Fumaric acid is used in the production of unsaturated polyester resin. This type of resin is characterized by good chemical resistance and heat resistance; the copolymer of fumaric acid and vinyl acetate is a good adhesive, and benzene Ethylene copolymer is the raw material technology for manufacturing glass fiber reinforced plastic. The plasticizer produced is non-toxic and can be used in food contact with vinyl acetate emulsion. This type is intermediates of fine chemicals such as pharmaceuticals and optical bleaching agents. It is used as an antidote in the production of dimercaptosuccinic acid in the pharmaceutical industry. It is neutralized with sodium carbonate to obtain sodium fumarate ([17013 -01-3]), and then replaced with ferrous sulfate to obtain ferric fumarate, which is used for medical treatment of small red blood cell anemia with iron-rich drugs. This medicine is used as a kind of food additive--sour agent, used in soft drinks, fruit candy, jelly, ice cream, etc. It is mostly used in combination with the sour agent citric acid. The monosodium salt made by the reaction of fumaric acid and sodium hydroxide is also used. As a sour seasoning, it is also used as an intermediate for synthetic resin and mordant.
Food grade fumaric acid is white granule or crystalline powder, odorless, specific sour taste, strong sour taste, about 1.5 times that of citric acid, specifications: melting point 286-287℃, sublimation at 200℃, decomposition at 290℃, 230 Above ℃, it is converted into maleic acid, and then loses water to form maleic anhydride. Boil with water to get malic acid.
Industrially, fumaric acid is mainly prepared by chemical synthesis and biosynthesis, but chemical synthesis is still the main method.
Fumaric acid production process technology method: benzene or butene and air, catalytic oxidation, hydrolysis, concentration, crystallization, finished products.
Maleic acid isomerization method
Benzene or butene (80%) and excess air are absorbed by the circulating liquid field in a fluidized bed or fixed bed reactor equipment to produce maleic acid. Under the action of thiourea catalyst, maleic acid is heated to 145-260°C through isomerization reaction to generate fumaric acid, then cooled, filtered, washed filter cake with hydrochloric acid, dried and crushed to obtain
