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 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.
Claims 1-2 and 4-9 are rejected under 35 U.S.C. 103 as being unpatentable over Li et al (US 2013/0025458 A1).
With regards to claim 1, Li discloses a composite hollow ceramic fiber comprising a porous hollow core (i.e., a hollow fiber membrane comprising an inner porous layer) surrounded by a thin, dense, relatively non-porous sheath which is typically void-free (i.e., an outer separation layer surrounding the inner porous layer), wherein a bore extends axially through the hollow core (i.e., includes an inner bore, wherein the inner porous layer surrounds the inner bore), and further, wherein the porous hollow core (i.e., inner porous layer) has an interconnecting network of pores (Li: abstract; para. [0020]-[0021], [0088]-[0090], and [0098]). The composite hollow ceramic fiber of Li is considered “asymmetric” in that it has layers of asymmetric porosity (i.e., a porous hollow core and a relatively non-porous sheath), and further, the sheath of Li is void-free, which is within the scope of the phrase “substantially non-porous” (Li: para. [0090]). However, in the interest of compact prosecution, it is noted that “substantially” is a broad term, per MPEP 2173.05(b), and Figures 1(b) and 1(c) of Applicant’s drawings depict outer separation layers which comprise a small number of pores, and therefore, the phrase “substantially non-porous” does not preclude the existence of pores (Li: para. [0090]). It is additionally noted that, technically, any bore must have a diameter, and therefore, the bore (i.e., inner bore) of Li is considered to have an inner diameter (Li: para. [0088]). Regarding the present claim language directed to oxidative coupling of methane, the ceramic material forming both the porous hollow core and thin, dense sheath of Li is capable of facilitating an oxidative reaction such as partial oxidation of methane (i.e., the inner porous layer of Li comprises an oxidative coupling of methane (OCM) catalyst), though in the interest of compact prosecution, it is noted that the ceramic material of Li may include a barium doped gadolinium (BCG) such as BaCe0.8Gd0.2O3-δ, which is admitted by the present specification to be constitute an OCM catalyst according to the present claims (Li: para. [0130] and [0174]; Present Specification PGPub: para. [0033]). In addition, the composite hollow ceramic fiber of Li is considered to meet the intended use of “for oxidative coupling of methane” in that it includes ceramic material capable of oxidizing methane, though in the interest of compact prosecution, the phrase “for oxidative coupling of methane” is broader in scope (Li: para. [0130] and [0174]; Present Specification PGPub: para. [0033]).
With regards to the recitation that the claimed outer separation layer is “for oxygen separation and transport through the outer separation layer,” Li further discloses its thin, dense sheath is gas-tight yet allows from the flow of oxygen at a high level of flux (i.e., as best understood, the outer separation layer of Li separates and transports oxygen through itself) (Li: para. [0092] and [0098]). In the interest of compact prosecution, the phrase “for oxygen separation and transport through the outer separation layer” is considered to recite an intended use. Li discloses its porous hollow core (i.e., inner porous layer) as having a thickness, and since the inner bore extends axially through the porous hollow core and the thin, dense sheath (i.e., outer separating layer) surrounds the porous hollow core Li, then as best understood, the thickness of the porous hollow core of Li extends from an outer circumferential edge of thinner bore to an interface between the inner porous layer and the outer separating layer (Li: para. [0088] and [0094]). In addition, Li further discloses its thin, dense sheath as having a particular thickness, and since the thin, dense sheath surrounds the hollow porous core, then as best understood, the thin, dense sheath thickness is measured from an interface to an outer circumferential edge of the hollow fiber membrane (i.e., the sheath is defined as beginning at the location of the porous hollow core, or in other words, an interface of the porous hollow core, to an opposing surface at which the sheath terminates, which may be considered an outer circumferential edge of the hollow fiber membrane) (Li: para. [0088] and [0094]).
