DETAILED ACTION
Status of Claims
This is a non-final office action on the merits in response to the arguments and/or amendments filed on 3 June 2026 and the request for continued examination filed on 3 June 2026.
Claim(s) 35 and 36 is/are canceled. Claim(s) 16, 18, 33, and 45 is/are amended. Claim(s) 47 and 48 is/are new.
Claim(s) 1, 2, 9, 10, 12, 14, 16, 18, 19, 26, 27, 29, 31, 33, 37, 38, and 45-48 is/are currently pending and have been examined.
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 .
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 3 June 2026 has been entered.
Claim Rejections - 35 USC § 112(a)
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 45-48 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for applications subject to pre-AIA 35 U.S.C. 112, the inventor(s), at the time the application was filed, had possession of the claimed invention.
Amended claim 45 recites the non-original limitation: “each of the plurality of orifices have a diameter of from about 1.5 mm to about 2 mm”. This limitation appears to have first entered the claims in the amendments filed 18 April 2025. In association with those amendments, applicant identified [0038], [0059], Example 4, and Figs. 8(a)-(g) of the published application as support for the amendments at large. Of these, only [0038] appears relevant to the identified limitation.
[0038] In one embodiment the orifices of the sparging device can have a size of from about 1.5 mm to about 5 mm in diameter, preferably from about 2 mm (approximately 5/64 inch) to about 5 mm in diameter. In another embodiment, the orifices of the sparging device can be spaced from about 10 cm to about 20 cm (about 4 to about 8 inches) apart from one another.
This disclosure describes a range for the orifices of 1.5mm to 5mm and a preferable range for the orifices of 2mm to 5mm, but does not disclose, describe, or suggest a range for the orifices of from 1.5mm to 2mm. As such, one of ordinary skill in the art would not consider this disclosure to support the identified limitation. The remainder of the originally filed disclosure similarly fails to support the identified limitation.
Because the claimed invention includes a non-original limitation which is not supported by the originally filed disclosure, one of ordinary skill in the art would not recognize applicant as possessing the claimed invention at the time of filing. Therefore the claim is rejected based on the written description requirement. Claims 46, 47, and 48 are similarly rejected.
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.
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, 2, 9, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1).
Regarding Claim 1: Barnes discloses a process for removing hydrogen sulfide from sour water, comprising:
obtaining sour water; adjusting the pH of the sour water to a pH of from 4 to 5 by addition of a first acid to form acidified sour water (Relating to sour water treatment, still with reference to FIG. 1, an acidic chemical is introduced by acidic chemical inlet feed 114 to be mixed with the predominately aqueous sour stream 110 in a first sour water treatment step in an acidic chemical mixing apparatus 112. See at least [0043]. Also: The pH of the resulting aqueous solution discharge stream 116 may be less than approximately a pH of 4 to promote the formation of approximately 99.9% of total sulfide by molar equivalent into the hydrogen sulfide species, in accordance with FIG. 2A. In some embodiments, a pH greater or less than 4 may be desirable and may be calculated by one skilled in the art such that a desired fraction of the total combined concentration of the target acid-gas exists as the conjugate base species in the resulting aqueous solution discharge stream 116. See at least [044]).
sparging the acidified sour water with a first hydrocarbon gas in a first vessel to produce a first sour gas and a sweetened water, wherein said sparging is conducted via a first sparging device disposed at or proximal to a base of the first vessel (stripping gas stream 124 is introduced to the resulting aqueous solution discharge stream 116 inside a gas-water contactor vessel 118. See at least [0046]. Also: the stripping gas is anoxic, or substantially without oxygen, being for example nitrogen, methane, natural gas. See at least [0053]. Also: the gas-water contactor vessel 118 may be a horizontal tank with an internal sparge bar for injecting the stripping gas stream 124. See at least [0048]. Also: The substantially sweet natural gas used in sour water stripping in stripping gas stream 124 enters the gas-water contactor vessel 118 at an inlet feed point located near the bottom of the vessel such that the gas has substantial contact time with the liquid in the vessel to induce sour gas stripping. See at least [0063]).
and separating the first sour gas from the sweetened water (a substantially sweetened aqueous product stream 128 discharged from the gas-water contactor vessel 118. See at least [0066]).
wherein: the pH of the acidified sour water in the first vessel is in a range of from 4 to 5 during the process; and the process is conducted as a batch process (a pH greater or less than 4 may be desirable and may be calculated by one skilled in the art such that a desired fraction of the total combined concentration of the target acid-gas exists as the conjugate base species in the resulting aqueous solution discharge stream 116. See at least [044]. Also: the disclosed system and method may be implemented in a batch treatment scheme. See at least [0079]) and does not use stripping towers (the gas-water contactor vessel 118 may be a horizontal tank with an internal sparge bar for injecting the stripping gas stream 124. See at least [0048]).
Barnes does not expressly disclose wherein the pH of the acidified sour water in the first vessel is maintained substantially constant during the process.
However, Mueller teaches wherein the pH of the acidified sour water in the vessel is maintained substantially constant during the process (process fluid is flowed at 243 from any of a number of possible sources … into a degassing compartment 213, wherein the amount of entrained and dissolved gases, such as hydrogen sulfide, in the process fluid may be reduced. In one embodiment, the degassing compartment 213 comprises a pH analyzer 218a that monitors the pH of the process fluid in the degassing compartment 213. See at least [0057]. Also: pH analyzer 218a monitors the pH of the process fluid. The pH of the process fluid may be measured by any method known in the art, and is not limited herein. If the process fluid has a pH greater than 4, then acid may be added, shown at 222, to the process fluid until a pH of less than 4 is reached. In one embodiment, the pH of the process fluid is maintained between 3.0 and 3.5. In one embodiment, the acid added to the process fluid to maintain the pH may be citric acid. See at least [0058]).
Barnes provides a system that removes a desired fraction of hydrogen sulfide from sour water by lowering the pH of the water to a level somewhat greater than 4, upon which the claimed invention’s maintenance of the pH of the water at a constant level can be seen as an improvement. However, Mueller demonstrates that the prior art already knew of maintaining the pH of a liquid from which hydrogen sulfide is to be removed. One of ordinary skill in the art could have trivially applied the techniques of Mueller to the system of Barnes by maintaining the chosen pH of Barnes in the contacting vessel. Further, one of ordinary skill in the art would have recognized that such an application of Mueller would have resulted in an improved system which, by maintaining a constant pH, would maintain a constant fraction of hydrogen sulfide in its liquid discharge stream. As such, the application of Mueller and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller.
