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 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.
Claims 1-4, 6, 15, 19, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Xie et al. (US 5,817,902, “Xie”) in view of Eugene (EP 0 254 277 B1, “Eugene”).
Regarding claim 1, Xie teaches a process for oligomerization of ethylene to produce α-olefins using a vertically elongated jet-loop reactor operated at about 100–140°C and 2–10 MPa, comprising a liquid phase and a gas phase, a liquid injection device/nozzle, a gas injection device, and a central guide pipe positioned along the vertical axis of the reactor. The liquid jet entrains ethylene gas and forms a gas/liquid mixture flowing downward through the central guide pipe, after which the mixture flows upward through the annular region between the guide pipe and reactor wall, thereby establishing internal loop circulation. Unreacted ethylene entering the gas space above the liquid level is recirculated to the reaction stream (Xie, Fig. 1; col. 4, line 6–col. 5, line 53). Xie further teaches ethylene oligomerization/chain growth for production of α-olefins, including C4, C6 and C8 α-olefins (Xie, col. 1, line 63 through col. 2, line 43).
Xie thus teaches a reactor containing both a gas phase and a liquid phase and the claimed downward central and upward outer circulation. Xie does not expressly disclose a catalytic system comprising a metal precursor based on nickel, titanium, or chromium.
Eugene teaches oligomerization of ethylene to α-olefins in a liquid phase using a catalytic system comprising a transition-metal compound selected from, inter alia, nickel and chromium compounds (Eugene, p. 2, lines 26-50; claim 1; see also p. 3). It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to employ the known nickel- or chromium-based ethylene-oligomerization catalyst of Eugene in the ethylene-oligomerization reactor of Xie because Eugene teaches such catalysts as suitable catalysts for converting ethylene into α-olefins, thereby providing a known alternative catalytic system for carrying out the same type of oligomerization reaction.
Xie and Eugene do not expressly disclose that the degree of saturation of dissolved gaseous ethylene in the liquid phase is greater than 70.0%. However, the modified process of Xie is substantially the same gas/liquid ethylene-oligomerization process operated under substantially the same reaction conditions as presently claimed, including contacting gaseous ethylene with a liquid reaction phase under elevated pressure and temperature with vigorous gas/liquid circulation and contacting. Xie specifically employs high-pressure ethylene, liquid-jet entrainment of ethylene, repeated gas/liquid circulation and recycling of unreacted ethylene. It would have been within the level of ordinary skill in the art to operate the modified process of Xie at a dissolved-ethylene saturation greater than 70.0%, since the amount of ethylene dissolved in the liquid reaction phase is an operating condition affecting availability of ethylene to the liquid-phase oligomerization reaction, and increasing dissolution predictably increases contact of ethylene with the catalytic system and conversion. The claimed lower limit of greater than 70.0% represents optimization of the operating conditions of the otherwise substantially identical process, particularly absent evidence that 70.0% constitutes a critical threshold or produces an unexpected result.
Regarding claims 2 and 3, Xie further teaches introducing the gas and liquid in the upper region of the central circulation pipe so that the liquid jet entrains the gaseous ethylene downward through the central region and thereafter upward through the outer annular circulation region, with the liquid-injection arrangement positioned relative to the gas introduction arrangement as shown in Fig. 1 (Xie, Fig. 1; col. 4, line 54–col. 5, line 27).
Regarding claim 4, Xie's central guide pipe has a substantially solid wall over its height and therefore satisfies the first alternative of claim 4 (Xie, Fig. 1; col. 4, line 54–col. 5, line 31).
Regarding claim 6, Xie teaches block-off plate 37 positioned opposite/below the lower outlet of the central guide pipe, thereby providing a deflector facing the lower aperture of the central pipe (Xie, Fig. 1; col. 5, lines 28–31).
Regarding claims 15, 19, and 20, Xie's gaseous feedstock is ethylene. Ethylene is a C2 olefin and is expressly one of the feedstocks recited in claims 15, 19, and 20 (Xie, col. 2–5).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Xie in view of Eugene as applied to claim 1 above, and further in view of Ore (US 4,196,172).
Xie and Eugene do not expressly teach that the lower end of the central pipe is flared or tapered.
Ore teaches a vertically disposed draft tube having an outwardly flared lower skirt portion 66 at its lower end (Ore, Fig. IV; col. 10, lines 13-31).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to provide the lower end of Xie's central guide pipe with the known flared configuration of Ore to provide a smoother transition of the circulating gas/liquid stream between the central descending region and the surrounding ascending region and thereby facilitate circulation.
