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
The Amendment filed 21 January 2026 has been entered. Claims 1, 5, and 9 are amended. Accordingly, claims 1-5 and 7-9 remain pending in the application. Applicant’s amendments to the claims have overcome each and every 112(b) rejection previously set forth in the Non-Final Office Action mailed 22 October 2025.
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.
Claims 1, 5 and 7 are rejected under 35 U.S.C. 103 as being unpatentable over Kiiskila (US 6,146,604) in view of Suchak (US 2012/0076716) and Hale (US 2005/0137332) and Kaverzneva (“Mechanism of the Oxidation of Cellulose with Nitrogen Oxides”).
Regarding Claim 1, Kiiskila discloses a method of removing nitrogen oxides (removing nitrogen oxides meets the limitation of managing and controlling nitrogen emission) in a pulp mill, the pulp mill comprising a recovery boiler (claim 1), wherein chemicals and heat from the pulping process are recovered (Col. 1, lines 11-15). Kiiskila further discloses a scrubber downstream of the recovery boiler (claim 5), which produces nitrate from nitrogen dioxide (claim 6), such that the scrubber of Kiiskila meets the limitation of a nitrogen oxide scrubber. Kiiskila further discloses flue gases from the recovery boiler are transported to a scrubber to produce nitrate (Col. 3, lines 39-47), such that the nitrogen oxide scrubber of Kiiskila is arranged to remove nitrogen oxide from flue gas from the recovery boiler. The system of Kiiskila comprises a recovery boiler and nitrogen oxide scrubber such that the system of Kiiskila meets the limitation of a recovery system. Kiiskila further discloses contacting flue gases from the recovery boiler with a peroxide solution, thereby oxidizing nitrogen oxides in the flue gas (claim 1) to produce nitrogen dioxide (nitrogen dioxide meets the limitation of higher nitrogen oxides; claim 13), wherein the peroxide solution is hydrogen peroxide (claim 14). Kiiskila further discloses contacting the flue gas with an alkaline scrubbing liquor (alkaline scrubbing liquor meets the limitation of an alkaline aqueous scrubber liquid) in the nitrogen oxide scrubber, recovering the nitrogen dioxide and producing nitrate (claims 5 & 6), which is also described as the nitrate-containing scrubbing solution (nitrate-containing scrubbing solution contains nitrogen and therefore, meets the limitation of a nitrogen containing scrubber liquid; Col. 3, line 54). The process of contacting nitrogen oxides with alkaline aqueous scrubber liquid of Kiiskila is substantially similar to that of the claim, as both produce a nitrate product (See pg. 4, lines 9-22 of the Specification of the present application), such that the nitrogen oxides of Kiiskila are absorbed in the scrubber liquid. Kiiskila further discloses the nitrate-containing scrubbing solution may be utilized as nutrient in a biological effluent treatment plant of the pulp mill (claim 18).
Kiiskila is silent to adding the nitrogen containing scrubber liquid to a causticizer of the cyclic liquor flow system or a pulp digester used in the pulping process.
Suchak discloses oxidation of nitrogen oxides resulting in nitrogen trioxide and dinitrogen pentoxide which can be easily absorbed and retain in aqueous medium of a scrubber [0026]. Suchak further discloses the by-product of reaction in the scrubber (nitrate) (aka a nitrogen containing scrubber liquid) is a beneficial effluent for digesting organic impurities in wastewater treatment facilities [0059].
Suchak is silent to using the scrubbing liquid in the digester of a pulp mill.
However, Hale discloses the influent waste stream of a wastewater treatment facility may be high in cellulose materials [0003].
A pulp mill digester digests a cellulosic raw material (See pg. 10 of the Specification of the present application).
Kaverzneva discloses nitrogen oxides are capable of breaking down cellulose (Mechanism on pg. 319).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kiiskila to incorporate the teachings of Suchak, Hale, and Kaverzneva to introduce all or part of the nitrogen containing scrubber liquid into a pulp digester used in the pulping process, because the nitrogen containing scrubber liquid is a beneficial effluent for digesting organic impurities in wastewater treatment facilities, as recognized by Suchak [0059], and wastewater includes cellulose, as recognized by Hale [0003], and nitrogen oxide is known to break down cellulose, as recognized by Kaverzneva (pg. 319).
