DETAILED 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 Status
The claims move former Claim 2 into Claim 1.
Response to Arguments
Applicant's arguments filed 12/9/25 have been fully considered but they are not persuasive.
The remarks argue on pages 9-10, the following:
With respect to a rejection under §103, "a proper analysis under § 103 requires, inter alia, consideration of two factors: (1) whether the prior art would have suqqested to those of ordinary skill in the art that they should make the claimed composition or device, or carry out the claimed process; and (2) whether the prior art would also have revealed that in so making or carrying out, those of ordinary skill would have a reasonable expectation of success" (emphasis added). In re Vaeck, 947 F.2d 488 (Fed. Cir. 1991). Neither is present in the Rejection currently of record, and Applicant therefore traverses the Rejection.
First, Applicant notes that the Office concedes that Cerea does not teach that the oxygen used in the bleacher unit is made from a high-pressure water electrolyzer, that provides high pressure oxygen-rich gas as the stripping medium in the bleacher. Nevertheless, the Office cites Zhu as allegedly remedying the deficiencies of Cerea.
Zhu relates to a dual-pressure plant for the production of nitric acid, comprising the compression of the NOx containing gases between the ammonia convertor and the absorber unit (see feature 35 "nitrogen oxide gas compressor" in Figure 1). It is further noted that the Zhu's plant does not comprise an air compressor (Zhu, Fig 1) and even teaches against the presence of an air compressor, in that in order to prevent NOx emissions, nitrogen should be prevented from entering the process system; in particular by using oxygen instead of ambient air in the ammonia oxidation process. Accordingly, Zhu requires multiple structural modifications to arrive at the claimed subject matter.
The plant described in claim 1 of the current application differs from the disclosure of Zhu in that the water electrolyser is pressurized to provide a high-pressure oxygen-rich gas at 9 to 30 bar. Zhu teaches that the oxygen from the electrolyzed water at a normal pressure 0.11 Mpa (i.e., 1.1 bar) is compressed in an oxygen compressor 30 to provide a compressed oxygen at a pressure of 0.42-0.45 MPa (i.e., 4.2-4.5 bar). The compressed oxygen is thereafter cooled to 300C or below through the cooler 31 before sending it to the bleacher 32. A skilled person would understand that cooling gas does not inherently change the regulated pressure, but if the gas is in a fixed volume (no pressure control) the pressure will fall in proportion to temperature (applying gas law PV= nRT). Therefore, unless there is a change in volume or the amount of gas, the pressure will not be affected by temperature changes below 30°C. Thus, the oxygen after cooling would remain at an identical pressure of 0.42-0.45 Mpa (i.e., 4.2-4.5 bar). Moreover, the bleacher 32 of Zhu seems to be operating at 4.4 bar.
In contrast to the Office's position, the present application mentions multiple advantages and effects of the claimed subject-matter (see e.g., the section between p.4, line 29 and p.5, line 13). In particular, due to the high-pressure electrolyser providing pressurized oxygen, there is no need for an air compressor for pressurizing the stripping medium. Accordingly, the air compressor only pressurizes primary air for the convertor, thus requiring the air compressor to produce less work, which also allows it to handle an increased (convertor) throughput. A higher nitric acid production can thus be achieved without replacing the air and NOx compressors. In addition, as it requires less power to pump water than to compress gas, there is a significant overall energy savings as well.
Thus, for all the reasons above, Applicant submits the a proper prima facie case of Obviousness has not been made out, in that the combined references do not teach, suggest, or disclose all the elements of the present claims, and in any event there would be no motivation or reasonable expectation of success in modifying the references as suggested by the Office.
The remarks are respectfully not persuasive. Zhu shows use of an air compressor at 30 in Figure 30. Therefore, it is respectfully contended that Zhu does teach this feature. As to the current Application differing from the Zhu reference, this is respectfully not persuasive. First, the claims are apparatus claims. Therefore, as long as the device is capable of performing this pressurizing step, this meet the feature. Second, Applicant argues specific pressure features that are not claimed. That is, Claim 1 describes high pressure oxygen-rich gas in fluid communication with the bleacher unit, but does not recite a specific pressure range. Claims 6 and 10 also do not recite this feature. Furthermore, use of a high pressure electrolyzer to produce oxygen is known in the art. For example, Hahn (WO 2011/012507) describes use of this (see abstract). It is respectfully argued that the air compressor of Zhu does not compress air from just a converter, but from an electrolyzer (see reference, page 18, second para).
Claim Objections
Claim 13 is objected to because of the following informalities: Claim 13 depends from Claim 2, which is now canceled. Claim 13 will be treated as being dependent on Claim 1.
Appropriate correction is required.
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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1, 4, 5, 6, 9, 10, 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cerea (WO 2018/162150) and in view of Zhu (CN 109516445), EPO translation and in view of Yang (CN 106586985).
