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U.S. Department of Energy
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Short contact time liquefaction of subbituminous coal

Technical Report ·
OSTI ID:6790034

This report describes a series of continuous unit studies determining how pyrite addition, as well as other variables (including solvent quality, slurry recycle, temperature, residence time), affect the short contact time liquefaction of subbituminous coal. Dissolution of low-rank coal is much more strongly affected by pyrite addition than by solvent quality. Mild hydrotreatment of an SRC I solvent provided a solvent which increased conversion only slightly over that achieved with the original SRC I solvent. Addition of pyrite or pyrrhotite, however, resulted in a significant improvement in conversion. The low quality solvent was SRC I solvent while the high quality solvent was from the Lummus Integrated Two-Stage Liquefaction Process. Essentially identical conversions were obtained with the high quality and low quality solvents. Pyrite brought about the same significant improvement in conversion in each of the solvents. Although use of a lower level of a higher quality catalyst (CoMo/Al/sub 2/O/sub 3/) increased hydrogenation and increased conversion of SRC to distillate more effectively than pyrite, the pyrite was more effective in decreasing the insoluble organic matter yield. Conversion was also increased by partial slurry recycle; i.e., by recycling a fraction of the dissolver effluent (containing SRC, insoluble organic matter and mineral matter) mixed with an equal amount of distillate in place of all distillate solvent of the normal short contact time SRC I process. Over the ranges investigated, conversions increased with increasing temperature or residence time. These increasing conversions were generally accompanied by increasing hydrogen consumption and/or hydrocarbon gas make.

Research Organization:
Gulf Research and Development Co., Shawnee Mission, KS (USA)
DOE Contract Number:
AC22-82PC50001
OSTI ID:
6790034
Report Number(s):
DOE/PC/50001-28; ON: DE85001160
Country of Publication:
United States
Language:
English