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 .
Information Disclosure Statement
2. The information disclosure statement filed 2/29/2024 fails to comply with 37 CFR 1.98(a)(3) because it does not include a concise explanation of the relevance, as it is presently understood by the individual designated in 37 CFR 1.56(c) most knowledgeable about the content of the information, of each patent listed that is not in the English language. It has been placed in the application file, but the information referred to therein has not been considered.
Claim Rejections - 35 USC § 103
3. 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.
4. 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.
5. Claims 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Zhang et al., International Publication No. WO/2020/162876 (hereinafter referred to as Zhang).
Regarding claims 1-20, Zhang discloses a process for preparing cresols. A phenols containing stream is first separated in a stream comprising phenol, a stream comprising heavy methyl phenols and heavy alkyl phenols and a stream comprising cresols. The heavy alkylphenols are then dealkylated to form an effluent stream comprising phenol, cresols, heavy methyl phenols and olefins, which is then transalkylated after separation of at least the olefins. Zhang further discloses the use of benzene (see Claim 14 of Zhang) and phenol in (see Claim 15 of Zhang).
Zhang discloses a process that largely overlaps with the present process but using different terminology for various components and reaction steps. The present application discloses two transalkylation steps performed on an alkyl phenol stream. One is performed in the presence of benzene and/or toluene and the other in the presence of phenol. In claim 1 of Zhang the first step is referred to as a dealkylation but Zhang discloses in claim 14 and on page 3 in lines 22-23 and on page 6 in lines 9-11 that this step can be performed in the presence of benzene with molar ratios of 0.1:1 to 10:1 for the benzene to alkylphenol ratio. The present application discloses in [0019] a molar ratio of benzene or toluene to alkylphenols in the range of 1-20. The transalkylation step with benzene is contemplated in Zhang with largely overlapping component ratios. Zhang further discloses the isolation of an alkene in (see Claim 1 of Zhang) but from the description it becomes clear that these compounds are not necessarily formed if a significant excess of benzene is used as an alkyl acceptor. This must lead to an alkylaromatic stream, which is seen as implicitly disclosed.
Zhang discloses on page 8 line 4-29 referring to figure 1: the extracted phenol stream 145 comprises phenol and alkylphenols. The extracted phenol stream 145 is sent to the second fractionation zone 125 where it is separated into a heavy alkylphenol stream 150 comprising heavy alkylphenols and heavy methylophenols, a phenol stream 155 comprising phenols, and a cresols stream 160 comprising cresols. The heavy alkylphenol stream 150 is fed to a dealkylation reaction zone 165. The reaction conditions are controlled so that mainly alkyl groups with two or more carbons are removed, while methyl and hydroxyl groups remain. A steam stream 170 is fed to the dealkylation reaction zone 165 to maintain catalyst activity. The dealkylation effluent 175 comprises phenol, heavy methyl phenols, and olefins, as well as unreacted heavy alkylphenols. The dealkylation effluent 175 is sent to a dealkylation separation zone 180 where it is separated into an olefin stream 185 comprising olefins and second stream 190 comprising phenol, heavy methylphenols, and unreacted heavy alkylohenols. The dealkylation effluent 175 may also contain water, which can be separated out as water stream 195 and recycled to the dealkylation reaction zone 165. The second stream 190 is sent to the transalkylation reaction zone 200, along with phenol stream 155. Optionally, depending on the content of methyl groups in the heavy methyl phenols, a fresh phenol stream 205 can be sent to transalkylation reaction zone 200, if needed. There should be enough phenol to react with the heavy methyl phenols to form cresols. The transalkylation effluent stream 210 comprising cresols is sent to the separation zone 110 where it is combined with the extracted phenol stream 145 and sent to the second fractionation zone 125. Further processing of the cresols in cresol stream 160 can be done through purification using technology such as distillation, crystallization, and/or extraction to obtain higher value isomer, such as m-cresol.
