| abstract |
A process for the production of alpha-beta unsaturated carboxylic acid with high yield at low temperature and atmospheric pressure, includes two stages for catalytic vapor-phase oxidation of olefins with molecular oxygen. In a first stage, olefins are oxidized using catalyst A having a composition according to the formula n Mo a Pd b Bi c Fe d X 1 e X 2 f X 3 g O z , n wherein n X 1 =one or more of Co, Ni, V, Pt, Rh; X 2 =one or more of Al, Ga, Ge, Mn, Nb, Zn, Ag, P, Si, W; X 3 =at least one or more of K, Mg, Rb, Ca, Sr, Ba, Na; and O=oxygen; to produce a first stage product containing alpha-beta unsaturated aldehydes n In a second stage, alpha-beta unsaturated aldehydes in the first stage product are oxidized using catalyst B having a composition according to the formula n Mo a V b Al c X d Y e O z n wherein n X=W or Mn or both; Y=at least one or more of Pd, Sb, Ca, P, Ga, Ge, Si, Mg, Nb, K; and O is oxygen which satisfies the valences of the other elements; to produce mainly alpha-beta unsaturated carboxylic acid. n A portion of the oxygen is introduced into the reaction stream between the first and second stages or in multistages. More particularly, the invention relates to a two stage process for catalytic oxidation of propylene or iso-butylene to yield acrylic acid or methacrylic acid. |