Standard Diesel Research Articles

Performance, emission and combustion characteristics of biodiesel fuelled variable compression ratio engine

Experiments has been carried out to estimate the performance, emission and combustion characteristics of a single cylinder; four stroke variable compression ratio multi fuel engine fuelled with waste cooking oil methyl ester and its blends with standard diesel. Tests has been conducted using the fuel blends of 20%, 40%, 60% and 80% biodiesel with standard diesel, with an engine speed of 1500 rpm, fixed compression ratio 21 and at different loading conditions. The performance parameters elucidated includes brake thermal efficiency, specific fuel consumption, brake power, indicated mean effective pressure, mechanical efficiency and exhaust gas temperature. The exhaust gas emission is found to contain carbon monoxide, hydrocarbon, nitrogen oxides and carbon dioxide. The results of the experiment has been compared and analyzed with standard diesel and it confirms considerable improvement in the performance parameters as well as exhaust emissions. The blends when used as fuel results in the reduction of carbon monoxide, hydrocarbon, carbon dioxide at the expense of nitrogen oxides emissions. It has found that the combustion characteristics of waste cooking oil methyl ester and its diesel blends closely followed those of standard diesel.

Investigation on the Combustion and Emission Characteristics of Light-Vehicle Diesel Engine Fueled with Bio-Diesel

Tests were performed with a light-vehicle diesel engine. Four representative operating conditions in 1600r/min speed have been considered. This article compares the combustion and emission characteristics of engine fueled with Bio-diesel and standard diesel. The results showed that the ignition delay time and combustion duration shorten when fuel with bio-diesel. Bio-diesel contains more oxygen and that contribute to complete combustion of fuel. The combustion of bio-diesel fuel results higher NOx emission and lower HC、CO emissions at all operating conditions. But lower Soot emission because of bio-diesel dose not contains sulfides. At the same time, fuel consumption higher, because calorific value of bio-diesel is lower than standard diesel.

Vegetable oils and animal fats as alternative fuels for diesel engines with dual fuel operation

Vegetable oils and animal fats are applicable as fuels in standard diesel engines after having adapted the fuel system for electronically controlled dual fuel regime oil/fat–fossil diesel. In this contribution, performance and emission characteristics of the engines running on rapeseed oil, lard, or chicken fat are given and compared to those of fossil diesel and fatty acid methyl esters. The results of engine tests of these fuels show a decrease in maximum power and maximum torque in comparison to fossil diesel due to a lower energy content of triacylglycerols. These values are influenced also by a type of the engine used at testing. When compared to fossil diesel, the opacity of oil/fat based fuels is higher for an engine with lower injection pressures while it is lower for an engine with higher injection pressures. The level of both controlled and uncontrolled emissions is low for all tested biofuels and is low also for the reference fossil diesel. The results of performance and emission tests for rapeseed oil containing 3 and 6 vol.% of anhydrous ethanol are comparable to those obtained for pure oil. In this paper, practical experiences based on long-term operation of adapted vehicle fleet fuelled with oil/fat–fossil diesel are mentioned.

Exhaust Emissions of a CI Engine Operated with Biodiesel from Rapeseed Oil

In this study, biodiesel was produced from rapeseed oil and was used in a single cylinder, naturally aspirated and direct-injected diesel engine as pure biodiesel (B100) and as a blend with standard diesel fuel by 20% biodiesel to 80% diesel fuel (B20). The diesel engine emissions and some performance parameters were investigated at fully loaded engine conditions. The effects of pure biodiesel and its blend with diesel fuel on emissions of carbon monoxide (CO), nitrogen oxides (NOx), carbon dioxide (CO2), and sulfur dioxide (SO2) were clarified. Results showed that biodiesel fuel is environmentally friendly since it reduced the emissions of CO, SO2, and CO2 of engines at all speeds. Results also indicated that the pure biodiesel gave about 12% lower power and 20 to 25% higher fuel consumption as compared to diesel. However, the results were almost the same or slightly different from a blend of biodiesel-diesel and petroleum diesel fuel.

