Technological process for continuously producing succinic anhydride and co-producing succinic acid through maleic anhydride hydrogenation

Abstract

The invention discloses a technological process for continuously producing succinic anhydride and co-producing succinic acid through maleic anhydride catalytic hydrogenation. The whole process comprises three steps, namely, reaction, rectification and hydrolysis, wherein two stages of hydrogenation reactors are used for reaction, a primary hydrogenation reactor is a fixed bed reactor with hydrogen entering from the lower part and reaction liquid exiting from the upper part, and a secondary hydrogenation reactor is a trickle bed reactor with hydrogen and reaction liquid entering from the upper part and exiting from the lower part. The technological process adopts an external circulating heat radiation manner, and reaction heat is uniformly removed, so that the average operation temperature of the whole reactor is effectively controlled, and the reaction temperature in the whole main reactor is balanced. Furthermore, the primary hydrogenation reactor adopts the manner that both the maleic anhydride solution and hydrogen flow upward simultaneously, so that the reaction temperature of the whole reactor is controlled to be balanced, local hot spot temperature is effectively controlled and lowered, and the reactants are prevented from polymerizing and depositing carbon or coking.

Description

technical field [0001] The invention relates to a production process of succinic anhydride / succinic acid, and specifically belongs to a large-scale industrialized continuous production of succinic anhydride and succinic acid with maleic anhydride as a raw material. Background technique [0002] Succinic acid, also known as succinic acid, can be obtained by hydrolysis of succinic anhydride. It is an important synthetic intermediate and food flavoring agent, widely used in medicine, pesticides, fine chemicals, alkyd resin and other fields. In recent years, due to the application of succinic acid in the fields of fully biodegradable plastic polybutylene succinate (PBS) and organic coatings, its demand has increased greatly. It is estimated that my country's PBS industry alone will require 2.05 million tons of succinic acid per year in the future. [0003] The production methods of succinic acid mainly include: biological fermentation method, electrolytic reduction method and c...

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Problems solved by technology

This method is suitable for removing the reaction heat of a smaller reaction device. If the reaction device is enlarged, the heat transfer pipe will not only be unable to remove the reaction heat evenly, but will also affect the distribution of the reaction liquid in the reactor, thereby reducing the catalyst reaction performance.

ZL 201110235411.5 controls the hydrogenation reaction temperature by installing a cooler in the middle of the catalyst bed of the trickle bed reactor, and then synthesizes succinic anhydride with high selectivity. This method can effectively control the temperature of the catalyst bed, but when the raw material solution When the concentration of maleic anhydride increases to increase the capacity of a single reactor, it is easy to form extremely high temperatures at the hydrogenation sites on the surface of the catalyst, resulting in sintering of active components of the catalyst or coking of organic matter polymerization

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