Effect of advanced biofuels on WLTC emissions of a Euro 6 diesel vehicle with SCR under different climatic conditions

2021 ◽  
pp. 146808742110012
Author(s):  
A Calle-Asensio ◽  
JJ Hernández ◽  
J Rodríguez-Fernández ◽  
M Lapuerta ◽  
A Ramos ◽  
...  

Hydrotreated vegetable oil (HVO), a glycerol-derived biofuel (blended with diesel fuel at 20% v/v, Mo·bio®) and biodiesel produced through the esterification of residual free fatty acids from the palm oil industry (pure and blended with diesel fuel at 20% v/v), all of them considered as advanced biofuels as defined in the Directive EU/2018/2001, were tested in a Euro 6 diesel vehicle equipped with ammonia-SCR. Tests were carried out in a chassis dyno at warm (24°C) and cold (−7°C) ambient conditions following the Worldwide harmonized Light-duty vehicles Test Cycle (WLTC). The efficiency of the SCR when changing the fuel was also analysed. Regarding vehicle performance, fuel properties were mainly relevant at warm conditions. Because of the lower EGR rate, NOx emissions upstream of the SCR were higher at cold temperature, mainly during the low and the extra-high speed phases of the WLTC. CO and THC emissions were only important at the beginning of the cycle and at −7°C. HVO presented advantages regarding these compounds, while the worse cloud point of biodiesel led to higher emissions. As expected, engine-out NOx emissions were very sensitive to the EGR rate, HVO showing a slightly better behaviour because of its high cetane number. The SCR efficiency was mainly affected by the exhaust gas temperature, although fuel-derived effects were also significant. In fact, a more appropriate NO2/NOx ratio at the catalyst inlet for HVO and a higher hydrocarbon concentration at the low-speed phase for B20 contributed to a lower tail-pipe NOx emissions at −7°C. The oxygen content of biodiesel-based fuels (B100 and B20) led to lower particle number with respect to diesel fuel. Despite its nil aromatic content, the higher EGR rate and the extremely superior autoignition trend of HVO led to higher particle number under high engine load and warm conditions.

2014 ◽  
Vol 612 ◽  
pp. 175-180 ◽  
Author(s):  
K.R. Patil ◽  
S.S. Thipse

Diethyl Ether (DEE) is a promising oxygenated renewable bio-base resource fuel for CI engines owing to its high ignition quality. DEE has several favourable properties, including exceptional cetane number, very low self-ignition temperature, high oxygen content, broad flammability limits and reasonable energy density for on-board storage. It is a liquid at ambient conditions, which makes it attractive for fuel handling and fuel infrastructure requirements and hence, it is a compatible fuel for use in CI engine. Diethyl ether is the simplest ether expressed by its chemical formula CH3CH2-O-CH2CH3, consisting of two ethyl groups bonded to a central oxygen atom. It can be mixed in any proportion in diesel fuel as it is completely miscible with diesel fuel. It was observed that density, kinematic viscosity and calorific value of the blends decreases while the oxygen content and cetane number of the blends increases with the concentration of DEE addition. The presence of DEE increases the front end volatility of the blends and decreases boiling point in comparison to baseline diesel fuel. No significant difference was observed in the tail-end volatility of the blends. The blended fuel retains the desirable physical properties of diesel fuel but includes the cleaner burning capability of DEE.


Author(s):  
Irina Gunko

The viscosity of a fuel depends on its hydrocarbon composition. Vegetable oil is considered an alternative to diesel fuel. Its high viscosity makes it difficult to consider as a commercial diesel fuel. Vegetable oil is lipids, fatty acid esters. They have a high calorific value and contain straight hydrocarbon chains, resulting in their relatively high cetane number. Viscosity and density determine the evaporation and mixing process in an engine, as they affect the shape and type of the fuel flame, the size of the droplets formed, and how they enter the combustion chamber. Low density and viscosity provide better fuel injection; with an increase in the diameter of the droplet, its complete combustion decreases, therefore, the specific fuel consumption increases and the smoke of the exhaust gases increases. The viscosity of the fuel affects the pump flow and fuel leakage through the piston pair clearance. As the viscosity decreases, the amount of diesel fuel leaks between the plunger and bushing increases, resulting in a decrease in pump flow. Converting the engine to a fuel with a lower density and viscosity will result in burnout of the piston head, so the fuel equipment needs to be adjusted. Plunger wear is viscosity dependent. It fuel is in the range of 1.8-7.0 mm2/s, which practically does not affect the durability of modern high-speed diesel equipment. Consider using vegetable rapeseed oil as an alternative to diesel fuel. Its viscosity can be reduced by chemically converting esterification to ethyl esters. When the cheese rapeseed oil is heated to 80 °C, it will give a viscosity value similar to that of commercial diesel. The mixing system will have an operating power equivalent to that of a diesel engine when heated to 40-50 °C.


