Gas phase oxidation of propylene to acrylic acid using ring-shaped multi-metal oxide catalyst of specified geometry to maximize selectivity and space-time yield

    公开(公告)号:DE19927624A1

    公开(公告)日:2000-12-21

    申请号:DE19927624

    申请日:1999-06-17

    Applicant: BASF AG

    Abstract: Gas phase oxidation of propylene into acrylic acid in which the mixture of reaction gas is oxidized on a first fixed-bed catalyst and the mixture of product gas which contain acrolein oxidized on a second fixed-bed catalyst. The catalyst shaped bodies comprise an annular geometry in both reaction steps. Gas-phase oxidation of propylene in a one-stage reaction to acrolein and/or acrylic acid or in a two-stage reaction to acrylic acid is such that (i) the initial charge in both cases is \- 160 Nl propylene/l catalyst hour; (ii) the charge to the 2nd stage (if used) includes \- 140 NL acrolein/l catalyst hour ; and (iii) the catalyst or catalysts is/are of ring form with an outer diameter 2-11 mm, length 2-11 mm and a wall-thickness 1-5 mm. The process comprises (A) feeding a mixture of propylene, molecular oxygen and an inert gas with molar ratio O2 : C3H6 \- 1 at high temperature over a solid bed catalyst with characteristics (i) and (iii) above and comprising a multi-metal oxide containing Mo and/or W together with Bi, Te, Sb, Sn and/or Cu such that the propylene conversion and the combined selectivity for acrolein and the acrylic acid by-product are both \- 90 mol.%; and optionally (B) cooling the acrolein-containing gas product and optionally adding molecular O2 and/or inert gas prior to passing it at high temperature and with molar ratio O2 : acrolein \- 0.5 over a Mo- and V-containing multi-metal oxide solid bed catalyst such that the acrolein conversion is \- 90 mol.% and the combined two-stage acrylic acid selectivity (based on propylene conversion) is \- 80 mol.%.

    Metallic reactor tube, useful for the production of (meth)acrolein and/or (meth)acrylic acid by catalytic gas-phase oxidation of alkane or alkene etc.

    公开(公告)号:DE19839782A1

    公开(公告)日:2000-03-02

    申请号:DE19839782

    申请日:1998-09-01

    Applicant: BASF AG

    Abstract: A metallic reactor tube with a catalytic coating of multi-metal oxide material containing molybdenum and bismuth, directly applied to the tube. Independent claims are also included for (a) a pipe bundle reactor with reactor tubes as defined; (b) a process for the production of coated reactor tubes or pipe bundle reactors, comprising (1) preparation of solutions, emulsions and/or dispersions of the elements and/or their compounds required for the catalyst and/or its precursor, (2) possible addition of coupling agents, binders, viscosity regulators and/or pH regulators, (3) application to the tube(s), preferably on the inside, preferably by spraying or dip-coating and (4) drying and possibly sintering or calcining by heating the coated tube at 20-1500 (preferably 200-400) deg C, optionally in presence of inert or reactive gas; (c) a process for the production of (meth)acrolein and/or (meth)acrylic acid by the catalytic gas-phase oxidation of 1-6C alkanes, 2-6C alkenes, 1-6C alkanols and/or alkanals and/or precursors thereof, using a reactor tube or pipe bundle reactor as above.

Patent Agency Ranking