Abstract: Water can be changed from liquid to saturated steam by heating method, which results in the destroy of hydrogen bonds among H2O molecules and the exposure of hydrogen atomic nuclei to function as the protons for attacking metal ions in non-hydrated phospholipids. The non-hydrated phospholipids can be removed from crude oil through the separation between phosphatidic acids and divalent metal ions. The optimal removal process of non-hydrated phospholipids was based on hydration degumming of crude oil for the removal of hydrated phospholipids, heating of hydrated degummed oil to 110 ℃, stirring at 90 r/min, introduction of 2% (on the basis of oil amount) saturated steam pressure at 0.14 MPa allowed to proceed for 50 min. Under the optimal conditions, the phosphorus content in degummed oil was 17.9 mg/kg. This method can provide a theoretical basis for industrial production.

Key words: soybean oil, steam degumming, oxygen atom, non-hydrated phospholipids, phosphorus content