DETAILED ACTION
Status of Application
This action is responsive to national-stage application filed 11/17/2022. The concurrently filed preliminary amendment is acknowledged. Claims 1-16 are currently pending and under examination herein.
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 .
Information Disclosure Statement(s)
The information disclosure statement(s) (IDS) filed on 11/17/2022 and 04/08/2026 are in compliance with the provisions of 37 CFR 1.97, 1.98 and MPEP § 609, and therefore the information referred to therein has been considered as to the merits. Initialed copies of the IDS are included with the mailing/transmittal of this Office action.
Objection – Specification
The disclosure is objected to because of the following informalities:
Referring to paragraph [0009], the phrase “It is to b20” is not understood and appears to be an incomplete sentence that concludes in paragraph [0010]).
Referring to paragraph [0071], the reference to “secondary compressor 62” is incorrect in that “62” should read –20-- (cf., corresponding component as shown in FIG. 3).
Appropriate correction of the specification is required.
Claim Interpretation
With respect to claim 14, the Office is construing the term “hot water” in line 6 to mean water at a temperature high enough to provide an aqueous medium effective in “cleaning a cooling recycle system” as recited in the preamble of the claim and consistent with the supporting disclosure; see paragraph [0072] of as-filed specification.
Claim Rejections – 35 U.S.C. 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-16 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Regarding Claims 1, 13, and 16, the use of “about” as a modifier of the endpoint values of ranges for pressure when depressurizing the reactor component (or reactor) and when introducing purge gas into the reactor component (or reactor), and for concentration of O2 present in the reactor component, creates indefiniteness, since the term "about" has been held to allow some flexibility [see Amgen, Inc. v. Chugai Pharmaceutical Co., 18 USPQ2d 1016, 1030 (Fed. Cir. 1991) and In re Erickson, 145 USPQ 207 (CCPA 1965)] and the specification provides no definition or standard for ascertainment of the intended degree of flexibility or latitude; i.e., the extent to which “about” opens the claims to pressure values and O2 concentrations outside the specified numerical endpoints for these parameters. Clarification at least by way of explanation is required. Dependent claims 2-15 are subsumed in this ground of rejection.
Regarding Claim 3, the claim recites “wherein the reactor component is a primary compressor.” Thus, the claim is drawn to a process for shutting down a primary compressor in a LDPE process. However, when read in light of the supporting disclosure, it is unclear how only the recited step (“closing one pair of upstream lock-out valves and one pair of downstream lock-out valves”) suffices to effectuate the intended shut-down of this reactor component. That is, according to paragraph [0048] and FIG. 1, it is essential that the feed valve in a feed stream to the primary compressor be closed as well. Omission of this essential feature renders the claim incomplete, hence indefinite. Clarification and appropriate correction are required.
Regarding Claim 16, the claim recites “a high pressure separator disposed upstream from the cooling recycle system” (see lines 6-7) but fails to specify the requisite structural connection between these components. Omission of such necessary structural connection renders the claim incomplete, hence indefinite. See MPEP § 2172.01. Clarification and appropriate correction are required.
Pertinent Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Wolfram et al (US 2018/0030160 A1) is cited merely to show analogous art, i.e., art relating to an emergency shutdown program for a high-pressure polymerization process for producing polymeric materials such as LDPE (note ¶¶ [0010]-[0011], [0024]). The cited art does not teach the instant process as claimed.
Potentially Allowable Subject Matter
Claims 1-16, as best understood, are deemed free of the prior art.
The following is a statement of reasons for the indication of allowable subject matter:
Pending claims are deemed to distinguish over the closest prior art to Leung et al (US 2018/0345238 A1), Purging Principles and Practice (American Gas Association (‘AGA’), 2001-01-01, pp. 1-159), Singh (WO 2019/173030 A1), Bell et al (US 2014/0343242 A1) and Bernier et al (US 5453471).