Cerea describes a plant and method for its use (title and abstract). The process and device employ an air compressor 2, an air-ammonia mixer 3, a reactor 4, a nitrous gas compressor 5, an absorption tower 6, a bleacher 7, a turbine, a cooler condenser and a tail ga preheater 9a-9c, 9d (page 9, lines 4-8).
The air compressor is “operable to pressurize air to a pressure range from 2-6 bar”.
The air-ammonia mixer 3 can be considered a converter “operable to be fed with a stream of an ammonia/pressurized air mixture at how pressure to oxidize the ammonia and to produce an LP gaseous NOx gas stream/steam mixture, comprising water and NO”. The pressure of the converter is not disclosed. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the pressure is at least ambient pressure, which can be considered a low pressure.
Downstream of the air-ammonia mixer is a reactor 4. There is also a nitrogen gas compressor at 5, which operates at an elevated pressure (page 10, lines 14-17). This compressor is operable to “elevate the pressure of a gaseous NOx stream from a low pressure to a pressure ranging from 9-16 bar, resulting in a JP gaseous NOx stream”.
The system includes an absorption tower 6 (page 9, lines 4-8). The absorption unit is operated at an elevated pressure of 9-16 bar (page 11, lines 22-23). The absorption tower is “operable to react the nitrogen oxides contained in the HP gaseous NOx stream with water, wherein the absorber unit provides an output product stream containing nitric acid and dissolved nitrogen oxides, and a tail gas”.
The system also includes a bleacher unit 7 (page 9, lines 4-8). This bleacher unit would be “operable to strip dissolved nitrogen oxides away from the output product stream with a stripping medium, providing a stripped nitric acid stream and a NOx loaded stripping gas”.
Cerea explains that this bleacher unit operates at the same pressure as the absorption tower, which is a pressure of about 9-16 bar (page 11, lines 21-23).
The bleacher unit receives air from air stream 16 to strip NOx (page 11, lines 7-8).
A second bleacher unit 37 may be installed (page 12, line 2 and page 11, lines 20-25). The stream that is stripped (see Fig. 2, 41) is then recycled back to reactor 6 (see Fig. 2, 41, to 24 to 26).
Cerea explains that the stream 19, NOx-loaded air stream, is recycled to the nitrous gas compressor 5 (page 11, lines 7-10).
As to feeding NOx stripped from a bleacher to the downstream end of a compressor, Cerea teaches that that some of the NOx-including stripped gas is recycled back to the system (Fig. 2, 24), which is downstream of compressor 2.
The gas stream from the air compressor 42 is supplied to the HP bleacher 37 (page 12, lines 13-15).
Cerea does not teach that the oxygen used in the bleacher unit is made from a high-pressure water electrolyzer, that provides high pressure oxygen-rich gas as the stripping medium in the bleacher.
Zhu describes a method of making nitric acid using a water electrolysis method (abstract and title). In their system, oxygen is generated by electrolyzing water at a pressure and then feeding that oxygen to an oxygen compressor 30, which is then fed to a bleaching tower 32 (page 18, lines 11-13).
Use of a electrolysis system uses clean energy (para. 2). Furthermore, producing oxygen in the prior art can have issues when preventing nitrogen from entering the process (para. 4).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a pressurized water electrolysis system to produce compressed oxygen to be fed to a bleaching tower, as taught by Zhu for use with the process of making nitric acid of Cerea because this method employs clean energy and reduces nitrogen contaminants in the oxygen.
As to the oxygen vol %, since the claims are device claims, the same structure would be capable of having the same compounds.
As to Claims 4 and 10, Cerea teaches that between the high pressure bleacher and the lower pressure bleacher, the stream is partially flashed in a valve 31 (page 11, lines 3-6, page 12, line 9). The valve can be considered a flash vessel. The reference does not specifically teach that the valve has an inlet for the stripped nitric acid stream or an outlet, but it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the entrance of the valve can be considered an inlet and the stream coming out of the valve can be considered an outlet. The stream from the bleacher unit is then fed upstream and then passed to the NOx compressor 5 (Fig. 2).
As to Claim 5, Cerea teaches that there are two bleacher units (Fig. 2, 37 and 7). One is a high pressure bleacher (page 11, lines 21-25) and the other is a low pressure bleacher (page 11, line 25). Each bleacher has an inlet and an outlet (see Fig. 2). After the outlet of the second bleacher, the gas stream is recycled upstream of the NOx gas compressor (Fig. 2, 19). As for the method steps and compositions, to include the HP oxygen rich gas stream, the courts have held that “ where the claimed and prior art products are identical or substantially identical in structure or composition, or are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). “When the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not.” In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990). Therefore, the prima facie case can be rebutted by evidence showing that the prior art products do not necessarily possess the characteristics of the claimed product. In re Best, 562 F.2d at 1255, 195 USPQ at 433. See also Titanium Metals Corp. v. Banner, 778 F.2d 775, 227 USPQ 773 (Fed. Cir. 1985) (Claims were directed to a titanium alloy containing 0.2-0.4% Mo and 0.6-0.9% Ni having corrosion resistance. A Russian article disclosed a titanium alloy containing 0.25% Mo and 0.75% Ni but was silent as to corrosion resistance. The Federal Circuit held that the claim was anticipated because the percentages of Mo and Ni were squarely within the claimed ranges. The court went on to say that it was immaterial what properties the alloys had or who discovered the properties because the composition is the same and thus must necessarily exhibit the properties.).
