Claims
- 1. In a process for producing sulfur from two hydrogen sulfide containing gas steams, one of said gas streams containing ammonia, wherein said gas streams are subjected to a heat-reaction step followed by a gas-cooling step and at least one catalytic reaction step, the improvement which comprises, a heat reaction which comprises:
- (a) burning the ammonia containing gas stream to form a first combustion mixture in a first heat-reaction chamber, with air introduced into the first heat-reaction chamber wherein the quantity of air is such that the ratio .rho., of the quantity of air injected into the first heat-reaction chamber to the quantity of air theoretically required for the total combustion of the hydrogen sulfide and ammonia to sulfur dioxide and nitrogen, respectively, in said first heat-reaction chamber is between 0.4 and 1 and the temperature of the gases in said first heat-reaction chamber is maintained from 1350.degree. to 1550.degree. C.,
- (b) passing said first combustion mixture to a second heat-reaction chamber;
- (c) burning the gas stream free of ammonia in said second heat-reaction chamber with a quantity of air sufficient to provide a molar ratio of H.sub.2 S/SO.sub.2 in the gas mixture leaving said second heat-reaction chamber of about 2/1 and maintaining the temperature of the gases in the second heat-reaction chamber at from 1000.degree. to 1500.degree. C.
- 2. In a process for producing sulfur from two hydrogen sulfide containing gas streams, one of said gas streams containing ammonia, wherein said gas streams are subjected to a heat-reaction step followed by an indirect gas-cooling step and at least one catalytic reaction step, the improvement which comprises a heat reaction which comprises:
- (a) burning the ammonia containing gas stream to form a first combustion mixture in a first heat-reaction chamber with air introduced into the first heat-reaction chamber, wherein the quantity of air is such that the ratio .rho., of the quantity of air injected into the first heat-reaction chamber to the quantity of air theoretically required for the total combustion of the hydrogen sulfide and ammonia to sulfur dioxide and nitrogen respectively, in said first heat-reaction chamber is between 0.7 and 1 and the temperature of the gases in said first heat-reaction chamber is maintained between 1350.degree. and 1550.degree. C.;
- (b) passing said first combustion mixture to a second heat-reaction chamber;
- (c) burning the gas stream free of ammonia in said second heat-reaction chamber in an amount in which the molar flow-rate of hydrogen sulfide in said second gas stream entering the second heat-reaction chamber is at least twice the molar flow-rate of hydrogen sulfide in the ammonia containing gas stream entering the first heat-reaction chamber, with a quantity of air sufficient to provide a molar ratio of H.sub.2 S/SO.sub.2 in the gas mixture leaving said heat-reaction chamber of about 2/1 and maintaining the temperature of the gases in the second heat-reaction chamber between 1000.degree. and 1500.degree. C.
- 3. In a process for producing sulfur from two hydrogen sulfide containing gas streams, one of said gas streams containing ammonia, wherein said gas streams are subjected to a heat-reaction step, by combustion with air, followed by an indirect gas-cooling step and at least one catalytic reaction step, the improvement which comprises, a heat reaction which comprises:
- (a) preheating the ammonia containing gas stream and air to a temperature of 150.degree. to 250.degree. C.;
- (b) burning the preheated ammonia containing gas stream to form a first combustion mixture, in a first heat-reaction chamber, with a quantity of said preheated air introduced into the first heat-reaction chamber such that the ratio .rho., of the quantity of air injected into the first heat-reaction chamber to the quantity of air theoretically required for the total combustion of the hydrogen sulfide and ammonia to sulfur dioxide and nitrogen respectively, in said first heat-reaction chamber is between 0.4 and 0.7 and maintaining the temperature of the gases in said first heat-reaction chamber between 1350.degree. and 1550.degree. C.;
- (c) passing said first combustion mixture to a second heat-reaction chamber;
- (d) burning the gas stream free of ammonia in said second heat-reaction chamber in an amount in which the molar flow-rate of hydrogen sulfide in said second gas stream entering the second heat-reaction chamber, is less than twice the molar flow-rate of hydrogen sulfide in the ammonia containing gas stream entering the first heat-reaction chamber, with a quantity of air sufficient to provide a molar ratio of H.sub.2 S/SO.sub.2 in the gas mixture leaving said heat reaction chamber of about 2/1 and maintaining the temperature of the gases in the second heat reaction chamber between 1000.degree. and 1500.degree. C.
- 4. A process according to claim 3 wherein the gases from the heat reaction step are indirectly cooled in a steam generating zone and the ammonia containing gas and the air entering said first reaction chamber are preheated by indirect heat exchange with steam produced in said steam generating zone.
- 5. A process as define in any of claims 1, 2, 3 or 4 in which effluent gases from the second heat-reaction chamber pass through a gas-residence chamber, at a temperature of 1,000.degree. to 1,500.degree. C., before being conveyed to the cooling stage preceding the catalytic reaction stage.
- 6. A process as defined in claim 5, in which the gases remain for periods of 0.2 to 1.2 second in each heat-reaction chamber and in the high-temperature residence chamber, the periods of time being approximately the same in all chambers.
- 7. A process as defined in claims 1, 2, 3 or 4, in which the ammonia free gas stream entering the second heat-reaction chamber contains a total concentration of between 0.4 and 15% by volume of hydrocarbons.
- 8. A process according to claim 7 wherein the ammonia-free gas stream entering the second heat-reaction chamber contains a total concentration of between 1 and 5%, by volume, of hydrocarbons.
Priority Claims (1)
Number |
Date |
Country |
Kind |
78 12899 |
May 1978 |
FRX |
|
Parent Case Info
This is a continuation of application Ser. No. 33,169, filed Apr. 25, 1979.
US Referenced Citations (4)
Continuations (1)
|
Number |
Date |
Country |
Parent |
33169 |
Apr 1979 |
|