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 Status
The claims are not substantially ended.
Response to Arguments
Applicant's arguments filed 11/25/25 have been fully considered but they are not persuasive.
The remarks argue the following:
Applicant notes that, according to claim 17, the ammonia synthesis loop is required to comprise: a catalytic converter, a circulator; a converter feed line from the circulator to the converter, a condensation section, a separation section, a recycle line from the separation section to a suction of the circulator. Hence, in addition to the distinguishing technical features already identified by the PTO, Applicant further notes that the PTO has not demonstrated that Johanning discloses:
(vi) aconverter feed line from the circulator to the converter, because Johanning has no circulator and thus no such converter feed line;
(vii) an ammonia synthesis loop because, in view of the recognized structural differences (ii), (iii.a), (iii.b), (iv.a), plus the additional feature (vi), the PTO has not demonstrated that Johanning discloses an ammonia synthesis loop according to the claimed process—not only due to the missing apparatuses, but also because the claimed connections and process streams belonging to the claimed process are also missing;
(viii) an ammonia synthesis loop at a full load condition, because, in view of (vii), Johanning has no ammonia synthesis loop according to the claim;
(ix) the ammonia synthesis loop at a partial load condition, whereby recognized feature (v) (“does not teach that the make-up synthesis gas is less than a nominal is a consequence of controlling the ammonia synthesis loop at a partial load condition.
The remarks are respectfully disputed. As to the argument in (vi), it was explained in the prior rejection that Johanning does not teach reintroducing the bypass stream at the suction side of the circulator. Benner describes feeding a recycle gas into the ammonia synthesis reactor (see page 7, last para). The reference does not teach use of a circulator for performing this step. Iod was used to explain that circulation of the loop is created by a compressor, which is also referred to as a circulator (page 8, last para.).
As to (vii), Johanning does disclose an ammonia synthesis loop. It is respectfully argued that the position taken in the arguments at (vii) do not effectively argue that Johanning does not disclose this feature. Moreover, Claim 17, line 7 state “where said ammonia synthesis loop includes” and all the features were addressed. Therefore, by having this features, Johanning does disclose an ammonia synthesis loop.
As to (viii), page 9 of the previous office action states that Lee discloses operating the ammonia synthesis loop at full load.
As to (ix), it was explained on page 5 of the prior rejection that “Johanning describes a method for producing ammonia (para. 1). The method describes operating the plant at either full or partial load mode (paragraph 22 or para. 23)”. As to the make-up synthesis s gas being less than a nominal flow, this was disclosed in the office action as follows:
In the method of Benner, their process feeds an entering gas stream made up of synthesis gas and then fed into a compressor (col. 3, lines 9-11). The ammonia synthesis is manufactured in an ammonia synthesis loop (col. 1, lines 58-61). Benner explains in the background that a stoichiometric ratio of H to N is operated at about 3 in the prior art (col. 1, lines 14-16), but that their system incorporates a recycled gas that is fed as part of the entering stream over the ammonia synthesis gas (col. 1, lines 60-63). The catalyst used can produce ammonia at ratio of less than stoichiometric (col. 2, lines 1-11). The entering gas is then adjusted to lower than stoichiometric (col. 2, lines 18-22). This saves power (col. 2, lines 28-30).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to control the flow of the entering synthesis gas to below the stoichiometric levels, as taught by Benner for use with the process of Johanning because Johanning explains that is lower the power consumption of the system.
Therefore the arguments are not persuasive.
Next, the remarks argue the following:
According to paragraph [0032] of Johanning, the plant appears to be operated according to four alternative ways, i.e., case I, case II, case III, case IV, with these cases being shown in Figs. 1-4 of Johanning, respectively. Fig. 1 of Johanning appears to be the only embodiment wherein the ammonia plant (according to paragraph [0129] of Johanning) can be operated at full load (“Volllast-Modus” in German) or at partial load (“Tei/last-Modus”), due to the presence of the dotted lines, and hence the only embodiment that is pertinent for present claim 17.
Applicant respectfully submits that this limitation in the disclosures of Johanning has not been properly understood by the PTO. For example, the PTO asserts “when the system is operating under a partial load, Johanning describes this a case I (para. 45). When the system 1s operated under full mode, Johanning shows a few options, which is described as case II, case II or case IV.” Office Action, p. 6, Il. 8-11. Applicant respectfully notes that cases II-IV cannot work under partial load because 100% of the syngas is processed to feed the ammonia reactor (no dotted line), as confirmed by paragraphs [0138] and [0145] of Johanning mentioning only production of ammonia (“nur Ammoniak”).
