Rape Methyl Ester Research Articles

The investigation of auto-ignition properties of 1-butanol–biodiesel blends under various temperatures conditions

In this article, the auto-ignition properties of blends of high cetane rape methyl esters (RME) as biodiesel and 1-butanol were investigated, with 1-butanol fractions of up to 25% by volume. The tests were performed using the constant volume combustion chamber (CVCC) method to determine the combustion chamber temperature effect (between 550 °C and 650 °C) on the ignition delay (ID) and combustion delay (CD) periods of the verified blends. The research of the auto-ignition properties was complemented with the derived cetane number (DCN) and the calorific properties of the fuels tested. The results uncovered several properties relating to such blends and also showed that the periods of ID and CD increase with an increase in the 1-butanol fraction in the 1-butanol–biodiesel fuel blend (1-BBF). The work also shows that an increase in the temperature of the combustion chamber into which the fuel is supplied causes delay periods to shorten to varying degrees. For fractions of 5–25% by volume in 1-butanol, for each addition of a 5% fraction of 1-butanol, the cetane number for 1-BBF decreases by an average of 4.2 units.

A Proposed Biodiesel Combustion Kinetics Based on the Computational Fluid Dynamics Results in an Ignition Quality Tester

In this paper, five biodiesel global combustion decomposition steps are added to a surrogate mechanism to accurately represent the chemical kinetics of the decomposition of different levels of saturation of biodiesel, which are represented by five major fatty acid methyl esters. The reaction constants were tuned based on the results from the numerical simulations of the combustion process in an ignition quality tester (IQT) in order to obtain accurate cetane numbers. The prediction of the complete thermophysical properties of the five constituents is also carried out to accurately represent the physics of the spray and vaporization processes. The results indicated that the combustion behavior is controlled more by the spray and breakup processes for saturated biodiesel constituents than by the chemical delay, which is similar to the diesel fuel combustion behavior. The chemical delay and low temperature reactions were observed to have greater effects on the combustion and ignition delay for the cases of the unsaturated biodiesels. The comparison between the physical ignition delay and overall ignition delay between the saturated and unsaturated biodiesel constituents has also confirmed those stronger effects for the physical delay in the saturated compounds as compared to the unsaturated compounds. The validation of the proposed model is conducted for the simulations of two direct injection diesel engines using palm methyl ester and rape methyl ester.

Experimental investigation of the autoignition properties of ethanol–biodiesel fuel blends

Growing interest in increasing the market share of renewable fuels results from the increasing consumption of fuels in various industries, especially in road transport. Such fuels include, for example, ethanol and FAME (Fatty Acid Methyl Esters), known as biodiesel. In diesel engines, ethanol, unlike biodiesel, cannot be directly used as a pure fuel due to its very low autoignition propensity. However, due to the good autoignition properties of biodiesel, increasing attention is being paid to the fuel constitution, for example, a blend of biodiesel with ethanol additive. This way, it is possible to obtain fuel for diesel engines that are compositions of only products of plant origin. In this paper, the autoignition properties of RME (Rape Methyl Esters) and ethanol blends, with the ethanol fraction up to 25% (v/v) were examined. A constant volume combustion chamber was used in the study. Under the specified test conditions, the ignition delay period and the combustion delay period, as well as the DCN (Derived Cetane Number), were determined for the individual blends. The average and maximum pressure rise rates in the combustion chamber were also analysed. The study has shown, for example, that with an increase of ethanol fraction in biodiesel, the periods of ignition and combustion delay increase. It was also shown that in the range from 5% (v/v) to 25% (v/v) of the ethanol fraction, for every increase in the fraction of ethanol by 5% (v/v), the DCN of the biodiesel–ethanol blend is reduced by an average of 3.4 units.

