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 .
Election/Restrictions
Applicant’s election without traverse of Invention I, claims 1-6 in the reply filed on 03/16/2026 is acknowledged.
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 non-obviousness.
Claims 1-4, 6 are rejected under 35 U.S.C. 103 as being unpatentable over Leigh et al. U.S. Pub. No. 20040025507 A1, February 12, 2004 (hereinafter “Leigh”) in view of Bronicki et al. U.S. Pub. No. 6332321 B1, December 25, 2001 (hereinafter “Bronicki”).
Regarding claim 1, Leigh discloses a method for generating a nitrogen-enriched stream from ambient air, including compressing a supply stream of ambient air (fig. 1, air source 100; paragraph 0022) to produce a pressurized air stream via compressor (10) and supplying the pressurized air to a membrane module assembly (16) that separates the air into a nitrogen-enriched stream (20) and an oxygen-enriched stream (18) (paragraphs 0024; figs 1-3). Leigh further discloses that the nitrogen-enriched stream (20) is directed to a turbine (22), which expands the stream and recovers energy, and that the recovered energy is transmitted through the shaft (26) to drive the compressor supplying the pressurized air (paragraphs 0029-0032; figs. 1-3). However, Leigh fails to disclose that use of multiple compression stages as recited.
Bronicki disclose compressing air using staged compression, including a pre-compressor (110) and a main compressor (130), to produce pressurized air for use in gas turbine system (col. 4, lines 1-11; figs 1-2). Bronicki discloses that such staged compression improves system efficiency and performance by reducing the work required for compression and conditioning the air prior to further processing (col. 13, lines 36-40). Bronicki further discloses a precompression device that increases the pressure of ambient air prior to supplying that air to a main compressor (col.4, lines 30-55). The pressurized air from the pre-compressor is then supplied to the main compressor, which further compresses the air. Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the system of Leigh to include multiple compression stages as taught by Bronicki in order to improve compression efficiency and overall system performance.
Regarding claim 2, Leigh discloses a turbine that receives the nitrogen-enriched stream and recovers energy, wherein the recovered energy is transmitted through a shaft (26) to drive the compressor (figs 1-3; paragraph 0030-0031). The energy recovered from expansion of the nitrogen-enriched gas is transferred through a shaft to the compressor supplying compressed air to the membrane module. Additionally, Bronicki disclose systems in which turbines are mechanically coupled via shafts (16, 35, 160) to compression devices, such as pre-compressors, to provide power for compression (fig. 3; col. 5, lines 5-29). This reinforces the use of mechanical coupling between expansion devices and compressors in gas processing systems. It would have been obvious to one of ordinary skill in the art at the time of the invention to implement the compressor and expander of Leigh as mechanically via shaft, in order to efficiently transfer energy recovered from expansion to the compression stage and reduce external power requirements.
Regarding claim 3, Leigh discloses that the nitrogen-enriched stream, after expansion in a turbine, is cooled and supplied for use (0019). A heat exchanger is positioned within the systems for conditioning air streams, including between the compressor and the membrane module (fig.1-3; paragraphs 0022-0023). Bronicki discloses cooling compressed or pre-compressed air using heat exchange devices (col. 7, lines 37-47), including direct contact heat exchangers and coolers positioned between compression stages (figs 2-3; col. 8, lines 10-20). It would have been obvious to one of ordinary skill in the art at the time of the invention to utilize the expanded and cooled nitrogen-enriched stream of Leigh, as a cooling medium in a heat exchange relationship with the supply stream, in order to improve energy efficiency in gas processing systems.
Regarding claim 4, Leigh discloses filtering compressed gas prior to further processing, including a filter (14) positioned downstream of a compressor and upstream of subsequent system components (figs. 1-3; paragraph 0023). This filter removes particulates and contaminants from the compressed air stream prior to further processing, including separation. Bronicki also discloses the use of filters (fig. 1, filter 113) positioned upstream of compressors to remove entrained particles and protect downstream equipment (col. 4, lines 5-38). It would have been obvious to one of ordinary skill in the art at the time of invention to include a filter prior to further compression of the combined device, in order to remove contaminants and protect downstream compressor components, as such filtration is well-known in compressed gas systems.
Regarding claim 6, Leigh discloses that the membrane module assembly produces a nitrogen-enriched air stream (20) that is supplied for use, such as providing nitrogen-enriched gas to fuel tank ullage (figs. 1-3; paragraphs 0020, 0024). It would have been obvious to one of ordinary skill in the art to withdraw the nitrogen-enriched stream and utilize it as product stream, in view of Bronicki.
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Leigh et al. U.S. Pub. No. 20040025507 A1, February 12, 2004 (hereinafter “Leigh”) in view of Bronicki et al. U.S. Pub. No. 6332321 B1, December 25, 2001 (hereinafter “Bronicki”), in further view of Moll et al. U.S. Pub. No. 5352272 A, October 04, 1994 (hereinafter “Moll”).
Leigh in view of Bronicki is relied upon as above.
Regarding claim 5, Leigh fails to disclose that a control valve located downstream of the membrane stage is used to control the flow of the nitrogen-enriched non-permeate stream to the volumetric expander. Bronicki discloses valves for controlling airflow within conduits and selectively directing flow between system (figs 6-7; col 9, lines 36-66). However, Moll discloses that fine control of the process may be obtained by passing a portion of a process stream through a control valve, bypassing either the turboexpander or a heat exchanger (col. 30, lines 26-30; col. 32, lines 38-57). It would have been obvious to one of ordinary skill in the art at the time of the invention to incorporate a control valve downstream of the membrane stage of the combined system, to regulate the flow of the nitrogen-enriched stream to the expander, as the placement of valves along process streams is used for flow control.
Prior Art of Record
The prior art made of record and not relied upon is considered pertinent to applicant’s disclosure.
Haugland et al. (U. S. Pub. NO. 20220401878 A1, December 22, 2022) teaches reducing energy consumption for marine and offshore membrane applications.
Conclusion
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/CHRISTOPHER P JONES/Primary Examiner, Art Unit 1776
/M.N.E./Examiner, Art Unit 1776
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