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Biodiesel is a biomass fuel that can replace petroleum diesel fuel. One of the advantages of biodiesel fuel as renewable energy source that it is more environmentally friendly than fossil fuels because biodiesel significantly reduces greenhouse gas emissions compared to fossil fuels. FAME (fatty acid methyl ester) is a derivative product of CPO (crude palm oil) that has been treated both physically and chemically. The main advantage of FAME lies in the low content of impurities, especially sulphure and metal content. FAME comes from vegetable oil raw materials, which contain high enough fatty acids, around 61-62%, and nowadays, it is used as a mixture with petroleum diesel. The characteristics of biodiesel obtained from the conversion of FAME into biodiesel by pyrolysis at a temperature range of 160 – 200 oC indicate that the biodiesel produced is density 0.8475 kg/m3, viscosity 3.053 cSt, calculated cetane index (CCI) 48.5, flash point 59oC, moisture content 223 ppm, and sulphure content of 0.07% m/m. The results obtained are below the maximum limit of the specified biodiesel quality requirements.

Petroleum refining generates hazardous sludge with polyaromatic hydrocarbons and heavy metals. The main objective of the study was to evaluate the performance of microwave pyrolysis for the recovery of oil from furnace oil sludge. The characteristics of furnace oil tank bottom sludge such as pH, moisture, viscosity, and volatile hydrocarbon content were determined. Thermal Gravimetric Analysis has been done to determine the cracking and degradation range of oily sludge. Gas Chromatography-Mass Spectrometry was used to fingerprint the hydrocarbon. Pyrolysis experiments were conducted in lab-scale pyrolysis set up with different susceptors and sludge in a specific weight ratio. The process parameters like microwave power, sludge: susceptor ratio were optimized to increase the oil yield. Graphite mixed sludge in 1:5 ratio at 450 W power shown higher oil yield. The calorific value of oil and char were determined as 44,442.9 and 16,686.58 kJ /kg. Physicochemical characteristics of oil such as flash point, density, and kinematic viscosity are 94 °C, 874.9, kg/m3, and 4.063 cSt. Cetane index and sulfur content were measured as 40.9, 6.85 g/kg respectively. The gas analysis had shown the presence of H2, CO2, CO, and CH4 compounds. Char contains a higher percentage of carbon, Fe, Al, Ni, Pb, Cd, and S compounds.

The authors conducted droplet evaporation experiments of light cycle oil (LCO) at various ambient temperatures and pressures. Five kinds of LCO and three kinds of arranged fuels were used. We investigated the evaporation characteristics of LCO and the relationships between the evaporation characteristics and the cetane index. In addition to that, a surrogate fuel composed of four chemical species, which can simulate the droplet evaporation characteristics of LCO, was suggested. Experimental results show that the differences in droplet lifetime between fuel species become larger with decreasing ambient temperature. This is because the low volatile component made the evaporation rate outstandingly slow at a low ambient temperature. It was found that the relationship between droplet lifetime and the late-stage distillation temperature becomes stronger at low ambient temperature and high ambient pressure. By an analysis employing the properties of chemical species in LCO surrogate fuel, it is clarified that the mass evaporation rate becomes smaller than the internal diffusion, which is the condition similar to that in the distillation test. Finally, the relationship between the droplet lifetime and the cetane index was investigated. It can be concluded that the droplet lifetime is independent of the cetane index under all conditions tested in this study. The experimental data obtained by this research can be utilized for the validation of multicomponent fuel droplet evaporation models in the future.

In the present study, production of biodiesel from biomass containing free fatty acids has been evaluated through electrolysis method as a novel efficient technique, in absence and presence of alkaline and acidic catalysts at mild operating condition. The impact of operating parameters such as voltage (10−30 V/cm), reaction time (1−3 h), methanol to oil molar ratio (10:1−40:1), acetone to methanol molar ratio (0:1−0.5:1), NaCl concentration (0−0.045 M) and catalyst type and loading on the process performance have been investigated in term of biodiesel production yield. The achieved results indicate that the biodiesel production yield using electrolysis method is about 42 % at voltage of 20 V/cm, reaction time of 2 h, NaCl concentration of 0.015 M, methanol to oil molar ratio of 20:1, acetone to methanol molar ratio of 0.25:1 and without presence of catalyst, whereas it is improved to 52 % and 95 % in the presence of 5.6 wt.% of KOH and 13 wt.% of H2SO4 as catalyst, respectively. The determined physicochemical properties of the synthesized biodiesel via electrolysis method incorporating density, kinematic viscosity, cetane index, Iodine value and cloud point properties satisfy the main fuel standard criteria. The cetane index of synthesized biodiesel using electrolysis method is 57.3.

