| 摘要 |
Organic compounds are produced by reacting gases with or while in contact with a liquid circulating in a liquid ring pump (see Division B1). Acetic anhydride is obtained by reacting ketane in the form of a gas obtained by the thermal cracking of acetic acid with acetic acid, the gas being sucked into a liquid ring pump under a vacuum of 33TORR and which contains a circulating mixture of acetic acid and acetic anhydride maintained at about 30 DEG C. by cooling. Fresh acetic acid is added to the circulating liquid to maintain 13% acetic acid in the circulating liquid and some circulating liquid is withdrawn continuously to remove the acetic anhydride formed. Methyl-ketene and iso-propyl-ketene may be similarly reacted with propionic and iso-valeric acids to produce propionic and iso-valeric anhydride respectively. In another example a liquid ring pump is used to react methyl-ketene with chlorine in a -chloropropionyl chloride cooled to 0 DEG C. as circulating liquid. In the production of ethylene bromide, ethylene and bromine vapour were sucked into a liquid ring pump under a vacuum of 85TORR and passed into a circulating liquid consisting of hexachlorobutadiene maintained at about 15 DEG C. Hexachlorobutadiene may be added to the circulating liquid to replace that withdrawn together with the ethylene bromide or ultimately the ethylene bromide may constitute the circulating liquid. b -Aminocrotonic acid ethyl ester is made by reacting ammonia with ethyl acetoacebate in a liquid ring pump containing b -aminocrotonic acid ethyl ester maintained at 35 DEG C. as circulating liquid, some of the circulating liquid being withdrawn continuously. In the production of paraldehyde, acetaldehyde vapour is sucked into a liquid ring pump in which paraldehyde maintained at 20 DEG C. is circulated and to which 1% of sulphuric acid has been added as a catalyst. Freshly formed paraldehyde is run off continuously.ALSO:In a method of absorbing or dispersing and reacting gases in liquids, the absorbing or dispersing and reacting is carried out simultaneously in a liquid ring pump, the circulating liquid of which contains the reactants. The circulating liquid may be a reaction product or an inert liquid of low vapour pressure in which the reactants are present in suspension, emulsion or solution. The gas or gases being reacted may be sucked into the pump under a vacuum of e.g. 85 TORR. Catalysts may be added to the circulating liquid and the liquid may be heated or cooled. The reaction product may be withdrawn continuously at a rate corresponding to the rate of formation. The method may be used for reacting gases with gases or gases with liquids. Examples of reactions carried out by the method include producing acetic anhydride from ketone and acetic acid, reacting organic compounds with ammonia or halogens and polymerizing acetaldehyde in the presence of sulphuric acid as a catalyst (see Division C2). |
