Process for the conversion of hydrogen sulfide in gas streams of low hydrogen sulfide concentration to sulfur

Claim 2

A PROCESS FOR THE PRODUCTION OF SULFUR FROM ACID GAS STREAMS OF LOW HYDROGEN SULFIDE CONCENTRATION AND WHICH CONTAIN CARBONACEOUS IMPURITIES WHICH COMPRISES; A. INDIRECTLY HEATING THE ACID GAS STREAM OF LOW HYDROGEN SULFIDE CONCENTRATION TO A TEMPERATURE OF FROM ABOUT 400*F TO ABOUT 650*F TO PREVENT CONVERSION OF THE CARBONACEOUS IMPURITIES TO PREVENT THE FORMATION OF TARRY MATERIALS FROM THE CARBONACEOUS IMPURITIES; B. GENERATING A SULFUR DIOXIDE GAS STREAM BY THE COMBUSTION OF SULFUR CONTAINING CARBONACEOUS IMPURITIES IN THE PRESENCE OF AN OXYGEN CONTAINING GAS IN A HIGH TEMPERATURE FLAME ZONE, THE AMOUNT OF OXYGEN FED TO SAID FLAME ZONE BEING SUFFICIENT TO GENERATE SULFUR DIOXIDE IN AN AMOUNT EQUAL TO ABOUT 50% OF THE HYDROGEN SULFIDE CONTAINED IN THE ACID GAS STREAM OF LOW HYDROGEN SULFIDE CONCENTRATION AND THE AMOUNT OF SULFUR FED TO SAID FLAME ZONE BEING AT LEAST ABOUT 25% GREATER THAN THE AMOUNT REQUIRED FOR CONVERSION TO SULFUR DIOXIDE TO PREVENT THE FORMATION OF SULFUR TRIOXIDE AND CONVERT CONTAINED CARBONACEOUS IMPURITIES TO GASEOUS CARBON-SULFUR COMPOUNDS; C. COOLING THE SULFUR DIOXIDE GAS STREAM TO A TEMPERATURE OF FROM ABOUT 270*F TO ABOUT 750*F TO CONDENSE EXCESS SULFUR FREE OF CARBONACEOUS IMPURITIES FROM THE SULFUR DIOXIDE GAS STREAM; D. COMBINING THE HEATED ACID GAS STREAM OF LOW HYDROGEN SULFIDE CONCENTRATION WITH THE COLLED SULFUR DIOXIDE GAS STREAM AND CATALYTICALLY CONVERTING THE COMBINED HYDROGEN SULFIDE AND SULFUR DIOXIDE TO ELEMENTAL SULFUR WITHOUT CONVERTING THE CARBONACEOUS IMPURITIES TO TARRY MATERIALS; E. CONDENSING THE FORMED ELEMENTAL SULFUR WITH ENTRAINED CARBONACEOUS IMPURITIES FROM THE GAS STREAM AND RECYCLING A PORTION OF THE FORMED ELEMENTAL SULFUR CONTAINING THE CARBONACEOUS IMPURITIES TO SAID FLAME ZONE.

Claim 3

A process as claimed in claim 1 in which the flame zone is maintained at a temperature above about 2,000*F.

Claim 4

A process as claimed in claim 1 in which the flame zone is maintained at a temperature from about 2,100*F to about 2, 800*F.

Claim 5

A process as claimed in claim 1 in which the acid gas stream is heated to a temperature from about 430*F to about 500*F.

Claim 6

A process as claimed in claim 3 in which the acid gas stream is heated to a temperature from about 430*F to about 500*F.

