HONEYCOMB DENITRATION CATALYST FOR FLUE GAS AT 400°C-600°C AND PREPARATION METHOD THEREOF

Abstract

A honeycomb denitration catalyst used for flue gas at 400 C.-600 C. and preparation method thereof. The honeycomb denitration catalyst includes a catalyst coating and a honeycomb ceramic, where a slurry of the catalyst coating is made from components having the following mass percentages: 15%-25% of a zeolite, 5%-10% of a -alumina, 5%-10% of a catalyst auxiliary agent, 5% of a binder, and 50%-70% of deionized water. The honeycomb ceramic is soaked repeatedly into the slurry of the catalyst coating. After the soaking is completed, the obtained product is dried and calcined to obtain the honeycomb denitration catalyst. The honeycomb denitration catalyst contains a catalyst auxiliary agent and has excellent denitration activity at high temperatures, sulphur-resistance and water-tolerance ability, stability and NO.sub.x removing ability.

Claims

1. A honeycomb denitration catalyst used for flue gas at 400 C.-600 C., comprising a catalyst coating and a honeycomb ceramic, wherein the catalyst coating is deposited on surfaces of the honeycomb ceramic, the catalyst coating is made from components having the following mass percentages: a zeolite in an amount of 15%-25%; a -alumina in an amount of 5%-10%; a catalyst auxiliary agent in an amount of 5%-10%; a binder in an amount of 5%; and deionized water in an amount of 50-70%.

2. The honeycomb denitration catalyst of claim 1, wherein the catalyst coating is 2%-15% of the total mass of the honeycomb denitration catalyst.

3. The honeycomb denitration catalyst of claim 1, wherein the zeolite is selected from the group consisting of ZSM-5 type zeolite molecular sieve, A-type zeolite molecular sieve, X-type zeolite molecular sieve, Y-type zeolite molecular sieve, and any combinations thereof

4. The honeycomb denitration catalyst of claim 1, wherein the catalyst auxiliary agent is selected from the group consisting of ammonium molybdate, cerium nitrate, ferrous chloride, ammonium tungstate, chloroplatinic acid, palladium nitrate, and any combinations thereof.

5. The honeycomb denitration catalyst of claim 1, wherein the binder is an inorganic binder or an organic binder.

6. The honeycomb denitration catalyst of claim 5, wherein the inorganic binder is nitrate.

7. The honeycomb denitration catalyst of claim 6, wherein the inorganic binder is cerium nitrate and/or ferric nitrate; and the organic binder is polyvinyl alcohol.

8. A method for preparing a honeycomb denitration catalyst for flue gas at 400 C.-600 C., comprising: (1) mixing 15%-25% by mass of a zeolite, 5%-10% by mass of a -alumina, 5%-10% by mass of a catalyst auxiliary agent, 5% by mass of a binder and 50-70% by mass of deionized water in mass percentages to obtain a mixture and providing the mixture to a stirring mixer to reach an extent of homogeneity; (2) transferring the mixed solution obtained from step (1) into a ball mill and, after a sufficient ball-milling time, obtaining a slurry of a catalyst coating; (3) soaking a honeycomb ceramic repeatedly into the slurry of the catalyst coating and removing excessive slurry of the catalyst coating from surfaces of the honeycomb ceramic by high pressure air blowing and sweeping method; and (4) drying and calcining the coated honeycomb ceramic obtained from step (3) to obtain the honeycomb denitration catalyst for flue gas at 400 C.- 600 C.

9. The method of claim 8, wherein the ball-milling time in step (2) is 24 to 72 hours.

10. The method of claim 8, wherein the soaking time in step (3)is 5 to 20 minutes.

11. The method of claim 8, wherein the drying and calcining in step (4) further comprise: drying at 120 C. for 12 hours, and then calcining at 500 C. to 550 C. for 5 hours.

Description

DETAILED DESCRIPTION

[0027] Further description of the present invention has been made in connection with the following examples.

Example 1

[0028] (1) Providing 15 g of a ZSM-5 type zeolite molecular sieve, 5 g of a -alumina, 5 g of a catalyst auxiliary agent (including ammonium molybdate, cerium nitrate, ferrous chloride, ammonium tungstate and chloroplatinic acid in such mole ratio as Mo:Ce:Fe:W:Pt=60:200:80:120:1), 5 g of a binder (ferric nitrate) and 70 g of deionized water in line with such mass percentage as 15% of a zeolite, 5% of a -alumina, 5% of a catalyst auxiliary agent, 5% of a binder and 70% of deionized water to obtain a mixture and providing the mixture a stir in a mixer to make it reach the extent of homogeneity.

[0029] (2) Transferring the mixed solution obtained from step (1) to a ball mill and obtaining a slurry of a catalyst coating after sufficient ball-milling, the ball-milling time is 24 hours.

[0030] (3) Soaking a honeycomb ceramic repeatedly into the slurry of the catalyst coating and the soaking time is 5 minutes. After that, removing excessive slurry of the catalyst coating from surfaces of the honeycomb ceramic by high pressure air blowing and sweeping method.

[0031] (4) Drying the coated honeycomb ceramic at 120 C. for 12 hours and then calcining it at 500 C. for 5 hours to obtain the honeycomb denitration catalyst; wherein, the catalyst coating accounts for 8% of the total mass of the honeycomb denitration catalyst.

[0032] It is demonstrated by the mock denitration test that when the volume concentration of NO is 1000 ppm, NH.sub.3/NO=1, oxygen concentration is 5%, air flow rate is 10000 h.sup.1, denitration activity of the honeycomb denitration catalyst reach 90% at 400 C.

