Prosecution Insights
Last updated: April 19, 2026
Application No. 17/990,197

METHOD AND APPARATUS FOR ANAEROBIC DIGESTION OF LIQUID WASTE STREAMS

Non-Final OA §103
Filed
Nov 18, 2022
Examiner
PRINCE JR, FREDDIE GARY
Art Unit
1779
Tech Center
1700 — Chemical & Materials Engineering
Assignee
DVO LICENSING, INC.
OA Round
2 (Non-Final)
79%
Grant Probability
Favorable
2-3
OA Rounds
2y 4m
To Grant
99%
With Interview

Examiner Intelligence

Grants 79% — above average
79%
Career Allow Rate
1062 granted / 1347 resolved
+13.8% vs TC avg
Strong +21% interview lift
Without
With
+20.8%
Interview Lift
resolved cases with interview
Typical timeline
2y 4m
Avg Prosecution
32 currently pending
Career history
1379
Total Applications
across all art units

Statute-Specific Performance

§101
0.9%
-39.1% vs TC avg
§103
37.3%
-2.7% vs TC avg
§102
26.2%
-13.8% vs TC avg
§112
28.6%
-11.4% vs TC avg
Black line = Tech Center average estimate • Based on career data from 1347 resolved cases

Office Action

§103
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 . Claim Objections Claim 19 is objected to because of the following informalities: The claim depends from cancelled claim 18 where it appears applicant intended for the claim to depend from claim 16. For examination purposes, the claim is considered to depend from claim 16. Appropriate correction is required. Allowable Subject Matter The indicated allowability of now canceled claims 12 and 18 is withdrawn in view of the newly discovered reference(s) to Dvorak (US 2004/0087011). Instant claim 1 does not include all the limitations of the intervening claims from which now cancelled claim 7 previously depended and therefore instant claim 1 was not previously indicated by the examiner as allowed/allowable. Rejections based on the newly cited reference(s) follow. 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. Claims 1-5, 11 and 16 are rejected under 35 U.S.C. 103 as being unpatentable over Dvorak (US 2010/0140169) in view of Dvorak (US 2004/0087011). Per claim 1, Dvorak (‘169) discloses a system comprising: an acid forming chamber (630) that at least partially converts carbon molecules in a liquid waste to acids ([0004] In one embodiment, the invention provides a system for treating liquid waste comprising an acid forming chamber that at least partially converts carbon molecules in the liquid waste to acids); a plug-flow methanic chamber (640) downstream from the acid forming chamber that at least partially converts the acids in the liquid waste to methane ([0004] a plug-flow methanic chamber downstream from the acid forming chamber that at least partially converts the acids in the liquid waste to methane,); a functional equivalent of a weir structure (659, 661) provided between the acid forming chamber and the methanic chamber ([0066] A cutout 659 is formed in a wall 661 between the acid forming chamber 630 and the methanic chamber 640 to allow liquid waste to plug flow from the acid forming chamber 630 into the methanic chamber 640.); a solid-liquid separator downstream from the methanic chamber, the separator separating a portion of the liquid waste into alkaline sludge and effluent ([0004] a solid-liquid separator downstream from the methanic chamber, the separator separating a portion of the liquid waste into alkaline sludge and effluent,); and a first flow path that recycles alkaline sludge to at least one of the acid forming chamber, the methanic chamber, and combinations thereof ([0004] and a first flow path that recycles alkaline sludge to at least one of the acid forming chamber, the methanic chamber,). Dvorak (‘169) does not explicitly disclose wherein the weir structure has a first weir wall at a level below an operating liquid level of both the acid forming chamber and methanic chamber, and further wherein the weir structure has a second weir wall at a level approximately equal to the operating liquid level of the acid forming chamber, wherein the operating liquid level of the acid forming chamber is greater than the operating liquid level of the methanic chamber. Dvorak (‘011), also directed toward a system (abstract, Apparatuses and methods for anaerobic digestion of high-solids waste are provided.), discloses wherein a weir structure has a first weir wall (lower panel 161, Fig. 3) and further wherein the weir structure has a second weir wall (upper panel 161; Fig. 3) in order to, for example, control the flow from a first chamber to a second chamber ([0032] As illustrated in FIG. 3, a cutout 160 formed in the wall 162 between the mixing chamber 30 and