Method for continuously esterifying plant oil deodorized distillate by fixed bed

Abstract

The invention discloses a method for continuously esterifying plant oil deodorized distillate by a fixed bed. The method comprises the steps: uniformly mixing and heating a raw material plant oil deodorized distillate and methanol with the mass percentage being over 99.5%; carrying out esterification reaction on a mixture in the fixed bed through the fixed bed filled with a strongly acidic resin catalyst, wherein the pressure in the fixed bed is controlled at 0.1-0.5MPa; adding absolute methanol into an esterification liquid, uniformly mixing and heating the mixture online, wherein the added methanol molar weight is 5-10 times of the raw material; further carrying out esterification reaction on the mixed material with methanol through the fixed bed filled with the strongly acidic resin catalyst, wherein the pressure in the fixed bed is controlled at 0.1-0.5MPa; recovering methanol and water from the obtained esterification liquid at a reduced pressure to obtain a degassed esterification liquid, wherein the water is controlled below 0.1% by mass. According to the method disclosed by the invention, the process flow is simplified, the production cost is lowered, the environmental pollution is reduced, and the production efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of oleochemical industry, relates to the industry of natural vitamin E, in particular to a fixed-bed continuous esterification method of vegetable oil deodorization distillates. Background technique [0002] The main components of vegetable oil deodorized distillate (commonly known as DD oil) are free fatty acids, monoglycerides, diglycerides, triglycerides, sterols, sterol esters, tocopherols (ie vitamin E, VE), carbohydrates, etc., which are extracted from natural High-quality raw materials of vitamin E and sterols. At present, the pretreatment method of esterification is often used to convert free fatty acids into fatty acid methyl esters to reduce the boiling point of fatty acids. Through methyl esterification, fatty acids are converted into fatty acid methyl esters with lower boiling points. The combination of fatty acid methyl esters and natural VE boiling points The difference is to realize the separ...

AI Technical Summary

Problems solved by technology

However, this process has the following disadvantages: first, after the reaction is completed, the catalyst will remain in the reaction product. At this time, it is necessary to use acid to neutralize and then remove the homogeneous acid with a large amount of water. This process not only makes the catalyst unable to Recycling, and the waste water generated will also bring greater follow-up treatment costs

[0005] Due to the reversibility of the reaction, the traditional fixed-bed esterification reactor often has an unsatisfactory single-stage fixed-bed catalytic esterification effect, the late reaction rate is slow, and the reaction is close to equilibrium. It is necessary to continuously remove the living water during the reaction process, or prolong the reaction. time, improve the conversion rate of the esterification reaction; as open literature Xi Limin et al. [Journal of China Cereals and Oils, 2006, 21 (3): 170-174] reported the use of a single-stage fixed bed strongly acidic ion exchange resin to catalyze the deodorization of esterified palm oil Distillate, under optimal conditions, only 82% conversion of fatty acids

Images