| 摘要 |
<p>1,198,930. Acrolein; methacrolein; acrylic acid; methacrylic acid. MONTECATINI EDISON S.p.A. 13 May, 1968 [16 May, 1967], No. 22503/68. Heading C2C. [Also in Division B1] Acrolein and/or acrylic acid, or methacrolein and/or methacrylic acid, is prepared by the vapour phase oxidation of propylene and/or acrolein, or of isobutylene and/or methacrolein, with oxygen in the presence of a catalyst comprising a mono-phase system based on molybdenum trioxide the crystal lattice of which has been altered by inclusion of atoms of a substituted metal Ms in an amount such that the atomic ratio of Ms to Mo is 1 to 9, the metal Ms being manganese, cobalt or nickel. The catalyst, which may be in the form either of a fixed bed or of a fluidized bed, optionally may include a small quantity of a salt or oxide of an alkali metal and/or may be supported on a carrier material, for example silica, carborundum or pumice stone. The oxidation is carried out either at atmospheric pressure or at elevated pressure, for example at from 2 to 10 atmospheres, at a temperature of from 350‹ to 500‹ C., preferably of from 380‹ to 450‹ C., and with a contact time of from 0À05 to 5 seconds, preferably of from 0.3 to 1 second, the molar ratio of propylene and/or acrolein, or of isobutylene and/or methacrolein, to oxygen preferably being between 0À75 to 1 and 2 to 1, for example 1 to 1. The oxygen may be supplied in the form of air, pure oxygen or a mixture of air and oxygen. The oxidation may be carried out in the presence of a halogencontaining organic compound, for example allyl chloride or allyl bromide, and/or in the presence of an inert gaseous diluent, for example steam, nitrogen, carbon dioxide, a saturated hydrocarbon such as for example propane, or the oxidation reaction products after removal therefrom of product aldehyde and/or product acid; product aldehyde may be recycled in order to be oxidized further to the corresponding acid.</p> |