the digester 40 allows sludge to flow from the mixing chamber 30 into the digester 40. In addition, removable panels 161 may be positioned to block opening 163 in the wall 162. The removable panels shown in FIG. 3 are optional. Removable panels 161 may be removed as needed to allow greater flow from mixing chamber 30 to digester 40, if desired.). Accordingly, it would have been readily obvious for the skilled artisan to modify the system of Dvorak (‘169) such that it includes wherein the weir structure has a first weir wall (lower panel 161, Fig. 3) and further wherein the weir structure has a second weir wall (upper panel 161; Fig. 3) in order to, for example, control the flow from a first chamber to a second chamber. Regarding the limitations of the first weir wall at a level below an operating liquid level of both the acid forming chamber and methanic chamber, and the second weir wall at a level approximately equal to the operating liquid level of the acid forming chamber, wherein the operating liquid level of the acid forming chamber is greater than the operating liquid level of the methanic chamber, it is submitted that the limitations are of intended use or process limitations and fail to add structure to the system of Dvorak (‘169), as modified by Dvorak (‘011). Clearly, the operating levels of the chambers may vary, depending on the volume of liquid in the chambers and/or rate at which liquid is fed into the chambers and, as such, the operating levels do not impose additional structure on the weirs. Further, it is well settled that “apparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469 (Fed. Cir. 1990). Claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function. In re Schreiber, 128 F.3d 1473, 1477-78 (Fed Cir. 1997). Moreover, the system of Dvorak (‘169), as modified by Dvorak (‘011), appears to be capable of the first weir wall being at a level below an operating liquid level of both the acid forming chamber and methanic chamber, and the second weir wall being at a level approximately equal to the operating liquid level of the acid forming chamber, wherein the operating liquid level of the acid forming chamber is greater than the operating liquid level of the methanic chamber. Per claim 2, Dvorak (‘169) discloses further comprising a center wall (661, 665; Fig. 9) which divides the methanic chamber into a first leg and a second leg ([0070] A center wall 665 divides the methanic chamber 640 into a first leg or passageway 646 and second leg or passageway 648 of the U-shape.). Per claim 3, Dvorak (‘169) discloses wherein a portion (661) of the center wall (661, 665) forms a partial division between the acid forming chamber and the methanic chamber ([0066] A cutout 659 is formed in a wall 661 between the acid forming chamber 630 and the methanic chamber 640 to allow liquid waste to plug flow from the acid forming chamber 630 into the methanic chamber 640.; Fig. 9). Per claim 4, Dvorak (‘169) discloses further comprising an enclosure (620) surrounding the acid forming chamber, the methanic chamber, the solid-liquid separator and the first flow path ([0065] As shown in FIG. 9, the waste treatment system 610 includes a digester enclosure 620, an acid forming chamber 630, a methanic chamber 640, a sludge pit 660 and an effluent pit 650.). Per claim 5, Dvorak (‘169) discloses wherein the weir structure is positioned between the enclosure and the portion of the center wall forming the partial division between the acid forming chamber and the methanic chamber (Fig. 9, [0066] A cutout 659 is formed in a wall 661 between the acid forming chamber 630 and the methanic chamber 640 to allow liquid waste to plug flow from the acid forming chamber 630 into the methanic chamber 640.). Per claim 11, Dvorak (‘169) discloses a system comprising: an acid forming chamber (630) that at least partially converts carbon molecules in a liquid waste to acids ([0004] In one embodiment, the invention provides a system for treating liquid waste comprising an acid forming chamber that at least partially converts carbon molecules in the liquid waste to acids); a plug-flow methanic chamber (640) downstream from the acid forming chamber that at least partially converts the acids in the liquid waste to methane ([0004] a plug-flow methanic chamber downstream from the acid forming chamber that at least partially converts the acids in the liquid waste to methane,); a functional equivalent of a weir structure (659, 661) provided between the acid forming chamber and the methanic chamber ([0066] A cutout 659 is formed in a