Process for producing (meth)acrolein and/or (meth)acrylic acid

A method for producing methacrolein and/or methacrylic acid, which comprises:

• filling a tubular type of fixed bed reactor with a solid oxidation catalyst;
• elevating a temperature of the resultant catalyst layer to a range of 250° C. to 400° C. while passing a gas including oxygen, nitrogen, water vapor and 0 to 0.5% by volume of isobutylene and/or tertiary butanol through said catalyst layer;
• passing a gas including 1 to 3.8% by volume of isobutylene and/or tertiary butanol, 7 to 16% by volume of oxygen and 5 to 50% by volume of water vapor through said catalyst layer at a temperature of 250° C. to 400° C. for a period of one hour or more;
• and thereafter
• passing a raw material gas including 4 to 9% by volume of isobutylene and/or tertiary butanol, 7 to 16% by volume of oxygen and 5 to 50% by volume of water vapor through said catalyst layer at a temperature of 250° C. to 400° C.

A method for producing acrolein and/or acrylic acid, which comprises:

• filling a tubular type of fixed bed reactor with a solid oxidation catalyst;
• elevating a temperature of the resultant catalyst layer to a range of 250° C. to 400° C. while passing a gas including oxygen, nitrogen, water vapor and 0 to 0.5% by volume of propylene through said catalyst layer;
• passing a gas including 1 to 3.8% by volume of propylene, 7 to 16% by volume of oxygen and 5 to 50% by volume of water vapor through said catalyst layer at a temperature of 250° C. to 400° C. for a period of one hour or more;
• and thereafter
• passing a raw material gas including 4 to 9% by volume of propylene, 7 to 16% by volume of oxygen and 5 to 50% by volume of water vapor through said catalyst layer at a temperature of 250° C. to 400° C.