Producing method of methyl acrylic acid

Application Number: 00106988
Application Date: 2000.04.26
Publication Number: 1273232
Publication Date: 2000.11.15
Priority Information: 1999/4/27 JP 119170/99; 1999/5/6 JP 126034/99
International: C07C51/235;C07C57/04;C07C57/055
Applicant(s) Name: Nippon Shokubai Co., Ltd.
Inventor(s) Name: Onodera Hideo;Kimura Naomasa;Shiraishi Eiichi
Patent Agency Code: 72001
Patent Agent: liu yuanjin
Abstract A process for vapor phase catalytic oxidation of methacrolein to produce methacrylic acid at high yield and with stability over a prolonged period is provided. The process is characterized, in the occasion of producing methacrylic acid by vapor phase catalytic oxidation of methacrolein using a fixed bed shell-and-tube reactor, in that (1) the catalyst layer in each reaction tube is divided into at least two layers in the axial direction of the tube to provide plural reaction zones, and (2) each of the reaction zones is filled with the catalyst in such a manner that the amount of the catalytically active component per unit volume of the reaction tube decreases from the gas inlet portion toward the gas outlet portion.