Abstract: Alcohols and acids are esterified by means of liquid-phase equilibrium reactions on ion exchangers in an apparatus comprising a prereactor and a rectifying column with external reactors. The process is characterized by the fact that a portion of one of the starting compounds is fed directly to the external reactors.

Abstract: The reaction gases from the chlorination of methane and preferably also methyl chloride, after removal of the HCl and drying, are subjected to the steps of partially condensing the dried stream of reaction gases at a pressure of 5-15 bars and at a temperature of 0.degree.-40.degree. C. which condenses the chloroform and the carbon tetrachloride; contacting the gaseous phase of the partially condensed stream of reaction gases in a countercurrent manner with a stream of liquid methyl chloride; recycling the stream of gases discharging from the contacting stream of liquid methyl chloride to the chlorination stage; and fractionating the contacting stream of liquid methyl chloride.

Abstract: A process for the continuous separation of methanol and water from a feed mixture containing predominantly tetrahydrofuran admixed with water, methanol and small amounts of additional compounds, in a rectifying apparatus having at last two rectifying columns, of which two are operated at different pressures which involves feeding the raw material into a first column operated under lower pressure, and introducing the distillate from the column operated under a lower pressure to a second column operated under a higher pressure, while a product stream from the second column operated under a higher pressure is reintroduced into the first column operated under a lower pressure.

Abstract: Process for the preparation of pure methyl tert.-butyl ether. Isobutene or isobutene-containing hydrocarbon mixtures are reacted with methanol in a molar ratio of 1:1 to 1:2 in the liquid phase at temperatures of between 30.degree. and 100.degree. C. on sulfonated, strongly acidic, macroporous organic ion exchange resins. After separation of the unreacted hydrocarbons, the reaction mixture is distilled under pressure; the methanol-containing distillate formed during the distillation is recycled into the zone of the reaction between methanol and isobutene; and pure methyl tert.-butyl ether is withdrawn from the sump of the distillation column.