Search Results (218)

Hydrotreated Vegetable Oil (HVO) is one of the solutions for replacing fossil diesel with a clean and renewable fuel in compression ignition (CI) engines. This study focuses on the benefits of using HVO-fueled engines in Brazil concerning CO₂ emissions, compared with other alternatives in the Brazilian energy matrix. The analysis includes CO₂ emissions from the Brazilian diesel fleet over the last 10 years considering conventional diesel fuel, traditional biofuels, and the anticipated introduction of HVO into the Brazilian market. The proposal involves neat HVO as well as blends of fossil diesel, biodiesel, and HVO (up to 50% by vol.), these blends being more realistic for their practical deployment. Considering the Brazilian diesel fleet over the past 10 years (2015–2025), net CO₂ emissions would have been reduced by 77.4% if 100% HVO had been used, while a reduction of 54.4% would have occurred with the blend containing 50% of HVO. Moreover, the use of 100% HVO for this fleet from 2015 would lead to 366.5 and 652.4 Mton of CO₂ in 2030 and 2035, respectively, compared with 1621.5 and 2885.9 Mton if 100% fossil diesel is used. The economic analysis suggests that fuel cost savings of approximately 12 USD billion could be reached in 2035 under favorable HVO production scenarios. This is a favorable projection, with positive values for all blends and pure HVO, indicating economic feasibility. Full article

Varshavskii’s ‘Diffusion Theory’, less investigated due to its limited international visibility, can offer one of the simplest and, on the other hand, high-accuracy methods for evaluating the ignition delay of fossil fuel and biofuel droplets, including their blend. In this study, experimental pre-tests were conducted to determine pre-existing subject knowledge on stationary droplet combustion at ambient pressure and temperatures varying from 935 to 1010 K followed by simulation of droplet ignition times. The test fuels were mineral diesel (DF), RME and a 20% RME blend with DF. Simulations were performed for isobaric conditions. Using the detailed transport model and detailed chemical kinetics, the necessary rearrangements were made for the governing equations to meet the criteria for modern fuels (biodiesel, diesel, and blend). The influence of different physical parameters, such as droplet radius, or initial conditions, on the ignition delay time was investigated. The high sensitivity of the proposed methodology to experimental results was substantiated. Full article

This research work seeks to introduce eco-friendly, low-carbon, and high-octane biofuel gasoline production using a synergistic approach. Four types of high-octane gasoline, including SynergyFuel-92, SynergyFuel-95, SynergyFuel-98, and SynergyFuel-100, were generated, emphasizing the deliberate combination of petroleum-derived gasoline fractions using reformate, isomerate, and delayed coking (DC) naphtha with octane-boosting compounds—bio-methanol and bio-ethanol. A set of tests have been performed to examine the effects of antiknock properties, density, oxidation stability, distillation range characteristics, hydrocarbon composition, vapor pressure, and the volatility index on gasoline blends. The experimental results indicated that the gasoline blends made from biofuel (SynergyFuel-92, -95, -98, and 100) showed adherence to important fuel quality criteria in the USA, Europe, and China. These blends had good characteristics, such as low quantities of benzene and sulfur, regulated levels of olefins and aromatics, and good distillation qualities. By fulfilling these strict regulations, Synergy Fuel is positioned as a competitive and eco-friendly substitute for traditional gasoline. The results reported that SynergyFuel-100 demonstrated the strongest hot-fuel-handling qualities and resistance to vapor lock among all the mentioned Synergy Fuels. Finally, the emergence of eco-friendly, low-carbon, and high-octane biofuel gasoline production with synergistic benefits is a big step in the direction of sustainable transportation. Full article

With the implementation of the ISO 8217-2024 marine fuel standard, the use of high-concentration biofuels in ships has become viable. However, relatively few studies have been conducted on the effects of biofuels on cylinder lubrication performance in low-speed, two-stroke marine diesel engines. In this study, catering waste oil was blended with 180 cSt low-sulfur fuel oil (LSFO) to prepare biofuels with volume fractions of 24% (B24) and 50% (B50). These biofuels were evaluated in a MAN marine diesel engine under load conditions of 25%, 50%, 75%, and 90%. The experimental results showed that, at the same engine load, the use of B50 biofuel led to lower kinematic viscosity and oxidation degree of the cylinder residual oil, but higher total base number (TBN), nitration level, PQ index, and concentrations of wear elements (Fe, Cu, Cr, Mo). These results indicate that the wear of the cylinder liner–piston ring interface was more severe when using B50 biofuel than when using B24 biofuel. For the same type of fuel, as the engine load increased, the kinematic viscosity and TBN of the residual oil decreased, while the PQ index and the concentrations of Fe, Cu, Cr, and Mo increased, reflecting the aggravated wear severity. Ferrographic analysis further revealed that ferromagnetic wear particles in the oil mainly consisted of normal wear debris. When using B50 biodiesel, a small amount of fatigue wear particles were detected. These findings offer crucial insights for optimizing biofuel utilization and improving cylinder lubrication systems in marine engines. Full article

