Manufacturing Method of Pivalic Acid
Pivalic acid is an important organic chemical raw material, which is widely used in the fields of medicine, pesticide, spice, dye and so on. This article will introduce the manufacturing method of pivalic acid, including raw material preparation, reaction process, post-treatment and so on.
I. Raw material preparation
The main raw materials for manufacturing pivalic acid are isobutyraldehyde and formaldehyde. Among them, isobutyraldehyde can be obtained through petroleum cracking or biological fermentation, while formaldehyde can be obtained through methanol oxidation or formaldehyde aqueous solution evaporation. During the preparation of the raw materials, the purity and concentration of the raw materials need to be ensured to avoid adverse effects on the subsequent reaction.
II. Reaction process
The manufacturing method of pivalic acid mainly adopts the aldol condensation method, i.e., isobutyraldehyde and formaldehyde are condensed and reacted under acidic conditions to generate pivalaldehyde, and then pivalaldehyde is converted into pivalic acid by oxidation reaction. The specific reaction process is as follows:
1. Condensation reaction
Under the action of an acidic catalyst, isobutyraldehyde and formaldehyde undergo a condensation reaction to produce pivalaldehyde and water. Commonly used acidic catalysts include sulfuric acid, hydrochloric acid and so on. The reaction temperature is generally controlled at 60-80°C and the reaction time is about 2-4 hours.
2. Oxidation reaction
The pivalaldehyde is then converted to pivalic acid by oxidation reaction. The oxidizing agent is generally hydrogen peroxide or air oxygen, etc.. The reaction temperature is controlled at 60-80°C and the reaction time is about 2-3 hours. In the oxidation process, it is necessary to control the addition rate of the oxidizing agent and the reaction temperature to avoid excessive oxidation or the occurrence of side reactions.
III. Post-treatment
After the reaction is finished, the reaction solution needs to be post-treated to obtain pivalic acid with high purity. The post-treatment process includes steps such as neutralization, extraction and distillation.
1. Neutralization
An alkaline absorbent is added to the reaction solution to react with the remaining acidic catalyst and adjust the pH to neutral. Commonly used alkaline absorbents include sodium hydroxide and sodium carbonate.
2. Extraction
The neutralized reaction solution is extracted with an organic solvent to separate the pivalic acid and the organic phase. Commonly used organic solvents include benzene, toluene, etc. The extraction process requires attention to control the extraction temperature and the ratio of solvents to improve the extraction efficiency of pivalic acid.
3. Distillation
The organic phase of pivalic acid after extraction is distilled to separate the pure pivalic acid product. The distillation temperature and pressure need to be controlled during the distillation process to avoid the decomposition of pivalic acid or the occurrence of side reactions.
Through the above steps, a pure pivalic acid product with high purity can be manufactured. It should be noted that the operating conditions and parameters of each step need to be strictly controlled during the whole manufacturing process to ensure the quality and yield of the product.
In conclusion, the manufacturing method of pivalic acid mainly includes the steps of raw material preparation, condensation reaction, oxidation reaction and post-treatment. By mastering the reasonable manufacturing process and operating techniques, high quality products of Pivalic Acid can be manufactured, providing important raw material support for pharmaceuticals, pesticides, spices, dyes and other fields.
