US4624840A — Non-catalytic method for reducing the concentrati…

Claim 1

Independent Claim 298 words

A process for reducing NO concentration of a combustion effluent containing NO and at least 0.1 volume percent oxygen when at least a portion of the combustion effluent is at a temperature within the range of about 1300° K. to about 1600° K. which process comprises injecting ammonia into the combustion effluent, in a cooling zone wherein the combustion effluent is cooling at a rate of at least about 250° K. per second wherein the amount of ammonia and the point of injection are determined by the solution of a set of simultaneous equations derived from the kinetic model: ______________________________________ Rate constant K = AT.sup.n exp (-E/(1.98)T) REACTION A n E ______________________________________ NH.sub.3 +O=NH.sub.2 +H.sub.2 .246E+14 0.0 17071. NH.sub.3 +O=NH.sub.2 +OH .150E+13 0.0 6040. NH.sub.3 +OH=NH.sub.2 +H.sub.2 O .326E+13 0.0 2120. HNO+M=NO+H+M .186E+17 0.0 48680. HNO+OH=NO+H.sub.2 O .360E+14 0.0 0. NH.sub.2 +HNO=NH.sub.3 +NO .175E+15 0.0 1000. NH.sub.2 +NO=NNH+OH .610E+20 -2.46 1866. NH.sub.2 +O.sub.2 =HNO+OH .510E+14 0.0 30000. NNH+NH.sub.2 =N.sub.2 +NH.sub.3 .100E+14 0.0 0. NH.sub.2 +O=NH+OH .170E+14 0.0 1000. NH.sub.2 +OH=NH+H.sub.2 O .549E+11 0.68 1290. NH.sub.2 +H=NH+H.sub.2 .500E+12 0.5 2000. NH+O.sub.2 =NHO+O .300E+14 0.0 3400. H.sub.2 +OH=H.sub.2 O+H .220E+14 0.0 5150. H+O.sub.2 =OH+O .220E+15 0.0 16800. O+ H.sub.2 =OH+H .180E+11 1.0 8900. H+HO.sub.2 =OH+OH .250E+15 0.0 1900. O+HO.sub.2 =O.sub.2 +OH .480E+15 0.0 1000. OH+HO.sub.2 =H.sub.2 O+O.sub.2 .500E+14 0.0 1000. OH+OH=O+H.sub.2 O .630E+13 0.0 1090. HO.sub.2 +NO=NO.sub.2 +OH .343E+13 0.0 -260. H+NO.sub.2 =NO+OH .350E+15 0.0 1500. O+NO.sub.2 =NO+O.sub.2 .100E+14 0.0 600. H+O.sub.2 +M=HO.sub.2 +M .150E+16 0.0 -995. H.sub.2 O/21** NNH+M=N.sub.2 +H+M .200E+15 0.0 30000. NO.sub.2 +M=NO+O+M .110E+17 0.0 66000. NH.sub.3 +M=NH.sub.2 +H+M .480E+17 0.0 93929. O+O+M=O.sub.2 +M .138E+19 -1.0 340. NH.sub.2 +NO=N.sub.2 +H.sub.2 O .910E+20 -2.46 1866. NNH+OH=N.sub.2 +H.sub.2 O .300E+14 0.0 0. NNH+NO=N.sub.2 +HNO .906E+12 0.0 0. ______________________________________ **i.e. A=21 × .15E+16 for H.sub.2 O as "third body" .