Claim 7

A process for the production of sulfur from acid gas streams of low hydrogen sulfide concentration and which contains carbonaceous impurities which comprises: a. indirectly heating acid gas stream of low hydrogen sulfide concentration to a temperature of from about 400*F to about 650*F to prevent the conversion of carbonaceous impurities to tarry materials; b. generating a sulfur dioxide gas stream by the combustion of sulfur containing carbonaceous impurities in the presence of an oxygen containing gas in a high temperature flame zone, the amount of oxygen fed to said flame zone being sufficient to generate sulfur dioxide in an amount equal to about 50% of hydrogen sulfide contained in the acid gas stream of low hydrogen sulfide concentration and the amount of sulfur fed to said flame zone being at least about 25 percent greater than the amount required for conversion to sulfur dioxide to prevent the formation of sulfur trioxide and to convert the contained carbonaceous impurities to carbon sulfur compounds; c. cooling the sulfur dioxide gas stream to a temperature of from about 270*F to about 750*F to condense excess sulfur from the sulfur dioxide gas stream and passing the condensed excess sulfur to a first liquid sulfur collection zone; d. combining the heated acid gas stream of low hydrogen sulfide concentration with the cooled sulfur dioxide gas stream and catalytically converting the combined hydrogen sulfide and sulfur dioxide to elemental sulfur; e. condensing the formed elemental sulfur with entrained carbonaceous impurities from the gas stream leaving a residual gas stream; f. collecting the formed elemental sulfur as liquid sulfur containing the carbonaceous impurities in a second liquid sulfur collection zone; g. recycling liquid sulfur containing the carbonaceous impurities from said second liquid sulfur collection zone to said flame zone in an amount sufficient to meet the sulfur requirements of said flame zone.

Claim 8

A process for the production of sulfur from acid gas streams of low hydrogen sulfide concentration and which contains carbonaceous impurities which comprises: a. indirectly heating acid gas stream of low hydrogen sulfide concentration to a temperature of from about 400*F to about 650*F to prevent the conversion of carbonaceous impurities to tarry materials; b. generating a sulfur dioxide gas stream by the combustion of sulfur containing carbonaceous impurities in the presence of an oxygen containing gas in a high temperature flame zone, the amount of oxygen fed to said flame zone being sufficient to generate sulfur dioxide in an amount equal to about 50% of hydrogen sulfide contained in the acid gas stream of low hydrogen sulfide concentration and the amount of sulfur fed to said flame zone being at least about 25 percent greater than the amount required for conversion to sulfur dioxide to prevent the formation of sulfur trioxide and to convert the contained carbonaceous impurities to carbon sulfur compounds; c. cooling the sulfur dioxide gas stream to a temperature of from about 270*F to about 750*F to condense excess sulfur from the sulfur dioxide gas stream and passing the condensed excess sulfur to a first liquid sulfur collection zone; d. combining the heated acid gas stream of low hydrogen sulfide concentration with the cooled sulfur dioxide gas stream and catalytically converting the combined hydrogen sulfide and sulfur dioxide to elemental sulfur; e. condensing the formed elemental sulfur with entrained carbonaceous impurities from the gas stream leaving a residual gas stream; f. collecting the formed elemental sulfur as liquid sulfur containing the carbonaceous impurities in a second liquid sulfur collection zone; g. recycling liquid sulfur containing the carbonaceous impurities from said second liquid sulfur collection zone to said flame zone in an amount sufficient to meet the sulfur requirements of said flame zone.

Claim 9

A process as claimed in claim 6 in which the residual gas stream is passed to at least one additional catalytic sulfur conversion stage and the sulfur formed is condensed and collected in said first liquid sulfur collection zone.

Claim 10

A process as claimed in claim 6 in which the flame zone is maintained at a temperature above about 2,000*F.

Claim 11

A process as claimed in claim 7 in which the flame zone is maintained at a temperature above about 2,000*F.

Claim 12

A process as claimed in claim 6 in which the flame zone is maintained at a temperature from about 2,100*F to about 2,800*F.

Claim 13

A process as claimed in claim 7 in which the flame zone is maintained at a temperature from about 2,100*F to about 2,800*F.

Claim 14

A process as claimed in claim 6 in which the acid gas stream is heated to a temperature from about 430*F to about 500*F.

Claim 15

A process as claimed in claim 7 in which the acid gas stream is heated to a temperature from about 430*F to about 500*F.