Method for removing liquid-phase benzene retained in catalyst of liquid-phase ethylbenzene alkylation and transalkylation reactor through superheated benzene steam purging

Abstract

The invention discloses a method for removing liquid-phase benzene retained in a catalyst of a liquid-phase ethylbenzene alkylation and transalkylation reactor through superheated benzene steam purging. The superheated benzene steam is used as a purging medium and can replace most of the existing steam purging methods for ethylbenzene production devices by a liquid phase method so that the servicelife of the catalyst of an ethylbenzene unit is prolonged, and the selectivity and the conversion rate of a regenerant are prevented from deteriorating; compared with a method for removing the liquid-phase benzene in the catalyst through hot nitrogen purging, the method is beneficial to reducing the equipment investment of a circulating nitrogen system and reducing the one-way purging consumptionof nitrogen, and the economic benefit is more outstanding.

Description

technical field [0001] The invention belongs to the field of petrochemical industry, and relates to a method for purging and removing liquid-phase ethylbenzene alkylation and transalkylation reactor catalysts of liquid-phase benzene by superheated benzene vapor. Background technique [0002] Ethylbenzene is an important chemical raw material. It is mainly used as a raw material for the production of styrene monomer. Styrene is a raw material for polystyrene and its copolymers, and is widely used in the market. At present, the production of ethylbenzene mainly adopts the production method of alkylation of benzene and ethylene. Benzene and ethylene feed pass through an adsorption bed containing an adsorbent to remove basic nitrogen-containing impurities, and then generate ethylbenzene under the action of Y-type molecular sieve, β-type molecular sieve or MCM-type molecular sieve alkylation catalyst, and the generated ethylbenzene will also be combined with Ethylene is further ...

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Problems solved by technology

[0017] The above three methods have their own deficiencies. The first method has low construction cost, and only needs to add a nitrogen heater to achieve the above purpose, but it will lead to the problem of steam condensate damage to the aluminum skeleton of the catalyst and the problem of alkali poisoning of the acidic catalyst; The investment and land occupation of the circulating hot nitrogen system in the second method is large; the third method needs to waste a lot of nitrogen and increase the VOC emission of benzene, a highly toxic substance.

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