Hydrotreated Vegetable Oil Research Articles

Use of Artificial Neural Network to Develop Surrogates for Hydrotreated Vegetable Oil with Experimental Validation in Ignition Quality Tester

<div>This article presents surrogate mixtures that simulate the physical and chemical properties in the auto-ignition of hydrotreated vegetable oil (HVO). Experimental investigation was conducted in the Ignition Quality Tester (IQT) to validate the auto-ignition properties with respect to those of the target fuel. The surrogate development approach is assisted by artificial neural network (ANN) embedded in MATLAB optimization function. Aspen HYSYS is used to calculate the key physical and chemical properties of hundreds of mixtures of representative components, mainly alkanes—the dominant components of HVO, to train the learning algorithm. Binary and ternary mixtures are developed and validated in the IQT. The target properties include the derived cetane number (DCN), density, viscosity, surface tension, molecular weight, and volatility represented by the distillation curve. The developed surrogates match the target fuel in terms of ignition delay and DCN within 6% error range. This investigation will be of value to developing high-fidelity models to investigate HVO combustion and spray behavior. This will be beneficial to researchers advancing the design and development of compression ignition engines to efficiently operate on renewable fuels such as HVO.</div>

Long-term storage stability of incorporated hydrotreated vegetable oil (HVO) in biodiesel-diesel blends at highland and coastal areas

This paper reports an investigation on the long-term storage stability of high percentage and reformulated biodiesel-diesel blends for the success of renewable energy initiatives. This study mainly focuses on the Indonesian context, where the mandated B30 biodiesel faces stability and hygroscopicity challenges. A novel approach incorporated hydrotreated vegetable oil (HVO) to mitigate instability while increasing the biodiesel percentage and was analyzed during storage stability over six months in highland and coastal areas. A comprehensive analysis evaluates physicochemical properties, including water content, kinematic viscosity, total acid number, oxidation stability, and microbial growth. Based on the results, biodiesel-diesel blends (B30, B40, and B30D10) revealed robust stability and quality under highland and coastal conditions. Acid numbers exhibited a slight upward trend during storage but stayed within specified limits, emphasizing limited oxidative changes. Oxidation stability surpassed standard limits for blends, highlighting the blends' resistance to oxidation, even in higher concentrations. Water content increased over time, reflecting biodiesel's hygroscopic nature, but all blends met diesel fuel standards after 6 months. Furthermore, the investigation provided valuable insights into biodiesel-diesel blends' stability, quality, and potential enhancements, contributing to informed decision-making in fuel formulation and quality control.

Elastomer-Based Sealing O-Rings and Their Compatibility with Methanol, Ethanol, and Hydrotreated Vegetable Oil for Fueling Internal Combustion Engines.

Green methanol, ethanol, and diesel-based hydrotreated vegetable oils are some of the renewable liquid fuels that show satisfactory performance in diesel engines. A notable advantage of these fuels is that they are renewable and do not require significant modifications in the existing engines for successful operation. Suitable fuel systems, especially their material compatibility, remain unresolved, and therefore, it is a weak link in their large-scale adaptation. Elastomer-based sealing O-rings lose their mechanical properties after a short exposure time to these fuels, adversely impacting their functionality. This research study evaluated the long-term material compatibility of different elastomer-based sealing materials by immersing the O-rings in these test fuels (hydrotreated vegetable oil, methanol, ethanol, and diesel) for different time intervals (i.e., up to 15 months). The material compatibility was assessed mainly by investigating these changes in various mechanical properties of these O-rings, namely tensile strength (ΔTs), elongation at break (ΔEb), Shore A hardness (ΔH), and mass (ΔM). The degradation of mechanical properties was studied and analyzed during the immersion interval from 0.9 to 15.2 months and compared with O-rings kept in a normal atmosphere. It was noted that individual fuels affect various mechanical properties significantly. In a short interval of 0.9 months (28 days), significant changes in the mechanical properties of the sealing O-rings were observed.

