DETAILED ACTION
Response to Amendment
Amendments to claims 1, 9 and 20 are noted.
The claim amendments overcome the rejections under 35 USC 112(b) and (d).
Due to amendments to the claims, the previous prior art rejections are modified herein.
Response to Arguments
Applicant’s arguments, see p. 9, filed 08 July 2026, with respect to the rejection(s) of the claims under 35 USC 103 based upon the combination of Pillai and Pierce have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration based upon amendments to the claims, a new ground(s) of rejection is made in view of newly discovered prior art.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-6, 9-12, 15 and 17-21 are rejected under 35 U.S.C. 103 as being unpatentable over Pillai et al (US 2023/0407187) in view of Pierce (“Calculating FCC heat balance”) and Walsh (US 4,419,328).
Regarding claims 1, 2, 11, 15, 20, Pillai discloses a process for upgrading hydrocarbon feeds in a fluidized catalytic cracking (FCC) system, comprising (see Abstract; Figs. 1-2):
passing a first portion of a heavy hydrocarbon feed to a first FCC reactor and a second portion of the heavy hydrocarbon feed to a second FCC reactor (see [0010]; [0013], where “at least one riser” is configured for heavy feeds, i.e., encompassing two reactors as claimed; [0018]);
passing a first portion of a light hydrocarbon feed to a third FCC reactor and a second portion of the light hydrocarbon feed to a fourth FCC reactor (see [0010]; [0014], where “one or more risers” are configured to crack medium and/or light feeds, i.e., encompassing two reactors as claimed; [0018]);
passing a cracking catalyst from a catalyst withdrawal well (bottom portion of regenerator 112) to the first, second, third, and fourth FCC reactors, where the catalyst withdrawal well is common to the first, second, third, and fourth FCC reactors, and the reactors are operated in parallel (see [0010]; [0012]);
contacting the first portion and the second portion of the heavy hydrocarbon feed with the cracking catalyst in the first and second FCC reactor, respectively, at high severity conditions, where the contacting causes at least a portion of the heavy hydrocarbon feed to undergo catalytic cracking (see [0010]-[0011]);
contacting the first portion and the second portion of the light hydrocarbon feed with the cracking catalyst in the third and fourth FCC reactor, respectively, at high severity conditions, where contacting causes at least a portion of the light hydrocarbon feed to undergo catalytic cracking (see [0010]-[0011]);
separating reaction mixtures from the first, second, third, and fourth FCC reactors to produce an FCC effluent and spent cracking catalyst (see [0010]);
regenerating the spent cracking catalyst in a common regenerator 112 to produce regenerated catalyst (see [0010]);
passing the regenerated catalyst back to the catalyst withdrawal well (see [0012]);
determining a heat balance requirement of the first, second, third, and fourth FCC reactors (see [0012]); and
controlling a flow rate of the cracking catalyst from the catalyst withdrawal well to the first, second, third, and fourth reactors, based on the heat balance requirements of each of the reactors (see [0012]).
Heavy feeds include reduced crudes, atmospheric tower bottoms, and vacuum tower bottoms (see [0013]), all of which have API gravities which are within or overlapping the claimed range. Light feeds include naphtha (see [0014]), which has an API gravity within or overlapping the claimed range.
Operating conditions within the riser reactors include a temperature above 500°C, a catalyst to oil ratio of greater than 5:1, and a residence time of 1.5-2.5 or 1.7-3.5 seconds (see Table 1), within or overlapping the claimed operating conditions and within the scope of “high severity” conditions.
Pillai does not explicitly disclose wherein controlling the flow rate of catalyst comprises: (1) passing a flue gas exiting the regenerator through an in-line gas analyzer; (2) analyzing a flow rate and amount of carbon monoxide and carbon dioxide in the flue gas; and (3) calculating an amount of coke removed from the spent catalyst from the amount of CO and CO2 in the flue gas and the flow rate of the flue gas.
Regarding (2) and (3), Pierce discloses a step-by-step method for calculating the heat balance of an FCC system, which includes analyzing a flow rate of flue gas exiting the regenerator and the concentrations of CO and CO2 in the flue gas to calculate an amount of coke removed from the spent catalyst. Based on the information gleaned from the calculations, catalyst circulation rates may be determined (see Abstract).
It would have been obvious to a person of ordinary skill in the art at the time of filing the instant claimed invention to utilize the FCC heat balance calculation methods taught in Pierce for enhanced control of the FCC process of Pillai, i.e., in order to provide enhanced regulation of catalyst circulation to the various reactors.
Regarding (1), while Pierce discloses the above steps for calculating the heat balance of an FCC system, the reference fails to disclose implementation as claimed, including passing the flue gas exiting the regenerator through an in-line gas analyzer.
Walsh discloses passing flue gas exiting regeneration of an FCC catalyst through an in-line gas analyzer 31 to analyze the concentration of CO and CO2 therein, thus providing information for control of the regeneration process (see Fig. 1; col. 3, lines 50-53; col. 4, lines 25-34)
Accordingly, the prior art shows that CO and CO2 concentrations in regeneration flue gas may be used to determine catalyst recirculation rate for the purpose of controlling FCC heat balance, as is disclosed in Pierce, and that in-line analyzers provide real time information regarding concentrations of CO and CO2 in a regenerator flue gas, as is disclosed in Walsh. In applying the FCC heat balance technique of Pierce to Pillai’s FCC process operation, a person of ordinary skill in the art would find it obvious to implement an in-line gas analyzer on the regenerator flue gas line, as suggested by Walsh, in order to continuously gather the necessary data to control FCC heat balance in real time.
Regarding claim 3, Pillai discloses wherein the common regenerator is operated without supplemental fuel or catalyst coolers (see throughout, in particular [0012], no disclosure that either are required and that no external heat source or fuel is needed in balanced operation).
