Fermentation, alcohol

Alcohol fuel vehicles Alcoholic beverages Alcoholic fermentation Alcoholic proof Alcoholism... 

Various species and many strains oiyAcetobacter are used in vinegar production (48,49). Aeration rates, optimum temperatures and nutrient requirements vary with individual strains. In general, fermentation alcohol substrates require minimal nutrient supplementation whde their addition is necessary for distilled alcohol substrates. 

The subject of fermentation alcohol has always been of considerable interest to several tropical countries, but until the oil crisis of 1973, other than Brazil (197), only India appeared to appreciate the importance of fermentation alcohol as a strategic material in its economy. Ethanol prices in India have been maintained at an extremely low level by processing cane molasses, which has been a waste product of negligible value (197). 

Worldwide ethanol demand in 1991 was about 19 x 10 L, of which the industrial demand was about 5 x 10 L. The majority of the worldwide demand was for fuel use with Brazil consuming 11.9 X 10 L in 1989 (239) and the United States consuming 3.6 X 10 L in 1990 (240). In 1991, worldwide synthetic ethanol capacity amounted to 2.04 x 10 L, with the United States having a capacity of 0.802 x 10 L, 39% of the world total (Table 2). In 1991, the total ethanol capacity in the United States was 4.67 x 10 L with an industrial demand of 0.908 x 10 L. Fermentation alcohol and imports suppHed the remainder of the industrial market not suppHed by synthetic alcohol. 

Ethanol has been used in the United States to a considerable extent as an antifreeze but it has largely been replaced for such use by ethylene glycol. The use of fermentation alcohol in automotive fuel has been discussed above. Several tropical countries consider ethanol, produced from regenerable resources, an attractive petrochemical feedstock. 

Ethanol [64-17-5] M 46.1, b 78.3 , d 0.79360, d 0.78506, n 1.36139, pK 15.93. Usual impurities of fermentation alcohol are fusel oils (mainly higher alcohols, especially pentanols), aldehydes, esters, ketones and water. With synthetic alcohol, likely impurities are water, aldehydes, aliphatic esters, acetone and diethyl ether. Traces of benzene are present in ethanol that has been dehydrated by azeotropic distillation with benzene. Anhydrous ethanol is very hygroscopic. Water (down to 0.05%) can be detected by formation of a voluminous ppte when aluminium ethoxide in benzene is added to a test portion. Rectified... 

Chemical Designations - Synonyms-. Alcohol Cologne spirit Denatured alcohol Ethanol Fermentation alcohol Grain alcohol Spirit Spirits of wine Chemical Formula CjHjOH. Observable Characteristics - Physical State (as normally shipped) Liquid Color Colorless Odor. Mild, pleasant Like wine or whiskey. (Denatured alcohol may be unpleasant). 

In some parts of the world, as in Russia, fermented alcohol can serve as a cheap source for hutadiene. The reaction occurs in the vapor phase under normal or reduced pressures over a zinc oxide/alumina or magnesia catalyst promoted with chromium or cohalt. Acetaldehyde has been suggested as an intermediate two moles of acetaldehyde condense and form crotonaldehyde, which reacts with ethyl alcohol to give butadiene and acetaldehyde. 

Synthetic ethyl alcohol (known as ethanol to differentiate it from fermentation alcohol) was originally produced hy the indirect hydration of ethylene in the presence of concentrated sulfuric acid. The formed mono-and diethyl sulfates are hydrolyzed with water to ethanol and sulfuric acid, which is regenerated ... 

Volume of yeast, % Sugar fermented, % Alcohol from total sugar, % Time, hrs. 

Hydrolysis for substrates used in fermentations Alcohol production... 

Fermentation Alcohol Fermentation Amyl Alcohol Fermentation Butyl Alcohol Ferric Ammonium Citrate Ferric Ammonium Citrate, Brown Ferric Ammonium Citrate, Green Ferric Ammonium Oxalate Ferric Chloride Ferric Chloride, Anhydrous Ferric Chloride, Hexahydrate Ferric Glycerophosphate Ferric Nitrate Ferric Nitrate Nonahydrate Ferric Sulfate... 

Figure 13.12. Concentration profiles in two kinds of distillations, (a) Purifying column for fermentation alcohol small streams with high concentrations of impurities are withdrawn as sidestreams (Robinson and Gilliland, Elements of Fractional Distillation, McGraw-Hill, New York, 1939 edition), (b) Typical concentration profiles in separation of light hydrocarbon mixtures when no substantial inversions of relative volatilities occur (Van Winkle, Distillation, McGraw-Hill, New York, 1967).

Tkac et al. [16] Ethanol Off-line monitoring of S. cerevisiae batch fermentation Alcohol oxidase (AOx) in Gluconobacter oxydans cells/covered with a cellulose acetate (CA) membrane Glassy carbon electrode/ +300mV vs. SCE Ferricyanide... 

Besides these simple fermentation alcohols, the yeast also forms higher alcohols as side products, "fusel oils," that have intense odors and play a role in wine aroma. Other components are carboxylic acids, such as tartaric and malic acids, that are important as "life-insurance" during aging of the wine. Some of the aromas perceived in wines stem from esters... 

Herraiz, T. and Ough, C. S. (1993). Chemical and technological factors determining tetra-hydro-P-carboline-3-carboxylic acid content in fermented alcoholic beverages. ]. Agric. Food Chem. 41, 959-964. 

Industrial uses of ethanol include solvents (especially for toiletries and cosmetics, coatings and inks, and detergents and household cleaners), and chemical intermediates (especially ethyl acrylate, vinegar, ethylamines, and glycol ethers). Most corn fermentation alcohol is used in fuel, industrial solvents and chemicals, and beverages. 

About 10 million gallons of the fermentation alcohol is derived from wastes such as sulfite liquor or whey, but the balance presently depends on damaged grain or sugar, crop surpluses and molasses. Relative costs of ethylene and carbohydrates will change this in a few years, but no reversal to ethanol-based ethylene is likely in this country for much longer, perhaps through 1990. ... 

There is curently a government-sponsored program to increase fermentation alcohol capacity to provide material for gasohol. The issues here are numerous and complex, and emotionally-colored evaluations are clearly evident even among those who profess to have purely scientific or technical interests. Barring a drastic rise in grain prices the program is likely to continue. 

Fermentation alcohol has been used almost entirely for beverage purposes in less developed countries. In industrialized nations, even with available ethylene, fermentation alcohol is produced from low-cost surplus and waste materials. With the shift in economics it will compete with synthetic in the latter s fields. It has a monopoly of "gasohol" for political reasons and of beverages for emotional reasons. Fermentation alcohol capacity in the United States is uncertain but is estimated at... 

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