Performance, Emissions, and Decarbonization of an Industrial Gas Turbine Operated With Hydrotreated Vegetable Oil

Abstract As part of Uniper's strategy for carbon neutrality in its European power generation by 2035, a Kraftwerk Union/Siemens V93.0 gas turbine (GT) in Malmö, Sweden was operated with hydrotreated vegetable oil (HVO) as a low-carbon replacement for gas oil in July 2021. Prior to HVO operation, a feasibility study was conducted including fuel comparison, flame temperature modeling, and a hazard identification study. During the two-day demonstration, GT performance was monitored using either gas oil or HVO at startup, full load, part load, and shut-down. Accredited emissions of NOx, CO, SO2, and dust were measured to allow comparison between fuels. When firing HVO, no adverse GT operations were encountered, and direct flame imaging was used to observe the successful HVO ignition process at startup. NOx emissions were nominally similar to gas oil during HVO operation. Therefore, the water injection rate for NOx control was unchanged between fuels, confirming the predictions of the flame temperature modeling. Dust, CO, and SO2 emissions reduced during HVO operation. HVO also enables significant lifecycle CO2 emissions reductions compared with fossil gas oil with ∼163 tCO2 emissions avoided in this trial. This trial provides evidence for future site fuel conversion. Further testing and monitoring is required to develop evidence regarding the long-term impact of HVO operation on fuel storage, fuel delivery, and hot gas path components. To the authors' knowledge, this trial is the first successful demonstration of HVO use in an industrial gas turbine in the world.

The Impact of RED III Directive on the Use of Renewable Fuels in Transport on the Example of Estonia

Abstract Over the past two decades, there has been an increasing use of biofuels worldwide, especially in Europe. The main objective is to reduce greenhouse gas emissions, particularly carbon dioxide (CO2), from transportation. The regulation of fuels produced from biomass and other renewable sources at the EU level is primarily governed by the Renewable Energy Directive (RED). As of today, RED III directive has come into effect, significantly altering the EU fuel market by 2030. The main change involves an increase in the share of renewable fuels in transport and the non-use of first-generation fuels. Since all EU member states are obliged to comply with the RED III directive, it is essential to assess the current status of each member state in meeting the requirements for transport fuels. Therefore, the aim of this article is to analyse the impact of the RED III directive on the use of renewable fuels in the transport sector. Specifically, it provides an overview of various RED directives’ requirements, analyses the shares of renewable fuels in fossil diesel in Estonia under different RED III compliance scenarios, and presents an overview of the situation regarding the use of renewable fuels in Estonia. The article is based on a literature review, and fuel share calculations are based on RED III directive calculation methodologies. The results of the study indicate that if the requirement for the share of renewable energy used in transport is 29 %, using only HVO (Hydrotreated Vegetable Oil) to achieve this goal would require replacing 30.3 % of diesel with HVO. In cases where there is a requirement to reduce the greenhouse gas emission intensity of fuels in the transport sector by at least 14.5 % by 2030, the volumetric share of HVO fuel must meet certain criteria based on the raw material. For example, fuel produced from residues must contain a minimal amount of biocomponents. In this context, biologically derived oil is initially used, such as in food preparation. Subsequently, after its use in food preparation, it is processed into fuel. The article also addresses cases where biogas is introduced as a renewable component in replacing diesel.

Spray Momentum Flux Novel Estimation Procedure through the Fuel Rate of Injection Using Hydrogenated Fuels with Single Hole Nozzle Diesel Injector.

Sustainable means of transport require the innovation or development of propulsive systems more respectful of the environment. Despite current criticism, modern compression-ignition engines are efficient alternatives also in light aviation and surveillance drones (such as small helicopters), as means of air transport. Currently, the improvement of the injection, air-fuel mixture formation, and combustion processes using sustainable synthetic fuels, produced from renewable raw materials or by carbon dioxide capture, is a reality. For improving the air-fuel mixture formation inside the combustion chamber, one of the key parameters is knowledge of the spray momentum flux because of its effect on the air entrainement. To measure this parameter is complex. However, the experimental determination of the fuel mass flow rate is a common procedure. The objective of this work is the proposal of a novel but robust methodology for the momentum flux estimation of fuel sprays from measurement of the rate of injection. In this work, single-hole nozzles of 115, 130, and 150 μm in diameter are studied. The implemented methodology is applied to three fuels: a diesel fuel without biodiesel, used as reference, and two sustainable synthetic fuels: a gas to liquid fuel and a hydrotreated vegetable oil. With the fuel injection rates and the simple model proposed, the spray momentum flux is estimated under different operating conditions of a common-rail injection system. The results of the spray momentum flux show a very good precision compared with those experimentally and previously obtained with similar fuels but with multihole nozzle. With the method proposed in this work, an adequate forecast of spray momentum flux is obtained in the case of not having an experimental setup that allows direct measurement of the momentum flux. This study can help investigators for fuel spray modeling with novel and renewable fuels in modern propulsive systems.

