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 12/16/2025 has been entered. Claims 1-5, 7-30 and 32-33 are pending in this application and examined herein. Claims 1, 8, 11, 17, 26, and 33 are amended. Claims 6 and 31 are cancelled.
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.
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, 7-8, 11-16, 26-30, and 32-33 are rejected under 35 U.S.C. 103 as being unpatentable over Despen et al. (US 20120285080 A1, listed in IDS filed 13 December 2021) in view of Claflin (US 3928023 A, cited in Office Action dated 03/06/2023), Ogorzaly (US 2742353 A), and Metius (US 8685136 B2, cited in Office Action dated 03/06/2023).
Regarding claim 1, Despen teaches high-carbon biogenic reagents and uses thereof (Title), where carbon containing biomass is pyrolyzed to generate pyrolyzed solids, and condensable vapors and non-condensable gases [0012-0019], where a high carbon biogenic reagent is recovered comprising at least a portion of the pyrolyzed solids (i.e., providing a biomass feedstock pyrolyzing the biomass feedstock, thereby generating a biogenic reagent and a pyrolysis off-gas) [0019]. Despen teaches wherein the biogenic reagent comprises carbon [0071] and that the pyrolysis produces non-condensable gases, such as carbon monoxide, hydrogen, carbon dioxide, and methane (i.e., wherein the pyrolysis offgas comprises hydrogen or carbon monoxide) [0372]. Despen teaches the high-carbon biogenic reagent may be used as a carbon-based taconite pellet addition product [0565], where taconite (which comprises iron oxides hematite and magnetite) is ground into a fine powder and pelletized for use in iron or steelmaking (i.e., obtaining a metal ore, wherein the metal ore comprises a metal oxide and the metal ore is in particulate form) [0565-0567]. Despen teaches the pellets may be combined with the high-carbon biogenic reagent when charged to a furnace, or the reagent may be incorporated with the iron ore during the pelletizing (i.e., combining the carbon with the metal ore, thereby generating a carbon-metal ore particulate) [0566-0567]. Despen teaches the pellets may be processed in a blast furnace to produce iron [0567], where the reaction of iron oxides to form iron is a reduction reaction (i.e., a process for reducing a metal ore, chemically reducing the metal oxide).
Despen does not teach wherein the chemically reducing is achieved using the pyrolysis off-gas.
Claflin teaches a method of treating off gases from iron processes (Title), where a blast furnace is charged with burden made up of metal bearing materials such as pellets, and limestone and coke, where metal oxides are reduced to metallic form (Col. 11 lines 28-31), where the metal oxide may be iron oxide (Col. 1 lines 45-46) therefore, Despen and Claflin are analogous to the instant application as both are directed to processes involving production of iron in blast furnaces. Claflin teaches in addition to reducing gas produced in the furnace from blasting air or oxygen enriched air into the furnace and reacting with the furnace burden coke and auxiliary fuels such as natural gas, coke, coal, or fuel oil (Col. 5 lines 38-59), reducing gas is added to the blast furnace (Col. 6 lines 22-29), which reduces the amount of coke and limestone needed to reduce the metal (Col. 7 lines 2-4, Col. 12 lines 3-5), as much of the heat required is derived from other sources (Col. 8 lines 36-44). Claflin teaches the introduction of reducing gas in second and third zones also results in greater reduction of the iron ore than in usual blast furnace operation (Col. 6 line 65 – Col. 7 line 4). Claflin teaches the reducing gas introduced into the second and third zones are CO and H2 (Col. 9 lines 22-36).
Claflin teaches a gas converter 54 which reduces CO2 and H2O in off gases to CO and H2 reducing gases respectively, which are injected into the blast furnace 45 (Col. 7 lines 53-64, Col. 9 lines 28-36, Fig. 2), where the converter may receive gases containing substantial amounts of carbon dioxide, carbon monoxide, and water vapor (Col. 7 line 64 Col. 8 line 3). Claflin teaches the converter may also receive off gases from other unit operations, such as a basic oxygen furnace (Col. 10 lines 53-61).
Because Despen is silent with respect to a suitable blast furnace to utilize the taconite pellets produced, in order to carry out the invention of Despen one of ordinary skill in the art would necessarily look to the art for a reference teaching a blast furnace suitable for use within the process of Despen, such as the blast furnace capable of charging with pellets taught by Claflin.
Further, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added the pyrolysis off-gas generated during by Despen to the gas converter of Claflin to convert CO2 in the pyrolysis gas into CO reducing gas which is fed to the blast furnace, as Claflin teaches the converter is suited to receive off gases from other unit operations, and as Claflin teaches introducing CO and H2 reducing gases produced from outside the blast furnace to achieve greater reduction of metal and reduces the amount of carbonaceous material and limestone needed to operate the blast furnace, which would be recognized by one of ordinary skill to improve the purity and amount of iron produced, and decrease the cost of carbonaceous material and limestone, reducing costs and improving profitability of the process.
