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US 4,857,077 AGranted
Process for removing flyslag from gas
AssigneeShell Oil Company
InventorMichael W. Potter
Life of this patent
Estimating the term…
Abstract
A process for the treatment of flyslag from the gasification of coal is described, the process being characterized, in one embodiment, by mixing of the flyslag with a cementitious material, a composition capable of converting sulfides in the flyslag at least to sulfur, and an aqueous waste stream from the gasification of coal, in specified proportions. A composition comprising flyslag, a cementitious material, and a composition capable of converting sulfides in the flyslag at least to sulfur, is also disclosed.
Claims9
A process for removing flyslag from a synthesis gas stream from which the bulk of the flyslag has already been removed comprising
- (a) passing said gas stream to a scrubbing zone which includes a loaded scrubbing solution stripping section, and scrubbing said gas stream with an effective amount of an aqueous scrubbing solution, and removing remaining flyslag particles and HCN, NH.sub.3, and COS from said gas stream, producing a partially purified gas stream substantially free of flyslag, and an aqueous stream containing flyslag particles from said stripping section, and passing said aqueous stream to a concentrating zone;
- (b) removing from said concentrating zone a concentrated aqueous stream derived from said aqueous stream and having a ratio of flyslag particulate solids to liquid greater than that of the aqueous stream entering said concentrating zone;
- (c) mixing a major portion of flyslag having sulfides present therein, a minor portion of cementitious material and an effective amount of a composition capable of converting sulfides in said flyslag at least to sulfur, with at least a portion of the concentrated aqueous stream from step (b), the concentrated aqueous stream being supplied in a ratio of from about one part to about five parts concentrated aqueous stream per part, by weight, combined total solids of flyslag and cementitious material, and producing a solid flyslag composite having improved disposal properties.
A process for the removal of flyslag from a gas stream containing flyslag, the flyslag having sulfides present therein and the gas stream derived from the gasification of coal, comprising
- (a) passing said gas stream containing said flyslag to a solids separation zone, and separating the bulk of the flyslag in said zone, producing solid flyslag and a gas stream having reduced flyslag content;
- (b) passing gas stream having reduced flyslag content from step (a) to a scrubbing zone which includes a loaded scrubbing solution stripping section, and scrubbing said gas stream with an effective amount of an aqueous scrubbing solution, and removing HCN, NH.sub.3, and COS and remaining flyslag particles from said gas stream, producing a partially purified gas stream substantially free of flyslag, and an aqueous stream containing flyslag particles from said stripping section, and passing said aqueous stream to a concentrating zone;
- (c) removing from said concentrating zone a concentrated aqueous stream derived from said aqueous stream and having a ratio of flyslag particulate solids to liquid greater than that of the aqueous stream entering said concentrating zone;
- (d) mixing a major portion of flyslag from step (a) and a minor portion of cementitious material and an effective amount of a composition capable of converting sulfides in said flyslag at least to sulfur, with at least a portion of the concentrated stream from step (c), the concentrated aqueous stream being supplied in a ratio of from about one part to about five parts concentrated aqueous stream per part, by weight, combined total solids of flyslag and cementitious material;
- and producing a solid flyslag composite having improved disposal properties.
2 more elements
A process for the gasification of coal comprising
- (a) partially combusting particulate coal in a gasification zone comprising at least one gasification reactor, and producing a hot gaseous stream containing synthesis gas, flyslag having sulfides present therein, and minor amounts of HCN, NH.sub.3, and COS;
- (b) quenching and cooling said hot gaseous stream, and removing at least the bulk of the flyslag therefrom, producing a cooled gaseous stream having reduced flyslag content;
- (c) passing cool gas stream having reduced flyslag content from step (b) to a scrubbing zone which includes a loaded scrubbing solution stripping section, and scrubbing said gaseous stream with an effective amount of an aqueous scrubbing solution, and removing HCN, NH.sub.3, and COS and remaining flyslag particles from said gas stream, producing a partially purified gas stream substantially free of flyslag, and an aqueous stream containing flyslag particles from said stripping section, and passing said aqueous stream to a concentrating zone;
- (d) removing from said concentrating zone a concentrated aqueous stream derived from said aqueous stream and having a ratio of flyslag particulate solids to liquid greater than that of the aqueous stream entering said concentrating zone;
- (e) mixing a major portion of said flyslag derived from at least one gasification reactor of step (a) and a minor portion of cementitious material and an effective amount of a composition capable of converting sulfides in said flyslag at least to sulfur, with at least a portion of the concentrated stream from step (d), the concentrated aqueous stream being supplied in a ratio of from about one part to about five parts concentrated aqueous stream per part, by weight, combined total solids of flyslag and cementitious material, and producing a solid flyslag composite having improved disposal properties.