Exploring the effect of methanol and ethanol on the overall performance and substitution window of a dual-fuel compression-ignition engine fueled with HVO

All sectors where compression-ignition engines are the predominant technology are undergoing a complex change motivated by the transition to a carbon-free economy. Nevertheless, these engines, if operated under advanced combustion strategies and fueled with low carbon-intensive fuels, are a real opportunity. This work investigates the effect of two renewable short-chain alcohols (methanol and ethanol) on the performance, emissions, combustion pattern and energy substitution window of a dual-fuel engine operated at high and low loads. Diesel-like fuels include a hydrotreated vegetable oil to evaluate the potential of its high cetane number in dual-fuel mode. The work was executed in two stages. In the first, the operating parameters (EGR rate, combustion phasing) were adjusted for attaining the best compromise between engine efficiency and NOx emissions. In the second, the maximum achievable substitutions were sought, achieving higher substitution ratios than those found by others. HVO-ethanol pair led to the highest substitution (84%), although generally methanol showed superior results in NOx and thermal efficiency. HVO and high alcohol ratios broke down the existing trade-off between large and small particles, leading to a simultaneous reduction of large (more than one order of magnitude) and small (three times lower) compared to only diesel or HVO fueling.

Characterization of Hydrotreated Vegetable Oil (HVO) in a Euro 6 Diesel Engine as a Drop-In Fuel and With a Dedicated Calibration

Renewable fuels can play an important role in achieving future goals of energy sustainability and CO2 reduction. In particular, hydrotreated vegetable oil (HVO) represents one of the most promising alternatives to petroleum-derived diesel fuels. Several studies have shown that conventional diesel engines can run on 100% HVO without significant modifications to the hardware and control strategies. The current activity has experimentally evaluated the potential of HVO as a “drop-in” fuel, i.e., without changes to the original baseline calibration, comparing it to conventional diesel fuel on a 2.3-litre Euro 6 compression ignition engine.Tests revealed that HVO can significantly reduce engine-out soot (by more than 60%), HC and CO emissions (by about 40%), compared to diesel, while NOx levels and fuel conversion efficiency remain relatively unchanged under steady-state warmed-up conditions. The advantages of HVO proved to be further enhanced when the engine has not yet warmed up.Using statistical techniques of design of experiments (DoE) at three warmed-up steady-state operating points, the main engine control parameters were recalibrated to demonstrate that engine-out emissions can be further optimized with a dedicated calibration.

Performance Improvement and Emission Reduction Potential of Blends of Hydrotreated Used Cooking Oil, Biodiesel and Diesel in a Compression Ignition Engine

The positive effect of decarbonizing the transport sector by using bio-based fuels is high. Currently, biodiesel and ethanol are the two biofuels that are blended with fossil fuels. Another technology, namely, hydroprocessing, is also gaining momentum for producing biofuels. Hydrotreated vegetable oil (HVO) produced using this process is a potential drop-in fuel due to its improved physiochemical properties. This study aimed to reduce the fossil diesel content by blending 20% and 30% HVO and 5%, 10% and 15% waste cooking oil biodiesel on a volume basis. The blends were used to conduct a thorough performance examination of a single-cylinder compression ignition engine. The thermal efficiency of the engine was enhanced by the addition of biodiesel to the blend. The efficiency increased as the proportion of biodiesel in the mix increased, although it was still less efficient than diesel. The maximum improvement in thermal efficiency of 4.35% was observed with 20% blending of HVO and 15% blending of biodiesel compared with 20% blending of HVO and diesel. However, the HC (decrease of 30%), CO (decrease of 23.5%) and smoke (decrease of 21.1%) emissions were observed to be the lowest with 30% blending of HVO and 15% blending of biodiesel. A fuzzy-logic-based Taguchi method and Grey’s method were then applied to find the best blend of HVO, biodiesel and diesel. The combination of the two methods made it easier to carry out multi-objective optimization. The brake thermal efficiency (BTE), smoke and NO emissions were selected as the output parameters to optimize the HVO and biodiesel blend. The optimization study showed that 30% blending of HVO and 15% blending of biodiesel was the best blend, which was authenticated using the confirmation experiment.