Due to depleting fossil fuel sources, plastic-derived fuel oil (PDFO) has received much attention over the past decade as an alternative to conventional diesel oil. Although several researchers have reported the properties of PDFO and recommended its usage in diesel engines, no study has thoroughly compared it with conventional diesel oil. This study aims at comparing PDFO produced from pyrolysis of waste plastic (LDPE, HDPE, PS, and PP) with conventional diesel oil based on a number of quality parameters and energy recovery potential. The quality parameters of color and appearance, water content, density, viscosity, volatility, copper strip corrosion, flash point, pour point, and energy content, as well as the cetane index of the fuels, were assessed following ASTM standards. The obtained results indicated no significant difference between the water contents and densities of the fuel oils. Pensky–Martens Closed Cup (PMCC) flash point for PDFO was significantly lower than that of conventional diesel oil. Although the pour points and viscosities of PDFO were significantly different from conventional diesel oil, the values were within the recommended range. All the PDFO types had higher volatilities than conventional diesel oil in the lighter section of the distillation curve, whereas no significant difference was detected in the heavier section. On the ASTM corrosion chart, conventional diesel oil belongs to class 1a, whereas all the PDFO types belong to class 2a. Energy recovery calculations revealed that PDFO has the potential to produce energy equivalent to 203,000 barrels of oil. It can be concluded that although PDFO has undesirable high volatility in the lighter section of the distillation curve and relatively low flash point, it compares relatively well with conventional diesel oil and thus is a potential substitute.

Operating combined cycle gas turbines and/or low speed diesel engines on light petroleum crudes rather than distillate or heavy fuels produced from them avoids the carbon emissions associated with refining while continuing to achieve high energy conversion efficiencies. However, crude assays generated for refinery feed stock characterization do not include an ignition propensity property indicator, and the wide distillation range of crudes disfavors the use of the Calculated Carbon Aromaticity Index or Cetane Index used to characterize heavy or distillate fuel ignition quality. Here, the derived cetane number (DCN) of a single (whole) light crude is reported and the liquid volume fractions and DCNs of light end distillation fractions of this and three other light crudes are compared. Using ASTM D86 distillation method, four crudes were distilled into four light fractions as typically reported in crude assays: 1) light naphtha; 2) heavy naphtha; 3) kerosene; 4) light gas oil. DCNs were obtained using an ignition quality tester (IQT) and ASTM D6890 procedures. The DCNs of the fractions 1) – 4) for all crudes increased from 23 to 35 for the lowest boiling point fraction to 50–60 for the highest tested, in the range of the DCN measured for one of the whole crudes (52.6). The large DCN variation with distillation temperature suggests that preferential vaporization is likely relevant to pre-vaporized/premixed gas turbine combustion behaviors near operational limits. 1H and 13C NMR spectra were also acquired for the distilled samples. A QSPR regression developed using a Scheffe simplex-polynomial descriptor indicates that n-paraffinic CH2 groups play the most significant role in determining crude global ignition propensity. Results suggest that the reactivity potential of crude oils can be estimated reasonably well by employing a well-trained QSPR prediction tool for DCN, based upon key chemical functional groups determined from 1H and 13C NMR spectral analyses.

Energy has always been an important part of society development. The traditional method of harnessing energy from fossil resources has proved to be not sustainable and environmentally disastrous. The energy crisis augmented with baffled economy affecting many poor and developing countries. However, with technology the difficulty has been brought to a safe level day by day. Researchers have been keen on developing several sustainable energy resources for meeting the required energy demand by reducing pressure on fossil fuel. This solves two main issues: first, it decreases the environmental pollution as burning of fossil resources leads to the emanation of harmful pollutants to the atmosphere and second, it preserves the fossil resources for future generation. Biofuel is part of such kind of development. In this study, Neem oil is selected for biodiesel preparation. Neem biodiesel is prepared from Neem seed oil using sodium hydroxide as base catalyst. The molar ratio of oil to alcohol, catalyst amount, reaction speed, temperature and time has been optimized and finally, the fuel properties are also evaluated as per ASTM standards. With optimal settings maximum yield found to be 96%. The acid value contained within 0.09 mg KOH/g and cetane number found to be 52, which is more than diesel cetane index.

