| 摘要 |
<p>Propylene or isobutylene is converted to acrolein or methacrolein in the presence of MoO3 and MgO, CaO, BaO or SrO the atomic ratio of Mo to the other metal being at least 1 : 1. Also methanol is converted to formaldehyde in the presence of MoO3 and iron oxide. Examples I-V describe the preparation of acrolein from propylene: oxygen: water 2: 1: 3 at 450 DEG C., examples VI-IX describe the preparation of methacrolein from iosbutylene: oxygen: water in the ratio 1.1: 1: 6.3 at 550 DEG C., examples X-XII describe the preparation of formaldehyde from air:methanol 8: 1 at 375 DEG C., example XIII describes the preparation of maleic anhydride from 5% butene in air, Example XIV describes the preparation of phthalic anhydride from oxygen : naphthalene 28: 1 and Example XVI describes the preparation of benzaldehyde from toluene: oxygen: water 2: 1: 6 at 450 DEG C. Specifications 228,771, 237,688, 893,077, 985,009 and U.S.A. Specifications 1,913,405, 2,031,475, 2,625,819 and 2,879,300 are referred to.ALSO:A process for regenerating a metallic oxide catalyst at least part of which is an oxide of Cr, V, Mo or W comprises contacting the catalyst with a vapour containing a compound of the metal corresponding to that contained in the catalyst. The compound selected may be either volatile or water-soluble in which case a solution thereof is used in vapour form. Compounds referred to are oxides, chlorides (and other halides), oxychlorides, ammonium salts of the chlorides, nitrates and sulphates. In examples catalysts containing MoO3 are regenerated using a vapour containing MoO3 or pellets of MoO3 in the path of vapour which makes contact with the catalyst. Other MoO3-containing catalysts are regenerated using MoOCl4 or Mo(CO)6, V2O5-containing catalysts with VOCl3 and CrO3-containing catalysts with vapours containing CrO3. Specifications 228,771, 237,688, 893,077, 985,009 and U.S.A. Specifications 1,913,405, 2,031,475, 2,625,819 and 2,879,300 are referred to.</p> |
