DETAILED ACTION
Claims 1-15 are pending and under consideration in this action.
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-4, 6, 10-11, and 13-15 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by CN108434956 (“Weiping”).
Regarding claim 1, Weiping teaches a method of reducing nitrogen oxides in a flue gas stream from a thermal plant for treatment of municipal solid waste, which is considered to either include domestic waste or to be similar to domestic waste (see e.g. paragraphs [0002] and [0027]). The method includes passing the flue gas through a secondary treatment unit configured for selective, non-catalytic reduction (see e.g. paragraph [0009]). The gas is then treated by ozone injection (see e.g. paragraph [0012]). Finally, the gas is passed through an absorption unit (see e.g. paragraph [0013]). Because the ozone injection is after the SNCR and prior to the absorption unit, the ozone is injected downstream of the secondary treatment unit and upstream of the absorption unit (see e.g. paragraphs [0009]-[0013]).
Regarding claim 2, Weiping teaches that the ammonia concentration is at 40%, which therefore requires determination of the concentration upstream of the ozone injection (see e.g. paragraph [0036]). Weiping further teaches a specific ratio of ozone to nitrogen oxide, which requires determining the nitrogen oxide content of the flue gas upstream of the ozone injection (see e.g. paragraph [0039]).
Regarding claim 3, Weiping teaches a set amount of ammonia is used in the secondary treatment unit which is therefore considered to be set for a base amount of nitrogen oxides (see e.g. paragraph [0036]). The amount of ozone added is based on the amount of nitrogen oxides remaining after the secondary treatment unit, which means that the amount is controlled based on the actual amount of nitrogen oxides remaining and therefore compensates for any short-term fluctuations in the nitrogen concentration (see e.g. paragraph [0039]).
Regarding claim 4, Examiner notes that it is impossible for the pH in the scrubbing unit to be both above and below 7.5. Accordingly, claim 4 is interpreted as requiring either of the pH and ozone correlations to be met. Weiping teaches that the scrubbing unit uses 5% sodium hydroxide, which places the pH greater than 7.5 (see e.g. paragraph [0017]). Weiping teaches that the ratio of ozone to nitrogen oxide is between 1:1 and 2:1, which overlaps with the claimed range (see e.g. paragraph [0018]).
Regarding claim 6, Weiping teaches that the scrubbing unit includes an adsorber (see e.g. paragraph [0040]).
Regarding claim 10, Weiping teaches SNCR using ammonia as a reducing agent (see e.g. paragraph [0016]). It is understood that reduction of nitrogen oxides in an SNCR device results in reduction of nitrogen monoxide to nitrogen and water.
Regarding claim 11, Weiping teaches using a waste heat boiler upstream of the ozone injection (see e.g. paragraph [0055]).
Regarding claim 13, Weiping teaches that nitrogen oxides are converted to dinitrogen pentoxide by the injection of ozone, which is understood to go through an intermediate nitrogen dioxide species (see e.g. paragraph [0039]).
Regarding claim 14, the instant application indicates that any ratio of ozone to nitrogen oxides of less than 1.5 is considered to be substoichiometric (see instant application at paragraph [0029]). Weiping teaches that the ratio of ozone to nitrogen oxides is between 1:1 and 2:1, which means that in some embodiments Weiping teaches using a substoichiometric amount of ozone (see e.g. paragraph [0018]).
Regarding claim 15, Weiping teaches using sodium hydroxide in the adsorption unit (see e.g. paragraph [0017]). As indicated in the instant application, the hydroxide ions from the sodium hydroxide will react with nitrogen oxides to form sodium nitrite and water (see instant application at paragraph [0030]). As such, the method of Weiping is likewise considered to include the formation of sodium nitrite and water by the same mechanism.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-6, 10-11, and 13-15 are rejected under 35 U.S.C. 103 as being unpatentable over Weiping.
Regarding claim 1, Weiping teaches a method of reducing nitrogen oxides in a flue gas stream from a thermal plant for treatment of municipal solid waste, which is considered to either include domestic waste or to be similar to domestic waste (see e.g. paragraphs [0002] and [0027]). The method includes passing the flue gas through a secondary treatment unit configured for selective, non-catalytic reduction (see e.g. paragraph [0009]). The gas is then treated by ozone injection (see e.g. paragraph [0012]). Finally, the gas is passed through an absorption unit (see e.g. paragraph [0013]). Because the ozone injection is after the SNCR and prior to the absorption unit, the ozone is injected downstream of the secondary treatment unit and upstream of the absorption unit (see e.g. paragraphs [0009]-[0013]).
