Process for preparing fatty acid ester sulfonate

Abstract

The invention discloses a process for preparing fatty acid ester sulfonate, which comprises: introducing a mixed gas of SO3 and air into a SO3 gas jet-type sulfonation reactor, wherein the molar ratio of the fatty acid to the SO3 is kept at 1:1.0-2.0; reacting the fatty acid with the SO3 / air mixed gas in the SO3 gas jet-type sulfonation reactor, the product of sulfonation reaction and unreacted SO3 / air mixed gas are exhaust from product outlet of the SO3 gas jet-type sulfonation reactor, performing gas-liquid separation, cooling a liquid phase and continuing to react the liquid phase to obtain alpha-sulfo fatty acid; adding the alpha-sulfo fatty acid and an fatty alcohol which has an alkyl chain with 5 or more carbon atoms into an esterification kettle with a water distributor to perform esterification under a solvent or non-solvent condition to obtain an esterified product; and adding solution of alkaline alcohol and water in a neutralization kettle, adding the esterified product into the solution of the alkaline alcohol and water to perform an neutralization reaction, and evaporating the ethanol and the solvent added in esterification to obtain the fatty acid ester sulfonate. The process has the advantages of small equipment investment, convenient operation, simple process, easy control, water and energy conservation and high production safety.

Description

technical field [0001] The invention belongs to a process for preparing fatty acid ester sulfonate, in particular to a process for preparing fatty acid ester sulfonate through sulfur trioxide sulfonation, esterification with fatty alcohol, and neutralization. Background technique [0002] In recent years, the improvement of consumers' awareness of environmental protection and conservation, as well as the increase of environmental and economic pressures, have favorably promoted the development of washing products in the direction of low-temperature washing, concentration, liquefaction, environmental protection, energy saving, water saving, and high efficiency. Sodium alkylbenzene sulfonate (LAS), olefin sulfonate (AOS), fatty alcohol ether sodium sulfate (AES) and fatty acid methyl ester sulfonate (MES), which are currently used in domestic detergents, cannot Fully meet the above requirements, so it is necessary to develop functional surfactants with good low-temperature wate...

AI Technical Summary

Problems solved by technology

The fatty acid methyl ester sulfonate (MES) being developed at home and abroad is made of C 16 / C 18 It is prepared after sulfonation of fatty acid methyl ester, the hydrophilic group is located at the end of the hydrophobic group, the Krafft point is high, the low temperature water solubility is poor, the range of the gel region is wide and the viscosity is high, which brings certain advantages to the production and application of detergents. Difficulties, especially in the production process, the esterification / bleaching and methanol recovery processes are extremely prone to explosion. The above problems have always restricted the large-scale production and application of fatty acid methyl ester sulfonate (MES)

However, due to the high freezing point of fatty acids, it is easy to solidify in the liquid distributor of the falling film reactor, which affects the uniform distribution of materials, and the viscosity of fatty acid sulfonated products is high, which tends to thicken the liquid film at the lower part of the falling film reactor, and blockage in severe cases Reactor, the above situation is more serious when sulfonating fatty acids with carbon numbers higher than 16

[0005] So far, there is no domestic literature report on the esterification of α-sulfo fatty acids with fatty alcohols with an alkyl chain carbon number not less than 6. Fang Yun et al. only mentioned R=C in their patent (application number 200810021999.2). 6 -C 22 Alkyl α-sulfo fatty acid or its mixture is esterified with methanol (the molar ratio of the two = 1:7~40, the reaction is 2~10h under reflux)