Method for recovery of elemental sulfur from low hydrogen sulfide sulfur plant feed gas

Claim 2

MIXING SAID FEED STREAM WITH AIR,

Claim 3

mixing said feed stream with air,

Claim 4

mixing said feed stream with air,

Claim 5

In a process for the recovery of free sulfur from a feed stream containing less than 45 mol % H2S and contaminated with hydrocarbons, the improvement comprising mixing a portion of said stream with a hydrocarbon gas and air and burning the resulting mixture in the forward portion of a combustion zone, said air being present in an amount sufficient to convert the hydrocarbon gas to CO2 and H2O and to provide an H2S/SO2 molar ratio not greater than about 0.2 whereby the presence of SO3 is suppressed, discharging the hot combustion products thus formed into the rearward portion of said combustion zone where they are mixed with the remainder of said feed stream at a temperature ranging from about 2,000*F to about 2,800*F, withdrawing an effluent from said rearward portion containing H2S and SO2 in an approximate molar ratio of 2:1 and substantially free from hydrocarbons, removing elemental sulfur from said effluent, and thereafter reacting the H2S and SO2 in the resulting sulfuR denuded effluent in contact with a catalyst for the reaction to produce sulfur in a known manner.

Claim 6

In a process for the recovery of free sulfur from a feed stream containing less than 45 mol % H2S and contaminated with hydrocarbons, the improvement comprising mixing a portion of said stream with a hydrocarbon gas and air and burning the resulting mixture in the forward portion of a combustion zone, said air being present in an amount sufficient to convert the hydrocarbon gas to CO2 and H2O and to provide an H2S/SO2 molar ratio not greater than about 0.2 whereby the presence of SO3 is suppressed, discharging the hot combustion products thus formed into the rearward portion of said combustion zone where they are mixed with the remainder of said feed stream at a temperature ranging from about 2,000*F to about 2,800*F, withdrawing an effluent from said rearward portion containing H2S and SO2 in an approximate molar ratio of 2:1 and substantially free from hydrocarbons, removing elemental sulfur from said effluent, and thereafter reacting the H2S and SO2 in the resulting sulfuR denuded effluent in contact with a catalyst for the reaction to produce sulfur in a known manner.

Claim 7

simultaneously and separately burning a gaseous hydrocarbon with air in an amount in excess of that necessary to convert said gaseous hydrocarbon into CO2 and water, discharging the products from steps 1 and 2 into a noncatalytic reaction zone where free sulfur is formed at a temperature ranging from about 2,000* to about 2,800*F, withdrawing an effluent from said reaction zone containing H2S and SO2 in a molar ratio of about 2:1, removing the sulfur therefrom, and thereafter reacting the H2S and SO2 in the resulting sulfur-denuded effluent in contact with a catalyst for the reaction to produce sulfur in a known manner.

Claim 8

simultaneously and separately burning a gaseous hydrocarbon with air in an amount in excess of that necessary to convert said gaseous hydrocarbon into CO2 and water, discharging the products from steps 1 and 2 into a noncatalytic reaction zone where free sulfur is formed at a temperature ranging from about 2,000* to about 2,800*F, withdrawing an effluent from said reaction zone containing H2S and SO2 in a molar ratio of about 2:1, removing the sulfur therefrom, and thereafter reacting the H2S and SO2 in the resulting sulfur-denuded effluent in contact with a catalyst for the reaction to produce sulfur in a known manner.

Claim 9

The process of claim 1 wherein said air and said portion of said feed stream are preheated to from about 300* to about 600*F prior to introduction thereof into said combustion zone.

Claim 10

SIMULTANEOUSLY AND SEPARATELY BURNING A GASEOUS HYDROCARBON WITH AIR IN AN AMOUNT IN EXCESS OF THAT NECESSARY TO CONVERT SAID GASEOUS HYDROCARBON INTO CO2 AND WATER, DISCHARGING THE PRODUCTS FROM STEPS 1 AND 2 INTO NONCATALYTIC REACTION ZONE WHERE FREE SULFUR IS FORMED AT A TEMPERATURE RANGING FROM ABOUT 2,000* TO ABOUT 2,800*F, WITHDRAWING AN EFFLUENT FROM SAID REACTION ZONE CONTAINING H2S AND SO2 IN A MOLAR RATIO OF ABOUT 2:1, REMOVING THE SULFUR THEREFROM, AND THEREAFTER REACTING THE H2S AND SO2 IN THE RESULTING SULFUR-DENUDED EFFLUENT IN CONTACT WITH A CATALYST FOR THE REACTION TO PRODUCE SULFUR IN A KNOWN MANNER.

Claim 11

SIMULTANEOUSLY AND SEPARATELY BURNING A GASEOUS HYDROCARBON WITH AIR IN AN AMOUNT IN EXCESS OF THAT NECESSARY TO CONVERT SAID GASEOUS HYDROCARBON INTO CO2 AND WATER, DISCHARGING THE PRODUCTS FROM STEPS 1 AND 2 INTO NONCATALYTIC REACTION ZONE WHERE FREE SULFUR IS FORMED AT A TEMPERATURE RANGING FROM ABOUT 2,000* TO ABOUT 2,800*F, WITHDRAWING AN EFFLUENT FROM SAID REACTION ZONE CONTAINING H2S AND SO2 IN A MOLAR RATIO OF ABOUT 2:1, REMOVING THE SULFUR THEREFROM, AND THEREAFTER REACTING THE H2S AND SO2 IN THE RESULTING SULFUR-DENUDED EFFLUENT IN CONTACT WITH A CATALYST FOR THE REACTION TO PRODUCE SULFUR IN A KNOWN MANNER.

Claim 12

The process of claim 3 wherein the air and said stream are preheated to from about 300 to about 600*F prior to step 1.