Method of using ultrasonic wave to change wet alga cell fractal structure for improving grease extraction

The invention relates to the technology of biomass energy utilization, and aims to provide a method of using ultrasonic wave to change a wet alga cell fractal structure for improving grease extraction. The method comprises the following steps: obtaining wet alga with the fractal dimension of 1.21-1.24 and the cell wall thickness of 0.07-0.08 microns, then performing ultrasonic irradiation to modify the wet alga, controlling power and time of the ultrasonic irradiation to increase the fractal dimension of the cells in the wet alga to 1.46-1.51 and reduce the cell wall thickness to 0.04-0.06 microns, adding an extraction agent to the processed wet alga, and performing grease extraction, wherein the wet alga cells are aggregates of the microalgae cells with a moisture content of 10-90%. According to the method of using ultrasonic wave to change the wet alga cell fractal structure for improving grease extraction, disclosed by the invention, the high energy consumption steps such as dewatering and drying of the wet alga cells in the conventional method can be avoided; the alga cell fractal dimension can be improved and the cell wall thickness can be reduced; the extraction efficiency of the extraction agent to grease in the cells can be increased to 85-90%.