With regards to the recitation that “the thickness of the inner porous layer is greater than the thickness of the outer separation layer,” Li discloses a core thickness (i.e., inner porous layer thickness) of 35 to 1400 microns and a sheath thickness (i.e., outer separation layer thickness) of 2 to 50 microns (Li: para. [0094]). As best understood, therefore, Li contemplates that the thickness of its core may be greater than, less than, or equal to a thickness of its sheath (Li: para. [0094]). Li teaches that a “relatively small sheath thickness can yield impressive improvements in flux” and that “[b]ecause the flux of oxygen or hydrogen across the membrane is highly dependent upon the thickness of the sheath, a relatively thin sheath is formed on the core” (Li: para. [0093] and [0095]). Li further describes its sheath is being formed from a “thin” annulus, and its core as formed from a “thick” annulus (Li: para. [0119]). Selection of a core (i.e., inner porous layer) having a thickness which is greater than that of a sheath (i.e., inner porous layer) would have been obvious to try, as Li provides a set of ranges including a set of finite of identified, predictable solutions (i.e., the workable ranges of Li contemplate three separate thickness combinations: an core with a greater thickness than a sheath thickness, a core with a smaller thickness than a sheath thickness, or a core with a thickness equal to a sheath thickness) (see above discussion). Alternatively, a person of ordinary skill would have been guided towards the selection of a core thickness which is greater than that of a sheath thickness as Li teaches smaller sheath thicknesses as achieving increased oxygen flux, and since Li is replete with language describing a sheath as “thin” compared to its core (i.e., Li constantly refers to its sheath as “thin,” and the process producing the fiber of Li forms its sheath using a “thin” annulus and its core using a “thick” annulus) (see above discussion). Regarding the claim language directed to thicknesses an and inner porous layer porosity selected “such that a rate of transport of oxygen through the outer separation layer substantially equals a rate of methane activation at the inner porous layer, it is noted that such language is rather broad in that it provides no information regarding the conditions of transport. The claim does not specify certain variables upon which the claimed rates depend (i.e., concentrations of methane and oxygen flowing to and from the composite fiber, flow rates of methane and oxygen flowing into and out of the composite fiber, temperature, pressure, and other parameters affecting methane catalytic rate are not specified). In the interest of compact prosecution, it is noted that “substantially” is a broad term, per MPEP 2173.05(b). In addition, the submitted amendment “when a methane containing source… of about 700⁰C to 900⁰C” does not remedy the aforementioned deficiencies. The claim still does not recite, for example, flow rates of methane and oxygen, and thus, flow rates of methane and oxygen could be adjusted to meet the claimed function (i.e., the claimed function still depends on unclaimed variables, which themselves could be used to meet the claimed function).
With regards to claim 2, the hollow core (i.e., inner porous layer) of Li comprises barium doped gadolinium (BCG) (see above discussion).
With regards to claim 4, the hollow core (i.e., inner porous layer) of Li comprises barium doped gadolinium (BCG) (see above discussion).
With regards to claim 5, Li discloses a composite hollow ceramic fiber comprising a porous hollow core (i.e., a hollow fiber membrane comprising an inner porous layer) surrounded by a thin, dense, relatively non-porous sheath which is typically void-free (i.e., an outer separation layer surrounding the inner porous layer), wherein a bore extends axially through the hollow core (i.e., includes an inner bore, wherein the inner porous layer surrounds the inner bore), and further, wherein the porous hollow core (i.e., inner porous layer) has an interconnecting network of pores (Li: para. [0089]). (Li: abstract; para. [0020]-[0021], [0088]-[0090], and [0098]). The composite hollow ceramic fiber of Li is considered “asymmetric” in that it has layers of asymmetric porosity (i.e., a porous hollow core and a relatively non-porous sheath), and further, the sheath of Li is void-free, which is within the scope of the phrase “substantially non-porous” (Li: para. [0090]). However, in the interest of compact prosecution, it is noted that “substantially” is a broad term, per MPEP 2173.05(b), and Figures 1(b) and 1(c) of Applicant’s drawings depict outer separation layers which comprise a small number of pores, and therefore, the phrase “substantially