# US 8,541,623 B2 · Oxidation method and reactor > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,541,623 B2 - Document ID: US8541623B2 - Status: Granted - Kind: B2 - Application number: 12/984,206 - Filed: 2011-01-04 - Published: 2012-07-05 - Granted: 2013-09-24 - Earliest claimed: 2011-01-04 - Assignees: Linde Aktiengesellschaft - Applicants: Naresh Suchak; Zhixiong Cha; Frank R. Fitch - Inventors: Naresh Suchak; Zhixiong Cha; Frank R. Fitch - Web page: https://patentgrep.com/patent/US8541623B2 ## CPC - F17C 13/001: {Thermal insulation specially adapted for cryogenic vessels (vessels not under pressure with insulation F17C3/02; thermal insulation in general F16L59/00)} - B01J 4/002: {Nozzle-type elements (nozzle-type reactors B01J19/26)} - B01J 10/00: Chemical processes in general for reacting liquid with gaseous media other than in the presence of solid particles, or apparatus specially adapted therefor (B01J19/08 takes precedence; separation, e.g. distillation, also combined with chemical reactions B01D, {e.g. B01D3/009}) - B01J 19/0066: {Stirrers (mixing per se B01F)} - B01J 2219/00108: involving reactant vapours - B01J 2219/00162: controlling the pressure - B01J 2219/00186: controlling the composition of the reactive mixture - B01J 2219/002: inside the reactor - B01J 2219/00231: at the reactor inlet - F17C: VESSELS FOR CONTAINING OR STORING COMPRESSED, LIQUEFIED OR SOLIDIFIED GASES; FIXED-CAPACITY GAS-HOLDERS; FILLING VESSELS WITH, OR DISCHARGING FROM VESSELS, COMPRESSED, LIQUEFIED, OR SOLIDIFIED GASES (storing fluids in natural or artificial cavities or chambers in the earth B65G5/00; construction or assembling of bulk storage containers employing civil-engineering techniques E04H7/00; variable-capacity gas-holders F17B; liquefaction or refrigeration machines, plants, or systems F25) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract A method and apparatus for increasing the concentration of oxygen in the reaction medium present in the oxidation reactor. A volume of aqueous medium from the oxidation reactor is removed and pressurized and oxygen is added to it. The oxygen-rich volume of aqueous medium is then reintroduced into the oxidation reactor at an increased pressure to ensure adequate mixing with the aqueous medium having a lower content of oxygen. ## Claims ### Claim 1 A method for oxidizing a material in an oxidation reactor, wherein said oxidation reactor further comprises an external circulation loop having means to increase the pressure in said external loop comprising the steps of: a) measuring the concentration of oxygen in said oxidation reactor; b) withdrawing a volume of aqueous medium from said oxidation reactor and measuring the concentration of oxygen in said volume; c) feeding oxygen into said volume as a dissolved species and allowing sufficient residence time to achieve a desired concentration of oxygen, wherein the oxygen feed amount is determined by measuring dissolved oxygen in the reactor and its pressure, and measuring the density of the volume and the concentration of oxygen in the ullage; d) feeding said volume back into said oxidation reactor at an elevated pressure and through a venturi device to a liquid distributor; and e) forming a circulation pattern within said oxidation reactor whereby a higher concentration of oxygen is maintained in the aqueous medium at the bottom of said oxidation reactor, and wherein the external circulation loop is maintained at pressure during steps c), d) and e). ### Claim 2 (depends on 1) The method as claimed in claim 1 wherein the amount of oxygen added to said volume is controlled to ensure dissolution of said oxygen. ### Claim 3 (depends on 1) The method as claimed in claim 1 wherein the amount of oxygen added to said volume is determined by a process selected from the group consisting of the flow rate of oxygen leaving said oxidation reactor and the concentration of dissolved oxygen in said oxidation reactor. ### Claim 4 (depends on 1) The method as claimed in claim 1 wherein the amount of oxygen added to said volume is controlled to inhibit formation of free bubbles in said oxidation reactor. ### Claim 5 (depends on 1) The method as claimed in claim 1 wherein the depth at which said volume is added to said liquid distributor is sufficient to provide high back pressure to the flow of said volume. ### Claim 6 (depends on 1) The method as claimed in claim 1 wherein feeding of said volume into said oxidation reactor agitates the contents of said oxidation reactor thereby suspending solids and improving heat transfer in said oxidation reactor. ### Claim 7 A method for increasing the concentration of oxygen in an oxidation reactor comprising the steps: a) withdrawing a volume of aqueous medium from said oxidation reactor and measuring the concentration of oxygen in the volume; b) feeding oxygen as a dissolved species to said volume of aqueous medium and allowing for sufficient residence time to achieve a desired concentration of oxygen, wherein the oxygen feed amount is determined by measuring dissolved oxygen in the reactor and its pressure, and measuring the density of the volume and the concentration of oxygen in the ullage; c) feeding the oxygen-enriched volume of aqueous medium back to said oxidation