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Copyright of Journal of Engineering (17264073) is the property of Republic of Iraq Ministry of Higher Education & Scientific Research (MOHESR) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Threshold sooting index (TSI) is one of the critical properties related to the soot emission of diesel. Investigating the effects of TSI on the prediction of soot emission and the response of the soot model to TSI may improve our understanding of the soot formation process and model establishment during the combustion of diesel under engine-like conditions. To meet this need, two different d.iesel surrogates, named S1 and S2 were developed. S1 comprised n-dodecane, iso-octane, methylcyclohexane, and 1-methylnaphthalene, while S2 replaced 1-methylnaphthalene with toluene. Both were adjusted for similar cetane numbers, H/C ratios, and heating values, differing in TSI to analyze sooting tendencies to ensure the S1 and S2 had different soot tendencies but close ignition quality. Then, the skeletal mechanism containing the kinetics of the components in S1 and S2 was developed and validated against ignition delay times, speciation, laminar flame speeds and the 3-D spray combustion with results agreeing well with predictions. Finally, the soot performances of S1 and S2 in different soot models were compared in the constant volume combustion chamber (CVCC). The results showed that the comparison of S1 and S2 in different soot models could promote the understanding of soot models. [ABSTRACT FROM AUTHOR]

Methanol is a promising alternative fuel due to its wide availability of raw materials, mature production processes, and low production cost. However, because of the low cetane number, methanol must include a more reactive fuel to assist with combustion when used in compression ignition (CI) engines. In this study, based on the optical CI engine platform, methanol is injected into the intake port, and diesel is directly injected into the cylinder to achieve dual-fuel combustion. The effects of the methanol energy ratios and diesel split injection strategies on combustion are investigated. The results show that the premixed blue flame was mainly concentrated in the near wall region, whereas the yellow flame produced by diesel combustion tended to concentrate in the central region as the methanol energy ratio increased. When the methanol energy ratio exceeded 50%, the ignition delay was significantly prolonged, while the flame area was greatly reduced. Meanwhile, the peak values for the cylinder pressure and heat release rate decreased significantly, indicating a significant deterioration in combustion. At the earlier diesel pre-injection timing at −58°, the overall dual-fuel combustion at each main injection timing exhibited low-temperature premixed combustion characteristics, with a lower peak exothermic rate and flame brightness. At the later pre-injection timing at −33°, the spray flame at all main injection timings could be observed, with higher peak heat release rates and indications of thermal efficiency. Combustion at later main injection timings was characterized by diffusion combustion, and the main injection timing could effectively regulate the combustion process through phase adjustment. [ABSTRACT FROM AUTHOR]

The development of renewable sources for energy production has assumed a vital role in recent years, particularly with regard to the preservation of energy supplies and the environment. In this regard, municipal green waste (MGW) can be a potential renewable energy source if it is integrated with emerging technology, like pyrolysis. Therefore, this study aimed at investigating the effect of residence time and particle size on the yield and composition of oil derived from MGW using fast pyrolysis in an auger reactor. The residence time and particle size were varied from 1 min to 4 min and 1 mm to 10 mm, respectively, while keeping the temperature constant at 500 °C. At a residence time of 3 min, a 2 mm particle size provided the highest bio-oil yield (39.86%). At this experimental setting, biochar yield of 27.16% and syngas yield of 32.98% were obtained. The characterization of produced bio-oil revealed that a total of nine functional groups were present in the bio-oil. The phenols were highest in amount, followed by aromatics and ketones. The increase in residence time decreased the amount of acidic compounds present in the bio-oil. The water content was decreased by ~11% and the calorific value was increased by ~6% with the increase in particle size from 1 mm to 10 mm. Other properties, such as viscosity, density, cetane number, and flash point, did not change significantly with the change in experimental conditions. With a calorific value of 25+ MJ/kg, although the bio-oil produced from MGW can be used for heating (such as in boilers and furnaces), the use of MGW bio-oil in engines requires appropriate upgrading through procedures like hydrodeoxygenation, catalytic cracking, esterification, etc. [ABSTRACT FROM AUTHOR]

Diesel is one of the most common fuels which makes us think about how to save that type of fuel some theories are about losing Fossil diesel from the earth if we continue to use more and more. So biodiesel, one of the most prominent alternatives to diesel, is produced from waste cooking oil. It has a higher viscosity than diesel, despite its low cetane number. In the current study, an experimental work was carried out on a single cylinder of direct injection air-cooled diesel engine. A certain proportion of the test blended diesel was prepared of five blends, which are: (a) a mixture which consist of 80% diesel (D) and 20% biodiesel(B), (b) 80% diesel and 10% biodiesel was also dissolved with long-chain alcohol pentanol (P) at a rate of 10%, (c) the third is a mixture was prepared by adding 0.5gmAl2O3 to the second mixture of B10P10D80, (d) and 0.5gmFe2O3 particles added to B10P10D80, (e) the final blended fuel was compromised of 0.5gmAl2O3, 0.5gmFe2O3 particles added to B10P10D80. The engine performance and emissions were studied at variable engine loads which are ranged from 0.01 kW to 3.5 kW, and constant speed 3000rpm. The results showed that the brake-specific fuel consumption (BSFC) for the mixtures of B20D80, B10P10D80, B10P10D80+Fe2O3, and B10P10D80+Al2O3+Fe2O3 were increased by 26.08%, 30.4%, 1.3%, and 0.46%, respectively, due to oxygen availability in the composition. While it was found that B10P10D80+Al2O3 had a minimum BSFC of about 3.06%. These mixtures enhance the brake thermal efficiency (BTE), gradually. Concerning the emissions compared to diesel fuel (D100), the gases of (NOx), (CO), unburned hydrocarbons (HC), and smoke opacity were decreased. [ABSTRACT FROM AUTHOR]

The aim of this work was to measure the growth rate, biomass production, proximate composition, and fatty acid content of eleven microalgae strains to evaluate their potential for biofuel production. The growth rate (p < 0.05), total dry weight (p < 0.05), organic dry weight (p < 0.05), ash content (p < 0.05), and biomass productivity (p < 0.05) differed among eleven microalgae strains. The proximate composition differed (p < 0.05) among the eleven microalgae strains. The lipid contents were higher in Cymbella sp. (strain 2) (42.46 ± 1.06%) (p < 0.05). The carbohydrate content was higher (p < 0.05) in Aphanocapsa marina (42.40 ± 1.18 %). The protein content was significantly higher (p < 0.05) in Chlamydomonas mexicana (52.83 ± 0.60%). The contents of saturated (SFAs) (p < 0.05), monounsaturated (MUFAs), and polyunsaturated (PUFAs) (p < 0.05) fatty acids among the eleven microalgae strains were different. The most important indicators of biodiesel properties are the cetane number (CN), iodine value (IV), and saponification value (SV). It was concluded that Chlorella vulgaris was an adequate strain to be used in the production of biodiesel due to their high amount of palmitic acid, oleic acid, and alpha-linolenic acid, by high values of IV (147.27 g I2/100 g), SV (210.96 mg KOH/g), and CN (48.88). The diatom Cymbella sp. is a promising strain for biodiesel production due to its high values of lipid content (42.46%), lipid productivity (1.24 g/L/day), growth rate (0.67 divisions/day), and IV (197.93 g I2/100 g), and by the lowest values of generation time (35.60 h) and SV (208.85 mg KOH/g). Another promising strain for biodiesel production is Porphyridium cruentum due to its high values of biomass productivity (0.038 g/L/day), lipid productivity (0.80 g/L/day), CN (45.60), and IV (220.15 g I2/100 g), and by the low generation time and SV (199.25 mg KOH/g). [ABSTRACT FROM AUTHOR]

