Modeling and optimization of two-step shea butter oil biodiesel synthesis using snail shell as a heterogeneous base catalyst

Shea butter oil (SBO) is underutilized in the biodiesel production industry in Nigeria because of its high free fatty acid (FFA) which reduces its biodiesel yield. This research aimed at...

Green Heterogeneous Base Catalyst from Ripe-Unripe Plantain Peels for the Transesterification of Waste Cooking Oil

Economical feedstocks such as agricultural wastes, food wastes, and waste cooking oil were used for biodiesel production to expand their application. Thus, a solid base catalyst was synthesized from a mixture of ripe and unripe plantain peels at a calcination temperature of 500 oC for 4 h. The catalyst was characterized using Scanning Electron Microscope (SEM), X-ray Diffraction (XRD) analysis, Fourier Transform Infrared (FT-IR) spectroscopy, Energy dispersive X-ray (EDX) analysis, and Brunauer-Emmett-Teller (BET) method. The waste cooking oil (WCO) used in this study was first pretreated with 3% (v/v) of H2SO4 via esterification reaction due to its high acid value. The esterified WCO was converted to biodiesel via transesterification reaction, and the process was then modeled and optimized using Taguchi L9 orthogonal array design method considering reaction temperature, reaction time, catalyst amount, and methanol/WCO molar ratio as the input variables. Based on the results, the synthesized catalyst predominantly contained potassium phases with 45.16 wt.%. The morphology of the catalyst revealed a crystalline mesoporous nanocomposite. At the end of WCO esterification, the acidity of the oil decreased from 5 to 1 mg KOH/g. The optimal conditions established for the transesterification process were catalyst amount of 0.5 wt.%, methanol/WCO molar ratio of 6:1, reaction temperature of 45 oC, and reaction time of 45 min with a corresponding biodiesel yield of 97.96 wt.%. The quality of the biodiesel produced satisfied the specifications (ASTM D6751 and EN 14241) recommended for biodiesel fuels. Hence, a blend of ripe and unripe plantain peels could serve as an efficient heterogeneous base catalyst in producing biodiesel from WCO.

Synthesis of Glycerol Carbonate from Glycerol and Dimethyl Carbonate Catalyzed by Solid Base Catalyst Derived from Waste Carbide Slag

Na2CO3 was loaded onto waste carbide slag (CS) by impregnation-calcination method to prepare the solid base catalyst, which was used to synthesize glycerol carbonate (GC) by the transesterification of glycerol with dimethyl carbonate (DMC). The prepared catalysts were characterized by a scanning electron microscope (SEM), thermogravimetric analysis (TGA), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and Brunner−Emmet−Teller (BET) techniques. The catalyst 15 wt.% Na2CO3-CS-800, which was prepared by impregnating CS to the Na2CO3 solution with the concentration of 15 wt.% weight of CS and calcined at 800°C for 3 hours, showed an excellent catalytic ability. When it was applied in the catalytic synthesis of GC, 98.1% glycerol conversion and 96.0% GC yield were achieved in 90 mins at 75°C with the catalyst dosage of 3 wt.% to total reactants and the DMC to glycerol molar ratio of 5. More importantly, the loading of Na2CO3 can effectively improve the reusability of catalyst. The 15 wt.% Na2CO3-CS-800 can still achieve 83.6% glycerol conversion and 80.5% GC yield after five-time reuse. Meanwhile, under the same reaction conditions, the CS-800, which was obtained by calcining CS at 800°C for 3 hours, experienced significant activity reduction with only 15.2% glycerol conversion and 14.1% GC yield after five-time reuse. FTIR and XRD characterization revealed that CO32- might play a key role in preserving active catalytic CaO component by forming protective CaCO3 shell on the catalyst surface.

Effect of Calcination on Shell Powder Catalyst Towards Effectiveness on Catalysing Transesterification of Crude Glycerol to Glycerol Carbonate

Valorisation of crude glycerol has gained much interest in the industry associated with the surplus of crude glycerol caused by the increase usage of biodiesel. Transesterification of crude glycerol using a heterogenous base catalyst is one of the effective ways to utilize the additional glycerol. Seawater clams commonly serve as a food source to us and the waste shells are a source of calcium carbonate that is abundantly available and can be converted into a heterogenous base catalyst for the transesterification process. Therefore, this study focuses on the utilization of catalyst synthesized from a species of seawater clam, Paratapes Undulatus in a transesterification reaction using crude glycerol (C.GLY) as a reactant together with dimethyl carbonate (DMC) to synthesize glycerol carbonate (GLYC). The catalysts are characterized using Field Emission Scanning Electron Microscope (FESEM), Attenuated Total Reflectance (ATR), Thermogravimetric Analysis (TGA), X-ray diffraction (XRD) and Particle Size Analyser (PSA). The product is characterized using Gas Chromatography (GC-FID). The performance of the synthesized shell catalyst with different calcination condition was studied. The reaction using the calcined shell catalyst is carried out at 75°C, molar ratio of 2 and 2wt% of catalyst for 1 hour. The catalyst that has the best performance is the shell catalyst that is calcined for 3h, which give the yield of 54.16%.

Synthesis of Carbide Lime Waste Derived Base Catalyst (KF/CLW-Fe3O4) for Methyl Ester Production: An Optimization Study

In this paper, solid base catalyst KF/CLW-Fe3O4 was prepared from carbide lime waste, primarily calcium hydroxide with tiny amounts of carbonate and; the catalyst was used in the optimization study on the methyl ester production. The new strong base catalyst was synthesized by chemical impregnation. This catalyst was characterized by Hammett indicator analysis, Brunauer, Emmett, and Teller (BET), scanning electron microscope (SEM), X-ray diffraction (XRD) and temperature-programmed desorption (TPD) of carbon dioxide. The catalyst was further used to catalyzed the transesterification reaction to produce methyl ester. Taguchi method was used to assess the impact of catalyst at different intervals of reaction parameters, including reaction time, methanol to oil ratio, and catalyst loading. A mixed level of orthogonal array design with L9, analysis of variance (ANOVA) and signal to noise ratio were used to determine parameters that significantly impact the palm oil transesterification reaction. High methyl ester conversion was attained, and the catalyst can be easily separated and reused. KF/CLW-Fe3O4 has great potential to be used to produce methyl ester because of its high catalytic activity and environmental friendliness. Copyright © 2021 by Authors, Published by BCREC Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).