Claims 7, 8, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Xie in view of Eugene as applied above, and further in view of Hochman (US 3,737,288).
Xie teaches a deflector/block-off plate but does not expressly teach the particular spacing and dimensional relationships recited in claims 7, 8, and 16.
Hochman teaches the known placement of a flow deflector adjacent an end of a draft tube and teaches selection of dimensional relationships between the draft tube and deflector for controlling circulating flow (Hochman, Fig. 1; col. 2, lines 44-65; col. 3, lines 15-18).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to dimension and position the deflector of Xie relative to the central pipe in accordance with the known draft-tube/deflector arrangement of Hochman to efficiently redirect the circulating gas/liquid stream and avoid undesirable flow restriction. Selection of an effective deflector diameter and spacing within the claimed ranges would have involved routine optimization of known dimensional parameters of the circulation system.
Claims 9 and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Xie in view of Eugene as applied above, and further in view of Augier et al. (US 10,857,514 B2, “Augier”).
Xie and Eugene do not expressly teach the recirculation loop including the external heat exchanger and cooled-liquid return arrangement recited in claims 9 and 10.
Regarding claim 9, Augier teaches an olefin-oligomerization gas/liquid reactor comprising a liquid recirculation loop having withdrawal means for withdrawing liquid from the reactor, a heat exchanger for cooling the withdrawn liquid fraction, and means for reintroducing the cooled liquid into the upper part of the gas/liquid reactor (Augier, Fig. 1; col. 2, approximately lines 25–35; see also claims 1–2). Augier explains that the recirculation loop provides good heat transfer, concentration homogeneity and temperature control in the reaction volume.
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to provide the modified Xie reactor with Augier's external cooling recirculation loop to remove heat generated by the exothermic oligomerization reaction and maintain a desired and more homogeneous reaction temperature.
Regarding claim 10, it would further have been obvious to introduce the cooled recycle liquid through Xie's existing upper liquid-injection arrangement because doing so utilizes the existing liquid inlet to provide both cooled-liquid return and the liquid circulation/entrainment function, thereby avoiding an unnecessary separate inlet.
Claims 11, 12, 17, and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Xie in view of Eugene as applied to claim 1 above, and further in view of Zheng et al. (US 2018/0119083 A1, “Zheng”).
Xie and Eugene do not expressly disclose the numerical central-pipe/reactor diameter and height ratios recited in claims 11, 12, 17, and 18.
Zheng teaches a gas/liquid draft-tube circulation reactor and discloses relative dimensions of the draft tube and reactor from which the claimed central-pipe/reactor diameter and height relationships are taught or fall within the claimed ranges (Zheng, Fig. 1; ¶¶[0045]–[0047]; Example 1).
Regarding claims 11, 12, 17, and 18, it would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to employ the relative draft-tube dimensions taught by Zheng in Xie's internal-circulation reactor because the relative dimensions of the draft tube and reactor determine the respective cross-sectional areas and flow paths of the central and annular circulation regions. Selection of dimensions within the disclosed overlapping ranges would have been a routine design optimization for obtaining effective internal gas/liquid circulation.
Claims 13 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Xie in view of Eugene as applied above, and further in view of Koppehele et al. (US 4,361,285).
Xie and Eugene do not expressly teach the claimed relative arrangement of the gas and liquid injection orifices such that liquid injection can reduce gas-bubble size by shear.
Koppehele teaches a gas/liquid injection apparatus comprising adjacent gas and liquid injection passages and orifices arranged such that the respective fluid streams interact under shear to provide mixing, breakup and dispersion (Koppehele, Figs. 1–2; col. 3, line 49 through col. 5, line 68; claims 1 and 3).
Regarding claim 13, although Koppehele principally describes operation in which gas acts upon and atomizes a liquid stream, the disclosed injector is a gas/liquid shear and mixing apparatus and its structure is not limited to a particular fluid being the continuous or dispersed phase. It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to employ Koppehele's gas/liquid injection arrangement in the modified Xie reactor to improve gas/liquid contacting and dispersion. When employed within the liquid phase of Xie's reactor with liquid and gaseous ethylene supplied through the respective passages, interaction of the liquid and gas streams would predictably shear the gaseous ethylene into smaller bubbles, thereby improving gas/liquid contacting.
