A kind of method for preparing p-toluenesulfonic acid by toluene sulfonation

Abstract

The invention discloses a method for preparing p-toluenesulfonic acid through toluene sulfonation in a micro-reactor. The method is characterized in that a low-concentration liquid SO3 is taken as a sulfonating agent, an excess feeding ratio of toluene to SO3 is employed, and in the sulfonation technology, a high-concentration toluene is used for feeding and a product mother liquor (filtrate) is cycled. Also, a micro-channel in-situ heat exchange technology is employed for precisely regulating the sulfonation reaction temperature. The method has the advantages that liquid sulfur trioxide is taken as the sulfonating agent, no waste acid is basically generated in products, separation is easy to operate, the concentration of the main product p-toluenesulfonic acid is 97%, and the micro-reaction sulfonation technology is safe and continuous in process and high in efficiency.

Description

technical field

[0001] The invention belongs to the technical field of synthesis of fine chemical raw materials, and in particular relates to a method for preparing p-toluenesulfonic acid through liquid-phase sulfonation of toluene in a microreactor. Background technique

[0002] Sulfonation reaction occupies an important position in the field of modern chemical industry, and is an important step in the synthesis of various organic products. It is widely used in industries such as medicine, pesticides, dyes, detergents and petroleum. Sulfonation reaction is a kind of reaction that introduces sulfonic acid groups into aromatic hydrocarbon compounds. After the introduction of sulfonic acid groups, organic compounds have specific functions such as water solubility, easy transformation, and hydrolysis. Correspondingly, sulfonated products can be directly used as surfactants Product application, or continue to convert as an intermediate product into intermediates or products cont...

Images