A hydrogenation method for a polymer comprising an olefin unsaturated bond

Abstract

A hydrogenation method for a polymer comprising an olefin unsaturated bond is disclosed. The method includes bringing a solution of the polymer comprising the olefin unsaturated bond into contact with hydrogen in reactors under a hydrogenation condition and with the existence of a hydrogenation catalyst. The method is characterized in that the reactors are at least two reactors in series connection, the first reactor is formed by combining a tower reactor or a stirring reactor with a static mixer, materials in the reactors are allowed to be in a near complete mixing state through controlling the recycle ratio of the first reactor, the recycle ratio of the first reactor is 1-40:1, the second and latter reactors are tower reactors, and materials in the second and latter reactors are in a near plug-flow state. The method can allow the hydrogenation degree of the polymer to reach an ideal value stably.

Description

technical field [0001] The invention relates to a hydrogenation reaction method for polymers containing olefinic unsaturated bonds. More specifically, the present invention relates to a method for hydrogenating a polymer solution containing olefinic unsaturated bonds by using a series combination of a loop reactor and a tower reactor in the presence of a hydrogenation catalyst and hydrogen. Background technique [0002] Polymers containing unsaturated bonds have poor thermal and oxygen stability and aging resistance. Therefore, the unsaturated bonds of polymers are often saturated by hydrogenation, thereby greatly increasing their stability. It is generally required that the degree of unsaturation of the conjugated diene-containing segment in the polymer after hydrogenation be less than 2% by weight (ie, the degree of hydrogenation is greater than 98% by weight) in order to achieve significant performance improvements. Polymer hydrogenation is usually carried out in the pre...

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Problems solved by technology

Although the inventive method has a fast hydrogenation rate, it has the following disadvantages: the amount of hydrogenation catalyst is large and the reaction temperature is high; the liquid holdup of the trickle bed reactor is small and the utilization rate of the unit volume reactor is low; The heat transfer effect of the reactor is not good. In the initial stage of the reaction, when the concentration of double bonds in the polymer solution is high and the heat of reaction is large, it is difficult to withdraw the heat of reaction. The amplitude increases, which in turn will deactivate the hydrogenation catalyst, prolong the hydrogenation cycle or reduce the degree of hydrogenation of the final product

The disadvantage of this invention is that the reactor structure is complicated, the manufacturing cost is high and the hydrogenation degree of the final product is low

[0007] CN102477111 uses two or more reactors connected in series for polymer hydrogenation. Although the polymer can be effectively hydrogenated, the middle section of the first reactor is equipped with fillers, and the materials only stay in the filler section for a short time, causing the reactor The effective volume is greatly reduced, which greatly reduces the production capacity per unit volume of the reactor and the reaction efficiency. Moreover, a sprinkler is installed on the top of the first reactor, which makes the equipment manufacturing process more complicated.

[0008] US 4,501,875, US 4,673,714 and GB 2,159,819A all use stirred tanks for intermittent hydrogenation. Due to the high concentration of double bonds in the reaction solution in the early stage of the reaction and the fast hydrogenation rate, the heat release is large, making it difficult to control the reaction temperature. Catalyst deactivation affects hydrogenation efficiency

In addition, the batch reaction is not conducive to industrial scale-up

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