Regarding Claim 2: Barnes in view of Mueller makes obvious the above limitations. Additionally, Barnes discloses one or more of the following characteristics: (a) the first acid comprises hydrochloric acid, acetic acid, or a combination thereof ([0043]); (b) the first acid is hydrochloric acid ([0043]); (c) the first hydrocarbon gas is sweet gas ([0053]); (d) the pH is maintained substantially constant during the process; (e) the process is conducted in an oxygen-free environment; and (f) the process further comprises heating the first vessel during the process
Regarding Claim 9: Barnes in view of Mueller makes obvious the above limitations. Additionally, Barnes discloses wherein the first sparging device comprises at least one sparging finger fluidly connected to a source of the first hydrocarbon gas and disposed horizontally within the first vessel, wherein the sparging finger comprises a pipe with a plurality of orifices for releasing the first hydrocarbon gas into the first vessel (the gas-water contactor vessel 118 may be a horizontal tank with an internal sparge bar for injecting the stripping gas stream 124. See at least [0048]. Also: The substantially sweet natural gas used in sour water stripping in stripping gas stream 124 enters the gas-water contactor vessel 118 at an inlet feed point located near the bottom of the vessel such that the gas has substantial contact time with the liquid in the vessel to induce sour gas stripping. See at least [0063]).
Regarding Claim 16: Barnes in view of Mueller makes obvious the above limitations. Additionally, Barnes discloses incinerating the first sour gas following the step of separating the first sour gas from the sweetened water (sour stripping gas stream 662 was instead transferred to a flare stack where both methane and the hydrogen sulfide vapors stripped from reduced pH aqueous mixture stream 616 in sour water stripper 660 were combusted and burned in the presence of oxygen. See at least [0109]); sending the first sour gas to a vapor recovery unit to be sweetened and recycled to the process following the step of separating the first sour gas from the sweetened water (process unit for sour gas treatment 122 may be designed by one skilled in the art to sufficiently remove sour components from a gas stream. See at least [0058]. Also: process unit for sour gas treatment 122 is used to generate a stream of substantially sweet gas, such as stripping gas stream 124, that may be further used in a gas stripping step in a concurrent water treatment process. See at least [0059]); or sending the sweetened water to a storage tank following the step of separating the first sour gas from the sweetened water.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1), and further in view of Myszczyszyn (WO2015154168 A1).
Regarding Claim 10: Barnes in view of Mueller makes obvious the above limitations. However, Barnes does not disclose one or more of the following characteristics: (a) a plurality of orifices are evenly spaced apart from one another; and (b) the first sparging device comprising a plurality of sparging fingers. However, Myszczyszyn teaches (a) a plurality of orifices are evenly spaced apart from one another (Tn one embodiment according to the present invention, the apertures were located 12 inches apart on ¼ inch stainless steel tubing and had a diameter of 1/8 inch. See at least second paragraph of page 5); and (b) the first sparging device comprising a plurality of sparging fingers (See at least Fig. 4).
Barnes and Mueller suggest a hydrogen sulfide stripping unit which uses a sparge bar to introduce the stripping gas into the liquid, which differs from the claimed invention by the substitution of Barnes’s sparge bar with a more specific sparging system using regularly placed gas outlets or multiple gas lines. Myszczyszyn demonstrates that the prior art already knew of sparging systems which use regularly placed gas outlets or multiple gas lines to remove hydrogen sulfide. One of ordinary skill in the art could have easily substituted the bubbler of Myszczyszyn into the system of Barnes and Mueller. Further, one of ordinary skill in the art would have recognized that such a substitution would have predictably resulted in a simpler and lower cost method of introducing gas into the liquid (Myszczyszyn, Paragraph 6 of Page 4). As such, the identified substitution and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller and Myszczyszyn.
Claims 12 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1), and further in view of Mante et al. (US 2019/0300405 A1).
Regarding Claim 12: Barnes in view of Mueller makes obvious the above limitations. Barnes does not disclose removing a portion of the sour water from the first vessel; mixing, externally to the first vessel, the portion of the sour water from the first vessel together with a second portion of the first hydrocarbon gas to form a first mixture; and providing the first mixture to the first vessel.
However, Mante teaches removing a portion of a liquid from a first vessel, optionally via an outlet disposed at the base of the first vessel; mixing externally to the first vessel, the portion of the liquid from the first vessel together with a portion of a gas to form a first mixture; and providing the first mixture to the first vessel; optionally, wherein said mixing is carried out using a first static mixer (Dissolution column 102 contains a body of acidic pressurized liquid 110 and a gas headspace 112 above the body of acidic pressurized liquid at an over pressure. … Dissolution column 102 also comprises a recirculation liquid outlet 116 and a fluid feed inlet 118 in the bottom, which constitute the fluid recirculation loop 103. … The recirculation liquid outlet 116 provides a small portion of the acidic pressurized water to the recirculation pump 128 and the pressure of the small portion of the acidic pressurized water is elevated larger than the pressure of the acidic pressurized water in dissolution column 102. A gas and liquid mixture of O.sub.2/O.sub.3 produced by an ozone generator 124 is then mixed with the small portion of the acidic pressurized water to form a mixture of O.sub.2/O.sub.3 gas and acidic pressurized water that has gaseous and liquid phases and has a pressure greater than the pressure of the acidic pressurized water in dissolution column 102. As a result, the mixture of O.sub.2/O.sub.3 gas and acidic pressurized water flows into dissolution column 102 at the fluid feed inlet 118 through action of fluid recirculation loop 103, where the O.sub.2/O.sub.3 gas and liquid mixture is fed into dissolution column 102 by passing through fluid diffuser device 114 that is fluidly connected to fluid feed inlet 118. See at least [0403]. Also: The mixing unit 2 comprises of multiple specially designed injection nozzles and a static mixer. See at least [0394]).
Barnes and Mueller suggest a hydrogen sulfide stripping unit, upon which the claimed invention’s use of a recirculation mixing system can be seen as an improvement. However, Mante demonstrates that the prior art already knew of using a recirculation loop to inject gas and mix that gas with a liquid. One of ordinary skill in the art could have easily applied the techniques of Mante to the stripping unit of Barnes and Mueller. Further, one of ordinary skill in the art would have recognized that such an application of Mante would have resulted in superior mixing for Barnes’ stripper and thus better stripping performance. As such, the identified application of Mante and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller and Mante.
Regarding Claim 14: Barnes in view of Mueller and Mante makes obvious the above limitations. Additionally, Mante teaches wherein said steps of removing the portion of the liquid from the first vessel; mixing externally to the first vessel, the second portion of the liquid from the first vessel together with the first portion of the gas to form the first mixture; and providing the first mixture to the first vessel are performed continuously during the process (the operation of system 100a generates a continuous liquid stream. See at least [0425]). The motivation to combine Barnes, Mueller, and Mante is the same as explained under claim 12 above, and is incorporated herein.
Claims 18, 19, 26, 33, 37, and 38 are rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1), and further in view of DeFosse et al. (US 2011/0272365 A1).
Regarding Claim 18: Barnes in view of Mueller makes obvious the above limitations. As previously noted above, Barnes discloses providing water to a vessel; a pH of from 4 to 5 by addition of a acid to the water, as needed; sparging the acidified water in the vessel with a hydrocarbon gas to produce a sour gas and a sweetened water, wherein said sparging is conducted via a sparging device disposed at or proximal to a base of the vessel; and separating the sour gas from the sweetened water;. As previously noted, Mueller teaches wherein the pH acidified sour water is maintained substantially constant during the process. Barnes does not expressly disclose performing these unit operations a subsequent time.