In this study, a response surface methodology (RSM) using a central composite design (CCD) was implemented to investigate the influence of process variables on ethyl levulinate (EL) production from the ethanolysis of waste corn cob samples, using sulphuric acid as a catalyst. The effects of four independent variables, namely, the temperature (A), the corn cob content (B), corn cob/H₂SO₄ mass ratio (C) and the reaction time (D) on the yields of EL (Y₁), diethyl ether (DEE) (Y₂) and solid residue (Y₃) were explored. Using multiple regression analysis, the experimental results were fitted to quadratic polynomial models. The predicted yields based on the fitted models were well within the experimental uncertainties. Optimum conditions for maximising the EL yield were found to be 176 °C, 14.6 wt. %, 21:1 and 6.75 h for A to D, respectively. A moderate-to-high EL yield (29.2%) from corn cob was achieved in optimised conditions, a result comparable to those obtained from model C₆ carbohydrate compounds. Side products were also produced, including diethyl ether, furfural, levulinic acid, 5-hydroxymethyl furfural, ethyl acetate, ethyl formate and water. Total unknown losses of only 5.69% were reported after material balancing. The results suggest that lignocellulosic waste such as corn cob can be used as a potential feedstock for the production of ethyl levulinate by direct acid-catalysed ethanolysis, but that the treatment of side products will need to be considered. Full article

Biofuels, such as ethanol (CH₃CH₂OH), remain significantly underutilized globally despite their potential to mitigate environmental effects associated with fossil fuel combustion. Ethanol (ETH) can seamlessly blend with petroleum-derived gasoline, boosting its octane rating as a virtuous side effect. However, in several countries, octane number (ON) boosters such as methyl-tert-butyl-ether (MTBE) are still blended into the gasoline (also known as gas or petrol) sold in fuel stations, despite this being restricted or banned due to deleterious effects on the environment and health. Additionally, in nations overproducing naphtha from refining petroleum condensates, such as in the Middle East, investments in extra carbon chain rearrangement units can be an outlet to enhance gasoline production, since they produce high-ON streams; however, aromatic concentration becomes a limiting constraint. A discrete-event simulation algorithm combines sixteen main (primary) manufacturing variations into two secondary manufacturing and three supply chain variations, building gasoline yield and property plots over 512 gasoline production scenarios. Full article

The transition to sustainable energy systems necessitates the development of cleaner fuel alternatives for compression ignition (CI) engines, which continue to play a vital role in transportation and power generation. This study explores the potential of hybrid fuel blends comprising biofuels, hydrogen, ammonia, and synthetic fuels to enhance engine performance while minimizing environmental impact. By reviewing recent advancements, the paper analyzes the combustion characteristics, emissions behavior, and feasibility of various fuel combinations. Biofuel–hydrogen blends improve flame speed and reduce carbon emissions, while ammonia offers zero-carbon combustion when paired with more reactive fuels, like biodiesel or hydrogen. Synthetic fuels, particularly those derived from renewable sources, provide high-quality combustion with low particulate emissions. Hybridization strategies leverage the strengths of each component fuel, resulting in synergistic effects that enhance thermal efficiency, reduce greenhouse gas emissions, and support the continued use of CI engines in a carbon-constrained future. The findings indicate that with proper optimization of fuel formulations and engine technologies, hybrid fuels can play a key role in achieving sustainability goals and reducing fossil fuel dependency. Full article

Growing concern about anthropogenic climate change and the continuous increase in the energy demand have driven the need to explore new energy sources, particularly in the transportation sector. Biodiesel is one of the most widely used biofuels, but its disadvantages restrict its use in blends with conventional diesel. A better alternative is green diesel, a hydrocarbon biofuel that can be used in its pure form and is produced through the catalytic deoxygenation of vegetable oils. In this study, a NiMoAl catalyst derived from layered double hydroxides (LDHs) was synthesized and used for the catalytic deoxygenation of rapeseed oil to produce green diesel. The catalyst was characterized using IR, XRD, and BET analysis. The reactions were carried out in a batch reactor, and parameters such as the temperature, pressure, catalyst loading, and reaction time were examined. The results demonstrated that the complete conversion of rapeseed oil was achieved under optimal conditions (320 °C, 40 bar H₂, 4 wt% catalyst), with a diesel-range hydrocarbon content of over 90%. The recyclability of the catalyst was also evaluated, showing sustained activity over multiple reaction cycles while maintaining high conversion and selectivity toward hydrocarbons in the diesel range. Full article

