Recovery of oil and free fatty acids from spent bleaching earth using sub-critical water technology supported with kinetic and thermodynamic study

Abstract

This work represents the extraction of oil with high free fatty acid content from spent bleaching earth using sub-critical water technology as a greener production pathway. The extraction efficiencies under different conditions were investigated. The studied parameters include temperatures in the range of 180 to 270˚C, the feed to solventfeed-to-solvent (in this case water) ratio (1:1, 1:2, 1:3, 1:4 and 1:5) and extraction times in the range of 5-60 minutes. The results showed that the optimum temperature, feed to solventfeed-tosolvent ratio, and extraction time were 270˚C, 1:3, and 20 minutes, respectively. In another experiment, the extracted free fatty acids were converted into mono-, di-, and triglycerides through esterification with glycerol to increase the value added of the extracted products. The kinetics of the extraction process was found to be corresponding to an irreversible consecutive unimolecular-type first order reaction, consisting of the extraction step followed by the decomposition reaction step. Both reaction rates of extraction and decomposition were estimated using the reaction rate equations utilizing the nonlinear regression method. The apparent activation energy was calculated to be 46.1 kJ•mol −1. This result indicates a diffusion controlled reaction. For more exploration and deep understanding of the extraction mechanism, other thermodynamic parameters were also calculated and analyzed including, ∆H#, ∆S#, and ∆G# of the extraction step.

The mechanism of hydrothermal hydrolysis for glycyrrhizic acid into glycyrrhetinic acid and glycyrrhetinic acid 3- O -mono-β- d -glucuronide in subcritical water

“…Eyring (1935) developed the activation complex theory (ACT), which is used to estimate thermodynamic parameters in terms of the rate constant. The theory is based on transition-state theory, which proposes that any chemical reaction carried out via an intermediate structure (called the activated complex) with transitory energies between reactants and products, the intermediate structure is in a quasi-equilibrium status with the reactants during the reaction (Fattah et al, 2014).…”

“…SW was used as an environmentally friendly medium for organic compounds and biomass hydrolysis to produce useful substances, such as cellulose decomposition (Matsunaga, Matsui, Otsuka, & Yamamoto, 2008), protein aggregation, disaggregation and hydrolysis (Rogalinski, Liu, Albrecht, & Brunner, 2008), recovery of oil and free fatty acids (Fattah, Mostafa, Mahmoud, & Abdelmoez, 2014) and hesperidin hydrolysis (Ruen-ngam, Quitain, Tanaka, Sasaki, & Goto, 2012). However, there is no information on the formation of GA and GAMG from GL in SW.…”

Pemanfaatan Limbah Spent Bleaching Earth pada Stabilisasi Tanah Lempung dengan Clean Set Cement

“…Pada penelitian ini, dilakukan eksperimen dengan memanfaatkan limbah SBE. SBE adalah limbah padat pada industri pemurnian minyak kelapa sawit (7) . Bleaching Earth (BE) yang merupakan lempung (clay) berjenis simnite atau bentonite yang telah diputihkan dan diaktivasi selanjutnya digunakan untuk memurnikan minyak mentah (8) , dan setelah berkurangnya kemampuan penyerapan karena kandungan minyak di dalamnya 20-30% BE tidak terpakai lagi dan dibuang menjadi limbah SBE (9) .…”

Use of Crude Glycerol for Glycerolysis of Free Fatty Acids in Crude Palm Oil

“…The prominent absorption bands from three types of samples appeared to be similar. The main functional groups and corresponding wavenumbers were as follows: ~3006 cm -1 for bending of C=C, ~2920 and ~2850 cm -1 for symmetrical and asymmetrical stretching of -CH2, ~1743 cm -1 for stretching C=O, ~1462 cm -1 for bending (scissoring) of -CH2, ~1161 cm -1 for stretching of C-O, and ~721 cm -1 for swing vibration of -(CH2)4 (Lerma-García et al, 2010;Fattah et al, 2014). These groups existed in CPO and glycerolyzed CPO.…”