However, DeFosse teaches providing the sweetened water formed in a first vessel to second vessel, the pH of the sweetened water at a pH by addition of a second acid to the sweetened water, as needed; mixing the acidified sweetened water with a second hydrocarbon gas to produce a second sour gas and a further sweetened water; and separating the second sour gas from the further sweetened water (See Fig. 1. Also: The water from the first separator 20A, while containing less hydrogen sulfide than the sour water being input into the system 100, can still contain some hydrogen sulfide dissolved in the water. This remaining water can be routed to a subsequent stage with a second mixer 10B and a second separator 20B to remove some of the hydrogen sulfide remaining in the water. See at least [0023]. Also: In one aspect, a pH adjustment module 6B can be used to lower the pH of the water before it is routed to the second mixer 10B. See at least [0024]. Also: The second mixer 10B can be used to mix water from the first separator 20A with stripper gas from the stripper gas feed inlet 4 and then the mixture can be routed to the second separator 20B to separate another gas portion from the water. See at least [0025]).
Barnes and Mueller suggest a contactor system which strips hydrogen sulfide from a sour water stream to produce sweetened water, upon which the claimed invention’s repetition of this process can be seen as an improvement. However, DeFosse demonstrates that the prior art already knew of repeating the process of stripping hydrogen sulfide from a sour water stream. One of ordinary skill in the art could have trivially applied DeFosse’s repetition of the process with the contactor system equipment of Barnes and Mueller. Further, one of ordinary skill in the art would have recognized that such an application of DeFosse would have resulted in an improved system which would produce a water stream with a reduced amount of hydrogen sulfide relative to the base techniques of Barnes and Mueller. As such, the identified application of DeFosse and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller and DeFosse.
Regarding Claim 19: Barnes in view of Mueller and DeFosse makes obvious the above limitations. As previously noted, Barnes discloses one or more of the following characteristics: (a) the acid comprises hydrochloric acid, acetic acid, or a combination thereof ([0043]); (b) the acid is hydrochloric acid ([0043]); (c) the hydrocarbon gas is sweet gas ([0053]); (d) the pH is maintained substantially constant during the process; (e) the process is conducted in an oxygen-free environment; and (f) the process further comprises heating the vessel during the process. The motivation to combine Barnes, Mueller, and DeFosse is the same as explained under claim 18 above, and is incorporated herein.
Regarding Claim 26: Barnes in view of Mueller and DeFosse makes obvious the above limitations. As previously noted, Barnes discloses wherein the sparging device comprises at least one sparging finger fluidly connected to a source of the hydrocarbon gas and disposed horizontally within the vessel, wherein the at least one sparging finger comprises a pipe with a plurality of orifices for releasing the hydrocarbon gas into the vessel (the gas-water contactor vessel 118 may be a horizontal tank with an internal sparge bar for injecting the stripping gas stream 124. See at least [0048]. Also: The substantially sweet natural gas used in sour water stripping in stripping gas stream 124 enters the gas-water contactor vessel 118 at an inlet feed point located near the bottom of the vessel such that the gas has substantial contact time with the liquid in the vessel to induce sour gas stripping. See at least [0063]). The motivation to combine Barnes, Mueller, and DeFosse is the same as explained under claim 18 above, and is incorporated herein.
Regarding Claim 33: Barnes in view of Mueller and DeFosse makes obvious the above limitations. As previously noted, Barnes discloses incinerating the sour gas following the step of separating the sour gas from the sweetened water (sour stripping gas stream 662 was instead transferred to a flare stack where both methane and the hydrogen sulfide vapors stripped from reduced pH aqueous mixture stream 616 in sour water stripper 660 were combusted and burned in the presence of oxygen. See at least [0109]); sending the sour gas to a vapor recovery unit to be sweetened and recycled to the process following the step of separating the sour gas from the sweetened water (process unit for sour gas treatment 122 may be designed by one skilled in the art to sufficiently remove sour components from a gas stream. See at least [0058]. Also: process unit for sour gas treatment 122 is used to generate a stream of substantially sweet gas, such as stripping gas stream 124, that may be further used in a gas stripping step in a concurrent water treatment process. See at least [0059]); or sending the sweetened water to a storage tank following the step of separating the second sour gas from the sweetened water. The motivation to combine Barnes, Mueller, and DeFosse is the same as explained under claim 18 above, and is incorporated herein.
Regarding Claim 37: Barnes in view of Mueller and DeFosse makes obvious the above limitations. Additionally, DeFosse teaches providing the further sweetened water formed in the second vessel to a third vessel for further sweeting of the water (The water from the second separator can be routed through a last stage containing a third mixer 10C and a third separator 20C. See at least [0026]. Also: From the third separator 20C, remaining water can be used to form the final water product containing significantly reduced levels of hydrogen sulfide (sweet water) in relation to the sour water that was input into the system 100. See at least [0028]). The motivation to combine Barnes, Mueller, and DeFosse is the same as explained under claim 18 above, and is incorporated herein.
Regarding Claim 38: Barnes in view of Mueller and DeFosse makes obvious the above limitations. Additionally, DeFosse teaches one or more of the following characteristics: (a) the first acid and the second acid are the same acid (In one embodiment, the pH of the sour water is lowered by the addition of an acid, for example, hydrochloric acid. See at least [0008], [0013], and Fig. 1), (b) the first acid and the second acid are hydrochloric acid (In one embodiment, the pH of the sour water is lowered by the addition of an acid, for example, hydrochloric acid. See at least [0008], [0013], and Fig. 1), (c) the first hydrocarbon gas and the second hydrocarbon gas are the same gas (See Fig. 1. Also: A stripper gas can be provided via stripper gas feed inlet 4 for supplying a stripper gas that will be mixed with the sour water. The stripper gas can be methane, CO.sub.2, a mixture of methane and CO.sub.2, steam, nitrogen, a mixture of any of these gases, etc. See at least [0015]); (d) the first hydrocarbon gas and the second hydrocarbon gas are sweet gas (See Fig. 1. Also: A stripper gas can be provided via stripper gas feed inlet 4 for supplying a stripper gas that will be mixed with the sour water. The stripper gas can be methane, CO.sub.2, a mixture of methane and CO.sub.2, steam, nitrogen, a mixture of any of these gases, etc. See at least [0015]). The motivation to combine Barnes, Mueller, and DeFosse is the same as explained under claim 18 above, and is incorporated herein.
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1), and further in view of DeFosse et al. (US 2011/0272365 A1), and further in view of Myszczyszyn (WO2015154168 A1).
Regarding Claim 27: Barnes in view of Mueller and DeFosse makes obvious the above limitations. However, Barnes does not disclose one or more of the following characteristics: (a) a plurality of orifices are evenly spaced apart from one another; and (b) the second sparging device comprising a plurality of sparging fingers. However, Myszczyszyn teaches (a) a plurality of orifices are evenly spaced apart from one another (Tn one embodiment according to the present invention, the apertures were located 12 inches apart on ¼ inch stainless steel tubing and had a diameter of 1/8 inch. See at least second paragraph of page 5); and (b) the sparging device comprising a plurality of sparging fingers (See at least Fig. 4).
