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US 4,285,140 AGranted
Dewatering and upgrading low rank coal by a two-step hydrothermal treatment
AssigneeShell Oil Company
InventorsLeopold van Raam, Herman P. Ruyter, Josefus W. van Breugel
Life of this patent
Estimating the term…
Abstract
Low rank coal is dewatered and upgraded by heating a coal/water mixture at 150.degree. to 300.degree. C. at a pressure preventing water vaporization, mechanically separating the water, then heating the coal at 300.degree. to 400.degree. C. at a pressure allowing water vaporization.
Claims4
A process for dewatering and upgrading low rank coal or other carbonaceous material comprising:
- heating a mixture of the coal and a substantially equal weight of free water to a temperature of from about 150.degree. to 300.degree. C. while maintaining a pressure which substantially prevents the vaporization of water;
- mechanically separating substantially all of the water from the mixture;
- and
- heating the so-separated coal for from about 5 minutes to 5 hours at a temperature of from about 300.degree. to 400.degree. C., which temperature exceeds the temperature used in the prior heating step, is applied at a pressure which at least substantially equals the pressure used in the prior heating step and is a pressure at which water is vaporized so that the water content of the coal is reduced to less than about 10% by weight and the coal is significantly upgraded by decarboxylation without significant gasification.
1 more element
A process for dewatering and upgrading low rank coal or other carbonaceous material comprising:
- heating a mixture of the coal and a substantially equal weight of free water to a temperature of from about 150.degree. to 300.degree. C. while maintaining a pressure which substantially prevents the vaporization of water;
- compressing the so-heated coal into tablets having maximum diameters of from about 5 to 100 mm;
- mechanically separating substantially all of the water from the mixture;
- heating the so-separated coal for from about 5 minutes to 5 hours at a temperature of from about 300.degree. to 400.degree. C. and a pressure at which water is vaporized so that the water content of the coal is reduced to less than about 10% by weight and the coal is significantly upgraded by decarboxylation without significant gasification.
1 more element
Dependencies are inferred from the claim text.