The lipid-producing gram-positive bacteria were isolated from soil and it was identified as Streptomyces fradiae JJ1 MK733985.1. Bacterial lipid synthesis was explored using rice washed water through the fermentation research. The exponential growth phase was reached on the fifth day of fermentation, according to the results. The ability of Streptomyces fradiae to produce microbial oil was compared to that of International Streptomyces Project-2 Medium (ISP2) medium. The results showed that RWW culture medium yielded 85.4% fatty acids and 60.3 g/L biomass, while ISP2 medium yielded 83.2% wt fatty acids and 59.5 g/L biomass. The microbial oil was transesterified into Fatty acid methyl esters (FAME), and its characteristics were studied using American Society for Testing Materials (ASTM) standards. The specific gravity was 0.864, the density was 0.863, the gross heating value was 42498 kj/kg, the cetane number was 37, and the acid value was 0.46. Streptomyces fradiae grew with an ISP2 density of 0.835, specific gravity of 0.845, gross heating value of 42326 kj/kg, and acid value of 0.43. According to the findings, Streptomyces fradiae isolated from soil can grow in RWW medium for the first time and provide the same yield as commercial media while being significantly less expensive. [ABSTRACT FROM AUTHOR]

This research work is focused on the production of liquid hydrocarbon fuel from plastic waste. To perform the experiments, polypropylene waste (PPW) and polyethylene terephthalate (PETW) were selected and pyrolyzed in a semi‐batch reactor at a temperature of 500°C. Nearly 72.28 wt.% of liquid fuel was recovered from 100 g of plastic waste feed through non‐catalytic pyrolysis process. The application of catalyst GO‐Szr to the pyrolysis process increased the oil yield to 92.76 wt.%. The oil properties were studied, to assess the characteristics and to compare with that of diesel fuel. The properties of oil were found to possess very good diesel properties such as kinematic viscosity of 2.18 mm2/s, density of 790 kg/m3, cloud and pour point less than −11°C, Sulphur content less than 3 ppm and cetane number was found to be as high as 72.44. From these studies, it is highlighted that waste plastics pyrolysis is a suitable option to produce diesel‐like fuel. [ABSTRACT FROM AUTHOR]

In this research, in addition to the quantitative and qualitative quantification of the biodiesel produced, the ability of the microalgae mix in the bioremediation of Cattle wastewater (CWW) was also evaluated. The biomass separation was conducted by a chemically assisted process with the addition of ferric chloride. The supernatant (treated ARB) showed high COD, TOC and NH + removal efficiency of 99.5, 99 and 98.6%. The dry biomass produced during the cultivation varied between 0.488 and 5.08 g L-1 and the lipid concentrations between 11 and 14%. The fatty acid in the highest concentration in the biomass was palmitic (C16:0, ranging from 75.7 to 81%. Linoleic acid (C18:3) ranged from 12.3 to 14.1%, indicating reasonable oxidative stability of biodiesel The calculations based on the fatty acids showed a cetane number of 58.8, an iodine number of 54.14 and an oxidation stability of 7.75 h. Although there are good conditions for using the produced biodiesel, it's recommended that it be mixed with other biofuels that have greater oxidative stability Overall this is a new sustainable route for biofuel production with the benefit of conducting wastewater bioremediation at the same time. [ABSTRACT FROM AUTHOR]

1,1‐Diethoxybutane is a high‐potential biofuel additive that enhances various fuel properties, which include cetane number, lubricity, biodegradability, and flash point. This work presents a kinetic and thermodynamic study on the acetalization reaction between butanal and ethanol in the presence of Amberlyst‐15 wet in a batch reactor. The experiments were conducted in the temperature range 313–333 K at atmospheric pressure with three different initial molar ratios of reactants and catalyst loadings. An optimal parameter setting to achieve maximum equilibrium conversion of butanal was derived from a parametric study with these three factors. The equilibrium constant for the reaction was determined. Standard thermodynamic properties of the reaction, such as enthalpy, entropy, and Gibbs free energy, were experimentally evaluated. The activity‐based two‐parameter Langmuir‐Hinshelwood‐Hougen‐Watson rate expression was used for reaction kinetics. The activity coefficients were calculated by the UNIFAC method. The kinetic parameters and the activation energy were evaluated from the experimental data. The experimental data and data predicted by the model were found to be in good agreement. [ABSTRACT FROM AUTHOR]

This study used a novel combination of cellulose nanocrystals (CNCs) and calcium oxide (CaO) nanocomposite (CaO/CNCs) for the production of biodiesel from waste cooking oil. The filter paper was used as a raw cellulose source to produce the CNCs from the acid hydrolysis of cellulose with sulfuric acid. The as-synthesized CaO/CNC nanocomposite is recyclable and environmentally friendly and was characterized using Fourier transform infrared spectroscopy, energy dispersive X-ray, scanning electron microscopy, and X-ray diffraction. The optimum process parameters investigated are a 20:1 methanol-to-oil molar ratio, 3-weight percent catalyst concentration, 60 °C temperature, and 90 min of reaction time. Under the optimum conditions, a biodiesel yield of 84% was obtained. The CaO/CNC nanocomposite achieved five times reusability, indicating its effectiveness and reusability in the transesterification reaction. The synthesized biodiesel chemical composition was examined using FTIR, GCMS, 1H-NMR, and 13C-NMR, and its properties, including specific gravity, color, flash point, cloud point, pour point, viscosity, sulfur content, sediments, water content, total acid number, cetane number, and corrosion test, were ascertained using ASTM standard practices. The outcomes were determined to fulfill global biodiesel standards (ASTM 951, 6751). Five successive transesterification processes were used to test the regeneration of the catalyst; the first three showed no distinct change, while the fifth cycle showed a reduction of up to 79%. The innovative composite CaO/CNC and used cooking oil are stable, affordable, and extremely successful for long-term biodiesel generation. [ABSTRACT FROM AUTHOR]

To meet climate targets, a global shift away from fossil fuels is essential. For sectors where electrification is impractical, it is crucial to find sustainable energy carriers. Renewable methanol is widely considered a promising fuel for powering heavy-duty applications like shipping, freight transport, agriculture, and industrial machines due to its various sustainable production methods. While current technological efforts focus mainly on dual-fuel engines in shipping, future progress hinges on single-fuel solutions using renewable methanol to achieve net-zero goals in the heavy-duty sector. This review examines the research status of technologies enabling methanol as the sole fuel for heavy-duty applications. Three main categories emerged from the literature: spark-ignition, compression-ignition, and pre-chamber systems. Each concept's operational principles and characteristics regarding efficiency, stability, and emissions were analyzed. Spark-ignition concepts are a proven and cost-effective solution with high maturity. However, they face limitations due to knock issues, restricting power output with larger bore sizes. Compression-ignition concepts inherently do not suffer from end-gas autoignition, but encounter challenges related to ignitability due to the low cetane number of methanol. Nonetheless, various methods for achieving autoignition of methanol exist. To obtain stable combustion at all load points, a combination of techniques will be required. Pre-chamber technology, despite its lower maturity, holds promise for extending the knock limit and enhancing efficiency by acting as a distributed ignition source. Furthermore, mixing-controlled pre-chamber concepts show potential for eliminating knock and the associated size and power limitations. The review concludes by comparing each technology and identifying research gaps for future work. [ABSTRACT FROM AUTHOR]

