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
Claims 1-15 were filed on 1/19/2024. In a preliminary amendment filed on the same day, claims 1-15 were canceled and claims 16-30 were filed. Claims 16-30 are pending.
Priority
The instant application was filed on 1/19/2024 and claims the benefit of priority to:
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, see filing receipt dated 6/20/2024. Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Specification
The specification is objected to as failing to provide proper antecedent basis for the claimed subject matter. See 37 CFR 1.75(d)(1) and MPEP § 608.01(o). Correction of the following is required: there is no antecedent basis for the limitation “mobile heating units” in claim 27.
Claim Objections
Claims 1 and 29 are objected to because of the following informalities:
In step c) of claim 1, the word “ending” is misspelled as “cending” at the beginning of the limitation.
In claim 29, there is a verb missing in line 2 between “system” and “not more than”.
Appropriate correction is required.
Claim Rejections - 35 USC § 112(b)
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 29 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 29 recites the limitation "the cooling medium" in line 3. There is insufficient antecedent basis for this limitation in the claim.
Claim Rejections - 35 USC § 103
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 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) 16-26 and 30 is/are rejected under 35 U.S.C. 103 as being unpatentable over Rossi (“Phosgene formation via carbon monoxide and dichlorine reaction over an activated carbon catalysts: Reaction testing arrangements” Applied Catalysis A, published online 2/13/2020, p. 117467) in view of GB 849929 (GB ‘929, published on 9/28/1960, of record in the IDS filed on 4/11/2026).
Applicant claims a process for producing phosgene from chlorine (Cl2) and carbon monoxide (CO) over an activated carbon catalyst which has been freed from moisture.
Rossi describes an apparatus to investigate the synthesis of phosgene from the reaction of carbon monoxide and dichlorine (aka chlorine gas Cl2) over an activated carbon catalyst. See abstract. Rossi teaches that “the reactor was typically charged with 125 mg of catalyst of size fraction 250−500 μm (Endcotts sieves). The catalyst was placed on a sinter in the middle of the reactor and the reactor inlet was plugged using quartz wool (Sigma). The density of the ground catalyst was 0.805 g ml−1. For activation, the catalyst sample was dried overnight at 383 K in flowing nitrogen (flow rate=20 ml min−1); this procedure removed any absorbed water. The total flow of the exit gas was kept constant at 159 ml min−1. Standard flow conditions were as follows: 5 ml min−1 CO, 4 ml min−1 Cl2, 50 ml min−1 N2 (carrier gas) and 100 ml min−1 N2 (diluent post-reactor), corresponding to a gas hourly space velocity (GHSV) [11] of 22,838 h−1. The initial flow rate (A0) was determined by passing the gas flow over a by-pass line contained within the oven that contained ground quartz (250−500 μm) of comparable volume to the reactor containing catalyst. Once the desired temperature had been attained, the catalyst was exposed to reagents for 20 min before measurements were taken. For variable temperature measurements, 20 min were allowed for the catalyst/reagents to equilibrate thermally before spectroscopic measurements were taken.”. See section 2.3 on p. 3.
Thus, Rossi teaches instant steps a, c, and d, wherein the inert gas is nitrogen (N2-claim 20) and the catalyst bed and inert gas are heated at 383 K (110°C, falling within the range of claim 25), during the drying process. Also see MPEP 2144.05. Rossi also teaches that the drying is carried out in the phosgene production reactor (claim 17) after the catalyst installation and before startup (claims 18-19).
Rossi does not explicitly teach that the residual moisture content of the catalyst is determined before the drying step.
GB ‘929 is directed toward a method and apparatus for catalyst activation, in particular for activating solid particular polymerization catalysts comprising metallic oxides, especially chromium oxide. See p. 1, lines 1-18. GB ‘929 teaches that “in their simplest form, catalyst activation processes comprise drying and heating air and passing it through a catalyst bed at a constant rate until the catalyst reaches the desired temperature, at which point the temperature of the activating air is stabilized and the catalyst is held at the activation temperature for the proper length of time”. GB ‘929 also teaches that “one of the objects of such a treatment is the removal of moisture from the catalyst, since water is a catalyst poison in many applications”. See p. 1, lines 35-55. GB ‘929 teaches that the apparatus comprises a dew point indicator, which enables accurate control of catalyst activation time. See p. 2, lines 54-56 and p. 5, lines 15-60, which refer to element 59 of the Figure. GB ‘929 teaches that the dew point of the circulating air is measured at a point of the circulating air is measured at a point upstream from the point at which the make-up air enters the recycle stream and said stream is cooled when the dew point drops to 0°F or below. See claim 12. Thus, GB ‘929 teaches that the dew point of an off-gas comprising an inert gas (including air-claim 20) and moisture, can be used to measure the moisture level of a catalyst during a catalyst drying/activating step (claims 16 and 22).
