DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
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.
Claim(s) 1, 3, 7-9, 18, and 20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zardi (US20090292140) in view of Poppa (US20200306663) in view of Zwart (US20100168473) in view of Gevers (US20110118506).
Claim(s) 5 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zardi in view of Poppa in view of Zwart in view of Gevers further in view of Jonckers (US5767313).
Claim(s) 6, 16, and 17 is/are rejected under 35 U.S.C. 103 as being unpatentable over Zardi in view of Poppa in view of Zwart in view of Gevers in view of Scotto (US20160082408).
Rejection in view of Zardi, Poppa, Zwart, and Gevers
Claim 1: Zardi teaches a urea production plant comprising a high pressure (HP) synthesis section comprising a reactor, a thermal stripper that is a self stripper, and a high pressure carbamate condenser (Abstract teaches this a method for a urea plant. Figure 1 shows the urea plant. There is a HP synthesis section or loop 2 as taught in [0035]. [0036] teaches there is a reactor 5, condenser 6, and stripper 7. [0034] teaches figure 1 shows a conventional self stripping or thermal stripping urea plant 1.), wherein the high pressure carbamate condenser comprises a shell-and-tube heat exchanger comprising a tube bundle and a shell space ([0011] teaches the carbamate condenser is a conventional horizonal shell and tube condenser. [0019]-[0020] teach that the invention uses the conventional condenser.), and wherein the tube bundle of the condenser is a horizontal tube bundle ([0037] teaches condenser 6 is a horizonal shell and tube unit.); the plant further comprising a medium pressure (MP) recovery section ([0035] teaches a medium pressure treatment section 3.), wherein the MP recovery section has a carbamate recycle flow line and a separate ammonia recycle flow line to the HP synthesis section ([0042] teaches that the MP section 3 obtains a solution with low carbamate content that is further treated in the low pressure section 4. There is gaseous ammonia from column 11 that is condensed and recycled to reactor 5.).
Zardi does not explicitly teach the plant comprises a gas flow line from a gas outlet of the thermal stripper to a gas inlet of said shell space, further wherein the shell space of the condenser comprises an outlet for a fluid stream containing both gas and liquid, which outlet is connected to a HP gas/liquid separator having a gas outlet and a liquid outlet; wherein the liquid outlet of the separator is connected through an ejector to an inlet of the reactor, to supply a liquid containing carbamate, urea and water to the reactor. Figure 1 and [0037] teaches that the condenser 6 receives a gaseous phase discharged from stripper 7 via lines 32 and 33. However this is for condensing on the tube side.
Poppa teaches an analogous device with a carbamate condenser, the plant comprises a gas flow line from a gas outlet of the thermal stripper to a gas inlet of said shell space ([0093] teaches the stripper sends mixed gas SC to the condenser HPCC. [0094] and figure 3 teaches the condensation is carried out in the shell side of the HPCC.), and wherein the tube bundle of the condenser is a horizontal tube bundle (Figure 3 shows this is horizontal tubes.), the condenser has a gas outlet and a separate liquid outlet both from the shell space, wherein the shell side liquid outlet is connected indirectly with the reactor (Figure 3 shows the HPCC has a gas outlet G3 and a liquid outlet C that is in the shell space. The liquid outlet C is connected to the reactor R). It would have been obvious to one of ordinary skill before the effective filing date of the invention to use the condenser of Poppa in the device of Zardi because the simple substitution of one known element for another is within the ambit of a person of ordinary skill when the substitution would be expected to produce predictable results. See MPEP 2143, I(B). In this case the substitution would likely produce predictable results because the condenser of Poppa is/are an equivalent of the condenser of Zardi as they are both meant to be used for carbamate. Poppa also teaches in [0014] that the HPCC has an advantage in that condensation in the spell space also provides a simple construction wherein the condensate has sufficient residence time in the condenser.
Zardi and Poppa do not explicitly state the shell side liquid outlet is connected indirectly with the reactor through a high pressure (HP) ejector.
Zwart teaches an analogous device that has a condenser with a gas and liquid outlet, in which the liquid outlet is connected to a high pressure ejector to the reactor (Figure 1 and [0044].). Zwart teaches in [0001]-[0007] that ejectors are known in the art to connect the condenser and reactor to transfer condensate solution to the reactor. Zwart also teaches in [0007] this is an invention for connecting a submerged condenser and a reactor with an ejector. Poppa teaches in [0014] the HPCC is a submerged condenser.
