| abstract |
[Problem] A device for producing methacrylic acid having excellent continuous operability is provided. [Measurement means] The methacrylic acid production apparatus 100 includes a first reactor 10 for obtaining methacrolein, a second reactor 20 for obtaining methacrylic acid, and methacrolein recovery means 70. , Line LA connecting the outlet 10j of the first reactor 10 and the inlet 20i of the second reactor 20, and the line LB connecting the line LA and the oxygen source, and 2 The line LC connecting the outlet 20j of the reactor 20 and the liquid inlet 70i of the methacrolein recovery means 70, and the gas outlet 70gj and the line of the metacrolein recovery means 70 The line LD connecting the LA is provided, the line LD has the heating means 23a, and the heating means 23a is connected to the line LA from the gas outlet 70gj (Xo) When the length of the line up to 100 is set, it is arranged at least part of the position from the gas outlet 70gj to 30. |