The invention concerns a process for oxidative dehydrogenation of ethane. In the process an ethane comprising stream is fed to a distillation column to remove propane. The purified ethane stream is subjected to oxidative dehydrogenation using a catalyst comprising Mo/V/Sb, or Mo/V/Nb and Te or Sb in the orthorhombic M1 crystalline phase. The reactor effluent comprises ethylene. The effluent is washed with water to remove acetic acid. The acetic acid is recovered from the aqueous stream by means of solvent extraction.