Wara Dyah Pita Rengga, Widya Hary Cahyati, Nunes Andayani
Using cooking oil at high temperatures can increase oil damage due to the formation of free fatty acids, which can be reduced by adsorption. Adsorption of Free Fatty Acids in Low Levels can still be improved using lamtoro char converted into activated carbon. Determining the equilibrium and thermodynamics of Lamtoro carbon as an adsorbent for frying tofu cooking oil is targeted in the research. Lamtoro activated carbon assistant ratio of 1:1.5 (Carbon:KOH). Furthermore, the mixture of materials is heated using a furnace at a temperature of 800 oC. The activated carbon is then washed and neutralized, sieved with a grain size of 400 mesh, and then granulated to a sieve size of 8-16 mesh. The adsorption process was carried out for 6 hours with a ratio of 1% (w/w) adsorbent to the weight of the used cooking oil. The characterization test was on the O-H hydrogen bonding ability between activated carbon and cooking oil. The Freundlich isotherm best describes the adsorption equilibrium (R2>0.93). Thermodynamic parameters, including enthalpy change, free energy, and entropy, were evaluated at 32-40 °C. Adsorption is endothermic and involves physical adsorption, indicating a spontaneous adsorption process. It can be recommended for processing used cooking oil in household kitchens. © 2024 Author(s).
Chemical Engineering Department, Universitas Negeri Semarang, Semarang, 50229, Indonesia; Public Health Department, Universitas Negeri Semarang, Semarang, 50229, Indonesia
