Process for producing acrolein and acrylic acid
AssigneeMitsubishi Petrochemical Co., Ltd.
InventorsKoju Kadowaki, Kohei Sarumaru, Takeshi Shibano
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Abstract
Acrolein and acrylic acid are produced by vapor-phase catalytic oxidation of propylene in a multi-tubular, fixed-bed reaction vessel with the use of a composite oxide catalyst represented by the formula Mo.sub.a Bi.sub.b Fe.sub.c A.sub.d B.sub.e C.sub.f D.sub.g Si.sub.h O.sub.x, wherein A, B, C, and D represent components selectable from respective groups of elements, and the subscripts a through h and x are specific numbers of atoms of respective elements and groups of elements. This catalyst is adapted and packed in each reaction tube in a manner such that its activity is controlled to increase from the inlet toward the outlet of the tube.
Claims10
The process for producing acrolein and acrylic acid by vapor-phase catalytic oxidation of propylene with molecular oxygen by using a multi-tubular, fixed-bed reaction vessel, comprising:
- (a) contacting propylene with a composite oxide catalyst represented by the formula
- Mo.sub.a Bi.sub.b Fe.sub.c A.sub.d B.sub.e C.sub.f D.sub.g Si.sub.h O.sub.x,
- wherein:
- A is at least one element selected from the group consisting of Co, Ni, and Mg;
- B is at least one element selected from the group consisting of P, B, and As;
- C is at least one element selected from the group consisting of Li, Na, and Mn;
- D is at least one element selected from the group consisting of K, Rb, Cs, and Tl;
- a, b, c, h, and x are the numbers of atoms of their respective elements;
- and d, e, f, and g are the total numbers of atoms of their respective element groups, b being 0.4 to 7, c being 0.1 to 4, d being 2 to 10, e being 0 to 2, f being 0 to 2, g being 0 to 2, and h being 0 to 60, and x being a number satisfying the valences of the elements other than the oxygen when a is 12;
- and
- (b) wherein in each reaction tube the catalyst is packed in the tube in a plurality of divided sections disposed successively in the tube axial direction to form the catalyst bed, said catalyst being comprised of a plurality of species of said composite oxide, respectively varying in the elemental composition of the component D, the proportion of component D as defined by g or a combination thereof, whereby the catalyst species each contain substantially the same proportion of total catalyst, but have varying activities, and wherein the catalyst species are packed respectively in said sections of the catalyst bed so that the activity of each catalyst species increases from the tube inlet toward the tube outlet.
Dependencies are inferred from the claim text.