Applicant claims a process for shutting down a reactor component in a LDPE process, comprising:
(I) closing one or more pairs of upstream lock-out valves, each pair of upstream lock-out valves being located in an inlet stream upstream of the reactor component and configured to cease fluid flow into the reactor component through said inlet stream when said pair of upstream lock-out valves is closed;
(II) closing one or more pairs of downstream lock-out valves, each pair of downstream lock-out valves being located in an outlet stream downstream of the reactor component and configured to cease fluid flow out of the reactor component through said outlet stream when said pair of downstream lock-out valves is closed;
(III) depressurizing the reactor component to a pressure greater than about 0 MPag and less than about 1.0 MPag;
(IV) introducing purge gas comprising N₂ into the reactor component through a purge gas inlet at a pressure greater than about 0.5 MPag and less than about 5.0 MPag; and
(V) withdrawing the purge gas from the reactor component through a purge gas outlet,
wherein withdrawing the purge gas comprises depressurizing the reactor component to a pressure greater than about 0 MPag and less than about 1.0 MPag.
(Claim 1; reference notation added)
Applicant also claims a process for shutting down a reactor and a collection vessel in a LDPE process, comprising:
(I’) closing a first pair of in-line valves in a first stream being introduced to a reactor, a second pair of in-line valves in a second stream disposed between a cooling recycle system and a collection vessel for collecting wax, and a third pair of in-line valves in a third stream exiting the collection vessel, wherein a fourth stream exits the reactor and enters a high pressure separator disposed upstream from the cooling recycle system, wherein a first in-line valve and a second in-line valve downstream from the first in-line valve are disposed in the fourth stream, and wherein a fifth stream connects the fourth stream between the first in-line valve and the second in-line valve to the collection vessel;
(II’) closing the second in-line valve in the fourth stream;
(III’) opening a first bleeder valve in a first bleeder stream that connects to the first stream between the first pair of in-line valves, a second bleeder valve in a second bleeder stream that connects to the second stream between the second pair of in-line valves, a third bleeder valve in a third bleeder stream that connects to the third stream between the third pair of in-line valves, and a purge valve in the fifth stream;
(IV’) depressurizing the reactor to a pressure greater than about 0 MPag and less than about 1.0 MPag; and
(V’) introducing purge gas comprising N₂ at a pressure greater than about 0.5 MPag and less than about 5.0 MPag to the reactor.
(Claim 16; reference notation added)
Leung et al discloses a process for producing LDPE in a high-pressure reactor (¶¶ [0001], [0013]). The processing apparatus comprises a hypercompressor which leads to the reactor and at the end of the reactor there is a let-down valve through which the ethylene/polymer mixture leaves the reactor and enters a high-pressure product separator. Leung et al also discloses a process in which the reactor may be shut-down, which requires the reactor to be vented, i.e., depressurized (¶¶ [0034]-[0035]). The reactor and possibly the hypercompressor are isolated and several valves are used for releasing the pressure.
Leung et al fails to disclose isolation of the reactor by closing one or more pairs of upstream lock-out (or in-line) valves, closing one or more pairs of downstream lock-out (or in-line) valves, depressurizing the reactor to a pressure greater than about 0 MPag and less than about 1.0 MPag, and introducing purge gas comprising N₂ into the reactor through a purge gas inlet at a pressure greater than about 0.5 MPag and less than about 5.0 MPag. Accordingly, pending claims are considered to distinguish over Leung et al at least on the basis of features (I) – (IV) or (I’) – (IV’) above.
AGA in section 1.5(b) lists valve closures as one of six methods by which a section of space may be isolated from adjoining facilities or piping. However, in section 1.5(c), AGA notes that when complete shut-off is required, the use of valves already located in the system may not be recommended unless the two valves can be closed and the piping between them either removed or vented. AGA further notes the availability of valves designed with the block and bleed feature, which permits venting the volume between valve seals to atmospheric pressure, as an alternative to double valving. AGA, however, is completely silent concerning isolation of a reactor component by closing one or more pairs of upstream lock-out valves, closing one or more pairs of downstream lock-out valves, depressurizing the reactor component to a pressure greater than about 0 MPag and less than about 1.0 MPag, and introducing purge gas comprising N₂ into the reactor component through a purge gas inlet at a pressure greater than about 0.5 MPag and less than about 5.0 MPag. Accordingly, pending claims are considered to distinguish over AGA at least on the basis of same features (I) – (IV) or (I’) – (IV’).
