Patent ID: 7326810

Claim:
In the reaction of catalytic gas phase oxidation induced by the supply of at least a raw material to be oxidized and a molecular oxygen-containing gas to a reactor for the reaction of catalytic gas phase oxidation, a method for starting up the reactor characterized by (i) during starting up the reactor causing said raw material and said molecular oxygen-containing gas to have a range in which the concentration of said raw material is less than the concentration of the lower explosion limit of said raw material and the concentration of oxygen is not less than the limiting oxygen concentration corresponding to the lowest concentration of oxygen forming an explosion range and passing across a border line where the concentration of oxygen is the limiting oxygen concentration, but excluding the concentration of said raw material of 0 vol. %, said raw material being selected from the group consisting of propylene, propane, acrolein, isobutylene, methacrolein, xylene, naphthalene and, benzene and (ii) then for reaching steady state causing a range in which the concentration of said raw material is not less than the concentration of the lower explosion limit of said raw material and the concentration of oxygen is less than the limiting oxygen concentration, thereby reaching the steady state.