Despen teaches the process may further include thermal oxidation (i.e., combustion) of at least a portion of the condensable and non-condensable vapors with an oxygen-containing gas [0032], and the pyrolysis produces non-condensable gases such as carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), and methane (CH4) [0372], but does not teach wherein the chemically reducing indirectly utilizes the pyrolysis off-gas by first partially oxidizing the pyrolysis off-gas, thereby generating a reducing gas.
Metius teaches a system and method for reducing iron oxide to metallic iron using coke oven gas and oxygen steelmaking furnace gases (Title) where COG (coke oven gas) comprising CO and H2, as well as CH4 and other complex hydrocarbons, is processed by partial combustion (partial oxidizing) to convert the CH4 and other complex hydrocarbons into CO and H2, where the processed gas can be added to a reducing gas stream for reducing iron oxide in a furnace (Col. 1 lines 42-48, Col. 2 lines 7-18). Therefore, Despen and Metius are analogous to the instant application as both relate to combustion of gas mixtures containing CO, H2, CH4, and other hydrocarbons.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have performed partial oxidation to form CO and H2 from CH4 and complex hydrocarbons as taught by Metius on at least a portion of the non-condensable vapors (i.e., the pyrolysis off-gas) comprising CH4 of Despen before introducing them to the converter of the blast furnace of Claflin, as doing so would produce more CO and H2 reducing gases which can be used to reduce iron oxide as taught by Metius, predictably increasing how much of the iron ore is reduced in the furnace.
Claflin teaches the use of carbonaceous reducing agent in the gas converter (Col. 9 lines 30-31), such as non-coking coal (Col. 10 lines 39-40), but does not teach which carbonaceous reducing agents may be used besides non-coking coal.
Ogorzaly teaches an iron ore reduction process (Title), where iron ore is reduced by burning carbonaceous material to produce reducing gas and heat for the reaction (Col. 1 lines 15-21), where the gas from the reduction zone corresponds to blast furnace gas (Col. 4 lines 9-10), thus Ogorzaly and Despen are analogous to the instant application as both are directed to processes of reducing metal ore using reducing gases from carbonaceous material. Ogorzaly teaches the carbonaceous material may be coal, coke, or lignite (Col. 1 lines 70-71), or petroleum coke, charcoal, or peat (Col. 1 line 71).
Because Despen in view of Claflin is silent with respect to which carbonaceous material may be used in the gas converter besides non-coking coal, in order to carry out the invention of Claflin one of ordinary skill in the art would necessarily look to the art for a reference teaching carbonaceous reducing agents suitable for use within the process of Claflin, such as those of petroleum coke, charcoal, or peat taught by Ogorzaly. As Claflin and Ogorzaly both relate to carbonaceous materials used to produce reducing gases, one of ordinary skill would be motivated to use the carbonaceous materials of Ogorzaly. As petroleum coke, charcoal, and peat are not coal, Despen in view of Ogorzaly teaches wherein the process does not utilize coal.
Regarding claim 8, Despen does not teach wherein the chemically reducing co-utilizes a reducing gas obtained from gasification, partial oxidation, or steam reforming of light hydrocarbons.
Claflin teaches that auxiliary fuels such as natural gas (i.e., light hydrocarbons not derived from coal) are added to the blast furnace in the primary zone (Claflin: Col. 5 lines 45-50), and that gaseous hydrocarbons form CO and H2 therein (Claflin: Col. 6 lines 27-28), known reducing gases which partake in reducing the iron oxides (wherein the chemically reducing co-utilizes a reducing gas made from light hydrocarbons; Col. 4 lines 53-61). The Examiner notes as CO is produced from incomplete combustion of fuels when there is a stoichiometric excess of fuel relative to the amount of oxygen (i.e. partial oxidation), the light hydrocarbons are partially oxidized to form the reducing gases in the primary zone. Claflin teaches adding auxiliary gases helps replace reducing gas lost and reduce the flame temperature (Col. 3 lines 62-67), where increases in flame temperature can cause premature melting of iron oxide, increasing coke usage (Col. 4 lines 34-40).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added natural gas as an auxiliary fuel as taught by Claflin to the blast furnace of Despen as doing so would partially oxidize the auxiliary fuel to supply additional reducing gas and help prevent premature melting of iron oxide by maintaining a low flame temperature, lowering coke usage.
