| 摘要 |
Catalytic materials for use in the conversion of ethyl alcohol into higher alcohols by treatment with hydrogen comprise an alkaline-earth metal oxide, especially magnesia, activated by the presence of small quantities of one or more oxides of the metals lead, thorium, silver, uranium, tungsten, cadmium, tin, chromium, manganese, zinc, iron, nickel, cobalt, copper, and according to the Provisional Specification alkali metals also. The catalytic mixture may be stabilized by the addition of aluminium hydroxide, stannic acid, silica gel, or wood charcoal; the influence of the latter is stated to persist even after the usual regenerative treatment with oxidizing gases or steam at temperatures of 300-500 DEG C. Pretreatment of the catalysts with moist gases containing oxygen is advantageous. Catalytic mixtures employed according to the examples comprise (1) magnesium oxide, aluminium oxide, and copper oxide; (2) magnesium oxide and copper oxide; (3) magnesium oxide, aluminium oxide, copper oxide, and silver oxide; in each case the magnesium oxide is present in preponderating quantity.ALSO:Higher alcohols, particularly butyl alcohol, are prepared by passing ethyl alcohol vapour together with hydrogen at atmospheric pressure over catalysts comprising an alkaline-earth metal oxide, especially magnesia, activated by the presence of small quantities of one or more oxides of the metals, lead, thorium, silver, uranium, tungsten, cadmium, tin, chromium, manganese, zinc, iron, nickel, cobalt, and copper. The reaction is effected below 400 DEG C., preferably between 200 and 350 DEG C., using one-half to three molecular proportions of hydrogen (a molecule being regarded as H2) per molecular proportion of alcohol. The catalytic mixture may be stabilized by the addition of aluminimum hydroxide, stannic acid, silica gel, or wood charcoal; the influence of the latter is stated to persist even after the usual regenerative treatment with oxidizing gases or steam at temperatures of 300-500 DEG C. Pretreatment of the catalysts with moist gases containing oxygen is advantageous. Any aldehyde formed during the reaction may be recovered and returned, together with unchanged alcohol, to the process. Examples are given of the passage of ethyl alcohol vapour and hydrogen over catalysts consisting of (1) magnesium oxide, aluminium oxide, and copper oxide, (2) magnesium oxide and copper oxide, (3) magnesium oxide, aluminium oxide, copper oxide, and silver oxide; in each case the magnesium oxide is present in preponderating quantity. The products comprise n-butyl, hexyl and octyl alcohols, together with acetaldehyde and some butyric aldehyde and crotonaldehyde. Specifications 326,812 and 336,811, [both in Class 2 (iii), Dyes &c.], are referred to. The Provisional Specification states that the catalyst may also be improved by the addition of limited quantities of oxides or hydroxides of alkali metals. |
