Denitration catalyst regeneration method, denitration catalyst regeneration system, and cleaning agent for denitration catalyst
Provided are: a cleaning agent for a denitration catalyst; and a denitration catalyst regeneration method and a denitration catalyst regeneration system which make it possible to efficiently remove matter adhering to a surface of a catalyst and to greatly restore catalytic performance. The regeneration method includes: a prewashing step (S 12 ) of washing a denitration catalyst with water; a liquid agent cleaning step (S 14 ) of immersing the denitration catalyst washed with water in a liquid agent containing an inorganic acid and a fluorine compound; a step of recovering the denitration catalyst from the liquid agent; and a finish washing step (S 16 ) of washing the denitration catalyst recovered from the liquid agent with a finish cleaning liquid which is water or sulfamic acid-containing water.
1. A method of regenerating a denitration catalyst, comprising:
a prewashing step of washing a denitration catalyst with water;
a liquid agent cleaning step of immersing the denitration catalyst washed with water in a liquid agent containing an inorganic acid and a fluorine compound;
a step of recovering the denitration catalyst from the liquid agent; and
a finish washing step of washing the denitration catalyst recovered from the liquid agent with a finish cleaning liquid which is water or sulfamic acid-containing water,
wherein the inorganic acid includes hydrochloric acid, includes hydrochloric acid and boric acid, or includes sulfamic acid.
2. The method of generating a denitration catalyst according to claim 1 , wherein the liquid agent further contains a surfactant, and wherein the surfactant is a nonionic surfactant or an anionic surfactant.
3. The method of generating a denitration catalyst according to claim 2 , wherein the nonionic surfactant is a surfactant which contains polyoxyethylene polyoxypropylene glycol, a polyoxyethylene derivative, or a polyalkylene glycol derivative as a main component.
4. The method of generating a denitration catalyst according to claim 2 , wherein the anionic surfactant is a surfactant which contains polyoxyalkylene alkyl ether phosphate ester as a main component.
5. The method of generating a denitration catalyst according to claim 1 , wherein the inorganic acid includes hydrochloric acid or includes hydrochloric acid and boric acid.
6. The method of generating a denitration catalyst according to claim 1 , wherein the inorganic acid includes sulfamic acid.
7. The method of generating a denitration catalyst according to claim 1 , including reducing a surface silica concentration after restoration of the denitration catalyst to 6% by mass or less.
8. The method of generating a denitration catalyst according to claim 1 , wherein the prewashing step includes immersing the denitration catalyst in water inside a reservoir, sealing the reservoir, and evacuating air inside the reservoir.
9. The method of generating a denitration catalyst according to claim 1 , wherein the liquid agent cleaning step includes repeatedly using the liquid agent.
10. A system for regenerating a denitration catalyst, comprising:
a prewashing unit which washes a denitration catalyst with water;
a liquid agent cleaning unit which immerses the denitration catalyst washed with water in a liquid agent containing an inorganic acid and a fluorine compound, wherein the inorganic acid includes hydrochloric acid, includes hydrochloric acid and boric acid, or includes sulfamic acid; and
a finish washing unit which finish-washes the denitration catalyst recovered from the liquid agent with a finish cleaning liquid which is water or sulfamic acid-containing water.
11. A cleaning agent which cleans a deactivated denitration catalyst for a coal fired boiler and which includes an aqueous solution containing an inorganic acid and a fluorine compound, wherein the inorganic acid includes hydrochloric acid, includes hydrochloric acid and boric acid, or includes sulfamic acid.
12. The cleaning agent according to claim 11 , further comprising a surfactant, wherein the surfactant is a nonionic surfactant or an anionic surfactant.
13. The cleaning agent according to claim 12 , wherein the nonionic surfactant is a surfactant which contains polyoxyethylene polyoxypropylene glycol, a polyoxyethylene derivative, or a polyalkylene glycol derivative as a main component.
14. The cleaning agent according to claim 12 , wherein the anionic surfactant is a surfactant which contains polyoxyalkylene alkyl ether phosphate ester as a main component.
15. The cleaning agent according to claim 11 , wherein the inorganic acid includes hydrochloric acid or includes hydrochloric acid and boric acid.
16. The cleaning agent according to claim 11 , wherein the inorganic acid includes sulfamic acid.