Regarding claim 14, Koppehele further teaches the gas and liquid discharge passages/orifices extended through respective injection passages/tubes (Koppehele, Figs. 1–3; col. 3, line 49–col. 4, line 25).
Claims 21–23 are rejected under 35 U.S.C. 103 as being unpatentable over Xie in view of Eugene as applied above, and further in view of JP 2009-088078 A.
Xie and Eugene do not expressly teach the particular circular-ring/coaxial gas and liquid injection-device configurations recited in claims 21–23.
JP ’078 teaches gas and liquid discharge paths arranged so that the gas and liquid streams intersect/collide (Figs. 8A–8C, 9; claims 1, 3–5; corresponding description of elements 326–329). Although JP ’078 does not expressly disclose that the respective trajectories are perpendicular, it would have been obvious to one having ordinary skill in the art to select the angle of intersection, including a perpendicular intersection, to provide effective impingement, shear and gas/liquid dispersion, since the angle at which the known interacting streams meet is a result-effective geometric parameter.
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to employ the concentric annular gas/liquid injection arrangement of JP 2009-088078 in the modified Xie reactor because such an arrangement provides circumferentially distributed and substantially uniform interaction between the gas and liquid streams and thereby improves gas/liquid contacting and dispersion.
Accordingly, the concentric annular injector arrangement teaches or suggests the circular-ring gas and/or liquid devices of claim 21 and the coaxial circular-ring arrangement of claim 22.
Regarding claim 23, arranging the interacting gas and liquid streams to meet substantially perpendicularly would have been an obvious geometric implementation of the disclosed intersecting streams to provide effective shear and dispersion.
Claim 24 is rejected under 35 U.S.C. 103 as being unpatentable over Xie in view of Eugene as applied to claim 1 above, and further in view of Brown et al. (US 2005/0049447 A1, “Brown”).
Xie and Eugene do not expressly disclose the particular nickel precursor recited in claim 24.
Brown teaches ethylene oligomerization using a catalyst comprising a simple divalent nickel salt and teaches suitable nickel compounds for carrying out ethylene oligomerization (Brown, ¶¶[0005], [0007], [0009]–[0010], [0028]).
It would have been obvious to one having ordinary skill in the art, before the effective filing date of the claimed invention, to employ Brown's known nickel precursor in the modified Xie/Eugene ethylene-oligomerization process because Brown teaches that such nickel compounds are suitable catalyst precursors for the same ethylene-oligomerization reaction, with a reasonable expectation of successfully producing α-olefins.
Response to Arguments
Applicant's arguments have been fully considered but are not persuasive.
Applicant argues that Xie's reactor does not satisfy the claimed central-pipe arrangement because guide tube 35 is positioned above the liquid level. The rejection, however, does not rely solely upon guide tube 35 as the claimed central pipe. Xie's complete jet-loop circulation arrangement includes the central guide pipe through which the gas/liquid mixture descends and the surrounding annular region through which the mixture returns upward. Xie expressly describes the liquid jet entraining ethylene, formation of a gas/liquid mixture, downward flow through the central region and return through the surrounding annular region, while unreacted gas entering the headspace is recycled to the reaction stream (Xie, Fig. 1; col. 4, line 54–col. 5, line 53). Accordingly, the claimed internal circulation arrangement is taught by Xie when its disclosure is considered as a whole.
Applicant further argues that Xie does not teach a reactor “containing a gas phase and a liquid phase.” This argument is not persuasive. Xie expressly identifies a liquid level within the reactor and teaches that unreacted ethylene gas enters the space above the liquid level and is subsequently recirculated. Thus, Xie's operating reactor contains both a liquid phase and a gaseous phase.
Applicant argues that Xie does not disclose a degree of saturation of dissolved gaseous ethylene greater than 70.0%. The Examiner agrees that Xie does not expressly state the numerical saturation percentage. The rejection, however, is based on obviousness rather than inherency. Xie, as modified by Eugene, provides substantially the same gas/liquid ethylene-oligomerization process under overlapping temperature and pressure conditions, including vigorous liquid-jet entrainment of high-pressure ethylene, internal gas/liquid circulation and recycling of unreacted ethylene. The degree to which ethylene is dissolved in the liquid phase is an operating condition affecting the availability of ethylene for liquid-phase catalytic oligomerization. It would therefore have been within the level of ordinary skill to operate the modified process at a degree of saturation greater than 70% to provide sufficient dissolved ethylene for reaction and improve conversion. No evidence has been presented showing that 70% constitutes a critical threshold or that operation immediately above 70% produces an unexpected result relative to operation immediately below 70%.
