Coal combustion process
AssigneeExxon Research & Engineering Co.
InventorsRichard K. Lyon, Howard Freund
Life of this patent
Estimating the term…
Abstract
Disclosed is a process for combusting coal wherein the emission of SO.sub.x or the emission of SO.sub.x and NO.sub.x are minimized. The process comprises (a) providing a coal containing at least twice as much organic calcium than sulfur; (b) burning the coal at a temperature greater than about 1200.degree. C. under reducing conditions; (c) separating the solid effluents from the gaseous effluents; and (d) burning the gaseous effluents at a temperature from about 1000.degree. C. to 1500.degree. C. under oxidizing conditions.
Claims6
A coal combustion process wherein the emission of SO.sub.x is minimized which process comprises:
- (a) providing a coal containing an organic calcium to sulfur ratio of at least 2 to 1 for coal containing less than 1 wt.% sulfur and at least 1 to 1 for coal containing greater than 1 wt.% sulfur;
- (b) burning the coal at temperatures greater than about 1200.degree. C. in a first combustion zone in the presence of an oxidizing agent but under reducing conditions such that the equivalence ratio of coal to oxidizing agent is at least 1.5;
- (c) separating the resulting solid effluent from the gaseous effluent from the first combustion zone;
- and
- (d) burning the gaseous effluent at a temperature from about 1000.degree. C. to about 1500.degree. C. in a second combustion zone under oxidizing conditions.
A coal combustion process wherein the emission of SO.sub.x and NO.sub.x is minimized which process comprises:
- (a) providing a coal containing an organic calcium to sulfur ratio of at least 2 to 1 for coal containing less than 1 wt.% sulfur and at least 1 to 1 for coal containing greater than 1 wt.% sulfur;
- (b) burning the coal at temperatures greater than about 1400.degree. C. in a first combustion zone in the presence of an oxidizing agent but under reducing conditions such that the equivalence ratio of coal to oxidizing agent is at least 1.5;
- (c) separating the resulting solid effluent from the gaseous effluent resulting from the first combustion zone;
- and
- (d) burning the gaseous effluent at a temperature from about 1000.degree. C. to about 1500.degree. C. in a second combustion zone under oxidizing conditions.
Dependencies are inferred from the claim text.