Regarding claim 11, Despen teaches high-carbon biogenic reagents and uses thereof (Title), where carbon containing biomass is pyrolyzed to generate pyrolyzed solids, and condensable vapors and non-condensable gases [0012-0019], where a high carbon biogenic reagent is recovered comprising at least a portion of the pyrolyzed solids (providing a biomass feedstock pyrolyzing the biomass feedstock, thereby generating a biogenic reagent and a pyrolysis off-gas; [0019]). Despen teaches the high-carbon biogenic reagent may contain at least 55 wt % carbon on a dry basis, such as at least 55 wt. %, 60 wt. %, 65 wt. %, 70 wt. %, 75 wt. %, 80 wt %, 90 wt %, 95 wt %, or more carbon on a dry basis (wherein the biogenic reagent comprises carbon; [0071]) and that the pyrolysis produces non-condensable gases, such as carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), and methane (CH4) (wherein the pyrolysis off-gas comprises hydrocarbons; [0372]). Despen teaches the high-carbon biogenic reagent may be used as a carbon-based taconite pellet addition product [0565], where taconite (which comprises iron oxides hematite and magnetite) is ground into a fine powder and pelletized for use in iron or steelmaking (obtaining a metal ore, wherein the metal ore comprises a metal oxide and the metal ore is in particulate form; [0565-0567]). Despen teaches the pellets may be combined with the high-carbon biogenic reagent when charged to a furnace, or the reagent may be incorporated with the iron ore during the pelletizing (combining the carbon with the metal ore, thereby generating a carbon-metal ore particulate; [0566-0567]). Despen teaches the pellets may be processed in a blast furnace to produce iron [0567], where the reaction of iron oxides to form iron is a reduction reaction (process for reducing a metal ore, chemically reducing the metal oxide). Despen teaches the process may further include thermal oxidation of at least a portion of the non-condensable vapors with an oxygen-containing gas, where heat produced from the thermal oxidation may be utilized, at least in part, for drying the feedstock or to heat a substantially inert gas before entering one of the zones or reactors, such as the pyrolysis zone (oxidizing the pyrolysis gas, thereby generating heat [0032]). As Despen uses the heat produced to heat gas before it is introduced to the pyrolysis reactors, the heat produced from pyrolysis makes up some of the heat needed for the pyrolysis steps, reading on wherein the pyrolyzing uses the heat.
Despen does not teach pyrolysis of the non-condensable vapor to be partial, or wherein a reducing gas is generated by partial oxidation which achieves the chemically reducing.
Claflin teaches a method of treating off gases from iron processes (Title), where a blast furnace is charged with burden made up of metal bearing materials such as pellets, and limestone and coke, where metal oxides are reduced to metallic form (Col. 11 lines 28-31), where the metal oxide may be iron oxide (Col. 1 lines 45-46) therefore, Despen and Claflin are analogous to the instant application as both are directed to processes involving production of iron in blast furnaces. Claflin teaches in addition to reducing gas produced in the furnace from blasting air or oxygen enriched air into the furnace and reacting with the furnace burden coke and auxiliary fuels such as natural gas, coke, coal, or fuel oil (Col. 5 lines 38-59), reducing gas is added to the blast furnace (Col. 6 lines 22-29), which reduces the amount of coke and limestone needed to reduce the metal (Col. 7 lines 2-4, Col. 12 lines 3-5), as much of the heat required is derived from other sources (Col. 8 lines 36-44). Claflin teaches the introduction of reducing gas in second and third zones also results in greater reduction of the iron ore than in usual blast furnace operation (Col. 6 line 65 – Col. 7 line 4). Claflin teaches the reducing gas introduced into the second and third zones are CO and H2 (Col. 9 lines 22-36).
Claflin teaches a gas converter 54 which reduces CO2 and H2O in off gases to CO and H2 reducing gases respectively, which are injected into the blast furnace 45 (Col. 7 lines 53-64, Col. 9 lines 28-36, Fig. 2), where the converter may receive gases containing substantial amounts of carbon dioxide, carbon monoxide, and water vapor (Col. 7 line 64 Col. 8 line 3). Claflin teaches the converter may also receive off gases from other unit operations, such as a basic oxygen furnace (Col. 10 lines 53-61).
Because Despen is silent with respect to a suitable blast furnace to utilize the taconite pellets produced, in order to carry out the invention of Despen one of ordinary skill in the art would necessarily look to the art for a reference teaching a blast furnace suitable for use within the process of Despen, such as the blast furnace capable of charging with pellets taught by Claflin.
Further, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added the pyrolysis off-gas generated during by Despen to the gas converter of Claflin to convert CO2 in the pyrolysis gas into CO reducing gas which are fed to the blast furnace, as Claflin teaches the converter is suited to receive off gases from other unit operations, and as Claflin teaches introducing CO and H2 reducing gases produced from outside the blast furnace to achieve greater reduction of metal and reduces the amount of carbonaceous material and limestone needed to operate the blast furnace, which would be recognized by one of ordinary skill to improve the purity and amount of iron produced, and decrease the cost of carbonaceous material and limestone, reducing costs and improving profitability of the process.