It would have been prima facie obvious to combine the teachings of Rossi and GB ‘929 with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill would have been motivated to measure the dew point of the off-gas comprising an inert gas and water in the process/apparatus of Rossi because Rossi teaches that moisture should be fully removed from the activated carbon catalyst and dries the catalyst with heating in the presence of an inert gas and GB ‘929 teaches that dew-point measurements are a well-known way to accurately monitor the content of water of the catalyst during a drying/activating step involving heating the catalyst in the presence of an inert gas. Therefore, measuring the dewpoint of the off-gas of Rossi, as taught by GB ‘929, will predictably enable the skilled artisan to more accurately measure the content of water left on the catalyst. Also see MPEP 2143(I)(A).
Regarding claims 21 and 23, as evidenced by example 2 of the specification as filed on p. 19, the dewpoint of pure nitrogen gas is -66°C. Rossi teaches that the activated carbon catalyst is heated in the presence of nitrogen gas until all the absorbed water has been removed. Therefore, if the dewpoint of the off-gas were being monitored, as suggested by GB ‘929, the dewpoint should fall to as close to -66°C as possible to ensure full removal of moisture from the catalyst of Rossi. Further, GB ‘929 teaches that the chromium oxide polymerization catalyst is dried in the presence of air as the inert gas until the dewpoint of the air leaving the catalyst (the off-gas) is -40°F (-40°C) to produce a substantially dehydrated catalyst. See p. 6, lines 7-25. Both of these desired dewpoints indicate that the dewpoint of the off-gas during drying/activating of catalysts fall within or encompass the ranges of claims 21 (inert gas can have a dewpoint of at least -35°C) and 23 (dewpoint of off-gas after drying is at least down to a dewpoint of -20°C). Also see MPEP 2144.05.
Regarding claim 24, Rossi teaches that the gases from the reactor are scrubbed before being vented to the atmosphere. See Fig. 1 on p. 2 and discussion thereof in section 2.2 on p. 2-3.
Regarding claim 26, though Rossi teaches that the catalyst bed and inert gas are heated at 383 K (110°C), which falls within the claimed range, Rossi appears to only teach an oven heating element in the reactor. See Fig. 1 on p. 2 and discussion thereof in section 2.2 on p. 2-3. Rossi does not appear to explicitly teach pre-heating the gas before it enters the reactor and is heated by the oven. GB ‘929 teaches that the apparatus in their catalyst activation system includes an air heating means. See p. 2, lines 17-46, p. 3, lines 18-41, and element 41 in the Figure as discussed on p. 4, lines 9-21. Therefore, it would have been prima facie obvious to include a pre-heater for the inert gas in the process of Rossi as taught by GB ‘929 to predictably arrive at a process wherein the inert gas is heated before being fed to the activation/drying reaction in the reactor. Also see MPEP 2143(I)(A).
Regarding claim 30, Rossi teaches that for activation, the nitrogen flow rate was 20 ml/min and that the total flow of the exit gas was kept constant at 159 ml/min. See section 2.3 on p. 3. Rossi does not explicitly teach that volume flow rate. GB ‘929 generally teaches “a minimum bed depth is preferred for any given quantity of catalyst to allow a greater cross-section and hence greater gas volume flow rate which in turn reduces activation cycle time”. See p. 4, lines 68-72. Therefore, it would have been prima facie obvious to modify the volume flow rate to arrive at the claimed method based on routine optimization because Rossi and GB ‘929 teach that flow rates are results effective variables for the activation/drying step and generally held constant. Also see MPEP 2144.05.
