Objective Achieving efficient rapid demulsification of water-in-oil emulsion constructed of oil with high viscosity was realized.Methods The g-C3 N4 was prepared from melamine by thermal polymerization method.The composite filter cake was prepared by mixing super-hydrophilic g-C3N4 with diatomite,and the high viscosity water-in-oil emulsion was quickly demulsified by pumping and filtering.Results The filter cake containing 1.5 wt％g-C3N4 with 0.5 cm thickness can realize completely demulsified,which the emulsion with water content less 6 wt％and droplet size larger than 2.32 μm.The demulsification rate of 20 kPa vacuum degree can reach 3.57 L/min,the demulsification efficiency is 97.36％,and the oil recovery rate is above 99.72％.Thickening the filter cake can be used for demulsification of emulsion with higher water content.Such attractive demulsification effect is caused by the simultaneous action of strong affinity of g-C3N4 to water and the crushing effect by micropores of diatomite.Conclusion The g-C3 N4/diatomite composite filter cake can be effectively used for efficient rapid demulsification of water-in-oil emulsion with promising application prospect.
维普
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