Despen teaches does not teach partial oxidizing of pyrolysis off-gas, or wherein a reducing gas is generated by the partial oxidation which achieves the chemically reducing.
Metius teaches a system and method for reducing iron oxide to metallic iron using coke oven gas and oxygen steelmaking furnace gases (Title) where COG (coke oven gas) comprising CO and H2, as well as CH4 and other complex hydrocarbons, is processed by partial combustion (partial oxidizing) to convert the CH4 and other complex hydrocarbons into CO and H2, where the processed gas can be added to a reducing gas stream for reducing iron oxide in a furnace (Col. 1 lines 42-48, Col. 2 lines 7-18). Therefore, Despen and Metius are analogous to the instant application as both relate to combustion of gas mixtures containing CO, H2, CH4, and other hydrocarbons.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have performed partial oxidation to form CO and H2 from CH4 and complex hydrocarbons as taught by Metius on at least a portion of the non-condensable vapors (i.e., the pyrolysis off-gas) comprising CH4 of Despen before introducing them to the converter of the blast furnace of Claflin, as doing so would produce more CO and H2 reducing gases which can be used to reduce iron oxide as taught by Metius, predictably increasing how much of the iron ore is reduced in the furnace.
Claflin teaches the use of carbonaceous reducing agent in the gas converter (Col. 9 lines 30-31), such as non-coking coal (Col. 10 lines 39-40), but does not teach which carbonaceous reducing agents may be used besides non-coking coal.
Ogorzaly teaches an iron ore reduction process (Title), where iron ore is reduced by burning carbonaceous material to produce reducing gas and heat for the reaction (Col. 1 lines 15-21), where the gas from the reduction zone corresponds to blast furnace gas (Col. 4 lines 9-10), thus Ogorzaly and Despen are analogous to the instant application as both are directed to processes of reducing metal ore using reducing gases from carbonaceous material. Ogorzaly teaches the carbonaceous material may be coal, coke, or lignite (Col. 1 lines 70-71), or petroleum coke, charcoal, or peat (Col. 1 line 71).
Because Despen in view of Claflin is silent with respect to which carbonaceous material may be used in the gas converter besides non-coking coal, in order to carry out the invention of Claflin one of ordinary skill in the art would necessarily look to the art for a reference teaching carbonaceous reducing agents suitable for use within the process of Claflin, such as those of petroleum coke, charcoal, or peat taught by Ogorzaly. As Claflin and Ogorzaly both relate to carbonaceous materials used to produce reducing gases, one of ordinary skill would be motivated to use the carbonaceous materials of Ogorzaly. As petroleum coke, charcoal, and peat are not coal, Despen in view of Ogorzaly teaches wherein the process does not utilize coal.
Regarding claim 26, Despen teaches high-carbon biogenic reagents and uses thereof (Title), where carbon containing biomass is pyrolyzed to generate pyrolyzed solids, and condensable vapors and non-condensable gases [0012-0019], where a high carbon biogenic reagent is recovered comprising at least a portion of the pyrolyzed solids (providing a biomass feedstock, pyrolyzing the biomass feedstock, thereby generating a biogenic reagent and a pyrolysis off-gas; [0019]). Despen teaches the high-carbon biogenic reagent may contain at least 55 wt % carbon on a dry basis, such as at least 55 wt. %, 60 wt. %, 65 wt. %, 70 wt. %, 75 wt. %, 80 wt %, 90 wt %, 95 wt %, or more carbon on a dry basis (wherein the biogenic reagent comprises carbon; [0071]) and that the pyrolysis produces non-condensable gases, such as carbon monoxide, hydrogen, carbon dioxide, and methane (wherein the pyrolysis offgas comprises hydrogen or carbon monoxide; [0372]). Despen teaches the high-carbon biogenic reagent may be used as a carbon-based taconite pellet addition product [0565], where taconite (which comprises iron oxides hematite and magnetite) is ground into a fine powder and pelletized for use in iron or steelmaking (obtaining a metal ore, wherein the metal ore comprises a metal oxide; [0565-0567]). Despen teaches the pellets may be combined with the high-carbon biogenic reagent when charged to a furnace, or the reagent may be incorporated with the iron ore during the pelletizing (combining the carbon with the metal ore, thereby generating a carbon-metal ore particulate; [0566-0567]). Despen teaches the pellets may be processed in a blast furnace to produce iron [0567], where the reaction of iron oxides to form iron is a reduction reaction (process for treating a metal ore, chemically producing an elemental metal from the metal oxide).
Despen does not teach wherein the chemically producing is achieved using the pyrolysis off-gas.
