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U.S. Department of Energy
Office of Scientific and Technical Information

CO.sub.2 Pretreatment prevents calcium carbonate formation

Patent ·
OSTI ID:863593
Scale formation during the liquefaction of lower ranking coals and similar carbonaceous materials is significantly reduced and/or prevented by pretreatment with carbon dioxide. The carbon dioxide pretreatment is believed to convert the scale-forming components to the corresponding carbonate prior to liquefaction. The pretreatment is accomplished at a total pressure within the range from about 14 to about 68 atmospheres and a carbon dioxide partial pressure within the range from about 14 to about 34 atmospheres. Temperature during pretreatment will generally be within the range from about 100.degree. to about 200.degree. C.
Assignee:
Exxon Research & Engineering Co. (Florham Park, NJ)
Patent Number(s):
US 4206033
OSTI ID:
863593
Country of Publication:
United States
Language:
English