How to make plastic raw materials?
oil refiningPetroleum crackingCracking is the process of breaking down hydrocarbons with relatively large molecular weight and high boiling point under certain conditions, which are relatively small molecular weight and low boiling point hydrocarbons.Cracking under catalysis, also known as catalytic cracking.
Cracking is in the process of petrochemical production, which is higher than the cracking temperature (700 DEG to 800 DEG C, sometimes even more than 1000 degrees Celsius), making oil fractionation products (including petroleum gas) long chain hydrocarbon in the fracture process into short chain hydrocarbons such as ethylene and propylene.Cracking is a much deeper cracking. The chemical process of oil cracking is more complex, generated by pyrolysis gas is a mixture of complex components, in addition to the main products of ethylene, and propylene, isobutene and methane, ethane, butane, acetylene, hydrogen sulfide and carbon oxides. After the pyrolysis gas is purified and separated, the basic organic chemical materials such as ethylene and propylene can be obtained with the required purity. At present, petroleum cracking has become the main method of producing ethylene.
polyethyleneFor short, PE is a thermoplastic resin made by the polymerization of ethylene. Industrially, it also includes copolymers of ethylene with a small amount of alpha olefins. Polyethylene is odorless, non-toxic, feel like wax, has excellent resistance to low temperature performance (minimum temperature can reach -70 ~ -100 C), good chemical stability, erosion resistance to most acid-base (not resistant to oxidizing acid), insoluble in common solvents at room temperature, low water absorption, excellent electrical insulation properties; but polyethylene for environmental stress (chemical and mechanical function) is very sensitive, heat aging resistance difference. The properties of polyethylene vary depending on the molecular structure and density. The products of different densities (0.91 ~ 0.96g / cm3) can be obtained by different production methods. Polyethylene can be used as a general thermoplastic forming method (see plastic processing). Widely used, it is mainly used for making films, containers, pipes, monofilament, wires, cables, daily necessities, etc., and can be used as high frequency insulating materials for television, radar and so on. With the development of petrochemical industry, polyethylene production has been developed rapidly, and the output is about 1/4 of the total plastic output. In 1983, the total production capacity of polyethylene in the world was 24.65Mt, and the capacity of the equipment under construction was 3.16Mt.