Claim 2

Dependent Claim 298 words

A process for reducing NO concentration of a combustion effluent containing NO and at least 0.1 volume percent oxygen when at least a portion of the combustion effluent is at a temperature within the range of about 1300° K. to about 1600° K. which process comprises injecting ammonia into the combustion effluent, in a cooling zone wherein the combustion effluent is cooling at a rate of at least about 250° K. per second wherein the amount of ammonia and the point of injection are determined by the solution of a set of simultaneous equations derived from the kinetic model: ______________________________________ Rate constant K = AT.sup.n exp (-E/(1.98)T) REACTION A n E ______________________________________ NH.sub.3 +O=NH.sub.2 +H.sub.2 .246E+14 0.0 17071. NH.sub.3 +O=NH.sub.2 +OH .150E+13 0.0 6040. NH.sub.3 +OH=NH.sub.2 +H.sub.2 O .326E+13 0.0 2120. HNO+M=NO+H+M .186E+17 0.0 48680. HNO+OH=NO+H.sub.2 O .360E+14 0.0 0. NH.sub.2 +HNO=NH.sub.3 +NO .175E+15 0.0 1000. NH.sub.2 +NO=NNH+OH .610E+20 -2.46 1866. NH.sub.2 +O.sub.2 =HNO+OH .510E+14 0.0 30000. NNH+NH.sub.2 =N.sub.2 +NH.sub.3 .100E+14 0.0 0. NH.sub.2 +O=NH+OH .170E+14 0.0 1000. NH.sub.2 +OH=NH+H.sub.2 O .549E+11 0.68 1290. NH.sub.2 +H=NH+H.sub.2 .500E+12 0.5 2000. NH+O.sub.2 =NHO+O .300E+14 0.0 3400. H.sub.2 +OH=H.sub.2 O+H .220E+14 0.0 5150. H+O.sub.2 =OH+O .220E+15 0.0 16800. O+ H.sub.2 =OH+H .180E+11 1.0 8900. H+HO.sub.2 =OH+OH .250E+15 0.0 1900. O+HO.sub.2 =O.sub.2 +OH .480E+15 0.0 1000. OH+HO.sub.2 =H.sub.2 O+O.sub.2 .500E+14 0.0 1000. OH+OH=O+H.sub.2 O .630E+13 0.0 1090. HO.sub.2 +NO=NO.sub.2 +OH .343E+13 0.0 -260. H+NO.sub.2 =NO+OH .350E+15 0.0 1500. O+NO.sub.2 =NO+O.sub.2 .100E+14 0.0 600. H+O.sub.2 +M=HO.sub.2 +M .150E+16 0.0 -995. H.sub.2 O/21** NNH+M=N.sub.2 +H+M .200E+15 0.0 30000. NO.sub.2 +M=NO+O+M .110E+17 0.0 66000. NH.sub.3 +M=NH.sub.2 +H+M .480E+17 0.0 93929. O+O+M=O.sub.2 +M .138E+19 -1.0 340. NH.sub.2 +NO=N.sub.2 +H.sub.2 O .910E+20 -2.46 1866. NNH+OH=N.sub.2 +H.sub.2 O .300E+14 0.0 0. NNH+NO=N.sub.2 +HNO .906E+12 0.0 0. ______________________________________ **i.e. A=21 × .15E+16 for H.sub.2 O as "third body" .

Claim 3

Dependent Claim 23 words

The process of claim 1 wherein about 0.4 to 10 moles of ammonia is injected per mole of NO of the combustion effluent.

Claim 4

Dependent Claim 23 words

The process of claim 2 wherein about 1 to 3 moles of ammonia is injected per mole of NO of the combustion effluent.

Claim 5

Dependent Claim 26 words

The process of claim 2 wherein the cooling zone in which the ammonia is injected is cooling at a rate of at least about 1000° K./sec.

Claim 6

Dependent Claim 19 words

The process of claim 4 wherein at least 0.25 volume percent of oxygen is present in the combustion effluent.

Claim 7

Dependent Claim 137 words

In a process for reducing NO concentration of at combustion effluent containing NO and at least 0.1 volume percent oxygen when at least a portion of the combustion effluent is at a temperature within the range of about 1300° K. to 1600° K. and wherein the combustion effluent passes through at least one cooling zone in which it is cooling at a rate of at least about 250° K. per second, the improvement which comprises injecting enough ammonia into the combustion effluent at a point upstream from a cooling zone having a cooling rate of at least about 250° K. where the temperature of the combustion effluents is from about 1300° K. to 1600° K. such that when the combustion effluent reaches said cooling zone it contains at least 0.4 moles of ammonia per mole of NO.

Claim 8

Dependent Claim 137 words

In a process for reducing NO concentration of at combustion effluent containing NO and at least 0.1 volume percent oxygen when at least a portion of the combustion effluent is at a temperature within the range of about 1300° K. to 1600° K. and wherein the combustion effluent passes through at least one cooling zone in which it is cooling at a rate of at least about 250° K. per second, the improvement which comprises injecting enough ammonia into the combustion effluent at a point upstream from a cooling zone having a cooling rate of at least about 250° K. where the temperature of the combustion effluents is from about 1300° K. to 1600° K. such that when the combustion effluent reaches said cooling zone it contains at least 0.4 moles of ammonia per mole of NO.

Claim 9

Dependent Claim 28 words

The process of claim 6 wherein the combustion effluent contains from about 1 to 3 moles of ammonia per mole of NO when it reaches the cooling zone.

Claim 10

Dependent Claim 19 words

The process of claim 6 wherein at least 0.25 volume percent of oxygen is present in the combustion effluent.

Claim 11

Dependent Claim 18 words

The process of claim 6 wherein the ammonia is injected within 10.4 seconds upstream from the cooling zone.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1989-11-24	1990-05-26	1990-11-25	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1993-11-24	1994-05-26	1994-11-25	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1997-11-24	1998-05-26	1998-11-25	$7700.00	Window Closed / Lapsed

Non-catalytic method for reducing the concentration of NO in combustion effluents by injection of ammonia at temperatures greater than about 1300° K.

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