Fermentation alcohol manufacture

In the manufacture of absolute alcohol by fermentation, the product is separated and purified using several stages of distillation. In the first stage, a mixture of 5 mol per cent ethanol in water, with traces of acetaldehyde and fusel oil, is concentrated to 50 mol per cent. The concentration of alcohol in the wastewater is reduced to less than 0.1 mol per cent. 

Aqueous solutions of these alcohols occur when sugar solutions are fermented and may be separated by distilling the mixtures. It is a common, economically valuable process for manufacturing potable liquors and for producing industrial alcohol from fermented molasses solutions or pulp mill wastes. One of the authors (A.Y.M.) reports that design and operation of these columns is hampered by lack of vapor-liquid equilibrium data, especially for making potable liquors, where small amounts of the alcohols other than ethanol greatly affect the flavor and, therefore, the products marketability. 

In the manufacture of absolute alcohol by fermentation, the product is separated and purified using several stages of distillation. In the first stage, a mixture of... 

Acetone is obtained by fermentation as a by-product of -butyl alcohol manufacture, or by chemical synthesis from isopropyl alcohol from cumene as a by-product in phenol manufacture or from propane as a by-product of oxidation-cracking. 

The isoprene obtained in this way polymerizes to rubber when heated with catalytic agents such as acids, alkalies, or metallic sodium. The fact that fusel oil is obtained only in small quantities as a by-product in the manufacture of grain alcohol by fermentation, makes this method of preparing rubber of no technical interest. 

Note Process—Alcohol manufacture in distilleries consists of four main steps, namely, feed preparation, fermentation, and distillation and packaging (Figure 6.21). 

Most polymers can be made from renewable resources at a cost. For example polyethylene, the major commodity polymer used in packaging, was one of the earliest biopolymers. For some years ethylene was manufactured from sugar by fermentation to alcohol, followed by dehydration to ethene and, if and when the economics of alcohol manufacture justify its use as a biofuel, the polyolefins will again become biopolymers. So far as resource depletion is concerned, if fossil carbon resources were used only for the manufacture of polymers and not for energy production, the former would last for approximately 300 years based on present estimates. By that time, polyolefins will in any case probably be manufactured from renewable resources anyway for purely economic reasons. At... 

C7H6O5. Colourless crystals with one molecule of water, m.p. 253" C, sparingly soluble in water and alcohol. It occurs free in woody tissue, in gall-nuts and in tea, and is a constituent of the tannins, from which it can be obtained by fermentation or by acid hydrolysis. It gives a blue-black colour with Fe and is used in the manufacture 6f inks. On heating it gives pyrogallol. 

H2N-CH2 [CH2j3.CH(NH2) COOH. Colourless needles, m.p. 224 C (decomp.), very soluble in water, insoluble in alcohol. L-(-H)-Lysine is one of the basic amino-acids occurring in particularly large quantities in the protamine and histone classes of proteins. It is an essential amino-acid, which cannot be synthesized by the body and must be present in the food for proper growth. It can be manufactured by various fermentation processes or by synthesis. 

Until World War 1 acetone was manufactured commercially by the dry distillation of calcium acetate from lime and pyroligneous acid (wood distillate) (9). During the war processes for acetic acid from acetylene and by fermentation supplanted the pyroligneous acid (10). In turn these methods were displaced by the process developed for the bacterial fermentation of carbohydrates (cornstarch and molasses) to acetone and alcohols (11). At one time Pubhcker Industries, Commercial Solvents, and National Distillers had combined biofermentation capacity of 22,700 metric tons of acetone per year. Biofermentation became noncompetitive around 1960 because of the economics of scale of the isopropyl alcohol dehydrogenation and cumene hydroperoxide processes. 

Chemicals have long been manufactured from biomass, especially wood (sHvichemicals), by many different fermentation and thermochemical methods. For example, continuous pyrolysis of wood was used by the Ford Motor Co. in 1929 for the manufacture of various chemicals (Table 20) (47). Wood alcohol (methanol) was manufactured on a large scale by destmctive distillation of wood for many years until the 1930s and early 1940s, when the economics became more favorable for methanol manufacture from fossil fuel-derived synthesis gas. 

A pilot plant ia India has been estabUshed to extract fiber, pulp, and juice from the leaves of sisal plants. The fiber is sold direcdy or used to manufacture rope, the cmshed pulp is used ia paper processiag, and the juice is an excellent source of hecogenin. During a three- to five-day fermentation of the juice, partial enzymatic hydrolysis causes hecogenin to precipitate as the hemisaponin ia the form of a fine sludge. This sediment is hydrolyzed with aqueous hydrochloric acid, neutralized, and filtered. This filter cake is washed with water and extracted with alcohol. The yield of hecogenin varies between 0.05 and 0.1% by the weight of the leaf (126). 

Alcohol dehydrogenase (5) and leucine a-ketoglutarate transaminase (33,34) contribute to the development of aroma during black tea manufacturing. Polyphenol oxidase and peroxidase are essential to the formation of polyphenols unique to fermented teas. 

Others. The only top-fermented beer ia Scandinavia is Hvidt Lp. it has a low alcohol content (2.6% vol), a high level of extract, and is very mildly hopped. Smoke Beer is manufactured ia Germany and Denmark. It is made entirely from malt that is dried by direct beechwood fumes. In Denmark it is called Skibs Lp. (Ships Beer) and for centuries was iatended for consumption ia the Danish Navy and Marines siace it had better keeping quahties than the ordinary beers. It is top-fermented with low alcohoHc content. 

Irish Whiskey. Irish whiskeys are blends of grain and malt spirits three or more years of age that are produced in either the RepubHc of Ireland or Northern Ireland and comply with the respective laws regulating their manufacture. Since no peat is used in the malting process, Irish whiskey lacks the smokey character of Scotch. In the manufacturing process, the malt is soaked in water and milled to produce the wort. The fermentation usually takes about 60 hours. The first distillation in a pot stiU yields a 22—23% alcohol product. A second pot stiU distiUation produces a product that is 45—46% alcohol. This is foUowed by a third distiUation in another pot stiU to yield the Irish whiskey of about 68—70% alcohol. 

Fungi are microscopic nonphotosynthetic plants which include in their classification yeast and molds. Yeasts have a commercial value as they are used for fermentation operations in distilling and brewing. When anaerobic conditions exist, yeasts metabolize sugar, manufacturing alcohol from the synthesis of new cells. Alcohol... 

Fermentation An anaerobic bioprocess. An enzymatic transformation of organic substrates, especially carbohydrates, generally accompanied by the evolution of gas as a byproduct. Fermentation is used in various industrial processes for the manufacture of products (e.g., alcohols, organic acids, solvents, and cheese) by the addition of yeasts, moulds, and bacteria. 

The manufacture by fermentation and/or distillation of alcoholic beverages containing a wide range of organic materials including acids, whose effect it would be difficult to assess, is traditionally carried out in copper plant, and this has found full consumer acceptance. 

Uses. Nearly half the ethyl alcohol produced in petrochemical plants (not the stuff fermented for human consumption) is used as a chemical intermediate in the manufacture of ethyl acrylate, ethyl amines, ethyl acetate (when you pop the cap on nail polish remover, you smell ethyl acetate), ethylene chloride, glycol ethers, acetaldehyde, and acetic acid. However, you will see in the chapters on acetaldehyde and acetic acid, there are now more competitive routes than those based on ethyl alcohol. 

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