Resumen Introducción. Jatropha curcas L. (JC), es una especie multipropósito con aplicaciones biológicas, farmacológicas e industriales. Su aceite es reconocido por la composición dominante de los ácidos grasos oleico-linoleico que lo hacen apto como biodiésel en motores de combustión interna, sin hacer cambios importantes al diseño del motor. Objetivo. Identificar en el aceite de cinco genotipos de JC en Colombia los índices de cetano, peróxido, yodo, el valor de acidez, el poder calorífico y verificar si cumplen con las normas para producción de biodiésel. Materiales y métodos. Se realizó un experimento en Espinal, Colombia, en un diseño de bloques completos al azar con cinco tratamientos y tres repeticiones. Los tratamientos estuvieron constituidos por cinco genotipos de JC. Se utilizó el fruto de la quinta cosecha en el año 2015. Del aceite se determinaron cinco ácidos grasos (oleico, linoleico, linolénico, palmítico y esteárico) y cinco factores químicos (índices de cetano, peróxido y yodo, acidez y poder calorífico). Resultados. El aceite de los cinco genotipos de JC evaluados en Colombia presentaron un perfil lipídico con predominancia de los ácidos grasos monoinsaturados (oleico C18:1) y poliinsaturados (linoleico C18:2). Los genotipos de JC evaluados en Colombia presentaron bajos índices de cetano, peróxido y yodo, baja acidez y alto poder calorífico. Conclusiones. Las propiedades de índices de cetano, peróxido y yodo, acidez y poder calorífico en los genotipos evaluados, cumplieron con las especificaciones de la Sociedad Americana de Ensayos y Materiales (ASTM) y de la europea (EN 14214), por lo que se catalogan como materia prima apropiada para la producción de biodiésel. Abstract Introduction. Jatropha curcas L. (JC) is a multipurpose species with biological, pharmacological, and industrial applications. Its oil is recognized by the dominant composition of oleic-linoleic fatty acids that make it suitable as biofuel in internal combustion engines, without making major changes to the engine design. Objective. To identify in the oil of five JC genotypes in Colombia the cetane, peroxide, iodine, the acidity value, the calorific value indixes and to verify if they comply with standards for biodiesel production. Materials and methods. An experiment was carried out in Espinal, Colombia, in a randomized complete block design with five treatments and three repetitions. The treatments consisted of five JC genotypes. The fruit from the fifth harvest in 2015 was used. Five fatty acids (oleic, linoleic, linolenic, palmitic, and stearic) and five chemical properties (cetane index, acidity, peroxide, iodine, and calorific value) were determined from the oil. Results. The oil from the five JC genotypes evaluated in Colombia presented a lipid profile with a predominance of monounsaturated (oleic C18: 1) and polyunsaturated (linoleic C18: 2) fatty acids. The JC genotypes evaluated in Colombia presented a low cetane, peroxide, and iodine indexes, low acidity, and high calorific value. Conclusions. The properties of cetane and iodine indexes, of the genotypes evaluated complied with the specifications of the American Society for Testing and Materials (ASTM) and the European Norm for biofuel production, so they are classified as appropriate raw material for biofuel production.

Jatropha curcas is a highly toxic plant that produces seed containing viscous oil with productivity (2 ton/ha), it grows in tropical and sub-tropical regions and offer greater adaptability to a wide range of climatic and soil conditions. Its oils have been noted as an important alternative to produce green diesel via deoxygenation reaction. This study, deoxygenation of jatropha curcas oil (JCO) was carried out over NiO–Fe2O3 and NiO–ZnO catalysts that supported onto multi-walled carbon nanotube (MWCNT). It had found that high Fe and Zn dosages were ineffective in deoxygenation and greatest activity was observed on NiO(20) Fe2O3(5)/MWCNT catalyst. Structure-activity correlations revealed that low metal loading, large density of weak + medium acidic sites and strong basic sites play key role in enhancing the catalytic activities and n-(C15+C17) selectivity. Comparing carbon nanostructures and carbon micron size supported NiO-Fe2O3 revealed that green diesel obtained from NiO–Fe2O3/MWCNT catalysed deoxygenation had the highest heating value and the lowest amounts of oxygen content. Thereby, it confirmed the importance of carbon nanostructure as the catalyst support in improving the diesel quality. Considering the high reusability of NiO-Fe2O3/MWCNT (6 consecutive runs) and superior green diesel properties (flash point, cloud properties and cetane index) demonstrated the NiO–Fe2O3/MWCNT catalyst offers great option in producing excellent properties of green diesel for energy sector.