Example 2

[0033] (1) Providing 25 g of a A-type zeolite molecular sieve, 10 g of a -alumina, 10 g of a catalyst auxiliary agent (including ammonium molybdate, cerium nitrate, ferrous chloride, ammonium tungstate, chloroplatinic acid and palladium nitrate in such mole ratio as Mo:Ce:Fe:W:Pt:Pd=20:160:120:140:1:1), 5 g of a binder (cerium nitrate) and 50 g of deionized water in line with such mass percentage as 25% of a zeolite, 10% of a -alumina, 10% of a catalyst auxiliary agent, 5% of a binder and 50% of deionized water to obtain a mixture and providing the mixture a stir in a mixer to the extent of homogeneity.

[0034] (2) Transferring the mixed solution obtained from step (1) to a ball mill and obtaining a slurry of a catalyst coating after sufficient ball-milling, the ball-milling time is 36 hours.

[0035] (3) Soaking a honeycomb ceramic repeatedly into the slurry of the catalyst coating and the soaking time is 10 minutes. After that, removing excessive slurry of the catalyst coating from surfaces of the honeycomb ceramic by high pressure air blowing and sweeping method.

[0036] (4) Drying the coated honeycomb ceramic at 120 C. for 12 hours and then calcining it at 550 C. for 5 hours to obtain the honeycomb denitration catalyst; wherein, the catalyst coating accounts for 12% of the total mass of the honeycomb denitration catalyst.

[0037] It is demonstrated by the mock denitration test that when the volume concentration of NO is 1000 ppm, NH.sub.3/NO=1:1.1, oxygen concentration is 5%, air flow rate is 10000 h.sup.1, denitration activity of the honeycomb denitration catalyst reach 90% at 450 C.

[0038] Example 3

[0039] (1) Providing 20 g of a X-type zeolite molecular sieve, 7.50 g of a -alumina, 7.5 g of a catalyst auxiliary agent (including ammonium molybdate, cerium nitrate, ferrous chloride, ammonium tungstate, chloroplatinic acid and palladium nitrate in such mole ratio as Mo:Ce:Fe:W:Pt:Pd=60:200:160:160:1:1), 5 g of a binder (including cerium nitrate and ferric nitrate in such a mole ratio as Ce:Fe=5:1) and 60 g of deionized water in line with such mass percentage as 20% of a zeolite, 7.5% of a -alumina, 7.5% of a catalyst auxiliary agent, 5% of a binder and 60% of deionized water to obtain a mixture and providing the mixture a stir in a mixer to the extent of homogeneity.

[0040] (2) Transferring the mixed solution obtained from step (1) to a ball mill and obtaining a slurry of a catalyst coating after sufficient ball-milling, the ball-milling time is 48 hours.

[0041] (3) Soaking a honeycomb ceramic repeatedly into the slurry of the catalyst coating and the soaking time is 15 minutes. After that, removing excessive slurry of the catalyst coating from surfaces of the honeycomb ceramic by high pressure air blowing and sweeping method.

[0042] (4) Drying the coated honeycomb ceramic at 120 C. for 12 hours and then calcining it at 600 C. for 5 hours to obtain the honeycomb denitration catalyst; wherein, the catalyst coating accounts for 14% of the total mass of the honeycomb denitration catalyst.

[0043] It is demonstrated by the mock denitration test that when the volume concentration of NO is 1000ppm, NH.sub.3/NO=1:1.2, oxygen concentration is 5%, air flow rate is 10000 h.sup.1, denitration activity of the honeycomb denitration catalyst reach 90% at 500 C.

[0044] Example 4

[0045] (1) Providing 25 g of a Y-type zeolite molecular sieve, 10 g of a -alumina, 5 g of a catalyst auxiliary agent (including ammonium molybdate, cerium nitrate, ferrous chloride, ammonium tungstate and palladium nitrate in such mole ratio as Mo:Ce:Fe:W:Pd=60:160:120:160:1), 5 g of a binder (including cerium nitrate and ferric nitrate in such a mole ratio as Ce:Fe=1:1) and 55 g of deionized water in line with such mass percentage as 25% of a zeolite, 10% of a -alumina, 5% of a catalyst auxiliary agent, 5% of a binder and 55% of deionized water to obtain a mixture and providing the mixture a stir in a mixer to an extent of homogeneity.

[0046] (2) Transferring the mixed solution obtained from step (1) to a ball mill and obtaining a slurry of a catalyst coating after sufficient ball-milling, the ball-milling time is 72 hours.

[0047] (3) Soaking a honeycomb ceramic repeatedly into the slurry of the catalyst coating and the soaking time is 20 minutes. After that, removing excessive slurry of the catalyst coating from surfaces of the honeycomb ceramic by high pressure air blowing and sweeping method.

[0048] (4) Drying the coated honeycomb ceramic at 120 C. for 12 hours and then calcining it at 500 C. for 5 hours to obtain the honeycomb denitration catalyst; wherein, the catalyst coating accounts for 15% of the total mass of the honeycomb denitration catalyst.

[0049] It is demonstrated by the mock denitration test that when the volume concentration of NO is 1000ppm, NH.sub.3/NO=1 oxygen concentration is 5%, air flow rate is 10000 h.sup.1, denitration activity of the honeycomb denitration catalyst reach 90% at 600 C.

[0050] The above descriptions of examples are conducive for ordinary technicians of the present technical field to understand and exploit the invention. Persons skilled in the art of the present field can easily make various amendments to the above examples and apply the general principle illustrated in here into other examples without the effort of inventive work.

[0051] Therefore, the present invention is not confined or limited to the examples described herein. Any improvements and modifications conducted by persons skilled in the art of the present field according to the present invention and without going beyond the scope of the present invention shall be included in the extent of protection of the present invention.