Comparison of fuel properties of alternative drop-in fuels with standard marine diesel and the effects of their blends

Drop-in fuels are biofuels or synthetic fuels designated to be blended with conventional petroleum-derived hydrocarbons. These alternative fuel blends can be used without major modifications of the engine or the fuel system. Thus, the use of drop-in fuels offers the marine sector a good first opportunity to reduce the carbon footprint and other emissions. This work investigates the miscibility and compatibility of different potential drop-in fuels with standard distillate marine diesel in order to provide an initial outlook on possible use in the maritime sector based on their fuel characteristics. The five drop-in fuels Fatty acid methyl esters (FAME), Oxymethylene ether (OME), Hydrotreated vegetable oils (HVO), Fischer-Tropsch diesel (FTD) and a pyrolysis oil (HDO) were mixed at 10, 30 and 50 % with standard marine distillate diesel and the physical and chemical properties, the distillation curves and the corrosion stability as well as the storability were analysed. All drop-in fuels can be blended with DMA. Due to the chemically different composition of OME, the distillation curve of the blends significantly differs from the distillation curve of DMA, which should be taken into consideration when using these new alternative blends. Furthermore, the blends of OME and FTD show an unexpected corrosion, which is not observed in the pure drop-in fuels. This is expected to have a considerable influence on the engine operation as well as on the storage.

Research on the Performance Parameters of a Compression-Ignition Engine Fueled by Blends of Diesel Fuel, Rapeseed Methyl Ester and Hydrotreated Vegetable Oil

This research compares the air pollution (CO, CO2, HC, NOx, smoke), energy (brake-specific fuel consumption, thermal efficiency) and noise indicators of a compression ignition engine fueled by first-generation biodiesel (rapeseed methyl ester (RME)) and second-generation biodiesel (hydrogenated vegetable oils (HVO)), or conventional (fossil) diesel fuel blends. The concentration of first- and second-generation biodiesel in two-component blends with diesel fuel was up to 15% and 30% (RME15, RME30, HVO15, and HVO30); for comparison, the three-component blend of diesel fuel, HVO and RME (RME15–HVO15) was considered. The fuels’ physical and chemical properties were tested in a specialized laboratory, and the engine load conditions were ensured by the engine brake stand. Referring to ship power plants with constant-speed engines, detailed research was carried out in one speed mode (n = 2000 rpm). Studies have shown that two-component fuel blends with HVO are superior to conventional diesel fuel and two-component blends with RME in almost all cases. The HVO in fuel blends reduced fuel consumption up to 1.8%, while the thermal efficiency was close to that of fossil diesel fuel. In addition, a reduction in pollutants was observed: CO by ~12.5–25.0%; HC by ~5.0–12.0%; NOx by ~6.5%; smokiness by ~11–18% (two-component blend) and up to ~29% (three-component blend). The CO2 and noise characteristics were close to those of fossil diesel fuel; however, the trend of reduced smoke emission was clearly seen. A fundamental obstacle to the wide use of HVO can be seen, however, which is the price, which is 25–90% (depending on the EU country) higher than the price of conventional (fossil) diesel fuel.