Hybrid electric vehicles are essential in the automotive industry. Combining electric propulsion with biofuels to power the electric motor and the internal combustion engine offers enormous potential to reduce fuel consumption and polluting emissions. However, to operate efficiently, HEVs require an EMS that decides whether the vehicle is propelled by the combustion engine or the electric motor while managing power generation and the battery charge state. This work analyzes the use of biodiesel as a fuel in hybrid electric vehicles (HEVs). For this purpose, the mechanical behavior of a diesel engine was experimentally determined using a B10 blend to evaluate its power, torque, emissions, and operating behavior, such as temperatures and pressures. The engine used was a 2.5 L four-stroke with 131 hp at 3600 rpm to complete the efficiency map considering power, torque, and combustion. Finally, an energy management strategy based on an efficiency map is proposed. The results show that it is possible to use a specific operating range of the combustion engine with maximum efficiency while maintaining an optimal battery state of charge (SOC). Full article

The valorization of agri-food wastes can provide value-added products, enzymes and biofuels. For the second-generation ethanol (2G) production, pulps rich in cellulose are desirable in order to release fermentable sugars. This study investigated the homemade biosynthesis of cellulases and hemicellulases via solid-state fermentation (SSF) using sugarcane bagasse (SB) and wheat bran (WB) for the growth of endophytic fungi (Beauveria bassiana, Trichoderma asperellum, Metarhizium anisopliae and Pochonia chlamydosporia). Cocktails with high enzymatic levels were obtained, with an emphasis for M. anisopliae in the production of β-glucosidase (83.61 U/g after 288 h) and T. asperellum for xylanase (785.50 U/g after 144 h). This novel M. anisopliae β-glucosidase demonstrated acidophile and thermotolerant properties (optimum activity at pH 5.5 and 60 °C and stability in a wide pH range and up to 60 °C), which are suitable for lignocellulose saccharifications. Hence, the M. anisopliae multi-enzyme blend was selected for the hydrolysis of raw and organosolv-pretreated corn straw (CS) and corncob (CC) using 100 CBU/g cellulose. After the ethanol/water (1:1) pretreatment, solid fractions rich in cellulose (55.27 in CC and 50.70% in CS) and with low concentrations of hemicellulose and lignin were found. Pretreated CC and CS hydrolysates reached a maximum TRS release of 12.48 and 13.68 g/L, with increments of 100.80 and 73.82% in comparison to untreated biomass, respectively, emphasizing the fundamental role of a pretreatment in bioconversions. This is the first report on β-glucosidase biosynthesis using M. anisopliae and its use in biomass hydrolysis. These findings demonstrated a closed-loop strategy for internal enzyme biosynthesis integrated to reducing sugar release which would be applied for further usage in biorefineries. Full article

Several countries have cities located at elevations above 2000 m. Consequently, the internal combustion engines (ICEs) that operate there do not achieve the desired performance and emissions under these atmospheric conditions. One approach to mitigate these effects and, at the same time, address climate change is the use of biofuel–fossil fuel blends. However, ICEs must operate under a wide range of rpm to meet varying workload demands, raising concerns that these fuel blends may not be fully effective in achieving the desired performance and emission outcomes under such conditions. To address this issue, a series of experimental tests were conducted at low and high rpm of a spark-ignition (SI) ICE fuelled with bioethanol–gasoline blends in the ratios of E10, E15, E20, E40, E60, E85, and E100. The tests were conducted at 2600 m above sea level (masl) under various engine loads. The E20 and E40 blends showed outstanding performance at 2700 rpm, achieving high brake power and low emissions of CO₂ and HCs. At 4300 rpm, the E40 blend exhibited great performance because the engine produced high brake power and low emissions of CO and NOx. Based on these results, it can be concluded that bioethanol concentrations of between 20 and 40% in the blend effectively compensate for the reduced atmospheric oxygen at high altitudes, enhancing the combustion process in SI-ICEs. Full article

The current work includes experimental and numerical investigations into the effects of biodiesel (Eichhornia Crassipes) blends with different aluminum oxide nanoparticle concentrations on the combustion process in diesel engines. The experiments included measuring performance parameters and emissions tests while changing the engine speed and increasing loads. IC Engine Fluent, a specialist computational tool included in the ANSYS software (R19.0 version), was used to simulate internal combustion engine dynamics and combustion processes. All investigations were carried out using biodiesel blends with three concentrations of Al₂O₃ nanoparticles: 50, 100, and 150 ppm. The tested samples are called D100, D80B20, D80B20N50, D80B20N100, and D80B20N150, accordingly. The combustion characteristics are improved due to the catalytic effect and higher surface area of nano additives. The results showed improvements in the combustion process as the result of the nanoparticles’ addition, which led to the higher peak cylinder pressure. The increases in the peak cylinder pressures for D80B20N50, D80B20N100, and D80B20N150 about D80B20 were 3%, 5%, and 8%, respectively, at a load of 200 Nm, while the simulation found that the maximum temperature for biodiesel blends diesel was higher than that for pure diesel; this was due to the higher hydrocarbon values of D80B20. Also, nano additives caused a decrease in temperatures in the combustion of biofuels. Finally, nano additives caused an enhancement of the emissions test results for all parameters when compared to pure diesel fuel and biofuel. Full article

