IFP ENERGIES NOUVELLES

Patent Trials and Appeals Board

Feb 28, 2022

2021001680 (P.T.A.B. Feb. 28, 2022)

UNITED STATES PATENT AND TRADEMARK OFFICE UNITED STATES DEPARTMENT OF COMMERCE United States Patent and Trademark Office Address: COMMISSIONER FOR PATENTS P.O. Box 1450 Alexandria, Virginia 22313-1450 www.uspto.gov APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO. 14/909,326 02/01/2016 Florent GUILLOU PET-3066 3835 23599 7590 02/28/2022 MILLEN, WHITE, ZELANO & BRANIGAN, P.C. 2200 CLARENDON BLVD. SUITE 1400 ARLINGTON, VA 22201 EXAMINER NASSIRI MOTLAGH, ANITA ART UNIT PAPER NUMBER 1734 NOTIFICATION DATE DELIVERY MODE 02/28/2022 ELECTRONIC Please find below and/or attached an Office communication concerning this application or proceeding. The time period for reply, if any, is set in the attached communication. Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the following e-mail address(es): docketing@mwzb.com PTOL-90A (Rev. 04/07) UNITED STATES PATENT AND TRADEMARK OFFICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Ex parte FLORENT GUILLOU, FABIEN PORCHERON, KARIN BARTHELET, ARNAUD BAUDOT, YANN LEPINE, and CLOTILDE JUBIN Appeal 2021-001680 Application 14/909,326 Technology Center 1700 Before ADRIENE LEPIANE HANLON, JEFFREY B. ROBERTSON, and JAMES C. HOUSEL, Administrative Patent Judges. HOUSEL, Administrative Patent Judge. DECISION ON APPEAL STATEMENT OF THE CASE Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the Examiner’s decision to reject claims 1, 2, 4-18, and 202. See Final Office Action (“Final Act.”) dated February 26, 2020. We have jurisdiction under 35 U.S.C. § 6(b). We REVERSE. 1 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. Appellant identifies IFP Energies Nouvelles as the real party in interest. Appeal Brief (“Appeal Br.”) filed July 20, 2020, 1. 2 Pending claim 19 is allowed. Final Act. 2. Appeal 2021-001680 Application 14/909,326 2 CLAIMED SUBJECT MATTER The invention recited in the claims on appeal relates to a process for capturing a heavy metal contained in a moist gas by integrating a heat pump cycle to dehumidify the gas. Specification (“Spec.”) filed February 1, 2016, 1:1-6. The process is shown in Figure 1, reproduced below. Fig. 1, showing a block diagram of a process for capturing a heavy metal Figure 1, above, shows the process for the reduction of the partial pressure of water vapor of a moist gas. Id. at 7:17-18. Moist gas, such as a gaseous hydrocarbon effluent, is fed via conduit 100 to heat exchanger 1000, which cools the gas. Id. at 7:1-3, 8:12-28. The cooled gas is then fed to gas-liquid separator 2000 (such as a coalescer) which separates condensed liquid 200 composed mostly of water from gaseous effluent stream 103. Id. at 9:8-20. The gaseous effluent stream flows to heat exchanger 1002, which heats this stream, and then fed to heavy metal guard bed 3000, which captures heavy metal from the gaseous effluent. Id. at 10:7-8. The heat exchange at heat exchangers 1000, 1002 uses a heat transfer fluid flowing, preferably in Appeal 2021-001680 Application 14/909,326 3 counter-current mode to the gaseous effluent, in a heat pump system which compresses and decompresses the heat transfer fluid with a compressor 4000 and decompressor 5000, respectively. Id. at 10:28-30, 11:7-9. Claim 1, reproduced below from the Claims Appendix to the Appeal Brief, is illustrative of the claimed subject matter: 1. A process for capturing at least one mercury or arsenic heavy metal, contained in a gaseous hydrocarbon effluent comprising water vapor, comprising: a) cooling (1000) the gaseous hydrocarbon effluent by heat exchange with a heat transfer fluid produced in e) in order to obtain a gas cooled 2 to l0°C to a temperature Tf, the heat transfer fluid being vaporized during a); b) separating (2000) at least a portion of condensed water contained in the cooled gas obtained in a) in a manner such as to obtain a gas which is depleted in water and a liquid stream containing water; c) compressing (4000) the vaporized heat transfer fluid obtained from a) in a manner such as to obtain a compressed heat transfer fluid; d) heating (1002) the water-depleted gas by heat exchange with the compressed heat transfer fluid obtained in c) in order to obtain a cooled heat transfer fluid and a gas reheated 2 to l0°C to a temperature Tc, the temperature Tc being determined in a manner such that the reheated moist gas obtained in d) has a relative humidity of less than 75%; e) decompressing (5000) the cooled heat transfer fluid obtained in d), the decompressed heat transfer fluid being recycled to a); f) bringing the reheated gas obtained in d) into contact (3000) with a capture mass for said heavy metal in order to obtain a gas depleted in heavy metal. Appeal 2021-001680 Application 14/909,326 4 Appeal Br. 15 (Claims App’x). REFERENCE(S) The Examiner relies on the following prior art to reject the claims: Name Reference Date Dolan US 3,580,003 May 25, 1971 Fornoff et al. US 3,755,989 Sept. 4, 1973 Yan US 5,248,488 Sept. 28, 1993 Craze US 5,483,801 Jan. 16, 1996 Borray et al. US 5,727,903 Mar. 17, 1998 Grande US 5,928,617 July 27, 1999 Flammang et al. US 2010/0018228 A1 Jan. 28, 2010 Bresler et al. US 2012/0000359 A1 Jan. 5, 2012 Briglia et al. US 2012/0167763 A1 July 5, 2012 Leta et al. US 2012/0308456 A1 Dec. 6, 2012 REJECTION(S) The Examiner maintains, and Appellant requests our review of, the following rejections under 35 U.S.C. § 103: 1. Claims 1, 2, 9-11, 13, 14, 18, and 20 as unpatentable over Fornoff in view of Flammang and Grande; 2. Claims 4, 5, and 8 as unpatentable over Fornoff in view of Flammang and Grande, and further in view of Briglia; 3. Claims 6 and 7 as unpatentable over Fornoff in view of Flammang and Grande, and further in view of Bresler; 4. Claim 9 as unpatentable over Fornoff in view of Flammang and Grande, and further in view of Dolan; 5. Claim 12 as unpatentable over Fornoff in view of Flammang and Grande, and further in view of Leta; 6. Claim 15 as unpatentable over Fornoff in view of Flammang and Grande, and further in view of Yan and Borray; and Appeal 2021-001680 Application 14/909,326 5 7. Claims 16 and 17 as unpatentable over Fornoff in view of Flammang and Grande, as evidenced by Craze. OPINION Rejection 1: Obviousness over Fornoff, Flammang, and Grande The Examiner rejects claims 1, 2, 9-11, 13, 14, 18, and 20 as unpatentable over Fornoff in view of Flammang and Grande. Final Act. 3- 10. We limit our discussion below to claim 1, which is dispositive of this rejection on appeal. The Examiner finds that Fornoff discloses a mercury capture process from a gas containing water vapor substantially as recited in claim 1, except for use of a heat pump cycle (heat transfer fluid for cooling/heating the gas is cyclically compressed to then heat the gas, followed by decompression to cool the gas) and that the gas is a gaseous hydrocarbon effluent. Final Act. 3-4, 6. For the heat pump cycle, the Examiner finds that Flammang teaches a bio-renewable thermal energy heating/cooling system, which may be used for any manufacturing process needing both heating and cooling. Id. at 4. The Examiner further finds that Flammang’s system comprises a combination of a compressor and decompressor which saves significant amounts of energy through recycling of thermal energy. Id. The Examiner concludes that it would have been obvious to have modified Fornoff’s process to include a heat pump cycle as taught in Flammang for heating and cooling the gas in order to achieve a more energy efficient process with a reasonable expectation of success. Id. With regard to the gas being a gaseous hydrocarbon effluent, the Examiner finds that Fornoff teaches various gas sources may be treated including by-product streams from a chlor-alkali plant, ore furnace stack Appeal 2021-001680 Application 14/909,326 6 gases, and vent gases from battery disposal or incineration operations. Final Act. 5. However, the Examiner finds that Grande teaches that mercury is present in, and needs to be removed from, a variety of gas sources including H2S-bearing sour gases, natural fuel energy gas, petroleum fuel energy gas, exhaust gas from mercury cell chlor-alkali plants, and emissions from hazardous waste treatment plants. Id. at 