Claflin teaches a method of treating off gases from iron processes (Title), where a blast furnace is charged with burden made up of metal bearing materials such as pellets, and limestone and coke, where metal oxides are reduced to metallic form (Col. 11 lines 28-31), where the metal oxide may be iron oxide (Col. 1 lines 45-46) therefore, Despen and Claflin are analogous to the instant application as both are directed to processes involving production of iron in blast furnaces. Claflin teaches in addition to reducing gas produced in the furnace from blasting air or oxygen enriched air into the furnace and reacting with the furnace burden coke and auxiliary fuels such as natural gas, coke, coal, or fuel oil (Col. 5 lines 38-59), reducing gas is added to the blast furnace (Col. 6 lines 22-29), which reduces the amount of coke and limestone needed to reduce the metal (Col. 7 lines 2-4, Col. 12 lines 3-5), as much of the heat required is derived from other sources (Col. 8 lines 36-44). Claflin teaches the introduction of reducing gas in second and third zones also results in greater reduction of the iron ore than in usual blast furnace operation (Col. 6 line 65 – Col. 7 line 4). Claflin teaches the reducing gas introduced into the second and third zones are CO and H2 (Col. 9 lines 22-36).
Claflin teaches a gas converter 54 which reduces CO2 and H2O in off gases to CO and H2 reducing gases respectively, which are injected into the blast furnace 45 (Col. 7 lines 53-64, Col. 9 lines 28-36, Fig. 2), where the converter may receive gases containing substantial amounts of carbon dioxide, carbon monoxide, and water vapor (Col. 7 line 64 Col. 8 line 3). Claflin teaches the converter may also receive off gases from other unit operations, such as a basic oxygen furnace (Col. 10 lines 53-61).
Because Despen is silent with respect to a suitable blast furnace to utilize the taconite pellets produced, in order to carry out the invention of Despen one of ordinary skill in the art would necessarily look to the art for a reference teaching a blast furnace suitable for use within the process of Despen, such as the blast furnace capable of charging with pellets taught by Claflin.
Further, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added the pyrolysis off-gas generated during by Despen to the gas converter of Claflin to convert CO2 in the pyrolysis gas into CO and H2 reducing gases which are fed to the blast furnace, as Claflin teaches the converter is suited to receive off gases from other unit operations, and as Claflin teaches introducing CO and H2 reducing gases produced from outside the blast furnace to achieve greater reduction of metal and reduces the amount of carbonaceous material and limestone needed to operate the blast furnace, which would be recognized by one of ordinary skill to improve the purity and amount of iron produced, and decrease the cost of carbonaceous material and limestone, reducing costs and improving profitability of the process.
Despen teaches the process may further include thermal oxidation (i.e., combustion) of at least a portion of the condensable and non-condensable vapors with an oxygen-containing gas [0032], and the pyrolysis produces non-condensable gases such as carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), and methane (CH4) [0372], but does not teach partially oxidizing pyrolysis off-gas thereby generating a reducing gas.
Metius teaches a system and method for reducing iron oxide to metallic iron using coke oven gas and oxygen steelmaking furnace gases (Title) where COG (coke oven gas) comprising CO and H2, as well as CH4 and other complex hydrocarbons, is processed by partial combustion (partial oxidizing) to convert the CH4 and other complex hydrocarbons into CO and H2 (i.e., generating reducing gas) where the processed gas can be added to a reducing gas stream for reducing iron oxide in a furnace (Col. 1 lines 42-48, Col. 2 lines 7-18).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have performed partial oxidation to form CO and H2 from CH4 and complex hydrocarbons as taught by Metius on the non-condensable vapors (i.e., the pyrolysis off-gas) of Despen before introducing them to the converter of the blast furnace of Claflin, as doing so would produce more CO and H2 reducing gases which can be used to reduce iron oxide as taught by Metius (i.e., chemically producing elemental metal using the reducing gas), predictably increasing how much of the iron ore is reduced in the furnace.
Claflin teaches the use of carbonaceous reducing agent in the gas converter (Col. 9 lines 30-31), such as non-coking coal (Col. 10 lines 39-40), but does not teach which carbonaceous reducing agents may be used besides non-coking coal.
Ogorzaly teaches an iron ore reduction process (Title), where iron ore is reduced by burning carbonaceous material to produce reducing gas and heat for the reaction (Col. 1 lines 15-21), where the gas from the reduction zone corresponds to blast furnace gas (Col. 4 lines 9-10), thus Ogorzaly and Despen are analogous to the instant application as both are directed to processes of reducing metal ore using reducing gases from carbonaceous material. Ogorzaly teaches the carbonaceous material may be coal, coke, or lignite (Col. 1 lines 70-71), or petroleum coke, charcoal, or peat (Col. 1 line 71).
