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 1-11 are rejected under 35 U.S.C. 103 as being unpatentable over Chapus et al. (US 2017/0022424 A1) in view of either in view of either Toppinen et al. (WO-2020165496 A1) or Himelfarb et al. (US 2008/0004476 A1).
Chapus teaches a fixed-bed trickle-flow hydroprocessing reactor for treating renewable feedstocks comprising triglycerides and/or fatty acids in the presence of hydrogen, wherein:
Feed and hydrogen are introduced into a fixed-bed reactor and flow downward through at least one catalyst bed under hydroprocessing conditions to cause hydrodeoxygenation, hydrogenation, decarboxylation, hydrodenitrogenation, and cracking reactions, yielding paraffinic hydrocarbons. See ¶[0013]–[0042], [0058], [0065]–[0068], [0090]–[0100], [0110]–[0116].
The process is operated as a downward co-current trickle bed with staged catalytic zones, recycle, interbed quenching, and temperature control to prevent hot spots and maintain catalyst stability. See ¶[0065]–[0093], [0110]–[0116].
Effluent from a first catalyst bed is quenched and redistributed to a second bed using interbed devices and quench mixing, optionally by internal or external heat exchangers, separators, and recycle streams. See ¶[0075]–[0088], [0090], [0096], [0110]–[0113], [0116]–[0129].
Quenching may be accomplished by quench gas, quench liquid, liquid recycle, or heat-exchange cooling, and redistribution devices are employed to maintain uniform temperature and catalyst performance. See ¶[0075]–[0088], [0096], [0110]–[0113].
Chapus defines TRₙ on a weight ratio basis (g/g) less than 2 (e.g., 1.8) and for typical renewable diesel liquids, density ≈ 0.75–0.85 g/mL; converting weight to volume will keep the numerical ratio in basically within the claimed volume ratios. See ¶[0030], [0031] and example 2.
Chapus does not explicitly teach that the downward flow in a manner such that the top surface is uniformly wetted across the reactor cross section (at least 90% of top surface), and does not teach that the quench effluent over that reactor cross section is less than 25% of the average temperature drop caused by the quenching.
Both Toppinen and Himelfarb disclose a downward flowing reactor which comprising distributors so that feedstocks are uniformly distributed the top surface area of catalyst bed. It would be expected that the catalyst bed is uniformly wetted when at least 90% of the top surface is contacted. The reactors comprises a plurality of nozzles and utilizing a quenched gas. Himelfarb also teaches that effluent 244 is quenched by using heat exchanger 244. Since both Toppinen and Himelfarb teach the quench is thoroughly mixed in device 101, it would be expected that the device would provide a homogeneous as claimed. (See Toppinen: page 5, lines 25 through page 6, line 25, figure 1 (118, 122, 120); Himelfarb: Figure 3 (214); [0052]).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Chapus by utilizing a reactor having distributers as suggested by either Toppinen or Himelfarb because such distributer is known to be effective to evenly distributed feedstock over a catalyst bed, prevent maldistribution, reduce hot-spot formation, improve exotherm control, and increase catalyst utilization.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have modified the process of Chapus by having the quench effluent over that reactor cross section is less than 25% of the average temperature drop caused by the quenching because Chapus teaches using quench streams to control the reactor’s temperature and one of skill in the art would acknowledge that the reactor vessel have to maintain at certain operating temperatures so that the reaction would occur at a desirable rate. Therefore, it is within the level of one of skill in the art to have the quench effluent over that reactor cross section is less than 25% of the average temperature drop caused by the quenching to maintain the reaction rate.