It would have been obvious to one of ordinary skill before the effective filing date of the invention to have an appropriate connector for the condensate to the reactor, such as a HP ejector taught by Zwart in the device of Zardi and Poppa, as Zwart teaches that this is a method of connecting the submerged condenser to a reactor to prepare urea on ground level and Poppa teaches a submerged condenser connected to a reactor as seen in figure 3.
Zardi, Poppa, and Zwart do not explicitly teach the condenser comprises a sparger in the shell space for distributing gas from the thermal stripper into the shell space. Zardi teaches that this is a horizontal shell and tube condenser that gets gas from the stripper ([0037] teaches condenser 6 is a horizonal shell and tube unit. Rejection of claim 1 teaches the stripper connection).
Gevers teaches an analogous device for making urea (abstract). Gevers teaches that a sparger allows for distribution of a mixed gas stream from a stripper that is fed via a sparger into the condenser section ([0038]). Gevers teaches that a sparger is useful for optimizing distribution ([0011] teaches this optimized distribution of ammonia, however the main benefit of a sparger being able to optimize distribution of a fluid applies still.). It would have been obvious to one of ordinary skill before the effective filing of the invention to use a sparger as taught by Gevers in the device of Zardi, Poppa, and Zwart as Gevers teaches that a sparger is able to optimize and distribute the flow of a fluid in urea processes, and also uses one in the condenser.
Claim 3: Poppa teaches the tube bundle of the condenser is a U-shaped tube bundle (Figure 3 shows the tubes T1 and T2 are U shaped.).
Claim 7: Zardi teaches the shell space of the condenser comprises an outlet for fluid comprising liquid and wherein the plant comprises a liquid flow connection from said outlet to the reactor ([0043] teaches that the output of condenser 6 is a carbamate solution at line 35 that is recycled to the reactor 5.).
Claim 8: Poppa teaches the condenser is a vessel comprising a horizontal U-shaped tube bundle, a condensation zone and a reaction zone (Figure 3 shows the U shape T1 and T2. Since condensation zone and reaction zone are not defined, these can be just different portions of the HPCC.).
Claim 9: Poppa teaches condenser comprises a shell, wherein the shell is provided with a lining of urea grade corrosion resistant steel (HPCC has the shell space inside the housing. [0044] teaches that the inside of the shell is provided of internal lining made of corrosion resistant material or urea grade steel.).
Claim 18: Poppa teaches the lining of urea grade corrosion resistant steel is a lining in duplex ferritic-austenitic stainless steel ([0044] teaches the use of duplex austenitic-ferritic stainless steel.).
Claim 20: Zardi teaches a urea production plant comprising a high pressure (HP) synthesis section comprising a reactor, a thermal stripper that is a self stripper, and a high pressure carbamate condenser (Abstract teaches this a method for a urea plant. Figure 1 shows the urea plant. There is a HP synthesis section or loop 2 as taught in [0035]. [0036] teaches there is a reactor 5, condenser 6, and stripper 7. [0034] teaches figure 1 shows a conventional self stripping or thermal stripping urea plant 1.), wherein the high pressure carbamate condenser comprises a shell-and-tube heat exchanger comprising a tube bundle and a shell space ([0011] teaches the carbamate condenser is a conventional horizonal shell and tube condenser. [0019]-[0020] teach that the invention uses the conventional condenser.), and wherein the tube bundle of the condenser is a horizontal tube bundle ([0037] teaches condenser 6 is a horizonal shell and tube unit.); the plant further comprising a medium pressure (MP) recovery section ([0035] teaches a medium pressure treatment section 3.), wherein the MP recovery section has a carbamate recycle flow line and a separate ammonia recycle flow line to the HP synthesis section ([0042] teaches that the MP section 3 obtains a solution with low carbamate content that is further treated in the low pressure section 4. There is gaseous ammonia from column 11 that is condensed and recycled to reactor 5.).
Zardi does not explicitly teach the plant comprises a gas flow line from a gas outlet of the thermal stripper to a gas inlet of said shell space, further wherein the condenser has a gas outlet and a separate liquid outlet both from the shell space, wherein the shell side liquid outlet is connected indirectly with the reactor through a high pressure (HP) ejector. Figure 1 and [0037] teaches that the condenser 6 receives a gaseous phase discharged from stripper 7 via lines 32 and 33. However this is for condensing on the tube side.
