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.
Claims 1–8 and 11–12 is/are rejected under 35 U.S.C. §103 as being unpatentable over Allman et al. in view of Kraptchetov et al. and further in view of Taheri et al.
Claim 1
Allman teaches an integrated process for producing methyl methacrylate in which:
Ethylene is hydroformylated with carbon monoxide and hydrogen to produce propionaldehyde. Allman ¶¶25–28 and 34.
Propionaldehyde is reacted with formaldehyde to produce methacrolein. Allman ¶¶25 and 29–30, and ¶¶35–36.
Methacrolein is reacted with methanol and oxygen in the presence of a heterogeneous catalyst to produce methyl methacrylate by oxidative esterification. Allman ¶¶25 and 31–32, and ¶¶37–38.
The propionaldehyde/formaldehyde reaction is performed at approximately 1.0–3.0 atmospheres, and more specifically at 1.5–2.5 atmospheres. The expressly preferred range is therefore above 1 bar. Allman ¶30.
The oxidative esterification is conducted in a stirred-tank reactor with methanol, oxygen, and a suspended heterogeneous catalyst. Allman ¶¶31–32.
Allman expressly states that oxidative esterification is “ideally suited” for incorporation into the propionaldehyde-formylation process. Allman ¶¶22–23. Allman does not expressly teach producing its ethylene from ethanol or the particular average methacrolein and methanol/methacrolein limitations.
Kraptchetov teaches the same terminal oxidative esterification of methacrolein with methanol and oxygen in a liquid phase over a heterogeneous noble-metal catalyst. Kraptchetov discloses:
A continuous tubular reactor or continuous stirred-tank reactor containing a fixed catalyst bed and oxygen gas. Kraptchetov, p. 4, l. 29–p. 5, l. 8.
Gold or palladium as the noble metal, preferably gold. Kraptchetov, p. 3, ll. 23–33.
An average methacrolein concentration no greater than 40 wt%. Kraptchetov, p. 5, ll. 29–30.
Outlet oxygen concentrations of 0.5–7 mol%, including preferred ranges of 2–6.5 and 3–6 mol%. Kraptchetov, p. 6, ll. 1–3.
Example 1 employing a 20-wt% methacrolein feed, balance methanol, a 1.5-wt% gold catalyst, and vent oxygen of 4–5 mol%. The reported average methacrolein concentrations are 8.6–18.5 wt%. Kraptchetov, p. 6, ll. 1–18 and Table.
The no-recycle Example 1 run provides the following calculation on the basis required by claim 1:
Feed: 20 g methacrolein and approximately 80 g methanol.
Methacrolein conversion: 76%, leaving 4.8 g methacrolein.
Stoichiometric methanol consumption for 15.2 g methacrolein is approximately 6.9 g, leaving approximately 73.1 g methanol.
Outlet concentration on a methanol-plus-methacrolein basis is therefore approximately 6.2 wt% methacrolein and 93.8 wt% methanol.
Average methacrolein concentration: (20+6.2)/2=13.1 wt%, which is less than 40 wt%.
Average methanol-to-methacrolein weight ratio: [(80+93.8)/2]÷[(20+6.2)/2] ≈ 6.6:1, which is less than 20:1.
It would have been obvious to substitute Kraptchetov’s known continuous gold-catalyzed oxidative esterification for the oxidative-esterification stage of Allman. Both references employ the same reactants, reaction, and MMA product, and Allman expressly identifies oxidative esterification as particularly suited to its propionaldehyde route. Kraptchetov supplies an improved continuous implementation having defined concentration and oxygen conditions. The modification would have predictably provided continuous operation, high MMA productivity, and the process-safety benefits identified by Kraptchetov.
Taheri teaches catalytic dehydration of ethanol to produce ethylene. Taheri describes ethanol dehydration as a known commercial source of ethylene, identifies renewable ethanol obtainable by fermentation of sugarcane, corn, cellulosic biomass, agricultural materials, and algae, and reports complete ethanol conversion with greater than 99% selectivity to ethylene. Taheri ¶¶5–8, 22 and 24–30.
It would have been obvious to obtain Allman’s ethylene feed using Taheri’s ethanol-dehydration process. Allman requires ethylene but does not condition its downstream reactions on how the ethylene was made. Taheri teaches ethanol dehydration as an alternative commercial ethylene supply, including a renewable supply, with high conversion and selectivity. The resulting ethylene performs the same hydroformylation function in Allman and would have produced the predictable result of propionaldehyde formation.
Claims 2–4
Kraptchetov’s Example 1 reports 4–5 mol% oxygen in the exiting vent gas. Kraptchetov, p. 6, ll. 11–13. That range falls within:
Claim 2: 1–7.5 mol%;
Claim 3: 2–7.25 mol%; and
Claim 4: 4 to less than 7 mol%.
The disclosed range therefore anticipates the selected portions of each claimed range and, at minimum, establishes prima facie obviousness under the overlapping-range doctrine.
Claim 5
Kraptchetov teaches a catalyst bed in a continuous tubular reactor and specifically identifies a trickle-flow fixed-bed reactor. Kraptchetov, p. 4, l. 29–p. 5, l. 8; p. 6, ll. 15–30.
