Emission and performance analysis of diesel engine running with CeO2 nanoparticle additive blended into castor oil biodiesel as a substitute fuel.

The implications of adding cerium oxide (CeO2) nanoparticles as a fuel additive to a castor oil biodiesel-diesel fuel blend on engine performance and emissions in a single-cylinder four-stroke diesel engine under various speed were examined in the current study. The test fuels used were fossil diesel fuels, B5 blend biodiesel (as 5% biodiesel and 95% diesel), B10 blend biodiesel (as 10% biodiesel and 90% diesel), B15 blend biodiesel (as 15% biodiesel and 85% diesel), B20 blend biodiesel (as 20% biodiesel and 80% diesel), and B25 blend biodiesel (as 25% biodiesel and 75% diesel), with cerium oxide (CeO2) nanoparticle additive (75 ppm). The result of the physio-chemical properties of the oil samples was within the limit of the ASTM standard. The addition of CeO2 nano additive to the biodiesel-diesel blends has demonstrated a significant reduction in emission and increased in engine performance for all biodiesel-diesel blends for the engine operating speed range. From the result B25 have the maximum reduction rate in BSFC and B10 have the minimum reduction rate in BSFC. The average maximum increment of thermal efficiency was 22.2% for B10 with CeO2 inclusion. CO emission increased as engine speed increased. HC emission was reduced for all blend, with and without CeO2 nano additions as speed increased. Maximum NOx emission was seen at the rated speed of 2700 rpm without nano additive and at 2900 rpm with nano additive. CeO2 nano additive reduced the soot opacity by 11.56% for all biodiesel-diesel blends for the engine operating speed range. As the objective of this study the results indicates CeO2 nano additive reduced emissions and improved the performance. So, using sustainable biodiesel-diesel blends made from castor oil with CeO2 nano additive advisable in ideal operating conditions for diesel engines.

Numerical modeling and CFD simulation of diffuser augmented dual vertical axis hydrokinetic Banki-Michell turbine.

Hydrokinetic Banki turbines present an affordable, technically feasible, environmentally friendly technology. Their construction without requiring more expensive structures like diversion weirs, canals, forebay, and penstock, makes their initial investment much lower than commonly used horizontal Banki turbine of the same capacity. The possibility to install in the existing canals for Ultra Low Head applications is the additional motivating factor for this research. The system studied includes two Banki runners without internal shafts mounted vertically side by side surrounded by nozzle and diffuser structures. In the first scenario, Nozzle and then the Nozzle-diffuser augmented structures were separately studied to enhance the output of the runner for ultra-low head application, and the effects of each on the speed, pressure, and power output were analyzed. For the case of commonly used Banki, without nozzle and diffuser augmentation the speed for Ultra Low Head was minimum and determined to be 344 rpm, which is far below the recommended value of 800 rpm for safe operation at a flow rate of 1 m^3/s. In view of this, in the present study the enhanced speed on account of improvement was found to be 850 rpm and 1025 rpm for the design without and with diffuser assemblies respectively. Besides, the performance is seen to be improved by 7.6% with the diffuser as compared with the one without diffuser assembly. Detailed simulation results are presented and discussed: 3D ANSYS-FLUENT optimization result provided optimum number of blades for each runner to be 19 and with the optimum throat width in both cases as 202 mm. On account of the lack of any results reported so far for this innovative geometry, validation of the simulated results was carried out with reported results for the dual horizontal axis Banki turbines with good agreement.

Production, optimization, and characterization of Ethiopian variant Prosopis juliflora based biodiesel.

