Studies On Synthetic Technology Of Beta Carotene

β-carotene is a kind of vitamin A raw with a color, promote reproduction function, and it can be used as a raw material for producing canthaxanthin. What’s more, β-carotene is also widely used in food additives, feed additives and pharmaceutical products areas which lead a broad market prospects. Researching the efficient synthesis process has an important significance.On the basis of literature research, we choose the synthesis routes, which based on a typical Witting-Horner reaction C15+C10+C15. With fifteen carbon phosphoric acid diethyl ester as the starting material, condensation reaction can be occered with ten carbon triene dialdehyde in the alkaki environment to give the all-trans P-carotene. The process route uses C15 phosphate ester instead of C15 triphenylphosphine salt to avoid the use of triphenylphosphine and the generation of triphenylphosphine oxide. it is a pretty mild, environmental friendly technology. But the process has large disadvantagements of low yield, high residual solvent, tedious post processing, applying anhydrous toluene, etc.In order to solve these problems, and seek a better all-trans β-carotene prime industrial production route, this paper produced a series of detailed study and optimization. The main contents are as follows:In this paper, we research the β-carotene production in the specific process parameters to determine the optimum reaction conditions. Sodium dimethyl sulfoxide can be used as the better alkali during the rearrangement process. The optimum of preparation temperature is 70 to 75℃ and reaction time is 5～6 h. After the reaction, the system requires cooling and the optimum cooling temperature is 20～25℃. The optimum reaction temperature of the rearrangement process is 0～5℃. The raw material of sodium hydride and the ten-carbon triple ene dialdehyde optimum ratio of 2.6 to 2.7, in this step yield of the product was 85.0%. At the same time, the post treatment process was improved, and the better post-processing mode is extracted with toluene. The new scheme effectively improved the yield and purity of the product, and reduced the number of post-processing.To solve the residual solvent and improve the quality of products. In this paper, we research the residue solvent problem of (3-carotene pigment production. Using cyclohexane as solvent to replace residual toluene, and the replacement process parameters were optimized to obtain optimal dissolution temperature about 70～75℃ while the solvent multiples is of 28 to 30. What’s more, the product yield is up to 80%, and the residual toluene reduced to 0.089% or less. At the same time, we investigate the effects of each process parameter about the β-carotene translocation process to the suitable transposition condition:solvent of ethanol, more indexing temperature of 70～80℃, optimum translocation time for 10 hours. After purification, the quality of beta carotene was in accordance with GB, EP and USP standards.The pilot test of β-carotene was studied in this paper, and through the organic membrane dehydration, the problem of toluene treatment was solved. By means of pilot scale test, the optimum technological parameters were determined. The total yield of β-carotene was 68%. Toluene containing traces of low-boiling impurities was pre-treated to a mixture of 98.5% of aqueous toluene, and then the organic film is dehydrated to give a content of 98.9%, moisture content lower than 0.02% by dry toluene. The toluene was applied in order to achieve naturally. It is determined that the process is suitable for mass production by means of pilot scale production.