DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
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 final rejection. 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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 10 April 2026 has been entered.
Claim Status
Claims 1, 2, 4, 7, 11-13, 35-39, 41, and 43 are amended. Claims 3, 14, 16-18, 29, and 31 are cancelled. Claims 19-28 are withdrawn due to an earlier restriction requirement.
Claims 1, 2, 4-13, 15, 30, and 32-47 are pending for examination below.
Response to Arguments
Applicant’s arguments, see Remarks, filed 10 April 2026, with respect to the rejection(s) of claim(s) 1, 2, 4-13, 15, 30, and 32-47 under USC 103 have been fully considered and are persuasive. Specifically, Applicant’s argument that Xin does not teach the oxygen saturation tower is persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of newly discovered prior art in view of the amendments.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claim 44 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
With regard to claim 44, the claim recites “wherein performing the water dilution further comprises adding the recycle water to the oxygen.” However, claim 43 as amended recites that oxygen is saturated with water in an oxygen saturator tower. It is unclear if the water in the oxygen saturator tower is the recycle water, or if claim 44 is requiring a further step of adding recycle water to the oxygen separately from the step of saturating the oxygen with water in the saturator tower. Thus, the claim is indefinite.
For purposes of examination, the instant specification on pages 19-20 indicates that the recycled water from the acetic acid is recycled to both the ethane and the oxygen saturator towers (page 19, line 28-page 20, line 5). Thus, claim 44 will be interpreted as requiring that the recycle water is used as the water in the oxygen saturator tower. Appropriate correction is respectfully requested.
Claim Rejections - 35 USC § 103
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, 5, 6, 8, 10, 11, and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Yan et al. (CN 112142547, cited on IDS of 10/27/2023, machine translation provided herein) in view of Simanzhenkov et al. (US 2019/0135715) and Chhabra (Chapter 5: Applications in Humidification and Water Cooling).
With regard to claim 1, Yan teaches a method for ethane oxidative dehydrogenation (paragraph [0002]) comprising the following steps (See Figure 3 and Example 3 in corresponding paragraphs [0086]-[0091]):
a) mixing water in the form of water vapor 2, oxygen-containing gas 3, and ethane 1 to obtain a mixed feed (paragraphs [0086]-[0087]).
b) preheating the mixed feed in preheater 6’ (paragraph [0087]) which is a feed heat exchanger which exchanges heat with the effluent from the oxidative dehydrogenation reactor (Fig 3).
c) passing the heated mixed feed to the oxidative dehydrogenation reactor 8 comprising a catalyst to perform oxidative dehydrogenation (paragraph [0087]).
d) discharging a product gas 9 comprising ethylene, ethane, acetic acid, water, CO, and CO2 (paragraph [0087]).
Yan fails to teach i) that the water vapor is added to the ethane, ii) that water is added to the oxygen, iii) that the water is added to the ethane and oxygen in respective saturator towers, or iv) flowing only the saturated ethane through the heat exchanger before adding the saturated oxygen to the preheated saturated ethane.
With regard to adding water to the ethane i) and oxygen ii), Simanzhenkov teaches a process for oxidative dehydrogenation of ethane (paragraph [0001]). Simanzhenkov teaches that steam (water vapor) can be added to an individual reactant component such as ethane, oxygen, or a combination thereof, and then introduced into the ODH reactor (paragraph [0037]). Thus, Simanzhenkov teaches that it is known and equivalent to mix the water with each individual ethane and oxygen component separately as compared to mixing the water with the ethane and oxygen as in Yan.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to add the water to the ethane and oxygen separately, as claimed and as in Simanzhenkov, because each of Yan and Simanzhenkov teaches oxidative dehydrogenation of ethane in the presence of oxygen and water, Yan specifically teaches mixing ethane, oxygen, and water and adding the mixture to the ODH reactor, and Simanzhenkov teaches that mixing the water with the oxygen and ethane separately is known to be equivalently useful to mixing all together, and known equivalents are prima facie obvious, absent any evidence to the contrary.
With regard to the presence of ethane and oxygen saturator towers iii), Yan in view of Simanzhenkov teaches the method above where water vapor is added separately to the ethane and oxygen.
Simanzhenkov does not specifically teach that the water vapor is added in a saturator tower.
