Patent GB-656405-A (GB)
Title: Manufacture of methyl-isobutyl ketone
IPC: C07C45/73
Filed: 1947-12-09
Abstract: Methyl isobutyl ketone is obtained by contacting acetone vapours and hydrogen at a temperature between 180 DEG  and 300 DEG  C. with a contact material comprising initially a mixture of a copper compound which is reducible to metallic copper by the mixture of said reactants at reaction temperatures, with magnesium oxide and/or magnesium hydroxide.  The contact material may be heated in a current of hydrogen before use.  Copper compounds specified are cupric oxide, cuprous oxide and the hydroxides of copper.  Cupric hydroxide is preferred and the contact material may be prepared by mixing an aqueous solution of a water-soluble copper salt such as the formate, nitrate or acetate with an excess of magnesium oxide or hydroxide. The magnesium oxide may be prepared from precipitated hydroxide or it may be calcined magnesium carbonate either in the form of fine powder or of granules.  The initial mixture may also be prepared by mixing the magnesium oxide and/or hydroxide with a suitable copper compound such as the oxide or hydroxide of copper in the dry state.  It is preferred to give the contact material a preliminary treatment by heating in a current of hydrogen.  This treatment may be effected at between 250 DEG  and 500 DEG  C. and may be carried out in two stages, first at 250 DEG  to 300 DEG  C. and then at 400 DEG  to 500 DEG  C.  Before heating in a current of hydrogen the mixture may be calcined by heating to a temperature between 300 DEG  and 500 DEG  C. The reaction of the acetone and hydrogen is preferably effected at 200 DEG  to 250 DEG  C. and the use of about two moles of acetone to about one mole of hydrogen is preferred.  The process may be effected at atmospheric, sub-atmospheric or superatmospheric pressure and the mixture may be conducted over the solid contact material or the latter may be dispersed in a liquid inert medium, e.g. high boiling hydrocarbons such as kerosene or paraffin oil, vegetable oils such as cotton seed oil, liquid silicones and high boiling polyglycol ethers. The catalyst may be revivified after use by subjecting it to a heat treatment at between 250 DEG  and 500 DEG  C. in the presence of molecular oxygen containing gases such as air and then reducing by means of hydrogen, preferably in two stages at about 250 DEG  C. and between 400 DEG  and 500 DEG  C. respectively.  In examples: (1) an aqueous solution of cupric nitrate trihydrate is added to an aqueous suspension of magnesium oxide and the resulting precipitate filtered, washed with water and dried below 100 DEG  C.  After sieving, the dried mixture of copper hydroxide and magnesium hydroxide obtained is heated to 300 DEG  C. in a mild steel tube and a mixture of acetone and hydrogen passed over it.  A mixture containing methyl isobutyl ketone with smaller amounts of mesityl oxide and isopropyl alcohol is obtained; (2) the catalyst mixture prepared as in (1) is first treated with hydrogen in two stages at 250 DEG  and 400 DEG  C. and acetone and hydrogen are then fed over the mixture at 250 DEG  C. yielding a mixture containing methyl isobutyl ketone with smaller amounts of di-isobutyl ketone and isopropyl alcohol; (3) the catalyst is prepared by mixing calcined magnesite with aqueous copper formate and after drying the mixture is heated in a current of air at 400 DEG C.  After reacting the acetone and hydrogen as in (1) a mixture containing the products of (2) as well as a small amount of methyl isobutyl carbinol is obtained; (4) as in (3) except that the catalyst mixture is first treated with hydrogen at 500 DEG  C.; (5) as in (4) the catalyst being regenerated after use by passing air over it at 500 DEG  C. and then heating in hydrogen at 500 DEG  C.  Comparative examples are given in which acetone and hydrogen are passed over (1): a mixture of elemental copper and aluminium oxide under similar conditions to yield a mixture containing methyl isobutyl ketone in a lower yield together with diisobutyl ketone, methyl isobutyl carbinol and liquid hydrocarbons, and (2): over a nickel-magnesia catalyst. Specifications 326,812, [Class 2 (iii)], 362,204, 400,384 and 410,148 are referred to.ALSO:In the production of methyl isobutyl ketone by contacting acetone vapours with hydrogen at 180 DEG  to 200 DEG  C. (see Group IV (b)), the contact material comprises a mixture of a copper compound which is reducible to metallic copper by the mixture of reactants at the reaction temperature with magnesium oxide and/or magnesium hydroxide.  Specified copper compounds are cupric oxide, cuprous oxide and the hydroxides of copper.  The catalyst mixture may be prepared by mixing an aqueous solution of a water-soluble copper salt, e.g. the formate, nitrate or acetate with an excess of magnesium oxide or hydroxide.  The magnesium oxide may be prepared from precipitated hydroxide or it may be calcined magnesium carbonate.  The contact mixture may be heated in a current of hydrogen before use, e.g. at 250 DEG  to 500 DEG  C. and prior to this treatment the mixture may be calcined by heating to 300-500 DEG C.  After use the catalyst can be revivified by heat treatment in the presence of molecular-oxygen containing gases such as air and then reducing with hydrogen as above.  The heat treatment may be carried out in the presence of oxygen at 250-500 DEG  C.  In examples, the contact material is prepared by (1) adding an aqueous solution of cupric nitrate trihydrate to an aqueous suspension of magnesium oxide, the precipitate formed being then dried at below 100 DEG  C.; (2) as in (1) followed by reduction in hydrogen at 250 DEG  and 400 DEG  C.; (3) mixing calcined magnesite with aqueous copper formate, drying, and then heating in air at 400 DEG  C.; (4) revivifying the catalyst used in (3) by passing air over the bed at 500 DEG  C. and then passing hydrogen over at 500 DEG  C.  Comparative examples indicate the results obtained using a catalyst containing elemental copper and aluminium oxide and a nickel-magnesia catalyst.