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Catalytic distillation is a branch of reactive distillation which combines the processes of distillation and catalysis to selectively separate mixtures within solutions. Its main function is to maximize the yield of catalytic organic reactions, such as the refining of gasoline. The earliest case of catalytic distillation was thought to have dated back to 1966;〔(【引用サイトリンク】first=Achim )〕 however, the idea was officially patented in 1980 by Lawrence A. Smith, Jr.〔(【引用サイトリンク】first=Lawrence A. )〕 The process is currently used to purify gasoline, extract rubber, and form plastics. ==Catalysts== The catalysts used for catalytic distillation are composed of different substances and packed onto varying objects. The majority of the catalysts are powdered acids, bases, metal oxides, or metal halides. These substances tend to be highly reactive which can significantly speed up the rate of the reaction making them effective catalysts.〔(【引用サイトリンク】first=Lawrence A. )〕 The shapes which the catalysts are packed onto must be able to form a consistent geometric arrangement to provide equal spacing in the catalyst bed (an area in the distillation column where the reactant and catalyst come into contact to form the products). This spacing is meant to ensure the catalysts are spread evenly within the column. The catalyst bed must be largely spacious (about 50% empty) so that any evaporated gaseous reactants may catalyze and form gaseous products. The catalyst bed must also be able to contract and expand as it may have to respond to pressure changes within the column.〔(【引用サイトリンク】first=Lawrence A. )〕 Before the catalysts are packed onto the shape, they are first packed onto something porous like a cloth or wire mesh. The cloth may be made from cotton, fiberglass, polyester, nylon, or other similar materials. The mesh is generally made from aluminum, steel, or stainless steel.〔(【引用サイトリンク】first=Lawrence A. )〕 In terms of shapes, catalysts are usually packed on rings, saddles, balls, sheets, tubes, or spirals. These shapes tend to be made from fiberglass, teflon, and nonreactive metals. Before the catalysts are introduced into the system, they are either bagged, attached on metal grills or screens, or placed on polymer foams.〔(【引用サイトリンク】first=Lawrence A. )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Catalytic distillation」の詳細全文を読む スポンサード リンク
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