Kerogen Chemistry. 8. Hydrous Pyrolysis of Rundle Kerogen: Source of the Oxygen in CO_2 and Mineral Catalysis

摘要

Rundle shale and rundle kerogen were reacted under hydrous pyrolysis conditions and the formed amounts of CO_2 and carboxylic acids were measured. The amount of CO_2 formed from kerogen when the shale is reacted exceeds that formed when the isolated kerogen is reacted, demonstrating involvement of the mineral phase in the reaction. The chemical composition of the kerogen is known from Siskin's work. It is possible that the CO_2 formed during the reaction of kerogen (no mineral except pyrite) at 325℃ comes entirely from the kerogen. This is not true when the shale is reacted. For the reaction of kerogen at 350℃, it is unlikely that all of the oxygen in the CO_2 and carboxylic acid products is derived from the kerogen. When the kerogen was further demineralized with CrCl_2, the amount of CO_2 formed decreased. When a mixture of FeS, FeS_2, and Fe_2O_3 was added to the kerogen, CO_2 formation increased. Minerals play a role in hydrous pyrolysis reactions. It cannot be decided from these data whether this role is catalytic or direct involvement as a redox buffer.