Claim 6
Kraptchetov teaches that the noble metal preferably is gold and uses a 1.5-wt% gold-on-alumina catalyst in Example 1. Kraptchetov, p. 3, ll. 23–33; p. 6, ll. 4–7.
Claim 7
Kraptchetov’s Example 1 reports space-time yields of 3.2–8.2 mol MMA/kg catalyst·hour. The reciprocal gives: 1/8.2=0.122 to 1/3.2=0.313 kg catalyst for every gram-mole of MMA produced per hour. This entire range lies within the claimed 0.02–2 kg catalyst range. Kraptchetov, p. 6, Table.
Claim 8
The Example 1 catalyst contains 1.5 wt% gold. Multiplying the claim 7 catalyst quantities by 0.015 gives: 0.122(0.015)=0.00183 to 0.313(0.015)=0.00469 kg gold for every gram-mole of MMA produced per hour. These quantities lie within the claimed 0.0001–0.1 kg range. Kraptchetov, p. 6, ll. 4–7 and Table.
Claim 11
Taheri teaches ethanol obtained from renewable or sustainable resources, including sugarcane, corn, agricultural and cellulosic biomass, and algae-based feedstocks. Taheri ¶6. Selecting renewable ethanol for the combined process would have been expressly suggested by Taheri.
Claim 12
Allman explains that two carbon atoms in the methacrylic-acid portion of the MMA route originate from ethylene. Allman ¶19. MMA contains five carbon atoms after addition of the methanol-derived ester carbon. When Taheri’s renewable ethanol is converted to ethylene, the two ethanol-derived carbon atoms are retained in the ethylene and downstream MMA. Thus: 2/5=40% of the MMA carbon atoms are derived from renewable ethanol. Claim 12 therefore follows directly from the carbon balance of the combined process.
Claim 9—further in view of Worley
Claim 9 is/are rejected under 35 U.S.C. §103 as being unpatentable over Allman in view of Kraptchetov and Taheri, as applied above, and further in view of Worley.
Worley concerns the reaction product or effluent from oxidative esterification of methacrolein and methanol. Worley ¶¶1–3. Worley teaches an OER reaction product mixture containing 40–80 wt% methanol, preferably 50–68 wt% methanol. Worley ¶7. Example 1 expressly identifies an OER-derived mixture containing 58.1 wt% methanol, 29.9 wt% MMA, 2.1 wt% methacrolein, and 7.1 wt% water. Worley ¶16.
It would have been obvious to operate the Kraptchetov oxidative-esterification stage so that its exiting liquid retained at least 30 wt% methanol because:
1. Kraptchetov already teaches using excess methanol, producing unreacted methanol, and recovering and recycling methanol from the OER product; and
2. Worley expressly shows that conventional OER effluents contain 40–80 wt% methanol.
The claimed lower limit of 30 wt% is below Worley’s entire disclosed range. The selection therefore would have been expected to maintain a methanol-rich liquid reaction medium and facilitate downstream methanol recovery and recycle.
Claim 10—further in view of Herron
Claim 10 is rejected under 35 U.S.C. §103 as being unpatentable over Allman in view of Kraptchetov and Taheri, as applied above, and further in view of Herron.
Herron teaches liquid-phase oxidative esterification of methacrolein with methanol and oxygen over a supported noble-metal catalyst, preferably gold, in a continuous fixed-bed reactor. Herron ¶¶13–15 and 19. Herron identifies methyl isobutyrate as an undesirable OER byproduct. Herron ¶14.
Herron’s Example 1 reports MIB concentrations of 470, 480, 540, 670, 910, and 1,170 ppm, all below the claimed 5,000-ppm maximum. Herron ¶21 and Table 1. Those values are reported on a 100%-MMA-product basis. Because the total exiting liquid includes MMA plus methanol, methacrolein, water, and other components, MIB ppm calculated against the total exiting liquid can only be equal to or lower than the value calculated against MMA alone.
It would have been obvious to apply Herron’s outlet-oxygen and pH control to the combined OER process because Herron teaches that those conditions reduce formation of difficult-to-remove, odor-causing MIB while using the same reactants, catalyst class, and MMA-forming reaction. The resulting MIB concentration below 5,000 ppm would have been a predictable result.
Claim Objections
Claims 2-4 objected to because of the following informalities:
Corrections:
Claim 2: “ranging from 1 mol% to 7.5 mol%”
Claim 3: “ranging from 2 mol% to 7.25 mol%”
Claim 4: “ranging from 4 mol% to less than 7 mol%”
Appropriate correction is required.
Specification
The specification is objected to as failing to provide proper antecedent basis for the claimed subject matter. See 37 CFR 1.75(d)(1) and MPEP § 608.01(o). Correction of the following is required: The written description does not appear to expressly state claim 9’s “at least 30 wt% methanol based on the total weight of the liquid phase” limitation. Because that limitation was present in original claim 9, the original claim itself supplies written-description support.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DEBORAH D CARR whose telephone number is (571)272-0637. The examiner can normally be reached Monday-Friday (10:30 am -6:30 pm).
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/DEBORAH D CARR/Primary Examiner, Art Unit 1691
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