Examiner notes that based on the wording of the claim, it is possible to interpret the claim as requiring only a single scrubbing, absorption, or adsorption unit because the claim uses the term “a” before this limitation. However, even if the claim is interpreted as requiring a sequence of SNCR-ozone treatment-scrubbing, the claim would still be obvious over Weiping. Weiping teaches that the first absorption device after the SNCR device is for the purpose of removing heavy metals, residual nitrogen oxides, sulfides, carbon dioxide and dioxins (see e.g. paragraph [0037]). Per MPEP 2144.04(V)(B), combining separate parts into a single integral device is prima facie obvious as a simple engineering choice. Accordingly, prior to the effective filing date of the invention, it would have been obvious to integrate the first scrubber device of Weiping into the second scrubber device to remove the sulfides, metals, and dioxins in a single device. Doing so would provide the claimed sequence of the method.
Regarding claim 2, Weiping teaches that the ammonia concentration is at 40%, which therefore requires determination of the concentration upstream of the ozone injection (see e.g. paragraph [0036]). Weiping further teaches a specific ratio of ozone to nitrogen oxide, which requires determining the nitrogen oxide content of the flue gas upstream of the ozone injection (see e.g. paragraph [0039]).
Regarding claim 3, Weiping teaches a set amount of ammonia is used in the secondary treatment unit which is therefore considered to be set for a base amount of nitrogen oxides (see e.g. paragraph [0036]). The amount of ozone added is based on the amount of nitrogen oxides remaining after the secondary treatment unit, which means that the amount is controlled based on the actual amount of nitrogen oxides remaining and therefore compensates for any short-term fluctuations in the nitrogen concentration (see e.g. paragraph [0039]).
Regarding claim 4, Examiner notes that it is impossible for the pH in the scrubbing unit to be both above and below 7.5. Accordingly, claim 4 is interpreted as requiring either of the pH and ozone correlations to be met. Weiping teaches that the scrubbing unit uses 5% sodium hydroxide, which places the pH greater than 7.5 (see e.g. paragraph [0017]). Weiping teaches that the ratio of ozone to nitrogen oxide is between 1:1 and 2:1, which overlaps with the claimed range (see e.g. paragraph [0018]).
Regarding claim 5, Weiping does not explicitly teach that the quantity of ammonia metered into the secondary treatment unit is controlled in accordance with current market prices. However, Weiping teaches that ammonia is not the only reducing agent that can be used, and in particular, urea can alternatively be used (see e.g. paragraph [0016]). Further, although Weiping teaches generally that 40% ammonia or urea can be used, this is explicitly described as a preferable amount, and thus can be varied (see e.g. paragraph [0036]). Accordingly, prior to the effective filing date of the invention, it would have been obvious to one of ordinary skill in the art to vary the amount of ammonia used in the process in order to maximize the economic efficiency of the process based on the price of ammonia. Because the amount of ozone is set according to the amount of NOx remaining in the stream, the amount of ozone injected will also vary based on the amount of ammonia used (see e.g. paragraph [0039]).
Regarding claim 6, Weiping teaches that the scrubbing unit includes an adsorber (see e.g. paragraph [0040]).
Regarding claim 10, Weiping teaches SNCR using ammonia as a reducing agent (see e.g. paragraph [0016]). It is understood that reduction of nitrogen oxides in an SNCR device results in reduction of nitrogen monoxide to nitrogen and water.
Regarding claim 11, Weiping teaches using a waste heat boiler upstream of the ozone injection (see e.g. paragraph [0055]).
Regarding claim 13, Weiping teaches that nitrogen oxides are converted to dinitrogen pentoxide by the injection of ozone, which is understood to go through an intermediate nitrogen dioxide species (see e.g. paragraph [0039]).
Regarding claim 14, the instant application indicates that any ratio of ozone to nitrogen oxides of less than 1.5 is considered to be substoichiometric (see instant application at paragraph [0029]). Weiping teaches that the ratio of ozone to nitrogen oxides is between 1:1 and 2:1, which means that in some embodiments Weiping teaches using a substoichiometric amount of ozone (see e.g. paragraph [0018]).
