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 .
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 16 January 2026 has been entered.
Claim Amendments
Applicant’s amendments to the claims filed 16 January 2026 acknowledged. The prior claim objections and most rejections under 35 USC 112 are withdrawn. However, the amendments did not resolve the indefiniteness associated with the term “clarified light oil” presented by the claims and no remarks were directed to this limitation in the response filed 16 January 2026.
Claim Rejections - 35 USC § 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.
Claims 3 and 14 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.
Claims 3 and 14 use the term “clarified light oil.” This term is not well known in the art and is not defined by the specification. While the terms clarified oil and light oil are individually well known, the fact that clarified light oil is given its own acronym (CLO) and is sometimes capitalized in the specification leaves it unclear if this is referring to a specially prepared composition or is simply light oil that has been clarified by some method. One rare instance of the term in the prior art is by Sugumaran et al. (Energy & Fuels 2015 29 (5), 2940-2950), who uses the term to mean an aromatic rich cut of petroleum distillate with boiling points in the range of approximately 320 °C to 540 °C (Section 3.1.1). For the purposes of examination, any of these interpretations may be used.
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.
Claims 1, 5, and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Freymeyer et al. (US 5,350,503) in view of Pradeep et al. (US 2019/0225892 A1), Smith (US 4251323 A), and Farago et al. (US 3,966,560 A), with evidence provided by Huh et al. (US 4919792 A).
Freymeyer teaches a method for producing consistent high quality, anode-grade coke (title and col. 2, line 35). One embodiment taught by Freymeyer is depicted in Figure 3 of their patent, which is copied below. However, many of the features in this Figure are described as optional or could be excluded with a predictable loss of function.
[AltContent: textbox ([img-media_image1.png]
Figure 3 of Freymeyer (US 5,350,503) with label number 58 added for clarity. )]
Elements 42, 66, 68, 70, and 72 are indicated as optional variations (or can be passed via conduits 66 and 68, etc.; col. 6, lines 46-54), and so one of ordinary skill can exclude those features downstream of 64 from the method with a predictable loss of function. Likewise, streams 32 (in one variation a drawstream 32 is taken; col. 6, lines 38-39) and 98 (additional streams can be fed to the second fractionator for separations such as a rich oil stream 98; col. 6, line 67-col. 7, line 1) are also optional and could be excluded with predictable loss of function. The treatment of the overhead stream 74 is also optional (overhead stream 74 of the second fractionator 58 can be passed through cooler/condenser 76 to separator 78), as is the return stream 84 (coker fractionator product stream 83 can pass via conduit 84 as reflux or recycle to the second fractionator 58). Quench oil stream 50 is indicated as having the function of controlling the temperature of the coker overhead and could be removed and replaced with an alternative method of temperature control (col. 6, lines 36-37) by one having ordinary skill in the art. Alternatively, stream 50 can be considered as part of the coker drum operations. Therefore the method of Freymeyer can be viewed as teaching a method consisting of the features shown in the figure below.
[AltContent: textbox ([img-media_image2.png]
Figure 3 of Freymeyer (US 5,350,503) which has been modified include label number 58 and to remove certain optional features, as described in the text.)]
