Use of coal feedstock to a coal gasification plant for removing sulfur from a gaseous stream

Abstract

A process of utilizing a portion of a coal feedstock to a coal gasification plant for the removal of sulfur compounds from a gaseous stream comprising sulfur dioxide and hydrogen sulfide, particularly a tail gas stream from a sulfur recovery plant, by contacting the gaseous stream with the coal feedstock. The laden coal is subsequently fed to a coal gasification plant and gasified to make synthesis gas.

I claim: 
     
       1. A process for the desulfurization of a sulfur compound-containing gaseous stream, which process comprises the steps of: (a) introducing said sulfur compound-containing gaseous stream into a contact zone comprising solid particles of coal, and   (b) contacting the sulfur compound-containing gaseous stream in said contact zone with said coal causing the removal of said sulfur compounds from said sulfur compound-containing gaseous stream in the presence of said coal and thereby producing a laden coal and a contact zone effluent stream lean in sulfur compounds;   wherein said sulfur compound-containing gaseous stream introduced to the contact zone in (a) comprises more than 0.05% by volume of sulfur dioxide;   wherein in step (b), the contact zone is maintained at a temperature at which no substantial amount of coal within said contact zone is oxidized.   wherein the laden coal from step (b) is passed to a coal gasifier and is gasified to produce synthesis gas.   
     
     
       2. A process as described in claim 1, wherein said sulfur compound-containing stream in step (a) further comprises hydrogen sulfide. 
     
     
       3. The process as described in claim 1, wherein in step (b), the oxygen concentration within the contact zone is about 0-8% by volume. 
     
     
       4. The process as described in claim 3, wherein in step (b), the temperature within the contact zone is maintained at from about 25° C. to about 600° C. 
     
     
       5. The process as described in claim 1, wherein in step (b), the oxygen concentration in the contact zone is from about 0% to about 1% by volume. 
     
     
       6. The process as described in claim 5, wherein in step (b), the temperature in the contact zone is maintained at from about 25° C. to about 1000° C. 
     
     
       7. The process as described in claim 1, wherein the coal used in step (b) has a mean pore radius of more than 20 angstroms, and a surface area of less than 1000 square meters per gram. 
     
     
       8. The process as described in claim 1, wherein the coal utilized for the desulfurization process is a mixture which comprises a coal and at least one ingredient selected from the 
     
     
       9. A process for the removal of sulfur-containing compounds from a Claus or SUPERCLAUS sulfur recovery plant effluent stream, which process comprises the steps of: (a) introducing said Claus or SUPERCLAUSE sulfur recovery plant effluent stream into a contact zone comprising solid particles of coal;   (b) contact the Clause or SUPERCLAUSE sulfur recovery plant effluent stream in said contact zone with said coal causing the removal of said sulfur compounds from said Claus or SUPERCLAUSE sulfur recovery plant effluent stream in the presence of said coal and thereby producing a laden coal and a contact zone effluence stream lean in sulfur compounds,   wherein said Clause or SUPERCLAUSE sulfur recovery plant effluent stream introduced to the contact zone in (a) comprises sulfur dioxide and hydrogen sulfide;   wherein in step (b), the contact zone is maintained at a temperature at which no substantial amount of coal within said contact zone is oxidized; wherein the laden coal from step (b) is passed to a coal gasifier and is gasified to produce synthesis gas.   
     
     
       10. The process as described in claim 9, wherein the oxygen concentration in the contact zone is from about 0% to 1% by volume. 
     
     
       11. The process as described in claim 9, wherein the coal used in step (b) is a fine powder of less than 500 microns and the coal used in step (b) has a mean pore radius of more than 100 angstroms and a surface area of less than 150 square meters per gram. 
     
     
       12. A process for utilizing a portion of a coal feedstock to a coal gasification plant for the removal of sulfur compounds from a sulfur compound-containing gaseous stream, which process comprises the steps of: (a) introducing the sulfur compound-containing gaseous stream into a contact zone comprising said portion of coal feedstock,   (b) contacting the sulfur compound-containing gaseous stream in said contact zone with said coal causing the removal of said sulfur compounds from said sulfur compound-containing gaseous stream in the presence of said coal and thereby producing a laden coal and a contact zone effluent stream lean in sulfur compounds,   (c) passing said laden coal from (b) to a coal gasifier, and   (d) gasifying said laden coal at gasifying conditions; wherein said sulfur compound-containing gaseous stream in step (a) comprises more than 0.05% by volume of sulfur dioxide;   wherein step (b), the contact zone is maintained at a temperature at which no substantial amount of coal within said contact zone is oxidized.   
     
     
       13. The process as described in claim 12, wherein in step (b), the oxygen concentration within the contact zone is about 0-8% by volume. 
     
     
       14. The process as described in claim 13, wherein in step (b), the temperature within the contact zone is maintained at from about 25° C. to about 600° C. 
     
     
       15. The process as described in claim 12, wherein in step (b), the oxygen concentration in the contact zone is from about 0% to about 1% by volume. 
     
     
       16. The process as described in claim 15, wherein in step (b), the temperature in the contact zone is maintained at from about 60° C. to about 1000° C. 
     
     
       17. The process as described in claim 12, wherein said sulfur compound-containing stream in step (a) further comprises hydrogen sulfide. 
     
     
       18. A process for the utilization of a portion of a feedstock coal to a coal gasification plant for the removal of sulfur-containing compounds from a Claus sulfur recovery plant effluent stream, which process comprises the steps of: introducing said Claus sulfur recovery plant effluent stream into a contact zone comprising solid particles of coal;   (b) contacting the Claus sulfur recovery plant effluent stream in said contact zone with said coal causing the removal of said sulfur compounds from said Clause sulfur recovery plant effluent stream in the presence of said coal at a temperature from about 25° C. to about 500° C. and thereby producing a laden coal and a contact zone effluent stream lean in sulfur compounds,   (c) passing said laden coal from (b) to a coal gasifier, and   (d) gasifying said laden coal at gasifying conditions;   wherein said Claus sulfur recovery plant effluent stream introduced to the contact zone in (a) comprises sulfur dioxide and hydrogen sulfide; wherein in step (b), the contact zone is maintained at a temperature at which no substantial amount of coal within said contact zone is oxidized; wherein the oxygen concentration in the contact zone is from about 0% to about 0.1% by volume; wherein the coal used in step (b) is a fine powder of less than 500 microns and the coal used in step (b) has a means pore radius of more than 100 angstroms and a surface area of less than of about 100 square meters per gram.   
     
     
       19. The process as described in claim 5, wherein said Claus sulfur recovery plant and the coal gasifier in (c) are located in the same coal gasification plant. 
     
     
       20. The process as described in claim 19, wherein said Claus sulfur recovery plant is not located in the coal gasification plant where the coal gasifier in (c) is located.