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.

Semivolatile organic compounds (SVOCs) represent a dominant category of secondary organic aerosol precursors that are increasingly included in air quality models. In the present study, an experimental system was developed and applied to a light-duty diesel engine to determine the emission factors of particulate SVOCs (pSVOCs) and nonvolatile particulate matter (PM) components at dilution ratios representative of ambient conditions. The engine was tested under three steady-state operation modes, using ultra-low-sulfur diesel (ULSD), three types of pure biodiesels and their blends with ULSD. For ULSD, the contribution of pSVOCs to total particulate organic matter (POM) mass in the engine exhaust ranged between 21 and 85%. Evaporation of pSVOCs from the diesel particles during dilution led to decreases in the hydrogen to carbon ratio of POM and the PM number emission factor of the particles. Substituting biodiesels for ULSD could increase pSVOCs emissions but brought on large reductions in black carbon (BC) emissions. Among the biodiesels tested, tallow/used cooking oil (UCO) biodiesel showed advantages over soybean and canola biodiesels in terms of both pSVOCs and nonvolatile PM emissions. It is noteworthy that PM properties, such as particle size and BC mass fraction, differed substantially between emissions from conventional diesel and biodiesels.

The present study investigates the effect of the TiO2 nanofluid on the formation of hydrocarbon, carbon-monoxide, nitrogen oxide and smoke emission from a neat mustard oil methyl ester fueled diesel engine. TiO2 nano particle with an average size of 50 nm was synthesized by sol-gel route. The synthesized particles are dispersed with mustard oil methyl ester at various concentrations (100 and 200 ppm) by the means of a mechanical homogenizer and an ultrasonicator. Experiments were conducted in a four-stroke, single-cylinder, diesel-engine, fuelled with diesel, neat mustard oil methyl ester and nanofluid incorporated methyl ester. From the obtained results, it can be recognized that methyl ester from mustard oil is potential candidate as an alternative fuel in existing diesel engine. Further, it is also observed that TiO2 nanofluid associated to mustard oil methyl ester reduced various emissions over neat mustard oil methyl ester.

Economic and environmental stimuli for biodiesel production have also increased production of glycerol, a byproduct present in biodiesel industry wastewater (BIW). The objective of the present study was to analyze which factors influenced glycerol biodegradation in anaerobic sequencing batch reactors (AnSBR) in the attempt to optimize chemical oxygen demand (COD) removal efficiency. Six factors were analyzed: pH, temperature, mixing speed, influent COD, inoculum mass, and reaction time. The results indicated that mixing speed, temperature, mass of inoculum, and reaction time had direct influence on COD removal efficiency in BIW. The reactor used in the experiments operated with efficiencies and applied loads above those mentioned in the literature. The mathematical model generated in this study can be used for estimating efficiency, process control and scale up of AnSBR.

Treated wastewater (TWW) is an imperative nonconventional water resource for reuse in irrigation to cope with the water shortage and agricultural expansion in Egypt. The Bahr El-Baqar drain in Sharqia, Egypt, is one of the main drains in the Nile Delta that receives various types of wastewater. Monitoring and assessing the drain’s water quality were achieved by collecting georeferenced water samples along the drain during the 2015 summer and winter cropping seasons. Chemical, microbial, and parasitic analyses were performed. Additionally, surface soil samples irrigated with the drain water were gathered from the adjacent area to quantify the main physicochemical properties. Water analysis results revealed that the concentrations of most trace elements were within international standards and the Egyptian allowable levels for TWW reuse in agriculture. Oxygen depletion was observed for all samples collected. The microbial analysis indicated that there was fecal coliform contamination (>1000 per 100 mL) in the summer and winter samples. Concentrations of PO₄ and SO₄ were within the permissible level for irrigation use, whereas NH₄, NO₃, and MoO₄ concentrations were higher than the recommended values for reusing Bahr El-Baqar water in irrigation. Based on the soil analysis results, Cd contamination was observed, whereas the Pb concentration in soils was slightly higher than its normal range. Mixing Bahr El-Baqar water with freshwater and implementing appropriate on-farm treatment before the reuse are recommended as a prerequisite for reusing Bahr El-Baqar water for irrigation. Bio-diesel fuel and energy oil crops are recommended for the studied region.

Glycerol, considered as a waste feedstock resulting from biodiesel production, has received much attention in recent years due to its properties, which offer to recover energy. The aim of this study was to investigate the use of a thermal water vapor plasma for waste (crude) glycerol conversion to synthesis gas, or syngas (H₂ + CO). In parallel of crude glycerol, a pure glycerol (99.5%) was used as a reference material in order to compare the concentrations of the formed product gas. A direct current (DC) arc plasma torch stabilized by a mixture of argon/water vapor was utilized for the effective glycerol conversion to hydrogen-rich synthesis gas. It was found that after waste glycerol treatment, the main reaction products were gases with corresponding concentrations of H₂ 50.7%, CO 23.53%, CO₂ 11.45%, and CH₄ 3.82%, and traces of C₂H₂ and C₂H₆, which concentrations were below 0.5%. The comparable concentrations of the formed gas products were obtained after pure glycerol conversion—H₂ 46.4%, CO 26.25%, CO₂ 11.3%, and CH₄ 4.7%. The use of thermal water vapor plasma producing synthesis gas is an effective method to recover energy from both crude and pure glycerol. The performance of the glycerol conversion system was defined in terms of the produced gas yield, the carbon conversion efficiency, the cold gas efficiency, and the specific energy requirements.

