Catalytic Gasification Process with Recovery of Alkali Metal from Char
First Claim
1. A process for extracting and recovering alkali metal from a char, the char comprising (i) one or more soluble alkali metal compounds and (ii) insoluble matter comprising one or more insoluble alkali metal compounds, the process comprising the steps of:
- (a) providing a char at an elevated temperature ranging from 50°
C. to 600°
C.;
(b) quenching the char in an aqueous medium to fracture the char and form a quenched char slurry;
(c) separating the quenched char slurry into a first liquid stream and an insoluble matter stream, the first liquid stream comprising at least a portion of the soluble alkali metal compounds from the char, and the insoluble matter stream comprising residual soluble alkali metal compounds and a first insoluble matter comprising insoluble alkali metal compounds;
(d) recovering the first liquid stream;
(e) contacting the first insoluble matter with an alkali metal hydroxide and calcium oxide, calcium hydroxide, or both, under suitable pressure and temperature so as to convert at least a portion of the insoluble alkali metal compounds in the first insoluble matter to one or more soluble alkali metal compounds and produce a first leached slurry comprising soluble alkali metal compounds and a partially extracted insoluble matter, wherein the partially extracted insoluble matter comprises insoluble alkali metal compounds;
(f) contacting the first leached slurry with carbon dioxide under suitable pressure and temperature so to convert at least a portion of the insoluble alkali metal compounds in the partially extracted insoluble matter to one or more soluble alkali metal compounds and produce a second leached slurry comprising soluble alkali metal compounds and a residual insoluble matter;
(g) separating the second leached slurry into a second liquid stream and a residual insoluble matter stream, the second liquid stream comprising a predominant portion of the soluble alkali metal compounds from the second leached slurry, and the residual insoluble matter stream comprising residual soluble alkali metal compounds and residual insoluble alkali metal compounds;
(h) recovering the second liquid stream; and
(i) washing the residual insoluble matter stream to recover substantially all of the residual soluble alkali metal compounds in the residual insoluble matter stream as a first wash stream,wherein the quenching and contacting are performed in the substantial absence of gaseous oxygen.
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Accused Products
Abstract
Processes are described for the extraction and recovery of alkali metal from the char that results from catalytic gasification of a carbonaceous material. Among other steps, the processes of the invention include a hydrothermal leaching step in which a slurry of insoluble particulate comprising insoluble alkali metal compounds is treated with carbon dioxide and steam at elevated temperatures and pressures to effect the conversion of insoluble alkali metal compounds to soluble alkali metal compounds. Further, processes are described for the catalytic gasification of a carbonaceous material where a substantial portion of alkali metal is extracted and recovered from the char that results from the catalytic gasification process.
153 Citations
16 Claims
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1. A process for extracting and recovering alkali metal from a char, the char comprising (i) one or more soluble alkali metal compounds and (ii) insoluble matter comprising one or more insoluble alkali metal compounds, the process comprising the steps of:
-
(a) providing a char at an elevated temperature ranging from 50°
C. to 600°
C.;(b) quenching the char in an aqueous medium to fracture the char and form a quenched char slurry; (c) separating the quenched char slurry into a first liquid stream and an insoluble matter stream, the first liquid stream comprising at least a portion of the soluble alkali metal compounds from the char, and the insoluble matter stream comprising residual soluble alkali metal compounds and a first insoluble matter comprising insoluble alkali metal compounds; (d) recovering the first liquid stream; (e) contacting the first insoluble matter with an alkali metal hydroxide and calcium oxide, calcium hydroxide, or both, under suitable pressure and temperature so as to convert at least a portion of the insoluble alkali metal compounds in the first insoluble matter to one or more soluble alkali metal compounds and produce a first leached slurry comprising soluble alkali metal compounds and a partially extracted insoluble matter, wherein the partially extracted insoluble matter comprises insoluble alkali metal compounds; (f) contacting the first leached slurry with carbon dioxide under suitable pressure and temperature so to convert at least a portion of the insoluble alkali metal compounds in the partially extracted insoluble matter to one or more soluble alkali metal compounds and produce a second leached slurry comprising soluble alkali metal compounds and a residual insoluble matter; (g) separating the second leached slurry into a second liquid stream and a residual insoluble matter stream, the second liquid stream comprising a predominant portion of the soluble alkali metal compounds from the second leached slurry, and the residual insoluble matter stream comprising residual soluble alkali metal compounds and residual insoluble alkali metal compounds; (h) recovering the second liquid stream; and (i) washing the residual insoluble matter stream to recover substantially all of the residual soluble alkali metal compounds in the residual insoluble matter stream as a first wash stream, wherein the quenching and contacting are performed in the substantial absence of gaseous oxygen. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16)
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Specification