Poppa teaches an analogous device with a carbamate condenser, the plant comprises a gas flow line from a gas outlet of the thermal stripper to a gas inlet of said shell space ([0093] teaches the stripper sends mixed gas SC to the condenser HPCC. [0094] and figure 3 teaches the condensation is carried out in the shell side of the HPCC.), and wherein the tube bundle of the condenser is a horizontal tube bundle (Figure 3 shows this is horizontal tubes.), the condenser has a gas outlet and a separate liquid outlet both from the shell space, wherein the condenser has a gas outlet and a separate liquid outlet both from the shell space, wherein the shell side liquid outlet is connected indirectly with the reactor (Figure 3 shows the HPCC has a gas outlet G3 and a liquid outlet C that is in the shell space. The liquid outlet C is connected to the reactor R). It would have been obvious to one of ordinary skill before the effective filing date of the invention to use the condenser of Poppa in the device of Zardi because the simple substitution of one known element for another is within the ambit of a person of ordinary skill when the substitution would be expected to produce predictable results. See MPEP 2143, I(B). In this case the substitution would likely produce predictable results because the condenser of Poppa is/are an equivalent of the condenser of Zardi as they are both meant to be used for carbamate. Poppa also teaches in [0014] that the HPCC has an advantage in that condensation in the spell space also provides a simple construction wherein the condensate has sufficient residence time in the condenser.
Zardi and Poppa do not explicitly state the shell side liquid outlet is connected indirectly with the reactor through a high pressure (HP) ejector.
Zwart teaches an analogous device that has a condenser with a gas and liquid outlet, in which the liquid outlet is connected to a high pressure ejector to the reactor (Figure 1 and [0044].). Zwart teaches in [0001]-[0007] that ejectors are known in the art to connect the condenser and reactor to transfer condensate solution to the reactor. Zwart also teaches in [0007] this is an invention for connecting a submerged condenser and a reactor with an ejector. Poppa teaches in [0014] the HPCC is a submerged condenser.
It would have been obvious to one of ordinary skill before the effective filing date of the invention to have an appropriate connector for the condensate to the reactor, such as a HP ejector taught by Zwart in the device of Zardi and Poppa, as Zwart teaches that this is a method of connecting the submerged condenser to a reactor to prepare urea on ground level and Poppa teaches a submerged condenser connected to a reactor as seen in figure 3.
Zardi, Poppa, and Zwart do not explicitly teach the condenser comprises a sparger in the shell space for distributing gas from the thermal stripper into the shell space. Zardi teaches that this is a horizontal shell and tube condenser that gets gas from the stripper ([0037] teaches condenser 6 is a horizonal shell and tube unit. Rejection of claim 1 teaches the stripper connection).
Gevers teaches an analogous device for making urea (abstract). Gevers teaches that a sparger allows for distribution of a mixed gas stream from a stripper that is fed via a sparger into the condenser section ([0038]). Gevers teaches that a sparger is useful for optimizing distribution ([0011] teaches this optimized distribution of ammonia, however the main benefit of a sparger being able to optimize distribution of a fluid applies still.). It would have been obvious to one of ordinary skill before the effective filing of the invention to use a sparger as taught by Gevers in the device of Zardi, Poppa, and Zwart as Gevers teaches that a sparger is able to optimize and distribute the flow of a fluid in urea processes, and also uses one in the condenser.
Rejection in view of Zardi, Poppa, Zwart, Gevers, and Jonckers
Claim 5: Zardi, Poppa, Zwart, and Gevers do not explicitly state the plant further comprising a steam drum connected to an outlet of the tube bundle of the condenser.
Jonckers teaches a urea plant with a condenser and a steam reservoir C in figure 1. Jonckers teaches in column 7 lines 30-43 that there is a steam reservoir attached to the heat exchanger and can further use the steam from the heat exchanger. It would have been obvious to one of ordinary skill before the effective filing date of the invention to have a steam drum connected to an outlet of the tube bundle of the condenser as Jonckers teaches that this can help collect and reuse steam from the process in other steam consuming processes.
