1,4-Butanediol (BDO) is an important organic chemical raw material, widely used in plastics, fibers, adhesives, pharmaceuticals and other fields. Its manufacturing methods mainly include acetylene method, maleic anhydride method, butadiene method, propylene method and so on. This article will introduce these manufacturing methods and their advantages and disadvantages.
I. Acetylene method
Acetylene method is a method to produce 1,4-butanediol by addition, hydrolysis, hydrogenation and other reactions with acetylene and formaldehyde as raw materials. This method has the advantages of easy to obtain raw materials and simple process, but the production process will produce a large amount of wastewater and exhaust gas, and the pressure of environmental protection is greater.
The specific steps are as follows:
1. Acetylene and formaldehyde under the action of a catalyst carry out an addition reaction to generate 1,4-butynediol.
2. 1,4-butynediol is hydrolyzed in acid hydrolysis solution to produce 1,4-butenedioic acid.
3. 1,4-Butenedioic acid undergoes a hydrogenation reaction in the presence of a catalyst to produce 1,4-butanediol.
II. Maleic Anhydride Method
Maleic anhydride method is a method to produce 1,4-butanediol by hydrogenation and hydrolysis of maleic anhydride as raw material. This method has the advantages of easy availability of raw materials and high yield, but the production process requires the use of a large amount of hydrogen and high energy consumption. The specific steps are as follows:
1. 1,4-Butanediol and maleic acid are produced by hydrogenation of maleic anhydride under the action of a catalyst.
2. 1,4-Butanediol is produced by hydrolysis of maleic acid in alkaline hydrolysis solution.
3. Butadiene method
Butadiene method is a method to produce 1,4-butanediol by oxidizing, hydrolyzing and hydrogenating butadiene as raw material. This method has the advantages of easy availability of raw materials and mild reaction conditions, but the production process requires the use of a large number of oxidizers and catalysts, and the cost is high.
The specific steps are as follows:
1. 1,4-Dihydroxy-2-butanone is generated by oxidizing reaction of butadiene under the action of catalyst.
2. 1,4-dihydroxy-2-butanone undergoes a hydrolysis reaction in an acidic hydrolysis solution to form 1,4-butanediol and acetone.
3. Acetone in the catalyst under the action of hydrogenation reaction to generate isopropanol, isopropanol again oxidized to generate acetone, acetone and 1,4-butanediol separated and recycled.
Four, propylene method
Propylene method is to propylene, carbon monoxide and water as raw materials, after carbonyl synthesis, hydrogenation, hydrolysis and other reactions to produce 1,4-butanediol method. This method has the advantages of easy to obtain raw materials, high yield, etc., but the production process requires the use of a large number of catalysts and high temperature and high pressure conditions, and the equipment investment is large. The specific steps are as follows:
1. n-Butyraldehyde and isobutyraldehyde are produced by carbonyl synthesis reaction of propylene and carbon monoxide under the action of catalyst.
2. n-butanal and isobutanal are hydrogenated to n-butanol and isobutanol under the action of catalyst.
3. n-Butanol and isobutanol are hydrolyzed in an acidic hydrolysis solution to form 1,4-butanediol.
In summary, the above four methods can be used to manufacture 1,4-butanediol, and each method has its advantages and disadvantages. In actual production, a suitable manufacturing method should be selected based on comprehensive consideration of factors such as raw material source, production cost and environmental requirements.