Claim Rejections - 35 USC § 103
6. Claims 1-20 are rejected under 35 U.S.C. 103 as being unpatentable over Sharp et al., CA Publication No. CA910920A (hereinafter referred to as Sharp) in view of Huibers et al., US Patent No. 4,431,850 (hereinafter referred to as Huibers) and Keim et al., US Patent No. 4,554,388 (hereinafter referred to as Keim).
Sharp disclose a process for producing cresols that comprises dealkylation and transalkylation of a phenol containing feed stream (see entire disclosure, in particular page 1, lines 11-31; page 2, lines 7-30; page 3, lines 2-20). The dealkylation and transalkylation are conducted in the presence of a catalyst as required in claims 11- 13 and 18-20 (see lines 23-31). The phenol containing feed stream may comprise a coal tar feed stream as required in claim 15 (see page 2, lines 1-12 and page 4, lines 13-32). The process disclosed by Sharp can be conveniently carried out at temperatures in the range of 350-500°C, preferably in the range of from 400-470°C, which is within the claimed ranges disclosed in claims 11, 12, 18 and 19 for the claimed dealkylation and transalkylation reactions (see page 2, lines 13-14). The constitution of the product is influenced by the time of contact of the reactants, the proportion of phenol present in the feed stream and the reaction temperature (see page 2, line 20 to page 3, line 24). The process can sometimes be operated with advantage by using steam or hydrogen, as required in claim 14, in combination with the vaporized phenolic feedstock (see the sentence bridging pages 2 and 3 and page 3, lines 5-8). The proportion of cresols and xylenols present are dependent on the conditions used in and the efficiency of the primary distillation of the tar (see page 4, lines 13-26). The phenol formed in the dealkylation reaction is used to partially compensate the phenol used in the transalkylation reaction (see page 4, lines 26-29). When tar acids boiling below 240°C are used in the process, they are treated by steam-stripping to remove impurities that
boil below 230°C (see page 5, lines 3-11). However, when higher boiling tar acids are used in process a further purification stage, such as washing with low-boiling hydrocarbon solvents is required to remove hydrocarbon impurities (see page 5, lines 11-7). The reaction product is fractionated to obtain a phenol fraction, which can be recycled without purification and a fraction containing cresols, xylenols and other low- boiling phenols which can be purified by washing with a hydrocarbon solvent and the resulting pure cresols and xylenols separated by fractionation (see page 5, line 30 to page 6, line 7).
Sharp differ from the instant claims in that although Sharp appear to imply conducting distillation prior to carrying out the dealkylation reaction, Sharp do not expressly disclose separating the phenol containing feed stream into at least a phenol stream comprising phenol, an alkylphenol stream comprising heavy methyl phenol and heavy alkylphenols, as a cresols stream comprising cresols.
Huibers disclose a process wherein a mixture of mono and poly-alkylated phenols is subjected to a hydrodealkylation reaction wherein prior to the hydrodealkylation reaction a distillation step to remove excess phenol from the mixture of mono and poly-alkylated phenols is conducted in order to avoid losses due to dihydroxylation reactions (see summary of invention).
One having ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to separate the phenol containing feed stream of Sharp into at least a phenol stream comprising phenol, an alkylphenol stream comprising heavy methyl phenol and heavy alkylphenols, as a cresols stream comprising cresols, since Huibers disclose that in a process wherein a mixture of
mono and poly-alkylated phenols is subjected to a hydrodealkylation reaction prior to the hydrodealkylation reaction a distillation step is conducted to remove excess phenol from the mixture of mono and poly-alkylated phenols in order to avoid losses due to dihydroxylation reactions.
Sharp differ from the instant claims in that it is not required to conduct a separation step between the dealkylation and transalkylation steps. However, Sharp do teach controlling the proportions of phenol and higher alkylphenols to obtain a quantity, which will give the most advantageous product distribution (see page 2, lines 23-31). If necessary, the desired proportions can be obtained via a distillation (see page 2, lines 24-27).
