Patent ID: 7732639

Claim:
A process for the preparation of acrylic acid by catalytic oxidation of propylene and subsequently of acrolein, comprising recycling of unreacted gases by carrying out a partial oxidation of propane to propylene, in the presence of a catalyst having the structure: Mo 1 V a Sb b Nb c S d O x (Ia) in which: a is 0.006 to 1, inclusive; b is 0.006 to 1, inclusive; c is 0.006 to 1, inclusive; d is 0 to 3.5, inclusive; and x is the quantity of oxygen bound to the other elements and depends on their oxidation states, said partial oxidation being conducted in parallel, at an outlet of the acrylic acid recovery stage, and then, after having undergone a second pass through a column used for acrylic acid recovery, returning a gas rich in propane and propylene, to the propylene oxidation wherein partial oxidation of propane to propylene is implemented at high volume velocities per hour VVH greater than 10,000 h −1 .