non-porous” does not preclude the existence of pores (Li: para. [0090]). It is additionally noted that, technically, any bore must have a diameter, and therefore, the bore (i.e., inner bore) of Li is considered to have an inner diameter (Li: para. [0088]). Regarding the present claim language directed to oxidative coupling of methane and the inclusion of barium cerate doped with gadolinium in both the inner porous layer and outer separation layer, the ceramic material of Li may include BaCe0.8Gd0.2O3-δ (i.e., a barium cerate doped with gadolinium which is admitted by the present specification to provide oxidative coupling of methane) (Li: para. [0130] and [0174]; Present Specification PGPub: para. [0033]). In addition, the composite hollow ceramic fiber of Li is considered to meet the intended use of “for oxidative coupling of methane” in that it includes ceramic material capable of oxidizing methane, though in the interest of compact prosecution, the phrase “for oxidative coupling of methane” is broader in scope (Li: para. [0130] and [0174]; Present Specification PGPub: para. [0033]). Furthermore, Li discloses its porous hollow core (i.e., inner porous layer) as having a thickness, and since the inner bore extends axially through the porous hollow core and the thin, dense sheath (i.e., outer separating layer) surrounds the porous hollow core Li, then as best understood, the thickness of the porous hollow core of Li extends from an outer circumferential edge of thinner bore to an interface between the inner porous layer and the outer separating layer (Li: para. [0088] and [0094]). Li further discloses its thin, dense sheath as having a particular thickness, and since the thin, dense sheath surrounds the hollow porous core, then as best understood, the thin, dense sheath thickness is measured from an interface to an outer circumferential edge of the hollow fiber membrane (i.e., the sheath is defined as beginning at the location of the porous hollow core, or in other words, an interface of the porous hollow core, to an opposing surface at which the sheath terminates, which may be considered an outer circumferential edge of the hollow fiber membrane) (Li: para. [0088] and [0094]). With regards to the recitation that “the thickness of the inner porous layer is greater than the thickness of the outer separation layer,” Li discloses a core thickness (i.e., inner porous layer thickness) of 35 to 1400 microns and a sheath thickness (i.e., outer separation layer thickness) of 2 to 50 microns (Li: para. [0094]). As best understood, therefore, Li contemplates that the thickness of its core may be greater than, less than, or equal to a thickness of its sheath (Li: para. [0094]). Li teaches that a “relatively small sheath thickness can yield impressive improvements in flux” and that “[b]ecause the flux of oxygen or hydrogen across the membrane is highly dependent upon the thickness of the sheath, a relatively thin sheath is formed on the core” (Li: para. [0093] and [0095]). Li further describes its sheath is being formed from a “thin” annulus, and its core as formed from a “thick” annulus (Li: para. [0119]). Selection of a core (i.e., inner porous layer) having a thickness which is greater than that of a sheath (i.e., inner porous layer) would have been obvious to try, as Li provides a set of ranges including a set of finite of identified, predictable solutions (i.e., the workable ranges of Li contemplate three separate thickness combinations: an core with a greater thickness than a sheath thickness, a core with a smaller thickness than a sheath thickness, or a core with a thickness equal to a sheath thickness) (see above discussion). Alternatively, a person of ordinary skill would have been guided towards the selection of a core thickness which is greater than that of a sheath thickness as Li teaches smaller sheath thicknesses as achieving increased oxygen flux, and since Li is replete with language describing a sheath as “thin” compared to its core (i.e., Li constantly refers to its sheath as “thin,” and the process producing the fiber of Li forms its sheath using a “thin” annulus and its core using a “thick” annulus) (see above discussion).
With regards to claim 6, the barium cerate doped with gadolinium is BaCe0.8Gd0.2O3-δ (see above discussion).
With regards to claim 7, the composite hollow fiber of Li has an outer diameter of 105 to 4200 microns (i.e., 0.105 to 4.2 mm) and an inner diameter of 35 to 1400 microns (i.e., 0.035 to 1.4 mm) (Li: para. [0094]). These ranges overlap the claimed outer diameter and inner diameter ranges of about 0.5 mm to about 3 mm and about 0.3 mm to about 2.5 mm, respectively, thereby establishing a prima facie case of obviousness (Li: para. [0094]). See MPEP 2144.05.
