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.

Lipases are utilized in biodiesel production utilizing various types of substrates. The use of lipase in bioenergy production aims to reduce energy crises and environmental pollution. Lipase-producing indigenous bacteria Bacillus licheniformis (Accession no. OP56979) and Bacillus rugosus (Accession no. OP56980) were isolated from various oil-contaminated sites. The isolated potential lipolytic bacteria were screened for maximum lipase production. Then, the bacteria showing the highest lipolytic activity were subjected to identification using the 16s rRNA technique while other isolated were identified biochemically. Lipase [LipBL-WII(c)] from Bacillus licheniformis having the highest lipolytic activity expressed various characteristics. Characterization of crude LipBL-WII(c) expressed that it showed stability in a wide range of pH (4 to 10) with optimum lipolytic activity observed at pH 8. It was then found to be active at a temperature range from 20°C to 80°C with optimal at 50°C. Lipase activity was also stimulated in metal ions such as Ca+1, Mg2+, and Zn2+ the most. Furthermore, LipBL-WII(c) retained lipolytic activity in the presence of various organic solvents and surfactants. The kinetic parameters (Km and Vmax) for LipBL-WII(c) were ascertained using Lineweaver- Burk plot. LipBL-WII(c) showed a potential for biodiesel production using olive oil as a source. Lipase gave 84% yield of biodiesel production from olive oil. Thus, it could be employed as a potential candidate for green biodiesel production using oil sources.

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 present work encompasses the production of biodiesel from an inexpensive waste, viz., used rice bran oil (URBO) through concurrent esterification and transesterification reactions employing the prepared waste duck bone (WDB)-derived natural hydroxyapatite (NAHAp) supported vanadium impregnated solid catalyst (VNAHAp). The optimal VNAHAp catalyst possessed 92.23 m²/g surface area which was much superior to 61.46 m²/g of the V-catalyst (VCHAp) prepared using commercially available hydroxyapatite (CHAp). The optimal (Box–Behnken design) concurrent trans/esterification reaction conditions for biodiesel (FAME) production from URBO and methanol were 5 wt.% catalyst concentration, 8:1 methanol/URBO mole ratio, and 35 wt% NH₄VO₃ loaded VNAHAp (35VNAHAp) catalyst that resulted in 99.05% FAME yield deploying a low-energy infrared radiator assisted batch reactor (LIRABR) which ensured significantly high FAME yield at milder temperature (60°C) and in shorter reaction time (30 min) compared to a conventionally heated batch reactor. The product biodiesel and its blend with commercial diesel conformed to ASTM D7467-10 specifications. The life cycle assessment (LCA) of the entire process advocated superior sustainability of the biodiesel production using 35VNAHAp catalyst in the LIRABR compared to their conventional counterparts. Valorization of two potential wastes, viz., URBO and WDB, under milder process conditions involving LIRABR and 35VNAHAp resulted in lower environmental impacts, thus rendering a sustainable biodiesel production process towards a greener earth.

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.

In the present research work, different types of biodiesel were produced by a homogeneous alkali transesterification reaction using soybean oil, pork lard, and castor bean oil as raw materials, to evaluate how their different compositions may affect the biodegradability, namely, in the presence of benzene. Biodiesel was characterized according to the European standard EN 14214. The anaerobic biodegradation of the different types of biodiesel was examined as well as its influence on the biodegradation of benzene. Analyses were performed to determine the volume of methane (directly related to the anaerobic biodegradation of biodiesel), the concentration of benzene over time, and the production of organic acids. The results showed methane production resulting from the anaerobic degradation of all biodiesel types. The differences between the degradation behavior of each fuel were negligible, contrary to what was expected; however, the amount of methane produced was low due to nutrient limitations. This fact was confirmed by the organic acid analysis as well as by the addition of new media. Anaerobic benzene biodegradation was found to be negatively impacted by the presence of all biodiesel types on average; therefore, the results of this study may impact management of sites that contain biodiesel and fuel hydrocarbon contamination.