Response to Arguments
Applicant relies heavily on Figures 1A–1E and 2D–2E of the present application to distinguish the claimed “uniform wetting,” asserting that the prior art only provides localized wetting (e.g., 15–30% surface coverage) whereas the claimed invention achieves ≥90% coverage with ≤10% velocity variation. This argument is not supported by the cited references. Himelfarb teaches distributing hydrocarbon liquid across the top surface of a catalyst bed using distribution trays with multiple openings/nozzles arranged across the reactor cross-section, with the express objective of achieving substantially uniform flow and minimizing radial non-uniformity (see, e.g., ¶¶0006–0009, 0016–0017 and Figs. 1–3) . Such multi-point distribution inherently results in broad surface coverage and overlapping flow regions, contrary to Applicant’s characterization of the prior art. Applicant’s figures merely illustrate a degree of improved distribution performance, not a structurally distinct distribution system.
The claimed “uniform wetting” is a performance-based limitation, not tied to any specific structural configuration. The claims do not require a particular nozzle geometry, tray design, or distributor configuration that would inherently produce the recited wetting metrics. Rather, the limitation reflects the result of distributing liquid over a catalyst bed. It is well established that uniform liquid distribution across catalyst beds is a fundamental design objective in trickle-bed and hydrotreating reactors to avoid channeling, hot spots, and catalyst deactivation. The numerical thresholds (≥90% coverage, ≤10% velocity variation) therefore represent optimization of a known result-effective variable (distribution uniformity).
Applicant further argues that Chapus relies on staged injection and hydrogen distribution to manage exothermicity, and therefore does not teach or suggest uniform wetting. This is not persuasive. Chapus teaches multi-bed hydrotreating reactors, downward flow, recycle streams, and temperature control strategies for renewable feedstocks, all addressing the same underlying engineering concerns of exotherm management, catalyst utilization, and flow distribution. The use of staged injection does not teach away from improving hydrodynamic distribution; rather, such techniques are complementary. A person of ordinary skill in the art would have recognized that improving liquid distribution (as taught by Himelfarb or Toppinen) would further enhance the performance of Chapus’s system in a predictable manner.
Applicant contends that Toppinen is directed only to mixing below the bed and cannot be used to suggest distribution across the top surface of a catalyst bed. This argument is not persuasive. Toppinen teaches conditioning fluid streams to achieve uniform composition, temperature, and flow prior to entering downstream catalyst zones, within the context of trickle-bed reactors. Fluid mixing and distribution are closely related hydrodynamic functions, and the teachings of Toppinen regarding flow uniformity and avoidance of localized gradients would have been readily applied by a person of ordinary skill in the art to improve distribution across catalyst beds in Chapus. The rejection does not rely on a literal relocation of a specific device, but on the transfer of known flow-uniformity principles.
Applicant further argues that Himelfarb represents only “conventional” distribution trays and does not teach the claimed invention. This is not persuasive. Even if considered conventional, Himelfarb expressly teaches full cross-sectional distribution and minimization of radial non-uniformity, which corresponds to the same objective as the claimed uniform wetting. The claims do not recite any structural distinction over such trays, but instead recite a level of performance, which would have been achieved through routine optimization of known distributor designs.
With respect to the recycle ratio, Applicant argues that Chapus discloses only weight-based ratios, whereas the claims require a volume-based ratio. This argument is not persuasive. As confirmed by the present specification, both the recycled liquid and the renewable feedstock are hydrocarbon liquids. Such liquids have similar densities within a narrow and predictable range typical of renewable diesel systems, such that a ratio expressed on a mass basis inherently corresponds to a numerically similar volume ratio within normal process tolerances. Chapus discloses recycle ratios ≤2, including values around 1.5–1.8, which overlap the claimed range of 0.4:1 to 1.8:1. The expression of the ratio on a volume basis instead of a weight basis constitutes a routine engineering choice and unit conversion, not a patentable distinction.
Finally, Applicant’s assertion of impermissible hindsight is not persuasive. The rejection combines Chapus (hydroprocessing of renewable feedstocks with recycle and temperature control) with Himelfarb/Toppinen (fluid distribution and flow-uniformity techniques), each addressing well-known challenges in catalytic reactor operation. The combination merely applies known techniques to improve known systems with predictable results, consistent with KSR.
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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