Hydrous pyrolysis of four Argonne Premium coals.

摘要

Pretreatment experiments were done under hydrous pyrolysis conditions with four Argonne Premium coals (Zap lignite, Wyodak subbituminous, Illinois bituminous, Pittsburgh bituminous) over a range of temperatures (250--350(degrees)C) and pressures (1000 - 4000 psig). The residues from these experiments were further studied by programmed pyrolysis in a TG-FTIR system. The yields of pyrolysis tar were found to increase sharply at short pretreatment times (< 60 min at 350(degrees)C) and decline slowly at longer times. The yields of pyrolysis methane increase monotonically with pretreatment time, while the yields of pyrolysis CO(sub 2) decline monotonically. All of these trends are in agreement with the contention that hydrous pyrolysis is similar to an accelerated geological aging of the coal. The results for CO evolution were somewhat contrary in that there was usually an initial increase followed by a decline. It is believed that this CO results from decomposition of hydroxy and dihydroxy structures which are created by the hydrous pyrolysis process.