Continuous solvent extraction of sunflower, seed, groundnuts, palmkernels, rapeseed, and copra

Abstract

In principle, the oil milling process is straightforward. The wide variety of equipment in use reflects, however, a multiparametric process. The main limiting parameters are kind of seed, oil content, particle strength, particle structure, temperature, moisture, particle size, residence time, mechanical forces, etc. Additionally, the seed specific parameters vary not only between kinds of seed but also for the same seed, due to different conditions in climate, soil, and harvesting. Therefore, equipment design must be widely based on statistical averages of the limiting parameters. In other words, exact precalculation of the single technological steps is impossible. As a consequence, for more than 5,000 years, the oil milling process has been in the stage of being optimized. The acutal technical standard is very satisfying, but there is still a strong need for further research and development. Currently, as in the past, the oil milling process seems to be not so much a science as an art.

Dry Heating of Palm Fruits: Effect on Selected Parameters

“…Solvent extraction has been practiced in the extraction of oil from soybeans, sunflower seeds, rapeseed, corn and palm kernels, as well as pressed palm fibre (Stein and Glaser, 1976). Solvent extraction gives higher yields than conventional screw pressing.…”

The effect of rapeseed microstructure on the mechanism of solution and diffusion extraction

“…Commercial solvent extraction equipment is designed to reduce residual oil content to approximately 0.5-1 wt% [1][2][3]. The aim of this study was to carry out successive solvent extraction of laboratory-made rapeseed cake previously prepressed with maximum oil yield.…”

“…Understanding of the oil transfer mechanism from the first and final stage of the oil extraction process is important to design commercial equipment. The combination of prepressing and solvent extraction techniques is necessary in the case of the rapeseeds [1][2][3]. The recovery of crude lipids is increased by preliminary mechanical and thermal preparation steps.…”

“…The recovery of crude lipids is increased by preliminary mechanical and thermal preparation steps. Rolling between smooth rolls ensures high pressure to reduce the seed size in order to expand surface area and to break the cell walls ordinary non-permeable for the oil [1][2][3]. For the efficient transport and separation of crude oil or miscella, from mechanically ruptured cell, porous structure has to be formed.…”

“…Particle size is a significant factor affecting the rate of oil extraction, and effective extraction size is determined by thickness. Production of fines is not desirable in designing pilot plant operations [1][2][3][4][5].…”