New And Old Technology Of Epoxy Soybean Oil
Epoxy soybean oil is one of the most widely used polyvinyl chloride non-toxic plasticizers.
At room temperature for the light yellow viscous oil-like liquid, molecular-type c57h106o10, molecular weight of about 1000, boiling point 150 ℃ (0.5KPA), Flow Point-3 ℃, viscosity 325mpa. S, refractive index 1.473 (25 ℃), in the Water solubility <0.01 (25 ℃), water in which the solubility of 0.55% (25°c), dissolved in hydrocarbons, ketones, esters, high-grade alcohols and other organic solvents, slightly soluble in ethanol.
Stabilizer. It has good compatibility with PVC resin, low volatility and small mobility. With excellent thermal stability and light stability, water resistance and oil resistance is good, can give products good mechanical strength, weather resistance and electrical properties, and non-toxic, is internationally recognized for food packaging materials chemical process auxiliaries. This product can be used for all polyvinyl chloride products. such as all kinds of food packaging materials, medical products, a variety of films, sheets, tubes, refrigerator seals, artificial leather, floor leather, plastic wallpaper, wire and cable and other daily-use plastic products, can also be used for special inks, paints, coatings, synthetic rubber and liquid composite stabilizer.
Production technology of epoxy soybean oil
The traditional process of epoxy soybean oil
The process was prepared with benzene as solvent, sulfuric acid as catalyst, soybean oil, formic acid, sulfuric acid, and benzene as mixed liquid, and hydrogen peroxide was added to the oxidation reaction. After the reaction is completed, the waste acid water is separated and the oil layer is diluted with dilute lye and soft washed to neutral. After the oil-water separation, the oil layer is distilled, the benzene mixture is separated by condensation, the benzene is reused, the kettle fluid is reduced and the distillation is intercepted. Its process is complex.
Ii. new technology of epoxy soybean oil production
1. Reaction mechanism
The process uses hydrogen peroxide containing slightly acidic, at a certain temperature to trigger the effect. The added stabilizer acts as a stabilizing agent for the resulting peracetic acid, which ensures that the oxygen atoms released by peracetic acid can be fully contacted with unsaturated bonds in soybean oil, thus making the epoxidation reaction to the product direction. The reaction type is simple.
2. Process Flow
Adding soybean oil, formic acid, stabilizer and trace sulfuric acid in the ring-oxidizing kettle, stirring the drip and hydrogen peroxide to react. Because the whole system is exothermic reaction, the temperature is controlled by cooling water to make the epoxidation of the 60℃~70℃. After the reaction terminated static stratification, after separation of the mother liquor with dilute lye for alkali washing, and then wash with soft water to neutral. The oil layer is pumped into the dehydration kettle and the product is made after the vacuum is removed from the water. The process is simple.
3. Annual production capacity of 2000t epoxy soybean oil workshop. The key of the new process is the epoxidation process. As the reaction is exothermic, so in the process of dropping low concentration of hydrogen peroxide, the temperature will rise correspondingly, and the higher the temperature, the more intense the reaction will eventually lead to open loop and continue oxidation, so that the by-products increase, product color depth, quality decline. In order to control the droplet acceleration of hydrogen peroxide, the reaction temperature can be fluctuating in the best range in order to obtain the best product and the highest yield. In the design of the ring oxidation system, we adopt the automatic control design of the whole process of epoxidation (heating, hydrogen peroxide, cooling, heat preservation, cooling). This level of control is the most advanced in the country.
4, the new and old two kinds of production technology comparison
From the above discussion, the old process production process is long and complex, equipment, corrosion seriously, "three wastes" processing volume. Due to the cancellation of solvent benzene, the new process shortened the production process and simple, reduced the fire rating, improved the working environment, "waste" less pollution, so the fixed assets investment is much smaller than the old technology.
Third, in addition, the new process of product quality is superior to the old technology. Evaluation of the quality of epoxy soybean oil, the main index of the epoxy value of course the higher the better. But in addition to looking at the epoxy value, it depends on the thermal stability of the epoxy group. Because of the high temperature in the processing of PVC products, the epoxy group with poor thermal stability has its own open-loop rupture and has no stabilizing effect. The product of the old process produces the epoxy value is generally 6%, in 177 ℃ heats 3h Its epoxy value retention rate is above 80%. And the new process production of the product its epoxy value is greater than 6.2%, up to 6.5%, thermal stability of up to 95%, is the domestic advanced level.