Regarding Claim 5, Kiiskila is silent to adding the nitrogen containing scrubber liquid to a digester.
Suchak discloses oxidation of nitrogen oxides resulting in nitrogen trioxide and dinitrogen pentoxide which can be easily absorbed and retain in aqueous medium of a scrubber [0026]. Suchak further discloses the by-product of reaction in the scrubber (nitrate) (aka a nitrogen containing scrubber liquid) is a beneficial effluent for digesting organic impurities in wastewater treatment facilities [0059].
Suchak is silent to using the scrubbing liquid in the digester of a pulp mill.
However, Hale discloses the influent waste stream of a wastewater treatment facility may be high in cellulose materials [0003].
A pulp mill digester digests a cellulosic raw material (See pg. 10 of the Specification of the present application).
Kaverzneva discloses nitrogen oxides are capable of breaking down cellulose (Mechanism on pg. 319).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kiiskila to incorporate the teachings of Suchak, Hale, and Kaverzneva to add the nitrogen containing scrubber liquid into the digester in the pulping process, because the nitrogen containing scrubber liquid is a beneficial effluent for digesting organic impurities in wastewater treatment facilities, as recognized by Suchak [0059], and wastewater includes cellulose, as recognized by Hale [0003], and nitrogen oxide is known to break down cellulose, as recognized by Kaverzneva (pg. 319).
Regarding Claim 7, Kiiskila discloses the alkaline scrubbing solution may be sodium hydroxide (Col. 3, lines 39-50).
Claims 2-4 are rejected under 35 U.S.C. 103 as being unpatentable over Kiiskila (US 6,146,604) in view of Suchak (US 2012/0076716) and Hale (US 2005/0137332) and Kaverzneva (“Mechanism of the Oxidation of Cellulose with Nitrogen Oxides”) and Dernjatin (WO 9420676).
Regarding Claim 2, Kiiskila, Suchak, Hale, and Kaverzneva teach the elements as described above with regards to claim 1.
Kiiskila discloses the nitrate-containing scrubbing solution may be transported to a biological effluent treatment plant of the pulp mill where the nitrate is used as a nutrient (Col. 3, lines 54-56).
Kiiskila is silent to adding the nitrogen containing scrubber liquid in one or more parts of the recovery system.
Dernjatin discloses a method for reducing nitrogen oxide emissions from a recovery furnace in a pulp cooking process of a sulfate pulp industry (pg. 5, second paragraph), wherein a recovery furnace refers to a recovery furnace or boiler (reducing nitrogen oxide emissions from a recovery boiler in a pulp cooking process of a sulfate pulp industry meets the limitation of managing and controlling nitrogen emission in a pulp mill; pg. 2, ninth paragraph). Dernjatin further discloses an apparatus (pg. 5, eighth paragraph-pg. 6, first paragraph) for recovering heat and chemicals from a pulping process (pg. 6, first paragraph), the apparatus comprising a recovery boiler (pg. 5, eighth paragraph) and a nitrogen oxide scrubber, the nitrogen oxide scrubber being arranged to remove nitrogen oxide from flue gas from the recovery boiler (pg. 6, fifth paragraph). The system of Dernjatin comprises a recovery boiler and nitrogen oxide scrubber such that the system of Dernjatin meets the limitation of a recovery system. Dernjatin further discloses exposing flue gas from the recovery boiler to an oxidizing agent, thereby oxidizing nitric oxide (aka nitrogen oxide) to nitrogen dioxide (oxidizing nitric oxide to nitrogen dioxide meets the limitation of oxidizing nitrogen oxide to higher nitrogen oxides; pg. 2, sixth and seventh paragraphs); contacting the flue gas with a scrubbing liquid in the nitrogen oxide scrubber, thereby removing nitrogen dioxide (pg. 2, seventh paragraph). Dernjatin further discloses scrubbing liquors are typically in the form of aqueous solutions, and they may contain alkali metal compounds, which appears to meet the limitation of an alkaline aqueous scrubber liquid (pg. 4, fourth paragraph). Dernjatin further discloses absorbed nitrogen compounds in the scrubbing liquid (pg. 1, fourth paragraph), which meets the limitation of producing a nitrogen containing scrubber liquid.