Chhabra teaches systems for humidification (saturation) of gas streams with water (page 471, Introduction). Chhabra teaches that the water is added to the gas in a packed column which increases the interfacial area in order to obtain a high rate of humidification (saturation) (page 494, section 5.5.1). While Chhabra does not use the term “saturator tower”, the instant specification recites that the saturator tower includes packing or column trays to provide contact stages for the transfer of water. Thus, one of ordinary skill in the art would recognize that the packed column of Chhabra functions as the claimed saturator tower.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the packed column (saturator tower) of Chhabra in the process of Yan in view of Simanzhenkov, because Simanzhenkov teaches adding water to the ethane and oxygen individually, where the ethane and oxygen are gas flows (paragraph [0037]), and Chhabra teaches that it is known to add water to gases in a packed column (saturator tower) which allows for obtaining high rates of humidification (saturation) (page 494, section 5.5.1).
With regard to the order of preheating iv), Simanzhenkov teaches a process for oxidative dehydrogenation of ethane (paragraph [0001]). Simanzhenkov teaches that water can be added to ethane, oxygen, or a combination thereof, and then the mixture of water and ethane is preheated to form the steam before entering the reactor with the other components (paragraph [0037]). Thus, Simanzhenkov contemplates that mixing all the components before heating as in Yan is equivalent to the claimed steps of saturating ethane, preheating, and then passing the saturated heated ethane to the reactor alongside saturated oxygen.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the preparation steps of Simanzhenkov in the process of Yan, because each of Yan and Simanzhenkov teach ethane oxidative dehydrogenation, Yan teaches mixing all the components together before preheating, and Simanzhenkov teaches that mixing water and ethane, preheating, and then adding oxygen to the preheated mixture is an equivalent preparation process which will produce the desired result of a mixed feed comprising ethane, steam, and oxygen, as claimed, without undue experimentation and with a reasonable expectation of success.
With regard to claims 5 and 6, Yan teaches adding the water vapor 2 to the ethane 1 in a conduit 4 upstream of the heat exchanger 6' (feed heat exchanger) which is a cross heat exchanger that utilizes the effluent as a heating medium (Fig. 3). Yan does not specifically teach heating the ethane and water mixture in a second heat exchanger upstream of the heat exchanger 6' (feed heat exchanger) (instant claim 6) and the ethane saturator tower (instant claim 5). However, this is merely a duplication of parts, where a second heat exchanger is present, which is prima facie obvious absent any evidence of criticality or unexpected results (see MPEP 2144.04(VI)(B)).
With regard to claim 8, Yan teaches adding water vapor 2 (steam) to a conduit 4 conveying the ethane. Yan does not explicitly teach that the steam comes from a steam drum. However, steam drums are commonly known in the art to be used to hold steam before use in processes where steam is used as a diluent. Thus, it would have been obvious to one of ordinary skill in the art at the time of the invention to use a steam drum to hold the steam of Yan before using it in the process.
With regard to claim 10, Yan in view of Simanzhenkov does not specifically teach adding water to ethane, preheating in a heat exchanger, then adding steam to ethane, and then further preheating in a heat exchanger. However, as water can be in the form of steam (see claim 8), then this is merely a duplication of parts, where steam is added to ethane, heated, and then further steam is added to ethane with further heating, which is prima facie obvious absent any evidence of criticality or unexpected results (see MPEP 2144.04(VI)(B)).
With regard to claim 11, Yan in view of Simanzhenkov and Chhabra teaches saturating oxygen with water as above, and Yan further teaches adding the oxygen stream 3 to a conduit 4 comprising the mixture of water and ethane (Fig. 3).
With regard to claim 13, Yan in view of Simanzhenkov teaches adding steam to the oxygen stream (Simanzhenkov paragraph [0037]). Yan in view of Simanzhenkov does not explicitly teach that the steam comes from a steam drum. However, steam drums are commonly known in the art to be used to hold steam before use in processes where steam is used as a diluent. Thus, it would have been obvious to one of ordinary skill in the art at the time of the invention to use a steam drum to hold the steam of Yan before using it in the process.
Claims 2, 15, 30-35, 37, 39, and 41 are rejected under 35 U.S.C. 103 as being unpatentable over Yan et al. (CN 112142547, cited on IDS of 10/27/2023, machine translation provided herein) in view of Simanzhenkov et al. (US 2019/0135715) and Chhabra (Chapter 5: Applications in Humidification and Water Cooling) as applied to claim 1 above, and further in view of Zellhuber et al. (US 2019/0382324).