Singh is directed to methods of preparing a polymerization reactor having a seed bed for reactor startup (¶ [0002]). The disclosed methods generally comprise the steps of injecting an alkyl solution onto the seed bed; soaking the seed bed for at least one hour; determining the ethane concentration in the reactor where soaking the seed bed is continued if ethane concentration is increasing; and commencing reactor startup when ethane concentration has reached an equilibrium. In an aspect the alkyl solution comprises triethylaluminum (TEAL) (¶ [0006]). As part of a polymerization reactor startup procedure, Singh describes venting and pressurizing the reactor with nitrogen (¶¶ [0091]-[0095], [0110]-[0111]). And while low-pressure nitrogen (120 kpag to atmospheric) is used to implement an O2-free reactor during the startup (¶ [0094]), Singh does not contemplate application of such purging conditions during a process of shutting down a reactor component, or a reactor and a collection vessel, in a LDPE process. Furthermore, Singh is completely silent as to claimed features (I)/(II) and (I’) – (III’) above.
Bell et al discloses a polymerization process with, e.g., ethylene as monomer, which comprises the flushing of one or more device elements in case of start-up or shut-down (¶ [0038]). Nitrogen is used as the inert flushing fluid (Example), and the process includes pressure relief valves and withdrawal lines (¶ [0020]). Bell et al also discloses that nitrogen flushing is done at a higher pressure than pressure of the element being flushed (¶ [0029]). Nevertheless, Bell et al is completely silent as to isolating a reactor component, or a reactor and a collection vessel, in a LDPE process by closing one or more pairs of upstream lock-out (or in-line) valves and closing one or more pairs of downstream lock-out (or in-line) valves prior to the flushing operation. Accordingly, pending claims are considered distinguish over Bell et al at least on the basis of features (I)/(II) or (I’)/(II’) above.
Bernier et al discloses a process for producing polymers in a gas phase reactor by continuously introducing a stream of monomer and gas into a polymerization zone while maintaining the temperature within the polymerization zone below the dew point temperature of at least one monomer present in said polymerization zone (Abs.). In a typical mode of operation, Bernier et al describe that product in product discharge tank 46 flows into product surge tank 54. Valve 52 is then closed. The product is purged with inert gas, preferably nitrogen, which enters product surge tank 54 through line 58 and is vented through line 56. Product is then discharged from product surge tank 54 through valve 60 and conveyed through line 20 to storage (col. 7, ll. 59-66). Bernier et al does not contemplate application of such inert gas purging during a process of shutting down a reactor component, or a reactor and a collection vessel, in a LDPE process. Furthermore, Bernier et al is completely silent as to claimed features (I)/(II) and (I’) – (III’) above.
In light of the foregoing discussion, it should be evident as to why the pending claims are allowable in substance over the prior art.
Correspondence
Any inquiry concerning this communication should be directed to Examiner F. M. Teskin whose telephone number is (571) 272-1116. The examiner can normally be reached on Monday through Friday from 9:00 AM - 5:30 PM.
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, Robert Jones, can be reached at (571) 270-7733. The appropriate fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
Information regarding the status of an application may be obtained from Patent Center. Status information for published applications may be obtained from Patent Center. Status information for unpublished applications is available through Patent Center for authorized users only. Should you have questions about access to Patent Center, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative or access to the automated information system, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000.
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) Form at https://www.uspto.gov/patents/uspto-automated- interview-request-air-form.
/FRED M TESKIN/Primary Examiner, Art Unit 1762
/FMTeskin/04-30-26
Prosecution Insights