Research

Purification of plant oils using VLA

Plant oil producers successfully use the vortex layer apparatus. Taking into account the peculiarities of processing components in the VLA working area, its effectiveness has been proven when introduced into technological lines of refining and hydration of vegetable oils. The processing of the vortex layer in the VLA also allows improving the quality of oil, intensifying the production process, and improving technological lines.

Plant oils are a complex system of organic compounds, the main part of which are lipids. The largest group among lipids are fats (triacylglycerol), phospholipids (glycerophosphatides), waxes and their derivatives.

When storing oils, phospholipids absorb moisture from the environment and form a watered precipitate, which degrades the quality of oils. The use of VLA allows you to completely eliminate this problem.

To remove phospholipids from plant oil, it is necessary to disrupt the stability of the system of phospholipids-triacylglycerol by increasing the polarity of phospholipid molecules. For example, by the action of water, which has a high polarity. As a result of the action of water, hydrate shells appear around polar phospholipid molecules. As a result, the phospholipids-triacylglycerol system becomes unstable and hydrated phospholipids precipitate. The isolated precipitate is dried and a phosphatide concentrate is obtained, which is used for food and feed purposes. Therefore, in modern technological schemes of plant oil refining, an important operation, simultaneously with the removal of free fatty acids, is the process of its hydration with water or weak aqueous solutions of alkali, salt or acid, which allows you to remove phospholipids from the oil and prepare the oil for the next stages of refining.

The process of hydration of phospholipids from vegetable oil is based on an important property of phospholipids — their relation to the action of water. Hydration consists in the fact that water or a reagent solution with a temperature of 40-50 °C is introduced into the oil heated to the desired temperature while stirring.

The integration of VLA into the technological line of hydration of plant oil allows not only to intensify, but also to improve this process.

Water while interacting with hydrophilic groups of phosphatides, leads to the formation of mixed layers. They simultaneously contain glyceride molecules and hydrated phospholipid molecules. Despite the fact that hydration has been used in industry for a long time, the mechanism of interaction of phosphatides with water requires further study because the technological schemes for its implementation are imperfect and do not provide a guaranteed degree of phospholipid extraction. The authors found that the hydration process is significantly affected by the amount of water injected and the temperature of the process.

Technical progress in the field of purification of technical oils covers a wide range of issues of intensification of technological processes, namely:
- selection of optimal hydrating agents and hydration conditions depending on the type of oils;
- improvement of prescription and technological factors;
- the use of various technological techniques in the hydration process in order to impart specific properties to oils and improve their quality;
- application of various physical methods of process intensification.

Great opportunities for the intensification of oil hydration processes lie in the improvement of devices operating using various physical methods of influencing the materials that are processed in them.

In the technological process of oil purification, operations related to mechanical mixing of components occupy an important place. The equipment used in these operations does not provide the necessary quality of mixing and contacting of components, which leads to overspending of raw components and does not provide guaranteed stability and quality of oil purification. Taking into account the features of processing multicomponent systems in VLA, described in our previous materials, the authors conducted studies of the effectiveness of using electromagnetic devices with a vortex layer in technological schemes of refining plant oils.

VLA provides the necessary mixing quality of components and oil stability, and leads to better economy of components.

Raw oil (sunflower, rapeseed, coriander, mustard) was used as the object of research. Hydration was carried out with distilled water in a VLA with an inductor bore diameter of 100 mm (at an electromagnetic field strength of H = 11.8 • 104 A/m). Ferromagnetic cylindrical particles made of SHX-15 steel with a diameter of 1.6 mm and a length of 17.8 mm were used as working elements. The influence of the amount of ferromagnetic elements (m = 100-250 g), the duration of treatment (τ = 3 -30 s), the amount of water (3-5% by weight of oil) on the hydration efficiency was studied. Ferromagnetic elements, oil in the amount of 0.3 dm3 were loaded into the reactor with a volume of 0.5 dm3 and heating was carried out. Distilled water was heated separately in the tank. To achieve the required temperature, a thermoshock was used.

The hydration process was carried out at a temperature of 30-75 ° C. The heated water was poured into the reactor with oil, which was located in the working area of the ABC for the appropriate time. Due to the complex action of the vortex layer and the magnetic field of the inductor, intensive mixing of the components was achieved, which provided the necessary conditions for the effective flow of the oil hydration process. After processing in VLA, the hydrated oil was loaded into a laboratory centrifuge to isolate phospholipids (the centrifugation time was 10 minutes at n = 5000 rpm) or poured into a laboratory stirrer, where the hydrated oil was processed for a certain time at a hydration temperature followed by centrifugation. During the studies, the following were controlled: acid number (GOST 5476-80), ash content (GOST 5474-66), the amount of phosphorus-containing substances by weight (GOST 7824-80), the content of unsaponified substances (GOST 5479-64).

The results of the studies are presented in Table 1.

The analysis of the obtained results shows that the effectiveness of oil hydration in VLA is influenced by the amount of water, the hydration temperature, the intensity of treatment in the vortex layer, as well as the duration of treatment in the apparatus with a stirrer.