The present study investigates the transesterification of corn oil with methanol over two oxides of MgO and ZnO at 65 ͦC and 1 atm. These two catalysts have been prepared via a conventional co-precipitation process. As for MgO, the corresponding mixed metal nitrate solution has been mixed and heated at the presence of urea. ZnO has also been synthesized by co-precipitation of metal acetate at the presence of oxalic acid and ethanol. The catalysts then have been characterized by means of X-Ray Diffraction (XRD) and Scanning Electron Microscope (SEM). XRD results indicate high purity for both catalysts. Also, catalytic activity has been evaluated in methanol reflux temperature through corn oil transesterification, with the impacts of reaction variables, like catalyst amount, methanol/oil molar ratio, and reaction time on biodiesel yield, investigated by means of HNMR spectrum. Under appropriate transesterification conditions at 65 °C (catalyst amount= 5%, methanol/ oil ratio= 20, and reaction time= 10 hr), an ME content of 62.61% can be achieved, using MgO catalyst. Similarly, the experiments have been repeated to achieve the best yield, using ZnO catalyst, with the highest rate, equal to 53.1%, obtained in 9% of catalyst and methanol/oil ratio of 30 over 10 hr. Furthermore, reusability of ZnO and MgO has been evaluated in transesterification reaction.

We performed toxicological study of mice exposed to lead by quantifying fatty acids in brain of the mice. This study suggests that the introduced analytical method had an extremely high tolerance against impurities such as water and extractives; thus, it led to the enhanced resolution in visualizing the spectrum of fatty acid profiles in animal brain. Furthermore, one of the biggest technical advantages achieved in this study was the quantitation of fatty acid methyl ester profiles of mouse brain using a trace amount of sample (e.g., 100 μL mixture). Methanol was screened as the most effective extraction solvent for mouse brain. The behavioral test of the mice before and after lead exposure was conducted to see the effect of lead exposure on fatty acid composition of the mice’ brain. The lead exposure led to changes in disease-related behavior of the mice. Also, the lead exposure induced significant alterations of fatty acid profile (C16:0, C 18:0, and C 18:1) in brain of the mice, implicated in pathology of psychiatric diseases. The alteration of fatty acid profile of brain of the mice suggests that the derivatizing technique can be applicable to most research fields associated with the environmental neurotoxins with better resolution in a short time, as compared to the current protocols for lipid analysis.

A method based on phospholipid fatty acid (PLFA) analysis for profiling microbial communities in offshore produced water was optimized. The operation parameters affecting final PLFA profiling performance from the solid phase extraction (SPE) purification and fatty acid methyl esters (FAMEs) yielding process were investigated. Under the selected conditions, 92.9%, 96.3% and 92.8% of the spiked phospholipid standards C16:1 (cis-9) PC, C18:1 (cis-9) PC, and C19:0 PC were recovered, respectively, using 10mL methanol as elution solvent on a non-commercial SPE column. Over 90% of spiked C19:0 PC was recovered before sample transesterification. Four parameters including alkaline reagent, volume of acid for neutralization, time and temperature for FAMEs derivatization were examined. Gas Chromatography-Mass Spectrometry (GC-MS) was used to analyze FAMEs and the method linearities, recoveries of 29 FAMEs during transesterification, detection limits, relative standard deviations were presented. The results provided valuable information for biological reservoir souring control.

This paper for the first time synthesizes novel biodiesel experimentally using low-cost feedstocks of coconut oil, caustic soda, and fermented palm wine contaminated by microorganisms. The alkaline catalyzed transesterification method was used for biodiesel production with minimal glycerol. The produced biodiesel was biodegradable and effective in cleaning a shoreline oil spill experiment verified by our developed oil spill radial numerical simulator. For the first time, an adaptive neuro-fuzzy inference system (ANFIS) was hybridized with invasive weed optimization (IWO), imperialist competitive algorithm (ICA), and shuffled complex evolution (SCE-UA) to predict biodiesel yield (BY) using obtained Monte Carlo simulation datasets from the biodiesel experimental seed data. The test results indicated ANFIS-IWO (MSE = 0.0628) as the best model and also when compared to the benchmarked ANFIS genetic algorithm (MSE = 0.0639). Additionally, ANFIS-IWO (RMSE = 0.54705) was tested on another coconut biodiesel data in the literature and it outperformed both response surface methodology (RMSE = 0.72739) and artificial neural network (RMSE = 0.68615) models used. The hybridized models proved to be robust for biodiesel yield modeling in addition to the produced biodiesel serving as an environmentally acceptable and cost-effective alternative for shoreline bioremediation.

This work examines the effect of ultrasound irradiation (UI) on biodiesel properties and transesterification parameters. Methanol content, reaction time, reaction temperature, and catalyst concentration are varied, and the optimum condition for maximum possible yield was held constant for both processes. Biodiesel obtained from non-edible oils is the most promising alternative fuel for conventional diesel fuel. In this study, sterculia foetida seed oil was used for biodiesel production. Sterculia foetida oil was transesterified to lower its FFA using UI and compared with the conventional process. Both heating processes were optimized to yield a maximum of 94.3% at a six molar ratio, 50 °C, (water temp), 1% wt of catalyst (KOH), and 75 min reaction time. Transesterification by UI reduced the total reaction time to 4 min compared to 75 min at the conventional process. Further UI influenced the properties of biodiesel (SOBD) from SO. UI lowered viscosity by 7.3% and density by 5.5% and facilitated using oxygen content of SOBD.