With regard to claim 2, Yan in view of Simanzhenkov teaches the method above.
Yan in view of Simanzhenkov fails to teach recycling water from the effluent as the water added to the ethane feed.
Zellhuber teaches a method for oxidative dehydrogenation of ethane to ethylene and acetic acid (Abstract). Zellhuber further teaches separating water from acetic acid in an acetic acid recovery unit, and recycling the water to the preheating unit as the water or steam dilution stream for the oxidative dehydrogenation reactor (paragraphs [0057] and [0051]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to separate and recycle water from the effluent to the oxidative dehydrogenation process as the water in the feed, because Yan and Zellhuber each teach oxidative dehydrogenation of ethane to an effluent comprising ethylene, acetic acid, and water, and Zellhuber teaches separating and recycling the water as the dilution steam for the oxidative dehydrogenation reactor as an alternative to fresh water (paragraphs [0051], [0057]).
With regard to claim 15, Yan teaches the method above. Yan further teaches:
a) separating the product 9 in a gas-liquid separation tank 14 (flash drum) to produce a condensate 18 comprising most of the acetic acid and water and a process gas 15 comprising the remaining components of ethylene, ethane, CO, CO2, and a small amount of acetic acid and water (paragraphs [0035], [0088]).
b) passing the process gas 15 to an absorption tower 20 to remove the residual acetic acid and water from the process gas 15 (paragraphs [0035], [0088]).
c) discharging the liquid (paragraph [0035], [0088]).
Yan fails to teach utilizing the discharged stream as recycle water for the oxidative dehydrogenation reactor feed.
Zellhuber teaches a method for oxidative dehydrogenation of ethane to ethylene and acetic acid (Abstract). Zellhuber further teaches separating an acetic acid process water, separating the water from the acetic acid in an acetic acid recovery unit, and recycling the water to the preheating unit as the water or steam dilution stream for the oxidative dehydrogenation reactor (paragraphs [0057] and [0051]). Zellhuber further teaches that acetic acid is a desirable product that can be recovered (paragraph [0057]). Yan teaches the preheating unit is a heat exchanger with the effluent (Fig. 3).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to separate and recycle water from the effluent to the oxidative dehydrogenation process as the water in the feed passed to the preheating heat exchanger, because Yan and Zellhuber each teach oxidative dehydrogenation of ethane to an effluent comprising ethylene, acetic acid, and water, and separating acetic acid and water, and Zellhuber teaches separating and recycling the water as the dilution steam for the oxidative dehydrogenation reactor as an alternative to fresh water (paragraphs [0051], [0057]).
With regard to claims 30, 39, and 41, Yan in view of Simanzhenkov and Xin teaches the method above, where the recycled water and ethane are combined before adding the oxygen (Simanzhenkov paragraph [0037]). Yan further teaches:
a) passing the effluent from the process through the heat exchanger 6’ to recover heat by heating the feed and water mixture (instant claims 39 and 41).
b) discharging waste water comprising acetic acid from the process (paragraph [0088]).
Yan fails to teach recycling water from the discharged stream to the reactor as the water stream added to the ethane.
Zellhuber teaches a method for oxidative dehydrogenation of ethane to ethylene and acetic acid (Abstract). Zellhuber further teaches separating an acetic acid process water, separating the water from the acetic acid in an acetic acid recovery unit, and recycling the water to the preheating unit as the water or steam dilution stream for the oxidative dehydrogenation reactor (paragraphs [0057] and [0051]). Zellhuber further teaches that acetic acid is a desirable product that can be recovered (paragraph [0057]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to recycle water from the effluent to the oxidative dehydrogenation process as the water in the feed, because Yan and Zellhuber each teach oxidative dehydrogenation of ethane to an effluent comprising ethylene, acetic acid, and water, and separating acetic acid and water, and Zellhuber teaches separating and recycling the water as the dilution steam for the oxidative dehydrogenation reactor as an alternative to fresh water (paragraphs [0051], [0057]).
