High temperature simulation of petroleum formation—III. Effect of organic starting material structure on hydrocarbon formation

Abstract

The importance of the structure of organic matter used as a precursor in petroleum formation has been investigated by high temperature simulation reactions. The products of pyrolysis reactions of lignin, cellulose, protein and lipids have been compared on the basis of the yield and composition of the gaseous and liquid products. Each organic matter type was also investigated with a carbonate, water, and ammonia reaction. Lignin and cellulose are poor sources of liquid hydrocarbons, but cellulose in the presence of carbonate gives a high yield of gaseous hydrocarbons. Protein pyrolysis gives a high oil yield with an alkane distribution similar to petroleum. The presence of carbonate increases the yield of all liquid compound classes. The gas yield from protein is also raised by the presence of carbonate. The lipids produced the highest oil yield of the substances tested but the n-alkanes show an odd carbon length predominance unlike the distribution found in petroleum. The results indicate that fatty acids must undergo alteration during kerogen formation sufficient to remove the odd carbon chain length bias and that the alkyl groups of protein may be an important source material for alkane formation.