wall 661 between the acid forming chamber 630 and the methanic chamber 640 to allow liquid waste to plug flow from the acid forming chamber 630 into the methanic chamber 640.), wherein the weir structure has a first weir wall at a level inherently below an operating liquid level of both the acid forming chamber and methanic chamber since the liquid flows into the methanic chamber from the cutout. If the cutout were above an operating liquid level of both the acid forming chamber and methanic chamber the liquid would not be able to flow through the cutout. Further, it is the examiner’s position that the weir being below an operating liquid level of the acid forming chamber and methanic chamber, is a process and/or or intended use limitation that fails to add structure to the claim. Dvorak (‘169) does not disclose further wherein the weir structure has a second weir wall at a level approximately equal to the operating liquid level of the acid forming chamber, wherein the operating liquid level of the acid forming chamber is greater than the operating liquid level of the methanic chamber. Dvorak (‘011), also directed toward a system (abstract, Apparatuses and methods for anaerobic digestion of high-solids waste are provided.), discloses wherein a weir structure has a second weir wall (upper panel 161; Fig. 3) in order to, for example, control the flow from a first chamber to a second chamber ([0032] As illustrated in FIG. 3, a cutout 160 formed in the wall 162 between the mixing chamber 30 and the digester 40 allows sludge to flow from the mixing chamber 30 into the digester 40. In addition, removable panels 161 may be positioned to block opening 163 in the wall 162. The removable panels shown in FIG. 3 are optional. Removable panels 161 may be removed as needed to allow greater flow from mixing chamber 30 to digester 40, if desired.). Accordingly, it would have been readily obvious for the skilled artisan to modify the system of Dvorak (‘169) such that it includes wherein the weir structure has a second weir wall (upper panel 161; Fig. 3) in order to, for example, control the flow from a first chamber to a second chamber. Regarding the limitation of the second weir wall at a level approximately equal to the operating liquid level of the acid forming chamber, wherein the operating liquid level of the acid forming chamber is greater than the operating liquid level of the methanic chamber, it is submitted that the limitation is one of intended use or a process and fails to add structure to the system of Dvorak (‘169), as modified by Dvorak (‘011). Clearly, the operating levels of the chambers may vary, depending on the volume of liquid in the chambers and/or rate at which liquid is fed into the chambers and, as such, the operating levels do not impose additional structure on the weirs. Further, it is well settled that “apparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469 (Fed. Cir. 1990). Claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function. In re Schreiber, 128 F.3d 1473, 1477-78 (Fed Cir. 1997). Moreover, the system of Dvorak (‘169), as modified by Dvorak (‘011), appears to be capable of the second weir wall being at a level approximately equal to the operating liquid level of the acid forming chamber, wherein the operating liquid level of the acid forming chamber is greater than the operating liquid level of the methanic chamber. Per claim 16, Dvorak (‘169) discloses a system comprising: an enclosure (20) surrounding an acid forming chamber (30) and a methanic chamber (40) that is downstream from the acid forming chamber, wherein the enclosure has a roof (90): a center wall (65) that divides the methanic chamber into a first leg and a second leg; wherein a portion of the center wall forms a partial division between the acid forming chamber and the methanic chamber (as circled below on Fig. 1 of Dvorak (‘169)); PNG media_image1.png 567 480 media_image1.png Greyscale Dvorak (‘169) does not explicitly disclose a weir structure positioned between the roof of the enclosure and the portion of the center wall forming the partial division between the acid forming chamber and the methanic chamber and wherein the weir structure has a first weir wall at a level below an operating liquid level of both the acid forming chamber and methanic chamber and further wherein the weir structure has a second weir wall at a level approximately equal to the operating liquid level of the acid forming chamber, wherein the operating liquid level of the acid forming chamber is greater than the operating liquid