Preparation of Palm Oil Biodiesel and Effect of Various Additives on NOx Emission Reduction in B20: An Experimental Study

In this study palm biodiesel was prepared from palm oil by transesterification and subsequently different blends (B20, B30, and B40) with diesel were prepared and tested in a standard diesel engine. From the engine test result, B20 was found to be an optimum blend ratio based on engine performance and emissions. The test result shows that the exhaust emissions such as CO and HC are reduced with B20 by 28% and 30%, respectively, compared to diesel. The NOX emissions are almost the same as diesel fuel. In order to reduce NOX emission, a small quantity of different additives namely methanol, ethanol, distilled water, and diethyl ether were added to B20 and evaluated in a standard diesel engine for performance and emissions characteristics. Among all the additives with B20, B20 with 2% distilled water shows the lowest NOX emission and this may be due to lower combustion temperature compared to other additives.

Performance, emission and combustion characteristics of a variable compression ratio engine using methyl esters of waste cooking oil and diesel blends

The performance, emission and combustion characteristics of a single cylinder four stroke variable compression ratio multi fuel engine when fueled with waste cooking oil methyl ester and its 20%, 40%, 60% and 80% blends with diesel (on a volume basis) are investigated and compared with standard diesel. The suitability of waste cooking oil methyl ester as a biofuel has been established in this study. Bio diesel produced from waste sun flower oil by transesterification process has been used in this study. Experiment has been conducted at a fixed engine speed of 1500 rpm, 50% load and at compression ratios of 18:1, 19:1, 20:1, 21:1 and 22:1. The impact of compression ratio on fuel consumption, combustion pressures and exhaust gas emissions has been investigated and presented. Optimum compression ratio which gives best performance has been identified. The results indicate longer ignition delay, maximum rate of pressure rise, lower heat release rate and higher mass fraction burnt at higher compression ratio for waste cooking oil methyl ester when compared to that of diesel. The brake thermal efficiency at 50% load for waste cooking oil methyl ester blends and diesel has been calculated and the blend B40 is found to give maximum thermal efficiency. The blends when used as fuel results in reduction of carbon monoxide, hydrocarbon and increase in nitrogen oxides emissions.

A Road Forward to Improve Public Health

Air quality has improved in many countries, including the United States, during the past few decades.1,2 Importantly, these gains have translated into observable health benefits. Reductions in fine particulate matter (PM) have significantly contributed to the increase in life expectancy in the United States since the 1980s.2 However, the burden of adverse health effects caused by high levels of air pollution continues to grow throughout many regions of the world. Outdoor air pollution ranks as the 8th-leading risk factor for death among high-income countries.3 Estimates are that anthropogenic fine PM contributes to ≈3.5 million cardiopulmonary deaths globally per year.4 Perhaps not well appreciated is the reality that cardiovascular (CV) deaths likely constitute the largest portion of this mortality.1 Article see p 1721 Despite improvements in vehicular emissions, many factors related to urbanization (eg, increased commuting, traffic congestion, denser road networks) conspire to make traffic-related sources a major cause of air pollution exposures worldwide.5 Compounding this problem in modern-day societies, mounting evidence implicates traffic as a specific pollution source associated with CV morbidity and mortality.5 Therefore, a better understanding of the CV effects posed by vehicular emissions, as well as feasible means to mitigate them, is of growing public health importance. In many regions, diesel engines are a major contributor to this pollution (eg, ≈50% of cars in Europe, areas of commercial goods movement, and ports).5 Most of the standard diesel vehicles and equipment in use today produce particle emissions that are many times greater than those produced by gasoline engines, and thus they warrant ongoing attention.5 In the present issue of Circulation , Lucking et al report the results of a study investigating a host of CV responses after short-term diesel exhaust exposure.6 Their protocol used well validated …

Experimental Investigation on Performance and Emission Characteristics of Low Heat Rejection Diesel Engine with Ethanol as Fuel

