Choline Eutectic Solvent Catalytic Esterification Reactions And The Synthesis Of Biodiesel

With the rapid development of social economy, energy shortage and environmental pollution problems have become increasingly serious, Biodiesel is an alternative of fossil fuel and biofuel, has aroused widespread concern. The use of high acid value oil as a Biodiesel by two steps(preesterification deacidification, then transesterification) production of raw materials, has obvious advantages in terms of cost control and environmental pollution control. The traditional pre esterification reaction using concentrated sulfuric acid as catalyst, there are corrosion of equipment, the catalyst can not be reused, washed in acid and waste water treatment is not easy. The solid catalyst can avoid the difficult separation of toxic liquid acid and solid acid waste, but the high cost and the reaction conditions, which restrict its development. Based on the above reasons, both at home and abroad have begun to study the application of deep eutectic solvents as catalyst to reduce the production cost of biodiesel, reduce the pollution of the environment.In this paper, by using choline chloride / methyl sulfonic acid type of eutectic solvent(DES), free fatty acid catalytic esterification of high acid value oil and raw materials in the drainage oil. Discussion on the Choline Chloride / Methyl Sulfonic acid with different molar ratio on esterification were studied, and the variation of physical properties and catalytic ability; for DES, the catalytic activity and stability were discussed; the optimal condition of the esterification reaction of DES in the response surface method, and under the optimal conditions, the different acid waste synthesis of biodiesel oil, crude oil, and enlarged the experiment in a small device simulation of industrial production, DES from preparation to produce biodiesel synthesis to provide feasible reference. The research conclusions are as follows:(1) In the choline chloride / DES molar ratio of methyl sulfonic acid as catalyst had the strongest ability to synthesis of 1:2, at the same time, the different molar ratio of DES density, pH, electrical conductivity has great influence. With the increase of the molar ratio, the three physical parameters were increased.(2) In order to explore the self activity and catalytic ability of DES, raw oil for different acid catalyzed by DES, and compared with the commonly used industrial catalyst and solid catalyst, and the DES in heavy use of recycling, and found that DES is the catalytic ability of the catalyst in the strongest, and the high acid value have catalytic the effect is very good, when the DES after 6 times of repeated use, the esterification rate of change is very small, which breaks the liquid acid can reuse them.(3)The response surface method in the Choline Chloride / Methyl Sulfonic acid molar ratio was 1:2, the optimal conditions of DES catalytic esterification reaction: reaction temperature: 70℃, reaction time was 75 min, the dosage of catalyst is 3%, the ratio of alcohol to acid is 18%, the esterification rate is 99%, acid value is reduced to 1 mg KOH/g, completely to meet the needs of industry. Under the optimal conditions, drainage oil can reach the standards for biodiesel production, and has obtained good effect in the amplification experiment, comply with the requirements of production industry, reduce the industrial cost.