Recent developments in internal combustion engines have heightened the need for alternative biofuel. In the last five years, acetone-butanol-ethanol (ABE) has been extensively studied as a promisin...

The standard method (ISO 4264) for determining the cetane index of hydrogenated gas oil is time-consuming and expensive for routine laboratory tests. Conversely, near infrared (NIR) and Raman spectroscopies are high-speed and cost-effective techniques. In this study, these tools were used to create two models for the determination of the hydrogenated gas oil cetane index. First, ISO 4264 was used to measure the cetane index for 45 real samples used as calibration standards. Then, to create the models, the same samples were measured using NIR and Raman spectroscopies. The model values were then correlated against the ISO values. The Raman model predicted cetane index values with a maximum absolute difference of 1.2 from the ISO, while the NIR model showed a difference of 0.3. Finally, 10 additional real samples were used as validation standards to compare the models. The NIR model predicted values with better cross-validation error and lower absolute differences (NIR 0.334, Raman 0.654) from the ISO values compared to the Raman model. Thus, the NIR model is a fast and accurate method that can partially substitute for ISO 4264 when performing routine laboratory tasks.

A Corporeal chattels of hydrocarbon fuel have been conversed with constraint like density, kinematic viscosity, flash point, pour point, aniline point, rams bottom carbon, total acidity, cetane index and distillation. The consequence of these chattels gives the evidence about the excellence dissimilarity. The dissimilarity of the constraint gives appreciated significance of the hydrocarbon fuel and the nature of hydrocarbon (carbon 12 to carbon 22). flash point and pour point support the dissimilarity of hydrocarbon fuel. The findings and the deviations of data are examined, isolated and conveyed.

A rapid increase in the use of non-biodegradable plastics and their disposal after use has had a detrimental impact on the environment. Used plastics (used low-density polyethylene – ULDP) were selected as feedstock for the extraction of pyrolytic oil. The pyrolysis process was carried out in a semi-batch reactor with a silica alumina catalyst in the existence of fluidizing gas N2 in a reactor at 500 °C for 60 min. The maximum liquid, gas, and char yields were 93.5 wt%, 5.4 wt%, and 1.1 wt%, respectively. Experimental analysis was carried out to obtain their functional and structural groups by FT-IR and the carbon distribution was identified by GC-MS analysis. The blends of 20%, 40%, 60%, 80%, and 100% on a volume basis were chosen for the detailed study. For the pyrolytic blends, the combustion, performance, and emission characteristics were tested at different engine loads. During combustion, the heat release rate was extremely high for neat ULDP oil because of the high energy content and a higher cetane index. The efficiency of ULDP20 was higher than in other blends, whereas NOx and smoke emissions of ULDP20 were lower among the blends but higher than diesel. ULDP20 performed similarly as diesel. Hence, ULDP20 is recommended as a fuel for the diesel engine.

Compression ignition engines powered by diesel are the work horses of developing countries like India. However, burning fossil fuel causes a lot of air pollution and the depletion of fuel at an alarming rate. Fuels produced from biomass or wastes can partially substitute fossil diesel to decrease its consumption. One such feedstock is waste cooking oil (WCO) which can be easily converted into fuel for diesel engines. The hydrotreating process stands out among the methods available for converting WCO into fuel, since its properties are almost similar to fossil diesel with little or no oxygen content. In this study, the physico-chemical properties of the hydrotreated waste cooking oil (HVO), biodiesel of waste cooking oil, diesel and blends of HVO and diesel are compared. The blends were prepared by mixing 10%, 20%, 30%, 40% and 50% of HVO on volume basis in diesel. The evaporation rate and ignition probability of the fuel samples were found by using a hot-plate test setup. HVO had higher ignition probability than all the test sample. As the percentage of HVO increased in the test samples, the ignition probability increased. The Sauter mean diameter (SMD) of the samples was also found using Malvern Spraytec. The SMD of HVO was larger than diesel but smaller than biodiesel. The study shows that blends of HVO up to 30% are feasible for present use in diesel engines, as the viscosity (2.54, 2.59 and 2.62cSt) and calorific value (42.41, 42.29, 42.08 MJ/kg) of the three blends (10%, 20% and 30%) is close to diesel (2.51cSt and 42.58 MJ/kg). Also, due to high cetane index, neat HVO or blends having higher HVO content (> 30%) cannot be used in the existing engines as the engine power output may be affected. Therefore, to use these fuels, the engine needs to be modified which is not feasible for existing engines. The FTIR and GC-MS analysis shows that the HVO has low oxygen content and high amount of paraffins, whereas biodiesel of waste cooking oil has high unsaturation and high oxygen content.