Problem statement: Depleting petroleum reserves on the earth and increasing concerns about the environment leads to the question for fuels which are eco-friendly safer for human beings. The objective of present work was to investigate the effect of coating on piston, cylinder head and valves of a Diesel engine on the performance and emission characteristics of exhaust gases using wet ethanol (5% water) as a fuel. Approach: In this study the effect of Zirconia coating on the performance and emission characteristics of diesel engine was investigated using ethanol as sole fuel. For this purpose the cylinder head, valve and piston of the test engine were coated with a partially stabilized Zirconia of 0.5 mm thick by the plasma spray coating method. For comparing the performance of the engine with coated components with the base engine, readings were taken before and after coating. To make the diesel engine to work with ethanol a modification was done. Results: The engine’s performance was studied for both wet ethanol and diesel with and without Zirconia coating. Also the emissions values are recorded to study the engine’s behavior on emissions. Satisfactory performance was obtained with Zirconia coating compared with a standard diesel engine. The brake thermal efficiency was increased up to 1.64% for ethanol with coating and there was a significant reduction in the specific fuel consumption. The NOx, CO and HC emissions in the engine exhaust decreases with coating. Conclusion: Using ethanol as sole fuel for a LHR diesel engine causes an improvement in the performance characteristics and significant reduction in exhaust emissions.

Premium quality renewable diesel fuel by hydroprocessing of sunflower oil

Hydroprocessing of neat sunflower oil was carried out at 360–420 °C and 18 MPa over a commercial hydrocracking catalyst in a bench scale fixed bed reactor. In the studied experimental range, products consisted exclusively of hydrocarbons that differed significantly in composition. While the concentration of n-alkanes exceeded 67 wt.% in the reaction products collected at 360 °C, it decreased to just 20 wt.% in the product obtained at 420 °C. Consequently, the fuel properties of the latter product were very similar to those of standard (petroleum-derived) diesel fuel. Particularly, it exhibited excellent low-temperature properties (cloud point −11 °C; CFPP −14 °C). Reaction products obtained at 400 and 420 °C were blended into petroleum-derived diesel fuel in three concentration levels ranging from 10 to 50 wt.% and the fuel properties of these mixtures were evaluated. Diesel fuel mixtures containing the product of sunflower oil hydrocracking at 420 °C showed very good low-temperature properties including cloud point (−8 °C) and CFPP (−15 °C) that was further lowered to −25 °C due to addition of flow improvers.

The significance of vehicle emissions standards for levels of exhaust pollution from light vehicles in an urban area

This paper addresses the research question “Are more stringent exhaust emissions standards, as applied to light vehicle type approval, resulting in reduced vehicle pollution in an urban area?” The exhaust emissions of a sample of over fifty thousand road vehicles operating in London were measured using roadside remote sensing absorption spectroscopy techniques (infrared and ultraviolet), combined with Automatic Number Plate Recognition for vehicle identification. Levels of carbon monoxide (CO), hydrocarbons (HC), nitric oxide (NO), and smoke (particulate) exhaust emissions are reported by vehicle class, fuel type, and Euro emissions standard. Emissions from petrol cars of each pollutant were all observed to display a statistically significant reduction with the introduction of each successive Euro emissions standard from Euro 1 onwards. However, Euro 2 diesel cars were observed to emit statistically higher rates of NO than either Euro 1 or Euro 3 standard diesel cars. The study also confirms the continuing ‘dieselisation’ of the UK passenger car fleet. Mean NO emissions from Euro 4 diesel cars were found to be 6 times higher than Euro 4 petrol cars, highlighting the need to develop a sound understanding of the current and future ‘in-use’ emissions characteristics of diesel vehicles, and their influence on local air quality. Smoke emissions from TXII London taxis (black cabs) were found to be statistically higher than either earlier TX1 or later TX4 model variants, with possible implications for local air quality policy interventions such as maximum age limits for taxis.

