Fluorinated polyether grafted TiO₂ magnetic composite material for oil-water separation of crude oil emulsion

Abstract

In order to solve the problem of demulsification of oil-water emulsion, a new type of highly efficient and recyclable magnetic fluorine-containing polyether composite demulsifier (Fe₃O₄@Ti-F) was synthesized. Fe₃O₄@Ti-F was prepared by one-pot method to combine magnetic nanomaterial TiO₂ with Fe₃O₄ and graft fluorinated polyether. The successful synthesis of Fe₃O₄@Ti-F was confirmed by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray diffraction (XPS). The demulsification performance of Fe₃O₄@Ti-F was evaluated by using the self-made crude oil emulsion as the experimental object. The demulsification mechanism of the demulsifier and the influence of external factors such as temperature and pH on the demulsification performance of the demulsifier were discussed, and the amount of TiO₂ in the preparation process was determined. The results show that the demulsification efficiency of 50:50 (v/v %) W/O emulsion can reach 90.83% when the dosage of Fe₃O₄@Ti-F is 600 mg/L, the temperature is 65 °C and the time is 30 min. In the neutral acid environment, the demulsification rate of the demulsifier is above 80%. In addition, Fe₃O₄@Ti-F has been proved to have good magnetic effect. Under the action of external magnetic field, it can be recovered and recycled from the two-phase system for 4 times, and its demulsification efficiency is still above 60%. Fe₃O₄@Ti-F will have broad application prospects in the field of oil-water separation in an energy-saving way.

GRAPHICAL ABSTRACT

Keywords:

• TiO2
• Fe3O4
• fluorinated polyether
• magnetic demulsifier
• mechanism of demulsification

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Natural Science Foundation of Shandong Province for Youth (grant nos. ZR2020QE111), Natural Science Foundation of Heilongjiang (grant nos. LH2022E025) and Postdoctoral Science Foundation of China (grant nos. 2020M681073).