EFFECT OF PROCESS VARIABLES IN CATALYTIC HYDROPYROLYSIS ON THE RELEASE OF COVALENTLY BOUND ALIPHATIC-HYDROCARBONS FROM SEDIMENTARY ORGANIC-MATTER

Hydropyrolysis has considerable promise for application as an analytic al tool for release. of biomarker hydrocarbons in high yields with min imal structural rearrangements. In this study, the effect of key react or variables on the product yield and distribution of alkanes obtained from temperature-programmed fixed-bed hydropyrolysis of a Tertiary oi l shale (Goynuk, NW Turkey, classified as a type I kerogen) and a Tert iary lignite (Hambach, Lower Rhine Basin, Germany) has been investigat ed. A combination of slow heating rate (5 degrees C/min), high hydroge n pressure (15 MPa), and use of a dispersed sulfided molybdenum cataly st represents the best regime for achieving high conversions to dichlo romethane-soluble oil while minimizing the structural rearrangement of biomarker species. Staged hydropyrolysis has confirmed that hopanes r eleased at higher temperatures through cleaving relatively strong bond s are quantitatively more significant than those released at lower tem peratures. These findings have reinforced the unique ability of hydrop yrolysis to maximize the yields of covalently bound alkanes while main taining the biologically inherited 17 beta(H),21 beta(H) stereochemist ries of the hopanes, largely intact, even for the lignite investigated .