DETAILED ACTION
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 4/20/26 was filed after the mailing date of the Notice of Allowance on 1/7/26. The submission is in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after allowance or after an Office action under Ex Parte Quayle, 25 USPQ 74, 453 O.G. 213 (Comm'r Pat. 1935). Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, prosecution in this application has been reopened pursuant to 37 CFR 1.114. Applicant's submission filed on 4/20/26 has been entered.
Upon further consideration of the provided IDS and search, a non-final rejection follows.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-3, 6-17, and 24-31 are rejected under 35 U.S.C. 103 as being unpatentable over Sushkeavich EA 037702 B1 (translation previously provided) in view of Van der Borght “First-Principles-Based Simulation of an Industrial Ethanol Dehydration Reactor” Catalysts 2019, 9, 921 and in view of Tirtowidjojo et al. US Publication 2011/0087056.
Regarding claim 1 and 28, Sushkeavich teaches a process comprising:
a) reacting a feed of ethanol and acetaldehyde in a reactor to produce 1,3 butadiene (page 2, 5th paragraph) wherein
b) the process comprises an multi-bed reaction zone (Figure 3). In page 1 end of first paragraph the heat transfer is maintained with efficiency by supplying hot catalyst to the moving stream with heat exchangers between the reactors.
Sushkeavich does not teach a tubular bed fixed bed reactor comprising adiabatic zones, however does teach that butadiene synthesis from ethanol was known to be carried out using fixed bed reactors as shown in Example 2. Sushkeavich also teaches that heat transfer is an important reactor-design consideration in butadiene synthesis.
Van der Borght teaches a fixed multi-bed adiabatic reactor for the dehydration of ethanol which has shown to be economically viable (abstract, section 1, paragraphs 1-2, and page 3 paragraphs 1-2). Van der Borght further teaches that tubular bed reactors are easy to operate though has their disadvantages thus resulting in a shift toward adiabatic fixed bed reactors (section 1, end of 2nd paragraph). Although Van der Borght does not explicitly teach fixed tubular bed reactors with adiabatic zones, Tirtowidjojo teaches the benefits of using an adiabatic tubular reactor for use in continuous gas phase reactions ([0022]) and minimizes heat transfers to and from the reactor ([0034]).
Therefore, it would have been obvious to one having ordinary skill in the art to modify the fixed-bed butadiene synthesis reactor in Sushkeavich to use a tubular fixed-bed reactor having adiabatic reaction zones, as suggested by Van der Borght and Tirtowidjojo. One having ordinary skill in the art would have been motivated to use this arrangement because adiabatic fixed-bed reactors and adiabatic tubular reactors were known and beneficial for gas-phase reactions. Furthermore, the modification would have provided predictable benefits including easier operation, lower cost, and reduced heat transfer to or from the reaction zones.
Regarding claims 2 and 3, Sushkeavich teaches at least 40 wt% ethanol, in an amount between 70 to 90 wt% ethanol (page 2 5th paragraph). This allows between 10 to 30 wt% of acetaldehydes, and thus at least 12.5 wt% (claim 3).
Regarding claim 6, the temperature of the butadiene reactor is between 280 and 350 ⁰C, thus overlapping the claimed range.
Regarding claim 7 and 24, the reactors comprise a supported catalyst (abstract) and operate in a pressure of 1.2 bar (Example 1).
Regarding claims 8, 25, 26, 30 and 31 the process comprises at least 4 (n=4) adiabatic reactors with supported catalyst to produce 1,3-butadiene, where at least part of the effluent from a reactor is fed to the subsequent reactor in the series (Figure)(effluent from n-1th reactor is fed to the nth reactor).
Regarding claims 9 and 27, Sushkeavich does not explicitly teach wherein composition and flow rate of the additional feed are adjusted so as to obtain a molar ratio of ethanol to acetaldehyde in the feed to the nth adiabatic reaction zone comprising a supported catalyst and producing 1,3-butadiene that is equal to 85-115% of the molar ratio of ethanol to acetaldehyde in the feed to the (n - 1)th adiabatic reaction zone comprising a supported catalyst and producing 1,3-butadiene.
However, since the molar ratio is a result effective variable, one having ordinary skill in the art would be motivated to easily producing 1,3-butadiene that is equal to 85-115% of the molar ratio of ethanol to acetaldehyde in the feed to the (n - 1)th adiabatic reaction zone by routine experimentation.
Regarding claims 10, Sushkeavich does not explicitly teach wherein the WHSV in an adiabatic reaction zone comprising a supported catalyst and producing 1,3-butadiene is adjusted such that the molar ratio of ethanol to acetaldehyde in the effluent from this adiabatic reaction zone comprising a supported catalyst and producing 1,3-butadiene is at least 20% higher than the molar ratio of ethanol to acetaldehyde in the feed to this adiabatic reaction zone.
However, the WHSV is considered a result effective variable and it would be within ordinary skill in the art to optimize the WHSV and produce 1,3-butadiene is at least 20% higher than the molar ratio of ethanol to acetaldehyde by routine experimentation.
Regarding claims 11, 12, and 13, the process includes at least two adiabatic reactor zones comprising a supported catalyst and produce 1,3 butadiene (Figure, abstract). There is a heat exchanger in between thus is considered the non-reaction zone (claim 12), where part of the effluent from one reactor passes through the heat exchanger before entering the next reactor (claim 13).
Regarding claim 14, acetaldehyde is continuously fed into the reactor to maintain about 1-10 wt% of acetaldehyde in Example 1. Thus, it is considered that additional acetaldehyde is fed to the reactor.
Regarding claim 15, the acetaldehyde is maintained at about 1-10 wt% of acetaldehyde in Example 1, but the ratio of the additional feed is not given. However, it would be obvious to one having ordinary skill in the art to vary the ratio by routine experimentation, since it is a result effective variable, and arrive at 0.1 to 5 ratio, 1 to 2, or 1.4 to 1.8.
Regarding claims 16 and 17, the process comprises at least 4 adiabatic reactors with supported catalyst to produce 1,3-butadiene, where at least part of the effluent from a reactor is fed to the subsequent reactor in the series (Figure). There is a heat exchanger in between where part of the effluent from one reactor passes through the heat exchanger before entering the next reactor (claim 17).
Regarding claim 29, providing inert packing is known in fixed reactors as taught in Van der Borght section 3.1.1.
Claims 4, 22, and 23 are rejected under 35 U.S.C. 102(a)(2) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious the aforementioned above and in view of Cadran et al. US Patent 10,792,644.
Regarding claim 4, 22, and 23, Sushkeavich does not explicitly teach using a tantalum catalyst. However, Cadran teaches a conversion process of ethanol and acetaldehyde to 1,3 butadiene using a catalyst that comprises tantalum in an amount that ranges from about 00.1 to 30 wt%. The tantalum catalyst has been found to increase 1,3-butadiene selectivity when reacting ethanol and acetaldehyde compared to catalyst that didn’t have tantalum (column 28 table).
Thus, it would have been obvious to one having ordinary skill in the art to modify Sushkeavich by using the tantalum catalyst in Cadran because the modification has been shown to provide a significant increase in 1,3-butadiene selectivity when reacting ethanol and acetaldehyde. Sushkeavich indicates that any suitable solid catalyst may be used in their process, so one having ordinary skill in the art can expect a reasonable amount of success with this combination of Sushkeavich and Cadran.
Conclusion
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/SHARON PREGLER/Primary Examiner, Art Unit 1772
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