Regarding claim 4, Pillai discloses wherein separating the reaction mixtures of the first, second, third, and fourth reactors comprises (see Fig. 1):
passing the reaction mixtures from the first, second, third, and fourth reactors to a common fluid-solid separator (disengaging section 108) (see [0010]); and
separating the reaction mixtures in the common fluid-solid separator to produce the FCC effluent and the spent cracking catalyst (see [0010]).
Regarding claims 5 and 6, Pillai discloses wherein controlling the flow rate comprises operating a first valve disposed between the catalyst withdrawal well and the first FCC reactor, a second valve disposed between the catalyst withdrawal well and the second FCC reactor, a third valve disposed between the catalyst withdrawal well and the third reactor, and a fourth valve disposed between the catalyst withdrawal well and the fourth reactor (see Fig. 1; [0012]).
Regarding claim 9, Pillai in view of Pierce discloses the technique for determining an amount of coke on the spent cracking catalyst as discussed above. In addition, Pillai discloses comparing the heat balance requirements of each of the risers and operating a first valve, a second valve, a third valve, and a fourth valve to adjust a catalyst to oil ratio of the first, second, third and fourth reactors, respectively, wherein adjusting the catalyst to oil ratio changes a reactor outlet temperature of the reactor(s) (see [0006]; [0012]).
Regarding claim 10, Pillai discloses wherein a cracking temperature of the first and second FCC reactors is within 100°C of a cracking temperature of the third and fourth FCC reactors (see Table 1).
Regarding claim 12, Pillai discloses wherein regenerating the spent catalyst comprises combusting coke deposited on the spent cracking catalyst (see [0012]).
Regarding claims 17 and 18, Pillai does not explicitly disclose the conversion rates of the feeds to coke in the reactors. However, the office notes that Pillai discloses control of conversion conditions (see [0011]-[0012]), including that heat balance is maintained within the system by heat generated during the exothermic regeneration reaction. In other words, a certain amount of coke on the catalyst is required in order to maintain the heat balance. A person of ordinary skill in the art, when considering the teachings and suggestions of Pillai, would determine the optimum operating and conversion conditions which facilitates maintaining the heat balance within the system, including conversion of the feeds to coke. Absent a showing of criticality or unexpected results, the claimed conversion to coke is not considered to patentably distinguish the instant claims over the cited prior art.
Regarding claim 19, Pillai discloses wherein no coke precursors are introduced to the hydrocarbon feeds (see [0012], an optional embodiment of adding a coke forming agent is disclosed; however, by being optional, the disclosure also encompasses no addition of such materials to the process).
Regarding claim 21, Pillai does not explicitly disclose the pressure at which the reactors are operated, but does suggest controlling pressure in order to provide tailored conversion reactions based on the nature of the feedstocks (see [0011]). Determining the optimum pressures at which to operate the reactors would have been obvious to a person of ordinary skill in the art and achieved by routine experimentation. Absent a showing of criticality or unexpected results, the claimed pressure is not considered to patentably distinguish the instant claim over the cited prior art.
Claims 13 and 14 are rejected under 35 U.S.C. 103 as being unpatentable over Pillai in view of Pierce and Walsh, as applied to claim 1, in further view of Akah et al (US 2022/0098493).
Regarding claims 13 and 14, Pillai does not explicitly disclose wherein the heavy hydrocarbon feed is a whole crude oil or the light hydrocarbon feed comprises a light crude oil, an extra light crude oil, or a gas condensate.
However, such feed materials are known in the art to benefit from catalytic cracking to produce valuable conversion products, including in parallel operation FCC reactor systems (see Akah: [0028]; [0045]).
It would have been obvious to a person of ordinary skill in the art to select a whole crude as a heavy hydrocarbon feed and a gas condensate as a light feed to use as the feed materials in the process of Pillai, where Akah establishes that such feed materials benefit from FCC reactions to produce valuable products including olefins.
Claim 16 is rejected under 35 U.S.C. 103 as being unpatentable over Pillai in view of Pierce and Walsh, as applied to claim 1, in further view of Abba et al (WO 2013/142563).
Regarding claim 16, Pillai does not disclose wherein the either or both of the feeds is a hydrotreated feed.
Abba discloses integrating hydroprocessing with FCC, wherein the feed is hydroprocessed prior to FCC in order to reduce contaminants therein (see Abstract).
It would have been obvious to a person of ordinary skill in the art at the time of filing the instant claimed invention to modify the process of Pillai to use hydrotreated feed streams, as suggested by Abba, in order to provide feeds to the FCC system which have a reduced concentration of contaminants.
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Pillai in view of Pierce and Walsh, as applied to claim 1, in further view of Dean et al (US 2013/0137909).
Regarding claim 22, Pillai does not disclose wherein the reactors are operated in a down-flow configuration.
Dean is directed to FCC in a downflow reactor. Dean discloses that downflow reactors utilize gravity to decrease residence times in the reaction zone and can circulate higher quantities of hot regenerated catalyst compared to riser reactors, thereby permitting higher catalyst to oil ratios. They also have the additional advantages due to the length of the reactor zone compared to existing riser reactors, which are more than double or triple the length of downflow reactors (see [0062]-[0063]).
It would have been obvious to a person of ordinary skill in the art at the time of filing the instant claimed invention to modify the process of Pillai by utilizing downflow reactors, as suggested by Dean, which allow for higher catalyst to oil ratios and decreased residence times in comparison to riser reactors.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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 RENEE ROBINSON whose telephone number is (571)270-7371. The examiner can normally be reached Monday - Thursday 8:00a-5:00p and Friday 8:00a-2:00p.
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/Renee Robinson/Primary Examiner, Art Unit 1772
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