Energy demand is continuously increasing owing to rapid technological developments and population growth. Additionally, it has been shown that the consumption of fossil fuels contributes to the emission of gases that increase the greenhouse effect. An alternative for addressing the problems of greenhouse gas emissions and dependence on oil is to replace fossil fuels with biofuels. This article presents the combustion gas emissions and performance assessment of a used car using gasoline–bioethanol blends at concentrations free of mechanical risk to contribute information for energy transition. The tests were carried out using the mixtures E0, E5, and E10 at speeds of 1500, 2500, and 4500 rpm for the evaluation of emissions. Meanwhile, for the performance assessment, the speed was varied from 2500 rpm to 8000 rpm. The vehicle was analyzed under functional operating conditions, and no mechanical modifications were made to the alcohol mixtures. Testing was performed using a gas analyzer with non-dispersive infrared (NDIR) electroluminescence and electrochemical cells to measure the emissions, and a computerized chassis dynamometer was used to measure the torque and speed. From the results shown here, it can be concluded that the use of bioethanol at low concentrations in the range without mechanical risk, such as E0, E5, and E10, can be utilized in used cars and in functional operating conditions, improving the thermal efficiency of the engine by 2% and 1.2% with the E5 and E10 mixtures. The specific consumption increased up to 3% with the E10 mixture owing to the lower energy capacity of the mixture. Meanwhile, HC polluting emissions decreased by up to 8.44%, 20%, and 100 at speeds of 1500 rpm, 2500 rpm, and 4500 rpm, respectively. The nitrogen oxide emissions decreased by up to 5% for mixtures E5 and E10. The results presented in this article may be useful for decision making in the use of biofuels in automobiles used in the energy transition. In addition, our study can be taken as a reference for studies on cars that are more than 20 years old. Full article

Agriculture may hold the key to a sustainable future. By efficiently capturing atmospheric CO₂, we can simultaneously produce food, feed, biomass, and biofuels. For more eco-friendly soil processing practices, biofuels can replace diesel in agricultural machinery, significantly reducing the carbon footprint of crop production. Thus, biofuel production can be a sustainable solution for a future with a decreasing carbon footprint. This paper examines the possibility of replacing petroleum-based fuels with 100% biofuels to continue powering heavy-duty vehicles, where the use of electric vehicles is not the optimal solution. This study particularly focused on the operating scenario of heavy-duty engines under medium to high loads, typical of transport or soil processing in agriculture. Diesel was used as a benchmark, and each alternative, such as vegetable oil, methyl ester (B100), and methyl ester–ethanol blends (90B10E, 80B20E, and 70B30E), was tested individually. To find a sustainable fuel substitute, the goal was to identify a biofuel with a kinematic viscosity similar to that of diesel for a comparable spray process. Experimental results showed that an 80% methyl ester and 20% ethanol blend had a kinematic viscosity close to that of diesel. In addition to diesel, this blend resulted in a 48.6% reduction in exhaust gas opacity and a 6.54% lower specific fuel consumption (BSEC). The main aim of the tests was to find a 100% biofuel substitute without modifying the fuel injection systems of existing engines. Full article

This study evaluates the performance of biofuels created from triple blends of fossil diesel, sunflower or castor oil (SVOs), and 2-Ethylhexyl Nitrate (EHN), a low-viscosity, high-cetane (LVHC) solvent. EHN reduces the viscosity of SVOs to enable their use in conventional diesel engines without compromising fuel properties. The results show that the power output from these blends is similar to or greater than that of fossil diesel, with comparable fuel consumption. Furthermore, the blends significantly reduce emissions of carbon monoxide (CO) and soot, though NOx emissions are slightly higher due to the nitrogen content in EHN. However, NOx levels remain within permissible limits. The substitution of fossil diesel could be further enhanced if EHN were produced using green hydrogen and lignocellulosic biomass, making it a renewable and sustainable biofuel component. These findings support the potential of EHN/SVO biofuel blends to replace a significant portion of fossil diesel in conventional diesel engines while maintaining performance and reducing harmful emissions, except for a slight increase in NOx. Full article