Applicant argues that substituting Eugene's nickel/chromium catalyst for Xie's trialkyl-aluminum system would destroy Xie's intended purpose or principle of operation because Xie's disclosed downstream replacement and recycle stages depend upon the trialkyl-aluminum chain-growth chemistry. The argument is not persuasive because the rejection does not require bodily incorporation of Eugene's catalyst into every downstream feature of Xie's preferred overall process. Xie establishes the suitability of the disclosed jet-loop gas/liquid reactor configuration for high-pressure ethylene oligomerization and gas/liquid circulation, while Eugene establishes that nickel- and chromium-based catalytic systems were known for oligomerization of ethylene to α-olefins. The claimed invention does not require Xie's downstream replacement reaction or recycle of trialkyl aluminum. A person of ordinary skill seeking to conduct the known Eugene ethylene-oligomerization chemistry in a reactor providing effective gas/liquid contact would have had reason to employ Xie's known gas/liquid circulation arrangement. The modification therefore does not require maintaining the portions of Xie's process that are peculiar to trialkyl-aluminum replacement chemistry.
Applicant's reliance on the principle-of-operation doctrine is therefore unpersuasive because the relied-upon principle of Xie's reactor—high-pressure gas/liquid contacting and internal circulation—is preserved. The modification changes the known catalytic chemistry used to perform the oligomerization recited by the claim; it does not render Xie's gas/liquid circulation apparatus inoperative for contacting gaseous ethylene with a liquid reaction medium.
Regarding claim 4, Applicant argues that Zheng does not disclose apertures extending over only 5–10% of the lower portion of the central pipe. This argument is moot with respect to the present rejection. Claim 4 is written in the alternative and is satisfied where the central pipe has a solid wall over its entire height. Xie's central guide pipe provides the solid-wall alternative. Therefore, it is unnecessary for Zheng to disclose the alternatively claimed 5–10% aperture arrangement.
Regarding claim 7, Applicant argues that Hochman does not expressly disclose the claimed deflector spacing of one to two times the equivalent diameter of the central pipe and instead describes a different dimensional relationship (Hochman, col. 3, lines 15–18). The argument has been considered. Hochman is relied upon for the known use and positioning of a flow deflector adjacent the end of a draft tube and for recognition that the relative spacing and dimensions of the draft tube and deflector are selected to control and redirect circulating flow. Once the deflector of Hochman is applied to Xie's central circulation pipe, selection of an operative spacing relative to pipe diameter constitutes optimization of a known dimensional relationship to obtain adequate flow area and redirection without excessive restriction. Applicant has not established that the claimed 1–2 diameter range is critical or produces an unexpected result.
Regarding claims 13–14, to the extent Applicant argues that Koppehele describes gas atomizing liquid rather than liquid shearing gas bubbles, the rejection does not require Koppehele expressly to describe the identical operating orientation. Koppehele supplies the known structural arrangement of adjacent gas and liquid injection passages whose discharged streams interact under shear. The apparatus is capable of gas/liquid shear and is not structurally restricted to one of the fluids being the continuous phase. When that known injector arrangement is employed within the liquid phase of Xie's gas/liquid reactor, with gaseous ethylene and liquid supplied through the respective passages, the interacting streams predictably produce shear and gas dispersion into smaller bubbles. Thus, the functional limitation that the liquid injection “can reduce the size of the gas bubbles by shear” does not distinguish the claimed injector structure from the predictable use of Koppehele's known gas/liquid mixing structure in Xie's reactor.
Applicant's arguments concerning claims 21-23 have also been considered. The present rejection expressly addresses these claims. JP 2009-088078 teaches concentric annular gas/liquid discharge arrangements, and it would have been obvious to employ that known configuration in Xie's gas/liquid injection system to obtain circumferentially uniform gas/liquid interaction and improved dispersion. Claims 21-23 therefore remain rejected for the reasons stated above.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TAM M NGUYEN whose telephone number is (571)272-1452. The examiner can normally be reached Mon - Frid.
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/TAM M NGUYEN/ Primary Examiner, Art Unit 1771
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