Dernjatin further discloses returning spent scrubbing liquor to the pulp cooking process, such as sending spent scrubbing liquor to the evaporation plant or the dissolving tank of smelt received from the recovery boiler (pg. 4, ninth paragraph). Per the specification of the present application, the recovery system comprises an evaporator (7) and a dissolving tank (10) (Fig. 1), such that Dernjatin's disclosure meets the limitation wherein introduction of all or part of the nitrogen containing scrubber liquid into the cyclic liquor flow system comprises or consists of adding nitrogen containing scrubber liquid in one or more parts of the recovery system. Dernjatin further discloses because the spent scrubbing solution is recycled back to the process, the scrubber consequently produces no waste water which due to the NOx absorption contain nitrite and nitrate ions requiring waste water treatment (pg. 5, third paragraph).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kiiskila to incorporate the teachings of Dernjatin wherein introduction of all or a part of the nitrogen containing scrubber liquid into the cyclic liquor flow system comprises or consists of adding the nitrogen containing scrubber liquid in one or more parts of the recovery system, because Kiiskila teaches utilizing the nitrate-containing scrubbing solution in the pulping process (Col. 3, lines 54-56), rather than sending to waste water treatment; and utilizing the spent scrubbing solution in the recovery system of a pulp mill is a process parameter well-known in the art of managing and controlling nitrogen emissions in a pulp mill, as recognized by Dernjatin, and recycling the spent scrubbing solution back to the process consequently produces no waste water from the scrubber, which due to the NOx absorption, would contain nitrite and nitrate ions requiring waste water treatment, as recognized by Dernjatin (pg. 5, third paragraph).
Regarding Claim 3, Dernjatin discloses returning the spent scrubbing liquor to the pulp cooking process, such as sending spent scrubbing liquor to the dissolving tank of smelt received from the recovery boiler (pg. 4, ninth paragraph).
Regarding Claim 4, Dernjatin discloses spent scrubbing liquor is taken to the evaporation plant and combusted along with the black liquor in the recovery furnace (pg. 8, sixth paragraph). Dernjatin further discloses black liquor is concentrated by evaporation prior to taking it to combustion in the recovery furnace (pg. 6, first paragraph). Therefore, it appears Dernjatin meets the limitation wherein the recovery system comprises an evaporator for concentrating black liquor from the pulping process before supplying the concentrated black liquor to the recovery boiler, and wherein nitrogen containing scrubber liquid is added to the evaporator.
Claims 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Kiiskila (US 6,146,604) in view of Suchak (US 2012/0076716) and Hale (US 2005/0137332) and Kaverzneva (“Mechanism of the Oxidation of Cellulose with Nitrogen Oxides”) and Spontak (US 5,635,027).
Regarding Claim 8, Kiiskila, Suchak, Hale, and Kaverzneva teach the elements as described above with regards to claim 1.
Kiiskila discloses a cellulose pulping process (claim 1), in the pulp and paper industry (Col. 1, line 12).
Kiiskila is silent to the pulping process being a Kraft pulping process.
Spontak discloses the preparation of pulp by the Kraft process (Col. 3, lines 54-55), and the Kraft process is the most common process used for the production of pulp and paper (Col. 1, lines 10-11).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kiiskila to incorporate the teachings of Spontak wherein the pulping process is a Kraft pulping process, because the Kraft pulping process is the most common pulping process, as recognized by Spontak (Col. 1, lines 10-11).