Because Despen in view of Claflin is silent with respect to which carbonaceous material may be used in the gas converter besides non-coking coal, in order to carry out the invention of Claflin one of ordinary skill in the art would necessarily look to the art for a reference teaching carbonaceous reducing agents suitable for use within the process of Claflin, such as those of petroleum coke, charcoal, or peat taught by Ogorzaly. As Claflin and Ogorzaly both relate to carbonaceous materials used to produce reducing gases, one of ordinary skill would be motivated to use the carbonaceous materials of Ogorzaly. As petroleum coke, charcoal, and peat are not coal, Despen in view of Ogorzaly teaches wherein the process does not utilize coal.
Regarding claim 33, Despen does not teach wherein the chemically reducing co-utilizes a reducing gas obtained from gasification, partial oxidation, or steam reforming of light hydrocarbons.
Claflin teaches that auxiliary fuels such as natural gas (i.e., light hydrocarbons not derived from coal) are added to the blast furnace in the primary zone (Col. 5 lines 45-50), and that gaseous hydrocarbons form CO and H2 therein (Claflin: Col. 6 lines 27-28), known reducing gases which partake in reducing the iron oxides (wherein the chemically reducing co-utilizes a reducing gas made from light hydrocarbons; Col. 4 lines 53-61). The Examiner notes as CO is produced from incomplete combustion of fuels when there is a stoichiometric excess of fuel relative to the amount of oxygen (i.e. partial oxidation), the light hydrocarbons are partially oxidized to form the reducing gases in the primary zone. Claflin teaches adding auxiliary gases helps replace reducing gas lost and reduce the flame temperature (Col. 3 lines 62-67), where increases in flame temperature can cause premature melting of iron oxide, increasing coke usage (Col. 4 lines 34-40).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have added natural gas as an auxiliary fuel as taught by Claflin to the blast furnace of Despen as doing so would partially oxidize the auxiliary fuel to supply additional reducing gas and help prevent premature melting of iron oxide by maintaining a low flame temperature, lowering coke usage.
Claims 2-5, 7, 12-16, 27-30, and 32 remain rejected as set forth in the Office Action dated 03/06/2023. Claims 2-5, 7, 12-16, 27-30, and 32 have not been amended since that time, and the previously presented grounds of rejection set forth how the prior art teaches or suggests all of the limitations of the claims.
Claim 9 is rejected under 35 U.S.C. 103 as being unpatentable over Despen in view of Claflin, Metius, and Ogorzaly as applied to claim 1 above, and further in view of Mahony (US 3235374 A, cited in Office Action mailed 03/06/2023).
Claim 9 remains rejected as set forth in the Office Action dated 03/06/2023. Claim 9 has not been amended since that time, and the previously presented grounds of rejection set forth how the prior art teaches or suggests all of the limitations of the claims.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Despen in view of Claflin, Metius, and Ogorzaly as applied to claim 1 above, and further in view of Sugitatsu (US 6797034 B2).
Claim 10 remains rejected as set forth in the Office Action dated 03/06/2023. Claim 10 has not been amended since that time, and the previously presented grounds of rejection set forth how the prior art teaches or suggests all of the limitations of the claims.
Claims 17-23 are rejected under 35 U.S.C. 103 as being unpatentable over Despen in view of Claflin and Ogorzaly.
Regarding claim 17, Despen teaches high-carbon biogenic reagents and uses thereof (Title), where carbon containing biomass is pyrolyzed to generate pyrolyzed solids, and condensable vapors and non-condensable gases [0012-0019], where a high carbon biogenic reagent is recovered comprising at least a portion of the pyrolyzed solids (i.e., providing a biomass feedstock, pyrolyzing the biomass feedstock, thereby generating a biogenic reagent) [0019]. Despen teaches wherein the biogenic reagent comprises carbon [0071]. Despen teaches the high-carbon biogenic reagent may be used as a carbon-based taconite pellet addition product [0565], where taconite (which comprises iron oxides hematite and magnetite) is ground into a fine powder and pelletized for use in iron or steelmaking (i.e., obtaining a metal ore, wherein the metal ore comprises a metal oxide and the metal ore is in particulate form) [0565-0567]. Despen teaches the pellets may be combined with the high-carbon biogenic reagent when charged to a furnace, or the reagent may be incorporated with the iron ore during the pelletizing (i.e., combining the carbon with the metal ore, thereby generating a carbon-metal ore particulate) [0566-0567]. Despen teaches the pellets may be processed in a blast furnace to produce iron [0567], where the reaction of iron oxides to form iron is a reduction reaction (process for reducing a metal ore, chemically reducing the metal oxide). Despen teaches the high-carbon biogenic reagents may be partially oxidized or steam-reformed to produce syngas (a mixture of CO and H2) (i.e., generating a reducing gas from partial oxidation or steam reforming of the biogenic reagent) [0550], but does not teach wherein the chemically reducing is achieved using the reducing gas.
