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 .
Status of the Claims
The status of the claims as filed in the reply dated 6/17/2026 are as follows:
Claims 1, 3, 5-10, and 12 -20 are amended,
Claims 1-20 are currently pending.
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.
Claim(s) 1-7, 9-11, and 17-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Apte et al. (U.S. Patent Publication No. 2018/0179960, “Apte”, previously cited) in view of Chahroudi et al. (U.S. Patent No. 4,259,401, “Chahroudi”, previously cited).
Regarding claim 1, Apte discloses a system for storing energy (fig 22), the system comprising:
one or more thermally insulated vessels (8, 9, ¶0098);
a phase change material (PCM)(CTS medium, ¶0090, ¶0065) disposed in the thermally insulated vessel(s);
a refrigerant circuit (1, 2, 3, 4) configured to circulate a refrigerant fluid in thermal communication with the PCM such that the PCM absorbs thermal energy from the refrigerant fluid at a point in a refrigeration cycle of the process (at heat exchanger 4 during the discharge mode, ¶0082);
where the PCM is configured to transition from an initial state to a higher enthalpy state at a transition temperature that is below a lowermost working temperature at the point in the refrigeration cycle (see ¶0065); and
where the PCM requires at least 10 MWh to transition from the initial state to the higher enthalpy state (see ¶0071).
The limitation of “for refrigeration in a chemical separation process of a chemical plant“ is considered an intended use limitation. “[A]pparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co.v.Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990). As such, as a general rule, the manner of operating a device does not differentiate apparatus claims from the prior art. On the other hand, patent claims can distinguish from the prior art by claiming functional features which are a result of structural differences. A claim term is functional when it recites a feature “by what it does rather than by what it is” (e.g., as evidenced by its specific structure or specific ingredients). In re Swinehart, 439 F.2d 210, 212, 169 USPQ 226, 229 (CCPA 1971).
However, Apte does not explicitly disclose wherein the PCM is in the form of PCM slurry. Chahroudi, however, discloses a system wherein the PCM is in the form of a slurry (col 13, lines 26-48). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Apte to have the PCM be a slurry such as taught by Chahroudi in order to optimize the heat storage for a given application.
Regarding claim 2, the combination of Apte and Chahroudi discloses all previous claim limitations. Apte, as modified, further discloses where the refrigerant circuit is part of a refrigeration system that comprises a compressor (1) configured to compress the refrigerant fluid such that the refrigerant fluid can be circulated to receive thermal energy in the process (¶0043).
Regarding claim 3, the combination of Apte and Chahroudi discloses all previous claim limitations. Apte, as modified, further discloses where the refrigerant fluid is a first refrigerant fluid and the refrigerant circuit is a first refrigerant circuit (see annotated fig 22 below), and the system further comprises: a PCM slurry refrigeration circuit comprising a compressor (see annotated fig 22 below).
PNG
media_image1.png
548
718
media_image1.png
Greyscale
However, Apte, in this embodiment, does not explicitly disclose a second refrigerant circuit configured to circulate a second refrigerant fluid in thermal communication with a the PCM such that the second refrigerant fluid absorbs thermal energy from the PCM slurry. However, in another embodiment (fig 31), Apte discloses a second refrigerant circuit (see annotated fig 31 below, ¶0204) in thermal communication with a the PCM slurry such that the second refrigerant fluid absorbs thermal energy from the PCM slurry (Hexane). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Apte to provide the second refrigerant circuit in the embodiment of figure 22 in order to cool the PCM before the discharging phase.
PNG
media_image2.png
643
776
media_image2.png
Greyscale
Regarding claim 4, Apte, as modified, discloses all previous claim limitations. Apte further discloses where the compressor is electric (¶0070, in the case of additional power electronics/motor).
Regarding claim 5, the combination of Apte and Chahroudi discloses all previous claim limitations. Apte, as modified, further discloses where the PCM slurry has a phase transition below a temperature range from −170° C to 40° C (in the case of a cryogenic liquid being used, see ¶0064).
Regarding claim 6, the combination of Apte and Chahroudi discloses all previous claim limitations. Apte, as modified, further discloses where the one or more thermally insulated vessels comprises a first thermally insulated vessel(s) and the PCM slurry is a first PCM (22) slurry, and the system further comprises: one or more second thermally insulated vessels (6, 7); a second phase change material (PCM)(HTS medium, ¶0090, ¶0065) disposed in the second thermally insulated vessel(s), the second PCM slurry configured to transition from an initial state to a higher enthalpy state at a second transition temperature that is above the transition temperature of the first PCM (¶0090); where the second PCM slurry requires at least 10 MWh to transition from the initial state to the higher enthalpy state (see ¶0071).