level of the methanic chamber. Dvorak (‘011), also directed toward a system (abstract, Apparatuses and methods for anaerobic digestion of high-solids waste are provided.), discloses providing a weir structure (162, 160; Fig. 3) positioned between the roof (98) of an enclosure (10) and a portion (162) of a center wall (165) forming a partial division (Fig. 3) between a first chamber (30) and a second chamber (40) and wherein a weir structure has a first weir wall (lower panel 161, Fig. 3) and further wherein the weir structure has a second weir wall (upper panel 161; Fig. 3) in order to, for example, control the flow from a first chamber to a second chamber ([0032] As illustrated in FIG. 3, a cutout 160 formed in the wall 162 between the mixing chamber 30 and the digester 40 allows sludge to flow from the mixing chamber 30 into the digester 40. In addition, removable panels 161 may be positioned to block opening 163 in the wall 162. The removable panels shown in FIG. 3 are optional. Removable panels 161 may be removed as needed to allow greater flow from mixing chamber 30 to digester 40, if desired.). Accordingly, it would have been readily obvious for the skilled artisan to modify the system of Dvorak (‘169) such that it includes a weir structure positioned between the roof of the enclosure and the portion of the center wall forming the partial division between the acid forming chamber and the methanic chamber and wherein the weir structure has a first weir wall and further wherein the weir structure has a second weir wall in order to, for example, control the flow from a first chamber to a second chamber. Regarding the limitations of the first weir wall at a level below an operating liquid level of both the acid forming chamber and methanic chamber, and the second weir wall at a level approximately equal to the operating liquid level of the acid forming chamber, wherein the operating liquid level of the acid forming chamber is greater than the operating liquid level of the methanic chamber, it is submitted that the limitations are of intended use or process limitations and fail to add structure to the system of Dvorak (‘169), as modified by Dvorak (‘011). Clearly, the operating levels of the chambers may vary, depending on the volume of liquid in the chambers and/or rate at which liquid is fed into the chambers and, as such, the operating levels do not impose additional structure on the weirs. Further, it is well settled that “apparatus claims cover what a device is, not what a device does.” Hewlett-Packard Co. v. Bausch & Lomb Inc., 909 F.2d 1464, 1469 (Fed. Cir. 1990). Claims directed to an apparatus must be distinguished from the prior art in terms of structure rather than function. In re Schreiber, 128 F.3d 1473, 1477-78 (Fed Cir. 1997). Moreover, the system of Dvorak (‘169), as modified by Dvorak (‘011), appears to be capable of the first weir wall being at a level below an operating liquid level of both the acid forming chamber and methanic chamber, and the second weir wall being at a level approximately equal to the operating liquid level of the acid forming chamber, wherein the operating liquid level of the acid forming chamber is greater than the operating liquid level of the methanic chamber. Allowable Subject Matter Claims 8-10, 13-15, 19 and 20 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims. While claims 1, 11 and 16 are not patentable for the reasons provided above, in the examiner’s opinion, the prior art fails to teach or render obvious the system further comprising the limitations of claims 8-10, 13-15, 19 and 20. Response to Arguments Applicant's arguments filed November 7, 2025 have been fully considered but they are not persuasive for the reasons provided above. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to FRED PRINCE whose telephone number is (571)272-1165. The examiner can normally be reached M-F: 0900-1730. 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, Bobby Ramdhanie can be reached at (571)270-3240. 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. /FRED PRINCE/ Primary Examiner Art Unit 1779
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Prosecution Timeline

Nov 18, 2022
Application Filed
Apr 17, 2025
Non-Final Rejection — §103
Oct 22, 2025
Response Filed
Dec 22, 2025
Non-Final Rejection — §103 (current)

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Prosecution Projections

2-3
Expected OA Rounds
79%
Grant Probability
99%
With Interview (+20.8%)
2y 4m
Median Time to Grant
Moderate
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