With regards to claim 8, the composite hollow fiber of Li has a core thickness (i.e., inner porous layer thickness) of 35 to 1400 microns and a sheath thickness (i.e., outer separation layer thickness of 2 to 50 microns (Li: para. [0094]). These ranges overlap the claimed inner porous layer and outer separation layer thickness ranges of about 250 microns to about 1300 microns and about 5 microns to about 100 microns, respectively, thereby establishing a prima facie case of obviousness (Li: para. [0094]). See MPEP 2144.05.
With regards to claim 9, it is noted that the present specification defines “visible cracks or defects” as referring to those cracks or defects visible through imaging such as scanning electron microscopy imaging (Present Specification PGPub: para. [0038]). It is noted that “substantially” is a broad term, per MPEP 2173.05(b), and Figures 1(b), 1(c), and 5(b) of Applicant’s drawings depict SEM and optical images which include interfaces having pores, non-uniformities, and other defects. Li teaches that its composite fibers should be formed to have “fewer physical defects” in order to provide improved selectivity for oxygen (Li: para. [0005] and [0189]). It would have been obvious to a person of ordinary skill to have formed the hollow fiber of Li to have few physical defects (which would include its interface, in addition to its layers) in order to improve its selectivity for oxygen, and as best understood, the existence of few defects remains within the scope of the present claim language (Present Specification PGPub: para. [0038; Li: para. [0005] and [0189]).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Li et al as applied to claim 1 above, and in further view of Kawi et al (US 2015/0298102 A1).
With regards to claim 3, Li teaches an asymmetric hollow fiber membrane as applied to claim 1 above (see above discussion). Li does not appear to further disclose or teach the inclusion of an inert layer arranged between its inner porous layer and outer separation layer.
Kawi is directed to a catalytic hollow fiber comprising a selection layer 3, a catalyst layer 1, and a porous support layer 2 located therebetween (Kawi: para. [0005], [0021], [0023], and [0025] Fig. 1). Kawi more specifically discloses its porous support layer 2 as made of a combination of alumina and yttrium-stabilized zirconia, which, as best understood, are inert materials according to the present specification (Kawi: para. [0026]; Present Specification PGPub: para. [0034]). However, in the interest of compact prosecution, the present specification does not provide a particular definition for the phrase “inert layer,” and the present specification further states that the inert layer “can be used to prevent thermal solid state reactions between the OCM catalyst and O2- conducting membrane,” which is technically a function met by any impeding layer of material (i.e., any layer located between the inner porous layer, which appears to be the OCM catalyst layer of the present specification, and the outer separation layer, which appears to be the O2- conducting membrane, will necessarily impede flow therebetween) (Present Specification PGPub: para. [0034]). Kawi teaches that its support layer provides high mechanical strength, thermal stability, and chemical resistance to its hollow fiber, and in particular, that specifically placing support layer between the catalyst layer and selection layer provides improved resistance to mechanical damage (Kawi: para. [0022] and [0025]). Li and Kawi are considered analogous art in that they are related to the same field of endeavor of hollow fiber ceramic membranes for the catalytic oxidation of methane (Li: para. [0011]-[0012]; Kawi: para. [0026]-[0027]). A person of ordinary skill in the art would have found it obvious to have further included the inert porous support layer 2 of Kawi between the inner porous layer and outer separation layer in the hollow fiber of Li in order to provide improved mechanical strength, thermal stability, chemical resistance, and resistance to mechanical damage (Kawi: para. [0022] and [0025]).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Li et al as applied to claim 1 above, and in further view of Kelly et al (US 2015/0096506 A1).
