Propylene, chemicals from

Ethylene (as well as propylene) produced from carbon dioxide subsequently allows ready preparation of the whole array of hydrocarbons, as well as their derivatives and products that have become essential to our everyday life. Whereas the nineteenth century relied mostly on coal for energy as well as derived chemical products, the twentieth century greatly supplemented this with petroleum and nat-... 

As we learned in Chapter 8, the official production of propylene is usually about half that of ethylene, only because a large part of the propylene is used by petroleum refineries internally to alkylate gasolines. This captive use is not reported. Of the propylene used for chemical manufacture, nearly 40% is polymerized to polypropylene, to be discussed in a later chapter. Of the remaining amount of propylene, seven chemicals from the top 50 are manufactured. These are listed in Table 10.1. Their industrial manufacturing methods are summarized in Fig. 10.1. Note that four of these chemicals, cumene, phenol, acetone, and bisphenol A, are also derived from a second basic organic chemical, benzene. 

A chemically pure grade of propylene obtained from Matheson Gas Products was employed. A large excess of propylene is used in this preparation since much of the olefin is converted to polymeric products. The submitters report obtaining markedly lower yields of product when an excess of propylene was not used. 

Prior to this time, other ventures had already been operating to produce commercial quantities of aliphatic chemicals from petroleum sources. Truly commercial production of ethylene glycol had been achieved by 1925 (10) using natural gas fractions as a starting material, and even earlier (about 1920) there had been the manufacture of isopropyl alcohol from cracking plant propylene (20), which may be termed the pioneer operation on a successful, continuing basis in the sphere of aliphatic synthesis from petroleum. 

Hydration of Olefins. The earliest and still the largest production of chemicals from petroleum hydrocarbons was based on the hydration of olefins to produce alcohols by the employment of sulfuric acid. The addition of olefins to sulfuric acid to form alkyl sulfates and dialkyl sulfates takes place on simple contact of the hydrocarbons with the acid. To keep down polymerization and isomerization of the hydrocarbons, the temperature is kept relatively low, usually below 40° C. and commonly considerably lower than that (18). The strength of the sulfuric acid used depends on the olefin to be absorbed. Absorption of ethylene requires an acid concentration higher than 90%, whereas propylene and butylenes are readily absorbed in 85% acid or less. The alkyl and dialkyl sulfate solutions, on dilution and heating, are hydrolyzed to the alcohols plus small amounts of by-product ethers. After distilling off the organic products, the dilute sulfuric acid is reconcentrated and re-used. 

POSM [Propylene Oxide Styrene Monomer] A process for making propylene oxide from ethylbenzene. The ethylbenzene is reacted with oxygen and propylene in the presence of a proprietary catalyst. Developed in Russia by JSC Nizkhnekamskneftkheim and licensed exclusively by Dow Chemical Company. In 2006, 36% of the world production of propylene oxide was made by this process. See also SMPO. 

Wyandotte A process for making a mixture of ethylene and propylene glycols from propane for use as antifreeze. The propane is cracked to a mixture of ethylene and propylene these are not separated but are converted to the corresponding glycols by chlorohydrination. Developed by the Wyandotte Chemicals Corporation. 

Fig. 6.11. Manufacture of styrene and propylene oxide from ethylbenzene and propylene. ARCO Chemical (Oxirane) process.

These developments progressed steadily up to the outbreak of the second world war. This can be shown in Table I, from U.S. Tariff Commission reports on synthetic organic chemicals, which shows how the number of ethylene and propylene chemicals marketed by only one firm. Carbide and Carbon Chemicals Co., increased between 1926 and 1939. The figures are approximate. 

Attention to the propylene shortage had crystallized with the publication of a major study by Stobaugh (56) in 1967, in which he analyzed thoroughly the sources and markets for propylene. He suggested that by 1970 over-all propylene production from both refining and chemical sources would probably not exceed 19 billion lbs, and chemical demand would have increased to 7.5 billion lbs at a value of 2.5 cents/lb. Stobaugh lists both U.S. propylene producers and their plant capacities as well as propylene consumers. 

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