Isopropyl alcohol is a colorless, volatile, flammable liquid having a low order of toxicity and a mild odor. Its main uses are as a chemical intermediate and in solvent applications in medicine and industry. The majority of the isopropyl alcohol in the United States is produced by indirect hydration of propylene in the weak sulfuric acid process. Outside the United States, several acid‐catalyzed direct hydration of propylene processes are also used. The indirect process can use refinery‐grade propylene streams and lower operating pressures than the direct process, but suffers from higher corrosion and maintenance costs. These processes and the various catalysts employed are described. Isopropyl alcohol demand in the United States has been declining slowly since 1983. Demand is expected to grow slightly owing to increasing use as a chemical intermediate. In addition to its use in the production of acetone, isoproyl alcohol is consumed in the production of higher ketones, amines, esters, and other chemicals. The use of diisopropyl ether as a fuel oxygenate may become a significant outlet for isopropyl alcohol.

ETHANOL 1 a Refs. 6-14. b To convert kPa to atm, divide by 101.3. c To convert J to cal, divide by 4.184. d To convert C·m to debye, divide by 3.336 × 10 −30 (esu = D × 10 −18 ) .A summary of physical properties of ethyl alcohol is presented in Table 1. Detailed information on the vapor pressure, density, and viscosity of ethanol can be obtained from References 6-14. A listing of selected binary and ternary azeotropes of ethanol is compiled in Reference 15. Chemical PropertiesThe chemistry of ethyl alcohol is largely that of the hydroxyl group, namely, reactions of dehydration, dehydrogenation, oxidation, and esterification. The hydrogen atom of the hydroxyl group can be replaced by an active metal, such as sodium, potassium, and calcium, to form a metal ethoxide (ethylate) with the evolution of hydrogen gas (see Alkoxides, metal). 2 C 2 H 5 OH + 2 M −→ 2 C 2 H 5 OM + H 2 Sodium ethoxide [141-52-6] can be prepared by the reaction of absolute ethyl alcohol and sodium, or by refluxing absolute ethyl alcohol with anhydrous sodium hydroxide (16): CH 3 CH 2 OH + NaOH −→ CH 3 CH 2 ONa + H 2 O ETHANOL 3Commercially, water is removed by azeotropic distillation with benzene (17). Sodium ethoxide precipitates upon addition of anhydrous acetone (18). This strong base hydrolyzes readily to give ethyl alcohol and sodium and hydroxyl ions.Sodium ethoxide can also be prepared by the reaction of sodium amalgam with ethyl alcohol.Sodium ethoxide is used in organic synthesis as a condensing and reducing agent. The reaction between sodium ethoxide and sulfur monochloride yields diethyl thiosulfite (19).2 CH 3 CH 2 ONa + S 2 Cl 2 −→ (CH3CH2O) 2 S 2 + 2 NaCl Barbiturates (Veronal, Barbital, Luminal, Amytal), ethyl orthoformate, and other chemicals are produced commercially from sodium ethoxide.Aluminum and magnesium also react to form ethoxides, but the reaction must be catalyzed by amalgamating the metal (adding a small amount of mercury).6 CH 3 CH 2 OH + 2 Al −→ 2 (CH3CH2O) 3 Al + 3 H 2 2 CH 3 CH 2 OH + Mg −→ (CH3CH2O) 2 Mg + H 2 Well-cleaned aluminum filings react at room temperature in the presence of mercuric chloride (20, 21). In an autoclave, metallic aluminum and ethyl alcohol react without a catalyst at 120 • C (22). The reaction can also be promoted by the addition of sodium ethoxide (23). Aluminum should be avoided as a material of construction for ethanol service.Other reactions involving the hydrogen atom of the hydroxyl group in ethyl alcohol include the opening of epoxide rings to form hydroxy ethers, and the addition to acetylene [74-86-2] to form ethyl vinyl ether [104-92-2].These reactions are carried out in the presence of acidic and basic catalysts. The acid-catalyzed addition of ethyl alcohol to acetylene or to a vinyl ether produces acetals (diethers of 1,1-dihydroxyethane). The acid-catalyzed reaction of ethyl alcohol with an aldehyde or ketone also gives acetals.The hydroxyl group can be replaced by halogens from inorganic acid halides or phosphorus halides to give two different products, ethyl esters of the...

Ethanol's unique combination of physical and chemical properties has led to its use as a solvent, a germicide, a beverage, an antifreeze, a fuel, a depressant, and a chemical intermediate for other organic chemicals. Most industrial ethanol is produced from ethylene by the direct hydration process. Ethanol from fermentation processes is the second most important source. The subsidized (federal and state) use of fermentation ethanol in gasoline has fueled a rapid growth in U.S. production, which has provided some ethanol for crossover to the industrial market. The 1990 Clean Air Act requiring the use of oxygenates in gasoline has further fueled this growth. Corn is the principal feedstock for fermentation in the United States, and sugar cane is the most important raw material outside the United States. This rapid growth has also caused a renewed interest in research into this ancient process. The main uses for industrial ethanol are as an intermediate for the production of other chemicals and as a solvent. The United States Treasury, Bureau of Alcohol, Tobacco, and Firearms oversees the production, procurement, and use of ethanol in the United States.