GB807581A - Production of alkynols and alkynediols - Google Patents

Abstract

Alkynols (including alkyndiols) are made by reacting aldehydes or ketones with acetylene (see Group IV (b)) in the presence of a catalyst made by depositing copper oxide on a siliceous carrier which is then heated to a temperature of 400 DEG to 800 DEG C., by which a surface layer of copper silicate is formed. Preferably a little bismuth oxide is present with the copper oxide. The metal silicate prevents the formation of cuprene. Kaolin, silica gel, or fuller's earth may be used as the carrier, but preferably kaolin is mixed with an organic binder, formed into shapes and roasted at 800 DEG to 850 DEG C. to burn out the binder, and finally heated at 1000 DEG to 1200 DEG C. to impart a mullite-like structure. Binders specified are, polyacrylic acid, alginic or pectic acid, polyvinyl methyl ether or methyl cellulose. In examples, the calcined carrier is impregnated with a solution containing copper nitrate or nitrite, bismuth nitrate and dilute nitric acid. The pulp is extruded, and the shaped pieces dried and finally heated at 400 DEG to 800 DEG C. for 5 to 34 hours. The bismuth compound may be replaced by compounds of Au, Hg, Pb, Se, Ce, or of halogens. U.S.A. Specifications 2,232,867 and 2,300,969 are referred to.ALSO:Alkynols (including alkyndiols) are made by reacting aldehydes or ketones with acetylene in the presence of a catalyst made by depositing copper oxide on a siliceous carrier which is then heated to a temperature of 400 DEG to 800 DEG C., by which a surface coating of copper silicate is formed, thus preventing the formation of cuprene. Preferably, there is also present a small amount of an oxide of Bi, Au, Hg, Pb, Se or Ce. Kaolin, silica gel, or fuller's earth are used as carrier, but preferably kaolin is mixed with a polymeric organic binder, the mixture formed into shapes, dried, calcined and then impregnated with solutions of the metal salts and re-ignited (see Group III). In examples, a long tubular reactor column packed with the catalyst is first flushed with nitrogen, and then heated to 90 DEG C., while a 6 per cent formaldehyde solution trickles downwards through the column. Acetylene is bled into the nitrogen feed increasing to a concentration of 70 per cent acetylene, and also the temperature is raised to 120 DEG C. The concentration of formaldehyde is also raised to 18.5 per cent. The gases produced are condensed, surplus gases recycled, and water removed from the condensate, which is then submitted to azeotropic distillation. In a 600 hour operation, 80 per cent of the formaldehyde is converted to alkyne diol. U.S.A. Specifications 2,232,867, 2,300,969 and 2,527,358 are referred to.