6. The Examiner concludes that it would have been obvious to implement Fornoff’s process to remove mercury from a gas known to be contaminated with mercury such as a natural fuel energy gas as taught in Grande with a reasonable expectation of success. Id. The Examiner acknowledges that Fornoff fails to teach cooling the moist gas 2-10°C to a temperature Tf and heating the gas (after water- depletion) 2-10°C to a temperature Tc. Final Act. 6. However, the Examiner finds that Fornoff teaches cooling the moist gas to a temperature Tf and then heating the gas to a temperature Tc in order to obtain a gas with a desired humidity. Id. The Examiner further finds that Fornoff teaches that because common commercial adsorbents adsorb water and mercury, the adsorbent bed must be sized to have sufficient capacity to adsorb water and still have capacity to adsorb mercury. Id. In addition, the Examiner finds that Fornoff suggests that condensing out the water from the gas is costly. Id. at 7. The Examiner concludes that it would have been obvious to have cooled and heated the gas in Fornoff’s process by 2-10°C “in order to achieve desired mercury adsorption relative to the adsorption bed size and the cost of condensing out the water from the gas prior to adsorption with a reasonable expectation of success.” Id. Appeal 2021-001680 Application 14/909,326 7 Appellant argues that the references fail to teach or suggest the heavy metal capture process of claim 1. Appeal Br. 3. Appellant contends that the claimed cooling of the gas stream of 2-10°C is far smaller than would be necessary to cool Fornoff’s hot effluent to sub-room temperatures of 50- 65°F (10-18°C). Id. Appellant also contends that Fornoff heats the gas stream 30°F (16.7°C), whereas claim 1 recites that the gas stream is heated only 2-10°C. Id. Appellant asserts, therefore, that the claimed heat pump cycle restores heat removed from the gas stream, such that the gas stream is restored to temperature and pressure conditions close to the initial conditions, but with substantially reduced water content. Id. at 4. Moreover, Appellant contends that Flammang does not suggest use of a heat pump system for processes such as Fornoff’s requiring significant temperature changes in the heating and cooling steps. Id. at 5. In contrast, Appellant asserts that “the integration of a heat pump system to the clamed process is particularly efficient when the temperature swing is, contrary to the large reduction necessary in [Fornoff], of 2 to l0°C.” Id. Appellant also argues that Flammang’s heat pump system cannot be simply inserted into Fornoff’s process. Appeal Br. 5. Appellant contends that, unlike the claimed process, Flammang’s system is not used to heat and cool the same gas at the same location. Id. at 5-6. Appellant further contends that because Fornoff’s process employs pressure to condense water, integrating Flammang’s heat pump system into Fornoff’s process would change Fornoff’s strategy by removing the gas compressor. Id. at 6. In addition, Appellant contends that because it was known that heat pump systems are incapable of achieving large, rapid temperature changes, there is no reasonable expectation of success to employ such a system in Fornoff to Appeal 2021-001680 Application 14/909,326 8 create significant temperature changes. Id. Nor is there any reason, according to Appellant, to modify Fornoff’s process to utilize the smaller temperature changes recited in claim 1, in the context of heavy metal capture, such that a heat pump circuit could work. Id. Appellant’s arguments are persuasive of reversible error. The Examiner fails to establish why an ordinary artisan would have reduced both the cooling and the heating of Fornoff’s gas to a temperature change of just 2-10°C. As the Examiner finds, Fornoff teaches that limiting the humidity of the gas stream to less than 40%, the sorptive capacity of the adsorbant bed can be maintained. Final Act. 5. Also, the Examiner finds that Fornoff suggests that condensing out water is costly. Id. at 7. The Examiner concludes that it would have been obvious to determine an appropriate