Badania procesu spalania w silniku o zapłonie samoczynnym zasilanym olejem napędowym i estrami metylowymi oleju rzepakowego

W artykule przedstawiono wyniki badań procesu spalania w silniku o zapłonie samoczynnym zasilanego olejem napędowym i estrami metylowymi oleju rzepakowego z dodatkami letnim i zimowym. Celem badań była ocena, czy ze względu na właściwości procesu spalania jest uzasadnione traktowanie estrów metylowych oleju rzepakowego jako paliw zastępczych w stosunku do oleju napędowego. Badania przeprowadzano w warunkach zewnętrznej charakterystyki prędkościowej na stanowisku badawczym AVL Single Cylinder Test Bed z jednocylindrowym silnikiem badawczym o zapłonie samoczynnym AVL 5402. Wyznaczono charakterystykę zewnętrzną momentu obrotowego i sprawności ogólnej. Zbadano wartości maksymalne ciśnienia indykowanego i kąty obrotu wału korbowego odpowiadające tym wartościom. Wyznaczono wartości ekstremalne pochodnej ciśnienia indykowanego względem kąta obrotu wału korbowego. Do wyznaczenia przebiegu wielkości charakteryzujących proces spalania wykorzystano oprogramowanie CONCERTO. Zbadano wartości maksymalne temperatury czynnika, wyznaczono także kąty obrotu wału korbowego odpowiadające tym wartościom. Stwierdzono duże podobieństwo wyznaczonych charakterystyk5 dla oleju napędowego i estrów oleju rzepakowego z dodatkiem letnim, natomiast wyraźnie różnią się charakterystyki zimowej wersji biopaliwa.

Badania porównawcze właściwości użytkowych silnika spalinowego zasilanego olejem napędowym i estrami metylowymi oleju rzepakowego

W artykule przedstawiono wyniki badań porównawczych właściwości użytkowych silnika o zapłonie samoczynnym zasilanego olejem napędowym i estrami metylowymi oleju rzepakowego. Jako właściwości użytkowe silnika oceniano właściwości: energetyczne ze względu na moc użyteczną i moment obrotowy, ekonomiczne ze względu na sprawność ogólną oraz ekologiczne ze względu na emisję zanieczyszczeń. W badaniach uwzględniono estry metylowe oleju rzepakowego z dodatkami letnim i zimowym. Badania przeprowadzano w warunkach zewnętrznej charakterystyki prędkościowej na stanowisku badawczym AVL Single Cylinder Test Bed z jednocylindrowym silnikiem badawczym o zapłonie samoczynnym AVL 5402 i zespołem analizatorów spalin oraz oprzyrządowaniem sterującym pracą całego systemu. Do kompletowania oraz analizy danych wykorzystano oprogramowanie AVL PUMA. W wyniku przeprowadzonych badań stwierdzono duże różnice we właściwościach użytkowych silnika dla wersji letniej i zimowej estrów metylowych olejów roślinnych. Stwierdzono również korzystny wpływ stosowania badanych biopaliw na emisję zanieczyszczeń.

Initial dynamic development of fuel spray analyzed by ultra high speed imaging

Effects of injection pressure and fuel thermodynamic properties on near nozzle spay patterns at the start of the fuel spray were investigated with an ultra-high speed imaging technique. Ethanol (ETH), winter fuel (WIN), diesel (REF), and Rape Methyl Ester (RME) were injected from a single-hole injector at 60MPa, 90MPa and 120MPa. A long distance microscope coupled with an ultra-high speed camera (Shimadzu HPV-2) was also used. The spray structure at the start of the spray included a mushroom and a trail zone. The initial mushroom was generated by the residual fuel in the SAC volume which was responsible for the variation between the different injections. The ultra-high speed imaging revealed that delays from the start of triggering (SOT) to the emergence of liquid from the nozzle were not the same under various injection pressures for different fuels, because of their thermodynamic properties. Mushroom lengths and viscosity were closely related. RME had the longest mushroom zone while ETH had the shortest mushroom zone with no stem. At higher pressures, no ligaments were observed and the leading mushrooms were integrated into the trail zone, which can be referred to as the fully atomized region. At fully atomized regions, the increase of injection pressure did not affect spray patterns. Development of the micro cone angle during this quasi-steady stage experienced a sudden increase followed by a relatively steady stage. Injection pressure and fuel viscosity were shown to have effect on the development of spray cone angle at the opening stage.

