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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 01/21/2026 has been entered.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1, 5-8, 13-14, and 16-22 are rejected under 35 U.S.C. 103 as being unpatentable over Fuchigami et al. (US 2014/0319056A1), in view of McGinnis (US 2012/0067819A1), and Deng (US 2016/0206993).
Regarding claim 1, Fuchigami teaches a method of recovering draw agent utilized in a forward osmosis membrane cell (1) used for water purification, the method comprising the steps of:
passing diluted draw agent (refer conduit 7) to a vapor-liquid separator (11), the vapor-liquid separator being part of a draw solution fluid circuit (refer draw solution circuit including conduits 6, 7, heat exchangers 16, 17, module 11 and pump 18);
using the vapor-liquid separator to separate diluted draw agent into draw agent vapor (in conduit 10) and solvent (in conduit 12); and
condensing draw agent vapor (in heat exchanger 16 and 17), thereby recovering the draw agent as a liquid (refer [0130]); and
whereby the method does not use a compressor for compressing draw agent in a gas phase (embodiment of fig. 1 does not use compressor; fig. 1 discloses use of heat exchanger).
Fuchigami does not teach that a pressure of the draw solution fluid circuit is elevated to greater than atmospheric pressure so that the draw agent vapor is condensed to thereby recover the draw agent as a liquid.
McGinnis teaches a method recovery draw agent, the method comprising passing diluted draw agent to a vapor-liquid separator (refer fig. 5 indicating vapor-liquid separator 22), using vapor-liquid separator to separate the diluted draw agent into draw agent vapor and solvent (refer [0086] disclosing variety of vapor-liquid separators separating draw agent vapor). McGinnis discloses (in [0086]) a membrane contactor as vapor-liquid separator and discloses that pressure is used to cause liquid and gas stream to flow, as would be done in pipes with liquid or gas only.
It would have been obvious to one of ordinary skill in the art before the effective filing date of invention to modify the method of Fuchigami to use membrane contactor for separation of draw agent vapor and elevate pressure of draw solution fluid circuit because McGinnis discloses that it is advantageous to use membrane contactor because membrane contactors allows significant reduction in footprint and height requirements. It is well known in the art that membrane contactors operate at pressure higher than atmospheric pressure. This is also evidenced by Deng (refer [0063], [0065]).
Regarding claim 5, modified Fuchigami teaches limitations of claim 1 as set forth above. McGinnis further teaches using thermal energy to separate draw agent from solvent (refer [0084]). McGinnis uses membrane contactor wherein draw agent vapor is absorbed into a solvent (refer [0086]), and therefore does not require a compressor.
Regarding claim 6, modified Fuchigami teaches limitations of claim 1 as set forth above. Fuchigami teaches that the diluted draw agent is heated prior to passing to the vapor-liquid separator (Refer heat exchanger 16 prior to vapor liquid separator 11).
Regarding claim 7, modified Fuchigami teaches limitations of claim 6 as set forth above. Fuchigami teaches that heat from solvent separated in the vapor-liquid separator is used to heat the diluted draw agent prior to passing to the vapor-liquid separator (refer heat exchanger 16 using heated fluid from conduit 10 exchanging heat with diluted draw solution in conduit 7).
Regarding claim 8, modified Fuchigami teaches limitations of claim 7 as set forth above. In embodiment of fig. 3, Fuchigami teaches that the heated diluted draw solution is further heated by an additional heater using an external heat source (refer fig. 3 disclosing use of sunlight to supply heat to reboiler 15).
Regarding claim 13, modified Fuchigami teaches limitations of claim 1 as set forth above. Fuchigami teaches that the draw agent comprises ammonia (Refer [0081]).
Regarding claim 14, modified Fuchigami teaches limitations of claim 1 as set forth above. Fuchigami teaches that the solvent is water (refer abstract).
Regarding claim 16, modified Fuchigami teaches limitations of claim 1 as set forth above. Deng discloses that pressure of at least 20 bar may be used (Refer [0063]).
Regarding claim 17, modified Fuchigami teaches limitations of claim 1 as set forth above. It would have been an obvious matter of choice to one of ordinary skill in the art to use the membrane contactor in horizontal position or vertical position. Using the membrane contactor in horizontal position results in vapor being collected and condensed in upper portion of the contactor.
Regarding claims 18-19, modified Fuchigami teaches limitations of claim 1 as set forth above. McGinnis (refer [0086]) and Deng (refer [0063])discloses that the solvent is pressurized, wherein the condensed draw agent vapor which has been recovered as a liquid is mixed with the pressurised solvent.
Regarding claim 20, modified Fuchigami teaches limitations of claim 18 as set forth above. McGinnis (refer [0086]) and Deng (refer [0063])discloses that the solvent is pressurized. Selecting the pressure of the solvent would have been an obvious matter of choice to one of ordinary skill in the art. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955).
Regarding claim 21, modified Fuchigami teaches limitations of claim 1 as set forth above. McGinnis (refer [0086]) discloses pressurizing the solvent in which draw agent is condensed. McGinnis also teaches supplying the solvent with the draw agent back to forward osmosis module (Refer fig. 5). Selecting to maintain a pressure in the draw solution return would have been obvious to one of ordinary skill in the art to convey the draw solution in the draw solution fluid circuit.
Regarding claim 22, modified Fuchigami teaches limitations of claim 18 as set forth above. Fuchigami discloses condensing draw agent vapor (in heat exchanger 16 and 17). McGinnis also discloses that additionally or alternatively, a condenser may then be used to condense all or a portion of the vapors (Refer [0091]).
Response to Arguments
Applicant’s arguments with respect to claim(s) 1 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument. The limitation “a pressure of the draw solution fluid circuit is elevated to greater than atmospheric pressure so that the draw agent vapor is condensed to thereby recover the draw agent as a liquid” is taught by McGinnis (Refer claim rejection above).
Conclusion
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/PRANAV N PATEL/Primary Examiner, Art Unit 1777