2 more elements
A process for removing flyslag from a synthesis gas stream from which the bulk of the flyslag has already been removed comprising
- (a) passing said gas stream to a scrubbing zone, and scrubbing said gas stream with an effective amount of an aqueous scrubbing liquid, and removing remaining flyslag particles and HCN, NH.sub.3, and COS from said gas stream, producing a partially purified gas stream substantially free of flyslag and a loaded aqueous scrubbing solution;
- (b) stripping the bulk of the HCN, NH.sub.3, and COS from at least a portion of said loaded solution in a stripping zone;
- (c) removing an aqueous stream containing flyslag particles from said stripping zone, and passing said aqueous stream to a concentrating zone;
- (d) removing from said concentrating zone a concentrated aqueous stream derived from said aqueous stream and having a ratio of flyslag particulate solids to liquid greater than that of the aqueous stream entering said concentrating zone;
- (e) mixing a major portion of flyslag having sulfides present therein and a minor portion of cementitious material and an effective amount of a composition capable of converting sulfides in said flyslag at least to sulfur, with at least a portion of the concentrated aqueous stream from step (d), the concentrated aqueous stream being supplied in a ratio of from about one part to about five parts concentrated aqueous stream per part, by weight, combined total solids of flyslag and cementitious material, and producing a solid flyslag composite having improved disposal properties.
2 more elements
A process for the removal of flyslag from a gas stream containing flyslag, the flyslag having sulfides present therein and the gas stream derived from the gasification of coal, comprising
- (a) passing said gas stream containing said flyslag to a solids separation zone, and separating the bulk of the flyslag in said zone, producing solid flyslag and a gas stream having reduced flyslag content;
- (b) passing gas stream having reduced flyslag content from step a) to a scrubbing zone, and scrubbing said gas stream with an effective amount of an aqueous scrubbing liquid, and removing HCN, NH.sub.3, and COS and remaining flyslag particles from said gas stream, producing a partially purified gas stream substantially free of flyslag and a loaded aqueous scrubbing solution;
- (c) stripping the bulk of the HCN, NH.sub.3, and COS from at least a portion of said loaded scrubbing solution in a stripping zone;
- (d) removing an aqueous stream containing flyslag particles from said stripping zone, and passing said aqueous stream to a concentrating zone;
- (e) removing from said concentrating zone a concentrated aqueous stream derived from said aqueous stream and having a ratio of flyslag particulate solids to liquid greater than that of the aqueous stream entering said concentrating zone;
- (f) mixing a major portion of flyslag from step (a), and a minor portion of cementitious material and an effective amount of a composition capable of converting sulfides in said flyslag at least to sulfur, with at least a portion of the concentrated stream from step (e), the concentrated aqueous stream being supplied in a ratio of from about one part to about five parts concentrated aqueous stream per part combined total solids of flyslag and cementitious material, and producing a solid flyslag composite having improved disposal properties.
3 more elements
A process for the gasification of coal comprising
- (a) partially combusting particulate coal in a gasification zone comprising at least one gasification reactor, and producing a hot gaseous stream containing synthesis gas, flyslag having sulfides present therein and minor amounts of HCN, NH.sub.3, and COS;
- (b) cooling said gaseous stream, and removing at least the bulk of the flyslag therefrom, producing a cooled gaseous stream having reduced flyslag content;
- (c) passing cool gas stream having reduced flyslag content from step (b) to a scrubbing zone, and scrubbing said gaseous stream with an effective amount of an aqueous scrubbing liquid, and removing HCN, NH.sub.3 and COS and remaining flyslag particles from said gas stream, producing a partially purified gas stream substantially free of flyslag and a loaded aqueous scrubbing solution;
- (d) stripping the bulk of the HCN, NH.sub.3 and COS from at least a portion of said loaded scrubbing solution in a stripping zone;
- (e) removing an aqueous stream containing flyslag particles from said stripping zone, and passing said aqueous stream to a concentrating zone;
- (f) removing from said concentrating zone a concentrated aqueous stream derived from said aqueous stream and having a ratio of flyslag particulate solids to liquid greater than that of the aqueous stream entering said concentrating zone;
- and
- (g) mixing a major portion of said flyslag derived from at least one gasification reactor of step (a) and a minor portion of cementitious material and an effective amount of a composition capable of converting sulfides in said flyslag at least to sulfur, with at least a portion of the concentrated stream from step (f), the concentrated aqueous stream being supplied in a ratio of from about one part to about five parts concentrated aqueous stream per part, by weight, combined total solids of flyslag and cementitious material, and producing a solid flyslag composite having improved disposal properties.