Biodiesel, an alternative to traditional diesel, is essential for the sustainability of long-term energy supplies and often synthesized through a non-alcoholic route called interesterification. The described synthesis method facilitates the modification of oil and fat by exchanging acyl radical groups between triglyceride and alcoholic acid (alcoholysis), fat (acidolysis), or ester (transesterification). Therefore, this research aimed to determine the effect of the reactant ratio between crude palm oil (CPO) and dimethyl carbonate (DMC), along with the use of an eco-enzyme catalyst, on biodiesel characteristics. The CPO:DMC ratio was 1:1.5, 1:2, 1:2.5, and 1:3, while the immobilized eco-enzyme catalyst was 2%, 3%, 4%, 5%, and 6% of CPO mass. The results showed that interesterification with a 1:3 reactant ratio using a 4%wt catalyst was the best procedure, producing biodiesel yield of 73.65%, density of 0.860 g/mL, viscosity of 4.63 mm2/s (cSt), flash point of 113 °C, calorific value of 34.454 MJ/kg, and cetane number of 70.6%. [ABSTRACT FROM AUTHOR]

Biodiesel is one of the alternative forms of diesel fuel and can be obtained using the transesterification process of waste cooking oil with a catalyst to accelerate the reaction. The heterogeneous catalyst from waste scallop shells is used due to its potential for being reused in the subsequent transesterification reactions. Heterogeneous catalysts can also be recycled, contributing to their environmentally friendly nature. This study aims to identify the performance of recycling a calcium oxide (CaO) catalyst from scallop shell waste on synthesis biodiesel. The method used is the transesterification method with the basic ingredients of waste cooking oil using a CaO catalyst. Then, after the transesterification process is complete, the catalyst is separated from the biodiesel and recycled to be reused in the transesterification process up to five times. The biodiesel samples obtained are identified for yield value, physico-chemical properties, thermal properties and performance. X-ray diffraction characterization results for the CaO catalyst show that it has a crystal size of 67.83 nm. Scanning electron microscope characterization shows that it has spherical particle shapes. Fourier transform infrared characterization shows the presence of Ca–O bonds. The highest biodiesel yield value of 74.23% is obtained in biodiesel Cycle 1. The flash point value of biodiesel samples ranges from 141.2°C to 149°C. Further, all of the biodiesel samples exhibit a cetane number of 75. The highest lower heating value of 38.22 MJ/kg is obtained in biodiesel Cycle 1 and the viscosity of the biodiesel samples ranges from 5.65 to 5.88 cSt. The density of the biodiesel samples ranges from 881.23 to 882.92 kg/m3. Besides, ester functional groups (C=O) and methyl functional groups have been successfully formed in all samples, with the methyl oleate compound observed as dominating the biodiesel samples. The cloud point value of the biodiesel samples ranges from 12°C to 13°C, and their pour point value ranges from 10°C to 12°C. The lead content in biodiesel is 0.8826 mg/kg. The lowest sulphur content is obtained from biodiesel Cycles 1 and 2 at 0.005%. Performance tests show that biodiesel has lower torque and brake power values than commercial diesel fuel and higher specific fuel consumption values than commercial diesel fuel. [ABSTRACT FROM AUTHOR]

Mahua oil is a remarkable fuel since it has a similar calorific value to diesel and has similar viscosity, flash point, and boiling points to diesel. However, since mahua oil has a lower cetane number than diesel when utilized as a blend, it displays a longer ignition delay and a greater peak heat release rate, resulting in higher NOx emission. To decrease the negative impact of mahua oil on NOx emission, an effort is made to introduce the ignition improver in different proportions (i.e., 5-20% by vol). Due to its higher latent heat, IAN shows some adverse effects on performance and emission outcomes. An investigation is conducted on a CRDI engine using mahua methyl ester blended with diesel by adding oxygenated additives to the engine characteristics. The emissions like HC, CO, and smoke were reduced by 16.32, 23.56, and 23.12%. The improved combustion process increases NOx and CO2 emissions by 13.62 and 19.89%. Also, an increase in HRR and CP values was noticed at full load operation. Additionally, it is observed that the engine's performance is enhanced using 15% Iso-amyl nitrate (IAN), indicating that the IAN blend is a useful ignition improver for mahua oil and diesel blends. [ABSTRACT FROM AUTHOR]

Copyright of DYNA - Ingeniería e Industria is the property of Publicaciones Dyna SL and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As a clean alternative fuel oil for marine engines, methanol has received increasing attention, but its low cetane number requires diesel ignition, which increases the difficulty of retrofitting existing engine fuel injection systems. Polymethoxy dimethyl ether (PODEn) is an ether fuel mixture whose chemical structural formula can be expressed as CH3O(CH2O)nCH3 ( n ≥ 2 ). PODE3 is the predominant component in the blend, and its properties are representative of the blend. PODE is a low-carbon fuel with a high cetane number and is easy to compression ignite, and, as such, can be used to ignite methanol in a marine diesel engine. This article explores the combustion mechanism of mixed methanol–PODE fuel using the characteristics of PODE that can be easily mixed with methanol for combustion. Taking methanol and PODE3 as representative fuels, the detailed combustion mechanism of PODE3 and the detailed combustion mechanism of methanol are simplified using a DRGEPSA (direct relationship graph with error propagation (DRGEP) and sensitivity analysis (SA)) method. Based on the target engine cylinder combustion environment, a simplified mechanism for mixed methanol–PODE fuel is obtained, and the new mechanism is validated in terms of the ignition delay period and laminar flame speed. The results indicate that the newly constructed simplified mechanism is basically consistent with the ignition delay data and flame propagation speed data measured by a rapid compression machine (RCM), laying the foundation for the application of alternative methanol fuels in marine engines. [ABSTRACT FROM AUTHOR]

A key characteristic of diesel engines is predicting the ignition delay period. This work predicts the ignition delay in diesel engines using combinations of ethanol/diesel fuel blend and pure diesel as fuel replacements. It provides an empirical formula for predicting delay periods. A growing interest in alternative fuel blends, representing a substantial shift from the use of traditional diesel fuel, is reported. Modern study is focused on examining these combinations and how they might affect the dynamics of combustion in diesel engines. Experiments were carried out utilizing five different ethanol/diesel fuel blends, including pure diesel, with ethanol percentages varying from 5% to 20% in 5% quantities. Tests were conducted at a constant engine speed of 1,500 rpm, with various compression ratios of 16, 17, and 18, with torque levels ranging from 0 to 21 N.m. In this study, general formulas for predicting ignition delay are constructed numerically. There was a greater consistency between the experimental outcomes and the expected ignition delay. The findings indicated that the E20 combined fuel continuously exhibited the least igniting delay period across all compression ratio variables. The findings demonstrated that the ignition delay period starts to shorten with increased cetane number, ignition pressure, temperature, and equivalency ratio. A shorter period of ignition delay is the outcome of higher compression ratios. The predictive model created here is a ground-breaking addition to the industry, offering a solid foundation for assessing the efficiency and emissions properties of different ethanol/diesel blends.