Yan in view of Zellhuber fails to explicitly teach that recovering the heat reduces energy consumption or that recovering the water reduces water consumption. However, one of ordinary skill in the art would expect these results from performing the recovering steps of Yan in view of Zellhuber, as these are well known results of heat recovery and water recovery in chemical processes, absent any evidence to the contrary.
With regard to claim 32, Yan teaches recovering the heat in the heat exchanger 6’ as above. Yan does not specifically teach heating the mixed feed in “another” heat exchanger to recover the heat. However, this is merely a duplication of parts, where a second heat exchanger is present and used in the same manner as the heat exchanger 6’, which is prima facie obvious absent any evidence of criticality or unexpected results (see MPEP 2144.04(VI)(B)).
With regard to claim 33, Yan further teaches:
a) separating the product 9 in a gas-liquid separation tank 14 (flash drum) to produce a condensate 18 comprising most of the acetic acid and water and a process gas 15 comprising the remaining components of ethylene, ethane, CO, and CO2 (paragraphs [0035], [0088]).
With regard to claim 34, Yan further teaches:
a) separating the product 9 in a gas-liquid separation tank 14 (flash drum) to produce a condensate 18 comprising most of the acetic acid and water and a process gas 15 comprising the remaining components of ethylene, ethane, CO, CO2, and a small amount of acetic acid and water (paragraphs [0035], [0088]).
b) passing the process gas 15 to an absorption tower 20 to remove the residual acetic acid and water from the process gas 15 by washing with a water absorbent (paragraphs [0035], [0088]).
c) discharging the liquid (paragraph [0035], [0088]).
Yan fails to teach i) recycling the water from the absorbent tower (scrubber) to the process as the feed water or ii) recovering the water from the condensate and using it as the absorbent water.
With regard to i), Zellhuber teaches a method for oxidative dehydrogenation of ethane to ethylene and acetic acid (Abstract). Zellhuber further teaches quenching the process gas with water, separating the water from the acetic acid in the quench water, and recycling the water to the preheating unit as the water or steam dilution stream for the oxidative dehydrogenation reactor (paragraphs [0056], [0057], and [0051]). Thus, Zellhuber teaches it is known to recycle the water from the acetic acid scrubber (quench) as the feed water.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to recycle water from the quench bottoms (scrubber bottoms) to the oxidative dehydrogenation process as the water in the feed, because Yan and Zellhuber each teach oxidative dehydrogenation of ethane to an effluent comprising ethylene, acetic acid, and water, and separating acetic acid and water, and Zellhuber teaches separating and recycling the water as the dilution steam for the oxidative dehydrogenation reactor as an alternative to fresh water (paragraphs [0051], [0057]).
With regard to ii), while Yan and Zellhuber do not explicitly teach using the water from the effluent as the absorbent or scrubber water, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the water separated from the effluent as taught by Zellhuber as the absorbent water in Yan, because Yan teaches using water as the absorbent and Zellhuber teaches that separating water from acetic acid in the effluent is known and using the water is useful in place of freshwater (paragraphs [0056]-[0057]).
With regard to claims 35 and 37, Yan in view of Simanzhenkov and Zellhuber teaches the method of claim 30 above, where water vapor (water of instant claim 35, steam of instant claim 37) is added to the ethane upstream of adding the oxygen (Simanzhenkov), and wherein the recycle water is used to form the dilution steam (Zellhuber paragraph (paragraphs [0051], [0057]).
With regard to claim 36, Yan in view of Simanzhenkov, Xin, and Zellhuber teaches the method of claim 30 above, where water vapor (steam) is added to the ethane in the ethane saturator tower (Xin Abstract), and wherein the recycle water is used to form the dilution steam (Zellhuber paragraph (paragraphs [0051], [0057]).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Yan et al. (CN 112142547, cited on IDS of 10/27/2023, machine translation provided herein) in view of Simanzhenkov et al. (US 2019/0135715) and Chhabra (Chapter 5: Applications in Humidification and Water Cooling) as applied to claim 1 above, and further in view of Zander et al. (US 2016/0207035).
With regard to claim 4, Yan in view of Simanzhenkov and Chhabra teaches the method above, where the water is added to the ethane in a packed column (saturator tower).
Yan in view of Simanzhenkov and Chhabra fails to teach heating the water in a heat exchanger with the effluent before adding the water to the ethane.
