Claims
- 1. An improved process for disposing of an industrial waste stream containing chemically bound nitrogen compounds comprising:
- burning the industrial waste stream containing chemically bound nitrogen compounds at a temperature greater than about 2000.degree. F. in the presence of a stoichiometric excess of an amount of a reducing agent required for stoichiometric reduction of available oxygen to provide a combustion effluent substantially free of oxides of nitrogen; and
- reacting the combustion effluent with an effective amount of a dilute oxygen containing gaseous stream to achieve oxidation of the combustibles present in the combustion effluent at a temperature of about 1600.degree. F. to about 1800.degree. F. and without effecting flame propagation within the dilute oxygen containing gaseous stream to produce an oxidation effluent substantially free of oxides of nitrogen.
- 2. The process of claim 1 wherein the dilute oxygen containing stream contains less than about 21 volume percent oxygen.
- 3. The process of claim 2 wherein the effective amount of the oxygen in the gaseous stream is a stoichiometric excess, based on the amount of the combustibles present in the combustion effluent.
- 4. The process of claim 3 wherein the chemically bound nitrogen compounds are selected from the group consisting of oxides of nitrogen ammonia and compounds in which a nitrogen atom is chemically bonded to a carbon atom.
- 5. The process of claim 1 or 3 which further comprises cooling the oxidation effluent in a heat exchanger to recover heat energy.
- 6. The process of claim 5 which further comprises recycling a portion of the cooled oxidation effluent as an inert carrier gas for the dilution of the oxygen containing flameless stream employed to achieve flameless oxidation of the combustibles present in the combustion effluent and prevent flame propagation.
- 7. The process of claim 5 which further comprises recycling a portion of the cooled oxidation effluent as a cooling gas for maintaining the temperature of the waste stream at a temperature greater than about 2000.degree. F. and less than about 3000.degree. F. during the burning of the waste stream.
- 8. The process of claim 5 which further comprises recycling a portion of the cooled oxidation effluent as a coolant gas to the oxidation zone to maintain the temperature of the combustion effluent at the temperature of from about 1600.degree. F. to about 1800.degree. F. during oxidation of the combustion effluent.
- 9. The process of claim 1 wherein the burning of the waste stream is carried out at a temperature greater than 2000.degree. F. and less than 3000.degree. F.
- 10. The process of claim 9 which further comprises venting at least a portion of the oxidation effluent to the atmosphere.
- 11. The process of claim 1 wherein the reducing agent is a hydrocarbon, the amount of the hydrocarbon added during the burning of the waste stream being less than about 200 percent of the stoichiometric amount required for the stoichiometric reduction of available oxygen present during the burning of the waste stream.
- 12. The process of claim 11 wherein the hydrocarbon is a low molecular weight hydrocarbon.
- 13. The process of claim 12 wherein the low molecular weight hydrocarbon is selected from the group consisting of methane, ethane, and natural gas.
- 14. A process for reducing the concentration of oxides of nitrogen in an effluent stream so that the effluent stream can be vented into the atmosphere comprising:
- burning a waste stream containing chemically bound nitrogen compounds with effective amounts of air and a reducing agent at a temperature in the range of greater than about 2000.degree. F. and less than about 3000.degree. F. to provide a combustion effluent, the reducing agent being present in an amount to provide a stoichiometric excess, based on the amount of available oxygen, but less than 200 percent of such stoichiometric amount; and
- contacting the combustion effluent with an effective amount of an oxygen containing gaseous stream to achieve oxidation of combustibles present in the combustion effluent without effecting flame propagation at a temperature in the range of from about 1600.degree. F. to about 1800.degree. F. so as to minimize formation of oxides of nitrogen and produce an oxidation effluent, the oxygen containing gaseous streeam having a stoichiometric excess of oxygen based on the amount of combustibles present in the effluent and less than 21 volume percent oxygen.
- 15. The process of claim 14 wherein the chemically bound nitrogen compounds are selected from the group consisting of oxides of nitrogen, ammonia, and compounds in which a nitrogen atom is chemically bonded to a carbon atom.
- 16. The process of claim 15 which further comprises cooling the oxidation effluent in a heat exchanger to recover heat energy.
- 17. The process of claim 15 which further comprises recycling a portion of the cooled oxidation effluent as an inert carrier gas for dilution of the oxygen containing gaseous stream.
- 18. The process of claim 15 or 17 which further comprises recycling a portion of the cooled oxidation effluent as a coolant gas for maintaining the burning temperature of the waste stream at a temperature greater than about 2000.degree. F. and less than about 3000.degree. F.
- 19. The process of claim 15 which further comprises recycling a portion of the cooled oxidation effluent as coolant gas to maintain the temperature of the combustion effluent stream at the temperature of from about 1600.degree. F. to about 1800.degree. F. during oxidation of the combustion effluent.
- 20. The process of claim 14 which further comprises venting the oxidation effluent to the atmosphere.
- 21. The process of claim 14 wherein the reducing agent is a low molecular weight hydrocarbon.
- 22. The proces of claim 21 wherein the low molecular weight hydrocarbon is selected from the group consisting of methane, ethane, and natural gas.
CROSS REFERENCE TO RELATED APPLICATION
This is a continuation-in-part application of a U.S. patent application entitled "Process for Reduction of Oxides of Nitrogen", application Ser. No. 348,840, filed Feb. 16, 1982, and now U.S. Pat. No. 4,405,587.
US Referenced Citations (8)
Foreign Referenced Citations (3)
Number |
Date |
Country |
54-50470 |
Apr 1979 |
JPX |
54-38431 |
Nov 1979 |
JPX |
667342 |
Feb 1952 |
GBX |
Continuation in Parts (1)
|
Number |
Date |
Country |
Parent |
348840 |
Feb 1982 |
|