Production process of 1,3-butadiene

A process of producing 1,3-butadiene, the process comprising:

• conducting an oxidative dehydrogenation reaction of a raw material gas with a molecular oxygen-containing gas in the presence of a metal oxide catalyst, thereby obtaining gases comprising 1,3-butadiene, the raw material gas comprising 1-butene and 2-butene and having a proportion of 2-butene to a stun of 1-butene and 2-butene, which is defined as 100% by volume, being not less than 50% by volume;
• cooling the gases;
• and
• separating cooled gases into molecular oxygen and inert gases and other gases comprising 1,3-butadiene by selective absorption to an absorbing solvent,
• wherein a concentration of methyl vinyl ketone in the cooled gases is 0% by volume or more and not more than 0.03% by volume,
• wherein a first pressure in the conducting is not less than 0.1 MPaG and not more than 0.4 MPaG,
• wherein a second pressure in the cooling is not more than the first pressure, and
• wherein a third pressure in the separating is not more than the second pressure.