GB400189A - Improvements in or relating to the production of organic acids or esters thereof - Google Patents

Abstract

A catalyst for the production of organic acids or their esters from aliphatic alcohols, esters or ethers and carbon monoxide is made by absorbing aqueous chromic acid in pumice or other support, drying at 125 DEG C., and admixing with an adsorbent oxide such as silica gel. Other catalysts mentioned contain molybdic, tungstic, or uranic acid, and instead of silica gel another adsorbent oxide such as alumina gel or active charcoal may be used. The catalytic apparatus, which may be operated at 700 atmospheres pressure, may be made of or lined with glass or may be made of steels containing a high proportion of molybdenum, cobalt, tungsten, chromium, manganese or nickel, or may be internally coated with chromium or silver. Specifications 254,819, [Class 1 (i), Chemical processes &c.], and 283,989, [Class 2 (iii), Dyes &c.], are referred to.ALSO:Aliphatic acids or their esters are produced by passing a mixture of the vapour of an alcohol, ether, or ester and carbon monoxide over a catalyst comprising free chromic, molybdic, tungstic or uranic acid, that is to say the true acids such as H2CrO4 and not the corresponding oxides. These acids may be mixed with an adsorbent oxide such as silica gel or alumina gel or active charcoal. Instead of an alcohol such as methanol, substances or mixtures which form alcohols may be used. Higher alcohols such as hexyl and cetyl alcohols may be employed, in which case if the alcohol is insoluble in water and it is desired to have water present, the alcohol and water may be introduced into the carbon monoxide as vapour or spray. In examples (1) a mixture of 95 per cent carbon monoxide and 5 per cent methanol is passed at 250 DEG C. and 700 atmospheres pressure over a chromic acid catalyst made by absorbing aqueous chromic acid in pumice or other support, drying at 125 DEG C. and admixing with an adsorbent oxide such as silica gel; (2) the same mixture is passed at 350 DEG C. and 700 atmospheres pressure over a tungstic acid catalyst. The catalytic apparatus may be made of or lined with glass or may be made of steels containing a high proportion of molybdenum, cobalt, tungsten, chromium, manganese or nickel, or may be internally coated with chromium or silver. Specifications 254,819 and 283,989, [both in Class 2 (iii), Dyes &c.], are referred to.