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 1-15, 17, and 32 are ejected under 35 U.S.C. 103 as being unpatentable over Cheng et al. (US 2009/0134065 A1) in view of Mazanec et al. (US 2014/0303414 A1).
Cheng discloses a deep fluidized catalytic cracking process (DCC) wherein a hydrocarbon feed is contacted with a cracking catalyst to produce olefins (e.g., propylene) and spent catalyst is then separated and regenerated to burn off coke (carbon content) to restore the activity of the catalyst to produce a regenerated catalyst. The regenerated catalyst is then recirculated back to the cracking zone to contact with the hydrocarbon feed. The catalyst/additive comprises pentasil zeolite (e.g., ZSM-5), 0.7 to about 4 wt. % (e.g., 1.6 and 2.4 %) of iron oxide, and 5-20 wt.% of phosphorous (e.g., P2O5) and has an average particles size from about 20 – 200 microns. The catalyst can be comprised an additional catalyst (e.g., X or Y zeolite). See [0018], [0035], [0044], [0072], [0098], [0100], [0102], [0122]; tables 1, 2, 6.
Cheng does not teach an amount of coke on a regenerated catalyst.
Mazanec discloses a cracking process including a regenerating step to produce a regenerated catalyst comprising about 250 ppm (.025 wt.% ) to 0.3 wt. % coke (carbon content). See [0059].
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to apply Mazanec’s teachings regarding controlled oxidative regeneration to Cheng’s FCC pentasil catalyst system in order to regulate the amount of residual coke remaining on the regenerated catalyst. Residual coke level on regenerated FCC catalyst is a recognized operational variable that affects catalyst activity and heat balance in fluid catalytic cracking systems. Mazanec teaches that the oxidative regenerator can be operated under controlled conditions to achieve specific residual coke levels, including values within the claimed range (250 ppm to 0.3 wt.%). A person of ordinary skill in the art would have reasonably expected that controlling regenerator severity to achieve such coke levels would optimize catalyst performance and process efficiency in an FCC system such as that of Cheng.
Cheng does not teach the regenerated catalyst exhibits a Davison Attrition Index (DI) of less than 5. However, the catalyst of Cheng is essentially the same as the claimed catalyst. It would be expected that catalyst of Cheng would have an attrition resistance DI as claimed.
Cheng does not teach that the product stream comprises propylene in an amount of at least 10 wt. %.
It would have been obvious to one having ordinary skill in the art to optimize the known pentasil FCC system of Cheng by controlling regeneration severity and residual coke level as taught by Mazanec in order to enhance light olefin production, including propylene yield, because propylene yield is a recognized result-effective variable in FCC processes and was a known objective of pentasil additive use.
Response to Arguments
Applicant’s remarks have been fully considered but are not persuasive for the reasons set forth below.
Applicant argues that Mazanec is directed to catalytic pyrolysis of biomass rather than catalytic cracking of hydrocarbons and therefore a person of ordinary skill in the art would not have reasonably expected the effects of residual coke in Mazanec to translate to the FCC process of Cheng. However, the rejection does not rely on Mazanec for teachings regarding biomass conversion chemistry. Rather, Mazanec is relied upon for teachings directed to oxidative regeneration of catalyst particles and the control of residual coke remaining on regenerated catalyst. Residual coke level on regenerated catalyst is a recognized operational parameter in fluidized catalyst systems because residual coke affects catalyst activity, heat balance, and catalyst selectivity. Mazanec expressly teaches controlling regenerator operation to achieve specific residual coke levels, including 0.3 wt.%, 0.2 wt.%, 0.1 wt.%, 1000 ppm, and 250 ppm or less (Mazanec ¶[0059]), all of which fall within the presently claimed range of about 0.005 wt.% to about 0.30 wt.%.
Applicant further argues that Mazanec teaches that catalyst performance is unaffected at coke levels up to 0.59 wt.% and therefore a person of ordinary skill in the art would not have expected improved performance within the presently claimed coke range. This argument is not persuasive. Mazanec does not criticize, discredit, or discourage operation within the claimed coke range. Rather, Mazanec expressly identifies coke levels within the presently claimed range as workable embodiments. The mere disclosure that higher coke levels may still provide acceptable conversion in a biomass pyrolysis system does not constitute a teaching away from lower coke levels. Furthermore, optimization of residual coke level in FCC regeneration systems represents routine optimization of a recognized result-effective variable.
Applicant additionally argues that regeneration severity is not a result-effective variable below 0.59 wt.% coke because Mazanec allegedly shows equivalent performance between catalysts having 0.00 wt.% and 0.59 wt.% coke. However, the rejection does not rely on Mazanec as teaching the precise performance relationship asserted by Applicant. Rather, Mazanec teaches that regenerator operating conditions may be controlled to achieve specific residual coke levels, including levels squarely within the claimed range. A person of ordinary skill in the art would have reasonably understood that residual coke level is adjustable through regenerator severity and would have reasonably expected catalyst performance and selectivity to vary as regeneration conditions and residual coke are optimized in FCC systems.
With respect to the limitation requiring iron oxide “primarily in an oxidized state,” Applicant argues that not all regeneration processes inherently result in oxidized iron because coke may act as a reductant. However, Cheng expressly employs iron oxide-containing pentasil additives, and Mazanec teaches oxidative regeneration conditions for regenerated catalyst particles. Under oxidative FCC regeneration conditions, iron present as iron oxide would inherently be predominantly present in an oxidized state. Applicant has not provided evidence demonstrating that the ordinary oxidative regeneration conditions taught by the prior art would result in predominantly reduced iron species.
Applicant further argues that the claimed process achieves unexpected results due to the combination of the claimed iron oxide range and carbon range. Applicant relies on Fig. 3 and related examples to argue that propylene performance decreases above about 0.30 wt.% coke. However, Applicant’s evidence is not commensurate in scope with the breadth of claim 1. The claims encompass a wide variety of FCC operating conditions, feedstocks, catalyst inventory compositions, and additive concentrations, whereas the relied-upon examples are limited to specific ACE testing conditions, specific catalyst blends, and specific feedstocks. Applicant has therefore not established that the alleged unexpected results would occur across the full scope of the presently claimed invention.
Regarding the limitation that the product stream contains propylene in an amount of at least 10 wt.%, Cheng teaches pentasil-containing FCC additives for increasing light olefin production, including propylene. Propylene yield in FCC systems is a recognized result-effective variable influenced by catalyst composition, additive concentration, regeneration severity, and residual coke level. Mazanec teaches controlling regeneration conditions to achieve specific residual coke levels within the claimed range. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to optimize the known pentasil FCC system of Cheng using the regeneration teachings of Mazanec in order to enhance propylene yield, because increasing light olefin production was an expressly recognized objective of the prior art. Achieving a propylene content of at least 10 wt.% therefore represents the predictable result of routine optimization of known FCC process variables and does not constitute a patentably distinguishing limitation.
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.
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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