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 1–21 are rejected under 35 U.S.C. §103 as being unpatentable over Vermeiren et al., “Impact of Zeolites on the Petroleum and Petrochemical Industry,” Topics in Catalysis, Vol. 52, pp. 1131–1161 (2009) (“Vermeiren”) in view of Kuhlmann et al., US 5,463,160 (“Kuhlmann”).
Vermeiren discloses refinery processing of cracked naphtha and light naphtha streams, which inherently comprise C5 hydrocarbons, and teaches that such streams are subjected to hydrotreating (HDT) prior to downstream processing (see Fig. 3; §5.1). Vermeiren further teaches that the hydrotreated stream is passed to a separation system that fractionates the stream into lighter and heavier components, including C5/C6 fractions and heavier C7+ fractions (see Fig. 3; §5.1–5.2). Vermeiren additionally teaches a deisopentanizer (DIP) within a C5/C6 isomerization flowsheet (see Fig. 5; §5.2.2), wherein:
the DIP produces an i-C5 (isopentane) stream (overhead),
heavier components are separated into C6+ fractions (via downstream DIH separation), and
a C5 raffinate stream (n-C5 or mixed C5) is produced and routed to a reactor (isomerization unit) for further processing (see Fig. 5; §5.2.2).
Thus, Vermeiren teaches:
passing a feed comprising C5 hydrocarbons through hydrodesulfurization (HDT),
passing the resulting stream to a first separation assembly, and
passing a C5 fraction to a deisopentanizer producing:
an isopentane stream,
a heavier C6+ stream, and
a C5 raffinate stream,
and routing the raffinate stream to a reactor assembly.
However, Vermeiren does not explicitly teach producing isoamylene.
Kuhlmann discloses a process for producing isoamylenes via skeletal isomerization of C5
olefins (e.g., n-pentenes) over a zeolite catalyst (e.g., ferrierite) (see col. 9, lines 20–28; col. 10,
line 29 – col. 11, line 13).
Kuhlmann further teaches:
use of zeolite-based catalysts (e.g., ferrierite, see col. 3, lines 5–25),
C5 hydrocarbon feedstocks comprising pentenes (col. 9, lines 20–28), and
operating conditions including temperatures of 200–550 °C and pressures of 0.1–100 atm (claim 2; col. 8, lines 30–45).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the process of Vermeiren by subjecting the C5 raffinate stream to the skeletal isomerization process of Kuhlmann in order to convert olefinic components present in refinery-derived C5 streams into isoamylenes, which are known valuable intermediates for fuel blending and etherification (e.g., TAME production).
Vermeiren’s hydrotreating step reduces contaminants and olefin content, but does not require complete elimination of olefins, and refinery-derived C5 streams (including cracked and light naphtha) are well known to contain residual olefins. Accordingly, Vermeiren does not teach away from further processing of olefinic components.
Kuhlmann teaches operation at temperatures as low as 200 °C, which overlaps the claimed temperature range (100–210 °C). Selection of operating conditions within overlapping ranges would have been a matter of routine optimization (see MPEP §2144.05; In re Aller; In re Peterson). Further, Kuhlmann’s pressure range (0.1–100 atm, i.e., ~0.1–100 bar) encompasses and overlaps the claimed 10–30 barg, rendering the claimed pressure an obvious design choice.
Accordingly, the combination of Vermeiren and Kuhlmann teaches or renders obvious all limitations of claim 1.
Claim 2
Kuhlmann teaches separation of isoamylenes from unreacted C5 hydrocarbons (see col. 11, lines 5–13), and Vermeiren teaches recycle of C5 streams (Fig. 3; §5.1). Therefore, claim 2 is obvious.
Claim 3
Recycling C5 streams to upstream processing units (including cracking units) is a well-known refinery practice. Vermeiren teaches integration of streams across refinery units (Fig. 3; §5.1). It would have been obvious to recycle the C5 stream to a cracker furnace to improve overall yield.
Claim 4
Vermeiren does not explicitly disclose a recycle stream containing ≤16 wt.% isopentane. However, the composition of recycle streams is a result-effective variable governed by separation efficiency. Optimization of such composition is within the level of ordinary skill in the art (see In re Aller).
Claim 5
Kuhlmann does not explicitly disclose a product purity of 98–99.9 wt% isoamylene. However, purification of petrochemical streams to high purity (≥98%) via distillation is standard practice. It would have been obvious to produce isoamylene within this purity range.
Claim 6
Vermeiren does not explicitly disclose 68–75 wt% isopentane. However, DIP overhead composition is a predictable function of distillation equilibrium. Producing such a composition would have been obvious.
Claim 7
Vermeiren does not explicitly disclose the claimed DIP operating parameters. However, column design (number of stages, temperature, pressure) is a routine engineering choice. The claimed conditions fall within typical deisopentanizer operation ranges.
Claim 8
Vermeiren explicitly teaches cracked naphtha feed streams (Fig. 3; §5.1), which originate from cracker furnace effluent. Thus, claim 8 is taught.
Claim 9
Kuhlmann does not explicitly disclose preheating the raffinate stream. However, preheating feed to reactor temperature is standard practice to achieve reaction conditions and would have been obvious.
Claim 10
Vermeiren teaches hydrotreating of naphtha producing H₂S and light hydrocarbons (C4-) (Fig. 3; §5.1). Thus, claim 10 is taught.
Claim 11
Vermeiren does not explicitly disclose 15–28 wt.% C6+ hydrocarbons. However, the fraction of C6+ is a result-effective variable controlled by separation cut points and is an obvious optimization.
Claim 12
Vermeiren Fig. 5 shows fractionation columns with side draws. Withdrawal of raffinate from a side of the column is a standard distillation configuration.
Claim 14
Kuhlmann teaches conversion of pentenes to isoamylenes at high conversion levels (see Example 2; col. 10–11). Achieving ≥58 wt.% conversion would have been obvious.
Claims 15–20
Control of dienes/diolefins to ≤5 wt.% is standard to prevent catalyst deactivation and gum formation. Such limitations represent routine feed purification and are obvious.
Claim 21
The claimed composition (1–5 wt.% isopentane, 0–1 wt.% isoamylene, balance C5 hydrocarbons) represents a specific distribution within a refinery C5 stream. Such compositions result from known separation and conversion processes and are considered obvious optimizations.
RESPONSE TO APPLICANT’S ARGUMENTS
Applicant argues that:
Vermeiren removes olefins and therefore teaches away, and
Kuhlmann requires olefin feed and is incompatible, and
Temperature differences render the combination improper.
These arguments are not persuasive.
First, Vermeiren’s hydrotreating step reduces olefin content but does not require complete elimination of olefins. Refinery-derived C5 streams are known to contain residual olefins, particularly in cracked naphtha streams. Thus, Vermeiren does not teach away from further processing of olefinic components.
Second, Kuhlmann teaches skeletal isomerization of C5 olefins to isoamylenes, which is directly applicable to olefinic components present in refinery streams. Applying a known conversion process to a known feedstock component constitutes a predictable use of prior art elements.
Third, Kuhlmann explicitly teaches operation at 200 °C, which overlaps the claimed range. Optimization within overlapping ranges is presumed obvious.
Conclusion
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