Study on the Preparation of Monochloroacetic Acid from the Photo-chlorination of Acetic Acid

This paper devised a new photo chlorination reactor in laboratory scale -- a gas liquid loop reactor, in which a light is placed. The reactor has advantages of good illumination and perfect sealing property. The effects of different temperature on the chlorination of HAc were researched. The relations between the concentration of HAc, MCA and DCA and time were measured. The results between photo chlorination and catalytic chlorination of acetic acid in the presence of acetic anhydride as catalyst in the loop reactor were compared. It was found that the rate of photo chlorination is nearly equal to that of catalytic chlorination of acetic acid. But the concentration of DCA in the presence of light is higher than that of in the presence of acetic anhydride. In order to inhibit the formation of DCA, acetic anhydride as inhibitor was added during the photo chlorination of acetic acid. It was studied that the influence of different concentration and different addition mode of the inhibitor on the formation of DCA.