Release of alkanes from sedimentary organic matter via sequential degradation involving catalytic hydropyrolysis

Conference · Tue Dec 31 04:00:00 EST 1996

OSTI ID:539007

Love, G D; McAulay, A; Snape, C E ^[1]

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1. Univ. of Strathclyde, Glasgow (United Kingdom)

Fixed-bed pyrolysis of petroleum source rocks (type I and II kerogens) and high-volatile coals (type III ketogens) at high hydrogen pressures (> 10 MN, hydropyrolysis) in the presence of a dispersed sulphided molydenum catalyst gives rise to extremely high oil (dichloromethane-soluble) yields (>60%) with overall conversions of the organic matter being greater than 90%. The yields and conformations of the hopanes and steranes released from a selection of petroleum source rocks and coals by sequential dichloromethane and pyridine extraction, catalytic hydrogenation and hydropyrolysis will be presented, together with the influence of hydrogen pressure and heating rate on alkane yields and sterochemistry. The aim of the hydrogenation step (conducted at 300{degrees}C cf. 520{degrees}C for hydropyrolysis) in this sequential degradation scheme is to cleave only the weaker covalent bonds. The findings have demonstrated the unique ability of hydropyrolysis to mainline the yields of covalently-bound alkanes while maintaining the biologically-inherited 17{beta}(H), 21{beta}(H) stereochemistries of the hopanes, largely intact, even for coals. The total alkane yields from hydropyrolysis represented ca 30% w/w of the organic matter remaining in immature type I kerogens with yields of the C{sub 29}-C{sub 35} 17{beta}(H), 21{beta}(H) hopanes being much higher than from both normal pyrolysis and the hydrogenation step.

• OSTI ID: 539007
• Report Number(s): CONF-960807--
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
04 OIL SHALES AND TAR SANDS
ALKANES
CATALYTIC EFFECTS
COAL
DECOMPOSITION
EXTRACTION
HYDROGENATION
KEROGEN
MOLYBDENUM
ORGANIC MATTER
PETROLEUM
PYROLYSIS
SOURCE ROCKS
YIELDS