5 more elements
A process for removing flyslag from a synthesis gas stream from which the bulk of the flyslag has already been removed comprising
- (a) passing said gas stream to a scrubbing zone, and scrubbing said gas stream with an effective amount of an aqueous scrubbing liquid containing ammonium polysulfide, and removing remaining flyslag particles and HCN, NH.sub.3, and COS from said gas stream, producing a partially purified gas stream substantially free of flyslag and a loaded aqueous scrubbing solution containing ammonium thiocyanate;
- (b) hydrolyzing the ammonium thiocyanate in at least a portion of said loaded scrubbing solution, forming a hydrolyzed solution;
- (c) stripping H.sub.2 S, NH.sub.3, and CO.sub.2 from at least a portion of said hydrolyzed solution in a stripping zone;
- (d) removing an aqueous stream of stripped solution containing flyslag particles from said stripping zone, and passing said aqueous stream to a concentrating zone;
- (e) removing from said concentrating zone a concentrated aqueous stream derived from said aqueous stream and having a ratio of flyslag particulate solids to liquid greater than that of the aqueous stream entering said concentrating zone;
- (f) mixing a major portion of flyslag having sulfides present therein, a minor portion of cementitious material and an effective amount of a composition capable of converting sulfides in said flyslag at least to sulfur, with at least a portion of the concentrated aqueous stream from step (e), the concentrated aqueous stream being supplied in a ratio of from about one part to about five parts concentrated aqueous stream per part, by weight, combined total solids of flyslag and cementitious material, and producing a solid flyslag composite having improved disposal properties.
3 more elements
A process for the removal of flyslag from a gas stream containing flyslag, the flyslag having sulfides present therein and the gas stream derived from the gasification of coal, comprising
- (a) passing said gas stream containing said flyslag to a solids separation zone, and separating the bulk of the flyslag in said zone, producing solid flyslag and a gas stream having reduced flyslag content;
- (b) passing gas stream having reduced flyslag content from step (a) to a scrubbing zone, and scrubbing said gas stream with an effective amount of an aqueous scrubbing liquid containing ammonium polysulfide, and removing HCN, NH.sub.3, and COS and remaining flyslag particles from said gas stream, producing a partially purified gas stream substantially free of flyslag and a loaded aqueous scrubbing solution containing ammonium thiocyanate;
- (c) hydrolyzing the ammonium thiocyanate in at least a portion of said loaded scrubbing solution, forming a hydrolyzed solution;
- (d) stripping H.sub.2 S, NH.sub.3, and CO.sub.2 from at least a portion of said hydrolyzed solution in a stripping zone;
- (e) removing an aqueous stream of stripped solution containing flyslag particles from said stripping zone, and passing said aqueous stream to a concentrating zone;
- (f) removing from said concentrating zone a concentrated aqueous stream derived from said aqueous stream and having a ratio of flyslag particulate solids to liquid greater than that of the aqueous stream entering said concentrating zone;
- and
- (g) mixing a major portion of flyslag from step (a), and a minor portion of cementitious material and an effective amount of a composition capable of converting sulfides in said flyslag at least to sulfur, with at least a portion of the concentrated stream from step (f), the concentrated aqueous stream being supplied in a ratio of from about one part to about five parts concentrated aqueous stream per part combined total solids of flyslag and cementitious material, and producing a solid flyslag composite having improved disposal properties.
5 more elements
A process for the gasification of coal comprising
- (a) partially combusting particulate coal in a gasification zone comprising at least one gasification, reactor, and producing a hot gaseous stream containing synthesis gas, flyslag having sulfides present therein and minor amounts of HCN, NH.sub.3, and COS;
- (b) cooling said gaseous stream, and removing at least the bulk of the flyslag therefrom, producing a cooled gaseous stream having reduced flyslag content;
- (c) passing cool gas stream having reduced flyslag content from step (b) to a scrubbing zone, and scrubbing said gaseous stream with an effective amount of an aqueous scrubbing liquid containing ammonium polysulfide, and removing HCN, NH.sub.3 and COS and remaining flyslag particles from said gas stream, producing a partially purified gas stream substantially free of flyslag and a loaded aqueous scrubbing solution containing ammonium thiocyanate;
- (d) hydrolyzing the ammonium thiocyanate in at least a portion of said loaded scrubbing solution, forming a hydrolyzed solution;
- (e) stripping H.sub.2 S, NH.sub.3 and CO.sub.2 from at least a portion of said hydrolyzed solution in a stripping zone;
- (f) removing an aqueous stream of stripped solution containing flyslag particles from said stripping zone, and passing said aqueous stream to a concentrating zone;
- (g) removing from said concentrating zone a concentrated aqueous stream derived from said aqueous stream and having a ratio of flyslag particulate solids to liquid greater than that of the aqueous stream entering said concentrating zone;
- and
- (h) mixing a major portion of flyslag derived from at least one gasification reactor of step (a), a minor portion of cementitious material, and an effective amount of a composition capable of converting sulfides in said flyslag at least to sulfur, with at least a portion of the concentrated stream from step (g), the concentrated aqueous stream being supplied in a ratio of from about one part to about five parts concentrated aqueous stream per part, by weight, combined total solids of flyslag and cementitious material, and producing a solid flyslag composite having improved disposal properties.
6 more elements
Dependencies are inferred from the claim text.