Energies ◽  
2019 ◽  
Vol 12 (11) ◽  
pp. 2034 ◽  
Author(s):  
José Rodríguez-Fernández ◽  
Juan José Hernández ◽  
Alejandro Calle-Asensio ◽  
Ángel Ramos ◽  
Javier Barba

Current policies focus on encouraging the use of renewable energy sources in transport to reduce the contribution of this sector to global warming and air pollution. In the short-term, attention is focused on developing renewable fuels. Among them, the so-called advanced biofuels, including non-crop and waste-based biofuels, possess important benefits such as higher greenhouse gas (GHG) emission savings and the capacity not to compete with food markets. Recently, European institutions have agreed on specific targets for the new Renewable Energy Directive (2018/2001), including 14% of renewable energy in rail and road transport by 2030. To achieve this, advanced biofuels will be double-counted, and their contribution must be at least 3.5% in 2030 (with a phase-in calendar from 2020). In this work, the fuel properties of blends of regular diesel fuel with four advanced biofuels derived from different sources and production processes are examined. These biofuels are (1) biobutanol produced by microbial ABE fermentation from renewable material, (2) HVO (hydrotreated vegetable oil) derived from hydrogenation of non-edible oils, (3) biodiesel from waste free fatty acids originated in the oil refining industry, and (4) a novel biofuel that combines fatty acid methyl esters (FAME) and glycerol formal esters (FAGE), which contributes to a decrease in the excess of glycerol from current biodiesel plants. Blending ratios include 5, 10, 15, and 20% (% vol.) of biofuel, covering the range expected for biofuels in future years. Pure fuels and some higher ratios are considered as well to complete and discuss the tendencies. In the case of biodiesel and FAME/FAGE blends in diesel, ratios up to 20% meet all requirements set in current fuel quality standards. Larger blending ratios are possible for HVO blends if HVO is additivated to lubricity improvers. For biobutanol blends, the recommended blending ratio is limited to 10% or lower to avoid high water content and low cetane number.


Author(s):  
Takemi Chikahisa ◽  
Yutaka Tabe ◽  
Kazushige Kikuta ◽  
A. S. M. Sayem

To design a diesel engine adapting to future exhaust gas regulation, it is important to develop a driving mode simulator which can simulate vehicle performance and exhaust emissions including after-treatment system. The combustion model for this objective must be able to simulate heat release rate, variety of emissions necessary for after-treatment simulation, and exhaust gas temperature in very short computational time. The authors have developed a diesel combustion model based on the Hiroyasu model by adding variety of modifications to minimize optimization process of the empirical constants. It was shown that the simulation results with the improvement model were in good agreement with the experimental results. By adding Tsurushima model consisting of nine reaction steps with several intermediate species, the model became available for the both combustions of spray diffusion flame and of homogeneous charge compression ignition.


2018 ◽  
Vol 26 (7) ◽  
pp. 36-57 ◽  
Author(s):  
Abdulkhodor Kathum Nassir ◽  
Haroun A. K. Shahad

