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US 5,296,133 AGranted
Low ash coal products from depolymerized coal
AssigneeExxon Research & Engineering Co.
InventorsGeorge M. Kramer, Daniel P. Leta, William A. Lamberti, Mark M. Disko, Sutinder K. Behal, Edwin R. Ernst
Life of this patent
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Abstract
A process for preparing a low ash coal wherein coal is depolymerized at low temperature by contacting finely divided coal with a hard acid and soft base, and extracting the depolymerized coal to remove mineral contaminants.
Claims8
A process for removing mineral contaminants from depolymerized coal which comprises:
- depolymerizing coal by mixing finely divided coal particles with a hard acid in the presence of a soft base at temperatures of from 0.degree. to 100.degree. C., said hard acid being characterized by a heat of reaction with dimethylsulfide of from 10 kcal/mol to 30 kcal/mol and said soft base being characterized by a heat of reaction with boron trifluoride of from 10 kcal/mol to 17 kcal/mol;
- extracting the depolymerized coal with a polar solvent to remove hard acid, soft base and a portion of the mineral contaminants;
- mixing the extracted coal with a swelling solvent having a density of from about 1.2 to about 2.6 g/ml whereby the extracted coal floats and the mineral contaminants sink;
- and
- separating the mineral contaminants from the extracted coal.
2 more elements
Dependencies are inferred from the claim text.