Direct nitrous oxide emissions from oilseed rape cropping – a meta‐analysis

AbstractOilseed rape is one of the leading feedstocks for biofuel production in Europe. The climate change mitigation effect of rape methyl ester (RME) is particularly challenged by the greenhouse gas (GHG) emissions during crop production, mainly as nitrous oxide (N2O) from soils. Oilseed rape requires high nitrogen fertilization and crop residues are rich in nitrogen, both potentially causing enhanced N2O emissions. However, GHG emissions of oilseed rape production are often estimated using emission factors that account for crop‐type specifics only with respect to crop residues. This meta‐analysis therefore aimed to assess annual N2O emissions from winter oilseed rape, to compare them to those of cereals and to explore the underlying reasons for differences. For the identification of the most important factors, linear mixed effects models were fitted with 43 N2O emission data points deriving from 12 different field sites. N2O emissions increased exponentially with N‐fertilization rates, but interyear and site‐specific variability were high and climate variables or soil parameters did not improve the prediction model. Annual N2O emissions from winter oilseed rape were 22% higher than those from winter cereals fertilized at the same rate. At a common fertilization rate of 200 kg N ha−1 yr−1, the mean fraction of fertilizer N that was lost as N2O‐N was 1.27% for oilseed rape compared to 1.04% for cereals. The risk of high yield‐scaled N2O emissions increased after a critical N surplus of about 80 kg N ha−1 yr−1. The difference in N2O emissions between oilseed rape and cereal cultivation was especially high after harvest due to the high N contents in oilseed rape's crop residues. However, annual N2O emissions of winter oilseed rape were still lower than predicted by the Stehfest and Bouwman model. Hence, the assignment of oilseed rape to the crop‐type classes of cereals or other crops should be reconsidered.

Where to produce rapeseed biodiesel and why? Mapping European rapeseed energy efficiency

Rapeseed is widely used to produce biodiesel, especially in Europe. In several studies, it has been shown that there is a good potential for growing this crop across the continent. However there is still little awareness that the energy efficiency of biofuel production from rapeseed is very low. Energy efficiency can be expressed in terms of Energy Return for Energy Invested (EROEI). We mapped EROEI values for all EU countries plus Switzerland based on expected yields derived from rapeseed suitability maps. We find that EU countries produce rapeseed biofuel with EROEI values of 2.2 and lower. We suggest that plans for biofuel cropping have to be supplemented by maps of EROEI. It is not only relevant to show where rapeseed can be grown, but we should also look at where its use for bioenergy can be efficient. In the area theoretically suitable for growing rainfed rapeseed (excluding unsuitable areas and water), 37.6% of the area can produce rape methyl ester (RME) biofuel only with an energy loss. We conclude that the energy efficiency of rapeseed biodiesel is low and spatially heterogeneous, and unless there are major technological improvements in the production process, replacing fossil fuels by biofuels from rapeseed is hardly a feasible option.

Integrated well-to-wheel assessment of biofuels combining energy and emission LCA and welfare economic Cost Benefit Analysis

The present study integrates material based Life Cycle Analysis (LCA) with welfare economic Cost Benefit Analysis (CBA) to evaluate resource and environmental consequences as well as welfare consequences for society of introducing biofuels in the Danish road transport sector. The integrated method focus on fossil energy consumption, CO2 emissions and total welfare economic changes within the whole LCA flow chain comprising both production of biomass and subsequent conversion into biofuel and combustion in vehicles. With regard to consequences for fossil energy consumption a global delimitation is used whereas only CO2 emissions and welfare economic consequences within Danish borders are included in the analysis. Consequently, calculated emission and welfare economic consequences can be interpreted as the consequences for Denmark of producing and using biofuels from biomass grown on Danish farm land. The method is applied with regard to production of rape diesel (rape methyl ester, RME), 1st generation ethanol from wheat and 2nd generation ethanol based on straw. Advantages and disadvantages of the LCA based material flow approach and the welfare economic based CBA approach are discussed. The influence of uncertainties on the results is evaluated illustrating the importance of paying attention to assumptions with regard to substitution of other products and resources and with regard to their relative prices.

Aspiration toxicology of hydrocarbons and lamp oils studied by in vitro technology

Medical literature regularly reports on accidental poisoning in children after aspiration of combustibles such as lamp oils which usually contain hydrocarbons or rape methyl esters (RMEs). We aimed to analyze the toxic potential of alkanes and different combustible classes in vitro with regard to biologic responses and mechanisms mediating toxicity.Two different in vitro models were used, i.e. (i) a captive bubble surfactometer (CBS) to assess direct influence of combustibles on biophysical properties of surfactant film and (ii) cell cultures (BEAS-2B and R3/1 cells, primary macrophages, re-differentiated epithelia) closely mimicking the inner lung surface. Biological endpoints included cell viability, cytotoxicity and inflammatory mediator release. CBS measurements demonstrate that combustibles affect film dynamics, i.e. the surface tension/area characteristics during compression and expansion, in a dose and molecular chain length dependent manner.Cell culture results confirm the dose dependent toxicity. Generally, cytotoxicity and cytokine release are higher in short-chained alkanes and hydrocarbon-based combustibles than in long-chained substances, e.g. highest inducible cytotoxicity in BEAS-2B was for hexane 84.6%, decane 74% and hexadecane 30.8%. Effects of RME-based combustibles differed between the cell models. Our results confirm data from animal experiments and give new insights into the mechanisms underlying the adverse health effects observed.