Freymeyer therefore teaches a method for production of anode grade coke in a delayed coker unit (DCU), the method consisting of the following steps, with elements indicated as numbered by Freymeyer and labeled in the figure above:
routing a desalted stream (40) to a pre-separator vessel to fractionate the desalted stream to obtain a lighter stream having a boiling point <300 °C (the first fractionator 48 overhead 60 temperature is in the range of about 525 °F (274 °C) to about 575 °F (302 °C); col. 7, line 15-16), and a heavier stream fraction having a boiling point >300 °C (46, which is maintained at a temperature in the range of about 700 °F (370 °C) to about 800 °F (430 °C); col. 7, lines 9-10);
adding an aromatic stream to a bottom of the pre-separator vessel to fractionate the aromatic stream within the pre-separator vessel for separating a lighter boiling valuable fraction (300 °C-), and a heavier boiling fraction (300 °C+) (the 2/4/6 stream contains catalytic cracker slurry oil which will make this stream aromatic, as evidenced by Huh (col. 1, lines 7-8), and it is being fed into the same vessel performing the separation described above);
mixing the lighter boiling valuable fraction from the aromatic stream with the lighter stream of the crude oil having a boiling point <300 °C, and mixing the heavier boiling fraction from the aromatic stream with the heavier stream fraction of the crude oil having a boiling point >300 °C in the pre-separator vessel to form a mixed feed stream (because both fractions are in the pre-fractionator together, these fractions will necessarily be mixed);
routing the mixed feed stream from the pre-separator vessel directly to a furnace to obtain a heated effluent stream (bottoms 46 is fed to the coker heater 12; col. 6, line 33);
feeding the heated effluent stream from the furnace to a coke drum for cracking into coke (passes to the coker 20; col. 6, line 35), and to generate a coke drum effluent (coker overhead 26);
mixing a gaseous product stream from the main fractionator with the lighter stream having a boiling point <300 °C, and sending for processing (the lighter stream 60 is routed to the main fractionator where it will mix with the gaseous products of the main fractionator which are sent for processing via line 74);
obtaining from the main fractionator a light coker gas oil (bottom stream from the second fractionator [58] can be withdrawn via conduit 62 through conduit 64 as a light coker oil draw; col. 6, lines 44-46) and a fuel oil (stove oil via 88; col. 6, lines 63-65) as well as a heavy coker gas oil from the pre-separator (a drawstream 32 is taken from the first fractionator which draw can be a heavy coker gas oil; col. 6, lines 39-40).
Freymeyer does not explicitly teach charging a sour crude oil to a desalter unit to obtain a desalted stream, but the fact that crude stream 40 is desalted crude (column 6, line 28) implies that it was obtained after charging a crude oil stream to a desalter unit; alternatively, doing so would have been obvious to one of ordinary skill in the art as a means to obtain desalted crude.
Freymeyer does not teach:
the crude oil being sour and having a sulfur content of 3 wt.%, nitrogen content of 0.13 wt.%, and Conradson Carbon Residue (CCR) of 8.21 wt.%,
routing the coke drum effluent to a main fractionator to obtain a light coker gas oil, a heavy coker gas oil, and a fuel oil;
routing the coke obtained from the coke drum to a feed silo and obtaining raw coke; or
calcining the raw coke in a kiln and routing the calcined coke to a cooler to obtain the anode grade coke with a crystallite size (Lc) of 38 A.
Regarding the feedstock composition, while Freymeyer teaches that the desalted crude is preferably a sulfur diluent, they also teach that their method is capable of dealing with sulfur-contaminants in the feedstocks provided and that the balancing crude may be from a different source that the base crude of the remaining feedstock (abstract).
Therefore it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to use a variety of crude oil sources, including those that have high-sulfur such as a sour crude with the instantly claimed composition. One of ordinary skill in the art would have been motivated to do so because Freymeyer teaches that their method works on a variety of feedstocks (column 1, lines 45-51), and it is the overall composition of the mixture of desalted crude and the aromatic stream (balanced stream) that will determine the effectiveness of the procedure taught by Freymeyer. Applying the method otherwise taught by Freymeyer to the specific composition recited is thus considered an obvious variation in view of Freymeyer teaching that their method is applicable to a variety of feedstocks.
Regarding routing the coke drum effluent to the main fractionator instead of the pre-separator vessel, Pradeep teaches a similar method of processing crude oil to Freymeyer and that their method maximizes residue conversion to valuable products (abstract). Pradeep specifically teaches routing coke drum effluent to a main fractionator to obtain light coker gas oil (36), heavy coker gas oil, fuel oil (product vapors (44) are routed to the fractionator column (27) for fractionation into desired product cuts; light gas oil (36), heavy gas oil (37), and fuel oil (38) are indicated; [0052] and Fig. 2), thereby preventing intermixing of coke drum effluent with the crude oil and aromatic stream.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to route the coke drum effluent in the method of modified Freymeyer instead to the main fractionator to obtain light coker gas oil, heavy coker gas oil, and fuel oil from this fractionator, thereby preventing intermixing of coke drum effluent with the crude oil and aromatic stream, as taught by Pradeep. One of ordinary skill in the art would have been motivated to do so because Pradeep teaches that this is an alternative method of stream routing that is able to maximize residue conversion to valuable products.
