Ethylene industry, growth

The rapid growth of styrene after World War II was due to the widespread use of its derivatives, principally synthetic rubber and plastics. Styrene ought to be called one of the basic building blocks of the petrochemicals industry. But you get all mixed up with semantics because its made up of two other basic building blocks, ethylene and benzene. Nonetheless, it is the most important monomer in its class. 

Most addition polymers are formed from polymerizations exhibiting chain-growth kinetics. This includes the typical polymerizations, via free radical or some ionic mode, of the vast majority of vinyl monomers such as vinyl chloride, ethylene, styrene, propylene, methyl methacrylate, and vinyl acetate. By comparison, most condensation polymers are formed from systems exhibiting stepwise kinetics. Industrially this includes the formation of polyesters and polyamides (nylons). Thus, there exists a large overlap between the terms stepwise kinetics and condensation polymers, and chainwise kinetics and addition (or vinyl) polymers. A comparison of the two types of systems is given in Table 4.1. 

Only a few of the major developments can be traced here, yet these should give a fair idea of the magnitude and importance of the aliphatic petrochemical growth. It is well to remember that some of the chemistry involved in this industry is old. Four Dutch chemists, otherwise unrecalled today, prepared ethylene dichloride by addition of chlorine to ethylene in 1795, and the synthesis of ethyl alcohol from ethylene via sulfuric acid absorption was studied by Berthelot in 1855 (8). Of course, this was coal-gas ethylene, and the commercial application of this synthesis did not occur until 75 years later, in 1929, when ethylene produced from natural gas was first converted into ethyl alcohol on a practical scale (84). 

A major trend in industrial chemistry has been an emphasis on improved processes for the production of major chemicals such as ethylene, propylene, vinyl chloride, styrene, alkylene oxides, methanol, terephthalates, and so on. The necessity for higher efficiency, lower cost processes has been accentuated by the relatively slow growth rates of major industrial chemicals over the past two decades or so. The fertilizer portion of the agricultural chemicals market as described in Table 2.6 is an example of the slow growth. 

In 1999, U.S. consumption of ethylene glycol totaled 5.5 billion lb. Of that, 1.5 billion lb (28%) was used in the production of polyester bottles, primarily for soft drinks. Polyester fiber applications accounted for 1.4 billion lb (26%), primarily for the textile industry. Polyester film and miscellaneous applications consumed another 0.4 billion lb (7%). Antifreeze applications have held steady at approximately 1.6 billion lb over the last 20 years, and have become relatively less important with time than the polyester applications. This trend is expected to hold in the future. Increased demand for polyester bottles is expected to fuel growth in the United States, and bottle and textile applications are expected to fuel growth in other areas of the world. 

In addition, the propylene growth rate is faster than ethylene s and the typical C3=/C2= ratio from the naphtha steam cracker is about 0.43. Because the European and Asian demand, Figure 5.20, is for a C3=/C2= ratio of about 0.70, it is inevitable that propylene will have to be produced in greater quantity by the FCC unit to supply the chemical and plastic industries. 

The past ten years has seen a spectacular growth in the Indian petrochemicals and polymer industries so that today India is a major player in the region. India now has a nominal ethylene capacity of 2.5 million tonnes of ethylene, which places it fifth in terms of capacity in the Far East. 

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