Considering the need for biodiesel production from non-edible oil sources and taking into account the fact that Prosopis Juliflora (JF) is identified as a highly invasive species in Ethiopia, this research focuses on biodiesel production from a possible and promising alternative feedstock. The objective of this study is to analyze Ethiopian variant Juliflora based biodiesel (JFB) production through transesterification, carry out optimization by exploring the effects of various process parameters and characterization of functional groups (with GC-MS,FT-IR and NMR) including rheological behavior, not yet been reported earlier. As per ASTM protocol testing, the methyl ester of Juliflora has been found to have the following main fuel properties: kinematic viscosity (mm2/s) 3.395, cetane number 52.9, acid number (mgkoh/g) 0.28, density (gm/ml) 0.880, calorific value (MJ/kg) 44.4, methyl ester content (%) 99.8, and flashpoint (°C) 128, copper strip corrosion value 1a,%FFA (free fatty acid) 0.14. When compared with those of diesel, the viscosity, density, and flash point of JFB are seen to be higher than those of diesel, although it has a similar calorific value but more importantly higher than most of the other biodiesels. Based on an assessment using response surface methodology, methanol concentration together with catalyst loading, temperature, and reaction time are determined to be the most important influencing process parameters. The best molar ratio for methanolysis was observed to be 6:1 with a catalyst concentration of 0.5 wt% at 55 °C for 60 min for biodiesel yield at 65%. The JFB maximum yield of 130 ml at 70 min and the minimum yield of 40 ml at 10 min demonstrate that as mixing time increases, JFB yield tend to increase up to a certain time limit. The maximum raw oil yield rom crushed seed with hexane solvent was observed to be 480 ml within 3 days from 2.5 kg of crushed seed. The Fourier transform infrared analysis (FT-IR) revealed the presence of all desired functional groups necessary for biodiesel on OH radicals at wave numbers of 3314.40 cm-1, Aliphatic methyl C-H at 2942.48 cm- 1 with a functional group (CH-3-,-CH2-), and methylene C-H at 2832.59 cm-1. The gas chromatography-mass spectrometer (GC-MS) study confirmed the higher ester content present in the JFB with a higher unsaturation level of 68.81%. The fatty acid, oleic acid has a lower saturation level of 4.5%, while palmitic acid has a lower threshold level of 2.08%. The Rheometer test showed that shear stress and viscosity reduced with increasing temperature within the range of biodiesel requirements, and the Newtonian behavior was confirmed. The JFB has a fairly high viscosity and shear rate at low temperatures. The 1H NMR (nuclear magnetic resonance) study established that JFB has a necessary ingredient; and aliphatic resonances occur in the chemical shift region of 1.5-3.0 ppm. Significant regions indicate protons bound to heteroaromatics, aldehydes, as shown by 13C NMR spectrum. The findings from the FT-IR, GC-MS, 1H NMR, and 13C NMR are in agreement thus validating the presence of numerous functional groups in JFB as such. Since JFB possesses the requisite biodiesel fuel attributes, Prosopis Juliflora need to be pursued as a promising biodiesel feedstock in Ethiopia for alleviating the burden of imported fuels while also addressing difficulties with emissions released by the combustion of fossil fuels.

Optimization of soluble phosphate and IAA production using response surface methodology and ANN approach.

Phosphorus (P) is often found inaccessible to plants, as it forms precipitates with cations and can be converted to accessible forms by using Phosphate solubilizing bacteria (PSB). In the present study, isolation and characterization of PSB from rhizospheric soil of coffee plants were performed. The influence of four independent variables (incubation temperature, incubation time, pH, and inoculum size) was investigated and optimized using an artificial neural network and response surface methodology on the solubility of phosphate and indole acetic acid production. The bacterium that can dissolve phosphate were isolated in Pikovskaya's agar containing insoluble tricalcium phosphate. Total, six Phosphate Solubilizing Bacteria were isolated and three of them (PSB1, PSB3, and PSB4) were found to be effectively solubilizing phosphate. Based on phosphate solubilizing index results Pseudomonas bacteria (PSB1) was selected for modeling. The results showed that both models performed reasonably well, but properly trained artificial neural networks have the more powerful modeling capability compared to the response surface method. The optimum conditions were found to be incubation temperature of 37.5 °C, incubation time of 9 days, pH of 7.2, and inoculum size of 1.89 OD. Under these conditions, the model predicted solubility of phosphate of 260.69 µg/ml and production of IAA of 80.00 µg/ml with a desirability value of 0.947. In general, the isolated Pseudomonas is expected to have phosphorus-degrading ability that promotes plant growth, and further field experimental work is required to use this bacterial strain as biofertilizer, as an alternative to synthetic fertilizer.

Transient performance prediction of solar dish concentrator integrated with stirling and TEG for small scale irrigation system: A case of Ethiopia.

The global population growth, climate change effects, and the rapid decline in the stock of fossil fuels increase the demand for food, water, and energy. Irrigation technologies are essential in negating poverty and food insecurity in a developing country while promoting sustainable development goals. However, rain-fed agricultural activities and the lack of modern irrigation technologies in Ethiopia aggravate the problem. This work presents a transient performance investigation of a solar dish concentrator coupled with a Stirling engine and thermoelectric generator for the small-scale irrigation system. A solar dish concentrator with a 2.8 m aperture diameter and 0.4 m depth was used, and Stirling engine analysis was performed using a second-order adiabatic model. System performance was investigated at different operating parameters to predict output power and pump flow rate variation with solar time for a selected irrigation season. Results show that at a heat source temperature of 413.8 K, the thermoelectric unit gives maximum electrical power of 5.2 W at an efficiency of 2.78%. At the same time, the Stirling engine-driven pump provides a cumulative flow rate of 173,594.95 L per day at a thermal efficiency of 18.61%. The output power and pump flow rate reach their maximum at noontime for all selected irrigation seasons. The effect of regenerator effectiveness on the thermal efficiency of the Stirling engine was also examined, and the findings indicate that the Stirling engine's thermal efficiency rises with regenerator effectiveness. Using a solar thermal irrigation system in a location with a high solar radiation potential allows small farmers to generate more income and contribute to the country's food security.

Modeling and Optimization of Biodiesel Production from Croton macrostachyus Leaves Oil.