Global water scarcity increased the demand for clean water, leading to attention on microalgae-based biological treatment for wastewater due to economic feasibility and sustainable biomass applications. This study isolated indigenous microalga Coelastrella sp. KNUA068 from a wastewater treatment plant, observed its admissible growth rate in diluted cattle wastewater (DCW), and used it for wastewater treatment analysis. The microalga showed high growth rates in indoor and outdoor cultivation with 100% DCW. In addition, the ammonia nitrogen and nitrate nitrogen removal rates of the microalga were 69.97 and 60.35%, respectively, in indoor cultivation, and 50.63 and 67.20%, respectively, in outdoor cultivation. Carotenoid content analysis revealed lutein as the highest productivity carotenoid, and zeaxanthin production was higher in outdoor cultivation. The biomass exhibited suitable biodiesel quality with a cetane number of 50.8 for high-quality biodiesel production. Coelastrella sp. KNUA068 demonstrates potential for bioenergy feedstock, carotenoid production, and wastewater treatment. HIGHLIGHTS The valuable cetane number of microalgal biomass was suitable for high-quality biodiesel production.; The results of 20 L cultivation were similar to laboratory conditions.; Selection of strain that survives in livestock wastewater, and high growth rate of this microalgal strain.; Availability under the condition that microalgal biomass can be utilized as a byproduct.; High nutrient removal in a short period of time.;

The physicochemical properties of liquid alternative fuels are important but difficult to measure/predict, especially when complex surrogate fuels are concerned. In the present work, machine learning is used to develop quantitative structure–property relationship models. The fuel chemical structure is represented by molecular descriptors, allowing the linking of important features of the fuel composition and key properties of fuel utilization. Feature selection is employed to select the most relevant features that describe the chemical structure of the fuel and several machine learning algorithms are tested to construct interpretable models. The effectiveness of the methodology is demonstrated through the development of accurate and interpretable predictive models for cetane numbers, with a focus on understanding the link between molecular structure and fuel properties. In this context, matrix-based descriptors and descriptors related to the number of atoms in the molecule are directly linked with the cetane number of hydrocarbons. Furthermore, the results showed that molecular connectivity indices play a role in the cetane number for aromatic molecules. Also, the methodology is extended to predict the cetane number of ester and ether molecules, leveraging the design of alternative fuels towards fully sustainable fuel utilization.

Ammonia is a carbon-free, promising fuel for hydrogen carriers. It is a liquid fuel under low-pressure conditions (8.62 bars) and can be easily stored. Many researchers have tried to apply it in engines because there are no carbon dioxide emissions when combusting it. However, ammonia is a low cetane number fuel and is difficult to ignite. It can be used in a dual fuel mode in compression ignition (CI) engines, i.e., a fuel such as diesel, n-heptane, dimethyl ether, hydrogen etc., is used as a pilot fuel to ignite the ammonia. In this work, n-heptane was used as the pilot fuel and ammonia was used as the primary fuel in a light-duty CI engine. The engine's heat release rate (HRR), cylinder pressure, ignition delay and indicated efficiency were investigated experimentally at 80 %, 89 %, 95 % and 98 % ammonia fuel energy proportion. In order to investigate the ignition and combustion characteristics of the dual fuel engine, a multi-zone combustion model for n-heptane and a flame propagation model for the ammonia fuel were developed. In this work, it is found that the combustion process of n-heptane/ammonia can be simulated in most cases by a multi-zone evaporative combustion model combined with a flame propagation model. This work also found that the ignition performance of n-heptane is more affected by the long chemical ignition delay. Eventually, it was found that the more minor the discrepancy between the simulated and experimental ignition delays, the more insignificant the discrepancy between the simulated heat release rates and cylinder pressures and the experimental ones. The HRR, cylinder pressure, physical and chemical ignition delays and indicated efficiency of the engine were then simulated. The simulation showed good agreement with experimental results for the 89 %, 95 % and 98 % ammonia fuel energy proportion cases. The simulated physical ignition delay was 1.45–2.37 CA deg, the chemical ignition delay was 7.21–8.88 CA deg, and the indicated efficiency was 39.84%–42.80 % (for the three cases with 89 %, 95 % and 98 % ammonia fuel energy proportions). A detailed analysis of each parameter was conducted. • The n-heptane multi-zone model and flame propagation model for ammonia were jointly developed. • Combined theoretical and experimental analysis of combustion processes. • Analysis of the heat release rate and cylinder pressure of ammonia fuels with different energy proportions. • Prediction deviation in ignition delay largely determines prediction deviation in HHR and cylinder pressure. • Chemical ignition delay dominates the ignition performance. [ABSTRACT FROM AUTHOR]

Compressed Natural Gas (CNG) is recognized as an environmentally friendly alternative vehicle fuel, but it has a low flame speed. Combining hydrogen with CNG to create 'hydrogen compressed natural gas' (HCNG) allows for faster and leaner combustion. Additionally, OME 2 − 4 with varying cetane numbers, from 63 for OME 2 to 90 for OME 4 , serves as a highly reactive fuel suitable for use in a dual fuel strategy known as RCCI (reactivity-controlled compression ignition). This project investigates the impact of adding OME 2 − 4 to HCNG, focusing on pressure, temperature, and emissions. Results indicate that lengthening the OME chain advances the peak heat release rate but delays the second combustion phase. In diesel + HCNG , the first-phase combustion is 2 °CA shorter than OME 2 + HCNG , resulting in a 6.5% higher peak pressure than OME 2 + HCNG and a 20% increase over basic diesel. Lengthening the OME chain from OME 2 to OME 4 raises the peak pressure by about 6.2%. The addition of gaseous fuels, especially hydrogen, increases peak temperature by 16%. OME 4 + HCNG has a similar peak temperature to OME 3 + HCNG , while OME 2 + HCNG is about 1.5% lower than OME 4 + HCNG. [Display omitted] • The peak pressure for diesel + HCNG is approximately 20% higher than that of basic diesel (115.0 bar). • Lengthening the OME chain from OME 2 to OME 4 increases the peak pressure by 6.2% (from 134.9 bar to 143.3 bar). • The OME n + HCNG configurations decrease soot formation, reducing it from 1466 ppm in basic diesel to 6 ppm for OME 2 + HCNG. [ABSTRACT FROM AUTHOR]

This article investigates the volatilization characteristics of binary and ternary fuel blends of cottonseed partially hydrogenated biodiesel, ethanol, and conventional diesel. The vapor pressure, enthalpy of evaporation, and activation energy of the fuel blends were obtained by thermogravimetric analysis and kinetic calculation. The physicochemical properties of the fuel blends showed that the ternary fuel blend of suitable mixing ratio had satisfactory cetane number, improved oxidation stability, and oxygen content with a significant decrease in the kinematic viscosity. In addition, the vapor pressure of the PHCME ternary fuel blends was increased by 18.4%, 17.2%, and 20.4% compared with PHCME binary fuel blends, and the enthalpies of evaporation of the ternary fuel blends increased slightly with different mixing ratios. The activation energy of PHCME ternary fuel blends was decreased by 3.5%, 6.8%, and 16.3% respectively, compared to the PHCME binary fuel blends. In conclusion, ethanol addition in the PHCME fuel blend improved the volatilization characteristics and the kinematic viscosity of the fuel blend without a significant adverse effect on the fuel properties of hydrogenated biodiesel. [ABSTRACT FROM AUTHOR]

