetic stage,and this is an essential prerequisite of biogas generation.