Regarding routing the coke to a feed silo and subsequent steps, Smith teaches routing coke obtained from coke drum to feed silo and obtaining raw coke (green delayed petroleum coke is fed …to feed hopper; column 4, lines 29-30; having the green (raw) coke in the hopper means it was obtained), calcining the coke in a kiln (coke flows through the calciner; column 4, line 34) and routing the calcined coke to cooler (calcined coke leaving the combustion zone such that calcined coke is cooled; column 5, line 16-17) to obtain anode grade coke (calcined product may be used to produce anodes; column 1, lines 9-10).
Both Freymeyer and Smith are silent on the crystallite size of the obtained anode grade coke. However, Farago teaches a method of calcining coke in a rotary kiln (title) in which the crystallite size can be increased up 35 Å and that this increase in crystallite size represents an improvement (col. 2, lines 8-14). A crystallite size of 35 Å will meet the claim limitation of being greater than ~37 Å, where the inclusion of the approximately symbol (~) is interpreted as the claim including crystallites of 35 Å.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to further modify the method Freymeyer with the coke processing steps taught by Smith and the specific calcining technique of Farago.
One of ordinary skill would have been motivated to add the method steps of Smith to the method of modified Freymeyer because while Freymeyer teaches the use of the coke for anodes, they are silent on the processing steps required to do so. They would have been additionally motivated to optimize the crystallite size according to the method of Farago because Farago teaches that larger crystallite represent an improved coke quality, a stated objective of Freymeyer.
Regarding claim 5, modified Freymeyer teaches the method of claim 1, where the heated effluent stream from the furnace has a temperature in the range of about 480 °C to about 540 °C (about 900 °F to about 1000 °F; col. 5, lines 27-28), which overlaps with the instantly claimed range of 480 °C-510 °C.
It is noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” and even when the claimed ranges and prior art ranges do not overlap but are close enough that one skilled in the art would have expected them to have similar properties, a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01).
Generally, differences in temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 II(A).
Therefore, the claimed ranges of temperatures merely represent an obvious variant and/or routine optimization of the values of the cited prior art.
Regarding claim 10, modified Freymeyer teaches the method of claim 1 and discloses that the coke produced can be of anode grade (col. 2, line 35). Because the method of modified Freymeyer and the instant claims are the same, the anode grade coke produced by each will have largely similar impurity profiles.
Where the claimed and prior art products are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). "When the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not." In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990).
Additionally, Freymeyer teaches that contaminant composition of the feed stream affects the contaminant content of the coke produced, and that adjusting the former using a balancing stream can improve the contaminant content of the coke produced (column 2, lines 52-57).
Accordingly, one of ordinary skill in the art before the effective filing date of the invention would have optimized, by routine experimentation, the feedstock balancing, as taught by Freymeyer, in order to obtain the desired sulfur and nitrogen wt% in the coke produced. One would be motivated to do so because such impurities act as poisons for downstream units, as taught by Pradeep ([0037]) and because high quality anode-grade coke is needed for application such as aluminum production, as taught by Freymeyer (column 2, lines 34-37).
Claim 3 is rejected under 35 U.S.C. 103 as being unpatentable over Freymeyer et al. (US 5,350,503) in view of Pradeep et al. (US 2019/0225892 A1), Smith (US 4251323 A), and Farago et al. (US 3,966,560 A) with evidence provided by Huh et al. (US 4919792 A), as applied to claim 1, and further in view of Sugumaran et al. (Energy & Fuels 2015 29 (5), 2940-2950) with evidence provided by Delek (Slurry Oil, Safety Data Sheet. [Retrieved on 2025-06-13]. Retrieved from the Internet: < URL: https://s204.q4cdn.com/601669363/files/doc_downloads/sdss/Slurry_Oil_SDS_NA2015_101322_FINAL-1.pdf>).