With regards to claim 10, Li teaches an asymmetric hollow fiber membrane as applied to claim 1 above (see above discussion). Li does not appear to explicitly disclose its inner porous layer as having a porosity of up to about 30%. However, Li teaches that the porosity of its core (i.e., inner porous layer) should allow for “relatively high flux” and that it is known to adjust porosity in asymmetric monolithic fibers (i.e., it is well-known in the art to select a particular porosity) (Li: para. [0017] and [0089]).
Kelly is directed to ceramic oxygen transport membrane tubes for partial oxidation and reforming of natural gas comprising a porous surface exchange layer located adjacent an intermediate porous layer and a dense layer, wherein the porous surface exchange layer has a porosity of from about 30 percent to about 60 percent (Kelly: para. [0003], [0051], and [0062]-[0063]; claims 1-2 and 12-13). As best understood, the pores of the porous surface exchange layer result in the formation of a permeate side (i.e., the porous surface exchange layer is permeable), and further, the porous surface exchange layer exhibits an increased permeability relative to the adjacent intermediate porous layer, thereby allowing for a high rate of oxygen transport (Kelly: para. [0062]-[0063] and [0067]). Li and Kelly are analogous art in that they are related to the same field of endeavor of tubular oxygen transport membranes for the oxidation of methane (i.e., natural gas) (Li: para. [0091] and [0130]; Kelly: para. [0003] and [0051]). A person of ordinary skill in the art would have found it obvious to have selected from the porosity range of Kelly for the inner porous layer of Li in order to ensure that the inner porous layer of Li provides a sufficient rate of oxygen transport, as desired by Li (Li: para. [0017] and [0089]; Kelly: para. [0062]-[0063] and [0067]). The range taught by Kelly (i.e., about 30 percent to about 60 percent) overlaps the claimed range (i.e., up to about 30%), thereby establishing a prima facie case of obviousness (Kelly: para. [0003], [0051], and [0062]-[0063]). See MPEP 2144.05.
Response to Arguments
Applicant’s arguments with respect to the claim objection and the rejection under 35 U.S.C. 112(b) have been fully considered and they are found persuasive. Applicant has clarified the acronym of claim 1, changed “the outer separating layer” to “the outer separation layer,” and changed “a relative thicknesses” to “relative thicknesses.” Therefore, the claim objection and the rejection under 35 U.S.C. 112(b) have been withdrawn.
The remainder of Applicant’s arguments have been fully considered but they are not found persuasive.
Applicant argues that Li does not teach thickness selection based on matching flux of methane and oxygen in the presence of methane and oxygen (that is when a methane containing source and oxygen is/are flowed through the membrane as now claimed). Applicant argues that the claim amendment eliminates the hypothetical of when methane and oxygen flow are zero. Applicant further argues that the inventors have advantageously found that improved performance was achieved when the thicknesses of the claimed invention were tailored to match the flux, which is considered an unexpected discovery by Applicant. Applicant additionally argues that Kawi does not cure the deficiencies, of Li, as Kawi was not relied upon to teach the claimed flux property. None of these arguments are found persuasive as they are not commensurate in scope with the claims. Although it is agreed that the claim amendment eliminates the hypothetical of when methane and oxygen flow are zero, the claims as amended still do not provide enough process particulars which necessarily imply a structural difference. Whether or not the claimed limitation is met still depends on the flow rates of methane and oxygen, which are not specified by the claim. For a given membrane, the flow rates of methane and oxygen can be adjusted until the rate of methane activation equals the rate of transport of oxygen through the outer separation layer. Applicant’s property still does not wholly depend on the specific structural features of the claimed invention. In addition, the phrase “substantially equals a rate of methane activation” was noted as rather broad in the previous grounds of rejection. The position that the rate of methane activation need not precisely equal the flux of oxygen, due to the term “substantially”, is maintained. With particular regards to the arguments of unexpected results, Applicant has not provided any particular evidence of unexpected results which compares the claimed invention to the membrane of Li, and therefore, Applicant’s arguments are not persuasive.
Conclusion
THIS ACTION IS MADE FINAL. 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.
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/E.W./
Examiner, Art Unit 1783
/MARIA V EWALD/Supervisory Patent Examiner, Art Unit 1783