In this paper, the fuel properties of mixtures of diesel fuel and ethanol and diesel fuel and butanol in the ratio of 2.5% to 30% were investigated. The physicochemical properties of the blends such as the cetane number, cetane index, density, flash point, kinematic viscosity, lubricity, CFPP, and distillation characteristics were measured, and the effect on fuel properties was evaluated. These properties were compared with the current EN 590+A1 standard to evaluate the suitability of the blends for use in unmodified engines. The alcohols were found to be a suitable bio-component diesel fuel additive. For most physicochemical properties, butanol was found to have more suitable properties than ethanol when used in diesel engines. The results show that for some properties, a butanol–diesel fuel mixture can be mixed up to a ratio of 15%. Other properties would meet the standard by a suitable choice of base diesel.

The aim of the article is to determine the properties of fuel mixtures of Fischer–Tropsch naphtha fraction with traditional gasoline (petrol) to be able to integrate the production of advanced alternative fuel based on Fischer–Tropsch synthesis into existing fuel markets. The density, octane number, vapor pressure, cloud point, water content, sulphur content, refractive index, ASTM color, heat of combustion, and fuel composition were measured using the gas chromatography method PIONA. It was found that fuel properties of Fischer–Tropsch naphtha fraction is not much comparable to conventional gasoline (petrol) due to the high n-alkane content. This research work recommends the creation of a low-percentage mixture of 3 vol.% of FT naphtha fraction with traditional gasoline to minimize negative effects—similar to the current legislative limit of 5 vol.% of bioethanol in E5 gasoline. FT naphtha fraction as a biocomponent does not contain sulphur or polyaromatic hydrocarbons nor benzene. Waste materials can be processed by FT synthesis. Fischer–Tropsch synthesis can be considered a universal fuel—the naphtha fraction cut can be declared as a biocomponent for gasoline fuel without any further necessary catalytic upgrading.

Utilising pyrolysis as a waste tyre processing technology has various economic and social advantages, along with the fact that it is an effective conversion method. Despite extensive research and a notable likelihood of success, this technology has not yet seen implementation in industrial and commercial settings. In this review, over 100 recent publications are reviewed and summarised to give attention to the current state of global tyre waste management, pyrolysis technology, and plastic waste conversion into liquid fuel. The study also investigated the suitability of pyrolysis oil for use in diesel engines and provided the results on diesel engine performance and emission characteristics. Most studies show that discarded tyres can yield 40–60% liquid oil with a calorific value of more than 40 MJ/kg, indicating that they are appropriate for direct use as boiler and furnace fuel. It has a low cetane index, as well as high viscosity, density, and aromatic content. According to diesel engine performance and emission studies, the power output and combustion efficiency of tyre pyrolysis oil are equivalent to diesel fuel, but engine emissions (NOX, CO, CO, SOX, and HC) are significantly greater in most circumstances. These findings indicate that tyre pyrolysis oil is not suitable for direct use in commercial automobile engines, but it can be utilised as a fuel additive or combined with other fuels.

