Method for cleaner production of vitamin C

Abstract

The invention provides a method for cleaner production of vitamin C. The method comprises the following steps: adding 2-keto-L-gulonic acid, methanol and a catalyst into a reaction kettle and uniformly stirring; raising the temperature to 50 DEG C to 60 DEG C; after reflowing for 2 to 5h, obtaining a gulonate methyl ester solution; raising the temperature to 60 DEG C to 68 DEG C; then introducingammonia gas at a speed of 0.18 to 0.22mL / min until pressure in the reaction kettle is raised to 0.008 to 0.012MPa; then improving the speed of the introduced ammonia gas to 0.38 to 0.42mL / min until the pressure of the reaction kettle is 0.018 to 0.02MPa, so as to obtain a vitamin C ammonium salt methanol solution; cooling to 0 to 5 DEG C and filtering to obtain a vitamin C ammonium salt solid; after dissolving the solid with de-ionized water, treating through hydrogen type ion exchange resin to obtain the vitamin C and ammonium sulfate. The method provided by the invention has moderate reaction temperature; the yield of the vitamin C is improved and the reaction time of conversion is shortened; a byproduct ammonium sulfate fertilizer is produced and wastes are changed into valuable things;meanwhile, the production cost is reduced and economic and environment-friendly benefits are realized.

Description

Technical field [0001] The invention belongs to the technical field of vitamin C preparation, and specifically relates to a method for cleanly producing vitamin C. Background technique [0002] Vitamin C, commonly known as ascorbic acid, is a catalyst in the oxidation-reduction reaction of cells. It has strong activity and can participate in various metabolisms of the human body. It can reduce the fragility of capillaries, increase the body’s resistance and prevent the occurrence of scurvy. Essential nutrients, most animals can synthesize vitamin C by themselves, but humans, apes, guinea pigs, etc. must be taken from outside. In addition, it has strong reducing ability and can be used as an antioxidant. It has been widely used in medicine and food industry. [0003] With the increase of the experimental application scope of vitamin C, the market demand is increasing day by day, and people continue to conduct research on the experimental production technology of vitamin C. The pro...

AI Technical Summary

Problems solved by technology

In the whole process, cation exchange resin is used twice to convert sodium salt into acid. The demand for resin is large, the production equipment is relatively large, and the operating system is complicated; and the regeneration process consumes a lot of acid and alkali, and discharges a large amount of high-salt wastewater.

Because in the conversion process of 2-keto-L-gulonic acid methyl ester, sodium carbonate is used as an alkali source to convert vitamin C sodium salt, and after vitamin C sodium salt is desodiumized by hydrogen ion exchange resin to generate vitamin C, hydrogen ion When the exchange resin is regenerated with acid, the acid consumption is large, and a large amount of acidified waste liquid is generated, which causes great pressure on environmental protection, significantly increases production costs, and wastes resources. It is not a green and environmentally friendly process.