reactor; and d) mixing said oxygen-enriched volume of aqueous medium into an aqueous medium in said oxidation reactor. ### Claim 8 (depends on 7) The method as claimed in claim 7 wherein said oxygen is fed at an elevated pressure. ### Claim 9 (depends on 7) The method as claimed in claim 7 wherein said oxidation reactor is maintained at ambient pressure. ### Claim 10 (depends on 7) The method as claimed in claim 7 wherein said oxygen-enriched volume of aqueous medium is introduced into said oxidation reactor through a venturi device. ### Claim 11 (depends on 7) The method as claimed in claim 7 wherein the oxygen-enriched volume of aqueous medium is introduced at a depth to provide mixing with said aqueous medium. ### Claim 12 (depends on 7) The method as claimed in claim 7 wherein said oxygen-enriched volume of aqueous medium approaches oxygen saturation. ### Claim 13 (depends on 7) The method as claimed in claim 7 wherein a pump is used to increase the pressure of said oxygen-enriched aqueous medium. ### Claim 14 (depends on 7) The method as claimed in claim 7 wherein said withdrawing of a volume of aqueous medium is performed in a periodic fashion. ### Claim 15 A method for improving the oxidation of reactants in an oxidation reactor comprising the steps: a) withdrawing a volume of aqueous medium from said oxidation reactor; b) feeding oxygen as a dissolved species to said volume of aqueous medium and allowing sufficient residence time to achieve a desired concentration of oxygen, wherein the oxygen feed amount is determined by measuring dissolved oxygen in the reactor and its pressure, and measuring the density of the volume and the concentration of oxygen in the ullage; c) feeding the oxygen-enriched volume of aqueous medium back to said oxidation reactor; and d) mixing said oxygen-enriched volume of aqueous medium into an aqueous medium in said oxidation reactor. ### Claim 16 (depends on 15) The method as claimed in claim 15 wherein said oxygen is fed at an elevated pressure. ### Claim 17 (depends on 15) The method as claimed in claim 15 wherein said oxidation reactor is maintained at ambient pressure. ### Claim 18 (depends on 15) The method as claimed in claim 15 wherein said oxygen-enriched volume of aqueous medium is introduced into said oxidation reactor through a venturi device. ### Claim 19 (depends on 15) The method as claimed in claim 15 wherein the oxygen-enriched volume of aqueous medium is introduced at a depth to provide mixing with said aqueous medium. ### Claim 20 (depends on 15) The method as claimed in claim 15 wherein said oxygen-enriched volume of aqueous medium approaches oxygen saturation. ### Claim 21 (depends on 15) The method as claimed in claim 15 wherein a pump is used to increase the pressure of said oxygen-enriched aqueous medium. ### Claim 22 (depends on 15) The method as claimed in claim 15 wherein said withdrawing of a volume of aqueous medium is performed in a periodic fashion. ### Claim 23 A method for oxidizing an organic material in an oxidation reactor, wherein said oxidation reactor further comprises an external circulation loop having means to increase the pressure in said external loop comprising the steps of: a) measuring the concentration of oxygen in said oxidation reactor; b) withdrawing a volume of organic medium from said oxidation reactor and measuring the concentration of oxygen in said volume; c) feeding oxygen as a dissolved species into said volume and allowing sufficient residence time to achieve a desired concentration of oxygen, wherein the oxygen feed amount is determined by measuring dissolved oxygen in the reactor and its pressure, and measuring the density of the volume and the concentration of oxygen in the ullage; d) feeding said volume back into said oxidation reactor at an elevated pressure and through a venturi device to a liquid distributor; and e) forming a circulation pattern within said oxidation reactor whereby a higher concentration of oxygen is maintained in the organic medium at the bottom of said oxidation reactor, and wherein the external circulation loop is maintained at pressure during steps c), d) and e). ### Claim 24 (depends on 23) The method as claimed in claim 23 wherein the amount of oxygen added to said volume is controlled to ensure dissolution of said oxygen. ### Claim 25 (depends on 23) The method as claimed in claim 23 wherein the amount of oxygen added to said volume is determined by a process selected from the group consisting of the flow rate of oxygen leaving said oxidation reactor and the concentration of dissolved oxygen in said oxidation reactor. ### Claim 26 (depends on 23) The method as claimed in claim 23 wherein the amount of oxygen added to said volume is controlled to inhibit formation of free bubbles in said oxidation reactor. ### Claim 27 (depends on 23) The method as claimed in claim 23 wherein the depth at which said volume is added to said liquid distributor is sufficient to provide high back pressure to the flow of said volume. ### Claim 28 (depends on 23) The method as claimed in claim 23 wherein feeding of said volume into said oxidation reactor agitates the contents of said oxidation reactor thereby suspending solids and improving heat transfer in said oxidation reactor.