Author(s):
1. Zoran Petrović, Univerzitet u Istočnom Sarajevu.Tehnološki fakultet Zvornik, Republic of Srpska, Bosnia and Herzegovina
2. Ana Đokić, Serbia
3. Pero Dugić, Faculty of Technology Banja Luka, Republic of Srpska, Bosnia and Herzegovina
4. Tatjana Botić, Faculty of Technology Banja Luka, Republic of Srpska, Bosnia and Herzegovina
5. Dragana Kešelj, Republic of Srpska, Bosnia and Herzegovina
6. Nebojša Vasiljević, Univerzitet u Istočnom Sarajevu Tehnološki fakultet Zvornik, Republic of Srpska, Bosnia and Herzegovina
7. Marija Jevtić, Zeochem doo Zvornik, Republic of Srpska, Bosnia and Herzegovina

Abstract:
Natural bentonites are widely used in various adsorption processes due to their structural and chemical composition, as well as the possibility of modification by various procedures, among which chemical modification procedures are most often used. The effects of chemical activation of bentonite depend on the activation conditions, such as: type of acid or alkali, mass concentration of the activation agent, ratio of the activation agent and bentonite, activation temperature and contact time. Various modern test methods are used to determine the effects of activation, some of which are: XRD, FTIR, BET, SEM/EDS, laser method. In the process of refining rapeseed oil, the bleaching method is carried out using commercial bleaching earths or active clays. In this paper, the chemical activation of pre-calcined bentonite was performed using 8% m/m solutions of hydrochloric acid (HCl) and sulfuric acid (H2SO4) at the following parameters: temperature 95°C, contact time 180 minutes, ratio of bentonite and acid solution 1:5. The analysis of the results of testing samples of activated bentonite showed that the effects of activation on the specific surface are significantly better when using HCl solution (316.28 m2/g) compared to H2SO4 solution (193.04 m2/g). In the continuation of the research, the effects of 8% HCl activated bentonite in the rapeseed oil bleaching process were examined, compared to commercial bleaching earth. The bleaching parameters were: temperature 95°C, time 30 minutes, doses of bleaching agent: 0.2, 1, 2 and 3 % w/w. To determine the effects of bleaching, the methods of testing rapeseed oil samples before and after bleaching, prescribed by the relevant national regulations, were carried out. The obtained results showed that the bleaching effects of rapeseed oil with HCl activated bentonite are similar to or better than the effects of commercial bleaching earth: there are no residual soaps in oil samples after bleaching, the peroxide number is lower, by application of a higher dose of activated bentonite the color change is more significant, and the GC method determined that there was a slight change in the fatty acid composition.

Key words:
bentonite,acid activation,bleaching,rapeseed oil,bleaching earth

Thematic field:
SYMPOSIUM A - Science of matter, condensed matter and physics of solid states

Date of abstract submission:
25.08.2023.

Conference:
Contemporary Materials 2023 - Savremeni materijali

Abstract