ADSORPTION OF β-CAROTENE FROM VEGETABLE OIL ON PILLARED MODIFICATIONS OF MONTMORILLONITE

This work investigates the efficiency of adsorptive refining of vegetable oil, evaluated by β-carotene adsorption, using different forms of synthesized pillared montmorillonite (PMM) obtained by intercalation of large-sized hydroxocomplexes [Аl13О4(ОН)24(Н2О)12]7+, [Al30O8(OH)56(H2O)24]18+, as well as complexes - products of aluminium and cerium co-hydrolysis. Pillaring is considered as an alternative to acid activation of montmorillonite for oil bleaching. The periodic pillar structure of PMM provides a developed specific surface area and regular distribution of mesopores, as well as the presence of active centres of different nature. The textural characteristics of the original montmorillonite and its pillar modifications were measured using nitrogen adsorption-desorption method. The textural feature of Al30-PMM is the maximum pore space volume (0.173 cm3/g), while Al/Ce-PMM has the maximum value of specific surface area (154 m²/g) and the minimum average pore diameter (5.6 nm). Kinetic curves of β-carotene adsorption at temperatures of 20, 40, 60 and 90 °C at a dosage of 1 g of adsorbent per 20 ml of oil were obtained using the photometry method. It was found that for all temperatures there is a tendency of increase of sorption capacity in the series: montmorillonite (MM), Al13-PMM, Al30-PMM, Al/Ce-PMM, which correlates with the increase in the value of specific surface area of the adsorbent in this series. Increasing the temperature from 20 to 90 °C leads to an increase in bleaching efficiency of up to 20 per cent. The kinetics of the sorption process is described by pseudo-first and pseudo-second order kinetic models. From the temperature dependences of the equilibrium constants, the enthalpies of β-carotene adsorption were obtained, monotonically increasing in the MM, Al13-PMM, Al30-PMM, Al/Ce-PMM series. Their values (5.6-22.3 kJ mol-1) indicate the physical nature of adsorption. For citation: Butman M.F., Ovchinnikov N.L., Yashin D.V. Adsorption of β-carotene from vegetable oil on pillared modifications of montmorillonite. ChemChemTech [Izv. Vyssh. Uchebn. Zaved. Khim. Khim. Tekhnol.]. 2025. V. 68. N 4. P. 33-40. DOI: 10.6060/ivkkt.20256804.7119.