Approaching Chemistry: How is maleic acid formed? What's the industrial use of it

Maleic acid is a colorless, crystalline organic compound that can be formed naturally and chemically. It is used in water treatment, food, pharmaceuticals, construction, coatings and other industries.

Nature

Maleic acid or cis-butenedioic acid is an organic compound that is a dicarboxylic acid, a molecule with two carboxyl groups. Its chemical formula is HO??CCH=CHCO??H. Maleic acid is the cis-isomer of butenedioic acid, whereas fumaric acid is the trans- isomer. It is mainly used as a precursor to fumaric acid, and relative to its parent maleic anhydride.

How maleic acid is formed

Maleic acid is mainly produced through industrial processes using various chemical methods. Maleic acid is also a naturally occurring organic acid found in a variety of fruits, including apples and cherries. And it is a by-product of metabolic processes by certain microorganisms and is a factor in the sour taste in some unripe fruits. Its main formation methods are as follows.

Catalytic oxidation of benzene: One of the most common methods involves the catalytic oxidation of benzene or other hydrocarbons containing benzene rings. The process typically uses a catalyst in air or oxygen, such as vanadium pentoxide. Benzene or its derivatives are oxidized to form maleic anhydride (C4H2O??), which is then hydrolyzed to form maleic acid. Maleic anhydride is the precursor of maleic acid.

Isomerization of fumaric acid: Fumaric acid can be isomerized into maleic acid through a chemical reaction. The process involves heating fumaric acid in the presence of a suitable catalyst, such as a mineral acid. Cis-trans isomerization converts fumaric acid to maleic acid by converting the double bond from the trans configuration to the cis configuration.

Hydrolysis of maleic anhydride: Maleic anhydride is easily obtained by the oxidation of hydrocarbons and can be hydrolyzed to produce maleic acid. The process involves adding water to maleic anhydride to break the anhydride ring, producing maleic acid.

Biological fermentation: Some strains of microorganisms have been engineered to produce maleic acid through a fermentation process. Microorganisms such as bacteria or yeast are cultured under the right conditions and their metabolic pathways are altered to produce maleic acid as a by-product.

Applications of maleic acid

Water treatment: Maleic acid and its derivatives, such as maleic anhydride and copolymers, are effective scale inhibitors. In cooling water systems, especially in industrial processes and power plants, the water may contain high concentrations of dissolved minerals such as calcium and magnesium. When water is heated or evaporated, these minerals can precipitate and form scale deposits on heat exchange surfaces, pipes, and equipment. Scale can reduce heat transfer efficiency and lead to equipment damage and increased energy consumption. Maleic acid-based inhibitors can prevent the formation of these scale deposits by sequestering mineral ions and keeping them in solution.

Food industry: Maleic acid is a new sour agent in the food industry. Adding an appropriate amount of maleic acid to food and beverages can enhance the special fruity flavor and improve the taste. Currently, maleic acid is mainly used in fruit juices, sports drinks. Maleic acid is also a pH control agent in a variety of food and beverage products. It helps food manufacturers maintain required pH levels, which is critical to ensuring food safety and stability. By controlling pH, maleic acid can extend the shelf life of certain products and prevent spoilage.

Pharmaceutical: Many amine-containing drugs are available as maleate acid salt, such as carfenazine, chlorpheniramine, pyrilamine, methylergonovine, and thioethylperazine. While maleic acid may be used to form acid addition salts with drugs to make them more stable, such as indacaterol maleate.

Architecture: Maleic acid-based adhesives are used in the construction industry to bond a variety of building materials, including wood, concrete, metal and plastics. These adhesives are valued for their strong bonding strength and durability, making them suitable for structural applications.

Coating: Maleic acid can be used as one of the components in the synthesis of alkyd resins. Alkyd resins are widely used in the production of paints, coatings and varnishes. They provide excellent adhesion, durability and weather resistance when applied to a variety of surfaces.

In summary, maleic acid can be formed through chemical reactions, microbial fermentation and natural methods. It is widely chemical supply used in various industrial fields and is one of the indispensable chemical raw materials in life. As a leading B2B platform for global chemical wholesale trade, ECHEMI.COM is serving 110,000 buyers and 22,000 suppliers across the world. Not only that, this platform provides massive chemical-related information and data to help industry players more about chemistry and make good references for your decision-making.

COMTEX_451119837/2850/2024-04-20T03:28:55