This research article examines engine performance characteristics using three different volumetric blending ratios of high-viscosity Simarouba glauca seed oil and low-viscosity camphor oil: 30% Simarouba glauca oil with 70% camphor oil (S30C70), 50% Simarouba glauca oil with 50% camphor oil (S50C50), and 70% Simarouba glauca oil with 30% camphor oil (S70C30). At full load, the thermal efficiency of S30C70 was found to be 8.18, 5.64, and 4.09% higher than that of S70C30, S50C50, and diesel fuel. In comparison to S70C30, S50C50, and diesel, the energy usage for brakes was determined to be 7.54, 5.34, and 3.64% lower. At high loading circumstances, S30C70 emits 57% less CO than the basic fuel value. Similar to the basic fuel, smoke and hydrocarbon emissions are trending downward. In comparison to base diesel, NO emission for the S30C70 fuel mix was about 20.33% higher under heavier loading situations. The maximum in-cylinder peak pressure and rate of pressure increase are exhibited in S30C70, which has a lower cetane number. The S30C70 fuel blend offers higher fuel exergy, relative efficiency, sustainability index, and exergy efficiency due to its low viscosity. The S30C70 fuel blend was found to have lower entropy than all other combinations tested. When a higher volume of camphor oil is added to the blended fuel, the performance characteristics of the diesel engine increase significantly. [ABSTRACT FROM AUTHOR]

In recent years, researchers have turned their attention to the co-cultivation of microalgae and plants as a means to enhance the growth of hydroponically cultivated plants while concurrently producing microalgal biomass. However, the techniques used require precise calibration based on plant growth responses and their interactions with the environment and cultivation conditions. This study initially focused on examining the impact of hydroponic nutrient concentrations on the growth of the microalga Chlorella sp. AARL G049. The findings revealed that hydroponic nutrient solutions with electrical conductivities (EC) of 450 µS/cm and 900 µS/cm elicited a positive response in microalgae growth, resulting in high-quality biomass characterized by an elevated lipid content and favorable properties for renewable biodiesel. The biomass also exhibited high levels of polyunsaturated fatty acids (PUFAs), indicating excellent nutritional indices. The microalgae culture and microalgae-free culture, along with inoculation-free lettuce (Lactuca sativa L. var. longifolia) and lettuce that was inoculated with plant growth actinobacteria, specifically the actinomycete Streptomyces thermocarboxydus S3, were subsequently integrated into a hydroponic deep-water culture system. The results indicated that several growth parameters of lettuce cultivated in treatments incorporating microalgae experienced a reduction of approximately 50% compared to treatments without microalgae, and lowering EC levels in the nutrient solution from 900 µS/cm to 450 µS/cm resulted in a similar approximately 50% reduction in lettuce growth. Nevertheless, the adverse impacts of microalgae and nutrient stress were alleviated through the inoculation with actinomycetes. Even though the co-cultivation system leads to reduced lettuce growth, the system enables the production of high-value microalgal biomass with exceptional biodiesel fuel properties, including superior oxidative stability (>13 h), a commendable cetane number (>62), and a high heating value (>40 MJ/kg). This biomass, with its potential as a renewable biodiesel feedstock, has the capacity to augment the overall profitability of the process. Hence, the co-cultivation of microalgae and actinomycete-inoculated lettuce appears to be a viable approach not only for hydroponic lettuce cultivation but also for the generation of microalgal biomass with potential applications in renewable energy. [ABSTRACT FROM AUTHOR]

This research work focuses on the stability and physicochemical characteristics of chromium oxide (Cr2O3) nanoparticles in Mesua ferrea biodiesel (BD20). The Cr2O3 nanoparticles were combined at 60, 80, and 100 mg/L. The dispersant (QPAN80) and surfactant (CTAB) were introduced (at 1:1 ratio) for the Cr2O3 nanoparticles. A mechanical agitator and probe sonicator were used to introduce Cr2O3 nanoparticles into BD20. The stability and physicochemical properties of various nanofuel samples were tested. A spectrophotometer was used to measure stability (absorbance and transmittance) on two separate days, Day 1 and Day 20. Compared to CTAB mixed and base nano fuels, dispersant-based nano fuels were shown to be more stable. Furthermore, the inclusion of Cr2O3 nanoparticles together with dispersion and surfactants improved important fuel properties. In terms of stability and physicochemical properties, BD20 + Cr2O3 80 mg/L + DSP 80 mg/L has shown better outcomes than remaining fuels. The heating value and cetane number were improved for surfactant and dispersant added Cr2O3 nano fuel while the viscosity, relative density, and flashpoint were shown slightly opposed results. The higher absorbance and lower transmittance were perceived as 4.58 and 87.7% while the heating value and cetane number were 41.33 MJ/kg and 60, respectively, for BD20 + Cr2O3 80 mg/L + DSP 80 mg/L. [ABSTRACT FROM AUTHOR]

In this study, the Palm and Juliflora biodiesel (PJ100) mixture is prepared in the proportion of (50% palm biodiesel by volume and 50% juliflora biodiesel by volume). The different fuel samples were prepared with PJ100 and diesel. 20% of PJ100 + 80% of diesel (B20), Partial hydrogenation of PJ100 was carried out and prepared 20% of hydrogenated PJ100+80% of diesel (HB20) and 2000 ppm of DTBP (Di-tert-butyl peroxide) additive was added with B20 (B20 + DTBP). The above fuel samples examined a single-cylinder diesel engine's combustion and emission characteristics. An autoclave reactor was used for the hydrogenation of PJ biodiesel, and gas chromatography was used to evaluate the fatty acid composition of biodiesel. Tamson FBT equipment was used to verify the filterability characteristics of all the biodiesel blends and diesel. The FBT results show that B20 and HB20 are 1.36 and 1.4, respectively, which aligns with the ASTM standard (D2068-14). Ignition delay and combustion duration of HB20 and B20+DTBP are significantly improved than the B20 blend. The Brake thermal efficiency of HB20 is 7.7% higher than B20. Similarly, NOx emission was reduced in HB20, and B20+DTBP fuels were 8.66% and 9.74%, respectively, compared to the B20 blend. Based on the above findings, a partial hydrogenation (HB20) blend has been a better way to improve the trade-off qualities than adding DTBP with B20. [ABSTRACT FROM AUTHOR]

In the field of biodiesel, the oxygenised alternatives, dimethyl ether (DME) and diethyl ether (DEE), are the promising alternative due to high Cetane number and oxygen content. In this research, experimental analysis is done for different fuel blends of Jatropha oil and DEE as additives. Biodiesel of 10, 15, and 20% with 10% DEE is used by mixing with diesel named as A1, A2 and A3. For 20% of DEE with same % of biodiesel, second batch of blends is prepared as B1, B2 and B3. These blends are prepared, and their physicochemical properties are tested. The compression ratio (CR) at 16, 17 and 18 is used as input for engine performance and emission analysis. Load on the engine is increased from 3 kg to 12 kg as full load for all blends and diesel. Results shows that engine gives better performance at higher load and higher CR. A3 blend shows the highest value of BTE than other fuel blends and diesel at all CR and loads. A3 blend shows the lowest value of BSFC compared to other fuel blends at CR 16 and CR 18. Performance of A3 and B2 fuel blends is better than all other fuel blends. [ABSTRACT FROM AUTHOR]