Regarding claim 3, modified Freymeyer teaches the method of claim 1 where the aromatic stream (2/4/6) contains catalytic cracker slurry oil, which is considered a clarified light oil, as evidenced by Delek and Sugumaran.
Delek lists cracked slurry oil and cracked clarified oils as synonyms (Section 1.1), and further describes the clarified oil components as having boiling points above about 350 °C (Section 3.2), and Sugumaran clarifies that CLO is a higher cut fraction with boiling points in a overlapping range (320 °C to 540 °C; Section 3.1.1) to that of the product described by Delek.
If these oils are not in fact identical, it would have been obvious to one of ordinary skill in the art to replace in the method of modified Freymeyer the cracked slurry oil taught by Freymeyer with a clarified light oil, such as that taught by Sugumaran. One of ordinary skill in the art would have been motivated to do so because the two oils have similar properties (with respect to being aromatic and covering compounds with overlapping boiling point ranges) and would therefore represent the simple substitution of one known clarified oil for another with predictable results. MPEP 2143(I)(B).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Freymeyer et al. (US 5,350,503) in view of Pradeep et al. (US 2019/0225892 A1), Smith (US 4251323 A), and Farago et al. (US 3,966,560 A), with evidence provided by Huh et al. (US 4919792 A), as applied to claim 1, and further in view of Ellis and Paul (Tutorial: Delayed Coking Fundamentals, Great Lakes Carbon Corporation, presented at the AIChE 1998 Spring National Meeting, March 1998. Retrieved from <URL: http://coking.com/wp-content/uploads/sites/2/2013/11/DelayedCokingFundamentals.pdf>. Archived [2014-09-12].)
Regarding claim 4, modified Freymeyer teaches the method of claim 1, where Freymeyer teaches the coke drum being maintained at 20.0 psia (5.3 psig) to about 60.0 psia (45.3 psig, col. 5, line 36) which is equivalent to a range of about 0.4 Kg/cm2 to about 3.2 Kg/cm2 gauge pressure. The ranges of pressures taught by Freymeyer overlap with the instantly claimed pressures (1 to 5 Kg/cm2). Freymeyer is silent on the overhead temperature of the coke drums.
However, Ellis gives a tutorial on delayed coking fundamentals (title) and teaches that overhead temperatures in a coking drum are typically around 443 °C (p. 11, ¶ 2), which falls in the instantly claimed range of 430 °C to 460 °C.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to operate the coking drums in the method of Freymeyer at an overhead temperature of 443 °C, as taught by Ellis. One of ordinary skill in the art would have been motivated to do so because while Freymeyer is silent on this value, Ellis teaches that it a typical temperature used in the art.
It is also noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01). Therefore it would have also been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to operate the coking drums at any pressure in the range taught by Freymeyer, 0.4 Kg/cm2 to 3.2 Kg/cm2, including the overlapping portion with the instantly claimed range, 1 Kg/cm 2 to 3.2 Kg/cm2.
Claims 11, 16 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Freymeyer et al. (US 5,350,503) in view of Pradeep et al. (US 2019/0225892 A1), Janssen (EP 0087968 A2), and Smith (US 4251323 A), with evidence provided by Hunt (Petroleum Geochemistry and Geology, San Francisco: W.H. Freeman, 1979. p. 45).
Regarding claim 11, Freymeyer teaches a method for producing consistent high quality, anode-grade coke in a delayed coker unit (title and col. 2, line 35). One embodiment taught by Freymeyer is depicted in Figure 3 of their patent, which is copied below. However, many of the features in this Figure are described as optional or could be excluded with a predictable loss of function.