In this experimental study, pine oil is identified as low viscous low cetane (LVLC) fuel for compression ignition engine replacing diesel. Numerous advantages of LVLC fuels include improved combustion due to favorable physical properties than diesel. This leads to reduced hydrocarbon, smoke and carbon monoxide emissions with improved thermal efficiency. However, utilization of pine oil as a drop in fuel is challenging, due to its low cetane index. This leads to higher nitrogen oxide (NOx) emission due to prominent heat release rate. A novel fuel reforming system based on the principle of electrochemical liquid vortex ionization was used with permanent magnet/electromagnet to reduce NOx emission with pine oil as base fuel. Electrochemical liquid vortex ionization system converts the fuel molecules to ions; this leads to enhanced atomization and faster air–fuel mixing process leading to lower ignition delay. A two-cylinder commercial CI engine was used for this experimental study. Performance, emission and combustion characteristics were studied for pine oil with and without ionization system at 3, 6, 9 and 12 kW power output and compared with diesel. According to engine test results, compared to diesel, brake thermal efficiency for pine oil is higher and further improved with ionization system. Emissions like smoke, hydrocarbon, carbon monoxide and carbon dioxide are reduced for pine oil in comparison with diesel and further reduce with the ionization system. Longer ignition delay with pine oil operation leads to higher NOx emission compared to diesel. Nevertheless, the use of magnetic-based fuel reforming system reduces the ignition delay leading to lower NOx emission.

The current study compares the performance, emission and combustion characteristics of two different biofuel extracted from waste peels of lemon and orange fruit through steam distillation process in common rail direct injection engine. The study is further extended by variation of parameters such as injection pressures, split injection quantities and exhaust gas recirculation. The brake thermal efficiency for orange peel is higher than diesel and lemon peel oil at 600 bar with 10% of pilot fuel quantity. The similar cetane index of orange peel oil (OPO) means there is minimal performance drop for its blend and lemon peel oil (LPO) performs well as compared to diesel however this benefit is not greater than OPO. However, for 30% pilot fuel quantity the fuel efficiency is dropped by 10.74% and 4.72% for OPO and LPO respectively as compared to 10% pilot fuel quantity. Through the use of a greater quantity of pilot fuel injection, the low viscosity of LPO further increases its performance characteristics whereas OPO sees a decrement. The inherent oxygen content of both biofuel blends shows reduced emission of un-burnt hydrocarbon and carbon monoxide emissions under 600 bar and 10% pilot injection with the penalty of oxides of nitrogen emission.

This paper aims to evaluate the impact of cetane improvers on the combustion, performance and emission characteristics of a compression ignition engine fueled with a 20% peppermint bio-oil/diesel blend (P20). It is hypothesized that the low viscosity and boiling point of peppermint oil could improve the atomization characteristics of the fuel. However, the usage of peppermint oil is restricted due to its low cetane index. To improve this, Diethyl Ether (DEE) and Di- tertiary Butyl Peroxide (DTBP) are added to the P20 blend. The tests are performed in a single-cylinder naturally aspirated water-cooled diesel engine and results indicate that NOx emission for P20 + DEE and P20 + DTBP is decreased by 10.4% and 9.8%, respectively, when compared to P20 at full load condition. Among these two cetane improvers, DTBP is more effective in reducing the CO, HC and smoke emission and the performance of the engine was reported to be higher for P20 + DTBP blends.

Biodiesel and oxyhydrogen (HHO) gas have shown promising results in improving engine performance and emissions. In this work, the effects of HHO gas and 5% biodiesel blends (B5) and their combined use in a 315 cc diesel engine have been analyzed. Biodiesel is produced by base catalyzed transesterification and cleaned by emulsification. Its calculated cetane index (CCI) was 61.4. HHO gas is produced from electrolysis of concentrated potassium hydroxide solution. The use of 5% biodiesel blend resulted in a significant rise of 9.4% in the brake thermal efficiency (BTE) and a maximum reduction of 8.19% in the brake specific fuel consumption (BSFC). HHO enrichment of diesel and biodiesel at 2.81 L/min through the intake manifold improved the torque and power by an average of over 3%. HHO addition also improved the BTE of diesel by a maximum of 3.67%. The combination of high CCI biodiesel fuel and HHO creates a mixture that has shortened the ignition delay (ID) to the point that adverse effects were observed due to the premature combustion as shown by the average decrease in the BTE of 2.97% compared to B5. Thus, B5, on its own, is found to be the optimum fuel under these conditions. (c) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Diesel fuel mixtures with high concentrations of biodiesel have been investigated to analyze the technical feasibility of their use in diesel cycle engines regarding thermal and oxidative properties. The results of combined techniques of oxidative stability, high Pressurized Differential Scanning Calorimetry (P-DSC), Calculated Cetane Index (CCI), and calorific power were used to verify the effect of the thermal-oxidative stability as a function of the percentage of biodiesel in the mixtures. The obtained results evidenced that the thermal and oxidative stability decreased with the addition of biodiesel from 50 to 5% v/v. Low stability fuels require rapid use as the oxidation compounds degrade the product and impair vehicle performance, as well as lead to corrosion and clogging problems in various mechanical systems.