Assessing the Environmental Impact of Eight Alternative Fuels in International Shipping: A Comparison of Marginal vs. Average Emissions

Global warming and other environmental concerns drive the search for alternative fuels in international shipping. A life-cycle analysis (LCA) can be utilized to assess the environmental impact of different fuels, thereby enabling the identification of the most sustainable alternative among the candidate fuels. However, most LCA studies do not consider marginal emissions, which are important when predicting the effects of large-scale fuel transitions. The research purpose of this study was to assess the marginal emissions of several currently available marine fuels to facilitate the identification of the most promising marine fuel. Thus, marginal and average emissions for eight marine fuels (high-sulfur fuel oil, very-low-sulfur fuel oil, marine gas oil, liquified natural gas, biomethane, biomethanol, fossil methanol, and hydro-treated vegetable oil) were compared in terms of their environmental impact. Non-intuitively, the results indicate that biofuels exhibit equally or higher marginal greenhouse gas emissions than conventionally used fuel oils (162–270 versus 148–174 kg CO2/MJ propulsion), despite their significantly lower average emissions (19–73 vs. 169–175 kg CO2/MJ). This discrepancy is attributed to the current limited availability of climate-efficient biofuels. Consequently, a large-scale shift to biofuels cannot presently yield substantial reductions in the shipping industry’s climate impact. Additional measures, such as optimized trading routes, more energy-efficient ships, and research on more climate-friendly biofuels and electro-fuels, are thus required to significantly reduce the climate footprint of shipping.

Characterization of particulate matter emissions from internal combustion engines using δ13C values: Impact of engine operation conditions and fuel type on PM10 isotopic composition

Stable carbon isotope ratio of particulate emissions from internal combustion engines (ICEs) is an important characteristic in atmospheric carbonaceous PM source studies. Long-term measurements (2009–2020) of δ13C values of commercial fuels in Lithuania were conducted to evaluate the current isotopic composition of the fuel due to the changing share of renewable energy sources (RES). In this work, we present experimental results on stable carbon isotope ratio (δ13C) in PM10 emitted by different types of ICEs (two-stroke and four-stroke), including on-road transport and non-road mobile machinery. Different driving scenarios were simulated on a test bench (idling, NEDC, different torque, and speed). At idle, the average δ13C(PM10) values of different fuel types were determined: −27.80‰ for gasoline, −28.97‰ for diesel, − 27.89‰ for biofuel-C3, and −16.95‰ for biofuel-C4. Isotopic fractionation during combustion in ICEs depended on fuel type. The magnitude of Δ13C was 3‰ for gasoline, 2‰ for diesel, 1.5‰ for biofuel-C3, and 0.6‰ for biofuel-C4. The δ13C values of ICEs-generated PM10 were found to be dependent on the amount biobased components such as hydrotreated vegetable oil (HVO) to the fuel. However, insubstantial differences were found between the δ13C of PM derived from pure diesel and from an ethanol/diesel blend (E40).

Properties and Analysis of Liquid Alternative Fuels III: Vegetable Oils and Hydrotreated Vegetable Oils

The importance of alternative fuels and biofuels is constantly growing due to energy security, sustainability, and social responsibility. This article is another in a series of review articles designed to recapitulate information on the required properties of individual alternative fuels, their testing methods, and the significance of individual analyses. This article is focused on fuels based on vegetable oils and hydrotreated vegetable oils. Rapeseed oil is a triglyceride-based fuel that can be burned in modified diesel engines. Modification of the engine consists in the inclusion of preheating of the fuel or modification of the injection system, due to the high viscosity of this fuel. Rapeseed oil and vegetable oils in general have a higher oxygen content than conventional diesel fuels, which is associated with a lower energy content than that of diesel fuels. Compared to diesel, vegetable oils have a higher density, a lower cetane number, and a significantly higher flash point and viscosity. Vegetable oils also have low oxidative stability. Physical properties monitored in rapeseed oils include density, viscosity, flash point, and calorific value. From the chemical properties, the iodine number, acidity number, water content, calcium, magnesium, sulfur, and phosphorus are monitored. From the other properties, oxidative stability, ignitability, ash content, carbonation residue, content of impurities, and appearance are monitored for rapeseed oils. HVO is a high-quality fuel for standard diesel engines. Due to the hydrocarbon character of HVO, no engine modification is required. HVO has a very high cetane number, very good low-temperature properties, optimal viscosity, high flash point, excellent oxidative stability, and a very low content of undesirable contaminants such as aromatic hydrocarbons, sulfur, nitrogen, and oxygen-containing compounds. Compared to diesel fuels, HVO has a lower density. The observed qualitative parameters and testing methods are very similar to those of conventional diesel fuel B7. The main difference lies in the modified determination of aromatic hydrocarbons.

