Explore the vast range of titles available.

In this study, the characteristics of diesel engines were tested with in-house produced mahua biodiesel blended with diesel and copper oxide nanoparticles (CuO NP) catalyst. The preliminary investigation used mahua biodiesel-diesel blends (M10, M20, and M30) among them M20 outperformed. Further M20 and CuO NP with concentrations of 25, 50, and 75 ppm are studied. Finally, the response surface methodology (RSM) was used to determine the appropriate NP concentration for M20. The findings showed that the blend of M20 with 60 ppm NP at 80% load had the highest desirability (0.9740), and the developed RSM model predicted engine responses with a mean absolute percentage error (MAPE) of 3.0962% to the confirmation test confirming the model’s accuracy. The optimized M20NP60 blend demonstrated superior combustion, performance and emission characteristics.

This article presents our research results on the physical-chemical and direct injection diesel engine performance parameters when fueled by pure diesel fuel and retail hydrotreated vegetable oil (HVO). This fuel is called NexBTL by NESTE, and this renewable fuel blends with a diesel fuel known as Pro Diesel. A wide range of pure diesel fuel and NexBTL100 blends have been tested and analyzed: pure diesel fuel, pure NexBTL, NexBTL10, NexBTL20, NexBTL30, NexBTL40, NexBTL50, NexBTL70 and NexBTL85. The energy, pollution and in-cylinder parameters were analyzed under medium engine speed (n = 2000 and n = 2500 rpm) and brake torque load regimes (30–120 Nm). AVL BOOST software was used to analyze the heat release characteristics. The analysis of brake specific fuel consumption showed controversial results due to the lower density of NexBTL. The mass fuel consumption decreased by up to 4%, and the volumetric consumption increased by up to approximately 6%. At the same time, the brake thermal efficiency mainly increased by approximately 0.5–1.4%. CO, CO2, NOx, HC and SM were analyzed, and the change in CO was negligible when increasing NexBTL in the fuel blend. Higher SM reduction was achieved while increasing the percentage of NexBTL in the blends.

Alternative fuel technology of third-generation biofuels in place of conventional fossil fuels is currently being witnessed at a global level. Due to its sustainability and environmental friendliness, in recent years more importance is being given to biodiesel in CI engine applications. Recent trends show that microalgae are promoted as a bio-fuel due to their inherent advantages of abundant availability of oil sources and faster growth rate with ease of cultivation. Particular species of algae such as Chlorella, Botryococcus braunii, and Scenedesmus obliquus are conventionally favored for biodiesel production as they have a prominent amount of lipids content. This review outlines the current state of experimental investigations on the use of different algae biodiesel blends with diesel for CI engines. Amongst the different algae-based biodiesel, the dual Calophyllum Inophyllum methyl ester blend (CIME20) with DEE demonstrated the maximum brake thermal efficiency (BTE) and better brake-specific fuel consumption (BSFC) of CI engines. In terms of emissions, the CO, UBHC, and smoke levels are significantly lower for algae blends in contrast to neat diesel.

In the present work, a detailed investigation of the physio-chemical characteristics of grapeseed methyl ester (GSME) obtained from winery biomass waste has been carried out to evaluate its suitability as an energy alternate, for CI engines. GSME was subjected to Gas chromatography and mass spectrometry analysis from which fatty acids compositions were determined followed by other interpretations such as carbon number, number of double bonds, etc. Two different predictive correlations were identified from the literature for predicting the properties that are considered important, for using GSME as a fuel. The predicted properties of GSME are compared with the experimental results obtained through standard ASTM procedures, for diesel, neat grapeseed oil (GSO) and GSME, respectively. Further, the influence of the structural and compositional characteristics of GSME on the physicochemical properties like density, kinematic viscosity, lower calorific value, etc. has been evaluated and found to be closer to diesel.

