Industrial solvents ethyl formate

Before 1945, most of the supply of ethyl alcohol for industrial solvent or feedstock uses was derived from fermentation (Table 16.13). Since this time, the reliability and low cost of petrochemical routes to the product caused a rapid displacement of fermentation sources in the U.S. Since 1975, however, subsidies for fermentation alcohol have changed this. Large new fermentation units have been constructed, and distilleries formerly used for spirits production have been converted to industrial alcohol production [56]. Increased costs of American synthetic ethanol have kept its production at two-thirds of the total. The early petrochemical sources were based on the formation and hydrolysis of ethyl sulfate, but in North America, this has been replaced by the direct gas phase hydration of ethylene (Eqs. 16.18-16.20). 

Ethylene glycol in the presence of an acid catalyst readily reacts with aldehydes and ketones to form cyclic acetals and ketals (60). 1,3-Dioxolane [646-06-0] is the product of condensing formaldehyde and ethylene glycol. Applications for 1,3-dioxolane are as a solvent replacement for methylene chloride, 1,2-dichloroethane, 1,1,1-trichloroethane, and methyl ethyl ketone as a solvent for polymers as an inhibitor in 1,1,1-trichloroethane as a polymer or matrix interaction product for metal working and electroplating in lithium batteries and in the electronics industry (61). 1,3-Dioxolane can also be used in the formation of polyacetals, both for homopolymerization and as a comonomer with formaldehyde. Cyclic acetals and ketals are used as protecting groups for reaction-sensitive aldehydes and ketones in natural product synthesis and pharmaceuticals (62). 

Another classic resolution process developed by Ethyl Corp. for (S)-ibuprofen production uses (S)-(-)-a-methylbenzylamine (MAB) as the chiral base for diastereomeric salt formation 49 The difference in solubility between (S)- and (ft)-ibuprofen MAB salts is so substantial that only half an equivalent of MAB is used for each mole of racemic ibuprofen, and no seeding is needed. The process can also be performed in a wide range of solvents, and the unwanted (ft)-ibuprofen can be recycled conveniently by heating the mother liquor in sodium hydroxide or hydrochloric acid. Other designer amines have been developed for resolution of ibuprofen with good stereoselectivities,50 but these chiral amines were prepared specifically for ibuprofen resolution and are thus unlikely to be economical for industrial production. 

The formation of lactic acid and its role as a food preservative were already discussed in connection with food fermentations, where it is produced in small concentrations. It is also possible to isolate it as a neat acid to convert the acid to the corresponding esters. Ethyl and butyl esters are good solvents for polymers and resins. Ethyl lactate, for instance, is used in the electronics industry to remove salts and fat from circuit boards it is also a component in paint strippers. Ethyl and butyl esters are approved food additives. This illustrates their low toxicity. 

NaOH), leading to the formation of significant amounts of diethylated product. Under solid-supercritical fluid PTC, only traces of this by-product were detected. Moreover, the use of a weak solid base presents evident advantages in view of an industrial application of the method. It should be noted that the use of SCCO2 as a bulk solvent led to the formation of an undesired cyanoester as the main product (Fig. 13), because the carbanion formed by deprotonation of phenylacetonitrile quickly reacts with CO2, forming a carboxylate anion that is then alkylated by ethyl bromide. 

Extractive distillation can be generally used to separate close boiling liquids or azeotropes, which cannot be separated through conventional distillation process. A solvent is introduced into the distillation column to alter the relative volatility of the feed components, and to avoid the formation of azeotropes. The extracted less volatile components leave from the bottom, whereas more volatile components come out as top products in pure form. Extractive distillation can replace conventional distillation or extraction processes resulting in improved separations, reduced capital investment and energy consumption. Industrially, extractive distillation can be implemented for binary separations resolving the close boiling mixtures, namely m-xylene/ o-xylene, methyl-cyclohexane/toluene, propylene/propane, 1-butane/1,3-butadiene, and azeotropic mixtures such as iso propylether/acetone, ethyl acetate/ethanol/water, MTBE/ethanol, etc. 

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