Influence of Soil Cultivation Technologies and Fertilisation on Productivity and Energy Production of Arable Crops

Influence of Soil Cultivation Technologies and Fertilisation on Productivity and Energy Production of Arable Crops The influence of three soil tillage technologies and two fertilisation levels on a productivity of crops and biomass for energy use, expressed in yield, cereal units (CU), energy acquired and indicative price of energy per hectare was evaluated at the experimental fields of Research Institute of Plant Production in Piešťany during 2007-2009. The highest yield of dry matter has been identified for maize for silage 19.41 t/ha, followed by winter oilseed rape 15.77 t/ha, triticale 15.39 t/ha and winter wheat 14.08 t/ha. Conventional tillage created soil condition for higher yield of dry matter in an average 17.92 t/ha, followed by minimum soil tillage 16.27 t/ha and no-till-age technology 14.3 t/ha. Nitrogen-based fertilisation (N120) has ensured a significantly higher yield of dry matter and a higher price of acquired energy €491.1 compared with €462.1 of zero-nitrogen fertilisation. The highest yield of cereal units has been identified for maize for silage 9.01 CU, followed by winter wheat 5.21 CU, triticale 4.70 CU and winter oilseed rape 4.55 CU. Energy of maize for silage has been calculated from biogas, winter oilseed rape from rape methyl ester, straw and crop residues, and for winter wheat and triticale from ethanol and straw. Average energy storage in plant biomass of crop rotation was 222.93 GJ/ha. The highest amount of energy acquired has been identified for winter oilseed rape 342.80 GJ/ha, followed by maize for silage with 236.99 GJ/ha, winter triticale 159.39 GJ/ha and winter wheat 152.52 GJ/ha.

Origins of the debate on the life-cycle greenhouse gas emissions and energy consumption of first-generation biofuels – A sensitivity analysis approach

Available results about energy and GreenHouse Gases (GHG) balances of biofuels from Life-Cycle Assessment (LCA) or life-cycle based studies present large discrepancies and thus, may lead to contradictory policy-making measures. This work reviewed seven important European LCA studies in a sensitivity analysis approach in order to get a better understanding of the roots of such a debate for three major biofuels in European production: rape methyl ester and ethanol from wheat and sugar beet. Global trends and variability of energy and GHG balances were depicted and completed with a sensitivity analysis carried out for each methodological and data parameter, which allowed making recommendations on the carrying out of LCA in a policy-making or a biofuels comparison context. Methodological choices, and especially allocation rule, appeared as key elements for results variation with influences on balances up to 149%; system expansion approach was identified as the most relevant rule since it integrates the market potential and the environmental interest of by-products promotion, which was pointed out as a crucial point for biofuels sustainability. The influence of local specificity for cultivation data was evaluated up to 167%, which puts too large geographical coverage in question. Modelling uncertainties due to N2O emissions from soils showed influences from 17 to 46%, which represents a crucial challenge for research and for LCA results accuracy. Approximations evaluation pointed out the need to integrate agricultural machinery into the assessment. Finally, land-use issue revealed its dramatic importance for LCA results and the need to define explicit scenarios for land-use alternatives.

Carbon and nitrogen trade-offs in biomass energy production

This contribution provides an overview of carbon (CFs) and nitrogen footprints (NFs) concerning their measures and impacts on the ecosystem and human health. The adversarial relationship between them is illustrated by the three biomass energy production applications, which substitute fossil energy production applications: (i) domestic wood combustion where different fossil energy sources (natural gas, coal, and fuel oil) are supplemented, (ii) bioethanol production from corn grain via the dry-grind process, where petrol is supplemented, and (iii) rape methyl ester production from rape seed oil via catalytic trans-esterification, where diesel is supplemented. The life cycle assessment is applied to assess the CFs and NFs resulting from different energy production applications from ‘cradle-to-grave’ span. The results highlighted that all biomass-derived energy generations have lower CFs and higher NFs whilst, on the other hand, fossil energies have higher CFs and lower NFs.

