Method for preparing fatty acid by using waste oil and fat

Abstract

The invention relates to a method for preparing fatty acid by using waste oil and fat. The method comprises the steps of firstly, mixing one or at least two of trichoderma longibrachiatum, cellulose and amylase to obtain composite liquid mucedine and performing high-speed shearing under normal pressure and temperature; secondly, mixing the sheared composite liquid mucedine with the waste oil and fat and cosolvent according to a certain proportion, stirring the mixture fully and performing enzymolysis; thirdly, adding a certain amount of solid acid catalyst to a enzymolysis solution to performcatalytic decomposition; and fourthly, subjecting the catalytic decomposer to oil-water separation and obtaining the fatty acid and oleic acid through vacuum multi-tower continuous distillation separation after oil phase filter pressing and recycling of solid acid catalyst, so that the discharge water phase is waste water, the water enters a waste water processing system and a discharging standard is met. According to the method, the cost of the raw material is low, the process is simple, the operation is convenient, the total yield rate of the fatty acid after acidification is high, the problems of slag-bonding and blocking of halftone screens inside a tower and acid-base pollution, the production efficiency is improved, the raw material consumption is reduced, the waste water processingdifficulty is improved, and the environment is protected effectively.

Description

technical field [0001] The invention relates to the technical field of fine chemical preparation, in particular to a method for preparing fatty acid from waste oil. Background technique [0002] Every year, there are no less than 5 million tons of waste oil in the country, which is not used, causing serious environmental pollution and clogging sewers. What's more, criminals actually use the waste oil and hog oil produced by local methods as edible oil to flow into the dining table and food industry , causing endless harm. For this reason, relevant countries in the world have legislated one after another to establish a complete set of systems for waste oil collection, transportation, storage, processing, and sales, and provide preferential support from tax policies. Among them, Japan has increased investment in this area due to natural resource constraints and obtained It has achieved very good results and ranks at the leading level in the world. [0003] Fatty acids are ba...

AI Technical Summary

Problems solved by technology

However, this method of using waste oil to prepare fatty acids still has more or less defects: one is that the mesh screen in the distillation tower is prone to slagging and clogging, requiring frequent shutdowns for maintenance, which restricts the improvement of production efficiency

The second is to use liquid acid as a catalyst, the equipment is severely corroded, and the amount of waste water is large, so it is difficult to meet environmental protection standards

The third is that a large amount of brine must be used to flush the clogged sieve of the distillation column, resulting in secondary pollution and consumption of raw materials, and the production cost is greatly increased

Fourth, due to slagging and uneven catalysis, the reaction yield and product quality are not high

The fifth is that the post-processing of the preparation process requires a lot of labor costs