Manufacturing method of butadiene for industrial use
Abstract:
This paper describes the manufacturing method of butadiene for industrial use, focusing on the preparation of butadiene by catalytic dehydrogenation method using ethylene and butene as raw materials. The method has the advantages of easy availability of raw materials, mild reaction conditions, high selectivity, and is suitable for large-scale production. By elaborating the reaction principle, process flow and catalyst selection, it provides theoretical guidance for the production of butadiene.
I. Introduction
Butadiene is an important chemical raw material, widely used in synthetic rubber, plastics, fibers and other fields. With the rapid development of chemical industry, the demand of butadiene increases year by year. Therefore, it is of great significance to study the manufacturing method of butadiene to improve the production efficiency and reduce the production cost to promote the development of chemical industry.
II. Manufacturing Methods of Butadiene for Industrial Use
1. Catalytic Dehydrogenation Method
Catalytic dehydrogenation method is to generate butadiene by dehydrogenation reaction under the action of catalyst using ethylene and butene as raw materials. This method has the advantages of easy availability of raw materials, mild reaction conditions, high selectivity, etc., and is suitable for large-scale production.
(1) Reaction principle
The main reaction of catalytic dehydrogenation method is:
C2H4 + C4H8 → 2C4H6
The reaction is heat-absorbing and needs to be carried out under high temperature conditions. The role of the catalyst is to reduce the activation energy of the reaction and improve the reaction rate and selectivity.
(2) Process flow
The process flow of catalytic dehydrogenation method mainly includes the steps of raw material pretreatment, dehydrogenation reaction, product separation and refining. The specific process is as follows:
a. Raw material pretreatment: ethylene and butene are mixed in a certain proportion, preheated and desulfurized to ensure the activity and stability of the catalyst.
b. Dehydrogenation reaction: The pre-treated feed gas is introduced into the dehydrogenation reactor, and the dehydrogenation reaction is carried out under the action of catalyst. The reaction temperature is typically in the range of 600-650°C and the pressure is in the range of 0.1-0.5 MPa.
c. Separation of products: The dehydrogenation reaction products are cooled and separated to obtain crude butadiene and unreacted ethylene and butene.
d. Refining: The crude butadiene is subjected to a refining process to remove impurities and obtain the higher purity butadiene for industrial use.
(3) Catalyst selection
The catalysts for catalytic dehydrogenation method are mainly platinum system, nickel system and iron system. Among them, platinum catalyst has higher activity and better selectivity, but the price is expensive; nickel catalyst has relatively lower price, but the activity and selectivity are slightly inferior to platinum; iron catalyst has lower activity but better selectivity, which is suitable for dehydrogenation reaction of low concentration ethylene and butene. According to the specific production conditions and requirements, choose the suitable catalyst.
2. Other Manufacturing Methods
Besides catalytic dehydrogenation, there are other methods available in the industry for the preparation of butadiene, such as cracking and extraction. These methods have their own advantages and disadvantages and are suitable for different production conditions and requirements. Conclusion
The manufacturing method of butadiene for industrial use is mainly catalytic dehydrogenation, which has the advantages of easy availability of raw materials, mild reaction conditions, high selectivity, etc. and is suitable for large-scale production. In actual production, suitable manufacturing methods and catalysts should be selected according to specific conditions and requirements to improve the production efficiency, reduce the production cost and promote the development of chemical industry.