Studies of Engine Performance and Emissions at Full-Load Mode Using HVO, Diesel Fuel, and HVO5

The aim of the study was to determine impact of commercially available hydrotreated vegetable oil (HVO) and its mixture (HVO5, where 5% (v/v) HVO and 95% (v/v) FDD) with diesel fuel (FDD) on the power, torque, fuel consumption, and exhaust gas composition of an atmospheric internal combustion diesel engine used in off-road applications. Diesel fuel was used as the comparative fuel. Testing was realized in a full-load mode on the KOHLER KDI 1903 M 3-cylinder diesel engine on a SIERRA CP-Engineering engine test bench. The AVL SESAM FTIR exhaust gas analytical system was used to determine exhaust gas emissions, while the AVL KMA Mobile fuel consumption measuring device was used to measure fuel consumption. Research showed that the lowest power and torque readings were obtained with FDD, while HVO showed a slightly higher result compared to the fossil diesel fuel. At the same time, the highest hourly fuel consumption was observed running on HVO5, while the lowest was observed with FDD. Increases in carbon monoxide (CO), carbon dioxide (CO2), and nitrogen oxide (NOx) emissions were observed for HVO5 compared to those of FDD. The CO content in emissions increased by an average of 3.0% using HVO and by an average of 36% using HVO5, but the NOx content in the emissions increased by an average of 3.0% using HVO and by an average of 8.8% using HVO5. The reduction by an average of 60% using HVO in emissions was found in the case of hydrocarbons (HC). Research confirmed that the physicochemical properties of HVO could leave an impact on the main engine performance parameters and exhaust emissions.

Smoke Formation during Combustion of Biofuel Blends in the Internal Combustion Compression Ignition Engine

The proposed changes to the legislation on diesel cars require intensification of work on the possibilities of reducing emissions of harmful substances into the atmosphere by these vehicles. The subject of experimental research included in the manuscript was the Skoda Octavia with a 1.9 TDI (turbocharged direct injection) compression ignition engine (type 1Z). Light absorption measurements of smokiness of the exhaust gases emitted after combustion of various biofuels (conventional diesel, pure hydrotreated vegetable oil, hydrotreated vegetable oil, biobutanol) and their blends with fossil diesel fuel were studied. The measured light absorption coefficient is the reciprocal of the thickness of the layer, after passing through which the light has a ten times lower intensity. Its unit is the reciprocal of the meter (1/m or m−1). The results obtained by means of a standard smokiness meter indicate that the use of biofuels or their blends, in general, reduces smoke formation.

EVALUATION OF VIBRATION AND NOISE CHARACTERISTICS OF A COMPRESSION-IGNITION ENGINE FUELLED WITH NATURAL GAS-BIODIESEL DUAL FUEL

As environmental requirements become more stringent and the planet becomes more polluted, the replacement of conventional diesel is attracting more interest. For alternative fuels, such as biodiesel and natural gas, to be used, their effects must be examined not only in terms of the engine’s environmental indicators but also in terms of engine vibrations and sound pressure. This study examined the influence of dual fuel – biodiesel and natural gas – on vibrations and sound pressure of a compression-ignition (CI) engine. Conventional diesel or hydrotreated vegetable oil biodiesel was used as a pilot fuel for gas ignition. The gaseous fuel was natural gas, which was injected into the intake manifold with different energy shares of the gaseous fuel (40%, 60% and 80%). Tests were performed at a constant engine crankshaft speed and a fixed start of pilot fuel injection of 6° BTDC while the fuel composition and engine load were changed. This experiment revealed correlations between gas energy share (GES) in liquid fuel and ecological and energy indicators of a CI engine.

