Low temperature NH3-SCR denitration catalyst for flue gas with low water vapor content, and preparation method thereof

[0044] Example 1

[0045] Weigh 7.44g of niobium oxalate and dissolve in 20ml of deionized water at 50°C. After the niobium oxalate is completely dissolved, add 21.05g of cerium nitrate and 7.92g of manganese acetate to the niobium oxalate solution to form a mixed solution, and add 12.91g of TiO 2 Prepare the mixture, keep the mixture at 50°C and stir for 1 hour to make the mixture fully homogeneous, and let stand for 1 hour. Dry at 120°C for 12 hours and bake at 550°C for 6h. The roasted product is cooled, pulverized, sieved, and the powder smaller than 80 mesh is taken for later use. Weigh 7.00g of powder less than 80 mesh and mix with 3.00g of pseudo-boehmite powder evenly, add 2.0ml of 10wt% nitric acid solution to the mixed powder and mix evenly to form a dough, put it into a syringe and extrude into strips, Drying at 550°C for 6 hours. Cool after roasting, crush and sieve to take the 20-40 mesh part as the catalyst.

[0046] The detection method of the denitrification rate of the prepared catalyst is as follows: first, measure the NO concentration in the simulated flue gas before passing through the reactor with a NOx nitrogen oxide analyzer, then put the catalyst in a tubular fixed-bed reactor, and heat the reactor through an electric furnace. Heating to the required temperature, passing simulated flue gas and reducing agent NH 3 , use NOx nitrogen oxide analyzer to measure the NO concentration in the flue gas at the outlet of the reactor, the denitrification rate of the catalyst is calculated as:

[0047]

[0048] In the above formula: Co is the concentration of NO before entering the reactor; C is the concentration of NO at the outlet of the reactor.

[0049] Detection of catalyst for SO 2 When it is resistant to water vapor, 1000ppmSO is introduced into the simulated flue gas 2 and 12% water vapor.

[0050] According to the results of the activity test, the catalyst can be used at a temperature of 160°C and a space velocity of 20000h -1 , NO, NH 3 and SO 2 Concentration 1000ppm, O 2 With a content of 1%, the denitrification rate can reach 82.8% in the presence of 12% water vapor.

[0051] Example 2

[0052] Weigh 1.86g of niobium oxalate and dissolve in 20ml of deionized water at 50°C. After the niobium oxalate is completely dissolved, add 21.05g of cerium nitrate and 7.92g of manganese acetate into the niobium oxalate solution to form a mixed solution, and add 12.91g of TiO 2 Prepare the mixture, keep the mixture at 50°C and stir for 1 hour to make the mixture fully homogeneous, and let stand for 1 hour. Dry at 120°C for 12 hours and bake at 550°C for 6h. The roasted product is cooled, pulverized, sieved, and the powder smaller than 80 mesh is taken for later use. Weigh 7.00g of powder less than 80 mesh and mix with 3.00g of pseudo-boehmite powder evenly, add 2.0ml of 10wt% nitric acid solution to the mixed powder and mix evenly to form a dough, put it into a syringe and extrude into strips, Drying at 550°C for 6 hours. Cool after roasting, crush and sieve to take the 20-40 mesh part as the catalyst.

[0053] The detection method of the denitration rate of the prepared catalyst is the same as that in Example 1.

[0054] According to the results of the activity test, the catalyst can be used at a temperature of 160°C and a space velocity of 20000h -1 , NO, NH 3 and SO 2 Concentration 1000ppm, O 2 With a content of 1%, the denitrification rate can reach 83.6% in the presence of 12% water vapor.

[0055] Example 3

[0056] Weigh 21.05g of cerium nitrate and 7.92g of manganese acetate dissolved in 20ml of deionized water at 50°C to form a mixed solution, and add 12.91g of TiO to the mixed solution 2 Prepare the mixture, keep the mixture at 50°C and stir for 1 hour to make the mixture fully homogeneous, and let stand for 1 hour. Dry at 120°C for 12 hours and bake at 550°C for 6h. The roasted product is cooled, pulverized, sieved, and the powder smaller than 80 mesh is taken for later use. Weigh 7.00g of powder less than 80 mesh and mix with 3.00g of pseudo-boehmite powder evenly, add 2.0ml of 10wt% nitric acid solution to the mixed powder and mix evenly to form a dough, put it into a syringe and extrude into strips. Drying at 550°C for 6 hours. Cool after roasting, crush and sieve to take the 20-40 mesh part as the catalyst.

[0057] The detection method of the denitration rate of the prepared catalyst is the same as that in Example 1.

[0058] According to the results of the activity test, the catalyst can be used at a temperature of 160°C and a space velocity of 20000h -1 , NO, NH 3 and SO 2 Concentration 1000ppm, O 2 With a content of 1%, the denitrification rate can reach 68.7% in the presence of 12% water vapor.

[0059] attached Image 6 It can be clearly seen that after the addition of Nb, the catalyst is resistant to high concentrations of water vapor and SO 2 The resistance has been significantly improved.