The remarks are respectfully not persuasive. Paragraph 45 and 48 of the Johanning reference explains that Case I, II and III can be operated at either full or partial load (see paragraph 48 “this means that in all four cases the ammonia plant is operated at full or partial load”. Therefore, according to Johanning, all the embodiments in the figures can be operated under either condition.
Next, the remarks argue the following:
Furthermore, following the reasoning present in the last paragraph of p. 6 of the Office action, which assumes that Fig. 2 of Johanning corresponds to the full load condition with all the synthesis gas is sent to the ammonia synthesis reactor, Applicant notes that in such figure the loop is not anymore present because there is no piping connecting the compressor (4), the stripper (7), the wash column (5), the methanator (10), and no piping connecting the liquid ammonia (12) back to the wash column (5) so as close such loop. The embodiment of Fig. 2 shows just a once-through ammonia synthesis process with absolutely no loop.
In view of the above, claim 17 distinguishes Johanning due to features (1i)-(ix).
These remarks are respectfully not persuasive. The last paragraph of page 6 of the office action describes Johanning in both situations: partial and full loads. The argument that there is not loop is unclear. The figures themselves show a loop/ return of the stream. Also, Claim 17 states that a loop is present if the other features described in Claim 17 after line 7, which are disclosed by the references cited and explained in the office action.
Next, the remarks argue the following:
The PTO has not demonstrated the remaining cited references cure the deficiencies of Johanning. The PTO asserts that Lee would remedy the defficiencies noted in Johanning with respect to the by-pass stream, feature (iv.b), and to another feature linked to a “balance between the inlet and the outlet compounds.” Office Action, p. 6-7 and 9-10. Applicant respectfully submits that this alleged disclosure does not appear to be relevant to any of items (1)-(v). Applicant further notes that the citation of Lee is erroneous: US Pat.: 5484584 (“Wallace”) has the title “7herapeutic and diagnostic use of modified polymeric microcapsules” so that at least the deficiency (iv.b) cannot be cured by Lee.
As to the Lee reference, the Office appreciates Applicant pointing out this typographical error. In the future, Applicant is invited to contact the PTO with any concerns of typographical errors prior to the formal submission of a response. The correct Application number has been amended as is: 5484582.
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.
Claim(s) 17, 21, 22, 23 is/are rejected under 35 U.S.C. 103 as being unpatentable over Johanning (WO 2018/091410) and in view of Benner (U.S. Pat.: 4568532) and in view of Maxwell “Ammonia Synthesis”, attached, and in view of Iob (WO 2011/051079) and in view of Lee (US Pat.: 5484582).
The Examiner has provided a machine translation of the foreign references cited. The citation of the prior art in this rejection refers to the machine translation.
Johanning describes a method for producing ammonia (para. 1). The method describes operating the plant at either full or partial load mode (paragraph 22 or para. 23). In this embodiment, a raw synthesis gas goes into a reformer (1) (para. 171 or para. 130). This can be considered to meet the feature of Claim 1 describing “producing an ammonia make-up synthesis gas in a front-end”, where the “front-end” is considered the front portion of the device of Figure 1. The raw synthesis gas then passes through a compressor (4). The stream is then sent to a stripper (7) and into a wash column (5) (Fig. 1). Some of the stream from the wash column is fed into an ammonia synthesis reactor (10, then to 11, then to 12). This can be considered an ammonia synthesis loop of Claim 1. The loop includes reactor 11. Reactor 11 is described as the ammonia synthesis reactor (see para. 176 and 135). Johanning does not specifically state that the ammonia synthesis reactor uses catalysts.The ammonia synthesis reactor (11) can be considered equivalent to the converter where ammonia is synthesized of Claim 1.
The reference describes use of a compressor that helps feed make-up synthesis gas to the loop, but does not describe a circulator, which is a compressor configured to maintain circulation in the ammonia synthesis loop.
Downstream from the ammonia synthesis reactor (11) is a liquid ammonia device (12). The reference does not state that the liquid ammonia device 12 is a condenser or that there is a separator used to separate liquid ammonia from the gaseous stream.
The system has a recycle line, but not one that feeds from the separator section to the suction of the circulator.
As to the operation, Johanning explains that their process is useable for separate startups and separate operation of two subsystems, where the operation can be in partial load (para. 129 and para. 20, 23). This is shown in the different figures. For example, when the system is operating under a partial load, Johanning describes this a case I (para. 45). When the system is operated under full mode, Johanning shows a few options, which is described as case II, case III or case IV (para. 46). The optional return line from 12 to 5 (Fig. 1) or (from 15 to 5 in Fig. 3 or 11 to 5 in Fig. 4) can be considered a recycle line.