Zander teaches a method for oxidative dehydrogenation of ethane (paragraph [0104]). Zander further teaches that the system comprises preheating water in heat exchanger 9 before mixing with ethane in a conduit, followed by sending the mixture to heat exchanger 12 and then to reactor 1, where heat exchanger 9 exchanges effluent heat with the water (Figure 3, paragraph [0079]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to heat the water before adding the water to the ethane and preheating, because Yan in view of Simanzhenkov and Xin teaches adding water to the ethane before preheating, and Zander teaches it is known and suitable cool the effluent by preheating water before further mixing the water with the ethane and further preheating (Figure 3, paragraph [0079]).
Claims 7, 9, and 12 are rejected under 35 U.S.C. 103 as being unpatentable over Yan et al. (CN 112142547, cited on IDS of 10/27/2023, machine translation provided herein) in view of Simanzhenkov et al. (US 2019/0135715) and Chhabra (Chapter 5: Applications in Humidification and Water Cooling) as applied to claims 6, 8, and 11 above, and further in view of Zander et al. (US 2016/0207035).
With regard to claim 7, Yan in view of Simanzhenkov and Xin teaches the method of claim 6 above, where the water is added to the ethane in a conduit (Fig. 3).
Yan in view of Simanzhenkov and Xin fails to teach heating the water in a heat exchanger with the effluent before adding the water to the ethane.
Zander teaches a method for oxidative dehydrogenation of ethane (paragraph [0104]). Zander further teaches that the system comprises preheating water in heat exchanger 9 before mixing with ethane in a conduit, and sending the mixture to heat exchanger 12 before reactor 1, where heat exchanger 9 exchanges effluent heat with the water (Figure 3, paragraph [0079]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to heat the water before adding the water to the ethane and preheating, because Yan in view of Simanzhenkov teaches adding water to the ethane before preheating, and Zander teaches it is known and suitable cool the effluent by preheating water before further use of the water in the oxidative dehydrogenation process (Figure 3, paragraph [0079]).
With regard to claim 9, Yan in view of Simanzhenkov and Xin teaches the method of claim 8 above, where the steam is added to the ethane in a conduit.
Yan in view of Simanzhenkov and fails to teach heating the water in a heat exchanger with the effluent before adding the water to the steam drum.
Zander teaches a method for oxidative dehydrogenation of ethane (paragraph [0104]). Zander further teaches that the system comprises preheating water in heat exchanger 9, where heat exchanger 9 exchanges effluent heat with the water (Figure 3, paragraph [0079]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to heat the water before passing to the steam drum before further use of the steam, because Yan in view of Simanzhenkov teaches adding preheating the water alone before further use as steam, and Zander teaches it is known and suitable cool the effluent by preheating water before further use of the water (Figure 3, paragraph [0079]).
With regard to claim 12, Yan in view of Simanzhenkov and Xin teaches adding water to oxygen before (upstream) adding the ethane stream and sending to the reactor as in claim 11.
Yan in view of Simanzhenkov and Xin fails to teach heating the water and oxygen in a heat exchanger with the effluent before adding the water and oxygen to the ethane.
Zander teaches a method for oxidative dehydrogenation of ethane (paragraph [0104]). Zander further teaches that the system comprises preheating water in heat exchanger 9 before mixing with ethane in a conduit, and sending the mixture to heat exchanger 12 before reactor 1, where heat exchanger 9 exchanges effluent heat with the water (Figure 3, paragraph [0079]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to heat the water and oxygen mixture of Yan in view of Simanzhenkov before adding the water and oxygen mixture to the ethane, because Yan in view of Simanzhenkov teaches adding water to the oxygen before mixing with the ethane and preheating, and Zander teaches it is known and suitable cool the effluent by preheating water before further use of the water (Figure 3, paragraph [0079]).
Claim 38 is rejected under 35 U.S.C. 103 as being unpatentable over Yan et al. (CN 112142547, cited on IDS of 10/27/2023, machine translation provided herein) in view of Simanzhenkov et al. (US 2019/0135715), Chhabra (Chapter 5: Applications in Humidification and Water Cooling), and Zellhuber et al. (US 2019/0382324) as applied to claim 30 above, and further in view of Rogers (US 4,021,500).