This investigation evaluates the impact of four distinct diesel fuel types, produced in Kurdistan, on a single-cylinder, direct-injection diesel engine's performance and emission characteristics at a compression ratio of 17. An experimental approach was adopted to examine the influence of fuel type on brake thermal efficiency (BTE), brake specific fuel consumption (BSFC), exhaust gas temperature (EGT), and emissions including carbon monoxide (CO), unburned hydrocarbons (UHC), nitrogen oxides (NOx), and smoke opacity. Additionally, the study scrutinized the effects of a constant cetane number (CN) across different fuel types in relation to engine output and pollutant generation. It was found that, in comparison to diesel type 1, type 3 fuel reduced smoke opacity by up to 35% while increasing BSFC by 18.18%. CO emissions associated with types 3 and 4 were 53.84% and 34.6% lower, respectively, than those measured for type 1. Except for type 1, all tested diesel variants emitted significantly lower UHC concentrations across the full load range. Conversely, diesel type 1 was linked to higher NOx emissions. The findings suggest that types 4 and 3 diesel fuels enhance combustion and emission profiles in diesel engines, presenting a potential avenue for optimization in engine performance and environmental compliance. [ABSTRACT FROM AUTHOR]

Present dependence on fossil sources for meeting energy demand globally is unsustainable as a result of non‐renewable and depleting supplies. Therefore, this study focuses on production and characterization of biodiesel by Chlorococcum littorale (Chlorococcum sp.) isolated from fish pond in Owode fish farm, Nigeria. Biomass concentration, lipid extraction and quantification were determined by filtration, solvent extraction and gravimetric methods. Extracted lipid was transesterified to diesel through process catalyzed by concentrated tetraoxosulphate (VI) acid. The constituents of fats in biodiesel produced were examined through chromatography of gas and spectroscopy of mass. Model prediction was used to assess physical and chemical parameters of biodiesel. The data gathered was subjected to statistical analysis. Chlorococcum sp. had biomass concentration (4.42 ± 0.02 g/L), Lipid content (67.75% and biodiesel yield (96.33%). Biodiesel had 48.3%, 29.20%, and 22.50% fatty acids that are saturated, monounsaturated and polyunsaturated, respectively. The biodiesel produced has the kinematic viscosity (2.74 mm2/s at 40°C); point of flash (245°C); point of cloud (7°C); point of pour (−2°C) and density (0.8760 g/cm3). Furthermore, the acidity level (0.44 mgKOH/g), value of saponification (186.49 mgKOH/g), value of peroxide (3.25 meq/kg), iodine content (38.27 mgI2/g) as well as the free fatty acid (1.34%), number of cetane (65.78), oxidative resistance (7.33 h), saturated factor of long chain (28.16°C), plugging point of cold filter (35.62°C) and high heating value (43.24°C) fell within required standard by international body. Thus, Chlorococcum sp. is ideal microalgae isolate for the biodiesel production. The biodiesel produced conform satisfactorily with the acceptable global standard. HIGHLIGHTS: Biodiesel exhibited good stability of oxidation and a high number of cetane.Presence of C16 and C18 fatty acids as well as saturated fat.Physicochemical characterization tests for biodiesel produced show that the quality of biodiesel produced was of high standard.Biodiesel produced has properties that met standard by international bodies. [ABSTRACT FROM AUTHOR]

Fast depletion and higher emissions of fossil fuels are posing problems to scientists across the globe. To overcome this, thorough research is needed to find out alternate renewable sources. Biodiesel is such a renewable, biodegradable, and innocuous fuel to meet this global need. Oil extracted from vegetable oil seeds is processed into biodiesel by the transesterification process. The experimental work is carried out to study the performance and emission characteristics of a single‐cylinder, air‐cooled diesel engine by using a mixture of two diverse biodiesels namely Pongamia and Mahua. The results indicate that at higher loads there is a reduction of smoke emission for the 100PM blend (50% Pongamia biodiesel and 50% Mahua biodiesel) along with a 4.4% reduction in brake thermal efficiency when compared to diesel. The smoke is reduced for 100PM by 78.4% and 70.8% and for 50D50PM (50% diesel and 25% each biodiesel) by 71% and 61% at higher loads. From the combustion analysis, it is found that peak cylinder pressure for 100PM and 50D50PM blends are higher when compared with diesel which may be due to the advanced start of injection and ignition of blends. Injection and ignition advance of the blends may be attributed to higher bulk modulus and higher cetane number of biodiesels. [ABSTRACT FROM AUTHOR]

As energy needs continue to rise in line with the use of fossil energy, which is difficult to renew, other alternative energy is needed to continue to meet current and future energy needs. One alternative energy that is easy to produce is biodiesel. One of the raw materials that is quite widely used and developed in making biodiesel is waste cooking oil. According to statistical data, Indonesia can produce waste cooking oil of 5.06 tons per year. Waste cooking oil contains free fatty acids that can be processed into biodiesel using the help of heterogeneous catalysts. One source of heterogeneous catalysts that can be used is CaO, which can be found in green shells, where the CaO contained can be taken through the calcination process of green shells. To maximize the waste cooking oil processing process, an adsorption pretreatment process can be carried out. The adsorption process is carried out to reduce the FFA levels and acid numbers contained in waste cooking oil so that the transesterification reaction process can run optimally. Natural zeolite can be used as a good adsorbent to purify and lower the acid number of waste cooking oil. This study aims to find the best operating conditions in producing biodiesel made from waste cooking oil with a pretreatment adsorption process using natural zeolite and green shell catalyst through the factorial design method, where from the results of the research carried out, it was found that the density and viscosity met the SNI, the biodiesel yield produced was 45-65% and the cetane number test on samples 3 and 7 was 34,7 and 34,2 which did not meet the SNI. The operating temperature and amount of catalyst used in the biodiesel manufacturing process produce biodiesel with good density, viscosity, and yield, namely at a temperature of 60°C and a catalyst content of 6 grams. The operating temperature of 65°C produces a smaller density because the boiling point of alcohol is 64.7°C, so the reaction process is not perfect. [ABSTRACT FROM AUTHOR]

The objective of current investigation is to assess the diesel engine performance, combustion, and emissions fuelled with bismuth ferrite codoped with zinc and manganese (BZnFMO) nanoparticles dispersed Terminalia bellirica biodiesel. BZnFMO nanoparticles were uniformly dispersed in B20 together with the surfactant and the dispersant at a concentration of 50 ppm and 75 ppm, respectively, and the stability of the nanoparticles in B20 was evaluated by UV photo spectroscopy. In addition, the experimental analysis of all nano-fuel samples was tested on diesel engines with different injection timing (i.e. 21°bTDC, 23°bTDC and 25°bTDC). The addition of nanoparticles in B20 led to an improvement in performance and combustion properties while simultaneously reducing emissions. The dispersion of BZnFMO nanoparticles in B20 led to a significant improvement in cylinder pressure (CP), cumulative heat release rate (CHRR), rate of pressure rise (RoPR) and brake thermal efficiency (BTE), while reducing brake specific fuel consumption (BSFC), carbon monoxide (CO), unburnt hydrocarbons (UHC), nitrogen oxides (NOx) and diesel engine smoke opacity. The increase in injection timing also led to an improvement in performance and combustion characteristics, as well as a reduction in emissions, with the exception of NOx. At 25°bTDC, a CP of 71.14 bar, a CHRR of 3.27 J/°CA and a RoPR of 5.3 bar/°CA were found, while BTE and BSFC were 35.03 % and 0.391 kg/kWh, respectively for B20 + 75 ppm BZnFMO + 75 ppm TWEEN 80. The values for CO, UHC, NOx, smoke opacity and nitrogen oxides were 0.01 %, 22 ppm, 826 ppm and 35.85 % respectively.

