Patent GB-710447-A (GB)
Title: Improvements in or relating to methods and apparatus for the catalytic hydrogenationof furfuraldehyde
Filed: 1952-01-21
Abstract: <PICT:0710447/IV (b)/1> Furfuryl alcohol is prepared by hydrogenating furfuraldehyde characterised in that furfuraldehyde is stirred for at least 2 hours in the presence of hydrogen under a pressure ranging from 2 to 20 kg./cm.2 and at a temperature ranging from 80 DEG  to 130 DEG  C., with finely-divided Raney nickel powder which has previously been treated to reduce the activity of the nickel powder, either by heating for at least half an hour at a temperature of about 100 DEG  C. with furfuraldehyde or by using said powder in another hydrogenation process, e.g. in the hydrogenation of vegetable oils or animal fats.  The nickel powder remaining after the hydrogenation of furfuraldehyde to furfuryl alcohol may be used again after it has been stirred for about 12 hours in a 20 per cent aqueous alkali hydroxide solution at a temperature ranging from 100 DEG  to 120 DEG C.  A number of examples are given.  A suitable apparatus for carrying out the above process is shown in the Figure and consists of one or more vertical units 1, 2, 3 and 4 to which hydrogen is supplied through pipes 6.  Each unit contains a hydrogenation chamber 7 heated by a steam jacket 9, the steam being supplied through pipe 11, a loading pipe 21 for the catalyst and an outlet pipe 12 which connects from the bottom of each chamber to the middle portion of the next unit.  The pipe 12 from the last unit connects with an outlet pipe 24 fitted with an optical device to determine the refractive index of the reaction product in order to control reaction rates. The tank 23 contains the furfuraldehyde and the furfuraldehyde is fed into the first unit through pipe 12.  Disc stirrers 13 are used to sweep the chambers, and are actuated by means of the rods 14 which carry magnetic cores 16 and the electromagnets 18.  Each electromagnet may consist of three piled-up coils, the iron core 16 being twice the height of each coil, and the disc is moved upwards by passing current through the lowermost coil.  The current is then fed to the middle coil and almost immediately interrupted in the lowermost coil to allow the core to move upwards still further. The top coil is then brought into action in a similar way to complete the upward movement of the disc.  The procedure is then reversed to force the disc downwards.  Furfuraldehyde is purified by contact with Raney nickel powder for at least half an hour at a temperature of about 100 DEG  C.ALSO:A catalytic hydrogenation apparatus, which may be used to hydrogenate furfuraldehyde to furfuryl alcohol, consists of one or more units 1, 2, 3 and 4 to which hydrogen is supplied through pipes 6.  Each unit contains a hydrogenation chamber 7 heated by a steam jacket 9, the steam being supplied through pipe 11, a loading pipe 21 for the catalyst and an oulet pipe 12 which connects from the bottom of each chamber to the middle portion of the next unit.  The pipe 12 from the last unit connects with an outlet pipe 24 fitted with an optical device to determine the refractive index of the reaction product in order to control reaction rates.  The tank 23 contains the compound to be hydrogenated and the compound is fed into the first unit through pipe 12.  Disc stirrers 13 are used to sweep the chambers, and are actuated by means of the rods 14 which carry magnetic cores 16 and the electromagnets 18.  Each electromagnet may consist of three piled-up coils, the iron core 16 being twice the height of each coil, and the disc is moved upwards by passing current through the lowermost coil.  The current is then fed to the middle coil and almost immediately interrupted in the lowermost coil to allow the core to move upwards still further.  The <PICT:0710447/III/1> top coil is then brought into action in a similar way to complete the upward movement of the disc.  The procedure is then reversed to force the disc downwards.