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Elements 42, 70, and 72 are indicated as optional variations (col. 6, lines 46-54), and so one of ordinary skill can exclude those features downstream of 70 from the method with a predictable loss of function. Likewise, stream 98 (additional streams can be fed to the second fractionator for separations such as a rich oil stream 98; col. 6, line 67-col. 7, line 1), the downstream treatments of the overhead stream 74, (overhead stream 74 of the second fractionator 58 can be passed through cooler/condenser 76 to separator 78), and the return stream 84 (coker fractionator product stream 83 can pass via conduit 84 as reflux or recycle to the second fractionator 58) are optional and could be excluded with predictable loss of function. Quench oil stream 50 is indicated as having the function of controlling the temperature of the coker overhead and could be removed and replaced with an alternative method of temperature control (col. 6, lines 36-37) by one having ordinary skill in the art. Alternatively, stream 50 can be considered as part of the coker drum operations. Therefore the method of Freymeyer can be [AltContent: textbox ([img-media_image3.png]
Figure 3 of Freymeyer (US 5,350,503) which has been modified include label number 58 and to remove certain optional features, as described in the text.)]viewed as teaching a method consisting of the features shown in the figure below.
Freymeyer therefore teaches a method for production of anode grade coke in a delayed coker unit (DCU), the method consisting of the following steps, with elements indicated as numbered by Freymeyer and labeled in the figure above:
routing a desalted stream (40) to a pre-separator vessel to obtain a lighter stream having a boiling point <300 °C (the first fractionator 48 overhead 60 temperature is in the range of about 525 °F (274 °C) to about 575 °F (302 °C); col. 7, line 15-16), and a heavier stream fraction having a boiling point >300 °C (46, which is maintained at a temperature in the range of about 700 °F (370 °C) to about 800 °F (430 °C); col. 7, lines 9-10);
routing a mixed feed stream to a furnace to obtain a heated effluent stream (bottoms 46 is fed to the coker heater 12; col. 6, line 33);
feeding the heated effluent stream from the furnace to a coke drum for cracking into coke (passes to the coker 20; col. 6, line 35), and to obtain a coke drum effluent (coker overhead 26);
mixing a gaseous product stream from the main fractionator with the lighter stream having a boiling point <300 °C from the pre-separator vessel, and sending for processing (the lighter stream 60 is routed to the main fractionator where it will mix with the gaseous products of the main fractionator which are sent for processing via line 74);
obtaining from the main fractionator a light coker gas oil (bottom stream from the second fractionator 58 can be withdrawn via conduit 62 through conduit 64 as a light coker oil draw; col. 6, lines 44-46) and a fuel oil (stove oil via 88; col. 6, lines 63-65) as well as a heavy coker gas oil from the pre-separator (a drawstream 32 is taken from the first fractionator which draw can be a heavy coker gas oil; col. 6, lines 39-40).
Freymeyer also teaches a recycle stream (68) from the main fractionator (58) being fed back to the pre-separator (48; col. 6, lines 47-48), where it will mix with the heavier stream having the boiling point >300 °C (46) to produce a mixed feed stream.
Freymeyer does not explicitly teach charging a hydrocarbon feedstock to a desalter unit to obtain a desalted stream, but the fact that crude stream 40 is desalted crude (column 6, line 28) implies that it was obtained after charging a hydrocarbon feedstock to a desalter unit; alternatively, doing so would have been obvious to one of ordinary skill in the art as a means to obtain desalted crude.
Freymeyer does not teach:
routing an aromatic stream to a bottom of a main fractionator wherein the aromatic stream condenses heavier molecules from a coke drum effluent to form the recycle stream;
routing the coke drum effluent to a main fractionator to obtain a light coker gas oil, a heavy coker gas oil, a fuel oil, and a gaseous stream;
routing the coke obtained from the coke drum to a feed silo and obtaining raw coke; or
calcining the raw coke in a kiln and routing the calcined coke to a cooler to obtain the anode grade coke
Regarding routing the coke drum effluent to the main fractionator instead of the pre-separator vessel, Pradeep teaches a similar method of processing crude oil to Freymeyer and that their method maximizes residue conversion to valuable products. Pradeep specifically teaches routing coke drum effluent to a main fractionator to obtain light coker gas oil (36), heavy coker gas oil, fuel oil and a gaseous stream (product vapors (44) are routed to the fractionator column (27) for fractionation into desired product cuts; light gas oil (36), heavy gas oil (37), fuel oil (38), and a gaseous naphtha stream (35) are indicated; [0052] and Fig. 2), thereby preventing intermixing of coke drum effluent with the sour crude oil.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to route the coke drum effluent in the method of modified Freymeyer instead to the main fractionator and to obtain light coker gas oil, heavy coker gas oil, fuel oil and a gaseous stream from this fractionator, as taught by Pradeep. One of ordinary skill in the art would have been motivated to do so because Pradeep teaches that this is an alternative method of stream routing that is able to maximize residue conversion to valuable products.