The aim of this experimental work is to study the effect of nanoparticles added to diesel fuel on engine performance characteristic. Nano fuels are prepared by adding Al2O3 or TiO2, both with particle size less than 45nm of diesel fuel. Four doses of each type namely (25, 50, 100 and 150) ppm are prepared. These nanoparticles are blended with diesel fuel in varying volume fraction by the means of an electric mixer and an ultrasonicator. The Nano fuels are (DF+Al2O3) and (DF+TiO2). Physicochemical properties of nano fuels are measured and compared with these of neat diesel. The study shows that the addition of nanoparticles to diesel fuel improves its physical properties such as cetane number, thermal conductivity and viscosity. The influence of nanoparticles addition is very clear on the engine performance. The results show that the performance parameters are improved for example, brake thermal efficiency is increased from 19.4% for diesel to 21% and 25% for DF+Al2O3 and DF+TiO2 respectively, the brake specific fuel consumption (BSFC) is decreased by 8% and 20% for DF+Al2O3 and DF+TiO2 respectively, the brake specific energy consumption (BSFC) is decreased by 8% and 20% for DF+Al2O3 and DF+TiO2 respectively at 25ppm and 75% load. The exhaust gas temperature is 382°C for pure diesel while it is 417°C for DF+Al2O3 and 353°C for DF+TiO2. The peak pressure for pure diesel is 62 bar and it increases with DF+Al2O3 to 66.2 bar as for DF+TiO2 the peak pressure decreases to 57.2 bar at full load and 150ppm.                                                                


Author(s):  
Anita I. Ramírez ◽  
Sibendu Som ◽  
Lisa A. LaRocco ◽  
Timothy P. Rutter ◽  
Douglas E. Longman

There has been an extensive worldwide search for alternate fuels that fit with the existing infrastructure and would thus displace fossil-based resources. In metabolic engineering work at Argonne National Laboratory, strains of fuel have been designed that can be produced in large quantities by photosynthetic bacteria, eventually producing a heavy alcohol called phytol (C20H40O). Phytol’s physical and chemical properties (cetane number, heat of combustion, heat of vaporization, density, surface tension, vapor pressure, etc.) correspond in magnitude to those of diesel fuel, suggesting that phytol might be a good blending agent in compression ignition (CI) engine applications. The main reason for this study was to investigate the feasibility of using phytol as a blending agent with diesel; this was done by comparing the performance and emission characteristics of different blends of phytol (5%, 10%, 20% by volume) with diesel. The experimental research was performed on a single-cylinder engine under conventional operating conditions. Since phytol’s viscosity is much higher than that of diesel, higher-injection-pressure cases were investigated to ensure the delivery of fuel into the combustion chamber was sufficient. The influence of the fuel’s chemical composition on performance and emission characteristics was captured by doing an injection timing sweep. Combustion characteristics as shown in the cylinder pressure trace were comparable for the diesel and all the blends of phytol at each of the injection timings. The 5% and 10% blends show lower CO and similar NOx values. However, the 20% blend shows higher NOx and CO emissions, indicating that the chemical and physical properties have been altered substantially at this higher percentage. The combustion event was depicted by performing high-speed natural luminosity imaging using endoscopy. This revealed that the higher in-cylinder temperatures for the 20% blend are the cause for its higher NOx emissions. In addition, three-dimensional simulations of transient, turbulent nozzle flow were performed to compare the injection and cavitation characteristics of phytol and its blends. Specifically, area and discharge coefficients and mass flow rates of diesel and phytol blends were compared under corresponding engine operating conditions. The conclusion is that phytol may be a suitable blending agent with diesel fuel for CI applications.


2018 ◽  
Vol 4 (2) ◽  
Author(s):  
Soni S. Wirawan dkk

Biodiesel is a viable substitute for petroleum-based diesel fuel. Its advantages are improved lubricity, higher cetane number and cleaner emission. Biodiesel and its blends with petroleum-based diesel fuel can be used in diesel engines without any signifi cant modifi cations to the engines. Data from the numerous research reports and test programs showed that as the percent of biodiesel in blends increases, emission of hydrocarbons (HC), carbon monoxide (CO), and particulate matter (PM) all decrease, but the amount of oxides of nitrogen (NOx) and fuel consumption is tend to increase. The most signifi cant hurdle for broader commercialization of biodiesel is its cost. In current fuel price policy in Indonesia (especially fuel for transportation), the higher percent of biodiesel in blend will increase the price of blends fuel. The objective of this study is to assess the optimum blends of biodiesel with petroleum-based diesel fuel from the technically and economically consideration. The study result recommends that 20% biodiesel blend with 80% petroleum-based diesel fuel (B20) is the optimum blend for unmodifi ed diesel engine uses.Keywords: biodiesel, emission, optimum, blend


2020 ◽  
Vol 38 (5A) ◽  
pp. 779-788
Author(s):  
Marwa N. Kareem ◽  
Adel M. Salih