Barnes, Mueller, and DeFosse suggest sequential hydrogen sulfide stripping units which use sparge bars to introduce the stripping gas into the liquid, which differs from the claimed invention by the substitution of Barnes’s sparge bars with a more specific sparging system using regularly placed gas outlets or multiple gas lines. Myszczyszyn demonstrates that the prior art already knew of sparging systems which use regularly placed gas outlets or multiple gas lines to remove hydrogen sulfide. One of ordinary skill in the art could have easily substituted the bubbler of Myszczyszyn into the system of Barnes, Mueller, and DeFosse. Further, one of ordinary skill in the art would have recognized that such a substitution would have predictably resulted in a simpler and lower cost method of introducing gas into the liquid (Myszczyszyn, Paragraph 6 of Page 4). As such, the identified substitution and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller, DeFosse and Myszczyszyn
Claims 29 and 31 are rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1), and further in view of DeFosse et al. (US 2011/0272365 A1), and further in view of Mante et al. (US 2019/0300405 A1).
Regarding Claim 29: Barnes in view of Mueller and DeFosse makes obvious the above limitations. Barnes does not disclose removing a portion of the sour water from the first vessel; mixing, externally to the first vessel, the portion of the sour water from the first vessel together with a second portion of the first hydrocarbon gas to form a first mixture; and providing the first mixture to the first vessel.
However, Mante teaches removing a portion of a liquid from a vessel, optionally via an outlet disposed at the base of the vessel; mixing externally to the vessel, the portion of the liquid from the vessel together with a portion of a gas to form a mixture; and providing the mixture to the vessel; optionally, wherein said mixing is carried out using a static mixer (Dissolution column 102 contains a body of acidic pressurized liquid 110 and a gas headspace 112 above the body of acidic pressurized liquid at an over pressure. … Dissolution column 102 also comprises a recirculation liquid outlet 116 and a fluid feed inlet 118 in the bottom, which constitute the fluid recirculation loop 103. … The recirculation liquid outlet 116 provides a small portion of the acidic pressurized water to the recirculation pump 128 and the pressure of the small portion of the acidic pressurized water is elevated larger than the pressure of the acidic pressurized water in dissolution column 102. A gas and liquid mixture of O.sub.2/O.sub.3 produced by an ozone generator 124 is then mixed with the small portion of the acidic pressurized water to form a mixture of O.sub.2/O.sub.3 gas and acidic pressurized water that has gaseous and liquid phases and has a pressure greater than the pressure of the acidic pressurized water in dissolution column 102. As a result, the mixture of O.sub.2/O.sub.3 gas and acidic pressurized water flows into dissolution column 102 at the fluid feed inlet 118 through action of fluid recirculation loop 103, where the O.sub.2/O.sub.3 gas and liquid mixture is fed into dissolution column 102 by passing through fluid diffuser device 114 that is fluidly connected to fluid feed inlet 118. See at least [0403]. Also: The mixing unit 2 comprises of multiple specially designed injection nozzles and a static mixer. See at least [0394]).
Barnes, Mueller, and DeFosse suggest sequential hydrogen sulfide stripping units, upon which the claimed invention’s use of a recirculation mixing system can be seen as an improvement. However, Mante demonstrates that the prior art already knew of using a recirculation loop to inject gas and mix that gas with a liquid. One of ordinary skill in the art could have easily applied the techniques of Mante to the second stripping unit of Barnes, Mueller, and DeFosse. Further, one of ordinary skill in the art would have recognized that such an application of Mante would have resulted in superior mixing for Barnes’ stripper and thus better stripping performance. As such, the identified application of Mante and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller, DeFosse, and Mante.
Regarding Claim 31: Barnes in view of Mueller, DeFosse and Mante makes obvious the above limitations. Additionally, Mante teaches wherein said steps of removing the portion of the liquid from the first vessel; mixing externally to the second vessel, the portion of the liquid from the second vessel together with the portion of the gas to form the second mixture; and providing the second mixture to the second vessel are performed continuously during the process (the operation of system 100a generates a continuous liquid stream. See at least [0425]). The motivation to combine Barnes, Mueller, DeFosse, and Mante is the same as explained under claim 29 above, and is incorporated herein.
Alternative Claim Rejections - 35 USC § 103
Claims 1, 2, 9, and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1) and Morris (US 2015/0315485 A1).
Regarding Claim 1: Barnes discloses a process for removing hydrogen sulfide from sour water, comprising:
obtaining sour water; adjusting the pH of the sour water to a pH by addition of a first acid to form acidified sour water (Relating to sour water treatment, still with reference to FIG. 1, an acidic chemical is introduced by acidic chemical inlet feed 114 to be mixed with the predominately aqueous sour stream 110 in a first sour water treatment step in an acidic chemical mixing apparatus 112. See at least [0043]. Also: The pH of the resulting aqueous solution discharge stream 116 may be less than approximately a pH of 4 to promote the formation of approximately 99.9% of total sulfide by molar equivalent into the hydrogen sulfide species, in accordance with FIG. 2A. In some embodiments, a pH greater or less than 4 may be desirable and may be calculated by one skilled in the art such that a desired fraction of the total combined concentration of the target acid-gas exists as the conjugate base species in the resulting aqueous solution discharge stream 116. See at least [044]).
sparging the acidified sour water with a first hydrocarbon gas in a first vessel to produce a first sour gas and a sweetened water, wherein said sparging is conducted via a first sparging device disposed at or proximal to a base of the first vessel (stripping gas stream 124 is introduced to the resulting aqueous solution discharge stream 116 inside a gas-water contactor vessel 118. See at least [0046]. Also: the stripping gas is anoxic, or substantially without oxygen, being for example nitrogen, methane, natural gas. See at least [0053]. Also: the gas-water contactor vessel 118 may be a horizontal tank with an internal sparge bar for injecting the stripping gas stream 124. See at least [0048]. Also: The substantially sweet natural gas used in sour water stripping in stripping gas stream 124 enters the gas-water contactor vessel 118 at an inlet feed point located near the bottom of the vessel such that the gas has substantial contact time with the liquid in the vessel to induce sour gas stripping. See at least [0063]).
and separating the first sour gas from the sweetened water (a substantially sweetened aqueous product stream 128 discharged from the gas-water contactor vessel 118. See at least [0066]).
wherein: the pH of the acidified sour water in the first vessel is in a range during the process; and the process is conducted as a batch process (a pH greater or less than 4 may be desirable and may be calculated by one skilled in the art such that a desired fraction of the total combined concentration of the target acid-gas exists as the conjugate base species in the resulting aqueous solution discharge stream 116. See at least [044]. Also: the disclosed system and method may be implemented in a batch treatment scheme. See at least [0079]) and does not use stripping towers (the gas-water contactor vessel 118 may be a horizontal tank with an internal sparge bar for injecting the stripping gas stream 124. See at least [0048]).