Regarding routing an aromatic stream to a bottom of a main fractionator, Janssen teaches routing an aromatic stream (heavy gas oil) to a bottom of a main fractionator to condenses heavier molecules from a coke drum effluent (a portion of the gas oil is returned to a spray nozzle 20 where it is utilized to knock down entrained material and condense the heavier components of the vapor entering [from] the coke drum [via] line 22; page 5, line 33 to page 6, line 3 and Fig. 1). Heavy gas oil can be considered an aromatic stream, as evidenced by Hunt, who shows that it contains about 20% aromatics (aromatics and naphthenoaromatics, Figure 3-7; p. 45).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to route an aromatic stream to the bottom of the main fractionator in the method of modified Freymeyer in order to condenses heavier molecules from a coke the drum effluent, as taught by Janssen. One would have been motivated to do so because Janssen teaches that doing so helps to prevent deposition of coke on the furnace tubes (p. 6, lines 19-20).
Regarding routing the coke to a feed silo and calcining the raw coke in a kiln, and routing the coke to a cooler, Smith teaches routing coke obtained from coke drum to feed silo and obtaining raw coke (green delayed petroleum coke is fed …to feed hopper; column 4, lines 29-30; having the green (raw) coke in the hopper means it was obtained), calcining the coke in a kiln (coke flows through the calciner; column 4, line 34) and routing the calcined coke to cooler (calcined coke leaving the combustion zone such that calcined coke is cooled; column 5, line 16-17) to obtain anode grade coke (calcined product may be used to produce anodes; column 1, lines 9-10).
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to further modify the method Freymeyer with the coke processing steps taught by Smith. One of ordinary skill would have been motivated to add the method steps of Smith to the method of modified Freymeyer because while Freymeyer teaches the use of the coke for anodes, they are silent on the processing steps required to do so.
Regarding claim 16, modified Freymeyer teaches the method of claim 11, where the heated effluent stream from the furnace has a temperature in the range of about 480 °C to about 540 °C (about 900 °F to about 1000 °F; col. 5, lines 27-28), which overlaps with the instantly claimed range of 480 °C-510 °C.
It is also noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” and even when the claimed ranges and prior art ranges do not overlap but are close enough that one skilled in the art would have expected them to have similar properties, a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01).
Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). See MPEP 2144.05 II(A).
Therefore, the claimed ranges of temperatures merely represent an obvious variant and/or routine optimization of the values of the cited prior art.
Regarding claim 17, modified Freymeyer teaches the method of claim 11 and discloses that the coke produced can be of anode grade (col. 2, line 35). Because the method of modified Freymeyer and the instant claims are the same, the anode grade coke produced by each will have largely similar impurity profiles.
Where the claimed and prior art products are produced by identical or substantially identical processes, a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). "When the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not." In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990).
Additionally, Freymeyer teaches that contaminant composition of the feed stream affects the contaminant content of the coke produced, and that adjusting the former using a balancing stream can improve the contaminant content of the coke produced (column 2, lines 52-57).
Accordingly, one of ordinary skill in the art before the effective filing date of the invention would have optimized, by routine experimentation, the feedstock balancing, as taught by Freymeyer, in order to obtain the desired sulfur and nitrogen wt% in the coke produced. One would be motivated to do so because such impurities act as poisons for downstream units, as taught by Pradeep ([0037]) and because high quality anode-grade coke is needed for application such as aluminum production, as taught by Freymeyer (column 2, lines 34-37).