With regard to claim 38, Yan in view of Simanzhenkov and Zellhuber teaches the method of claim 30 above, wherein the recycle water is used to form the dilution steam (Zellhuber paragraph (paragraphs [0051], [0057])..
Yan in view of Simanzhenkov and Zellhuber fails to teach vaporizing the recycle water in a steam dilution drum to give the dilution steam.
Rogers teaches a method of oxidative dehydrogenation of hydrocarbons (column 1, lines 1-5), separating water from the effluent of the dehydrogenation reactor, and passing it to the steam generator which vaporizes the water, and then passing it to the steam drum, where the steam from the steam drum is used as dilution steam in the process (column 1, line 40-column 2, line 6). Roger further teaches that recycling the water as steam removes the need to dispose of the separated water, which is expensive in time and labor (column 1, lines 9-15).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to pass the recycled water stream of Zellhuber to a steam drum before recycling as in Rogers, because each of Zellhuber and Rogers teaches recycling water to the oxidative dehydrogenation process, and Rogers teaches that forming the water into steam which is used in the process removes the need to dispose of the separated water, which is expensive in time and labor (column 1, lines 9-15).
Claims 40 and 42 are rejected under 35 U.S.C. 103 as being unpatentable over Yan et al. (CN 112142547, cited on IDS of 10/27/2023, machine translation provided herein) in view of Simanzhenkov et al. (US 2019/0135715), Chhabra (Chapter 5: Applications in Humidification and Water Cooling), and Zellhuber et al. (US 2019/0382324) as applied to claim 39 above, and further in view of Zander et al. (US 2016/0207035).
With regard to claim 40, Yan in view of Simanzhenkov and Zellhuber teaches the method of claim 39 above, where the recycle water is added to the ethane.
Yan in view of Simanzhenkov fails to teach heating the recycle water in a heat exchanger with the effluent before adding the water to the ethane.
Zander teaches a method for oxidative dehydrogenation of ethane (paragraph [0104]). Zander further teaches that the system comprises preheating water in heat exchanger 9 before mixing with ethane in a conduit, and sending the mixture to heat exchanger 12 before reactor 1, where heat exchanger 9 exchanges effluent heat with the water (Figure 3, paragraph [0079]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to heat the water before adding the water to the ethane and preheating, because Yan in view of Simanzhenkov teaches adding water to the ethane before preheating, and Zander teaches it is known and suitable cool the effluent by preheating water before further use of the water (Figure 3, paragraph [0079]).
With regard to claim 42, Yan in view of Simanzhenkov teaches adding water to oxygen before adding the ethane stream and sending to the reactor (Simanzhenkov paragraph [0037].
Yan in view of Simanzhenkov fails to teach heating the water and oxygen in a heat exchanger with the effluent before adding the water to the ethane.
Zander teaches a method for oxidative dehydrogenation of ethane (paragraph [0104]). Zander further teaches that the system comprises preheating water in heat exchanger 9 before mixing with ethane in a conduit, and sending the mixture to heat exchanger 12 before reactor 1, where heat exchanger 9 exchanges effluent heat with the water (Figure 3, paragraph [0079]).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to heat the water and oxygen mixture of Yan in view of Simanzhenkov before adding the water and oxygen mixture to the ethane and preheating, because Yan in view of Simanzhenkov teaches adding water to the oxygen before mixing with the ethane and preheating, and Zander teaches it is known and suitable cool the effluent by preheating water before further use of the water (Figure 3, paragraph [0079]).
Claims 43-47 are rejected under 35 U.S.C. 103 as being unpatentable over Yan et al. (CN 112142547, cited on IDS of 10/27/2023, machine translation provided herein) in view of Simanzhenkov et al. (US 2019/0135715), Chhabra (Chapter 5: Applications in Humidification and Water Cooling), and Zellhuber et al. (US 2019/0382324).
With regard to claims 43 and 44, Yan teaches a method for ethane oxidative dehydrogenation (paragraph [0002]) comprising the following steps (See Figure 3 and Example 3 in corresponding paragraphs [0086]-[0091]):
a) mixing water in the form of water vapor 2, oxygen-containing gas 3, and ethane 1 to obtain a mixed feed (paragraphs [0086]-[0087]).
b) preheating the mixed feed in preheater 6’ (paragraph [0087]) which is a feed heat exchanger which exchanges heat with the effluent from the oxidative dehydrogenation reactor (Fig 3).
c) passing the heated mixed feed to the oxidative dehydrogenation reactor 8 comprising a catalyst to perform oxidative dehydrogenation (paragraph [0087]).
d) discharging a product gas 9 comprising ethylene, ethane, acetic acid, water, CO, and CO2 (paragraph [0087]).