Barnes does not expressly disclose wherein the pH of the acidified sour water in the first vessel is maintained substantially constant during the process.
However, Mueller teaches wherein the pH of the acidified sour water in the vessel is maintained substantially constant during the process (process fluid is flowed at 243 from any of a number of possible sources … into a degassing compartment 213, wherein the amount of entrained and dissolved gases, such as hydrogen sulfide, in the process fluid may be reduced. In one embodiment, the degassing compartment 213 comprises a pH analyzer 218a that monitors the pH of the process fluid in the degassing compartment 213. See at least [0057]. Also: pH analyzer 218a monitors the pH of the process fluid. The pH of the process fluid may be measured by any method known in the art, and is not limited herein. If the process fluid has a pH greater than 4, then acid may be added, shown at 222, to the process fluid until a pH of less than 4 is reached. In one embodiment, the pH of the process fluid is maintained between 3.0 and 3.5. In one embodiment, the acid added to the process fluid to maintain the pH may be citric acid. See at least [0058]).
Barnes provides a system that removes a desired fraction of hydrogen sulfide from sour water by lowering the pH of the water to a given level, upon which the claimed invention’s maintenance of the pH of the water at a constant level can be seen as an improvement. However, Mueller demonstrates that the prior art already knew of maintaining the pH of a liquid from which hydrogen sulfide is to be removed. One of ordinary skill in the art could have trivially applied the techniques of Mueller to the system of Barnes by maintaining the chosen pH of Barnes in the contacting vessel. Further, one of ordinary skill in the art would have recognized that such an application of Mueller would have resulted in an improved system which, by maintaining a constant pH, would maintain a constant fraction of hydrogen sulfide in its liquid discharge stream. As such, the application of Mueller would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller.
Assuming for the sake of argument that that Barnes does not disclose a pH of from 4 to 5, Morris teaches adjusting the pH of the sour water to a pH of from 4 to 5 (In certain embodiments, PH modifiers are employed. In some embodiments, the system and/or method (throughout this disclosure, any reference to the system of the invention also applies to the method and/or process, and vice versa) operates at a PH at or below 7. In some embodiments, the system operates at a PH between 1 and 7. In some embodiments, to modify the water PH downward, various acids or other low-PH materials may be used. Care should be taken to use acidic additives of such low strength per volume that they do not endanger humans or property or the environment in their transportation and use. See at least [0113]).
Barnes and Mueller suggests a system that lowers the pH to below 4 in order to remove hydrogen sulfide from sour water. Morris demonstrates that the prior art knew of lowering pH to anywhere within the range of 1 to 7 pH to remove hydrogen sulfide from water. One of ordinary skill in the art could have trivially applied the techniques of Morris to the system of Barnes and Mueller by applying Barnes and Mueller’s techniques within the 4-7 pH range of Morris. Further, one of ordinary skill in the art would have recognized that higher pHs in the range would pose less danger to humans and property. As such, the application of Morris and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller and Morris.
Regarding Claim 2: Barnes in view of Mueller and Morris makes obvious the above limitations. Additionally, Barnes discloses one or more of the following characteristics: (a) the first acid comprises hydrochloric acid, acetic acid, or a combination thereof ([0043]); (b) the first acid is hydrochloric acid ([0043]); (c) the first hydrocarbon gas is sweet gas ([0053]); (d) the pH is maintained substantially constant during the process; (e) the process is conducted in an oxygen-free environment; and (f) the process further comprises heating the first vessel during the process
Regarding Claim 9: Barnes in view of Mueller and Morris makes obvious the above limitations. Additionally, Barnes discloses wherein the first sparging device comprises at least one sparging finger fluidly connected to a source of the first hydrocarbon gas and disposed horizontally within the first vessel, wherein the sparging finger comprises a pipe with a plurality of orifices for releasing the first hydrocarbon gas into the first vessel (the gas-water contactor vessel 118 may be a horizontal tank with an internal sparge bar for injecting the stripping gas stream 124. See at least [0048]. Also: The substantially sweet natural gas used in sour water stripping in stripping gas stream 124 enters the gas-water contactor vessel 118 at an inlet feed point located near the bottom of the vessel such that the gas has substantial contact time with the liquid in the vessel to induce sour gas stripping. See at least [0063]).
Regarding Claim 16: Barnes in view of Mueller and Morris makes obvious the above limitations. Additionally, Barnes discloses incinerating the first sour gas following the step of separating the first sour gas from the sweetened water (sour stripping gas stream 662 was instead transferred to a flare stack where both methane and the hydrogen sulfide vapors stripped from reduced pH aqueous mixture stream 616 in sour water stripper 660 were combusted and burned in the presence of oxygen. See at least [0109]); sending the first sour gas to a vapor recovery unit to be sweetened and recycled to the process following the step of separating the first sour gas from the sweetened water (process unit for sour gas treatment 122 may be designed by one skilled in the art to sufficiently remove sour components from a gas stream. See at least [0058]. Also: process unit for sour gas treatment 122 is used to generate a stream of substantially sweet gas, such as stripping gas stream 124, that may be further used in a gas stripping step in a concurrent water treatment process. See at least [0059]); or sending the sweetened water to a storage tank following the step of separating the first sour gas from the sweetened water.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1) and Morris (US 2015/0315485 A1), and further in view of Myszczyszyn (WO2015154168 A1).
Regarding Claim 10: Barnes in view of Mueller and Morris makes obvious the above limitations. However, Barnes does not disclose one or more of the following characteristics: (a) a plurality of orifices are evenly spaced apart from one another; and (b) the first sparging device comprising a plurality of sparging fingers. However, Myszczyszyn teaches (a) a plurality of orifices are evenly spaced apart from one another (Tn one embodiment according to the present invention, the apertures were located 12 inches apart on ¼ inch stainless steel tubing and had a diameter of 1/8 inch. See at least second paragraph of page 5); and (b) the first sparging device comprising a plurality of sparging fingers (See at least Fig. 4).
Barnes, Mueller, and Morris suggest a hydrogen sulfide stripping unit which uses a sparge bar to introduce the stripping gas into the liquid, which differs from the claimed invention by the substitution of Barnes’s sparge bar with a more specific sparging system using regularly placed gas outlets or multiple gas lines. Myszczyszyn demonstrates that the prior art already knew of sparging systems which use regularly placed gas outlets or multiple gas lines to remove hydrogen sulfide. One of ordinary skill in the art could have easily substituted the bubbler of Myszczyszyn into the system of Barnes, Mueller, and Morris. Further, one of ordinary skill in the art would have recognized that such a substitution would have predictably resulted in a simpler and lower cost method of introducing gas into the liquid (Myszczyszyn, Paragraph 6 of Page 4). As such, the identified substitution and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller, Morris, and Myszczyszyn.
Claims 12 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1) and Morris (US 2015/0315485 A1), and further in view of Mante et al. (US 2019/0300405 A1).