In the quest to find a potential alternative energy source for diesel engines, this paper proposes the use of a low viscous biofuel obtained from the waste lemon peels. The main advantage of this fuel is its lower viscosity; hence, no transesterification process is needed. A single cylinder CRDI water-cooled stationary test engine is used to test the fuel blends. All the measurements were carried out by keeping the engine speed as constant and varying its load values. The lemon peel oil was blended with diesel at 50% ratio. One major let-down using this oil is its lower cetane index value. To improve its cetane value, diethyl ether (DEE) is added with the blended fuel at three different proportions (5, 10 and 15% by vol.). The comparison of all the four blends with diesel fuel shows that the blend with 10% DEE produced much better results than others. When the test engine is operated at its maximum load condition, the exhaust pollutants like smoke, HC and CO were considerably reduced (27.05, 30.26 and 37.5%). It also managed to provide brake thermal efficiency much closer to diesel fuel, but 7.42% of NOx was increased along with 5.8% of fuel consumption. The 10% by vol. addition of diethyl ether provides the best outcomes.

An experimental investigation has been carried out to evaluate the performance, combustion, and emission characteristics of a twin-cylinder diesel engine fueled with mahua oil methyl ester (MOME)/diesel blends. The physicochemical properties of blended fuels were compared with baseline diesel as per the ASTM standard. Major challenges with mahua biodiesel are reduced thermal efficiency and a higher rate of oxides of Nitrogen (NOx) emissions hence to resolve this issue Di-ethyl ether (DEE) which has a higher cetane index, as well as lesser auto-ignition temperature, was mixed further with 20% mahua biodiesel/80% diesel blend(B-20) to improve the combustion characteristics of the blend. Initially, the engine was operated on the different blend proportion (5 to 20%) of mahua biodiesel mixed with neat diesel. The highest brake thermal efficiency was observed for AD-20(B-20+20%DEE) blend viz., around 30% at full load and 3% higher than neat diesel. Brake specific fuel consumption for the same blend was observed to be minimum viz., 12.16% reduction than neat diesel owing to improved ignition quality of the MOME blend causing complete combustion with the addition of DEE. Furthermore, the exhaust emissions such as smoke, NOx, unburnt hydrocarbon (UHC), and carbon monoxide (CO) were alleviated significantly by 55%, 7%, 35%, and 53%, respectively in comparison to normal diesel for AD-20 blend at maximum load. Hence, it can be concluded that MOME/diesel blend (B-20) mixed with 20% DEE gives the best result among all tested fuels.

This letter compares cetane index (CI) with biodiesel cetane index (BCI) of total fatty acid methyl esters (FAME) present in six seed oils. BCI of these FAME compositions estimated from its predicted and experimental densities is within the range of measured derived cetane numbers (DCN) in comparison to CI. Predicted and experimental densities of FAME compositions have a linear relationship with BCI compared to the reported plot of a single FAME density with cetane numbers. In conclusion, BCI estimated from FAME compositions of several lipid sources is a credible method to select fewer samples for measuring derived cetane numbers.