This study aims to ascertain the operating parameters of a Copper oxide nanoparticle and Azadirachta indica biodiesel-powered diesel engine. Copper oxide nanoparticles were considered at 75 ppm, and three dispersants were added at the same ratio as nanoparticles. An ultrasonic bath sonicator was used to sonicate the nanoparticles, and later, the ultrasonicator was used to prepare the nanofuel. The experiment was conducted on a diesel engine with different injection timings, such as 21 °bTDC, 23 °bTDC, and 25 °bTDC at full load. The performance was slightly improved by mixing nanoparticles with B20, and it got even better by adding dispersants. The combustion parameters were also changed compared to diesel. Finally, the emissions of carbon monoxide, unburnt hydrocarbons, nitrogen oxides and smoke opacity were significantly reduced by the dispersion of nanoparticles. Increasing the injection timing also led to better results, and 25 °bTDC showed better results. The B20+CuO75+QPAN 75 has shown the most remarkable effects among other samples. At 25°bTDC, the brake thermal efficiency, brake specific fuel consumption, cylinder pressure, net heat release rate, were 35.03 %, 0.391 kg/kWh, 66.23 bar, and 89.39 J/°CA, respectively, while carbon monoxide, unburnt hydro carbons, smoke, and oxides of nitrogen were 0.089 %, 32 ppm, 19.351 %, and 1238 ppm.

Fossil fuel is a non-renewable fuel, and with the development of modern industry and agriculture, the storage capacity of fossil fuels is constantly decreasing. In this study, a systematic study and analysis were conducted on the combustion characteristics, engine performance, and exhaust emission characteristics of castor biodiesel–diesel blends and pure diesel fuel in different proportions at different speeds of a single-cylinder four-stroke diesel engine under constant load. The castor biodiesel required for the experiment is generated through an ester exchange reaction and mixed with diesel in proportion to produce biodiesel–diesel blends. The experimental results show that as an oxygenated fuel with a higher cetane number, the CO, HC, and smoke emissions of diesel and B80 blend fuel at 1800 rpm were reduced by 16.9%, 31.6%, and 68%, respectively. On the contrary, the NOx and CO2 emissions increased by 17.3% and 34.6% compared to diesel at 1800 rpm. In addition, due to its high viscosity and low calorific value, the brake thermal efficiency and brake-specific fuel consumption of the biodiesel–diesel blends are slightly lower than those of diesel, but the biodiesel–diesel blends exhibit lower exhaust gas temperatures. Comparing B80 and diesel fuel at 1800 rpm, the BSFC of diesel at 1800 rpm is 3.12 kg/W·h, whereas for B80 blended fuel, it increases to 4.2 kg/W·h, and BTE decreases from 25.39% to 21.33%. On the contrary, B60 blended fuel exhibits a lower exhaust emission temperature, displaying 452 °C at 1800 rpm. Based on the experimental results, it can be concluded that castor biodiesel is a very promising clean alternative fuel with low waste emissions and good engine performance. [ABSTRACT FROM AUTHOR]

The aim of this research was to investigate experimentally the performance and combustion characteristics of a four‐stroke, single‐cylinder, water‐cooled variable compression ratio diesel engine using rice bran oil biodiesel blends with zinc oxide nanoparticles. Rice bran oil biodiesel was prepared using a transesterification reaction with a 6:1 methanol‐oil molar ratio and 1% w/w potassium hydroxide as catalyst. Zinc oxide nanoparticles were synthesized using a green method incorporating Psidium guajava leaf extract as a capping agent to reduce precursor use and to reduce the toxicity of the nanomaterial. The synthesized zinc oxide nanoparticles were characterized by using X‐ray diffraction and Fourier‐transform infrared spectroscopy to confirm the formation of highly crystalline pure zinc oxide nanoparticles with a hexagonal wurtzite crystal structure with an average diameter of 20.963 nm. Rice bran‐oil biodiesel‐diesel blend was prepared by volumetrically mixing 20% biodiesel and 80% mineral diesel and was considered as a base fuel for comparison. Zinc oxide nanoparticles were diffused in the base fuel at dosage levels of 25, 50, and 75 ppm, with the aid of ultrasonication. Measurement of the major physicochemical properties of test fuels showed an increase in the cetane number and calorific value and a reduction in viscosity with an increase in the zinc oxide concentration. The overall properties of all the test fuels were found to be similar in comparison with commercial diesel. An experimental engine test was carried out under different loading conditions with a constant speed of 1500 RPM and two different compression ratios – that is, 17.5:1 and 15:1. Among all the test fuels at both compression ratios, engine performance and combustion properties improved with an increase in the zinc oxide concentration. Test fuel with 75 ppm of zinc oxide additive at 17.5 compression ratio resulted in an overall improvement at full load: brake thermal efficiency increased by 2.45%, brake specific fuel consumption reduced by 5.45%, cylinder peak pressure increased by 3.27% and net heat release increased by 10.32% in comparison with base fuel. [ABSTRACT FROM AUTHOR]

Utilization of fossil fuels results to toxic emissions that adversely affect the environment. In order to arrest this challenge it is pertinent to rely more on cleaner fuels. This study evaluates the potential of producing clean and affordable fuel, biodiesel, in line with United Nations Seventh Sustainable Development Goal. Cotton and calabash seeds were used to produce biodiesel in this study. The seeds were mixed at different ratios and the catalyst concentration was controlled at 1% for two hours under a temperature of 60°C. About 70% of the cost of producing biodiesel rests on feedstock alone. To reduce cost, cheap and underutilized seeds were chosen for this study. In addition, the biodiesel was produced via a technique, in situ transesterification, which lowers production cost. In this process the oil from the seeds were extracted and converted to biodiesel in a single step. The highest yield of 61.33% was obtained at a ratio 1:5 of the cotton to calabash seeds respectively. The physicochemical parameters analysed for are: saponification value (210.38 mg KOH/g); iodine value (59.14 mgI2/100g); acid value (1.68 mg/g); free fatty acid (0.84); cetane number (58.93); ester value (208.7); high heating value (39.91 MJ/kJ) and specific gravity (0.87). The results of the properties were compared with standards and this shows that the biodiesel produced has very good properties. [ABSTRACT FROM AUTHOR]

In this work, in addition to the quantitative and qualitative quantification of the biodiesel produced, the ability of the microalgae mix in the bioremediation of cattle wastewater (CWW) was also evaluated. The biomass separation was carried out by a chemically assisted ferric chloride. The supernatant (treated CWW) showed high COD, TOC, and NH4+ removal efficiency of 99.5, 99, and 98.6%, respectively. The dry biomass produced during the cultivation varied between 0.5 and 5.1 g L−1 and the lipid concentrations between 11 and 14%. The fatty acid in the highest concentration in the biomass was palmitic (C16:0), ranging from 75.7 to 81%. Linoleic acid (C18:3) ranged from 12.3 to 14.1%, indicating reasonable oxidative stability of biodiesel. The calculations based on the fatty acids showed a cetane number of 58.8, an iodine number of 54.14, and an oxidation stability of 7.75 h. Although there are good conditions for using the produced biodiesel, it is recommended that it be mixed with other biofuels that have greater oxidative stability. Overall, this is a new sustainable route for biofuel production with the benefit of carrying out wastewater bioremediation at the same time. [ABSTRACT FROM AUTHOR]

