# US 7,608,232 B2 · Treatment method and treatment apparatus for gas containing nitrous oxide > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,608,232 B2 - Document ID: US7608232B2 - Status: Granted - Kind: B2 - Application number: 11/791,343 - Filed: 2005-11-15 - Published: 2007-12-20 - Granted: 2009-10-27 - Earliest claimed: 2004-11-30 - Assignees: Showa Denko K.K. - Inventors: Masatoshi Hotta - Web page: https://patentgrep.com/patent/US7608232B2 ## CPC - B01D 53/8631: {Processes characterised by a specific device} - A61M 16/009: {Removing used or expired gases or anaesthetic vapours (filtering, sterilising or disinfecting the exhaust air in drainage systems A61M1/784; bacterial filters in the expiratory path A61M16/1065)} - B01J 8/025: {in a cylindrical shaped bed} - B01J 8/0278: {Feeding reactive fluids (for solid material B01J8/0015)} - B01J 8/0285: {Heating or cooling the reactor (for tubular reactors in furnaces B01J8/062)} - B01J 23/56: Platinum group metals - B01J 23/8906: {Iron and noble metals} - A61M 2202/0283: Nitrous oxide (N2O) - B01D 2257/402: Dinitrogen oxide - B01J 2208/00185: Fingers - B01J 2208/00849: outside the bed, e.g. baffles - Y02C 20/10: of nitrous oxide (N2O) - B01D: SEPARATION (separating solids from solids by wet methods B03B, B03D; by pneumatic jigs or tables B03B; by other dry methods B07; magnetic or electrostatic separation of solid materials from solid materials or fluids, separation by high-voltage electric fields B03C; centrifuges, vortex apparatus B04; presses per se for squeezing-out liquid from liquid-containing material B30B9/02; treatment of water C02F, e.g. softening by ion-exchange C02F1/42; {arrangements of air intake cleaners in gas turbine plants F02C7/05} ; arrangements or mounting of filters in air-conditioning, air-humidification or ventilation F24F13/28) - A61M: DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY (introducing media into or onto the bodies of animals A61D7/00; means for inserting tampons A61F13/26; devices for administering food or medicines orally A61J; containers for collecting, storing or administering blood or medical fluids A61J1/05); DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY (surgery A61B; chemical aspects of surgical articles A61L); DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR {(Electrotherapy, e.g. producing anaesthesia by the use of alternating or intermittent currents A61N1/36021)} - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG] ## Abstract Nitrous oxide-containing gas is subjected to heat exchange with decomposed gas from a nitrous oxide decomposition catalyst-filled reactor and then contacted with a heater comprising integrally formed heating unit and baffles, wherein gaps are formed between the baffle-integrated heater and the unit body in order to alleviate the pressure difference in the gas flow channel, and subsequently introduced into a nitrous oxide catalyst-filled catalyst layer for decomposition of the nitrous oxide into nitrogen and oxygen. The nitrous oxide-containing gas is neutralized by continuous treatment. ## Claims ### Claim 1 A treatment method for nitrous oxide-containing gas, wherein in a method of contacting nitrous oxide-containing gas with a catalyst for decomposition treatment of the nitrous oxide in said gas, said gas is introduced into a flow channel comprising a heating unit and multiple gaps, said gas is split into a gas stream flowing along the flow channel and a gas stream flowing through the gaps formed in the flow channel, the gas stream flowing along the flow channel is directed to merge with the split gas stream, and said gas is contacted with the heating unit to raise the temperature to a prescribed temperature before contacting with a catalyst for decomposition of the nitrous oxide. ### Claim 2 (depends on 1) A gas treatment method according to claim 1, wherein the gaps formed in said flow channel are either formed between the baffles integrally formed with the heating unit, or between the baffles integrally formed with the heating unit and the baffles formed on the walls of the decomposition reaction unit. ### Claim 3 (depends on 1) A gas treatment method according to claim 1, wherein the concentration of the nitrous oxide contained in said gas is between 10 ppm and 30%. ### Claim 4 (depends on 1) A gas treatment method according to claim 1, wherein the nitrous oxide decomposition temperature is 200-600° C. ### Claim 5 (depends on 1) A gas treatment method according to claim 1, wherein the content of NOx produced during decomposition of the nitrous oxide is no greater than 5 ppm. ### Claim 6 (depends on 1) A gas treatment method according to claim 1, wherein the concentration of nitrous oxide contained in the nitrous oxide-decomposed gas is detected and the nitrous oxide decomposition temperature is controlled based on the detected nitrous oxide concentration. ### Claim 7 A treatment apparatus for nitrous oxide-containing gas, wherein a unit in which nitrous oxide-containing gas is contacted with a catalyst for decomposition treatment of the nitrous oxide in said gas comprises a heat exchanger, a heating unit integrally formed with baffles, a decomposition reactor filled with a nitrous oxide decomposition catalyst and a detector which detects the concentration of nitrous oxide in the gas exiting the decomposition reactor, wherein a gas flow channel is formed by the baffles integrally formed with said heating unit, the baffles formed on the walls of the decomposition reaction unit and the walls of the decomposition unit, while gaps are formed in said flow channel either between said baffles, or between said baffles and the baffles formed on the wall of the decomposition reaction unit. ### Claim 8 (depends on 7) A gas treatment apparatus according to claim 7, wherein the nitrous oxide-containing gas is introduced into a heat exchanger and then allowed to flow through said gas flow channel and a decomposition reactor, and discharged after being again circulated through the heat exchanger. ### Claim 9 (depends on 7) A gas treatment apparatus according to claim 7, which is provided with a temperature controlling unit which detects the concentration of nitrous oxide in the gas with said detector before and after it is introduced into the heat exchanger, and controls the temperature of said decomposition reactor based on the detected nitrous oxide concentration. ### Claim 10 (depends on 7) A gas treatment apparatus according to claim 7, wherein the heating unit integrally formed with the baffles is detachable from said decomposition treatment apparatus.