Plastics manufacturing, chemicals used ethylene glycol

Polymers are important. Approximately 60 million tonnes are made annually. Indeed most of the organic chemicals manufactured are used to make polymers. These chemicals obviously include monomers, but indirectly the polymer industry consumes enormous quantities of organic materials for solvents, antioxidants, stabilizers, plasticizers etc. Apart from fuel (for transport and heat) and speciality chemicals like ethylene glycol (anti-freeze), pharmaceutical and agrochemicals etc., it can be stated that the end-use of most organic chemicals is in the production, directly or indirectly, of polymers. 

Ethylene (structure in Figure 13.1) is the most widely used organic chemical. Almost all of it is consumed as a chemical feedstock for the manufacture of other organic chemicals. Polymerization of ethylene to produce polyethylene is illustrated in Figure 13.4. In addition to polyethylene, other polymeric plastics, elastomers, fibers, and resins are manufactured with ethylene as one of the ingredients. Ethylene is also the raw material for the manufacture of ethylene glycol antifreeze, solvents, plasticizers, surfactants, and coatings. 

Ethylene ranks fourth in the United States in total pounds of chemicals produced each year and it is the number one organic chemical produced each year. Over 35 bUhon pounds were produced in 1997 and sold for 0.25 per pound. Sixty-Sve percent of the ethylene produced is used in the manufacture of fabricated plastics, 20% for ethylene oxide and ethylene glycol, 5% for fibers, and 5% for solvents. 

The transformation of raw materials into products of greater value by means of chemical reaction is a major industry, and avast array of commercial products is obtained by chemical synthesis. Sulfuric acid, ammonia, ethylene, propylene, phosphoric acid, chlorine, nitric acid, urea, benzene, methanol, ethanol, and ethylene glycol are examples of chemicals produced in the United States in billions of kilograms each year. These in him are used in the large-scale manufacture of fibers, paints, detergents, plastics, rabber, paper, fertilizers, insecticides, etc. Clearly, the chemical engineer must be familiar with chemical-reactor design and operation. 

Ethylene. The catalytic oxidation of ethylene to ethylene oxide based on the invention of Lefort has been practiced commercially on a large scale. Ethylene oxide has become an important organic chemical, being used in the manufacture of ethylene glycol, ethanolamines, fi-phenylethyl alcohol, plastics, plasticizers, resins, insecticides, surface-active agents, solvents, explosives, etc. 

Ethylene finds use in the manufacture of ethyl benzene, ethanol, ethylene oxide, ethylene glycol, and ethylene dichloride. About half of the ethylene produced in the United States is used for the production of high- and low-density polyethylene plastics. Other chemical raw materials made with ethylene include ethyl chloride, dichloroethane, vinyl chloride, ethyl ether, methyl acrylate, and styrene. 

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