Lipase Activity of Tropical Oilseed Plants for Ethyl Biodiesel Synthesis and Their Typo- and Regioselectivity

The aim of this work was to investigate lipase activities in crude extracts from Adansonia suarezensis, Adansonia grandidieri, Moringa drouhardii, Moringa oleifera, Jatropha mahafalensis, and Jatropha curcas seeds in ethanolysis and hydrolysis reactions. All crude extracts from germinated seeds showed both ethanolysis and hydrolysis activities. The influence of germination, the delipidation procedure, and the triacylglycerol/ethanol molar ratio on their ethanolysis activity was studied. Crude extracts of Jatropha and Adansonia seeds showed optimal activity at pH 8 with an optimum temperature of 30 and 40 degrees C, respectively. The study of the regioselectivity of crude extracts from J. mahafalensis and A. grandidieri seeds,,which had the most active hydrolysis reaction, showed 1,3 regioselectivity in the hydrolysis reaction of vegetable oils. The crude extract from A. grandidieri seeds showed no typoselectivity, whereas the typoselectivity of the crude extract of J. mahafalensis seeds depended on the type of reaction

Solvent-Free Biodiesel Production Catalyzed by Crude Lipase Powder from Seeds: Effects of Alcohol Polarity, Glycerol, and Thermodynamic Water Activity

The aim of this work was to evaluate the potential of crude lipase powders made from Adansonia grandidieri and Jatropha mahafalensis seeds for the synthesis of fatty acid alkyl esters in a solvent-free system. The influence of the nature of the alcohol, the amount of glycerol, and hydration of the powder was investigated. Results showed that the activity of these crude lipase powders was inversely proportional to the alcohol polarity and the amount of the glycerol in the reaction medium. To ensure optimum activity, A. grandidieri and J. mahafalensis powders must be conditioned to a water activity of 0.33 and 0.66. To obtain a fatty acid ethyl ester yield greater than 95% with A. grandidieri, ethanol should be introduced at an amount corresponding to a triacylglycerol to ethanol molar ratio of 2:1 every 15 h for 96 h and use 25% of preconditioned crude lipase powders (2 additions of 12.5%)

Building TiO2-doped magnetic biochars from Citrus sinensis peels as low-cost materials for improved dye degradation using a mathematical approach

TiO2-doped ferromagnetic (TiFeBC) composites were synthesised from lignocellulosic orange peel biochar (BC) material using co-precipitation method. Several characterization techniques (XRD, SEM, EDX, FT-IR, EIS and N2 adsorption-desorption) were used to confirm the presence of Fe3O4 and TiO2 particles impregnated within the carbonaceous matrix of the biochar. Electrochemical impedance spectroscopy revealed that the sample obtained using 2.5 wt. % of TiO2 (TiFeBC1) has the lowest charge transfer resistance compared to those of 5 wt.% and 7.5 wt.%. TiFeBC1 was used for the optimization of the degradation of reactive yellow-145 from Cameroon Textile Industry using Fenton process. Optimum operational parameters were found to be: pH of 2.02, initial dye concentration of 75 mg/L, mass of material of 5998 mg/L and a time of 16.01 min. Using the CCD of the Response Surface Methodology, a predicted optimum response of 98.89 % was obtained in agreement with an experimental response of 97.95 % of dye degradation. Analysis of variance presented good correlation between the experimental data and the postulated model (R2 = 94.24 % and R2adjusted = 87.52 %). The degradation reaction was found to obey the first order kinetic rate law (R2 = 0.986) with respect to the dye. The study of interfering processes revealed that adsorption and H2O2/daylight-assisted degradation are two phenomenon that could possibly contribute to a negligible extent to the elimination of the dye during the Fenton process. The stability and efficiency of TiFeBC1 was evaluated over ten cycles and the material was found to lose approximately 5 % of its efficiency