Regarding Claim 12: Barnes in view of Mueller and Morris makes obvious the above limitations. Barnes does not disclose removing a portion of the sour water from the first vessel; mixing, externally to the first vessel, the portion of the sour water from the first vessel together with a second portion of the first hydrocarbon gas to form a first mixture; and providing the first mixture to the first vessel.
However, Mante teaches removing a portion of a liquid from a first vessel, optionally via an outlet disposed at the base of the first vessel; mixing externally to the first vessel, the portion of the liquid from the first vessel together with a portion of a gas to form a first mixture; and providing the first mixture to the first vessel; optionally, wherein said mixing is carried out using a first static mixer (Dissolution column 102 contains a body of acidic pressurized liquid 110 and a gas headspace 112 above the body of acidic pressurized liquid at an over pressure. … Dissolution column 102 also comprises a recirculation liquid outlet 116 and a fluid feed inlet 118 in the bottom, which constitute the fluid recirculation loop 103. … The recirculation liquid outlet 116 provides a small portion of the acidic pressurized water to the recirculation pump 128 and the pressure of the small portion of the acidic pressurized water is elevated larger than the pressure of the acidic pressurized water in dissolution column 102. A gas and liquid mixture of O.sub.2/O.sub.3 produced by an ozone generator 124 is then mixed with the small portion of the acidic pressurized water to form a mixture of O.sub.2/O.sub.3 gas and acidic pressurized water that has gaseous and liquid phases and has a pressure greater than the pressure of the acidic pressurized water in dissolution column 102. As a result, the mixture of O.sub.2/O.sub.3 gas and acidic pressurized water flows into dissolution column 102 at the fluid feed inlet 118 through action of fluid recirculation loop 103, where the O.sub.2/O.sub.3 gas and liquid mixture is fed into dissolution column 102 by passing through fluid diffuser device 114 that is fluidly connected to fluid feed inlet 118. See at least [0403]. Also: The mixing unit 2 comprises of multiple specially designed injection nozzles and a static mixer. See at least [0394]).
Barnes, Mueller, and Morris suggest a hydrogen sulfide stripping unit, upon which the claimed invention’s use of a recirculation mixing system can be seen as an improvement. However, Mante demonstrates that the prior art already knew of using a recirculation loop to inject gas and mix that gas with a liquid. One of ordinary skill in the art could have easily applied the techniques of Mante to the stripping unit of Barnes, Mueller, and Morris. Further, one of ordinary skill in the art would have recognized that such an application of Mante would have resulted in superior mixing for Barnes’ stripper and thus better stripping performance. As such, the identified application of Mante and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller, Morris and Mante.
Regarding Claim 14: Barnes in view of Mueller, Morris, and Mante makes obvious the above limitations. Additionally, Mante teaches wherein said steps of removing the portion of the liquid from the first vessel; mixing externally to the first vessel, the second portion of the liquid from the first vessel together with the first portion of the gas to form the first mixture; and providing the first mixture to the first vessel are performed continuously during the process (the operation of system 100a generates a continuous liquid stream. See at least [0425]). The motivation to combine Barnes, Mueller, Morris, and Mante is the same as explained under claim 12 above, and is incorporated herein.
Claims 18, 19, 26, 33, 37, and 38 are rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1) and Morris (US 2015/0315485 A1), and further in view of DeFosse et al. (US 2011/0272365 A1).
Regarding Claim 18: Barnes in view of Mueller and Morris makes obvious the above limitations. As previously noted above, Barnes discloses providing water to a vessel; a pH of from 4 to 5 by addition of a acid to the water, as needed; sparging the acidified water in the vessel with a hydrocarbon gas to produce a sour gas and a sweetened water, wherein said sparging is conducted via a sparging device disposed at or proximal to a base of the vessel; and separating the sour gas from the sweetened water;. As previously noted, Mueller teaches wherein the pH acidified sour water is maintained substantially constant during the process. Barnes does not expressly disclose performing these unit operations a subsequent time.
However, DeFosse teaches providing the sweetened water formed in a first vessel to second vessel, the pH of the sweetened water at a pH by addition of a second acid to the sweetened water, as needed; mixing the acidified sweetened water with a second hydrocarbon gas to produce a second sour gas and a further sweetened water; and separating the second sour gas from the further sweetened water (See Fig. 1. Also: The water from the first separator 20A, while containing less hydrogen sulfide than the sour water being input into the system 100, can still contain some hydrogen sulfide dissolved in the water. This remaining water can be routed to a subsequent stage with a second mixer 10B and a second separator 20B to remove some of the hydrogen sulfide remaining in the water. See at least [0023]. Also: In one aspect, a pH adjustment module 6B can be used to lower the pH of the water before it is routed to the second mixer 10B. See at least [0024]. Also: The second mixer 10B can be used to mix water from the first separator 20A with stripper gas from the stripper gas feed inlet 4 and then the mixture can be routed to the second separator 20B to separate another gas portion from the water. See at least [0025]).
Barnes, Mueller, and Morris suggest a contactor system which strips hydrogen sulfide from a sour water stream to produce sweetened water, upon which the claimed invention’s repetition of this process can be seen as an improvement. However, DeFosse demonstrates that the prior art already knew of repeating the process of stripping hydrogen sulfide from a sour water stream. One of ordinary skill in the art could have trivially applied DeFosse’s repetition of the process with the contactor system equipment of Barnes, Mueller, and Morris. Further, one of ordinary skill in the art would have recognized that such an application of DeFosse would have resulted in an improved system which would produce a water stream with a reduced amount of hydrogen sulfide relative to the base techniques of Barnes and Mueller. As such, the identified application of DeFosse and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller, Morris, and DeFosse.
Regarding Claim 19: Barnes in view of Mueller, Morris, and DeFosse makes obvious the above limitations. As previously noted, Barnes discloses one or more of the following characteristics: (a) the acid comprises hydrochloric acid, acetic acid, or a combination thereof ([0043]); (b) the acid is hydrochloric acid ([0043]); (c) the hydrocarbon gas is sweet gas ([0053]); (d) the pH is maintained substantially constant during the process; (e) the process is conducted in an oxygen-free environment; and (f) the process further comprises heating the vessel during the process. The motivation to combine Barnes, Mueller, Morris, and DeFosse is the same as explained under claim 18 above, and is incorporated herein.
Regarding Claim 26: Barnes in view of Mueller, Morris, and DeFosse makes obvious the above limitations. As previously noted, Barnes discloses wherein the sparging device comprises at least one sparging finger fluidly connected to a source of the hydrocarbon gas and disposed horizontally within the vessel, wherein the at least one sparging finger comprises a pipe with a plurality of orifices for releasing the hydrocarbon gas into the vessel (the gas-water contactor vessel 118 may be a horizontal tank with an internal sparge bar for injecting the stripping gas stream 124. See at least [0048]. Also: The substantially sweet natural gas used in sour water stripping in stripping gas stream 124 enters the gas-water contactor vessel 118 at an inlet feed point located near the bottom of the vessel such that the gas has substantial contact time with the liquid in the vessel to induce sour gas stripping. See at least [0063]). The motivation to combine Barnes, Mueller, Morris, and DeFosse is the same as explained under claim 18 above, and is incorporated herein.
