Method for removing phenylacetylene in presence of styrene

Abstract

The invention relates to a method for removing phenylacetylene in the presence of styrene. According to the requirements of adaptability to water or water content fluctuation of a reaction system and inhibition of carbon deposit in the selective hydrogenation process of the phenylacetylene at present, a hydrogen / phenylacetylene hydrocarbon mixture in a certain molar ratio is introduced into a reactor and contacted with a hydrogenation catalyst to remove the phenylacetylene at the inlet temperature of between 10 and 120 DEG C under the pressure of 0.1 to 4.0MPa, wherein the hydrogenation catalyst comprises a carrier, metal active ingredients and a silane group which is grafted by silylation and accounts for 0.1 to 15 weight percent of the catalyst. Compared with the prior art, the method has the advantages that: the method is high in raw material applicability on the premise of ensuring that the catalyst in the method has high activity and selectivity, and the catalytic performance of the selective hydrogenation catalyst is almost not influenced by trace water; meanwhile, the carbon deposit on the surface of the catalyst can be obviously inhibited, the service life of the catalyst is prolonged, and the catalyst has a long stable operation period.

Description

technical field [0001] The present invention relates to a hydrogenation process, and more particularly, the present invention relates to a process for removing phenylacetylene in the presence of styrene. Background technique [0002] Styrene is an important monomer for the production of polystyrene, ABS and styrene-butadiene rubber. Its production method is based on ethylbenzene dehydrogenation. In recent years, with the expansion of industrial production scale of ethylene, extraction and recovery of styrene from pyrolysis gasoline has become one of the technologies for increasing styrene production that has attracted much attention. [0003] When the ethylbenzene dehydrogenation method is used to prepare styrene, in addition to the formation of styrene, the dehydrogenation of ethylbenzene will also be accompanied by the side reaction of deep dehydrogenation of ethylbenzene to form phenylacetylene, although usually coexisting in the prepared styrene product Ethylbenzene ca...

AI Technical Summary

Problems solved by technology

The hydrogenation gas includes a mixture of nitrogen and hydrogen. The reaction temperature of this technology is relatively high, and the hydrogenation rate of phenylacetylene is low (about 70%) when the volume content of phenylacetylene is less than 1.0%. around 3.0%

[0005] Chinese patent CN1087892A discloses a method and equipment for purifying styrene monomer in a styrene stream by hydrogenation. It dilutes the hydrogen by adding hydrogen to a diluent such as nitrogen, and uses ethylbenzene to dehydrogenate the exhaust gas to provide hydrogen. Styrene impurity is hydrogenated into styrene by the reactor of multistage catalytic bed, but only mentions the selective alkyne removal method of low concentration such as 300ppm phenylacetylene content in this patent catalyst, simultaneously to phenylacetylene hydrogenation rate is low (95% About), and the loss of styrene is about 0.2%

[0006] Chinese patent CN101475438A proposes a method that is: using hydrocarbon fractions containing phenylacetylene as raw material, the reaction temperature is 15-100°C, and the weight space velocity is 0.01-100 hours -1 , the hydrogen / phenylacetylene molar ratio is 1 to 30:1, and the reaction pressure is -0.08 to 50.MPa, the raw material is in contact with the carbon-containing oxide catalyst, and the phenylacetylene in the reactant stream is hydrogenated to styrene, which contains carbon The technical scheme that the carbon content in the oxide catalyst is 0.02-8% by weight has better solved the problem of high styrene loss rate in the prior art

[0007] Chinese patent CN101475439A proposes a method for selective hydrogenation of phenylacetylene using a composite bed: the hydrocarbon fraction containing phenylacetylene is used as the raw material, the reaction temperature is 15-100°C, and the weight space velocity is 0.01-100 hours -1 , the molar ratio of hydrogen / phenylacetylene is 1-30:1, and the reaction pressure is -0.08-50.MPa. Under the conditions of -0.08-50.MPa, the raw materials are sequentially contacted with the catalyst through a composite bed reactor equipped with catalyst A and catalyst B. Nickel-based catalyst A The technical scheme with a loading ratio of 0.5 to 5:1 to palladium-based or copper-based catalyst B better solves the problem of high styrene loss rate in the prior art

This makes the catalyst in industrial operation, the reaction activity is reduced, and the service life is reduced

It should be pointed out that in the actual operation of the industry, the change of water content in the reactor is often irregular, and the sudden change will cause large fluctuations in the selective hydrogenation effect of phenylacetylene, resulting in the instability of the catalyst operation.

In addition, since the C8 hydrocarbon material containing phenylacetylene contains a large amount of unsaturated hydrocarbons, it is easy to polymerize to produce colloid and other coking precursors, which will cause carbon deposition on the catalyst and affect the selective hydrogenation performance of phenylacetylene.

[0009] However, the influence of water and surface area carbon in the reaction system on the activity and stability of phenylacetylene selective hydrogenation catalysts has not been considered in the existing phenylacetylene selective hydrogenation process.

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