Exploring new renewable energy sources as a substitute of petroleum reserves is necessary due to fulfilling the oncoming energy needs for industry and transportation systems. In this quest, a lot of research is going on to expose different kinds of new biodiesel sources. The non-edible oil from candlenut possesses the potential as a feedstock for biodiesel production. The present study aims to produce biodiesel from crude candlenut oil by using two-step transesterification process, and 10%, 20%, and 30% of biodiesel were mixed with diesel fuel as test blends for engine testing. Fourier transform infrared (FTIR) and gas chromatography (GC) were performed and analyzed to characterize the biodiesel. Also, the fuel properties of biodiesel and its blends were measured and compared with the specified standards. The thermal stability of the fuel blends was measured by thermogravimetric analysis (TGA) and differential scan calorimetry (DSC) analysis. Engine characteristics were measured in a Yanmar TF120M single cylinder direct injection (DI) diesel engine. Biodiesel produced from candlenut oil contained 15% free fatty acid (FFA), and two-step esterification and transesterification were used. FTIR and GC remarked the biodiesels’ existing functional groups and fatty acid methyl ester (FAME) composition. The thermal analysis of the biodiesel blends certified about the blends’ stability regarding thermal degradation, melting and crystallization temperature, oxidative temperature, and storage stability. The brake power (BP), brake specific fuel consumption (BSFC), and brake thermal efficiency (BTE) of the biodiesel blends decreased slightly with an increasing pattern of nitric oxide (NO) emission. However, the hydrocarbon (HC) and carbon monoxides (CO) of biodiesel blends were found decreased.

Because of the harmful effects of greenhouse gas (GHG) emitted by petroleum-based fuels, the adoption of alternative green fuels such as biodiesel and compressed natural gas (CNG) is an inevitable trend in the transportation sector. However, the transition to alternative fuel vehicle (AFV) fleets is not easy and, particularly at the beginning of the transition period, drivers may be forced to travel long distances to reach alternative fueling stations (AFSs). In this paper, the utilization of bi-fuel vehicles is proposed as an operational approach. We present a mathematical model to address vehicle routing problem (VRP) with bi-fuel vehicles and show that the utilization of bi-fuel vehicles can lead to a significant reduction in GHG emissions. Moreover, a simulated annealing algorithm is adopted to solve large instances of this problem. The performance of the proposed algorithm is evaluated on some random instances.

Oleaginous microorganisms such as microalgae, yeasts, bacteria and filamentous fungi are alternative sources of vegetal or animal fats for biodiesel production. This research evaluated the lipid production by the biomass Trichoderma koningiopsis MX1 with a non-stirring culture at room temperature, and fungal lipids were extracted through three techniques for biodiesel generation purposes. The three modified lipid extraction techniques yielded 18.4, 10.3 and 17.1 % of fungal lipids. The trans-esterification of lipids indicated that the controlling components for biodiesel were palmitic (40.8 %) and linoleic acids (ranging from 37.6 % to 41.2 %). Results show that fungal cultural conditions and the lipid extraction technique are determinants for producing biodiesel from fungal lipids. Therefore, the modification of some of these conditions could increase their efficiency and viability.

The depletion of fossil fuels and hike in crude oil prices were some of the main reasons to explore new alternatives from renewable source of energy. This work presents the impact of various bowl geometries on diesel engine with diesel and biodiesel samples. Three non-edible oils were selected, namely pumpkin seed oil, orange oil and neem oil. These oils were converted into respective biodiesel using transesterification process in the presence of catalyst and alcohol. After transesterification process, the oils were termed as pumpkin seed oil methyl ester (PSOME), orange oil methyl ester (OME) and neem oil methyl ester (NOME), respectively. The engine used for experimentation was a single-cylinder four-stroke water-cooled direct-injection diesel engine and loads were applied to the engine using eddy current dynamometer. Two bowl geometries were developed, namely toroidal combustion chamber (TCC) and trapezoidal combustion chamber (TRCC). Also, the engine was inbuilt with hemispherical combustion chamber (HCC). The base line readings were recorded using neat diesel fuel with HCC for various loads. Followed by 20% of biodiesel mixed with 80% neat diesel for all prepared methyl esters and termed as B1 (20% PSOME with 80% diesel), B2 (20% OME with 80% diesel) and B3 (20% NOME with 80% diesel). All fuel samples were tested in HCC, TCC and TRCC bowl geometries under standard injection timing and with compression ratio of 18. Increased brake thermal efficiency and reduced brake specific fuel consumption were observed with diesel in TCC geometry. Also, higher heat release and cylinder pressures with lower ignition delay were recorded with TCC bowl geometry. TCC bowl geometry showed lower CO, HC and smoke emissions with B2 fuel sample than diesel and other biodiesel samples. But, higher NOx emission was observed in HCC and TCC than that in TRCC bowl geometry. Graphical abstract ᅟ