# US 8,785,341 B2 · Method of regenerating exhaust gas treatment catalyst and exhaust gas treatment catalyst obtained by the method > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,785,341 B2 - Document ID: US8785341B2 - Status: Granted - Kind: B2 - Application number: 12/743,514 - Filed: 2008-10-27 - Published: 2010-11-18 - Granted: 2014-07-22 - Earliest claimed: 2008-02-29 - Assignees: Mitsubishi Heavy Industries, Ltd. - Applicants: Yoshiaki Obayashi; Masashi Kiyosawa - Inventors: Yoshiaki Obayashi; Masashi Kiyosawa - Web page: https://patentgrep.com/patent/US8785341B2 ## CPC - B01D 53/8625: {Nitrogen oxides} - B01D 53/96: Regeneration, reactivation or recycling of reactants - B01J 23/002: {Mixed oxides other than spinels, e.g. perovskite} - B01J 23/92: of catalysts comprising metals, oxides or hydroxides provided for in groups B01J23/02 - B01J23/36 - B01J 37/0009: {Use of binding agents; Moulding; Pressing; Powdering; Granulating; Addition of materials ameliorating the mechanical properties of the product catalyst} - B01J 37/0036: {Grinding} - B01J 38/00: Regeneration or reactivation of catalysts, in general - B01D 2255/20707: Titanium - B01D 2255/20723: Vanadium - B01D 2255/20776: Tungsten - B01D 2257/302: Sulfur oxides - B01J 2523/00: Constitutive chemical elements of heterogeneous catalysts - B01J 2523/47: Titanium - B01J 2523/55: Vanadium - B01J 2523/69: Tungsten - 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) - B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS ## Abstract Provided is a method of regenerating an exhaust gas treatment catalyst 11 having ash adhered to a surface thereof. The method includes a crushing step S1 in which the exhaust gas treatment catalyst 11 is crushed such that 70 to 95 wt % of the whole exhaust gas treatment catalyst 11 becomes coarse pieces 12 having a size exceeding a threshold size S (any value in a range of 0.105 to 1.0 mm); a separating step S2 in which the fragments obtained by crushing the exhaust gas treatment catalyst 11 are separated into the coarse pieces 12 having a size exceeding threshold size S and fine particles 13 having a size not larger than the threshold size S; a pulverizing step S3 in which the coarse pieces 12 thus separated are pulverized to a fine powder having an average particle diameter of not larger than 0.1 mm; a kneading step S4 and a molding step S5 in which the fine powder is kneaded with other raw materials and molded into an exhaust gas treatment catalyst; and a drying step S6 and a calcining step S7 in which the molded precursor is dried and calcined to thus obtain a regenerated exhaust gas treatment catalyst 14. ## Claims ### Claim 1 A method of regenerating an exhaust gas treatment catalyst having ash adhered to a surface thereof, the method characterized by comprising: a crushing step of crushing the exhaust gas treatment catalyst that has been used and has ash adhered to the surface thereof; a separating step of separating the crushed exhaust gas treatment catalyst into coarse pieces having a size exceeding a threshold size S and fine particles having a size not larger than the threshold size S; a pulverizing step of pulverizing the separated coarse pieces into a fine powder; a molding step of molding the pulverized fine powder as a raw material into an exhaust gas treatment catalyst without using the separated fine particles as the raw material; and a calcining step of calcining a molded precursor of the exhaust gas treatment catalyst, wherein the threshold size S has a value not smaller than 0.105 mm. ### Claim 2 (depends on 1) The method according to claim 1, wherein the crushing step is a step in which the exhaust gas treatment catalyst that has been used is crushed such that 70 to 95 wt % of the whole exhaust gas treatment catalyst that has been used becomes the coarse pieces having a size exceeding the threshold size S. ### Claim 3 (depends on 2) The method according to claim 2, wherein the threshold size S has a value not larger than 1.0 mm. ### Claim 4 (depends on 1) The method of according to claim 1, wherein the pulverizing step is a step in which the coarse pieces is pulverized such that the fine powder has an average particle diameter not larger than 0.1 mm. ### Claim 5 (depends on 1) The method according to claim 1, further comprising a treating step of treating exhaust gas from burned coal using the exhaust gas treatment catalyst after the calcining step. ### Claim 6 (depends on 5) The method according to claim 5, wherein the treating step is a step of treating nitrogen oxide in the exhaust gas. ### Claim 7 (depends on 1) The method according to claim 1, wherein a percentage of Fe2O3 in the coarse pieces separated in the separating step is 0.25 wt % or less. ### Claim 8 (depends on 1) The method according to claim 1, wherein the exhaust gas treatment catalyst is made of at least one metal oxide from titanium oxide (TiO2), tungsten oxide (WO3), and vanadium oxide (V2O5). ### Claim 9 (depends on 1) The method of regenerating an exhaust gas treatment catalyst according to claim 1, wherein the crushing step is a step in which the exhaust gas treatment catalyst that has been used and has the ash adhered to the surface thereof is crushed without being washed.