Ethyl benzene oxidizing-dehydrogenation catalyst

Abstract

This invention discloses an ethyl benzene oxy-dehydrogenation catalyst, its feature is that it is mainly consisted by active constituent and auxiliary agent, the active constituent said is molecular sieve with vanadium element in bone frame structure, and the auxiliary agent is alkali metal or. The content of the auxiliary agent computed as metal oxide in every gram catalyst is 0.01-3.0mmol.

Description

technical field

[0001] The invention relates to a catalyst for oxidative dehydrogenation of ethylbenzene, and more particularly relates to a catalyst for preparing styrene by oxidative dehydrogenation of ethylbenzene with molecular sieve as an active component and a supporting auxiliary agent under a carbon dioxide atmosphere. Background technique

[0002] Styrene is an important chemical raw material, and 90% of its output is produced by the direct dehydrogenation of ethylbenzene on an iron oxide catalyst. This method requires a large amount of superheated steam, which is condensed into liquid after the reaction, and the latent heat of vaporization of the water vapor is not recycled, so the energy consumption is relatively large, and the method has the disadvantage that the yield of styrene is limited by thermodynamic equilibrium. In this reaction system, if CO 2 Replacing water vapor can increase the equilibrium conversion rate of ethylbenzene and r...

Examples

Embodiment 1

[0019] The synthesis of VAPO-5 molecular sieve: 15g dry rubber powder (Al 2 o 3Content 65.8%, produced by Changling Catalyst Factory), add 60mL of water and beat for 60 minutes, then slowly add 14g orthophosphoric acid solution (phosphoric acid content 85%, produced by Beijing Reagent Factory) dropwise therein. After stirring for 10 minutes, add 2.3 grams of vanadyl sulfate pentahydrate (V content 22%, dissolved in 2 g of water), continue stirring at room temperature for 60 minutes, then add 16 mL template agent triethylamine (content 98%, Beijing Reagent factory production). After continuing to stir for 1 hour, place in a crystallization kettle for dynamic crystallization at 175° C. for 72 hours. The obtained product was washed with water and then dried at 80°C. The sample was roasted at a temperature programmed in flowing air (120°C, 1 hour; 3°C / min to 550°C; kept for 4 hours and then slowly cooled to room temperature). The X-ray diffraction (XRD) spectrum of the obtained...

Embodiment 2

[0022] Accurately weigh 0.533g of sodium nitrate, add water to 20ml, and stir until the sodium nitrate is completely dissolved; then accurately weigh 20.000g of VAPO-5 molecular sieve (above 40 mesh) dried at 393K, impregnate the molecular sieve with the configured sodium nitrate solution, Let it stand for 24 hours, dry it in an oven at 383K for 24 hours, roast it at 773K for 3 hours, and put it into a desiccator to obtain a Na / VAPO-5 catalyst, which is designated as catalyst B. The composition of the catalyst is 0.01mmolNa 2 O / g VAPO-5.

Embodiment 3

[0024] Accurately weigh 0.414g of lithium nitrate, add water to 20ml, and stir until the lithium nitrate is completely dissolved; then accurately weigh 20.000g of VAPO-5 molecular sieve (above 40 mesh) dried at 393K, impregnate the molecular sieve with the prepared lithium nitrate solution, Let it stand for 24 hours, dry it in an oven at 383K for 24 hours, roast it at 773K for 3 hours, and put it into a desiccator to obtain a Li / VAPO-5 catalyst, which is designated as catalyst C. The composition of the catalyst is 0.5mmolLi 2 O / g VAPO-5.

technical field

[0001] The invention relates to a catalyst for oxidative dehydrogenation of ethylbenzene, and more particularly relates to a catalyst for preparing styrene by oxidative dehydrogenation of ethylbenzene with molecular sieve as an active component and a supporting auxiliary agent under a carbon dioxide atmosphere. Background technique

[0002] Styrene is an important chemical raw material, and 90% of its output is produced by the direct dehydrogenation of ethylbenzene on an iron oxide catalyst. This method requires a large amount of superheated steam, which is condensed into liquid after the reaction, and the latent heat of vaporization of the water vapor is not recycled, so the energy consumption is relatively large, and the method has the disadvantage that the yield of styrene is limited by thermodynamic equilibrium. In this reaction system, if CO 2 Replacing water vapor can increase the equilibrium conversion rate of ethylbenzene and r...

Examples

Embodiment 1

[0019] The synthesis of VAPO-5 molecular sieve: 15g dry rubber powder (Al 2 o 3Content 65.8%, produced by Changling Catalyst Factory), add 60mL of water and beat for 60 minutes, then slowly add 14g orthophosphoric acid solution (phosphoric acid content 85%, produced by Beijing Reagent Factory) dropwise therein. After stirring for 10 minutes, add 2.3 grams of vanadyl sulfate pentahydrate (V content 22%, dissolved in 2 g of water), continue stirring at room temperature for 60 minutes, then add 16 mL template agent triethylamine (content 98%, Beijing Reagent factory production). After continuing to stir for 1 hour, place in a crystallization kettle for dynamic crystallization at 175° C. for 72 hours. The obtained product was washed with water and then dried at 80°C. The sample was roasted at a temperature programmed in flowing air (120°C, 1 hour; 3°C / min to 550°C; kept for 4 hours and then slowly cooled to room temperature). The X-ray diffraction (XRD) spectrum of the obtained...

Embodiment 2

[0022] Accurately weigh 0.533g of sodium nitrate, add water to 20ml, and stir until the sodium nitrate is completely dissolved; then accurately weigh 20.000g of VAPO-5 molecular sieve (above 40 mesh) dried at 393K, impregnate the molecular sieve with the configured sodium nitrate solution, Let it stand for 24 hours, dry it in an oven at 383K for 24 hours, roast it at 773K for 3 hours, and put it into a desiccator to obtain a Na / VAPO-5 catalyst, which is designated as catalyst B. The composition of the catalyst is 0.01mmolNa 2 O / g VAPO-5.

Embodiment 3

[0024] Accurately weigh 0.414g of lithium nitrate, add water to 20ml, and stir until the lithium nitrate is completely dissolved; then accurately weigh 20.000g of VAPO-5 molecular sieve (above 40 mesh) dried at 393K, impregnate the molecular sieve with the prepared lithium nitrate solution, Let it stand for 24 hours, dry it in an oven at 383K for 24 hours, roast it at 773K for 3 hours, and put it into a desiccator to obtain a Li / VAPO-5 catalyst, which is designated as catalyst C. The composition of the catalyst is 0.5mmolLi 2 O / g VAPO-5.