Patent GB-640180-A (GB)
Title: Improvements in or relating to the purification of alcohol
IPC: H01F27/14
Filed: 1947-09-19
Abstract: Fermentation ethyl alcohol, particularly distillery phlegms, is purified by treating it in the liquid phase with hydrogen free from carbon monoxide in the presence of a nickel base catalyst. The treatment is preferably effected at between 30 DEG  and 100 DEG  C. and at a pressure between atmospheric and 50 kg./cm2.  The catalyst is preferably maintained in suspension in the alcohol during the treatment or the impure alcohol may be allowed to flow over the surface of a support having the catalyst distributed therein. Specified catalysts are Raney nickel or nickel deposited on a support such as infusorial earth or silica gel.  Other catalysts having a base of nickel activated with a substance known to promote the catalytic activity of nickel in hydrogenation reactions, e.g. manganese, cobalt, molybdenum, chromium and copper may also be used. In examples, the treatment with hydrogen is carried out in the liquid phase in a stainless steel bomb in the presence of Raney nickel at 15 kg./cm2. and at 55 DEG  to 60 DEG  C.  Comparative examples are given for two alcohols already rectified before the hydrogenation treatment and for two alcohols from distillery phlegms heavily contaminated with impurities, particularly aldehydes and esters, and tests are described which show that the sample with the highest initial concentration of aldehyde has undergone the highest degree of purification, the aldehyde content being reduced to less than 12 per cent of its original value, whereas in each case the acidity and ester content are not appreciably diminished.  The alcohol after the hydrogenation treatment may be submitted to a final rectification and this may be effected in the presence of sodium hydroxide which neutralizes the acidity and saponifies the esters, thus yielding an alcohol of good taste.ALSO:Fermentation ethyl alcohol, particularly distillery phlegms, is purified by treating it in the liquid phase with hydrogen free from carbon monoxide in the presence of a nickel base catalyst. The treatment is preferably effected at between 30 DEG and 100 DEG C and at a pressure between atmospheric and 50 kg/cm2. The catalyst is preferably maintained in suspension in the alcohol during the treatment or the impure alcohol may be allowed to flow over the surface of a support having the catalyst distributed therein.  Specified catalysts are Raney nickel or nickel deposited on a support such as infusorial earth or silica gel. Other catalysts having a base of nickel activated with a substance known to promote the catalytic activity of nickel in hydrogenation reactions, e.g., manganese, cobalt, molybdenum, chromium and copper, may also be used. In examples, the treatment with hydrogen is carried out in the liquid phase in a stainless steel bomb in the presence of Raney nickel at 15 kg/cm2 and at 55 DEG  to 60 DEG C.  Comparative examples are given for two alcohols already rectified before the hydrogenation treatment and for two alcohols from distillery phlegms heavily contaminated with impurities, particularly aldehydes and esters, and tests are described which show that the sample with the highest initial concentration of aldehyde has undergone the highest degree of purification, the aldehyde content being reduced to less than 12 per cent of its original value, whereas in each case the acidity and ester content are not appreciably diminished.  The alcohol after the hydrogenation treatment may be submitted to a final rectification and this may be effected in the presence of sodium hydroxide which neutralizes the acidity and saponifies the esters, thus yielding an alcohol of good taste.