This paper explores pathways to achieve marine diesel-like, high-efficiency combustion fueled with propane in a RCEM research engine. Analyzing the novel technique of liquid propane injection is worthwhile given the potential for using propane in high-efficiency compression ignition engines. Since propane has a low cetane number, spark plug operating is provided to achieve reliable ignition. Investigations into combustion and the effect of spark discharge energy on propane direct injection were done through experiments on a modified head large bore RCEM with three spark ignition strategies and simulations. The findings demonstrate that the simultaneous ignition strategy had the greatest total released energy (roughly 190 mJ/s). When the SOI of the direct injection propane was set at 20oCA BTDC, diesel more efficiently than propane (on average, 3.46%). The benefits of the chosen strategy for achieving diesel efficiency parity were shown by the increasing of combustion efficiency when the spark period was lengthened. • In-cylinder combustion, performance characteristics and spark discharge energy were investigated. • Spark ignition was applied on RCEM research engine fueled with liquid propane direct injection. • Investigating the in-cylinder flow and velocity distribution around spark plug. • Spark plug ignition duration was investigated to achieve reliable ignition and reasonable ignition delays. • RCEM with spark produces high in-cylinder pressure when the SOI of liquid propane direct injection was set at 20 oCA BTDC. [ABSTRACT FROM AUTHOR]

This study investigates the co‐hydroprocessing of light cycle oil (LCO) with waste cooking oil (WCO) as a potential strategy to enhance LCO′s qualities and overall performance. The study involves the integration of LCO with WCO in three different ratios, facilitating a combined hydrotreatment process within a fixed bed continuous down‐flow reactor. The findings reveal that incorporating WCO into LCO hydrotreatment enhances LCO′s properties, albeit with a minor reduction in hydrodesulfurization efficacy. WCO demonstrates approximately 10.7 % density and 26 % cetane number improvements compared to the LCO/WCO (70/30) blend at 380 °C. The most significant reduction in di and poly‐aromatic compounds is observed at 340 °C for pure LCO, while WCO inclusion has minimal impact on poly‐aromatic saturation. The yield range for medium distillates across all products is between 87 % and 93 %. The time‐on‐stream study suggests excellent catalyst stability and activity up to 456 h, which is one of the highest lifetimes reported so far. TGA study of the spent catalyst indicates 22 wt % coke deposition complemented by TEM results. FTIR analysis revealed absorptions of alicyclic hydrocarbons‐type compounds deposited over the catalyst surface. This research contributes to the development of innovative catalysts for selectively converting LCO and WCO into diesel‐range hydrocarbons through single‐step process. [ABSTRACT FROM AUTHOR]

In the literature, multiple linear regression, machine learning methods, and group contribution methods have been employed to estimate the cetane numbers of pure biodiesels based on their properties (composition of fatty acid esters, number of carbon atoms, number of double bonds, chain length, saponification number, iodine value, etc.). However, there has been relatively limited research on the relationship between cetane number and other fuel properties. Therefore, this study purposes to utilize the multiple non-linear regression method to estimate the cetane numbers of pure biodiesels as functions of the density, kinematic viscosity, flash point, and heating value. To establish correlations, experimental data on the fuel properties of 100 different biodiesels (methyl and ethyl esters) were gathered from the literature. The predictive performances of the proposed multiple non-linear correlations were compared with the commonly recommended multiple linear correlation found in the literature. According to the results, reliable non-linear correlations, having relative errors of less than 5% and high coefficient of determination values (r²) were obtained. [ABSTRACT FROM AUTHOR]

The objective of this study is to examine the impact of multifuel blends on combustion parameters of single-cylinder four-stroke direct injection diesel engines. Engine characteristics (performance, combustion, and emissions) are scanned under the following scenario: initially powered by regular diesel (DF), then 20% biodiesel derived from spirulina green algae. Afterward, 40% water ammonia solution (25% NH3) is used, followed by a hybrid blend (40% DF + 20% biodiesel + 40% NH4OH). Simulations are performed using Diesel-RK software. In contrast to diesel and biodiesel, aqueous ammonia solution has a longer delay period due to lower cetane number. In comparison with diesel, the Sauter mean diameter (SMD) is increased by 1.6%, 3.8% for biodiesel and NH4OH, while it is decreased by 13% for hybrid fuel. Peak values of pressure and temperature are reduced. All fuel blends under consideration had significant reductions in nitrogen oxides (NOx) and Bosch smoke number (BSN). Hybrid fuel reduced NOx emissions by 37% and BSN by 53.5% compared to DF. Compared to DF, there was a slight increase in brake-specific fuel consumption (BSFC) coupled with a decrease in thermal brake efficiency (BTE). The optimal fuel compromise for dual-fuel diesel engines is the usage of biodiesel and aqueous ammonia together (hybrid mode). There is an excellent convergence between these outcomes and those of other scientists. [ABSTRACT FROM AUTHOR]

Pongamia (Pongamia pinnata) is a prospective biofuel plant with 35 to 45% seed oil. The physical and chemical characteristics of pongamia oil are quite comparable to those of diesel. Pongamia seed oil has been considered as a possible biodiesel source for the past 10 years. The high viscosity and conradson carbon residue of pongamia oil, however, preclude its usage in this capacity. Thus, methyl ester was produced from pongamia oil by optimising the different parameters of transesterification reaction viz., reaction time (90 minutes), amount of catalysist (1.5 wt.%), amount of methanol (210 ml per liter of oil) and optimum temperature (50 °C) needed to complete the conversion of oil into methyl ester. The produced methyl ester was employed as fuel instead of diesel in the engine test using a single-cylinder, naturally aspirated, direct injection diesel engine. Parameters such engine speed, electrical efficiency, lower and higher heating values, and fuel consumption were investigated. Speed regulation and voltage regulation in the engine experiment provided clear evident that the biodiesel from pongamia oil could be used in an existing diesel engine without any engine modifications. The physical and chemical properties of the methyl ester were also estimated. The biodiesel produced from quality pongamia seed meets the cetane number (52.90) and iodine value (99) as per the biodiesel quality specifications and can be used in varied climatic conditions. [ABSTRACT FROM AUTHOR]

Progressive and increasingly noticeable climate change is forcing the search for new energy sources to reduce greenhouse gas emissions, especially carbon dioxide. One way to reduce greenhouse gas emissions is by gradually replacing fossil fuels with biofuels. The authors of this work addressed the production of second-generation biofuel. The purpose of this study was to produce second-generation biodiesel from babassu palm oil (BBuE) and first-generation biodiesel from rapeseed oil (RME), to study their properties, and to determine the effect of the addition of these biodiesels to diesel fuel on selected properties of "B" fuels that affect the fuel–air mixture formation process and the combustion process. Biodiesel from babassu oil was produced because it is non-edible and has a different composition than canola oil. Then, fuels were prepared that were mixtures of diesel oil and biodiesel containing from 10 to 40% (v/v) BBuE or RME (B10, B20, B30, and B40).Tests were conducted on selected physicochemical properties of the obtained fuels. "B" fuels prepared with BBuE and DF were shown to have more favorable fuel properties than those obtained from RME and DF. Fuels that are blends of BBuE and DF have slightly higher heating values, higher cetane number values, a more favorable distillation curve, lower dynamic viscosity values as a function of temperature, and marginally lower flash point values compared to the corresponding blends of RME and DF. Esters with shorter molecules have been shown to have more favorable fuel properties. [ABSTRACT FROM AUTHOR]