As to the load conditions, Johanning does not teach that the make-up synthesis gas is less than a nominal flow. However, in Figure 1, the partial load conditions different the conditions of the other full load conditions (Fig. 2), where the dotted lines indicate an alternative operation (see para. 170 or para. 129), but in the full load condition, all the synthesis gas is sent to the ammonia synthesis reactor (11) (para. 180, 138). Since the process does not divide the gas into a bypass loop (such as in Fig. 1), it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the full amount of make-up gas can be considered a “nominal amount”. Nonetheless, this feature is taught by Lee below.
When operated under partial load, a bypass stream may come from 11 (converter) at a point upstream of the converter, which can be considered a bypass stream (see Fig. 4, 11 bypass stream back to 5).
Johanning does not teach reintroducing the bypass stream at the suction side of the circulator.
As to the catalyst feature and the controlling the flow rate of ammonia make-up gas from the front end to one that is smaller than a nominal flow rate, Benner teaches in the background field that commercial production of ammonia synthesis is typically performed over catalyst bed(s) (col. 1, lines 22-24) that enable conversion of the gas into ammonia at targeted concentrations (col. 1, lines 37-39).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to include catalysts in the ammonia synthesis reactor of Johanning, as taught by Benner because it is conventional in the art and can be employed to enable conversion of the entering gases into ammonia at targeted concentrations.
In the method of Benner, their process feeds an entering gas stream made up of synthesis gas and then fed into a compressor (col. 3, lines 9-11). The ammonia synthesis is manufactured in an ammonia synthesis loop (col. 1, lines 58-61). Benner explains in the background that a stoichiometric ratio of H to N is operated at about 3 in the prior art (col. 1, lines 14-16), but that their system incorporates a recycled gas that is fed as part of the entering stream over the ammonia synthesis gas (col. 1, lines 60-63). The catalyst used can produce ammonia at ratio of less than stoichiometric (col. 2, lines 1-11). The entering gas is then adjusted to lower than stoichiometric (col. 2, lines 18-22). This saves power (col. 2, lines 28-30).
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to control the flow of the entering synthesis gas to below the stoichiometric levels, as taught by Benner for use with the process of Johanning because Johanning explains that is lower the power consumption of the system.
As to the feature of using a condenser in the liquid ammonia generation step (12) of Johanning, Maxwell describes the process for ammonia synthesis (title). The background describes the standard process of making ammonia (Intro, para. 1-2). In this process, Maxwell explains that after the feed gas leaves the ammonia synthesis converter, ammonia is condensed by cooling and removed, which results in the highest ammonia concentration for condensation (see page 1, para. 2). The device used to cool the ammonia can be considered a condenser.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employs a condenser, as taught by Maxwell in the liquid ammonia generation step of the ammonia synthesis loop of Johanning because this is known to result in the highest ammonia concentration.
Johanning describes use of a compressor that helps feed make-up synthesis gas to the loop, but does not describe a circulator, which is a compressor configured to maintain circulation in the ammonia synthesis loop.
Iob describes a plant for the synthesis of ammonia (page 7, line 5) that includes a front-end syngas flow (pg 7, line 9), followed by a compression section 130 (pg 7, line 10), which then feeds to a loop (pg. 7, lines 10-11). The loop includes a catalytic reactor, a gas cooler and a liquid separator to produce liquid ammonia (pg. 7, lines 12-15). The circulation in the loop 106 is created by a compressor, which is also referred to as a circulator (pg. 7, lines 15-16).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a compressor in the synthesis loop, as taught by Iob for use in the synthesis loop of Johanning because compressors circulate the reactants in the synthesis loop.
As to the recycle line being from the separation section to the suction of the circulator, Iob teaches that after the separation section (150) there is a stream 16, which is recycled at the suction of the circulator 140 (page 9, lines 5-6, 15-17). By feeding the recycle line to the suction of the circulator, Iob explains that it minimizes the energy requirement for the compression step (page 9, lines 16-17). The stream 16 can be considered part of the separation section.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to feed the recycle line from the separation section to the suction of the circulator, as taught by Iob for use with the recycle line of Johanning because it minimizes the energy requirement for the compression step.
As to the condition of the ammonia synthesis loop when operated at full load conditions, where there is a nominal flow rate of ammonia make0up gas transferred from the front end to the synthesis loop, this feature is taught by Lee.
Lee describes a process for the ammonia production (abstract). The reference explains in the background that it is generally known in the prior art to feed a synthesis gas to an ammonia-making synthesis loop (col. 1, lines 14-18), which Lee maintains in their process of making ammonia (see Fig. 1). Lee explains in their standard process that the rate of raw makeup stream is about equal to the rate of ammonia production in a continuous ammonia synthesis loop (col. 4, lines 19-22).