Regarding Claim 33: Barnes in view of Mueller, Morris, and DeFosse makes obvious the above limitations. As previously noted, Barnes discloses incinerating the sour gas following the step of separating the sour gas from the sweetened water (sour stripping gas stream 662 was instead transferred to a flare stack where both methane and the hydrogen sulfide vapors stripped from reduced pH aqueous mixture stream 616 in sour water stripper 660 were combusted and burned in the presence of oxygen. See at least [0109]); sending the sour gas to a vapor recovery unit to be sweetened and recycled to the process following the step of separating the sour gas from the sweetened water (process unit for sour gas treatment 122 may be designed by one skilled in the art to sufficiently remove sour components from a gas stream. See at least [0058]. Also: process unit for sour gas treatment 122 is used to generate a stream of substantially sweet gas, such as stripping gas stream 124, that may be further used in a gas stripping step in a concurrent water treatment process. See at least [0059]); or sending the sweetened water to a storage tank following the step of separating the second sour gas from the sweetened water. The motivation to combine Barnes, Mueller, Morris, and DeFosse is the same as explained under claim 18 above, and is incorporated herein.
Regarding Claim 37: Barnes in view of Mueller, Morris, and DeFosse makes obvious the above limitations. Additionally, DeFosse teaches providing the further sweetened water formed in the second vessel to a third vessel for further sweeting of the water (The water from the second separator can be routed through a last stage containing a third mixer 10C and a third separator 20C. See at least [0026]. Also: From the third separator 20C, remaining water can be used to form the final water product containing significantly reduced levels of hydrogen sulfide (sweet water) in relation to the sour water that was input into the system 100. See at least [0028]). The motivation to combine Barnes, Mueller, Morris, and DeFosse is the same as explained under claim 18 above, and is incorporated herein.
Regarding Claim 38: Barnes in view of Mueller, Morris, and DeFosse makes obvious the above limitations. Additionally, DeFosse teaches one or more of the following characteristics: (a) the first acid and the second acid are the same acid (In one embodiment, the pH of the sour water is lowered by the addition of an acid, for example, hydrochloric acid. See at least [0008], [0013], and Fig. 1), (b) the first acid and the second acid are hydrochloric acid (In one embodiment, the pH of the sour water is lowered by the addition of an acid, for example, hydrochloric acid. See at least [0008], [0013], and Fig. 1), (c) the first hydrocarbon gas and the second hydrocarbon gas are the same gas (See Fig. 1. Also: A stripper gas can be provided via stripper gas feed inlet 4 for supplying a stripper gas that will be mixed with the sour water. The stripper gas can be methane, CO.sub.2, a mixture of methane and CO.sub.2, steam, nitrogen, a mixture of any of these gases, etc. See at least [0015]); (d) the first hydrocarbon gas and the second hydrocarbon gas are sweet gas (See Fig. 1. Also: A stripper gas can be provided via stripper gas feed inlet 4 for supplying a stripper gas that will be mixed with the sour water. The stripper gas can be methane, CO.sub.2, a mixture of methane and CO.sub.2, steam, nitrogen, a mixture of any of these gases, etc. See at least [0015]). The motivation to combine Barnes, Mueller, Morris, and DeFosse is the same as explained under claim 18 above, and is incorporated herein.
Claim 27 is rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1) and Morris (US 2015/0315485 A1), and further in view of DeFosse et al. (US 2011/0272365 A1), and further in view of Myszczyszyn (WO2015154168 A1).
Regarding Claim 27: Barnes in view of Mueller, Morris, and DeFosse makes obvious the above limitations. However, Barnes does not disclose one or more of the following characteristics: (a) a plurality of orifices are evenly spaced apart from one another; and (b) the second sparging device comprising a plurality of sparging fingers. However, Myszczyszyn teaches (a) a plurality of orifices are evenly spaced apart from one another (Tn one embodiment according to the present invention, the apertures were located 12 inches apart on ¼ inch stainless steel tubing and had a diameter of 1/8 inch. See at least second paragraph of page 5); and (b) the sparging device comprising a plurality of sparging fingers (See at least Fig. 4).
Barnes, Mueller, Morris, and DeFosse suggest sequential hydrogen sulfide stripping units which use sparge bars to introduce the stripping gas into the liquid, which differs from the claimed invention by the substitution of Barnes’s sparge bars with a more specific sparging system using regularly placed gas outlets or multiple gas lines. Myszczyszyn demonstrates that the prior art already knew of sparging systems which use regularly placed gas outlets or multiple gas lines to remove hydrogen sulfide. One of ordinary skill in the art could have easily substituted the bubbler of Myszczyszyn into the system of Barnes, Mueller, Morris, and DeFosse. Further, one of ordinary skill in the art would have recognized that such a substitution would have predictably resulted in a simpler and lower cost method of introducing gas into the liquid (Myszczyszyn, Paragraph 6 of Page 4). As such, the identified substitution and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller, Morris, DeFosse and Myszczyszyn
Claims 29 and 31 are rejected under 35 U.S.C. 103 as being unpatentable over Barnes et al. (US 2016/0200592 A1) in view of Mueller et al. (US 2007/0199902 A1) and Morris (US 2015/0315485 A1), and further in view of DeFosse et al. (US 2011/0272365 A1), and further in view of Mante et al. (US 2019/0300405 A1).
Regarding Claim 29: Barnes in view of Mueller, Morris, and DeFosse makes obvious the above limitations. Barnes does not disclose removing a portion of the sour water from the first vessel; mixing, externally to the first vessel, the portion of the sour water from the first vessel together with a second portion of the first hydrocarbon gas to form a first mixture; and providing the first mixture to the first vessel.
However, Mante teaches removing a portion of a liquid from a vessel, optionally via an outlet disposed at the base of the vessel; mixing externally to the vessel, the portion of the liquid from the vessel together with a portion of a gas to form a mixture; and providing the mixture to the vessel; optionally, wherein said mixing is carried out using a static mixer (Dissolution column 102 contains a body of acidic pressurized liquid 110 and a gas headspace 112 above the body of acidic pressurized liquid at an over pressure. … Dissolution column 102 also comprises a recirculation liquid outlet 116 and a fluid feed inlet 118 in the bottom, which constitute the fluid recirculation loop 103. … The recirculation liquid outlet 116 provides a small portion of the acidic pressurized water to the recirculation pump 128 and the pressure of the small portion of the acidic pressurized water is elevated larger than the pressure of the acidic pressurized water in dissolution column 102. A gas and liquid mixture of O.sub.2/O.sub.3 produced by an ozone generator 124 is then mixed with the small portion of the acidic pressurized water to form a mixture of O.sub.2/O.sub.3 gas and acidic pressurized water that has gaseous and liquid phases and has a pressure greater than the pressure of the acidic pressurized water in dissolution column 102. As a result, the mixture of O.sub.2/O.sub.3 gas and acidic pressurized water flows into dissolution column 102 at the fluid feed inlet 118 through action of fluid recirculation loop 103, where the O.sub.2/O.sub.3 gas and liquid mixture is fed into dissolution column 102 by passing through fluid diffuser device 114 that is fluidly connected to fluid feed inlet 118. See at least [0403]. Also: The mixing unit 2 comprises of multiple specially designed injection nozzles and a static mixer. See at least [0394]).