Using one-dimensional modeling to analyse the influence of the use of biodiesels on the dynamic behavior of solenoid-operated injectors in common rail systems: Detailed injection system model

A combined experimental and computational investigation has been performed in order to evaluate the influence of physical properties of biodiesel on the injection process in a common-direct injection system with second generation solenoid injectors. For that purpose, after a complete characterization of the system, which involved mechanical and hydraulic characterization, a one-dimensional model has been obtained and extensively validated. Simulations have then been performed with a standard diesel and a 100% rape methyl ester (RME) biodiesel which allowed a comparison and analysis of the dynamic response of the injector to be done. Different injection strategies involving main injection and main plus post-injection have been used to explore the impact of the use of biodiesel on the performance and stability of solenoid injectors. As far as the dynamic response of the injector is concerned, the results obtained have clearly shown that the use of biodiesel affects the dynamic response of the needle, especially at low injection pressures. The behavior of the system under multi-injection strategies (main plus post-injection) has been also evaluated determining for different operating conditions (injection pressures and backpressures) the minimum dwell time between injections to assure a stable behavior in the injection process (mass flow rate). Important differences have been found between biodiesel and standard diesel in this critical parameter at low injection pressures, becoming less important at high injection pressure. Finally, a modification on the injector hardware has been proposed in order to compensate these differences.

Aspiration toxicology of hydrocarbons and lamp oils studied by in vitro technology

Medical literature regularly reports on accidental poisoning in children after aspiration of combustibles such as lamp oils which usually contain hydrocarbons or rape methyl esters (RMEs). We aimed to analyze the toxic potential of alkanes and different combustible classes in vitro with regard to biologic responses and mechanisms mediating toxicity. Two different in vitro models were used, i.e. (i) a captive bubble surfactometer (CBS) to assess direct influence of combustibles on biophysical properties of surfactant film and (ii) cell cultures (BEAS-2B and R3/1 cells, primary macrophages, re-differentiated epithelia) closely mimicking the inner lung surface. Biological endpoints included cell viability, cytotoxicity and inflammatory mediator release. CBS measurements demonstrate that combustibles affect film dynamics, i.e. the surface tension/area characteristics during compression and expansion, in a dose and molecular chain length dependent manner. Cell culture results confirm the dose dependent toxicity. Generally, cytotoxicity and cytokine release are higher in short-chained alkanes and hydrocarbon-based combustibles than in long-chained substances, e.g. highest inducible cytotoxicity in BEAS-2B was for hexane 84.6%, decane 74% and hexadecane 30.8%. Effects of RME-based combustibles differed between the cell models. Our results confirm data from animal experiments and give new insights into the mechanisms underlying the adverse health effects observed.

Potential of Greenhouse Gas Reduction Producing and Using Biodiesel from Fatty Waste

Normal 0 false false false EN-US X-NONE X-NONE st1\:*{behavior:url(#ieooui) } /* Style Definitions */ table.MsoNormalTable {mso-style-name:Table Normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri,sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Times New Roman; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Times New Roman; mso-bidi-theme-font:minor-bidi;} Resolution of climate change, economy and energy decentralization problems is related to development of biofuel use and production. An increase in biofuel use and production is to ensure the reduction in greenhouse gas emissions. Following a life cycle method comparative analysis of rape methyl ester and diesel before their use in diesel engines has indicated that in production of rape methyl ester the growing of rape seeds consumes 56% of energy whose expenditure is directly dependent on rape productivity. In order to decrease energy expenditures the use of fatty waste is expedient. It is determined that production of biodiesel from frying fats yields 1.37 MJ and 98.15 g CO 2eq. economy for one MJ of product compared to diesel. Potential of used fats methyl ester greenhouse gas reduction in the life cycle reaches 0.87 and is 27% greater that that of rape methyl ester. Used fats methyl ester meets balance criteria therefore in our country the waste collection system from food industry and catering enterprises is to be established.

