Boehmite is the main raw material to produce aluminum oxide. γ-Al₂O₃ obtained by the calcination of boehmite as the carrier, and load nickel oxide and tungsten trioxide, add a additive-fluorine, thus to produce tungsten trioxide hydrodesulfurization catalyst with high activity. The different purities of boehmite have a certain degree of influence on the activity of the desulfurization catalyst.

 

Low-purity boehmite prepares WO₃ hydrodesulfurization catalyst

1. Take aluminum hydroxide powder generated by aluminum sulfate- sodium aluminate method from boehmite with a purity of 35% by weight, add the extrusion aid and water, extruded strip of 1.2 mm in diameter, dry in an oven at 120 ℃for 4 hours and then roasted at 550 ℃ in a tube furnace under the air for 4 hours to obtain γ-Al₂O₃ (A);

2. Dissolve ammonium fluoride in deionized water, add the carrier which is cooled down to room temperature for impregnation for 4 hours at room temperature;

3. Separate and dry the wet fluorinated alumina bar in an oven at 120 ℃ for 4 hours, then heated at 500 ℃ in a tube furnace with dry air for 4 hours to obtain fluorinated alumina strip, removed and cooled down to room temperature;

4. Add fluorided alumina to the deionized water containing with ammonium metatungstate and nickel nitrate, and separate after dip at room temperature for 4 hours to obtain wet catalyst;

5. Dry the wet catalyst in an oven at 120 ℃ for 4 hours, and calcine under the air in a tube furnace at 500 ℃ for 4 hours to obtain the catalyst A.

 

High-purity boehmite prepares WO₃ hydrodesulfurization catalyst

1. Take aluminum hydroxide powder (obtained from the hydrolysis of aluminum alkoxide) with the boehmite purity of 70% by weight, add extrusion aid and water, then squeeze to a strip with a diameter of 1.2 mm, dry in an oven at 120 ℃ for 4 hours, then calcine at 550 ℃ for 4 hours in a tube furnace accompanying with the air to give γ-Al₂O₃ (B);

2. γ-Al₂O₃ (B) for the preparation of the carrier catalyst B, the same preparing method of the low purity boehmite.

 

Analysis showed that the aluminum oxide generated from high-purity of boehmite has the larger amount of acid, while the boehmite prepared by calcination has a larger amount of strong acid; tungsten desulfurization catalyst B prepared by aluminum alkoxide hydrolysis of a high-purity oxide boehmite has a higher activity.