Combustion, performance and emission analyses of a CI engine operating with renewable diesel fuels (HVO/FARNESANE) under dual-fuel mode through hydrogen port injection

The use of hydrogen in internal combustion engines is pointed out as an alternative to reduce greenhouse gas emissions. In applications that require high levels of torque and low engine speeds, compression ignition (CI) engines are more appropriate. However, because of the high auto-ignition temperature of hydrogen, its use in these engine types is more suitable when the dual-fuel concept is applied. This study comprehensively investigates, through experimental techniques, the use of hydrogen port-injection in a four-stroke single-cylinder CI engine operating with the renewable diesel-like fuels hydrotreated vegetable oil (HVO) and farnesane, in comparison to fossil diesel dual-fuel operation. In this sense, the present work aims to fill a gap in the literature by performing a novel analysis of dual-fuel operation with hydrogen, considering different substitution fractions, and using groundbreaking biofuels, such as HVO and farnesane. The results showed that in-cylinder pressure and temperature were increased with H2 enrichment for every pilot fuel, but green diesel fuels presented lower values than those for diesel operation. Furthermore, hydrogen port injection slightly delayed the start of combustion and increased the ignition delay, but a reduction in both premixed and diffusion combustion duration was observed. Reductions in PM, CO, and CO2 emissions were reported during H2 addition for every pilot fuel, while increased NOx was observed. Despite this increase, both HVO and farnesane decreased the emissions of this pollutant in single and dual-fuel operations, compared with fossil diesel. In addition, both renewable diesel fuels presented higher BTE than diesel for every studied H2 mass flow.

Production of transportation fuels via hydrotreating of scrap tires pyrolysis oil

The hydrotreating of scrap tires pyrolysis oil over commercial Ni-Mo/Al2O3 catalyst was researched for the best processing scheme allowing the production of high-quality alternative transportation fuels components of gasoline, jet, diesel, and marine fuel. Despite the initial high content of olefins, aromatics, sulfur, and nitrogen in pyrolysis oil, fuel components obtained by redistillation after the hydrotreating at 360 °C and 10 MPa met the majority of standard fuel specifications. Although the octane number of the naphtha fraction was lower, this fraction can be used as acomponent of the gasoline pool directly or after the catalytic reforming. Kerosene fraction can be utilized as jet fuel after the additional mild hydrotreatment or blending with hydroprocessed esters and fatty acids (HEFA) to decrease aromatics content. Diesel fraction can be blended with hydrotreated vegetable oils (HVO) to fulfill the density and cetane index specification. The bottom residue can be utilized as a low-sulfur fuel oil component in marine transportation.

Experimental analysis and life cycle assessment of green diesel (HVO) in dual-fuel operation with bioethanol

Renewable fuels have been used for years as an option for supplying energy demand in a sustainable manner. In terms of liquid fuels, hydrotreated vegetable oil (HVO) gained special attention in the last few years due to its good performance in diesel engines, low emissions and renewable aspect. At the same time, bioethanol represents another renewable option for energy supply and has been consolidated in the market for decades. Even though these biofuels are assumed to be environmentally friendly, a complete understanding of their environmental impacts should take into account several indicators, applications and geographical aspects. In this sense, this study presents a detailed Life Cycle Assessment (LCA) regarding the use of petrodiesel, HVO from palm and soybean oil and bioethanol in various operating conditions in a diesel engine, for small-scale electricity generation in stationary applications. Diesel and HVO are used as pilot fuels, while bioethanol was injected in the intake port in various Energy Fraction Ratios (EF), EF = 0%; EF = 28%; EF = 32%; EF = 40%; EF = 44%, in the so-called dual-fuel mode. The results obtained with pure HVO showed reductions in specific levels of NOx, HC, CO and particulate matter (PM) emissions of 30%, 75%, 81% and 55.3%, respectively, and 4.36% efficiency when compared to diesel. The Dual-Fuel application provided a significant reduction in CO2, NOX and PM emissions, but decreased engine efficiency by up to 9.4%. The LCA showed that the palm oil HVO has an environmental performance superior to the soybean HVO and is capable of reducing the Global Warming Potential up to 75%. Palm oil HVO reduces impacts in categories such as Terrestrial Acidification, Ozone Formation and Consumption of non-renewable resources when compared to diesel. The environmental impact of the dual-fuel operation presents a decrease in the levels of Global Warming Potential, Depletion of Fossil Resources and Ozone Formation.