Claflin teaches a method of treating off gases from iron processes (Title), where a blast furnace is charged with burden made up of metal bearing materials such as pellets, and limestone and coke, where metal oxides are reduced to metallic form (Col. 11 lines 28-31). Claflin teaches in addition to reducing gas produced in the furnace from blasting air or oxygen enriched air into the furnace and reacting with the furnace burden coke and auxiliary fuels such as natural gas, coke, coal, or fuel oil (Col. 5 lines 38-59), reducing gas is added to the blast furnace in second and third zones (Col. 6 lines 22-29), which reduces the amount of coke and limestone needed to reduce the metal (Col. 7 lines 2-4, Col. 12 lines 3-5), as much of the heat required is derived from other sources (Col. 8 lines 36-44). Claflin teaches the introduction of reducing gas in second and third zones also results in greater reduction of the iron ore than in usual blast furnace operation (Col. 6 line 65 – Col. 7 line 4). Claflin teaches the reducing gas introduced into the second and third zones are CO and H2 (Col. 9 lines 22-36).
Because Despen is silent with respect to a suitable blast furnace to utilize the taconite pellets produced, in order to carry out the invention of Despen one of ordinary skill in the art would necessarily look to the art for a reference teaching a blast furnace suitable for use within the process of Despen, such as the blast furnace capable of charging with pellets taught by Claflin.
Further, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have used the CO and H2 produced by partial oxidation or steam reforming of the biogenic reagent of Despen as reducing gases added to the blast furnace as taught by Claflin, as Claflin teaches introducing CO and H2 to the blast furnace to achieve greater reduction of metal and reduces the amount of carbonaceous material and limestone needed to operate the blast furnace, which would be recognized by one of ordinary skill to improve the purity and amount of iron produced, and decrease the cost of carbonaceous material and limestone, reducing costs and improving profitability of the process.
Claflin teaches the use of carbonaceous reducing agent in the gas converter (Col. 9 lines 30-31), such as non-coking coal (Col. 10 lines 39-40), but does not teach which carbonaceous reducing agents may be used besides non-coking coal.
Ogorzaly teaches an iron ore reduction process (Title), where iron ore is reduced by burning carbonaceous material to produce reducing gas and heat for the reaction (Col. 1 lines 15-21), where the gas from the reduction zone corresponds to blast furnace gas (Col. 4 lines 9-10), thus Ogorzaly and Despen are analogous to the instant application as both are directed to processes of reducing metal ore using reducing gases from carbonaceous material. Ogorzaly teaches the carbonaceous material may be coal, coke, or lignite (Col. 1 lines 70-71), or petroleum coke, charcoal, or peat (Col. 1 line 71).
Because Despen in view of Claflin is silent with respect to which carbonaceous material may be used in the gas converter besides non-coking coal, in order to carry out the invention of Claflin one of ordinary skill in the art would necessarily look to the art for a reference teaching carbonaceous reducing agents suitable for use within the process of Claflin, such as those of petroleum coke, charcoal, or peat taught by Ogorzaly. As Claflin and Ogorzaly both relate to carbonaceous materials used to produce reducing gases, one of ordinary skill would be motivated to use the carbonaceous materials of Ogorzaly. As petroleum coke, charcoal, and peat are not coal, Despen in view of Ogorzaly teaches wherein the process does not utilize coal.
Claims 18-23 remain rejected as set forth in the Office Action dated 03/06/2023. Claims 18-23 have not been amended since that time, and the previously presented grounds of rejection set forth how the prior art teaches or suggests all of the limitations of the claims.
Claim 24 is rejected under 35 U.S.C. 103 as being unpatentable over Despen in view of Claflin and Ogorzaly as applied to claim 17 above, and further in view of Mahony.
Claim 24 remains rejected as set forth in the Office Action dated 03/06/2023. Claim 24 has not been amended since that time, and the previously presented grounds of rejection set forth how the prior art teaches or suggests all of the limitations of the claims.
Claim 25 is rejected under 35 U.S.C. 103 as being unpatentable over Despen in view of Claflin and Ogorzaly as applied to claim 17 above, and further in view of Sugitatsu.
Claim 25 remains rejected as set forth in the Office Action dated 03/06/2023. Claim 25 has not been amended since that time, and the previously presented grounds of rejection set forth how the prior art teaches or suggests all of the limitations of the claims.
Response to Arguments
Applicant's arguments filed 12/16/2025 have been fully considered with the following effect:
Applicant’s arguments with respect to the rejections of claims 1, 11, 17, and 26 under 35 USC 103 as rejected by Despen in view of Claflin and Metius that Claflin does not teach the process to not utilize coal (see pg. 11 of remarks), have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground of rejection is made in view of Ogorzaly as necessitated by amendment.