Claim(s) 24-29 is/are rejected under 35 U.S.C. 103 as being unpatentable over Rossi (“Phosgene formation via carbon monoxide and dichlorine reaction over an activated carbon catalysts: Reaction testing arrangements” Applied Catalysis A, published online 2/13/2020, p. 117467) in view of GB 849929 (GB ‘929, published on 9/28/1960, of record in the IDS filed on 4/11/2026), as applied to claims 16-26 and 30 above and further in view of Geng (CN102092713A, published on 6/15/2011, of record in the IDS filed on 4/11/2026). A machine translation of Geng is provided with the instant OA.
Neither Rossi nor GB ‘929 explicitly teach the use of a mobile heating unit for the heating of the inert gas used for drying (claim 27); wherein the catalyst is preheated to the desired temperature with the aid of the reactor cooling system (claim 28); and wherein the heating of the catalyst with the aid of the reactor cooling system is not more than up to a temperature 10°C below the boiling temperature of the cooling medium of the reactor cooling system at standard pressure (claim 29).
Geng is directed toward a method for continuously preparing phosgene which is analogous to the process of Rossi and GB ‘929. Geng teaches “a method for reacting with carbon monoxide by chlorine to produce the phosgene, involve the method for making chlorine and carbon monoxide produce the phosgene in the shell of pipe reactor by exothermal reaction in presence of absorbent carbon catalyst specifically. Wherein after chlorine is mixed with excessive carbon monoxide in mixing basin M1, enter shell and tube reactor C1, react and produce the phosgene under the influence of absorbent carbon catalyst, pass guard reactor C2, guarantee chlorine and reaction are complete; The heat that the reaction produces is derived by the round-robin 60 ℃ cooling water system of closed path, the gaseous phosgene produced is through W1, after W2 two-stage is condensed, cooled, enters phosgene gas-liquid separator tank B2, the uncooled gas enters tail gas absorber K1, absorb the phosgene included in the end gas and reclaim and use with-5 ℃ methylbenzene.” See abstract.
The apparatus for the process is shown in the Figure:
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, wherein B1 is the Cl2 preheater; M1 is a CO, Cl2 mixer, C1 is the phosgene synthesis reactor; C2 is the phosgene protection reactor; W1 is a phosgene condenser; W2 is a phosgene cooler; B2 is a phosgene gas-liquid separation tank; and K1 is the tail gas absorption tower. See lines 422-425 of the translation.
Regarding claim 27, as discussed with claim 26, the combination of Rossi and GB ‘929 each the pre-heating temperature of the inert gas used for drying, but not that the heating is performed with mobile heating units. Geng teaches a detached pre-heating unit (B1) which can be used to pre-heat gaseous Cl2.
Regarding claims 28-29, Geng teaches that the phosgene reactor (C1) comprises a 60°C closed-loop heat transfer system which uses cooling water to dissipate the heat of the phosgene reaction.
It would have been prima facie obvious to combine the teachings of Rossi, GB ‘929, and Geng to arrive at the instantly claimed processes with a reasonable expectation of success before the effective filing date of the claimed invention. A person of ordinary skill would have been motivated to use a mobile heating unit to heat the inert gas of the combined process of Rossi and GB ‘929 to arrive at instant claim 27, because Geng teaches that detached (mobile) heating units are known in the art for pre-heating gases in the art. Therefore, using a well-known apparatus for its intended use is not inventive. Also see MPEP 2143(I)(A) and MPEP 2144.04(V). A person of ordinary skill would have been motivated to use a cooling medium of the reactor cooling system to pre-heat the catalyst as required by claims 28 and 29 because Geng teaches that such reactors are known and can be predictably substituted for the oven reactor of the combined process of Rossi and GB ’929. The substitution of the reactor of Geng for the oven reactor in the combined process of Rossi and GB ‘929 would predictably lead to a more efficient process wherein heat generated during the phosgenation reaction can be recovered and fed back to the reactor for any pre-heating steps using the closed-loop heat transfer arrangement. Also see MPEP 2143(I)(B). With further respect to claim 29, Geng teaches that the heat transfer fluid is water (which has boiling point of 100°C) and that the closed loop operates at 60°C, which is 40°C less than the boiling temperature and meets the limitations of the claimed range. Also see MPEP 2144.05.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AMY C BONAPARTE whose telephone number is (571)272-7307. The examiner can normally be reached 11-7.
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/AMY C BONAPARTE/ Primary Examiner, Art Unit 1692
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