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Freymeyer et al. (US 5,350,503) in view of Pradeep et al. (US 2019/0225892 A1), Janssen (EP 0087968 A2), and Smith (US 4251323 A), with evidence provided by Hunt (Petroleum Geochemistry and Geology, San Francisco: W.H. Freeman, 1979. p. 45), as applied to claim 11, and further in view of Sugumaran et al. (Energy & Fuels 2015 29 (5), 2940-2950) with evidence provided by Delek (Slurry Oil, Safety Data Sheet. [Retrieved on 2025-06-13]. Retrieved from the Internet: < URL: https://s204.q4cdn.com/601669363/files/doc_downloads/sdss/Slurry_Oil_SDS_NA2015_101322_FINAL-1.pdf>).
Regarding claim 14, modified Freymeyer teaches the method of claim 11, where Janssen teaches the aromatic stream being used is heavy coker gas oil feedstock that is withdrawn from the fractionator. Janssen further teaches that the oil sprayed into the fractionator to condense (knock down) vapors contribute to total coke production (p. 8, lines 7-15), which they are trying to avoid but others may be looking to promote. Additionally, Freymeyer teaches that the introduction of slurry oil to the system can increase the quality of coke produced (column 2, lines 40-48).
Slurry oil is considered to be synonymous with clarified light oil. This is evidenced by Delek which lists cracked slurry oil and cracked clarified oils as synonyms (Section 1.1), and further describes the clarified oil components as having boiling points above about 350 °C (Section 3.1.1), and Sugumaran who clarifies that CLO is a higher cut fraction with boiling points in an overlapping range (320 °C to 540 °C) to that of the product described by Delek. Even if clarified light oil is not equivalent to cracked slurry oil, it would be obvious to substitute clarified light oil for cracked slurry oil, as they have similar properties, as taught by Sugumaran, and could therefore serve similar functions in the method of modified Freymeyer with predictable results.
Therefore, it would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to substitute the heavy gas oil stream taught Janssen in the method Freymeyer for a stream of slurry oil, or clarified light oil, as taught by Freymeyer and Sugumaran. One of ordinary skill in the art would have been motivated to do so in order to increase the quality of the coke being produced.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Freymeyer et al. (US 5,350,503) in view of Pradeep et al. (US 2019/0225892 A1), Janssen (EP 0087968 A2), and Smith (US 4251323 A), with evidence provided by Hunt (Petroleum Geochemistry and Geology, San Francisco: W.H. Freeman, 1979. p. 45), as applied to claim 11, and further in view of Ellis and Paul (Tutorial: Delayed Coking Fundamentals, Great Lakes Carbon Corporation, presented at the AIChE 1998 Spring National Meeting, March 1998. Retrieved from <URL: http://coking.com/wp-content/uploads/sites/2/2013/11/DelayedCokingFundamentals.pdf>. Archived [2014-09-12].)
Regarding claim 15, modified Freymeyer teaches the method of claim 11, where Freymeyer teaches the coke drum being maintained at 20.0 psia (5.3 psig) to about 60.0 psia (45.3 psig; col. 5, line 36) which is equivalent to a range of about 0.4 Kg/cm2 to about 3.2 Kg/cm gauge pressure, which overlaps with the instantly claimed range of pressures (1 Kg/cm2 to 5 Kg/cm2). Freymeyer is silent on the overhead temperature of the coke drums.
However, Ellis gives a tutorial on delayed coking fundamentals (title) and teaches that overhead temperatures in a coking drum are typically around 443 °C (p. 11, ¶ 2), which falls in the instantly claimed range of 430 °C to 460 °C.
Therefore, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to operate the coking drums in the method of Freymeyer at an overhead temperature of 443 °C, as taught by Ellis. One of ordinary skill in the art would have been motivated to do so because while Freymeyer is silent on this value, Ellis teaches that it a typical temperature used in the art.
It is also noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01). Therefore it would have also been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to operate the coking drums at any pressure in the range taught by Freymeyer, 0.4 Kg/cm2 to 3.2 Kg/cm2, including the overlapping portion with the instantly claimed range, 1 Kg/cm 2 to 3.2 Kg/cm2.