Identification of ‘Carbon Hot-Spots’ and Quantification of GHG Intensities in the Biodiesel Supply Chain Using Hybrid LCA and Structural Path Analysis

It is expected that biodiesel production in the EU will remain the dominant contributor as part of a 10% minimum binding target for biofuel in transportation fuel by 2020 within the 20% renewable energy target in the overall EU energy mix. Life cycle assessments (LCA) of biodiesel to evaluate its environmental impacts have, however, remained questionable, mainly because of the adoption of a traditional process analysis approach resulting in system boundary truncation and because of issues regarding the impacts of land use change and N(2)O emissions from fertilizer application. In this study, a hybrid LCA methodology is used to evaluate the life cycle CO(2) equivalent emissions of rape methyl ester (RME) biodiesel. The methodology uses input-output analysis to estimate upstream indirect emissions in order to complement traditional process LCA in a hybrid framework. It was estimated that traditional LCA accounted for 2.7 kg CO(2)-eq per kg of RME or 36.6% of total life cycle emissions of the RME supply chin. Further to the inclusion of upstream indirect impacts in the LCA system (which accounted for 23% of the total life cycle emissions), emissions due to direct land use change (6%) and indirect land use change (16.5%) and N(2)O emissions from fertilizer applications (17.9%) were also calculated. Structural path analysis is used to decompose upstream indirect emissions paths of the biodiesel supply chain in order to identify, quantify, and rank high carbon emissions paths or 'hot-spots' in the biodiesel supply chain. It was shown, for instance, that inputs from the 'Other Chemical Products' sector (identified as phosphoric acid, H(3)PO(4)) into the biodiesel production process represented the highest carbon emission path (or hot-spot) with 5.35% of total upstream indirect emissions of the RME biodiesel supply chain.

Consequential life cycle assessment of the environmental impacts of an increased rapemethylester (RME) production in Switzerland

Arable land is a constrained production factor – particular in Switzerland. Merely 45% of the consumed crops are produced domestically. Hence, the additional cultivation of rape for producing methyl ester is assumed to substitute crops used for food production. Consequently, Switzerland has to face the decision either to use the arable land for food production and import fuels or to produce fuel from rape and import the displaced food. Using Consequential Life Cycle Assessment (CLCA), the environmental consequences have been assessed if rape for energetic utilization substitutes rape used as edible oil or barley used as animal fodder. The study shows, that displacing food production by RME production in Switzerland can reduce total GHG emissions, when GHG-intense soy meal from Brazil is substituted by rape and sunflower meal, which is a co-product of the vegetable oil production. On the other hand, an increased production of vegetable oils increases various other environmental factors, because agricultural production of edible oil is associated with higher environmental impacts than the production and use of fossil fuels. In summary, the environmental impacts of an increased RME production in Switzerland rather depend on the environmental scores of the marginal replacement products on the world market, than on local production factors. ► Consequential environmental impacts of an increased RME production are assessed. ► Indirect consequences have a significant effect on the environmental impacts. ► GHG emissions are particularly affected by direct and indirect land use change. ► Total environmental impacts by the increased production of vegetable oil.

RESEARCH INTO THE QUALITY OF FUELS AND THEIR BIOCOMPONENTS

The article provides a closer look into the quality properties of fuels, analyses the merits and demerits of using biocomponents in petrol and diesel and overviews the ways of improving the quality of fuels. Work carried out by the authors covers the determination of the basic quality properties (density, kinematic viscosity and flash point) of petrol, diesel, methanol, ethanol, buthanol as well as rape methyl and rape ethyl esters. The paper investigates how these qualities influence the operational performance of the engine and puts forward the age‐dependence analysis of diesel quality properties.

Experimental Study of Biodiesel Blends’ Effects on Diesel Injection Processes

This paper presents an experimental comparison of three biodiesel blends on DI diesel injection process using a standard injection system derived from a 4-stroke DI commercial diesel engine. Specifically, this work relies on several experiments carried out over a commercial diesel fuel, with 5.75% of rape methyl ester called B5, another with 30% of RME (B30), and a pure rape methyl ester fuel (called RME). Analyses on injection rate shape, spray force, spray tip penetration, and cone angle in nonevaporative conditions have been performed and studied to compare the effect of those different fuels over the injection process. A better understanding of injection process will be useful to achieve a better comprehension of mixing process which determines combustion and emissions in a compression ignition engine. It is well-known that fuel properties like density or kinematic viscosity are higher in vegetable oils and strongly affect how injection system operates. An increase in the hydraulic delay and a higher mass flow rate have been observed in injection rate measurements when using biodiesel; macrovisualization showed that the biodiesel fuel has slightly longer penetration and narrower cone angle that leads to smaller spray volumes.