This study examined the use of waste plastic oil (WPO) combined with biodiesel as an alternative fuel for diesel engines, also commonly known as compression ignition engines, and focused on comparison of the basic physical and chemical properties of fuels, engine performance, combustion characteristics, and exhaust emissions. A preliminary study was conducted to determine the suitable ratio for the fuel blends in consideration of fuel lubricity and viscosity, and these results indicated that 10% biodiesel—derived from either palm oil or castor oil—in waste plastic oil was optimal. In addition, characterization of the basic properties of these fuel blends revealed that they had higher density and specific gravity and a lower flash point than diesel fuel, while the fuel heating value, viscosity, and cetane index were similar. The fuel blends, comprised of waste plastic oil with either 10% palm oil biodiesel (WPOP10) or 10% castor oil biodiesel (WPOC10), were selected for further investigation in engine tests in which diesel fuel and waste plastic oil were also included as baseline fuels. The experimental results of the performance of the engine showed that the combustion of WPO was similar to diesel fuel for all the tested engine loads and the addition of castor oil as compared to palm oil biodiesel caused a delay in the start of the combustion. Both biodiesel blends slightly improved brake thermal efficiency and smoke emissions with respect to diesel fuel. The addition of biodiesel to WPO tended to reduce the levels of hydrocarbon- and oxide-containing nitrogen emissions. One drawback of adding biodiesel to WPO was increased carbon monoxide and smoke. Comparing the two biodiesels used in the study, the presence of castor oil in waste plastic oil showed lower carbon monoxide and smoke emissions without penalty in terms of increased levels of hydrocarbon- and oxide-containing nitrogen emissions when the engine was operated at high load.

The present work aims to achieve simultaneous reduction of NO and smoke emission using waste tire pyrolysis oil (TPO) a third-generation fuel along with cetane improver namely diglyme (DGE) in a twin cylinder CI engine used in tractors. The solid waste tire disposal is getting much attention due to the environmental and health effects to humans. One of the methods to recycle used tire is to convert it to useful fuel to replace diesel in CI engine. Fuel derived from waste tire has comparable calorific value compared to diesel. TPO possess high viscosity and low cetane index causing improper atomization and increased ignition delay. This property of TPO reduces brake thermal efficiency (BTE) with higher NO and soot emissions. BTE for TPO is reduced by blending cetane improver, namely diglyme which subsequently improves the BTE along with reducing NO and smoke. The tests were conducted at constant speed of 1500 rpm with constant fuel injection pressure and timing. The tests were conducted at various load conditions corresponding to 25, 50, 75 and 100% of maximum brake power (BP). DGE was blended 10 and 20% with TPO on volume basis. NO emission increases from 1413 ppm for diesel to 1565 ppm for TPO and reduces to 1350 and 1235 ppm for TPO + DGE10 and TPO + DGE20 at 100% load. Smoke opacity increases from 62% for diesel to 70% for TPO and reduces to 67 and 63% for TPO + DGE10 and TPO + DGE20. TPO + DGE20 reduces maximum NO and smoke emission but brake thermal efficiency (BTE) is less due to high latent heat of vaporization. Hence, TPO + DGE10 is identified as optimum blend to simultaneously reduce NO and smoke emission with improved performance.

Biodiesel is a possible remedy to the present toxic, finite sources and ever-diminishing crude fuels. Nonedible and locally available (Azadirachta indica) neem seed oil (NSO) as a second-generation feedstock was transformed into biodiesel using calcined banana ash (CBA) derived from banana peels blended with lithium calcium oxide iron (III) sulphate Li-CaO/Fe2 (SO4)3 catalyzed transesterification. Transesterification process was employed to minimize the free fatty acid (FFA) content of NSO to afford 99.8% yield under the condition of the reaction oil/methanol ratio 8 : 1, followed by addition of 1.7%wt calcined banana peels ash and 1.3%wt Li-CaO/Fe2(SO4)3 catalysts in 53 min, a notable time. It is important to note that the physicochemical properties of biodiesel in this study such as initial boiling points, flash point, pour point, cloud point, density, kinematic viscosity, final boiling points, and cetane index met ASTM D-6751 and EN 14214 standards. Decomposition profile of CBA was displayed by thermal gravimetric analysis (TGA), whereas in-depth analysis by scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray fluorescence (X-RF), and Fourier-transform infrared spectroscopy (FT-IR) revealed that the high efficiency displayed by a catalyst from banana ash calcined at 650°C was due to the presence of potassium carbonate (K2CO3), a calcium magnesium silicate (CaMgSiO4), and potassium sodium sulphate (KNaSO4) contents that accounted for the high basicity of up to 11.09. Additionally, the nitrogen adsorption/desorption studies revealed that CBA interestingly exhibits a high BET surface area of 411.2 m2/g and promising mesopores (3.014 nm). The catalyst also displayed better recyclability evidenced by the fact that it was able to be reused after five successive runs with better recyclability of 75%. Based on the aforementioned properties, this work, therefore, opens an avenue for developing a supreme heterogeneous catalyst from available banana peels ash.