Tetrahydrothiophene is the preferred Odorant in city gas. It is being used widely in market with the success of West-to-East gas Project.

The effect of flotation-agent type, dosage, and air-flotation time and air solution volume on treating result is discussed in detail.

Three-tower continuous distillation process of ethyl acetate from aldehyde condensation and purification by gas-phase oxidation of acetic acid and ethylene were also discussed.