Fatty alcohol ether carboxylic acid preparation method

Abstract

The invention discloses a fatty alcohol ether carboxylic acid preparation method which comprises the following steps: the first step, mixing fatty alcohol ether with deionized water, adding alkali, warming and reacting, then adding a catalyst, keeping pressure under the oxygen environment to react, finishing reacting until oxygen pressure does not change again, extruding a material mixed solutionand generating alcohol ether carboxylate; the second step, performing suction filtration on the mixed solution obtained in the first step to obtain filtrate and filter cake, utilizing deionized waterto wash the filter cake and storing the filter cake in alkali liquor to be applied to the next oxidizing reaction, wherein the filtrate is a fatty alcohol ether carboxylate solution; the third step, adding acid into the filtrate obtained in the second step, warming ad reacting, then adding inorganic salt to be stirred evenly, standing and layering and obtaining fatty alcohol ether carboxylic acidfrom the upper layer. The fatty alcohol ether carboxylic acid preparation method disclosed by the invention has the advantages of simple technological process, production process easy to control, highproduct purity, stable quality, green and environment-friendly production process, quick reaction speed, low energy consumption and more economic production process.

Description

technical field [0001] The invention belongs to the technical field of surfactant preparation, and relates to a method for preparing fatty alcohol ether carboxylic acid by an oxidation method, in particular to a process for preparing fatty alcohol ether carboxylic acid by using a series of fatty alcohol ethers as raw materials and using carbon-loaded noble metals as catalysts. Background technique [0002] Fatty alcohol ether carboxylic acid (AEC) series products are anionic surfactants, which are the three green surfactants in the 1990s. They are mild, safe to use, and easy to biodegrade, and are known as environmentally friendly surfactants. It can be used as a good detergent, wetting agent, dispersant, foaming agent, mildness modifier, etc., and can be used in cosmetics, household and industrial cleaning, textiles and other industries. Due to the change of the public consumption concept, people pay more and more attention to the safety, mildness, skin feeling, conditionin...

AI Technical Summary

Problems solved by technology

After the reaction is finished, the catalyst is recovered by filtration and reused again, and the filtrate is the product of high-conversion alcohol ether carboxylate. In order to maintain a low system viscosity and stable pH, this method adopts the method of continuously adding alcohol ether and alkali, which is cumbersome to operate. The process is not easy to control

[0006] Patent US5490936 discloses the recovery method of alcohol ether carboxylate catalyst prepared by oxidation method. In the process of synthesizing alcohol ether carboxylate, as the carbon chain length of raw material alcohol ether increases, the viscosity of the system increases, resulting in difficulty in the recovery of precious metal catalysts. Generally, it is commonly used The method is to first filter, then add several times of acetone in the filtrate to remove the residual dissolved catalyst in the filtrate by precipitation and filtration, but this treatment will lead to weakening of the catalyst activity, and not only the economy is poor, but also the environment will pollute. The method applied for in the patent is that the reaction liquid enters the liquid reservoir and is pumped into the cross-flow filter. There is a membrane inside the cross-flow filter, and the carrier is aluminum oxide and zirconium dioxide. Plastic and activated carbon can also be used as the carrier. When the catalyst suspension passes through the cross-flow reactor, about 70% is filtered, and the remaining 30% is returned to the reactor with the catalyst for reuse

The advantage of this invention is that there is no need to add a solvent to reduce the viscosity, and the catalyst can be recycled without expensive methods, but the catalyst must be reused together with the feed liquid, which greatly reduces the production efficiency, and at the same time increases the proportion of by-products and reduces the catalyst activity.

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