Catalyst for preparing styrene from ethylbenzene dehydrogenation and preparation method thereof

Abstract

The invention discloses a catalyst used for preparing styrene through ethylbenzene dehydrogenation. The active ingredient of the catalyst is V2O5, and the auxiliary component is cerium-zirconium-aluminum composite oxide; and the general formula of the catalyst is zV2O5-yCexZr1-xO2-Al2O3, wherein x is the mole number of Ce atom, y is the mass percentage of cerium-zirconium solid solution in the cerium-zirconium-aluminum composite oxide, z is the mass percentage of V2O5 in the catalyst, x is 0.3-0.7, y is 0.5%-30% and z is 1%-15%. The catalyst is directly synthesized through a hydrothermal method in one step, the synthetic raw material is cheap, the reaction conditions are easy to control, and the method is simple; and the obtained catalyst is used to prepare styrene through ethylbenzene dehydrogenation, the maximum conversion rate of ethylbenzene is up to about 73% and the selectivity of styrene is up to more than 98%.

Description

technical field [0001] The invention belongs to the technical field of catalysts, and in particular relates to a catalyst for dehydrogenating ethylbenzene to produce styrene and hydrocarbon dehydrogenation and a preparation method thereof. Background technique [0002] At present, about 85% of styrene in industry is realized through direct dehydrogenation of ethylbenzene. But its high energy consumption makes people have to consider developing new energy-saving processes in today's era of energy shortage. According to literature reports, from the perspective of breaking the limitation of thermodynamic equilibrium, solving the self-heating problem and reducing the reaction temperature, the oxidative dehydrogenation of ethylbenzene is currently the most promising alternative method for the production of styrene. The Smart process jointly developed by UOP and Lummus in the United States is to add an appropriate amount of O to the product in the middle of the two radial dehydro...

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Problems solved by technology

But this process also has some disadvantages: such as H 2 Improper control of the mixed concentration of ethylbenzene dehydrogenation products can cause explosions; excessively introduced O 2 It can also lead to catalyst poisoning and reduced selectivity to styrene, etc.

However, the preparation of the cerium-zirconium-aluminum composite oxide carrier by the sol-gel method has the disadvantages of high raw material cost, long synthesis cycle, difficult control of the hydrolysis rate of the raw material alkoxide, and easy hardening of the gel, which affects the performance of the ethylbenzene dehydrogenation reaction. At the same time, The traditional loading method needs to prepare the carrier first and then load the active component, which is time-consuming

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