Regarding claim 7, the combination of Apte and Chahroudi discloses all previous claim limitations. Apte, as modified, further discloses further discloses where the PCM slurry comprises an organic chemical (propane, ¶0064).
Regarding claim 9, the combination of Apte and Chahroudi discloses all previous claim limitations. However, Apte does not explicitly disclose where the PCM is in a form selected from the group of forms consisting of: a slurry in which the PCM is directly suspended in a liquid within the insulated vessel(s); an encapsulated slurry in which the PCM is encapsulated in casings that are suspended in a liquid within the insulated vessel(s); and a plurality of containers each containing a portion of the slurry and including at least one heat-transfer surface configured to permit thermal communication with the PCM. Chahroudi, however, discloses a system wherein the PCM is in a form of an encapsulated slurry in which the PCM is encapsulated in casings that are suspended in a liquid (col 13, lines 26-48). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Apte, as modified, to have the PCM be water and sodium chloride such as taught by Chahroudi in order to optimize the heat storage for a given application.
Regarding claim 10, the combination of Apte and Chahroudi discloses all previous claim limitations. Apte, as modified, further discloses where the PCM is in a slurry or encapsulated slurry form (see col 13, lines 26-48 of Chahroudi) and the system is configured to agitate the PCM within the insulated vessel(s) (at least when the PCM moves from vessel 8 to vessel 9).
Regarding claim 11, the combination of Apte and Chahroudi discloses all previous claim limitations. The limitation of “where the process is selected from the group of processes consisting of: a steam cracking process, an ammonia synthesis process, a hydrogen production process, a para-xylene production process, propane dehydrogenation, olefin metathesis, and natural gas processing” is considered an intended use limitation. “[A]pparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co.v.Bausch & Lomb Inc., 909 F.2d 1464, 1469, 15 USPQ2d 1525, 1528 (Fed. Cir. 1990). As such, as a general rule, the manner of operating a device does not differentiate apparatus claims from the prior art. On the other hand, patent claims can distinguish from the prior art by claiming functional features which are a result of structural differences. A claim term is functional when it recites a feature “by what it does rather than by what it is” (e.g., as evidenced by its specific structure or specific ingredients). In re Swinehart, 439 F.2d 210, 212, 169 USPQ 226, 229 (CCPA 1971).
Regarding claim 17, the combination of Apte and Chahroudi discloses all previous claim limitations. Apte, as modified, further discloses wherein the refrigeration system is configured to: receive cooled refrigerant fluid from the refrigeration system; and circulate the cooled refrigerant fluid through the refrigerant circuit such that the refrigerant fluid absorbs thermal energy from the PCM slurry (CTH medium, during the charging mode, ¶0082).
Regarding claim 18, the combination of Apte and Chahroudi discloses all previous claim limitations. Apte, as modified, further discloses wherein the refrigeration system is configured to: receive warmed refrigerant fluid from the process; and circulate the warmed refrigerant fluid through the refrigerant circuit such that the PCM slurry (CTH medium) absorbs thermal energy from the warmed refrigerant fluid (during the charging mode, ¶0082).
Regarding claim 19, the combination of Apte and Chahroudi discloses all previous claim limitations. Apte, as modified, further discloses where the PCM is in a slurry form and directly suspended in a liquid within the insulated vessel(s), a nucleating agent is added to the liquid (see col 13, lines 26-48 of Chahroudi).
Regarding claim 20, the combination of Apte and Chahroudi discloses all previous claim limitations. Apte, as modified, further discloses where the first PCM slurry and the second PCM slurry are configured to together require at least 100 MWh to transition from the initial state to the higher enthalpy state (see ¶0071).
Claim(s) 8 is/are rejected under 35 U.S.C. 103 as being unpatentable over Apte and Chahroudi as applied to claim 7 above, and further in view of Kilmer et al. (U.S. Patent Publication No. 2018/0086534, “Kilmer”, previously cited).