Scale-up and commercialization of biodiesel is often delimited by costly feedstock that adds up to the process costs. These underlying issues demand the exploration of unconventional cheap feed to improve the process economics. Conversion of waste cooking oil (WCO) into biodiesel could reduce the process costs by 60–70%. However, the continuous exposure to heat during frying leads to oxidation as well increase in the free fatty acid (FFA) content which intensifies the time and energy required for transesterification. The present study analyzes the effect of parameters over the conversion of WCO (with 8.17% FFA) into biodiesel via two-step acid-alkali-based microwave-assisted transesterification. Response surface methodology (RSM) was used to optimize the oil:methanol volume ratio, microwave power, and reaction time during the acid-catalyzed esterification to bring down the FFA below 1%. Microwave irradiation of 250 W, with methanol:oil molar ratio of 19.57:1 [oil:methanol volume ratio of 1.31 (expressed as decimal)] and reaction time of 35 s, resulted in 0.082% of FFA. Alkali-catalyzed transesterification with methanol:oil molar ratio of 5:1 with 2% sodium hydroxide at 65 °C thereby produced fatty acid methyl esters (FAMEs) with the volumetric biodiesel yield of 94.6% in 30 min. Physiochemical properties of the transesterified WCO were well comparable with the biodiesel standards. The study highlights the essentiality of multivariate optimization for the esterification process that could aid in understanding the interactive effects of variables over FFA content. Such studies would benefit in scaling up of the transesterification process at industrial level by improving the economics of the overall bioprocess.

The presented study discusses biodiesel synthesis by utilizing two wastes: Mesua ferrea Linn (MFL) seed shells (inert support for developing catalysts) and used cooking oil (feedstock). The MFL shells were used for heterogeneous acid and base catalyst development through carbonization, steam activation and subsequent doping of H₂SO₄ or KOH, which upon instrumental examination showed effective doping of functional groups on the MFL char. The conversion approach uses methanol with sulfonated char (SC) for esterification, while the second stage utilizes 2-propanol for transesterification with KOH-doped char (KC) as a catalyst. Both stages optimize 5 controlling parameters such as mixing intensity, duration of reaction, catalyst load, alcohol concentration and reaction temperature in an L16 Taguchi experimental matrix. Thus, the obtained biodiesel has an ester content of 99.16%, while 97.35% of the free fatty acids (FFA) were converted, resulting in the product showing improved physico-chemical properties as assessed through fuel characterization tests. Reusability tests for the catalysts showed 4 reuses for acid catalyst compared to 9 reuses for base catalyst. Catalyst development costs were only $1.27/kg for activated char, while due to reuse, the prepared catalysts cost only $0.53/kg of biodiesel. Hence, the catalytic process holds great potential for commercialization if scaled up appropriately.

High volumes of wastewater with high pollutant concentration form in the transesterification stage of the process applied for biodiesel production from waste vegetable oils. In this study, application of the advanced electrocoagulation process following acidification was investigated in the biodiesel wastewater treatment. Through the acidification step of the sequential process, respectively, 25.4%, 68.7%, and 50.0% removal efficiencies for COD, oil-grease, and volatile fatty acids (VFAs) were obtained. Electro-activated persulfate (EAP) oxidation was modeled and optimized by using the response surface methodology and Box–Behnken design. The effect of independent variables (current, persulfate/COD ratio, time) on COD, oil-grease, VFAs removal, and total cost and the interaction of the variables of the process were determined. The maximum oil-grease removal efficiency predicted by using the model was 98.3% under the optimum conditions (current: 4 A, persulfate/COD: 4.4, and time: 15 min), whereas oil-grease removal efficiency obtained by the verification experiments performed at optimum conditions was found to be 97.2%. Sequential acidification–EAP process is an appropriate treatment method for biodiesel wastewater with high oil-grease concentration, and response surface methodology is a powerful tool for optimizing the operational conditions of EAP oxidation for COD, oil-grease, VFAs removal, and total cost.

One of the dominating meat supply industries, the poultry chicken sector, is facing waste management concerns worldwide. Due to high oil content containment, biofuel researchers emphasized poultry waste as abundant, cheap, and high-quality feedstock for biodiesel production. Therefore, in the current study, an experimental investigation of biodiesel production from wasted chicken skin through the transesterification process has been performed. The chicken skin used in this study for biodiesel production can be used as the potential waste source for biodiesel production worldwide. Techno-economic, environmental, and sustainability analyses were also performed. During the synthesis, the reaction was conducted with potassium hydroxide (KOH), and the process yielded 48% biodiesel. The cost of electricity for providing electricity is estimated at US$0.575 per kWh when an auto-sized generator has been fueled by biodiesel. The environmental and substantiality analysis found that biodiesel is more suitable than conventional diesel as an environmentally friendly and sustainable fuel.

In this research work, the characterization of the palm stearin biodiesel was made using Nuclear Magnetic resonance (NMR), Fourier transform infrared spectroscopy (FITR) and GC/MS methods. Analysis of the composition of fatty acids was done using the GCMS apparatus based on the retention time. Fourier transform infrared spectrometer was used for the spectrum analysis of the various functional groups and bands located in it. The properties of the palm stearin biodiesel were predicted adopting the American Society for Testing and Materials (ASTM) standards. Measured values of the properties were the density at 18°C as 0.88 g/m3, kinematic viscosity at 35°C as 3.4 mm2/s, the calorific value of the palm stearin as 37121 kJ/kg and the flash and fire points of the biodiesel as 130°C and 160oC respectively. The rapid and correct characterization of the palm stearin biodiesel was made by the NMR.