A tubular fixed-bed reactor and its application in olefin epoxidation

Abstract

The invention provides a tube-and-tube fixed-bed reactor, which includes a shell, and an upper tube sheet and a lower tube sheet are arranged horizontally inside the casing, and vertically uniformly arranged between the upper tube sheet and the lower tube sheet A number of reaction tubes, a number of heat exchange sleeves surrounding each reaction tube are arranged between the upper tube plate and the lower tube plate, and an annular gap is formed between the heat exchange sleeves and the reaction tubes. Each is provided with a plurality of openings, and the openings are distributed in a spiral shape along the axial direction of the heat exchange casing. The invention also provides the application of the tubular fixed-bed reactor and a method for preparing propylene oxide from propylene. The tubular fixed-bed reactor provided by the present invention effectively solves the problem of large axial and radial temperature gradients in the reactor, can make the temperature distribution in the reactor more uniform, and is especially suitable for strong exothermic reactions, especially for propylene The epoxidation reaction for preparing propylene oxide has a simple structure and is easy to realize, which is conducive to realizing large-scale production and application.

Description

technical field [0001] The invention relates to the field of chemical industry, in particular to a tubular fixed-bed reactor and its application in olefin epoxidation, and also to a method for preparing propylene oxide from propylene. Background technique [0002] The tubular fixed-bed reactor is one of the commonly used reactor forms in the chemical industry, and is widely used in heterogeneous catalytic reaction processes. The characteristic of heterogeneous catalytic reaction is that the reaction speed is fast, and a large amount of reaction heat is generated during the reaction process. At present, the tube-and-tube reactors used in industry mostly adopt a shell-and-tube structure. The catalyst is packed in the tube bundle, and the reaction raw materials and the catalyst contact and react in it. heat export. However, this form of tube-and-tube reactor is only suitable for reactions with a small heat release. If the reaction is exothermic, the heat transfer will be limi...

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Problems solved by technology

However, this form of tube-and-tube reactor is only suitable for reactions with a small heat release. If the reaction is exothermic, the heat transfer will be limited by the heat transfer of the tubes and tubes. temperature gradient, which may cause some catalysts to be in a state of high temperature and serious side reactions, while some catalysts are in a state of lower temperature that cannot perform normal performance

[0003] Propylene oxide is an important class of propylene derivatives, which are mainly prepared from propylene through the epoxidation reaction of peroxides. The epoxidation reaction of propylene is a typical strong exothermic reaction. If the reaction heat cannot be removed in time, it will lead to The selectivity of the process drops sharply and can also be dangerous due to the decomposition of peroxides

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