GB871278A - A process for the production of carboxylic acids - Google Patents

Abstract

Carboxylic acids are prepared from a monoolefinically unsaturated compound with three or more carbon atoms per molecule, carbon monoxide, and water using an inorganic strong or 'Lewis' acid as catalyst in a process in which liquid catalyst and reactants are continuously supplied to a reaction zone, the amounts of water and mono-olefine being in a molar ratio of more than 1:1, the liquid reaction mixture is kept homogeneous and of constant composition, and the reaction mixture is continuously withdrawn. The reaction zone is stirred or agitated, and a water to olefine ratio of up to 30 : 1, preferably from 2:1 to 6:1 is used, at a temperature of between -10 and 150 DEG C., preferably 40-100 DEG C. and a carbon monoxide pressure of above 20 atoms preferably 50 to 150 atmos. Catalysts include phosphoric, sulphuric acids, hydrated boron trifluoride and its complexes with such acids. Monoolefine compounds specified are propylene and propylene tetramer, butylene-1 and -2, mono- and di-isobutylene, branched and unbranched pentenes, hexenes, heptenes, octenes, nonenes, decenes and higher alkenes, cyclopentene and hexene, and technical mixtures from the thermal vapour phase steam cracking of paraffin wax and an example describes the use of a mixture of 76% alkenes, with 8-10 carbon atoms per molecule, 17% of saturated hydrocarbons with a phosphoric acid-boron trifluoride catalyst. The reactor effluent is separated into two layers by the addition of an organic diluent, the catalyst phase recycled, and the organic phase containing the acid treated by water-washing, conversion to salts e.g. sodium, extraction with gasoline, acidification and fractional distillation. Specifications 743,597 and 798,065 are referred to.