Manufacturing Methods of Maleic Acid
Maleic acid, also known as maleic acid, is an important organic chemical raw material, widely used in the production of unsaturated polyester resin, pesticides, pharmaceutical intermediates and other fields. There are mainly the following manufacturing methods of maleic acid:
1. Petrochemical route
The petrochemical route is to use benzene as raw material, and obtain maleic acid through oxidation, carboxylation and other reactions. The specific steps are as follows:
(1) Benzene oxidation: benzene and oxygen under the action of catalyst undergo oxidation reaction to produce maleic aldehyde.
(2) Hydrogenation of maleic aldehyde: maleic aldehyde is hydrogenated under the action of catalyst to produce maleic acid.
The advantage of petrochemical route is that the raw materials are easy to obtain and the process is mature, but the production process will produce a large amount of waste and by-products, which will cause a certain degree of pollution to the environment.
2. Bio-fermentation route
The bio-fermentation route utilizes microorganisms to ferment carbon sources such as glucose to generate maleic acid through the metabolic pathway. The specific steps are as follows:
(1) Strain culture: inoculate the maleic acid producing bacteria in culture medium for cultivation.
(2) Fermentation: under suitable conditions, the microorganisms convert glucose and other carbon sources into maleic acid through metabolic pathways.
(3) Extraction and purification: maleic acid is extracted and purified from the fermentation broth through steps such as ion exchange and crystallization.
The advantages of the biofermentation route are environmental protection, energy saving, and the ability to utilize renewable resources, but the production process requires high requirements for microbial strains, and it is necessary to maintain the stability and activity of the strains.
3. Chemical Synthesis Route
The chemical synthesis route involves the conversion of raw materials into maleic acid through chemical reactions. One common synthesis method is to obtain maleic acid by hydrolysis reaction of maleic anhydride. The specific steps are as follows:
(1) Maleic anhydride preparation: maleic anhydride is prepared by reacting phthalic anhydride with hydrogen peroxide.
(2) Hydrolysis reaction: maleic anhydride is reacted with water to produce maleic acid.
The advantage of the chemical synthesis route is that high purity maleic acid can be obtained by controlling the reaction conditions, but the production process requires the use of a large number of chemical raw materials and catalysts, which has a certain impact on the environment.
In summary, there are various manufacturing methods for maleic acid, each of which has its advantages and disadvantages and scope of application. When choosing a manufacturing method, you need to make comprehensive consideration according to the actual situation and choose the method that best suits your production needs. Meanwhile, with the increasing awareness of environmental protection and the continuous progress of technology, the future manufacturing methods of maleic acid will pay more attention to environmental protection, energy saving and sustainability.
