10-第十章 醇与醚.ppt
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有机化学;第十章 醇和醚(上);Until the 1920s, the major source of methanol (甲醇) was as a byproduct in the production of charcoal (碳) from wood—hence, the name wood alcohol. 1920年以前,甲醇的主要来源是木头制造碳的副产品。因此也叫木醇。;When vegetable matter ferments(发酵), its carbohydrates are converted to ethanol(乙醇) and carbon dioxide(二氧化碳) by enzymes(酶) present in yeast(酵母). Fermentation of barley(大麦) produces beer; grapes give wine. The maximum ethanol content is on the order of 15%, because higher concentrations inactivate the enzymes, halting fermentation. Distillation of the fermentation broth can be used to give “distilled spirits” of increased ethanol content. Whiskey is the aged distillate of fermented grain and contains slightly less than 50% ethanol. Brandy and cognac are made by aging the distilled spirits from fermented grapes and other fruits. The characteristic flavors, odors, and colors of the various alcoholic beverages depend on both their origin and the way they are aged.
当蔬菜类物质发酵时,其中的碳水化合物在酶中酵母的作用下转化为乙醇和CO2. 大麦发酵可以制啤洒,萄葡发酵可以制葡萄酒。乙醇的最大含量可以达到15%,高浓度的乙醇可以使酶失活而停止发酵。蒸馏发酵的汤可以得到蒸馏酒来提高乙醇含量。威士忌是小麦发酵后蒸馏的,乙醇含量略小于50%. 白兰帝和cognac(白兰地酒的一种)是葡萄与其它水果发酵后蒸馏的酒。酒精性饮料特征性的味道、风味和颜色取决于乙醇的来源和发酵方法。
Synthetic ethanol is derived from petroleum by hydration of ethylene. It is relatively inexpensive and useful for industrial applications. To make it unfit for drinking, it is denatured by adding any of a number of noxious materials, a process that exempts it from the high taxes most governments impose on ethanol used in beverages.
合成乙醇来自于石油中的乙烯氢化。这种乙醇相对便宜适合于工业应用。为了使它不适合饮用,常人为加入一定量的有害的材料。工业乙醇可以使它免除政府征收的乙醇用于饮料行业的高税率。;When vegetable matter ferments(发酵), its carbohydrates are converted to ethanol(乙醇) and carbon dioxide(二氧化碳) by enzymes(酶) present in yeast(酵母). Fermentation of barley(大麦) produces beer; grapes give wine. The maximum ethanol content is on the order of 15%, because higher concentrations inactivate the enzymes, halting fermentation. Distillation of the fermentation broth can be used to give “distilled spirits”
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