The present investigation provides an overview of the current technology related to the green diesel, from the classification and chemistry of the available biomass feedstocks to the possible production technologies and up to the final fuel properties and their effect in modern compression ignition internal combustion engines. Various biomass feedstocks are reviewed paying attention to their specific impact on the production of green diesel. Then, the most prominent production technologies are presented such as the hydro-processing of triglycerides, the upgrading of sugars and starches into C15–C18 saturated hydrocarbons, the upgrading of bio-oil derived by the pyrolysis of lignocellulosic materials and the “Biomass-to-Liquid” (BTL) technology which combines the production of syngas (H2 and CO) from the gasification of biomass with the production of synthetic green diesel through the Fischer-Tropsch process. For each of these technologies the involved chemistry is discussed and the necessary operation conditions for the maximum production yield and the best possible fuel properties are reviewed. Also, the relevant research for appropriate catalysts and catalyst supports is briefly presented. The fuel properties of green diesel are then discussed in comparison to the European and US Standards, to petroleum diesel and Fatty Acid Methyl Esters (FAME) and, finally their effect on the compression ignition engines are analyzed. The analysis concludes that green diesel is an excellent fuel for combustion engines with remarkable properties and significantly lower emissions.

In modern society where fossil fuel prices are increasing and environmental issues are becoming more severe, biodiesel, as a new type of clean fuel, is receiving increasing attention. Biodiesel has the advantages of renewability, environmental friendliness, and good fuel properties, demonstrating broad application prospects. However, the use of biodiesel also faces some challenges, such as higher density and kinematic viscosity, lower calorific value, etc. The application of nanoparticles in biodiesel engines helps to achieve the goal of clean fuel. In terms of fuel characteristics, nanoparticles increase the calorific value, cetane value, and flash point of the fuel, improving combustion efficiency and safety, but increasing density may affect combustion. The use of nanoparticles can promote micro explosions and secondary atomization of fuel, improve combustion characteristics, and increase cylinder pressure, heat release rate, and brake thermal efficiency while reducing fuel consumption. Nanoparticles reduce HC and CO emissions, improve combustion through higher oxygen and reaction area, and reduce incomplete combustion products. On the contrary, nanoparticles also increase CO2 emissions because better combustion conditions promote oxidation reactions. For NOX emissions, some nanoparticles lower the combustion temperature to reduce emissions, while others increase emissions. Comparison shows that all nanoparticles offer varying degrees of improvement in engine performance and emissions, but the improvement provided by TiO2 nanoparticles is significantly better than that of other nanoparticles. In the future, the synergistic effect of multiple nanoparticles should be explored to further improve performance and reduce emissions, achieving effects that cannot be achieved by a single nanoparticle.

Energy sustainability and environmental issues pose greater challenges on different primary energy sectors as the global energy demand increases and it is projected to further increase with an upsurge in population. On the other hand, energy sources from conventional fossil-based fuels are depleting, forcing explorations in challenging and difficult locations. As a result, the use of alternative fuels received dramatic consideration to substitute these conventional fuels, of which natural gas took the significant share. However, the share of natural-gas vehicles in the current vehicle market is quite small, and it is estimated to be below 5%. This paper reviews the current resource scenarios including proven and potential reserves, current production, and consumption, along with the fueling infrastructure, distribution, and storage. It also provides summary of the development of fuel-injection technologies aimed to enhance the performance of gas engines. More attention was also given to natural-gas engines and their limitations. Parameters affecting the performance and combustion of compressed natural gas (CNG) in spark-ignition (SI) engines are thoroughly assessed, among which compression ratio and injection timing play major roles in the optimization of CNG-fueled engines. Furthermore, different technologies that help close the performance gap between conventional liquid-fuel and natural-gas engines and future directions of the research are presented.