temperature Tc such that the reheated gas, once water has been removed, has a relative humidity of less than 75% and less than 50% “to achieve [the] desired sorptive capacity” of the bed. Final Act. 5. However, although Fornoff teaches that condensing out water is costly, the context of this teaching makes clear that Fornoff is referring to refrigeration of the gas to a temperature of 5°C. Fornoff 1:27-32. Further, although Fornoff teaches two separate cooling steps in the process example of Figure 1 for separation of condensed water from a gas stream at 50°F, Fornoff teaches that the relative humidity of the cooled gas after first cooler 12 and separator 14 is about 100% and that this cooled gas is fed to compressor 22 for increasing the gas pressure prior to being fed to second cooler 24 for cooling the compressed gas to 50-65°F for condensing more water from the gas. Id. at 2:53-3:3. The Examiner fails to adequately explain why either or both of these cooling steps is limited to cooling by only 2- Appeal 2021-001680 Application 14/909,326 9 10°C, or that cooling by only 2-10°C would have been expected to increase relative humidity of the gas after first cooler 12 and separator 14 to about 100% and would have been expected to reduce the temperature of the compressed gas to 50-65°F, such that upon heating by 30°F, the gas has a relative humidity of about 40%. See In re Stepan Co., 868 F.3d 1342, 1346 (Fed. Cir. 2017) (reversing a rejection based on a rationale of routine optimization because the rejection failed to explain why it would have been routine optimization to arrive at the claimed invention.) In addition, Fornoff teaches that the cooled and dewatered gas is then heated 30°F to ensure that the gas relative humidity is about 40% before being fed to adsorbent bed 31. Even if an ordinary artisan would have limited the amount of gas cooling to 2-10°C, the Examiner fails to adequately explain why, contrary to Fornoff’s teaching of a temperature increase of 30°F, the ordinary artisan would have limited heating to just 2- 10°C (3.6-18°F). We note that by limiting cooling and heating of the gas stream to 2-10°C, Appellant teaches that heat removed from the gas prior to water separation is returned to the gas after water separation using a heat pump system for both steps. Additionally, the Examiner fails to establish why the ordinary artisan would have desired a gas relative humidity higher than the 50% after water separation and heating that Fornoff clearly requires and the 40% Fornoff prefers. Accordingly, we do not sustain the Examiner’s obviousness rejection of claim 1, and dependent claims 2, 9-11, 13, 14, 18, and 20. Appeal 2021-001680 Application 14/909,326 10 Rejections 2-7: Obviousness over Fornoff, Flammang, Grande, and various tertiary references The Examiner rejects claims 4-9, 12, and 15-17 under 35 U.S.C. §103 as unpatentable over Fornoff in view of Flammang and Grande, and further in view of Briglia, Bresler, Dolan, Leta, Yan and Borray, or Craze. Final Act. 11-20. However, the Examiner does not rely on any of the above tertiary references to remedy the deficiencies in the combination of Fornoff, Flammang, and Grande, as discussed above. Accordingly, we likewise do not sustain the Examiner’s obviousness rejection of dependent claims 4-9, 12, and 15-17. CONCLUSION Upon consideration of the record and for the reasons set forth above and in the Appeal Brief, the Examiner’s decision to reject claims 1, 2, 4-18, and 20 under 35 U.S.C. § 103 is reversed. DECISION SUMMARY The following table summarizes the outcome of each rejection: Claim(s) Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 1, 2, 9-11, 13, 14, 18, 20 103 Fornoff, Flammang, Grande 1, 2, 9-11, 13, 14, 18, 20 4, 5, 8 103 Fornoff, Flammang, Grande 4, 5, 8 6, 7 103 Fornoff, Flammang, Grande 6, 7 9 103 Fornoff, Flammang, Grande 9 Appeal 2021-001680 Application 14/909,326 11 Claim(s) Rejected 35 U.S.C. § Reference(s)/Basis Affirmed Reversed 12 103 Fornoff, Flammang, Grande 12 15 103 Fornoff, Flammang, Grande 15 16, 17 103 Fornoff, Flammang, Grande 16, 17 Overall Outcome 1, 2, 4-18, 20 REVERSED