Regarding claim 8 the combination of Apte and Chahroudi discloses all previous claim limitations. However, Apte does not explicitly disclose wherein the PCM comprises a water-salt mixture that comprises one or more components selected from the group of components consisting of: calcium dichloride; calcium dichloride; lithium chloride; magnesium chloride; zinc chloride; hydrogen chloride; lithium sulfate; sodium chloride; potassium chloride; aluminum nitrate; combinations of any two or more of the foregoing components. Kilmer, however, discloses a system (fig 1) wherein a PCM slurry comprises a water-salt mixture comprising sodium chloride (¶0021). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Apte, as modified, to have the PCM slurry be water and sodium chloride such as taught by Kilmer in order to optimize the heat storage for a given application.
Claim(s) 12-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Apte et al. (U.S. Patent Publication No. 2018/0179960, “Apte”, previously cited) in view of Greene (U.S. Patent Publication No. 2012/0314829, previously cited) and in further view of Chahroudi et al. (U.S. Patent No. 4,259,401, “Chahroudi”, previously cited).
Regarding claim 12, Apte discloses a method of storing energy (fig 22), the method comprising: during a discharge cycle, circulating a refrigerant fluid in thermal communication with a phase-change material (PCM)(CTH) such that the PCM absorbs thermal energy from the refrigerant fluid at a point in a refrigeration cycle of the process (¶0082); where the PCM is configured to transition from an initial state to a higher enthalpy state at a transition temperature that is below a lowermost working temperature of the refrigerant at the point in the refrigeration cycle (at heat exchanger 4); and where the PCM absorbs at least 10 MWh of energy from the refrigerant fluid during a 24-hour period (¶0072).
However, Apte does not explicitly disclose the method of storing energy is for refrigeration in a chemical separation process of a chemical plant. Greene, however, discloses a method for storing energy for refrigeration in a chemical separation process of a chemical plant (“hydrogen product”, see ¶0002-0003). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Apte to provide the system for refrigeration in a chemical separation process of a chemical plant in order to aid in the process.
However, Apte does not explicitly disclose wherein the PCM is in the form of PCM slurry. Chahroudi, however, discloses a system wherein the PCM is in the form of a slurry (col 13, lines 26-48). It would have been obvious to a person of ordinary skill in the art before the effective filing date of the claimed invention for Apte to have the PCM be a slurry such as taught by Chahroudi in order to optimize the heat storage for a given application.
Regarding claim 13, the combination of Apte, Greene, and Chahroudi discloses all previous claim limitations. Apte further discloses where a 24-hour period includes one or more discharge cycles lasting a total 2-22 hours, and one or more recharge cycles lasting a total of 2-22 hours (¶0072).
Regarding claim 14, the combination of Apte, Greene, and Chahroudi discloses all previous claim limitations. Apte further discloses where the lengths of the recharge and discharge cycles are adjusted or selected based on a methodology selected from the group of methodologies consisting of: in response to a request from a power grid operator to reduce consumption of electric power (such as during peaking power plants, ¶0071)
Regarding claim 15, the combination of Apte, Greene, and Chahroudi discloses all previous claim limitations. Apte, as modified, further discloses during the recharge cycle, operating a compressor (1) to simultaneously cool the refrigerant fluid that is circulated in thermal communication with the PCM slurry (CTH medium) and refrigerant fluid. Apte does not explicitly disclose that is used in a propylene or ethylene refrigeration system for the process. However, the Examiner takes Official notice that the use of propylene or ethylene is old and well known in the art of refrigeration and it would have been obvious to for Apte, as modified, to have the refrigeration use either propylene or ethylene.
Regarding claim 16, the combination of Apte, Greene, and Chahroudi discloses all previous claim limitations. Apte further discloses adjusting the rate at which the PCM slurry is absorbing thermal energy from the refrigerant fluid (see ¶0173).
Response to Arguments
Applicant's arguments filed 6/17/2026 have been fully considered but they are not persuasive.
Applicant argues (pages 7-10) that the combination of Apte and Chahroudi is improper as the are not in the same field of endeavor and further there is nothing to suggest that the PCM slurry of Chahroudi could be scaled up to meet the size of Apte. The Examiner respectfully disagrees; both Apte and Chahroudi are designed to store heat via a PCM and thus are analogues prior art. Further, a person of ordinary skill in the art would understand that a PCM slurry such as taught by Chahroudi could be used in place of the PCM of Apte.
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 HARRY E ARANT whose telephone number is (571)272-1105. The examiner can normally be reached Monday-Friday 10-6 ET.
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, Jianying Atkisson can be reached at (571)270-7740. 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.
/HARRY E ARANT/Primary Examiner, Art Unit 3763
Prosecution Insights