Diesel engines are extensively employed in transportation, agriculture, and industry due to their high thermal efficiency and fuel economy. However, the combustion of conventional diesel fuel is accompanied by substantial emissions of pollutants, including carbon monoxide (CO), hydrocarbons (HC), nitrogen oxides (NOx), and carbon dioxide (CO2), posing significant threats to environmental quality. Biodiesel, as a renewable and cleaner alternative fuel, can significantly reduce emissions of CO, HC, and particulate matter (PM) due to its unique molecular structure. Nonetheless, its lower calorific value and poor cold-start performance limit its application, while its high oxygen content may contribute to increased NOx emissions. To address these limitations, researchers have proposed blending biodiesel with alcohol-based fuels such as methanol, ethanol, or butanol to create synergistic combustion systems that optimize engine performance and emission characteristics. This paper systematically reviews the effects of alcohol fuels on the performance and emission characteristics of biodiesel blends in diesel engines. Studies indicate that the addition of alcohol fuels can significantly enhance engine performance by improving fuel atomization, extending ignition delay, and increasing premixed combustion efficiency. These enhancements result in higher cylinder pressure, net heat release rate (HRR), and brake thermal efficiency (BTE), while reducing brake-specific fuel consumption (BSFC) to some extent. Moreover, most studies report that alcohol fuels help reduce CO, HC, smoke, and NOx emissions but tend to increase CO2 emissions. However, some findings suggest that in certain cases, the opposite results may occur. The impact of different types of alcohol fuels on performance and emissions varies significantly, requiring a comprehensive evaluation of their properties, such as latent heat, viscosity, and oxygen content. Although the appropriate addition of alcohol fuels demonstrates substantial potential for optimizing engine performance and reducing emissions, excessive blending may lead to adverse effects, necessitating careful control of the blending ratio. Future research should consider mixing two or more alcohol fuels with biodiesel to explore synergistic effects beyond the capabilities of single alcohols. Additionally, further studies should focus on optimizing fuel compositions and emission control strategies for varying operating conditions.

Faced with the depletion of fossil fuels and increasingly serious environmental pollution, finding an environmentally friendly renewable alternative fuel has become one of the current research focuses. In order to find new alternative fuels, reduce dependence on fossil fuels, improve air quality, and promote sustainable development goals, castor biodiesel was produced through transesterification, and mixed with diesel in a certain proportion. The engine performance and emissions were compared and analyzed under fixed load and different speeds of agricultural diesel engines. Biofuel, as a fuel containing oxygen, promotes complete combustion to a certain extent. As the proportion of castor biodiesel in the mixed fuel increases, the emissions of pollutants such as CO, HC, and smoke show a decreasing trend. The lowest CO, HC, and smoke emissions were observed in the B80 blend at 1800 rpm, at 0.3%, 23 ppm, and 3%, respectively. On the contrary, the CO2 and NOx emissions of the B80 blend are higher than those of 2.7 diesel, reaching 2.5% and 332 ppm respectively at 1800 rpm. The lower calorific value and higher viscosity of biodiesel result in a decrease in BTE and an increase in the BSFC of the blends. Higher combustion temperatures at high speeds promote oxidation reactions, resulting in reduced HC, CO, and smoke emissions, but increased CO2 and NOx emissions. At high speeds, fuel consumption increases, BSFC increases, and BTE decreases. Overall, castor biodiesel has similar physical and chemical properties to diesel and can be mixed with diesel in a certain proportion for use in CI engines, making it an excellent alternative fuel.

The Reactivity Controlled Compression Ignition (RCCI) has the capability to reduce NOx and PM simultaneously without compromising thermal performance. In this experimentation, B20, B10 and diesel were utilised as high reactivity fuels (HRF) and E20, E10 and gasoline were used as Low Reactivity Fuels (LRF). The HRF injection timing was divided into two phases: start of injection (SOI1) and (SOI2). The SOI1 was maintained at 25 deg Before Top Dead Center (BTDC), while SOI2 was varied across 14, 16, 18 and 20 deg BTDC. The influence of variation of SOI2 on combustion, emission and performance characteristics on a single cylinder RCCI engine is assessed. The LRF to HRF ratio was kept about 60:40. From the experimental results, it has been found that, for advanced injection timing of SOI2, there is a reduction in CO and HC emissions, while with retarded injection timing, there is a rise in emission of NOx and smoke opacity. Brake specific fuel consumption increases for both advanced and retarded injection timings.