Patent GB-627293-A (GB)
Title: Improvements in and relating to the hydrogenation of furfural
IPC: C07D307/12
Filed: 1946-02-26
Abstract: Furfural is hydrogenated continuously in the liquid phase at a raised pressure in the presence of a foraminate copper or foraminate cobalt catalyst to yield, according to the conditions, furfuryl alcohol, tetrahydrofurfuryl alcohol, 1 : 2- and 1 : 5-pentanediols and pentanols.  Suitable catalysts are obtainable, as described in Specifications 611,987 and 621,749, by alloying cobalt or copper with a metal of greater solubility in acid or alkali, and treating the alloy in granule form with an acid or alkaline solution, according to the alloying metal used. Suitable alloying metals are aluminium, zinc and silicon.  The catalysts may be used in alkalised or unalkalised form and the alkali, if used, may be present in the catalyst or included in the feed; alkalies derived from alkali or alkaline-earth metals or magnesium are suitable.  Specified catalysts are obtained by treating a granulated 55 : 45 copper-aluminium or 30 : 70 cobalt-aluminium alloy with dilute caustic soda at about 100 DEG  C. p  until 20 per cent of the aluminium content has been removed. Examples of the use of the catalysts are given, and Specification 605,922 also is referred to.ALSO:Furfural is hydrogenated continuously in the liquid phase at a raised pressure in the presence of a foraminate copper or foraminate cobalt catalyst to yield, according to the conditions, furfuryl alcohol, tegrahydrofurfuryl alcohol, 1 : 2- and 1 : 5-pentanediols and pentanols.  These products are obtained at successively increasing temperatures, but the temperature necessary in any particular case depends on the nature and age of the catalyst, a higher temperature being required as the catalyst ages.  Suitable catalysts are obtainable as described in Specifications 611,987, [Group III], and 621,749, by alloying cobalt or copper with a metal of greater solubility in acid or alkali, and treating the alloy in granule form with an acid or alkaline solution, according to the alloying metal used.  Suitable alloying metals are aluminium, zinc and silicon.  The catalysts may be used in alkalised or unalkalised form and the alkali, if used, may be present in the catalyst or included in the feed; alkalies derived from alkali or alkaline-earth metals or magnesium are suitable.  Specified catalysts are obtained by treating a granulated 55 : 45 copper-aluminium or 30 : 70 cobalt-aluminium alloy with dilute caustic soda at about 100 DEG C. until 20 per cent of the aluminium content has been removed.  In examples of the use of a foraminate cobalt-aluminium catalyst; (1) furfural at 15 DEG  C. and 250 atm. yields furfuryl alcohol; (2) a mixture of equal parts of furfural and tetrahydrofurfuryl alcohol at 50 DEG  C. and 250 atm. yields substantially pure tetrahydrofurfuryl alcohol.  In examples of the use of a foraminate copper-aluminium catalyst; (3) furfural at 80 DEG  C. and 250 atm. yields furfuryl alcohol; (4) furfural at 120 DEG  C. and 250 atm. yields a mixture of 1 : 2- and 1 : 5-pentanediols while at 150 DEG  C. some pentanols also are obtained. The use of pressures of 50-400 atm. is mentioned, and Specification 605,922 also is referred to.