See also In re Ludtke, 441 F.2d 660, 169 USPQ 563 (CCPA 1971) (Claim 1 was directed to a parachute canopy having concentric circumferential panels radially separated from each other by radially extending tie lines. The panels were separated “such that the critical velocity of each successively larger panel will be less than the critical velocity of the previous panel, whereby said parachute will sequentially open and thus gradually decelerate.” The court found that the claim was anticipated by Menget. Menget taught a parachute having three circumferential panels separated by tie lines. The court upheld the rejection finding that applicant had failed to show that Menget did not possess the functional characteristics of the claims.); Northam Warren Corp. v. D. F. Newfield Co., 7 F. Supp. 773, 22 USPQ 313 (E.D.N.Y. 1934) (A patent to a pencil for cleaning fingernails was held invalid because a pencil of the same structure for writing was found in the prior art.) See MPEP § 2112.01
As to Claim 9, Zhu describes feeding oxygen at room temperature (see page 10, lines 6-8).
As to Claim 11, the rejection of Claim 6 is reiterated here. Cerea teaches a first bleacher 37 and a second bleacher 7, where one is a high pressure bleacher and the other a lower pressure bleacher, the high pressure bleacher is operated at the same pressure as the absorption tower (page 11, lines 20-25). The stripped gas is recycled (see Fig. 2, 20) and then sent to the adsorption tower 6 (see Fig. 2, 20 and 6).
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cerea, Zhu and Yang as applied to claim 6 above, and further in view of Nakanori (JP 2004/084042).
Cerea, Zhu and Yang teach use of oxygen, but does not describe the volume percent.
Zhu describes generating oxygen from water electrolysis (see above). Zhu does not specifically state what the oxygen vol % generated is.
Nakanori teaches a water electrolysis device (title) used to generate hydrogen and oxygen (para. 1). The product made produces a oxygen to hydrogen ratio of 2:1 from the water electrolysis (para. 7). This is about a 33%, which is greater than the 21vol %. This is calculated based on volume (para. 12, para. 2, “inner volume of the hydrogen gas. . . inner volume of the oxygen gas”).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to produce oxygen in a volume of 33%, as taught by Nakanori for use in the electrolysis of water to generate oxygen, as taught by Zhu in the bleacher unit of Cerea, Zhu and Yang because Zhu describes use of electrolysis to generate oxygen that is fed to a bleaching tower.
Claim(s) 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cerea, Zhu and Yang as applied to claim 1 above, and further in view of Kong (CN 102530893).
The references describe use of HP oxygen, but does not describe that the oxygen has 95% vol oxygen.
Kong describes a method of making nitric acid (see “Description”, para. 1). The process uses a bleacher tower that feeds an air stream with 75 to 99% of air to the beaching tower (“Description”, para. 1).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ an air stream with 75-99% of air to the bleacher unit, as taught by Kong for use with the HP air stream fed to the bleacher of Cerea, Zhu and Yang because this volume of air is known to be effective for use in a bleacher unit.
Claim(s) 14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cerea, Zhu, Yang and Nakanori as applied to claim 7 above, and further in view of Kong (CN 102530893).
The references describe use of HP oxygen, but does not describe that the oxygen has 95% vol oxygen.
Kong describes a method of making nitric acid (see “Description”, para. 1). The process uses a bleacher tower that feeds an air stream with 75 to 99% of air to the beaching tower (“Description”, para. 1).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ an air stream with 75-99% of air to the bleacher unit, as taught by Kong for use with the HP air stream fed to the bleacher of Cerea, Zhu, Yang and Nakanori because this volume of air is known to be effective for use in a bleacher unit.
Claim(s) 15 is/are rejected under 35 U.S.C. 103 as being unpatentable over Cerea, Zhu and Yang as applied to claim 9 above, and further in view of Huang (CN 103112835).
The references do not describe heating the HP oxygen gas to a temperature of 50-120 degrees C.
Huang describes a method of making nitric acid (title). The method employs a bleaching unit that feeds “bleaching air” into the unit at a temperature of higher than 60 degrees C (Description, para. 1).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to heat the bleaching air to a temperature of 60 degrees C, as taught by Huang for use with the air fed to the bleaching unit of Cerea, Zhu and Yang because air heated to this temperature is effective for use in stripping gas fed to these bleaching units when used in a nitric acid production system.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHENG HAN DAVIS whose telephone number is (571)270-5823. The examiner can normally be reached 9-5:30.
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/SHENG H DAVIS/Primary Examiner, Art Unit 1732 February 4, 2026