Patent GB-827541-A (GB)
Title: Purification of methylisobutylketone
Filed: 1956-10-09
Abstract: <PICT:0827541/III/1> Methylisobutyl ketone prepared by the hydrogenation of mesityl oxide is purified by distilling the impure ketone to take off as overhead product the methyl isobutyl ketone and low-boiling impurities and leave behind high-boiling impurities, extracting impurities from this overhead product with water, and then distilling the overhead product to obtain purified methyl isobutyl ketone.  In the procedure described with reference to the drawing impure methyl isobutyl ketone is fed through line 11 to column 12 provided with a reboiler 13.  The column may be operated at a head temperature of above about 104 DEG  C. at atmospheric pressure but higher or lower pressures with their appropriate temperatures may be used.  The overhead vapours pass to condenser 16 where they are liquefied, the liquid flowing through line 17 into a washer and phase separator 18 into which a stream of water is passed through line 19. The water is intimately contacted with the ketone and is withdrawn through line 21 while a portion of the extracted ketone is returned as reflux to column 12, suitable reflux ratios being between 5 to 1 and 10 to 1.  The remainder of the extracted ketone is passed to column 24 provided with a reboiler 25.  At atmospheric pressure column 24 may be operated at a head temperature of between 93 DEG and 112 DEG  C. and a base temperature between 115 DEG  and 116 DEG C. to distil overhead materials boiling below the boiling-point of methylisobutyl ketone together with a considerable proportion of the ketone and these vapours are liquefied in condenser 27, the resulting liquid being passed to a washer and phase separator 29 into which water is admitted through line 31.  The washed liquid is returned as reflux through line 33 to column 24.  If desired, vessel 29 may be omitted in which case a portion of liquid from condenser 27 is returned as reflux to column 24, the remainder of the liquid being recycled to column 12 through feed line 11.  The purified ketone is withdrawn through conduit 34, condenser 35 and outlet 37, and any high-boiling compounds present are withdrawn through line 36 and recycled to column 12.  An example of this type of procedure is given, the impure ketone used containing as impurities small amounts of hexylene glycol, acetone, isopropyl alcohol, water, and mesityl oxide and an appreciable amount of methyl isobutyl carbinol.  The first column is a 24 plate column operated at a head temperature of 111 DEG  to 114 DEG  C. and a base temperature of 122 DEG  to 127 DEG C. and the second column is a 42 plate column and is operated at a head temperature and pressure of 93 DEG  to 116 DEG  C. and 2 to 3 p.s.i.g., and a base temperature and pressure of 121 DEG  to 123 DEG C. and 4 to 6 p.s.i.g.ALSO:Methylisobutyl ketone prepared by the hydrogenation of mesityl oxide is purified by distilling the impure ketone to take off as overhead product the methylisobutyl ketone and low boiling impurities and leave behind high boiling impurities, extracting impurities from this overhead product with water, and then distilling the overhead product to obtain purified methylisobutyl ketone.  In the procedure described <PICT:0827541/IV (b)/1> with reference to the drawing impure methylisobutyl ketone is fed through line 11 to column 12 provided with a reboiler 13.  The column may be operated at a head temperature of above about 104 DEG  C. at atmospheric pressure but higher or lower pressures with their appropriate temperatures may be used.  The overhead vapours pass to condenser 16 where they are liquefied, the liquid flowing through line 17 into a washer and phase separator 18 into which a stream of water is passed through line 19.  The water is intimately contacted with the ketone and is withdrawn through line 21 while a portion of the extracted ketone is returned as reflux to column 12, suitable reflux ratios being between 5 to 1 and 10 to 1.  The remainder of the extracted ketone is passed to column 24 provided with a reboiler 25. At atmospheric pressure column 24 may be operated at a head temperature of between 93 DEG  and 112 DEG  C. and a base temperature between 115 DEG  and 116 DEG  C. to distil overhead materials boiling below the boiling point of methylisobutyl ketone together with a considerable proportion of the ketone and these vapours pass to condenser 27 where they are liquefied, the resulting liquid being passed to a washer and phase separator 29 into which water is admitted through line 31.  The washed liquid is returned as reflux through line 33 to column 24.  If desired vessel 29 may be omitted in which case a portion of liquid from condenser 27 is returned as reflux to column 24, the remainder of the liquid being recycled to column 12 through feed line 11.  The purified ketone is withdrawn through conduit 34, condenser 35 and outlet 37, and any high boiling compounds present are withdrawn p  through line 36 and recycled to column 12.  An example of this type of procedure is given, the impure ketone used containing as impurities small amounts of hexylene glycol, acetone, isopropyl alcohol, water, mesityl oxide and an appreciable amount of methyl isobutyl carbinol.  The first column is a 24 plate column operated at a head temperature of 111 DEG  to 114 DEG  C. and a base temperature of 122 DEG  to 127 DEG  C. and the second column is a 42-plate column and is operated at a head temperature and pressure of 93 DEG  to 116 DEG  C. and 2 to 3 p.s.i.g. and a base temperature and pressure of 121 DEG  to 123 DEG C. and 4 to 6 p.s.i.g.