Barnes, Mueller, Morris, and DeFosse suggest sequential hydrogen sulfide stripping units, upon which the claimed invention’s use of a recirculation mixing system can be seen as an improvement. However, Mante demonstrates that the prior art already knew of using a recirculation loop to inject gas and mix that gas with a liquid. One of ordinary skill in the art could have easily applied the techniques of Mante to the second stripping unit of Barnes, Mueller, Morris, and DeFosse. Further, one of ordinary skill in the art would have recognized that such an application of Mante would have resulted in superior mixing for Barnes’ stripper and thus better stripping performance. As such, the identified application of Mante and the claimed invention would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention in view of the disclosure of Barnes and the teachings of Mueller, Morris, DeFosse, and Mante.
Regarding Claim 31: Barnes in view of Mueller, Morris, DeFosse and Mante makes obvious the above limitations. Additionally, Mante teaches wherein said steps of removing the portion of the liquid from the first vessel; mixing externally to the second vessel, the portion of the liquid from the second vessel together with the portion of the gas to form the second mixture; and providing the second mixture to the second vessel are performed continuously during the process (the operation of system 100a generates a continuous liquid stream. See at least [0425]). The motivation to combine Barnes, Mueller, DeFosse, and Mante is the same as explained under claim 29 above, and is incorporated herein.
Response to Arguments
Applicant’s Argument Regarding 103 Rejections of claims 1, 2, 9, 16, and 35:
The rationale provided by the Examiner does not adequately account for what Barnes itself teaches about pH behavior during the stripping process … Barnes thus recognizes that the pH of the water increases during gas stripping as dissolved hydrogen sulfide – an acid gas – is removed from the aqueous phase. Critically, Barnes does not identify this pH change as a deficiency, does not suggest it impairs stripping performance, and does not propose any mechanism to counteract it.
The Examiner’s rationale assumes that maintaining a constant pH during gas stripping would be recognized by a person of ordinary skill as an “improvement” to Barnes. However, the Examiner has not pointed to any teaching in Barnes – or elsewhere in the record – that identifies pH drift during anoxic gas stripping as a performance limitation, or suggests active pH maintenance during the stripping step would enhance hydrogen sulfide removal.
Mueller’s pH maintenance teaching at [0058] is directed to maintaining conditions suitable for Mueller’s own multi-mechanism treatment process (mechanical degassing, optional aeration, and chemical scavenging of drilling fluids). As person of ordinary skill reading Mueller would understand the pH maintenance at [0058] as part of an integrated process designed for a specific treatment context. The Examiner has not explained why a person of ordinary skill would extract the pH maintenance concept from this context and apply it to the fundamentally different process of Barnes.
The express teaching of Barnes is thus that a pH below 4 provides the most complete conversion of sulfide species to hydrogen sulfide gas. … Both references therefore point a person of ordinary skill away from the claimed range of 4 to 5 and towards a pH below 4.
Under MPEP 2144.05(III)(A), a prima facie case of obviousness based on overlapping or close ranges may be rebutted by a showing that the claimed range produces results that differ in kind, not merely in degree, form those at the prior art values. The present specification discloses that maintaining pH in the range of from about 4 to 5 in conjunction with batch sparging yielded results that were “impressive and considered viable.” … As such, the finding that effective batch H2S removal is achievable at pH 4 to 5 … is noteworthy and should be given due consideration.
Examiner’s Response: Applicant's arguments filed 3 June 2026 have been fully considered but they are not persuasive.
Primary references are not required to recognize their deficiency in order to be used in a 103 rejection as a system to be improved upon.
Per MPEP 2144.I, “The rationale to modify or combine the prior art does not have to be expressly stated in the prior art; the rationale may be expressly or impliedly contained in the prior art or it may be reasoned from knowledge generally available to one of ordinary skill in the art, established scientific principles, or legal precedent established by prior case law.” As Applicant acknowledges “Barnes thus recognizes that the pH of the water increases during gas stripping.” One of ordinary skill in the art further would know that the proportion of the sulfide in the H2S form capable of degassing is a function of pH. One of ordinary skill in the art could then not fail to recognize that an increasing pH would decrease the amount of sulfide removal, and that maintain the pH would improve the system by avoiding that decrease. Or as stated in the current and prior rejections: “one of ordinary skill in the art would have recognized that such an application of Mueller would have resulted in an improved system which, by maintaining a constant pH, would maintain a constant fraction of hydrogen sulfide in its liquid discharge stream.”
Examiner disagrees that the processes of Barnes and Mueller are “fundamentally different”. The relevant process are both for degassing hydrogen sulfide under adjusted pH conditions. Further, Examiner notes that the rejection provides a motivation that does not appear to be addressed by Applicant’s argument: “one of ordinary skill in the art would have recognized that such an application of Mueller would have resulted in an improved system which, by maintaining a constant pH, would maintain a constant fraction of hydrogen sulfide in its liquid discharge stream.
The relevance of Applicant’s argument that the references “point” away from the claimed invention is unclear. “Pointing away” is not “teaching away.” Per MPEP 2145(X)(D)(1), “a reference does not teach away if it merely expresses a general preference for an alternative invention but does not criticize, discredit or otherwise discourage investigation into the invention claimed.” Further, Barnes does not consistently “point away” from the claimed invention. Barnes at [0044] states “In some embodiments, a pH greater or less than 4 may be desirable and may be calculated by one skilled in the art such that a desired fraction of the total combined concentration of the target acid-gas exists as the conjugate base species in the resulting aqueous solution discharge stream 116.” One of ordinary skill in the art understands this to mean that someone might want a pH greater than 4 depending on the proportion of bisulfide they want in the liquid. Such a teaching does not “point away” from the claimed invention.
The disclosure at [0096] states: “FIGS. 8(e), 8(f), and 8(g) show the experimental conditions and results of three separate experiments using this system and process. As noted above, the results from these tests were impressive and considered viable.” Figures 8€ and 8(g) involve tests mostly occurring at a pH of 4, but figure 8(f) involves a test over a pH range of 6-8. The fact that this other range was disclosed as equally “impressive and considered viable” indicates that the claimed range is not critical and does not “differ in kind.”
Additional Considerations
The prior art made of record and not relied upon that is considered pertinent to applicant’s disclosure can be found in the PTO-892 of the prior office actions dated 25 September 2023 and 16 January 2024.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Bion A Shelden whose telephone number is (571)270-0515. The examiner can normally be reached M-F, 12pm-10pm EST.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Kambiz Abdi can be reached at (571) 272-6702. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
/Bion A Shelden/Primary Examiner, Art Unit 3685 2026-08-21
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