| 摘要 |
PROBLEM TO BE SOLVED: To obtain methacrolein and methacrylic acid in high yield by using a catalyst stably for a long time while preventing its deterioration as well as suppressing heat storage at a hot-spot during reaction. SOLUTION: The objective methacrolein and methacrylic acid are obtained by vapor phase catalytic of isobutylene by molecular oxygen or a molecular oxygen-contg. gas by use of stationary bed multitubular reactor in the presence of a multiple oxide catalyst of the formula Moa Wb Bic Fed Ae Bf Cg Dh Ei Ox (Mo is molebdenum; W is tungsten; Bi is bismuth; Fe is iron; A is nickel or cobalt; B is alkali metal or thallium; C is alkaliune earth metal; D is phosphorus, tellurium, etc.; E is silicon, aluminum, etc.; O is oxygen). It is preferable that the catalyst to be used for the reaction is of ring shape 10mm in outer diameter, with its length 0.5-2 times the outer diameter and the inner diameter of the penetrated hole in the longer direction 0.1-0.7 times the outer diameter. |
