METHOD OF USING PARTIAL GAS-PHASE OXIDATION OF ACROLEIN INTO ACRYLIC ACID OR METHACROLEIN INTO METHACRYLIC ACID ON HETEROGENEOUS CATALYST Russian patent published in 2013 - IPC C07C51/25 C07C51/235 C07C57/55 

FIELD: chemistry.

SUBSTANCE: invention relates to an improved method of using gas-phase partial oxidation on a heterogeneous catalyst of acrolein into acrylic acid and methacrolein into methacrylic acid on a fixed catalyst bed lying in a shell-and-tube reactor in reaction tubes of a vertical bundle of reaction tubes enclosed in the reactor shell, when both ends of each of the reaction tubes are open and each reaction tube, through its top end, tightly enters a through-hole which is tightly built into the top part of the reactor shell of an upper tube sheet, and through its bottom end, tightly enters a through hole which is tightly built into the bottom part of the reactor shell of a lower tube sheet, wherein the outer surface of the reaction tubes, the upper and lower tube sheets, as well as the reactor shell together bound the space which surrounds the reaction tubes, wherein each of the two tube sheets is closed by a reactor cover having at least one hole, when in order to put into operation, a starting gaseous reaction mixture containing ≥3 vol. % acrolein or methacrolein and also molecular oxygen is fed into the reaction tubes of the shell-and-tube reactor through at least one hole, denoted hereafter as E, in one of the two reactor covers, and the gaseous product mixture containing acrylic acid or methacrylic acid, which is formed as a result of gas-phase partial oxidation of acrolein or methacrolein into acrylic acid or methacrylic acid by passing through a fixed catalyst bed lying in the reaction tubes, is removed through at least one hole in the other reactor cover, wherein at least one liquid heat carrier is fed from the side of the shell to the reaction tubes of the shell-and-tube reactor, the movement of the liquid heat carrier being such that each of the surfaces of both tube shells facing each other is covered by the liquid heat carrier, and wherein at least one liquid heat carrier enters the space surrounding the reaction tubes with temperature T_w ⁱⁿ and comes out of said space with temperature T_w ^out. At the moment of use, the starting gaseous reaction mixture containing ≥3 vol. % acrolein or methacrolein is fed through at least one hole in the reactor cover, wherein temperature T_w ⁱⁿ of at least one liquid carrier which is in contact with the tube sheet closed by the reactor cover having at least one hole E, denoted hereinafter as reactor sheet E, is not lower than 290°C; the starting gaseous reaction mixture coming through at least one hole E has temperature ≤285°C and temperature of the surface of the reactor sheet E facing the reactor cover having at least one hole E, denoted hereinafter as the surface of reactor sheet E, is ≤285°C.

EFFECT: improved method.

16 cl, 4 dwg, 6 tbl, 3 ex