Applicant’s argument with respect to the rejections of claims 1, 11, and 26 under 35 USC 103 that Despen in view of Claflin does not teach partial oxidation (see pg. 11-12 of remarks) have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground of rejection is made in view of Metius as necessitated by amendment.
Regarding Applicant’s argument that Metius teaches methane reforming rather than partial oxidation, and therefore teaches total combustion of the COG stream (see pg. 12 of remarks), the Examiner respectfully disagrees.
While as Applicant notes, Metius may disclose methane reforming, Metius is relied upon to teach partial oxidation of a stream comprising CO, H2, CH4, and other complex hydrocarbons (analogous pyrolysis off-gas), not for its disclosure of methane reforming, which as noted by Applicant is not partial oxidation.
Metius discloses an exemplary oxidation reaction at Col. 6 lines 50-61, where combustible gases such as CO, H2, and CH4 remain in the product gases for both 1.7 parts oxygen and 2 parts oxygen, and where concentrations of H2 (a reducing gas) are increased relative to the starting COG, therefore the “partial combustion” of Metius comprises partial oxidation which generates reducing gases as claimed.
As Applicant notes, Metius teaches “COG with or without complex hydrocarbons may also be used… to enrich the ultimate reducing gas stream”, however as Metius as noted above teaches removing complex hydrocarbons by partially oxidizing them (and leaving the product gases in the clean COG, as shown in Fig. 2 where only clean COG exits the partial oxidation reactor), the reducing gases produced by partial oxidation as part of the clean COG are used to enrich the ultimate reducing gas stream.
Regarding Applicant’s argument that there is no teaching or suggestion that the reducing gas of Metius is made from partially oxidizing a biomass-pyrolysis off-gas or that the reducing gas is specifically used to chemically reduce a metal oxide (see pg. 12 of remarks), the Examiner respectfully disagrees
As Applicant notes Metius alone does not teach a reducing gas made from partial oxidation of biomass-pyrolysis off-gas, instead, it is the Examiner’s position that one of ordinary skill, starting from Despen which teaches producing a pyrolysis off-gas stream comprising CO and H2 (both reducing gases) and CO2, and CH4, and also teaches producing iron using a biogenic reagent as a reductant in a blast furnace; when taken in view of Claflin, which teaches adding reducing gases comprising CO and H2 to a blast furnace for producing iron, one of ordinary skill would add the pyrolysis off-gases comprising CO and H2 reducing gases to a blast furnace for producing iron. Further, one of ordinary skill seeing that Metius teaches taking a COG stream comprising CO and H2 reducing gases, and CO2 and CH4 (the same compounds as in the pyrolysis gas stream of Despen) and partially oxidizing it to increase its reducing gas content, would take the pyrolysis-off gas stream with a similar composition to partial oxidation to increase its reducing gas content before adding it to a blast furnace as a reducing gas stream according to Claflin.
Claflin teaches the reducing gases are specifically used to reduce metal oxide in a blast furnace, Claflin at Col. 12 lines 54-66 teaches “Re-formed gaseous product is taken off… of the converter 54… to blast furnace bustle pipes 35 and 36… By control of the three furnace zones of blast furnace 45… a major portion of the iron oxide component… is reduced to metallic iron”.
Regarding Applicant’s argument that each claim requires combining the carbon with the metal ore, thereby generating a carbon-metal ore particulate, which is not taught by Claflin or Metius (see pg. 12-13 of remarks), the Examiner notes this limitation is instead taught by primary reference Despen. As Despen already teaches forming carbon-metal ore particulates and feeding them to furnaces to produce iron (Despen: [0567]), there is no need to e.g., replace coke used in the blast furnace of Claflin with biocarbon; as Despen already teaches using carbon-metal ore particulates and Claflin is only relied upon to teach a suitable blast furnace apparatus to use as the blast furnace of Despen and to further use the pyrolysis off-gases of Despen to assist reducing the carbon-metal ore particulates in the blast furnace as suggested by Claflin as noted above.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning (see pg. 13-14 of remarks), it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). As in the instant case, the combination of references is based on the expected advantages of achieving greater reduction of metal and reducing the amount of carbonaceous material and limestone needed to operate the blast furnace, improving the purity and amount of iron produced, and decreasing cost of carbonaceous material and limestone, reducing costs and improving profitability of the process, all of which are gleaned from Claflin and Metius rather than the instant specification, it would have been obvious to have modified Despen in view of Claflin and Metius as noted above.
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.
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/Keith D. Hendricks/Supervisory Patent Examiner, Art Unit 1733
/NIKOLAS TAKUYA PULLEN/Examiner, Art Unit 1733