Regarding Claim 9, Kiiskila discloses a pulp mill comprising a recovery boiler (claim 1), wherein chemicals and heat from the pulping process are recovered (Col. 1, lines 11-15). Kiiskila further discloses a scrubber downstream of the recovery boiler (claim 5), which produces nitrate from nitrogen dioxide (claim 6), such that the scrubber of Kiiskila meets the limitation of a nitrogen oxide scrubber. The system of Kiiskila comprises a recovery boiler and nitrogen oxide scrubber such that the system of Kiiskila meets the limitation of a recovery system. Kiiskila further discloses contacting flue gases from the recovery boiler with a peroxide solution in a duct between the boiler bank and the economizer of the heat recovery section of the recovery boiler (such that there is an arrangement for oxidizing upstream the scrubber), thereby oxidizing nitrogen oxides in the flue gas (claim 1) to produce nitrogen dioxide (nitrogen dioxide meets the limitation of higher nitrogen oxides; claim 13), wherein the peroxide solution is hydrogen peroxide (claim 14). Kiiskila further discloses contacting the flue gas with an alkaline scrubbing liquor (alkaline scrubbing liquor meets the limitation of an alkaline aqueous scrubber liquid) in the nitrogen oxide scrubber, recovering the nitrogen dioxide and producing nitrate (claims 5 & 6), which is also described as the nitrate-containing scrubbing solution (nitrate-containing scrubbing solution contains nitrogen and therefore, meets the limitation of a nitrogen containing scrubber liquid; Col. 3, line 54). The process of contacting nitrogen oxides with alkaline aqueous scrubber liquid of Kiiskila is substantially similar to that of the claim, as both product a nitrate product (See pg. 4, lines 9-22 of the Specification of the present application), such that the nitrogen oxides of Kiiskila are absorbed in the scrubber liquid. Kiiskila further discloses the nitrate-containing scrubbing solution may be utilized as nutrient in a biological effluent treatment plant of the pulp mill (claim 18).
Kiiskila is silent to a pulping system comprising a pulp digester and the recovery system comprises a causticizer.
Spontak discloses a chemical recovery cycle of the Kraft process (Col. 3, lines 28-29) comprising a digestor 2 and a causticizer 7 (Col. 3, line 54-Col. 4, line 4; Fig. 1). Spontak fruther discloses the Kraft process is the most common process used for the production of pulp and paper (Col. 1, lines 10-11).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kiiskila to incorporate the teachings of Spontak wherein a pulping system comprises a pulp digester and the recovery system comprises a causticizer, because the Kraft pulping process is the most common pulping process, as recognized by Spontak (Col. 1, lines 10-11).
Kiiskila is silent to an arrangement configured to introduce at least a portion of the nitrogen containing scrubber liquid from the nitrogen oxide scrubber into the causticizer and/or the pulp digester.
Suchak discloses oxidation of nitrogen oxides resulting in nitrogen trioxide and dinitrogen pentoxide which can be easily absorbed and retain in aqueous medium of a scrubber [0026]. Suchak further discloses the by-product of reaction in the scrubber (nitrate) (aka a nitrogen containing scrubber liquid) is a beneficial effluent for digesting organic impurities in wastewater treatment facilities [0059].
Suchak is silent to using the scrubbing liquid in the digester of a pulp mill.
However, Hale discloses the influent waste stream of a wastewater treatment facility may be high in cellulose materials [0003].
A pulp mill digester digests a cellulosic raw material (See pg. 10 of the Specification of the present application).
Kaverzneva discloses nitrogen oxides are capable of breaking down cellulose (Mechanism on pg. 319).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify Kiiskila to incorporate the teachings of Suchak, Hale, and Kaverzneva to provide an arrangement configured to introduce at least a portion of the nitrogen containing scrubber liquid from the nitrogen oxide scrubber into the pulp digester, because the nitrogen containing scrubber liquid is a beneficial effluent for digesting organic impurities in wastewater treatment facilities, as recognized by Suchak [0059], and wastewater includes cellulose, as recognized by Hale [0003], and nitrogen oxide is known to break down cellulose, as recognized by Kaverzneva (pg. 319).
Response to Arguments
Applicant’s arguments, see "Remarks", pg. 6, par. 1-2, filed 12 September 2025, with respect to the rejection(s) of claim(s) 1-9 under Kiiskila (US 6,146,604) and Spontak (US 5,635,027) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Kiiskila (US 6,146,604) in view of Suchak (US 2012/0076716) and Hale (US 2005/0137332) and Kaverzneva (“Mechanism of the Oxidation of Cellulose with Nitrogen Oxides”).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SLONE ELZABETH SIMKINS whose telephone number is (571)272-3214. The examiner can normally be reached Monday - Friday 8:30AM-4:30PM.
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/S.E.S./Examiner, Art Unit 1735
/PAUL A WARTALOWICZ/Primary Examiner, Art Unit 1735