Response to Arguments
Applicant's arguments with respect to rejected claim 1, pages 7-12 of the reply filed 16 January 2026, have been fully considered but they are not persuasive.
In particular, Applicant’s arguments with respect to the characterization of Freymeyer, page 8 of the reply, are based upon the suggestion that the “combination of both the columns is [to be] considered as a single fractionator column.” However, there is no reason to consider these two distinct vessels as one.
To use the language of the instant claims, Freymeyer’s column 48 is the “pre-fractionator vessel” and column 58 is the “main fractionator.” As can be seen below, Applicant’s assertion that a “secondary feed from the main fractionator bottoms is routed to a furnace” is not consistent with the process depicted by Freymeyer. It is a fraction from the pre-separator vessel 48 that is routed to furnace 12 (via conduit 14) and subsequently to the coke drums 18 and 20 (via conduit 14).
It is true that Freymeyer teaches routing the coke drum effluent to the same pre-separator vessel, but this deficiency is cured by Pradeep, who teaches routing coke drum effluent (via line 44) to a main fractionator (27) instead of to a pre-[AltContent: textbox ([img-media_image2.png]
Figure 3 of Freymeyer (US 5,350,503) which has been modified include label number 58 and to remove certain optional features, as described in the text.
[img-media_image4.png]
Figure 2 of Pradeep (US 2019/0225892 A1).)]separator vessel (24), as depicted in below (Fig 2).
The combination of Freymeyer and Pradeep therefore teaches the routing of streams as claimed.
Applicant further argues, pages 9-10, that routing of vacuum tower bottoms derived from high sulfur crude oil would render the method of Freymeyer unsuitable for generating anode grade coke. However, no suggestion was made or implied in the rejection set forth above to use vacuum tower bottoms derived from a sour crude oil. It is Freymeyer’s desalted crude stream 40 that would have been obvious to replace with a desalted stream derived from charging a sour crude to a desalter unit, not any of the vacuum bottoms.
Applicant’s further arguments with respect to the inability of modified Freymeyer to generate anode grade coke, pages 10-12, are based upon on the same premises as above, where it is interpreted that Freymeyer teaches using vacuum residuum from sour crude oil, which is not a requirement of Freymeyer as disclosed or as applied in the rejection set forth. These arguments are therefore not persuasive.
With regards to Applicant’s final argument concerning claim 1, p. 12 ¶ 5, it is noted that the features upon which applicant relies (i.e., that the aromatic stream be selected from the group consisting of pyrolysis tar, aromatic tar, and clarified light oil), are features not recited in claim 1. Although the claims are interpreted in light of the specification, limitations from the specification are not read into the claims. See In re Van Geuns, 988 F.2d 1181, 26 USPQ2d 1057 (Fed. Cir. 1993).
It is noted however, that these feature are recited in rejected claim 3, and so any distinguishing characteristics imparted by these limitations would have also been obvious to one of ordinary skill in the art prior to the effective filing date of the claimed invention, as analyzed for claim 3 above.
Applicant’s arguments with respect claim 4, page 14, is that the pressure range taught by Freymeyer (0.4-3.2 kg/cm2) does not entirely overlap with that of the instant claim (1-5 kg/cm2). However, it is again noted that the courts have stated where the claimed ranges “overlap or lie inside the ranges disclosed by the prior art” a prima facie case of obviousness exists (see In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990); Titanium Metals Corp. of America v. Banner, 778 F2d 775. 227 USPQ 773 (Fed. Cir. 1985) (see MPEP 2144.05.01). This is not a requirement that the ranges be identical or “entirely overlap”, only that values be shared by both ranges, as they are here.
Please see MPEP 2144.05(III) for arguments that may be made to rebut the prima facie case of obviousness established by the overlapping range.
Applicant’s arguments with respect to the remaining claims, pages 13-16 are dependent upon or identical to the arguments presented for claim 1, and are likewise not persuasive for the reasons outlined above.
Conclusion
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/NICHOLAS A. PIRO/Assistant Examiner, Art Unit 1738
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735