The biodiesel produced from Croton macrostachyus (CM) leaves mostly contains unsaturated fatty acid esters with low stability of oxidation. A Croton macrostachyus (CM) leaf, a non-edible resource, was utilized to produce biodiesel. This novel work focuses on the trans-esterification of species known as CM leaves oil to produce biodiesel with the help of CaO nanoparticle (CaO NPs)-catalyzed technique. The esterification process is optimized utilizing response surface methodology (RSM) based on central composite design (CCD). Four parameters that affect the production of biodiesel from Croton macrostachyus (CM) leaves oil have been examined. The optimum operating conditions for the selected four factors have been investigated as reaction time 25.95 min, temperature 63.325 °C, methanol to oil ratio 28.093:1 in mg/L, and catalyst concentration 3.001%wt with a desirability value of 1. Under the predicted parameters, to optimize the production of biodiesel, the quadratic mathematical models were developed. The optimized trans-esterification result showed that a 96.375% yield of biodiesel (FAME) was found. Three different experimental runs were carried out to validate the proposed model by using the optimized process parameters, and 95.818% (average) of experimental yield have been found. The CM leaves oil biodiesel physicochemical properties were obtained, and it was observed all the tasted properties agree with fuel specifications set by ASTM D6751 standards. In conclusion, this work formulates the baseline and the need for future exploration of CM leaves oil for biodiesel production through different methods.

Numerical study of different shape design of piston bowl for diesel engine combustion in a light duty single-cylinder engine.

Diesel engine is the prime mover on land transportation industry and used in a variety of power generation applications due to their higher fuel efficiency. However, the engine research community faces a major hurdle rigorous restriction introduced in the Glob to reduce pollutant emissions from internal combustion engines. Different piston bowl shape designs allows more precise mixing before combustion to enhance in the optimization using computational calculations to reduce emissions. The investigation was to reduce the NOx and PM emissions using combustion simulation comparing with each piston of a single-cylinder engine at a CR of 24, 4-stroke, and water-cooled Engine. The four piston bowl shapes of DSEVL2 BMW M47T, Shallow Hesselman, Lombardini 15LD350, and DOOSANP158FE were analyzed by the Diesel-RK combustion simulation. After successful validating; the simulation model shows that the peak cylinder pressure of Piston-2 is 131bar and the peak cylinder pressure of Piston-4 is 113bar. The Maximum Cylinder Temperature of the Piston-2 is 2048.2k, and the lowest value of Cylinder Temperature of the Piston-4 is 1680.9k the cylinder temperature of Piston-2 is 18% higher than Cylinder Temperature of Piston-4. The simulation result indicates that the temperature is within the acceptable limit in between 1400-2000k except for the piston temperature of 2048.2k. The PHRR of the Piston-3 is 0.082 with great variation in between maximum and minimum due to the presence of pre-and post-injection, the HRR-P4 is 0.035 J/°CA with the single injections. The HRR of the Piston-3 is the highest while HRR of the Piston-4 lowest with 39%. The NOx in the exhaust gas is 25.62 in the NOx piston-1; 16 in NOx of Piston-2, 18.2 in NOx-P3, and NOx-P4 is 12.74 g/kWh respectively. The NOx of the NOx-P2 is lower than first and second piston due to the lower fuel fraction of NWF dilution outer the sleeve, low fuel fraction in core of the free spray, low fuel fraction in fronts of the free spray, low fuel fraction in the core of the fuel free spray. The Particulate Matter emission in PM-P1 is 0.35, and PM-P2 is 0.43 â€‹g/kWh which is higher than all the other. Although there is a substantial decrease in PM, a penalty in NOx is observed for PM-P1 but PM of the P2 is higher after the peak result of emission.

Alkaline hydrogen peroxide pretreatment of cladodes of cactus (opuntia ficus-indica) for biogas production.

The alkaline hydrogen peroxide (AHP) pretreatment of cladodes of cactus (Opuntia ficus-indica) for biogas production was evaluated based on the delignification of cladodes of cactus. The effects of alkaline hydrogen peroxide concentration (30% w/w solution) and the pretreatment time (3, 6, 9, and 12 h) were evaluated at pH 11.5, temperature of 30 °C, and 180 rpm for removal of lignin. A batch of anaerobic digestion experiments were conducted at mesophilic temperature conditions (37 ± 1 °C) with the pretreated biomass. The feed stock (cladodes of cactus) used in this study contained 12.51 ± 1.25 cellulose, 16.34 ± 2.93% hemicellulose, and 10.45 ± 2.31% lignin, and the balance were (carbohydrate, protein, lipid, and ash). After AHP pretreatment, the lignocellulosic content of the feed stock was changed to 12.50 ± 1.84%, 13.63 ± 3.23%, and 7.49 ± 3.05% for cellulose, hemicellulose, and lignin respectively. The AHP pretreatment of cladodes of cactus highly affected the lignin structure relative to cellulose and hemicellulose. The alkaline hydrogen peroxide pretreatment resulted in a higher amount of biogas produced from 877.9 ± 15.12 ml biogas/g VS to 1613.5 ± 10.76 ml biogas/g VS which is an 83.4% increment and decreased after 9 h treatment to 1398.8 ± 17.8 ml biogas/g VS. In addition, the measured methane yields range from 302.48 ± 0.33 to 602.65 ± 3.24 ml CH4/g VS. The results showed that alkaline hydrogen peroxide pretreatment of cladodes of cactus is an effective strategy for enhance biogas yield.