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 .
Response to Amendment
Amendments to the specification and claim 1 are noted.
The reply overcomes the claim rejection under 35 USC 112(b).
Due to amendments to the claims, the previous prior art rejections are modified herein.
Response to Arguments
Applicant’s arguments with respect to claim 1 have been considered but are moot because the arguments do not apply to the grounds of rejection being used in the current rejection.
In particular, while Applicant argues that Wijnja does not disclose nor provide any motivation or suggestion for a skilled person to sequence pre-heating such that pre-heating is started outside of the cracker furnace before feeding the hydrocarbon feed stream to the convection section for further pre-heating, the office is of the position that the modifying reference, Purola, discloses such an embodiment and provides the motivation for its implementation. See following.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 8 is rejected under 35 U.S.C. 112(d) or pre-AIA 35 U.S.C. 112, 4th paragraph, as being of improper dependent form for failing to further limit the subject matter of the claim upon which it depends, or for failing to include all the limitations of the claim upon which it depends.
Claim 8 specifies that the feed stream is not pre-heated in the convection section before pre-heating the feed stream outside the cracker furnace. The amendments to claim 1, while worded somewhat different, already require this embodiment. Claim 8 therefore fails to further limit the claim upon which it depends.
Applicant may cancel the claim(s), amend the claim(s) to place the claim(s) in proper dependent form, rewrite the claim(s) in independent form, or present a sufficient showing that the dependent claim(s) complies with the statutory requirements.
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 1-8 are rejected under 35 U.S.C. 103 as being unpatentable over Wijnja et al (US 2022/0372377) in view of Purola (US 2021/0171836).
Regarding claims 1, 3, 7 and 8, Wijnja discloses a process for producing olefins from a feed stream containing hydrocarbons by pyrolytic cracking of the hydrocarbons in a cracker furnace 40, comprising (see Abstract; Fig. 1; [0041]-[0042]):
pre-heating the feed stream outside of the cracker furnace (in TLE 35);
feeding the pre-heated feed stream to a tube 26 in a convection section 20 of the furnace;
further pre-heating the pre-heated feed stream in the convection section;
feeding the further pre-heated feed stream to a tube 11 in a radiant section 10 of the cracker furnace;
pre-heating an oxygen containing stream (combustion air 6 in preheater 27 of the convection section);
contacting the pre-heated oxygen containing stream with a fuel gas 5 in a burner 12 in the radiant section; and
pyrolytic cracking the feed stream in the radiant section resulting in an effluent containing olefins.
Wijnja discloses initial steps of pre-heating the feedstock prior to entry into the first high temperature coil (see [0017]-[0018]), but does not explicitly disclose wherein the pre-heating outside the cracker furnace is performed before feeding the feed stream to a tube in the convection section of the cracker furnace for the first time (or wherein the feed stream is not preheated in the convection section before pre-heating outside cracker furnace), as claimed.
Purola, like Wijnja, is directed to pyrolysis and heat integration thereof (see Abstract; [0039]). In particular, Purola discloses pre-heating the feed to a furnace inlet temperature in a heat exchanger prior to passing into the convection section of the furnace because it enables reduction of flue gas stack temperature, which, in turn, accounts for improved thermal efficiency in the furnace. Streams used for pre-heating include low pressure steam (see [0122]; [0154]).
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 Wijnja by pre-heating the feedstock by exchange with low pressure steam prior to entry into the convection section, as suggested by Purola, in order to allow for reduction of flue gas stack temperature and improve thermal efficiency of the furnace.
Regarding claim 2, Wijnja discloses wherein the feed stream containing hydrocarbons is pre-heated outside the cracker furnace to a temperature up to 550°C, e.g., around 555°C (see [0021], outlet temperature on the cold side of the TLE is kept to around 550°C; [0043]), overlapping the claimed range.
Regarding claim 4, Wijnja discloses two TLEs 35, 36 arranged in series, where effluent from the radiant section passes through the first and then the second in series. In the first TLE, the effluent exchanges heat with the feed stream and, in the second, the effluent exchanges heat with utility water to provide pressurized steam (see [0041]). Thus, while Wijnja discloses the same types of heat exchange with the effluent, the order is reversed. Nevertheless, selection of any order of performing process steps is prima facie obvious in the absence of new or unexpected results. In re Burhans, 154 F.2d 690, 69 USPQ 330 (CCPA 1946).
Regarding claim 5, Wijnja discloses the process further comprising (see [0041]):
pre-heating utility water 3 outside the cracker furnace (in steam drum 33); and
generating pressurized steam from the pre-heated utility water through indirect heat exchange with effluent from the radiant section (in TLE 36).
Regarding claim 6, Wijnja does not explicitly disclose the temperature to which the oxygen containing stream is pre-heated. However, the reference discloses that the pre-heating step functions to raise the adiabatic flame temperature and make the firebox more efficient (see [0042]). A person of ordinary skill in the art would optimize, by routine experimentation, the temperature to which the oxygen containing stream is preheated which is associated with efficient operation of the firebox (burner). Absent a showing of criticality or unexpected results, the claimed preheating temperature is not considered to patentably distinguish the instant claims over the cited prior art.
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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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, In Suk Bullock can be reached at (571)272-5954. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Renee Robinson/Primary Examiner, Art Unit 1772
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