Regarding claim 15, Weiping teaches using sodium hydroxide in the adsorption unit (see e.g. paragraph [0017]). As indicated in the instant application, the hydroxide ions from the sodium hydroxide will react with nitrogen oxides to form sodium nitrite and water (see instant application at paragraph [0030]). As such, the method of Weiping is likewise considered to include the formation of sodium nitrite and water by the same mechanism.
Claims 7 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Weiping as applied to claim 1 above, and further in view of CN212142070 (“Yunjie”).
Regarding claim 7, Weiping teaches the limitations of claim 1 as described above, but does not specifically teach the concentration of nitrogen oxides after reduction in the secondary treatment unit. However, Yunjie teaches a similar selective, non-catalytic reduction system for removing nitrogen oxides from flue gas of waste incineration (see e.g. paragraph [0056]). Yunjie teaches that, prior to the SNCR treatment, the nitrogen oxide content is about 300 mg/m3, and that the traditional SNCR efficiency is about 35%, which would place the nitrogen oxide concentration after traditional SNCR within the claimed range (Id.). Accordingly, prior to the effective filing date of the invention, it would have been obvious to use a traditional SNCR system as taught by Yunjie for the SNCR system of Weiping because Weiping does not teach that the SNCR system needs to perform at a higher level than normal. Doing so would result in a nitrogen oxide concentration in the secondary treatment unit within the claimed range. Neither Weiping nor Yunjie teach that there is any appreciable ammonia concentration downstream of the secondary treatment unit, and as such, it is assumed to be under 10 mg/m3.
Regarding claim 9, Weiping teaches that an injection of ammonia or urea into the flue gas is carried out either in or upstream of the secondary treatment unit (see e.g. paragraph [0016]). Weiping does not teach a specific temperature to use in the SNCR unit. However, Yunjie teaches that traditional selective non-catalytic reduction using ammonia takes place at a temperature of 850-1050 °C, which is within the claimed range (see e.g. paragraph [0008]). Accordingly, prior to the effective filing date of the invention, it would have been obvious to use a traditional SNCR method as taught by Yunjie for the SNCR portion of Weiping because Weiping does not teach that the SNCR system needs to perform at a higher level than normal. Doing so would result in a temperature within the claimed range.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Weiping in view of Yunjie as applied to claim 7 above, as evidenced by German Federal Environmental Agency, Beckmann, “Description of different techniques and their development potentials for reducing nitrogen oxides in the exhaust gas of waste incineration plants”, text 71/2011, 2011 (“Beckmann”, cited in IDS of 4/9/24).
Regarding claim 8, Weiping in view of Yunjie teach the limitations of claim 7 as described above. Weiping does not actually provide the final nitrogen oxide concentration after reaction with ozone. However, Weiping states that the emissions are far below the applicable EU regulations (see e.g. paragraph [0027]). As shown in Beckmann, the EU regulations require nitrogen oxide emissions below 100 mg/m3 (see e.g. Beckmann at page 2, first paragraph, starting “In the further…”). Accordingly, it is understood that the system of Weiping results in a nitrogen oxide content of less than 100 mg/m3, and thus within the claimed range.
Claim 12 is rejected under 35 U.S.C. 103 as being unpatentable over Weiping as applied to claim 11 above, and further in view of CN 111167275 (“Qingtao”).
Regarding claim 12, Weiping teaches the limitations of claim 11 as described above, but does not provide the actual temperature prior to ozone oxidation. However, Qingtao teaches a similar SNCR/ozone oxidation system for removal of nitrogen oxides in a flue gas (see e.g. paragraph [0018]). Qingtao teaches that the oxidation portion occurs at a temperature of between 50-120 °C, which is within the claimed range (Id.). Accordingly, prior to the effective filing date of the invention, it would have been obvious to one of ordinary skill in the art to cool the flue gas to a temperature of between 50-120 °C prior to ozone oxidation because Qingtao teaches that this temperature range is the usual range for the step.
Conclusion
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/E.S.S./Examiner, Art Unit 1736
/STUART L HENDRICKSON/Primary Examiner, Art Unit 1736
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