One having ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious that one could separate the dealkylation effluent of Sharp by distillation prior to conducting the transalkylation in order to obtain a proportion of phenol and higher alkylphenols with a desired quantity, which will give the most advantageous product distribution leading to cresols.
Sharp further differ from claims 11 and 18 in that Sharp do not disclose the pressure and WHSV for use in the dealkylation reaction.
Huibers disclose a process wherein a mixture of mono and poly-alkylated phenols is subjected to a hydrodealkylation reaction at a temperature within the range of 900° to 1100°F (482.2°-593.3°C), a pressure within the range of 300 to 1600 psi (2.1 to 11.0 MPa), and a space velocity within the range of 0.2 to 3 Vi/hr/Vr, which are all within or overlap with the claimed ranges (see entire disclosure, in particular column 2, lines 36-65). The process allows for the mixture of mono and poly-alkylated phenols to be hydrodealkylated with improved selectivity for phenols (see summary of invention).
One having ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to carry out the dealkylation reaction of Sharp utilizing a temperature, pressure, and WHSV within the claimed range, since Huibers disclose that in a process wherein a mixture of mono and poly-alkylated phenols is subjected to a hydrodealkylation reaction a suitable reaction temperature is within the range of 900° to 1100°F (482.2°-593.3°C), a suitable reaction pressure is within the range of 300 to 1600 psi (2.1 to 11.0 MPa), and a suitable space velocity is within the range of 0.2 to 3 Vi/hr/Vr. Such reaction conditions will allow for the mixture of mono and poly-alkylated phenols to be hydrodealkylated with improved selectivity for phenols.
Sharp further differ from claims 12 and 19 in that Sharp do not disclose the pressure and WHSV for use in the transalkylation reaction.
Keim disclose a process for the transalkylation of alkylphenols and phenol- derivatives in the presence of a catalyst, wherein the reaction temperature is within the range of 200°-550°C), a pressure within the range of 1 to 300 bar (100 kPa to 30.0 MPa), and a residence time of within the range of 0.1 to 10 hrs, which are all within or overlap with the claimed ranges (see entire disclosure, in particular the Summary of the Invention). The feed for the transalkylation was a residue taken from a technical phenol alkylation unit, from with mono- and dimethylphenols had been essentially distilled off (see column 2, lines 61-64).
One having ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to carry out the transalkylation reaction of Sharp utilizing a temperature, pressure, and WHSV within the claimed range, since Keim disclose that in a process for the transalkylation of alkylphenols and phenol- derivatives in the presence of a catalyst a suitable reaction temperature is within the range of 200°-550°C, a suitable reaction pressure is within the range of 1 to 300 bar (100 kPa to 30.0 MPa), and a suitable residence time is within the range of 0.1 to 10 hrs.
Sharp differ from the instant claims in that Sharp do not disclose recycling the transalkylation effluent stream to the first separation zone.
Keim disclose working up of the reaction product of the transalkylation process can be carried out by conventional separation processes like distillation, extraction and crystallization (see column 2, lines 33-36) and the residue which remains after separation may be recycled to the isomerization and transalkylation process, leading to an almost complete conversion of the residue, optionally after having separated resinous material (see column 2, lines 36-40).
One having ordinary skill in the art before the effective filing date of the claimed invention would have found it obvious to recycle the transalkylation effluent stream of Sharp to the first separation zone, since Keim disclose that the residue which remains after working up of the transalkylation reaction product may be recycled to the isomerization and transalkylation process, optionally after having separated resinous material. The ordinary skilled artisan would have been motivated to recycle the transalkylation effluent stream to a first separation zone in order to separate the resinous material and decrease the occurrence of side reactions due the presence of the resinous material.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to VISHAL V VASISTH whose telephone number is (571)270-3716. The examiner can normally be reached M-F 9:00-4:30 and 7:00-10:00p.
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/VISHAL V VASISTH/Primary Examiner, Art Unit 1771