# US 5,701,763 A · Cryogenic hybrid system for producing low purity oxygen and high purity nitrogen > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,701,763 A - Document ID: US5701763A - Status: Granted - Kind: A - Application number: 08/778,075 - Filed: 1997-01-07 - Granted: 1997-12-30 - Earliest claimed: 1997-01-07 - Assignees: Praxair Technology, Inc. - Inventors: Henry Edward Howard; Dante Patrick Bonaquist - Web page: https://patentgrep.com/patent/US5701763A ## CPC - B01D 53/04: with stationary adsorbents {(B01D53/025 takes precedence)} - F25J 3/04296: {Claude expansion, i.e. expanded into the main or high pressure column} - F25J 3/04636: {using a hybrid air separation unit, e.g. combined process by cryogenic separation and non-cryogenic separation techniques (F25J3/04733 and F25J3/04757 take precedence)} - B01D 2256/10: Nitrogen - B01D 2257/102: Nitrogen - B01D 2257/104: Oxygen - B01D 2257/504: Carbon dioxide - B01D 2257/80: Water - B01D 2259/402: using two beds - B01D 2259/404: using four beds - B01D 2259/416: involving cryogenic temperature treatment - F25J 2200/02: in a single pressure main column system - F25J 2200/72: Refluxing the column with at least a part of the totally condensed overhead gas - F25J 2205/60: using adsorption on solid adsorbents, e.g. by temperature-swing adsorption [TSA] at the hot or cold end - F25J 2205/66: Regenerating the adsorption vessel, e.g. kind of reactivation gas - F25J 2210/04: Mixing or blending of fluids with the feed stream - F25J 2215/44: Ultra high purity nitrogen, i.e. generally less than 1 ppb impurities - F25J 2215/50: Oxygen or special cases, e.g. isotope-mixtures or low purity O2 - F25J 2245/50: the recycled stream being oxygen - Y02C 20/40: of CO2 - Y10S 62/908: Filter or absorber - 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) - F25J: LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS {OR LIQUEFIED GASEOUS} MIXTURES BY PRESSURE AND COLD TREATMENT {OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE (cryogenic pumps F04B37/08; gas storage vessels, gas holders F17; filing vessels with, or discharging from vessels, compressed, liquefied or solidified gases F17C; refrigeration machines, plants, or systems F25B)} - Y02C: CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG] - Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS ## Abstract A hybrid system for producing both low purity oxygen and high purity nitrogen at high product recovery rates wherein desorption effluent from an adsorbent system feeds a cryogenic rectification column and, preferably, bottom fluid from the column provides additional feed for the adsorbent system. ## Claims ### Claim 1 A method for producing low purity oxygen and high purity nitrogen comprising: (A) passing feed air into an adsorbent system comprising at least one adsorbent bed and adsorbing nitrogen from the feed air within the adsorbent system to produce oxygen-enriched vapor and nitrogen-enriched vapor; (B) recovering oxygen-enriched vapor as product low purity oxygen; (C) passing nitrogen-enriched vapor into a column and separating the nitrogen-enriched vapor by cryogenic rectification within the column into nitrogen top fluid and oxygen-containing bottom fluid; and (D) recovering nitrogen top fluid as product high purity nitrogen. ### Claim 2 (depends on 1) The method of claim 1 further comprising passing oxygen-containing bottom fluid into the adsorbent system for further production of oxygen-enriched vapor and nitrogen-enriched vapor. ### Claim 3 (depends on 1) The method of claim 1 wherein the nitrogen-enriched vapor is compressed prior to being passed into the column. ### Claim 4 (depends on 1) The method of claim 1 wherein the nitrogen-enriched vapor is cleaned of high boiling impurities prior to being passed into the column. ### Claim 5 (depends on 1) The method claim 1 wherein the nitrogen-enriched vapor is cooled and at least a portion of the nitrogen-enriched vapor is turboexpanded prior to being passed into the column. ### Claim 6 Apparatus for producing low purity oxygen and high purity nitrogen comprising: (A) an adsorbent system comprising at least one adsorbent bed and having feed input means whereby feed air is passed into the adsorbent system; (B) means for recovering low purity oxygen from the adsorbent system; (C) means for passing nitrogen-enriched vapor from the adsorbent system into a cryogenic rectification column; and (D) means for recovering fluid from the upper portion of the cryogenic rectification column as product high purity nitrogen. ### Claim 7 (depends on 6) The apparatus of claim 6 further comprising means for passing fluid from the lower portion of the column into the feed input means of the adsorbent system. ### Claim 8 (depends on 6) The apparatus of claim 6 wherein the means for passing nitrogen-enriched vapor from the adsorbent system into the cryogenic rectification column comprises a compressor. ### Claim 9 (depends on 6) The apparatus of claim 6 wherein the means for passing nitrogen-enriched vapor from the adsorbent system into the cryogenic rectification column comprises a second adsorbent system for removing high boiling impurities from the nitrogen-enriched vapor. ### Claim 10 (depends on 6) The apparatus of claim 6 wherein the means for passing nitrogen-enriched vapor from the adsorbent system into the cryogenic rectification column comprises a turboexpanded.