# US 11,439,997 B2 · Neutral complex cleaning solution and regeneration method for denitration catalyst with calcium poisoning > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,439,997 B2 - Document ID: US11439997B2 - Status: Granted - Kind: B2 - Application number: 16/332,967 - Filed: 2017-09-28 - Published: 2019-09-12 - Granted: 2022-09-13 - Earliest claimed: 2017-05-24 - Applicants: Tsinghua University - Inventors: Junhua Li; Xiansheng Li; Xiang Li; Yue Peng; Jianjun Chen - Web page: https://patentgrep.com/patent/US11439997B2 ## CPC - B01J 38/52: oxygen-containing - B01D 53/8628: {Processes characterised by a specific catalyst} - B01D 53/96: Regeneration, reactivation or recycling of reactants - B01J 23/30: Tungsten - B01J 23/92: of catalysts comprising metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 - B01J 37/343: {of ultrasonic wave energy} - B01J 38/12: Treating with free oxygen-containing gas - B01J 38/48: Liquid treating or treating in liquid phase, e.g. dissolved or suspended - B01D 2255/2045: Calcium - B01D 2255/20707: Titanium - B01D 2255/20723: Vanadium - B01D 2255/20776: Tungsten - B01D 2257/404: Nitrogen oxides other than dinitrogen oxide - B01J 2523/00: Constitutive chemical elements of heterogeneous catalysts - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS - 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) ## Abstract The invention belongs to the field of nitrogen oxide control in environmental protection science and technology, and particularly relates to the field of regeneration and utilization of SCR denitration catalyst with calcium poisoning, that is a neutral complex cleaning liquid and a regeneration method for denitration catalyst with calcium poisoning. The present invention uses a neutral polyether surfactant as a regeneration and calcium removal reagent to achieve a poisoned catalyst regeneration method with high calcium removal rate, low loss rate of active components and excellent recovery of denitrification activity; wherein the content of the polyether surfactant is in the range of 0.1-1 wt %; by the regeneration method of the present invention, the loading of active components which is required in the conventional regeneration process can be omitted, while the corrosion of equipment and catalyst can be reduced, thus capable of regenerating the denitration catalyst with high efficiency. ## Claims ### Claim 1 A regeneration method of denitration catalyst with calcium poisoning, comprising the steps of: (a) providing a neutral complex cleaning solution comprising active ingredients of polyether surfactant, wherein said polyether surfactant is NP-10 (POLYETHYLENE GLYCOL TRIMETHYLNONYL ETHER); (b) removing impurities remaining on a surface and inside pores of a poisoned denitration catalyst and drying under room temperature; (c) after drying, placing the poisoned denitration catalyst in the neutral complex cleaning solution for carrying out an ultrasonic cleaning process for 30 min-2 h and then allow it to stand for 1-24 h; and (d) after standing, taking out the denitration catalyst and processing washing, air drying, heat drying, and calcination to obtain a regenerated denitration catalyst. ### Claim 2 (depends on 1) The regeneration method of denitration catalyst with calcium poisoning according to claim 1, in the step (c), the solid to liquid ratio is 1:10-1:100, the cleaning time is 0.5-2 h, the cleaning temperature is 20° C. ### Claim 3 (depends on 1) The regeneration method of denitration catalyst with calcium poisoning according to claim 1, wherein in step (c), further comprising the substeps of: washing with deionized water, air drying until a water content is below 15-30%, heated drying under 80-160° C. for 12-72 hours, and then increasing temperature to 500-700° C. at a rate of 1-10° C./min and carrying out calcination under air condition for 4-24 hours to obtain the regenerated denitration catalyst is carried out after taking out the denitration catalyst. ### Claim 4 (depends on 1) The regeneration method of denitration catalyst with calcium poisoning according to claim 1, wherein said neutral complex cleaning solution consists of 0.1-1 wt % of polyether surfactant and deionized water. ### Claim 5 A regeneration method of denitration catalyst with calcium poisoning, comprising the steps of: (a) providing a neutral complex cleaning solution comprising active ingredients of NP-10 (POLYETHYLENE GLYCOL TRIMETHYLNONYL ETHER) serving as a polyether surfactant; and (b) cleaning a poisoned denitration catalyst with calcium poisoning by using the neutral complex cleaning solution, thereby a denitration efficiency of about 90% and a calcium removal rate of about 88% is achieved while a loss of active ingredients of the poisoned denitration catalyst is minimized. ### Claim 6 (depends on 5) The regeneration method of denitration catalyst with calcium poisoning according to claim 5, wherein said neutral complex cleaning solution consists of 0.1-1 wt % of polyether surfactant and deionized water. ### Claim 7 (depends on 6) The regeneration method of denitration catalyst with calcium poisoning according to claim 6, further comprising the steps of: before step (b), removing impurities remaining on a surface and inside pores of the poisoned denitration catalyst and drying under room temperature until the poisoned catalyst is dried; in step (b), the cleaning process is an ultrasonic cleaning process which is carried out for 30 min-2 h, and after step (b), allowing standing time of 1-24 hours.