The Air Pollution Exposure Laboratory (APEL) for controlled human exposure to diesel exhaust and other inhalants: characterization and comparison to existing facilities

Objective: The Air Pollution Exposure Laboratory (APEL) was designed for the controlled inhalation of human subjects to aged and diluted diesel exhaust (DE) to mimic “real-world” occupational and environmental conditions.Methods: An EPA Tier 3-compliant, 6.0 kW diesel generator is operated under discrete cyclic loads to simulate diesel on-road emissions. The engine accepts standard ultra-low sulfur diesel or a variety of alternative fuels (such as biodiesel) via a partitioned tank. A portion of raw exhaust is drawn into the primary dilution system and is diluted 9:1 with compressed air at standard temperature (20°C) and humidity (40%) levels. The exhaust is further diluted approximately 25:1 by high efficiency particulate air (HEPA)-filtered air (FA) and then aged for 4 min before entering the 4 × 6 × 7-foot exposure booth. An optional HEPA filter path immediately proximal to the booth can generate a particle-reduced (gas-enriched) exposure. In-booth particulate is read by a nephelometer to provide an instantaneous light scattering coefficient for closed-loop system control. A Scanning Mobility Particle Sizer and multi-stage impactor measures particle size distribution. Filter sampling allows determination of sessional average concentrations of size-fractionated and unfractionated particulate oxidative potential, elemental carbon, organic carbon and trace elements.Results: Approximately 300 μg/m3 PM2.5 is routinely achievable at APEL and is well characterized in terms of oxidative potential and elemental components.Conclusion: APEL efficiently creates fresh DE, appropriately aged and diluted for human experimentation at safe yet realistic concentrations. Description of exposure characteristics allows comparison to other international efforts to deepen the current evidence base regarding the health effects of DE.

Hydroprocessing of Fischer–Tropsch biowaxes to second-generation biofuels

Upgrading of Fischer–Tropsch (FT) biowaxes to second-generation biofuels via hydroprocessing is the final step for increasing the fuel amount of the overall biomass conversion route: gasification of lignocellulosic biomass, FT synthesis, and hydroprocessing. The typical FT product portfolio consists of high molecular weight paraffinic waxes as the main product and FT fuels in the diesel and naphtha boiling range. OMV's objective and contribution to the project focus on achieving coprocessing of FT biowaxes with fossil feedstock using existing hydrotreating plants of crude oil refineries. Various test runs have been examined with a conventional refining catalyst under mild conditions (380–390°C, 5.8 MPa; WHSV, 0.7–1.3 h−1) in a pilot plant. Pure FT biowax is converted to gases, fuels, and an oil/waxy residue in a fixed-bed reactor with a porous catalyst layer technology. The presence of hydrogen in the reaction chamber reduces the fast deactivation of the catalyst caused by the formation of a coke layer around the catalyst particle surface and saturates cracked hydrocarbon fragments. Another approach is the creation of synthetic biodiesel components with excellent fuel properties for premium fuel application. Basically, premium diesel fuel differs from standard diesel quality by cetane number and cold flow properties. Hydroprocessed synthetic biodiesel (HPFT diesel) has compared to conventional diesel advantages in many aspects. Depending on the catalyst selected, premium diesel quality can be obtained by shifting cold flow operability properties of HPFT fuels to a range capable even under extreme cold conditions. In addition, a high-quality kerosene fraction is obtained to create bio jet fuels with an extremely deep freezing point, as low as −80°C. The isomerization degree, as well as the carbon number distribution of high paraffinic profile, and the branching degree have a major impact on the cold flow properties and cetane number. FT diesel has, compared to HPFT diesel, a slightly higher derived cetane number (DCN > 83) and a cloud point of −9°C, whereas HPFT diesel reaches values as low as −60°C. Although the HPFT naphtha obtained consists of high amounts of isoparaffins, the RON/ MON values are comparable to fossil straight-run naphtha. The reason is that the branching degree of isoparaffins from the naphtha fraction is not sufficiently high enough to reach the typical octane number values of gasoline products delivered at filling stations. Assuming the goal of launching a premium biodiesel or biokerosene fuel to the market, these hydroprocessed synthetic biofuels from FT biowaxes are ideal blending components.

