Research of influence of ultrasound on the extraction process of vegetable oil

Abstract

The object of research is the process of oil extraction without using and using ultrasound for various solvents and types of plant materials. Extraction of oil provides maximum degreasing of vegetable raw materials in comparison with other methods, in particular by mechanical pressing. The extraction process is carried out by mass transfer and consists of mass transfer from the surface of solid particles of pre-ground vegetable raw materials and molecular diffusion inside the particles. The mass return from the surface of solid particles to the solution depends on the hydrodynamic conditions of washing the particles and occurs mainly due to convective diffusion. Various physical factors are used to intensify the process of extracting oil from vegetable raw materials, but the most promising is ultrasound. In the course of the study, the ultrasonic device UZP-6-1 (manufacturer: MEDPROMPRYLAD, Ukraine) is used. Extraction of oil from flax seeds is carried out by extraction with gasoline and methylene chloride, and for soybean meal is used with methylene chloride. For a comparative evaluation of the effect of ultrasound on the extraction of oil from various raw materials for flax seeds and soybean meal, experiments are carried out without using ultrasound. The research results show that extraction with methylene chloride from flax seeds and soybean meal under ultrasound conditions increases the oil yield. This is due to the fact that under the action of ultrasonic waves, there is a movement of fluid around solid particles, due to alternating powerful ultrasonic pressure and hydraulic shocks at the moment of collapse of cavitation cavities. Ultrasonic cavitation has a destructive effect on solid particles and leads to the appearance of additional microcracks on the surface. This contributes to the acceleration of diffusive mass transfer inside solid particles. This makes it possible to reduce the duration of the extraction process and increase the productivity of the extraction equipment. Thus, when extracting oil from crushed flax seeds with methylene chloride under ultrasound conditions, the oil yield increases by 4.5 %.