Patent ID: 7109372

Claim:
A method for the production of acrylic acid comprising a step of introducing a mixed gas containing propylene and molecular oxygen into a first reaction zone packed with a complex oxide catalyst having molybdenum and bismuth as essential components and oxidizing propylene and obtaining an acrolein-containing gas, a step of introducing said acrolein-containing gas into a second reaction zone packed with a complex oxide catalyst having molybdenum and vanadium as essential components and obtaining an acrylic acid-containing gas, and a step of introducing said acrylic acid-containing gas into an acrylic acid absorption column and causing it to contact an absorbent water thereby obtaining an acrylic acid-containing solution which comprises the steps of (a) said first reaction zone and said second reaction zone being formed in a single reactor by dividing reaction tubes with at least one perforated tube plate, (b) said mixed gas for introduction into said first reaction zone having a propylene concentration in the range of 7–15 vol. % and a water concentration in the range of 0–10 vol. %, (c) said absorbent water is introduced into said acrylic acid absorption column at a mass flow rate in the range of 0.1–1.5 times the mass flow rate of propylene introduced into said first reaction zone, and (d) said acrylic acid-containing solution obtained in said acrylic acid absorption column having a water concentration in the range of 1–45 wt. %.