Yan fails to teach i) that the water vapor is added to the ethane, ii) that water is added to the oxygen, iii) that the water is added to the ethane and oxygen in respective saturator towers, or iv) recycling water from the discharged stream as the dilution water.
With regard to adding water to the ethane i) and oxygen ii), Simanzhenkov teaches a process for oxidative dehydrogenation of ethane (paragraph [0001]). Simanzhenkov teaches that steam (water vapor) can be added to an individual reactant component such as ethane, oxygen, or a combination thereof, and then introduced into the ODH reactor (paragraph [0037]). Thus, Simanzhenkov teaches that it is known and equivalent to mix the water with each individual ethane and oxygen component separately as compared to mixing the water with the ethane and oxygen as in Yan.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to add the water to the ethane and oxygen separately, as claimed and as in Simanzhenkov, because each of Yan and Simanzhenkov teaches oxidative dehydrogenation of ethane in the presence of oxygen and water, Yan specifically teaches mixing ethane, oxygen, and water and adding the mixture to the ODH reactor, and Simanzhenkov teaches that mixing the water with the oxygen and ethane separately is known to be equivalently useful to mixing all together, and known equivalents are prima facie obvious, absent any evidence to the contrary.
With regard to the presence of ethane and oxygen saturator towers iii), Yan in view of Simanzhenkov teaches the method above where water vapor is added separately to the ethane and oxygen.
Simanzhenkov does not specifically teach that the water vapor is added in a saturator tower.
Chhabra teaches systems for humidification (saturation) of gas streams with water (page 471, Introduction). Chhabra teaches that the water is added to the gas in a packed column which increases the interfacial area in order to obtain a high rate of humidification (saturation) (page 494, section 5.5.1). While Chhabra does not use the term “saturator tower”, the instant specification recites that the saturator tower includes packing or column trays to provide contact stages for the transfer of water. Thus, one of ordinary skill in the art would recognize that the packed column of Chhabra functions as the claimed saturator tower.
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to use the packed column (saturator tower) of Chhabra in the process of Yan in view of Simanzhenkov, because Simanzhenkov teaches adding water to the ethane and oxygen individually, where the ethane and oxygen are gas flows (paragraph [0037]), and Chhabra teaches that it is known to add water to gases in a packed column (saturator tower) which allows for obtaining high rates of humidification (saturation) (page 494, section 5.5.1).
With regard to the recycled water iv), Zellhuber teaches a method for oxidative dehydrogenation of ethane to ethylene and acetic acid (Abstract). Zellhuber further teaches separating an acetic acid process water, separating the water from the acetic acid in an acetic acid recovery unit, and recycling the water to the preheating unit as the water or steam dilution stream for the oxidative dehydrogenation reactor (paragraphs [0057] and [0051]). Zellhuber further teaches that acetic acid is a desirable product that can be recovered (paragraph [0057]). Yan teaches the preheating unit is a heat exchanger with the effluent (Fig. 3).
Therefore, it would have been obvious to one of ordinary skill in the art at the time of the invention to separate and recycle water from the effluent to the oxidative dehydrogenation process as the water in the feed passed to the preheating heat exchanger, because Yan and Zellhuber each teach oxidative dehydrogenation of ethane to an effluent comprising ethylene, acetic acid, and water, and separating acetic acid and water, and Zellhuber teaches separating and recycling the water as the dilution steam for the oxidative dehydrogenation reactor as an alternative to fresh water (paragraphs [0051], [0057]).
With regard to claims 45-47, Yan in view of Zellhuber teaches heating the ethane and recycle water mixture in heat exchanger 6’ against the effluent from the dehydrogenation reactor (paragraph [0087] and Fig. 3). This is equivalent to recovering heat from the effluent by heat exchange of the recycle water and ethane mixture of instant claims 45-47.
Conclusion
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/Alyssa L Cepluch/Examiner, Art Unit 1772
/Renee Robinson/Primary Examiner, Art Unit 1772
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