Process for producing 2,3,3,3-tetrafluoropropene

A process for producing 2,3,3,3-tetrafluoropropene, the process comprising:

• (1) a first reaction step of reacting hydrogen fluoride with at least one chlorine-containing compound selected from the group consisting of a chloropropane represented by Formula (1):
• CClX2CHClCH2Cl, wherein each X is the same or different and is Cl or F, a chloropropene represented by Formula (2):
• CClY2CCl═CH2, wherein each Y is the same or different and is Cl or F, and a chloropropene represented by Formula (3):
• CZ2═CClCH2Cl, wherein each Z is the same or different and is Cl or F in a gas phase in the absence of a catalyst while heating;
• and
• (2) a second reaction step of reacting a reaction product obtained in the first reaction step with hydrogen fluoride in a gas phase in the presence of a fluorination catalyst while heating,
• wherein the second reaction step uses, as a starting material, CF3CCl═CH2 (HCFO-1233xf) and at least one chlorine-containing compound selected from the group consisting of CF2ClCHClCH2Cl (HCFC-242dc) and CF2ClCCl═CH2 (HCFO-1232xf), and
• wherein the CF3CCl═CH2 (HCFO-1233xf) and the at least one chlorine-containing compound are contained in the reaction product obtained in the first reaction step.