147 汎用小型ディーゼル機関を用いた植物油-軽油-エマルジョン燃料の燃焼特性(熱工学,一般講演)

147 汎用小型ディーゼル機関を用いた植物油-軽油-エマルジョン燃料の燃焼特性(熱工学,一般講演)

Deposition of carbonaceous species over Ag/alumina catalysts for the HC-SCR of NOx under lean conditions: a qualitative and quantitative study

The deposition of carbonaceous species on fresh and aged Ag/Al2O3 catalysts used for the selective catalytic reduction of NOx (HC-SCR) was investigated by a combination of analytical techniques including SEM-EDXA, nitrogen physisorption, GC-MS and TGA. Time-on-stream (TOS) experiments were carried out to determine the level of deactivation over the catalysts. Short-term deactivation was monitored with a MicroGC with a short retention time. In addition, long-term deactivation was also investigated. Hexadecane, a paraffinic component that can be produced by decarboxylation and/or decarbonylation of natural oils and fats, and a standard Finnish commercial diesel fuel were used as the reducing agents. Finally, the influence of hydrogen on the carbonaceous deposition over the catalyst was also investigated. The NO-to-N2 activity improved in the temperature range 200–500 °C as hexadecane and H2 were used as reducing agents. In the case of commercial diesel fuel, a similar positive effect of H2 on the activity was also observed, however, at somewhat higher temperature, e.g., 350–500 °C. The results from the qualitative and quantitative analyses of the carbon deposits on the catalysts are presented and discussed. Indications of decreased activity over the catalyst were found, especially at low temperatures (<350 °C). Nevertheless, only small amounts of carbon were found on the catalytic surface. It is suggested that the deactivation phenomenon could not only be attributed to the deposition of carbonaceous species on the catalysts surface but the dependence of the adsorption kinetics of the reacting species as a function of temperature and partial pressure should also be carefully taken into account.

408 汎用小型ディーゼル機関を用いた植物油-軽油-エマルジョン混合燃料の燃焼特性(応用熱工学II)

408 汎用小型ディーゼル機関を用いた植物油-軽油-エマルジョン混合燃料の燃焼特性(応用熱工学II)

MEASUREMENTS OF DIESEL SPRAY DYNAMICS AND THE INFLUENCE OF FUEL VISCOSITY USING PIV AND SHADOWGRAPHY

The effect of fuel viscosity on diesel spray droplet size and velocity is investigated in a high-pressure chamber using laser diagnostics. Particle image velocimetry (PIV) is used for the investigation of droplet velocities. Shadowgraphy employing a long-distance microscope is used for determining droplet sizes and for imaging the spray form near the nozzle exit. Double-frame microscopic shadowgraph images are also used for droplet velocity validations using particle tracking velocimetry (PTV) and micro PIV. Velocity measurements from PTV and PIV analysis of microscopic shadowgraphy measurements provide a favorable comparison with PIV results using laser sheet illumination. Two fuels of different viscosity are investigated. One is standard automotive diesel fuel. The other is a mixture of 75% canola oil and 25% automotive diesel. The mean spray penetration and angle are similar for the two fuels. Measured droplet sizes and velocities increase significantly with increased fuel viscosity. Spray density limits the axial domain that can be imaged for droplet size and velocity measurements. For light sheet PIV, diesel fuel, having the smaller droplets and thus higher optical density, is the most limited. For 75% canola fuel, larger droplets are formed due to the higher fuel viscosity, providing clearer images for the PIV algorithm. Microscopic shadowgraph images near the nozzle exit show the existence of Mach waves and the growth of shear layer instabilities. The origins of shot-to-shot variability and droplet clustering are illustrated and discussed.

Influence of biofuels on the internal flow in diesel injector nozzles

In this paper, the behavior of the internal nozzle flow of a standard diesel fuel has been compared against a biodiesel fuel (soybean oil) at cavitating and non-cavitating conditions, using a homogeneous equilibrium model. The model takes into account the compressibility of both phases (liquid and vapour) and use a barotropic equation of state which relates pressure and density to calculate the growth of cavitation. Furthermore, turbulence effects have been introduced using a RNG k - ε model. The comparison of both fuels in a real diesel injector nozzle has been performed in terms of mass flow, momentum flux, effective velocity at the outlet and cavitation appearance. The decrease of injection velocity and cavitation intensity for the biodiesel noticed by numerical simulation at different injection conditions, predict a worse air–fuel mixing process.