Therefore, since Johhanning describes use of either full load or partial load operation, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that during full load the amount of make up stream (syn gas) entering in the loop is about equal to the rate of ammonia produced in the ammonia synthesis loop, as taught by Lee because this is known as standard means of maintaining a continuous reaction. The balanced between the inlet and the outlet compounds can be considered a nominal flow or a standard amount.
As to Claims 21, 22 and 23, Johanning teaches use of a compressor (4) which operates 200-350 bar (para. 63). The reference does not state that this is a nominal flow or what that is in relation to the nominal flow. However, the specification gives examples of a nominal pressure range, which can be from 226 bar (example 1). A prima facie case of obviousness exists where the claimed ranges and prior art ranges overlap or are close enough that one skilled in the art would have expected them to have the same properties. See MPEP 2144.05 I.”
Claim(s) 19, 20, 24 is/are rejected under 35 U.S.C. 103 as being unpatentable over Johanning, Benner, Maxwell, Iob and Lee as applied to claim 17 above, and further in view of Kudrjashov (RU 2306590).
The references do not describe use of a temperature sensor across the converter and adjusting the gas in the bypass stream as a result.
Kudrjashov describes a digital multivariable system for controlling ammonia synthesis (title) for use in the automatic control of temperature in ammonia synthesis (“description”, para. 2) . This system uses sensors in the circulating gas, a temperature controller and sensors in all the catalyst layers and valves on a bypass flow (page 2, lines 8-13). Additionally, the system contains sensors used for measuring the concentration of ammonia and are connected by their inputs to the regulator output temperature in the catalysts which are associated with temperature controllers and a valve on the bypass stream (page 2, lines 10-22). The temperature sensors go across catalysts I-IV layers (page 2, para. 6). Since there are various temperature sensors across various catalysts, this can be considered to meet the feature “detecting the difference of temperature across the converter” because the temperature sensors would inherently detect difference in temperature across the converters since these temperature sensors are spread across the catalysts. Also, since there is a temperature sensor towards an inlet and a temperature sensor towards the outlet, this meets the features of “by detecting the difference between the temperature of the gas feed entering the converter and the temperature of an ammonia-containing product withdrawn from the converter” of Claim 19.
The system includes a valve on the bypass stream associated with a control system, which is also associated with the temperature sensors and temperature controller (page 2, lines 8-12).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the temperature sensors across the catalysts to adjust the valve in the bypass stream, as taught by Kudrjashov for use with the ammonia synthesis of Johanning, Benner, Maxwell, Iob and Lee because this is a known way to automatically control the temperature in an ammonia synthesis device.
As to Claim 20, Kudrjashov teaches in the background that “The method controls temperatures in the catalyst beds by changing the supply of circulating gas and bypass flows depending on the flow rate, pressure, temperature and gas composition at the inlet to the synthesis column, gas pressure in the evaporator, set and measured values of the temperature in the layers” (page 1, “description, para. 2”). The invention of Kudrjashov is the same except that it additionally introduces sensors for the concentration of ammonia and inert gases in the circulating gas, temperature regulator outputs (page 2, para. 3).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that to employ sensors to determine the gas composition at the inlet of the synthesis column in order to adjust the bypass flow, as taught by Kudrjashov for use with the process of Johanning, Benner, Maxwell, Iob and Lee because this is a known way to automatically control the temperature in an ammonia synthesis device.
Claim(s) 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over Johanning, Benner, Maxwell, Iob and Lee as applied to claim 17 above, and further in view of Neumann (DE 102007004294).
The references do not describe the features of Claim 26.
Neumann describes a process for producing fuels (abstract). This reference explains that synthesis gas is made using renewable raw materials (page 3, para. 3), which can be used for ammonia synthesis (Claim 15).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ a synthesis gas made using renewable raw materials, as taught by Neumann for use with the ammonia synthesis process of Johanning, Benner, Maxwell, Iob and Lee because it is known to obtain synthesis gas using renewable raw materials for use as feed in an ammonia synthesis process.
Allowable Subject Matter
Claims 18, 25 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is an examiner’s statement of reasons for allowance: Kudrjashov (RU 2306590). Kudrjashov uses temperature sensors in the converter to adjust the bypass flow (see above), but does not use pressure detectors to determine this.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a). A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action. Any inquiry concerning this communication or earlier communications from the examiner should be directed to SHENG HAN DAVIS whose telephone number is (571)270-5823. The examiner can normally be reached 9-5:30. 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, Fung Coris can be reached at 571-270-5713. 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.
/SHENG H DAVIS/Primary Examiner, Art Unit 1732 December 19, 2025
Prosecution Insights