Rejection in view of Zardi, Poppa, Zwart, Gevers, and Scotto
Claim 6: Zardi, Poppa, Zwart and Gevers do not explicitly state wherein the thermal stripper comprises stripper tubes, wherein the stripper tubes are made of Zr or Ti or are bimetallic stripper tubes. Scotto teaches in [0010] that urea plants use titanium stripper tubes for a long time and the use of bimetallic tubes were introduced in order to prevent problems of erosion.
It would have been obvious to one of ordinary skill before the effective filing date of the invention to have these bimetallic stripper tubes of Scotto in the stripper of Zardi, Poppa, Zwart, and Gevers as Scotto teaches that they can prevent erosion of internal parts of the tubes that are suitable for use in urea plants.
Claim 16: Scotto teaches the bimetallic stripper tubes comprise an external tube made of steel and an internal tube ([0010] teaches the external tube is made of steel and an internal tube made of zirconium.).
Claim 17: Scotto teaches the internal tube is made of zirconium ([0010] teaches the external tube is made of steel and an internal tube made of zirconium.).
Response to Arguments
Applicant's arguments filed 03/23/2026 have been fully considered but they are not persuasive.
Applicant argument 1):
Applicant argues in pages 7-9 that Zardi, Poppa, and Zwart do not teach the invention of claim 1. Applicant argues that Zardi does not teach a device that has a gas flow line from a gas outlet of the thermal stripper to the shell space. They argue that the OA is changing the function of Zardi by replacing it to have condensation on the shell side. The substitution would not produce predictable results without any proof as they are different types of urea production plants. They argue that one would not look at Zardi, that teaches condensation on the tube side as well as CO2 stripping to modify a urea production plant having condensation on the shell side as claimed. Applicant argues that Poppa also does not teach a thermal stripper or self stripper, instead it teaches a stripper using CO2 feed for stripping which is not thermal stripping. There is no reason to substitute the condenser of Poppa for Zardi as claimed.
Examiner response 1):
In response to Zardi: Examiner argues that Zardi teaches thermal/self stripping ([0002] teaches that self stripping or thermal stripping process is well known. [0034] also teaches that figure 1 is showing a conventional self stripping or thermal stripping urea plant.). In response to Poppa: Examiner argues that Poppa also teaches self stripping ([0039] teaches that the stripper can use CO2 or thermal stripping is also possible).
Examiner has addressed the reasoning and motivation to combine in the rejections above. Examiner has already pointed out that Zardi teaches a conventional self stripper and a condenser which is not the condenser the applicant requires. This is why a second reference of Poppa is brought in to teach a condenser used in urea production. Poppa also teaches in [0014] that the HPCC has an advantage in that condensation in the spell space also provides a simple construction wherein the condensate has sufficient residence time in the condenser. This appears to be the same reasoning applicant provides in page 9. Therefore there is sufficient reason to combine the condenser of Poppa to a conventional and well known urea synthesis process as taught in Zardi.
Applicant argument 2):
Applicant argues in pages 10 that Examiner is taking Zardi out of context as Zardi is dedicated to teaching a modified CO2 stripping plant.
Examiner response 2):
Examiner is again only using Zardi to show an example of a convention or well known urea synthesis process. There is no other part of Zardi that is being relied upon except stating the conventional or well known process and figure 1. While Zardi does have multiple embodiments, one of the embodiments is the conventional system of figure 1, which is what is being used.
Applicant argument 3):
Applicant argues in page 10 there is no reason to combine the invention of Zwart as Zwart relates to a CO2 stripping device instead of a self stripping device.
Examiner response 3):
Zwart also teaches in [0007] this is an invention for connecting a submerged condenser and a reactor with an ejector. Poppa teaches in [0014] the HPCC is a submerged condenser. Therefore there would be reason to combine as both are being used for a submerged condensed connected to a reactor.
Applicant argument 4):
Applicant argues throughout the response that examiner has used impermissible hindsight analysis to pull individual elements from multiple references to read upon the applicant’s claim.
Examiner response 4):
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). In this case Zardi teaches a self stripping urea plant that uses a condenser, Poppa teaches a urea production plant that uses a different kind of condenser, and Zwart teaches the use of ejectors in these processes.
Conclusion
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/CHRISTOPHER P JONES/Primary Examiner, Art Unit 1776
/P.Y.S/Examiner, Art Unit 1776 03/30/2026