Ethylene Glycol Ethan-1,2-Diol

The primary manufacturing method of making ethylene glycol is from acid- or thermal-catalyzed hydration and ring opening of the oxide. Nearly all the glycol is made by this process. Either a 0.5-1.0% H2SO4 catalyst is used at 50-70°C for 30 min or, in the absence of the acid, a temperature of 195 C and 185 psi for 1 hr will form the diol. A 90% yield is realized when 

The ethylene glycol, bp 198°C, is readily vacuum distilled and separated from the DEG, bp 246°C, and TEG, bp 288°C. The mechanism of the reaction follows the general scheme for acid-catalyzed ring openings of epoxides. 

Research is being conducted on the direct synthesis of ethylene glycol from synthesis gas. In one process very high pressures of 5,000 psi with very expensive catalysts Rhx (CO) are being studied. An annual loss of rhodium catalyst of only 0.000001% must be realized before this process will compete economically. At least five other alternate syntheses of ethylene glycol that bypass toxic ethylene oxide are being researched. 

Szmant, Organic Building Blocks of the Chemical Industry, pp. 188-264. White, Introduction to Industrial Chemistry, pp. 62-79. 

Wiseman, Petrochemicals, pp. 43-63, 102-103, 151-152, and 163-164. Wittcoff and Reuben, Industrial Organic Chemicals, pp. 88-148. 

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Diol Components. Ethylene glycol (ethane 1,2-diol) is made from ethylene by direct air oxidation to ethylene oxide and ring opening with water to give 1,2-diol (40) (see Glycols). Butane-1,4-diol is stiU made by the Reppe process acetylene reacts with formaldehyde in the presence of catalyst to give 2-butyne-l,4-diol which is hydrogenated to butanediol (see Acetylene-DERIVED chemicals). The ethynylation step depends on a special cuprous... 

Ethylene glycol (ethane-1,2-diol), a major component of antifreeze, is readily metabolized by many organisms that have the glyoxylate cycle. Can you propose a sequence of catabolic steps that can explain the catabolism of ethylene glycol ... 

The primary manufacturing method of making ethylene glycol (ethane-1,2-diol, boiling point 197.6°C, density 1.1155, flash point 127°C) is from acid or thermal-catalyzed hydration and ring opening of the oxide. 

Much the same act can be carried out with dicarboxylic acids and diols. The most famous example is the polymer of ethylene glycol (ethane-1,2-diol) and terephthalic acid, which can be made simply by melting the two components together so that water is lost in the esterification reaction. The mecha-... 

Almost all of the dimethyl terephthalate (DMT) output is consumed for the production of poly(ethylene terephthalate), PET, by transesterification with ethylene glycol (ethane-1,2-diol), mostly for fiber, film, and beverage packaging applications. 

The U.S. production of ethylene oxide is over 2 5 Mt, of which about 65% is hydrolysed to ethylene glycol (ethane-1,2-diol). Nearly 60% of the glycol is used in the production of polyethylene terephthalate and the rest in antifreeze. Di- and triethylene glycols are used in resins and for gas drying ethanolamines are used in detergents and for gas separations. 

Reduction of glycolaldehyde or glyoxal yields ethylene glycol (ethane- 1,2-diol) and the reduction of formaldehyde gives methanol. However, these compounds are not ranked among the alditols. 

Note 4 Ethene and ethylene glycol [ethane-1,2-diol] are examples of difunctional monomers, glycerol [propane-1,2,3-triol] is an example of a trifunctional monomer, and divinyl-benzene and pentaeiythritol [2,2-bis(hydroxymethyl)propane-1, .3-diol] are examples of tetrafunctional monomers. 

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