In this study, the sunflowers oil was utilized as for producing biodiesel via a chemical operation, which is called trans-esterification reaction. Iraqi diesel fuel suffers from high sulfur content, which makes it one of the worst fuels in the world. This study is an attempt to improve the fuel specifications by reducing the sulfur content of the addition of biodiesel fuel to diesel where this fuel is free of sulfur and has a thermal energy that approaches to diesel.20%, 30% and 50% of Biodiesel fuel were added to the conventional diesel. Performance tests and pollutants of a four-stroke single-cylinder diesel engine were performed. The results indicated that the brake thermal efficiency a decreased by (4%, 16%, and 22%) for the B20, B30 and B50, respectively. The increase in specific fuel consumption was (60%, 33%, and 11%) for the B50, B30, and B20 fuels, respectively for the used fuel blends compared to neat diesel fuel. The engine exhaust gas emissions measures manifested a decreased of CO and HC were CO decreased by (13%), (39%) and (52%), and the HC emissions were lower by (6.3%), (32%), and (46%) for B20, B30 and B50 respectively, compared to diesel fuel. The reduction of exhaust gas temperature was (7%), (14%), and (32%) for B20, B30 and B50 respectively. The NOx emission increased with the increase in biodiesel blends ratio. For B50, the raise was (29.5%) in comparison with diesel fuel while for B30 and B20, the raise in the emissions of NOx was (18%) and...


2020 ◽  
Vol 12 (12) ◽  
pp. 168781402098468
Author(s):  
Xianbin Du ◽  
Youqun Zhao ◽  
Yijiang Ma ◽  
Hongxun Fu

The camber and cornering properties of the tire directly affect the handling stability of vehicles, especially in emergencies such as high-speed cornering and obstacle avoidance. The structural and load-bearing mode of non-pneumatic mechanical elastic (ME) wheel determine that the mechanical properties of ME wheel will change when different combinations of hinge length and distribution number are adopted. The camber and cornering properties of ME wheel with different hinge lengths and distributions were studied by combining finite element method (FEM) with neural network theory. A ME wheel back propagation (BP) neural network model was established, and the additional momentum method and adaptive learning rate method were utilized to improve BP algorithm. The learning ability and generalization ability of the network model were verified by comparing the output values with the actual input values. The camber and cornering properties of ME wheel were analyzed when the hinge length and distribution changed. The results showed the variation of lateral force and aligning torque of different wheel structures under the combined conditions, and also provided guidance for the matching of wheel and vehicle performance.


2021 ◽  
pp. 146808742110072
Author(s):  
Karri Keskinen ◽  
Walter Vera-Tudela ◽  
Yuri M Wright ◽  
Konstantinos Boulouchos

Combustion chamber wall heat transfer is a major contributor to efficiency losses in diesel engines. In this context, thermal swing materials (adapting to the surrounding gas temperature) have been pinpointed as a promising mitigative solution. In this study, experiments are carried out in a high-pressure/high-temperature vessel to (a) characterise the wall heat transfer process ensuing from wall impingement of a combusting fuel spray, and (b) evaluate insulative improvements provided by a coating that promotes thermal swing. The baseline experimental condition resembles that of Spray A from the Engine Combustion Network, while additional variations are generated by modifying the ambient temperature as well as the injection pressure and duration. Wall heat transfer and wall temperature measurements are time-resolved and accompanied by concurrent high-speed imaging of natural luminosity. An investigation with an uncoated wall is carried out with several sensor locations around the stagnation point, elucidating sensor-to-sensor variability and setup symmetry. Surface heat flux follows three phases: (i) an initial peak, (ii) a slightly lower plateau dependent on the injection duration, and (iii) a slow decline. In addition to the uncoated reference case, the investigation involves a coating made of porous zirconia, an established thermal swing material. With a coated setup, the projection of surface quantities (heat flux and temperature) from the immersed measurement location requires additional numerical analysis of conjugate heat transfer. Starting from the traces measured beneath the coating, the surface quantities are obtained by solving a one-dimensional inverse heat transfer problem. The present measurements are complemented by CFD simulations supplemented with recent rough-wall models. The surface roughness of the coated specimen is indicated to have a significant impact on the wall heat flux, offsetting the expected benefit from the thermal swing material.


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