GB309200A - A process for the manufacture and production of mono- and polyhydric alcohols - Google Patents

Abstract

309,200. Johnson, J. Y., (I. G Farbenindustrie Akt.-Ges.). Sept. 28, 1927. Monohydric, dihydric, and polyhydric alcohols are obtained by the catalytic hydrogenation of the condensation products of aldehydes or ketones or aldehydes and ketones, such as aldol, at atmospheric or higher pressure without the removal of the condensing agent, which, however, may be neutralized if desired. Excess of aldehyde or ketone may be removed from the condensation product before the latter is hydrogenated, or the alcohol produced by hydrogenation of such aldehyde or ketone is recovered from. the hydrogenation product. The catalysts may be metals of the 1st and 8th groups of the periodic system and may be activated by oxides, hydroxides, silicates, phosphates &c. of the same or other elements, preferably in conjunction with a carrier such as kieselguhr or fuller's earth. In the examples crude aldol diluted with alcohol is treated with hydrogen at 50‹ C. and 20-30 atmospheres in presence of a nickel-fuller's earth catalyst containing 20 per cent of nickel ; when the absorption of hydrogen ceases or slackens the temperature may be raised to 80‹ C., the process being continued until the pressure ceases to drop; the solvent and the alcohol produced from the uncondensed acetaldehyde is distilled off, leaving 1-3 butylene glycol. In another example crude aldol diluted with water is hydrogenated with nickel at 60-100‹ C., yielding nbutyl alcohol. In another example the crude aldol diluted with water is hydrogenated with nickel at 60-100‹ C., yielding n-butyl alcohol. In another example the crude aldol produced by condensing n-butyl aldehyde is neutralized with acetic acid and freed from butyl aldehyde bv distillation; it is diluted with water and hydrogenated with nickel on fuller's earth at 70-80‹ C. and 20-30 atmospheres, yielding a-ethyl hexanol. In another example, a mixture of aldol and formaldehyde is treated with N caustic soda at 15-20‹ C., the solution is then adjusted to pH=8-10 and when the aldehyde content has been reduced to half the mixture containing the condensation product is neutralized with acetic acid, diluted with alcohol and hydrogenated with a nickel-fullers' earth catalyst; the water is removed by distillation, yielding a water-soluble syrupy product which after removing deposited sodium acetate, is useful as a softening plasticizing &c. agent. In another example the mixture of racemic hexoses obtained in any known way by condensing formaldehyde with a dilute solution of lime (for instance by allowing to stand for several days at ordinary temperature or for 24 hours at 35‹ C.) is hydrogenated at 25 atmospheres at a temperature gradually rising to 100‹ C. with the aid of a nickel catalyst activated by chromium and deposited on kieselguhr, the reaction being continued until the mixture does not affect Fehling's solution; the product is a pale syrup. In another example a 4 per cent formaldehyde solution is heated with sodium carbonate at 130‹ C. and the condensation product is hydrogenated at 100‹ C. and 25 atmospheres with a nickel catalyst on fuller's earth containing 40 per cent of nickel, the product containing glycol, glycerine, and higher polyhydric alcohols. In another example crude aldol containing 30 per cent of acetaldehyde (obtained by condensing formaldehyde with 2N caustic potash) is mixed with acetic acid to produce a solution which when diluted with water gives pH=7, the acetaldehyde is removed by vacuum distillation and the solution is diluted with alcohol and hydrogenated as in the first example with a catalyst made by precipitating cobalt in kieselguhr by means of soda and a ccbalt salt, so that after reduction by hydrogen at 450‹ C. 40 parts of cobalt are associated with 60 parts of kieselguhr. A mixed catalyst may also be employed containing 27 parts copper, 8 parts nickel, 15 parts chromous oxide and 50 parts kieselguhr. This catalyst is made by precipitating with soda solutions of copper and nickel nitrates upon kieseiguhr, making the product into a paste with ammonium chromate and reducing in hydrogen at 511‹ C. Reference has been directed by the Comptroller to Spefication 17193/13.