Method for co-producing biodiesel, phytosterol and tocopherol by using grease deodorized distillate

Abstract

The invention discloses a method for co-producing biodiesel, phytosterol and tocopherol by using grease deodorized distillate. Aiming at the characteristics of high acid value and complex components of the grease deodorized distillate, fatty acid and glyceride in the deodorized distillate are reacted with methanol to generate fatty acid methyl ester (biodiesel) by adopting p-toluenesulphonic acid as a catalyst. The method comprises the following steps of: adding a small amount of sterol powder serving as crystal seeds into a reaction mixture after methyl esterification reaction, then promoting the sterol in the reaction system to form crystals through a temperature program consisting of three steps in turn, and primarily separating the sterol by methods of centrifuging, filtering and the like; and separating fatty acid methyl ester (light phase) from the reaction mixture after the primary separation of the sterol by adopting primary molecular distillation, removing triglyceride, diglyceride and glycerol (heavy phase) from the reclaimed heavy phase through molecular distillation again, performing sterol crystallization and separation on the reclaimed light phase again, and reclaiming the tocopherol from the mixture after the sterol is re-separated through anion exchange chromatography. The method has the characteristics of high extraction efficiency, mild conditions and the like.

Description

technical field [0001] The invention belongs to the technical field of coproduction of biodiesel, phytosterol and tocopherol. Background technique [0002] Deodorization distillate is a by-product of the deodorization process in the oil processing process, the amount is about 0.3% to 0.6% of vegetable oil, and its main components are free fatty acids, triglycerides, sterols, natural tocopherols and other oxides. Volatile matter, such as aldehydes, ketones, hydrocarbons, etc., in addition, there are a small amount of gum, wax, lecithin, etc. The unsaponifiables in the oil deodorization distillate are mainly phytosterols and tocopherols, which are an important source of natural phytosterols and tocopherols. Phytosterols can effectively reduce the cholesterol level in serum, prevent and treat hypertension, coronary heart disease and other diseases; they also have various physiological properties such as anti-inflammation and blocking the formation of cancer cells. The propert...

AI Technical Summary

Problems solved by technology

The disadvantages of using acid or alkali as a catalyst to produce biodiesel are: the process is more complicated, the alcohol must be excessive, the subsequent process must have a corresponding alcohol recovery device, waste liquid is removed during the generation process, and the energy consumption is high. Soap builds up and may clog pipes

But enzymatic synthesis of biodiesel also has the following problems: lipase is effective for esterification or transesterification of long-chain fatty alcohols, but the conversion rate of short-chain fatty alcohols such as methanol or ethanol is low, only 40% to 60%. ;Short-chain alcohols have certain toxicity to enzymes, which shortens the service life of enzymes; by-product glycerol is difficult to recycle, not only inhibits the reaction, but also glycerol is toxic to immobilized enzymes, shortening the service life of immobilized enzymes

However, the commonly used crystallization methods have problems such as low efficiency and long time.

The separation of tocopherol and biodiesel can be achieved by multi-stage molecular distillation, but the loss of tocopherol and the cost of separation increase with the number of molecular distillation