Optimization of Engine Operating Parameters for Turpentine Mixed Diesel Fueled DI Diesel Engine Using Taguchi Method

The present investigation used Turpentine; a volatile fraction of pinus resin as an alternate fuel for diesel fuel. Generally, turpentine possesses moderate cetane number which is not sufficient to operate existing diesel engine. However, this could be admissible along with diesel fuel in the form of blends. Keeping this in mind experiments have been conducted using blends of turpentine and diesel fuel to study its replaceability, performance and emission behaviour. As the investigation involves three parameters such as blend proportion, injection timing and injection pressure, a simultaneous optimisation method called Taguchi was used in the work. This method requires fewer numbers of trials for fixing optimum levels. This is the primary advantage of this method. As per this method nine trials were experimented and its results were used for optimisation. In addition, an ANOVA was also performed for the parameters to evaluate its percentage contribution over the desired output. The results of the taguchi experiment showed that the 40T blend (40% turpentine and 60% diesel) performed better at 29°BTDC injection timing and at 180 bar injection pressure than other blends and had a capacity to cold start the engine. Using the optimum levels, a full range experiment was also conducted using 40T blend to compare its performance and emission behaviour with standard diesel operation. The results of the full range experiment showed that the 40T blend offered approximately 2.5% higher brake thermal efficiency than diesel baseline operation without much worsening the exhaust emission.

Impact of biodiesel bulk modulus on injection pressure and injection timing. The effect of residual pressure

As the demand for energy rises fossil fuel reserves are depleted daily, increasing the interest in alternative fuels. Biodiesel is one of the best candidates in this class and its use is expected to expand rapidly throughout the world. Numerous researchers have been investigating how biodiesel affects combustion, pollutant formation and exhaust aftertreatment. There is general agreement that its combustion characteristics are similar to those of standard diesel fuel, except for a shorter ignition delay, a higher ignition temperature, and greater ignition pressure and peak heat release. Engine power output is similar with both fuels. As regards emissions, reductions in particulate matter (PM) and carbon monoxide (CO) and increases in nitrogen oxides (NOx) are described with most biodiesel blends. The latter is referred to as the ‘biodiesel NOx effect’. The vast majority of researchers who explored the effect of biodiesel did so in mechanical injection engines. They found that the primary mechanism by which biodiesel increases NOx emissions is by an inadvertent advance in the start of injection timing, caused by a higher modulus and viscosity. However, more recent studies show that NOx emissions also increase in biodiesel-fuelled common rail engines, and that in some cases they actually decrease in engines with mechanically controlled fuel injection systems. This cannot be explained solely by differences in compressibility and remains an open question. The present study provides a contribution to the discussion in this field by describing a new method to evaluate the injection advance in engines with mechanically controlled pumps. The experimental data show that the advances in the start of injection timing, using biodiesel rather than mineral diesel, are smaller than those calculated with standard methods and may even not occur at all, depending on injection system design. In addition, they demonstrate that, contrary to common belief, injection pressure does not always increase when using biodiesel. These data may help explain why some researchers have found similar or even reduced NOx emission also with mechanical injection systems.

Characteristics of a tractor engine using mineral and biodiesel fuels blended with rapeseed oil

One of the most unfavourable characteristics of crude vegetable oil when used as the fuel is the high viscosity. To improve this weakness, oil can be blended with mineral diesel or biodiesel fuels. This study was designed to evaluate how the use of mineral diesel or biodiesel blend with cold pressed rapeseed (Brassica napus) oil affects the engine power, torque and fuel consumption. A tractor equipped with direct injection, water cooling system and three-cylinder diesel engine was used for the experiment. Fuels used were standard diesel fuel (diesel), rapeseed oil methyl ester - biodiesel (B100) and their mixtures with 10, 30 and 50 vol. % of cold pressed rapeseed oil (RO). Increased portion of RO in diesel fuel blends had almost no effect on the torque measured on the tractor PTO shaft; it however decreased the maximal power. Fuel blends with B100 and rising RO content (up to 50%) gave a positive correlation with maximal torque and power. By increasing the portion of RO from 0 to 50%, the minimal specific fuel consumption increased by 6.65% with diesel and decreased by 2.98% with B100 based fuel.