Diesel Biodiesel Ethanol Research Articles

Corrosion Behaviour of Carbon Steel in Biodiesel–Diesel–Ethanol (BDE) Fuel Blend

The biodiesel–diesel–ethanol blend represents an important alternative fuel for diesel engines; however, changes in the fuel composition and the introduction of new alternative fuel often results in corrosion and degradation of the automobile fuel system parts. In this present study, the corrosion behavior of carbon steel in B20D70E10 (biodiesel 20%, diesel 70% and ethanol 10%) fuel blend was studied by static immersion at room temperature and 60 °C. The effect of B20D70E10 fuel blend on corrosion rate, morphology of corrosion products, and chemical structure of carbon steel were studied. In addition, the change of fuel properties, namely, total acid number, density, viscosity, calorific value, flash point, and color changes were also investigated. Moreover, fuel compositional changes, such as water content and oxidation product level in the fuel blends were examined. The results showed that the degradation of fuel properties and corrosion rate of carbon steel in B20D70E10 are lower than neat biodiesel (B100), whereas slightly higher than petro-diesel (B0)

Effect of Cerium Oxide Nanoparticles and Carbon Nanotubes as fuel-borne additives in Diesterol blends on the performance, combustion and emission characteristics of a variable compression ratio engine

An experimental investigation is carried out to establish the performance, combustion and emission characteristics of a variable compression ratio engine using Cerium Oxide Nanoparticles and Carbon Nanotubes as fuel-borne nanoparticles additives in Diesterol (diesel–biodiesel–ethanol) blends. As Diesel and Ethanol are immiscible, Castor oil biodiesel is used as an additive which acts as a bridging agent to prevent the phase separation. Stability studies are carried out using Cerium Oxide Nanoparticles (CERIA) and Carbon Nanotubes (CNT) each 25, 50, 100ppm in the Diesterol blends subjected to high speed mechanical agitation followed by ultrasonic bath stabilization. It is observed that the blends are stable which are suitable for performance test on the compression ignition engine. Studies on the performance, combustion and emission characteristics are carried out on a variable compression ratio engine using the stable Diesterol–CERIA–CNT blends under various loading conditions at an optimum compression ratio of 19:1 to estimate the emission reduction potential of CERIA and CNT as catalyst in Diesterol blends. The addition of CERIA and CNT in Diesterol blend increases the cylinder gas pressure when comparing with the neat Diesterol blends. The Carbon Nanotubes act as a catalyst to accelerate the burning rate which results in decreased ignition delay and cause for the lower heat release rate and advancement of the peak heat release rate. The Cerium Oxide Nanoparticles act as an oxygen donating catalyst which provides oxygen for the oxidation of carbon monoxide and absorbs oxygen for the reduction of nitrogen oxides. The activation energy of Cerium Oxide acts to burn off carbon deposits within the engine cylinder at the wall temperature and helps to prevent the deposition of non-polar compounds on the cylinder wall resulted in significant reduction of hydrocarbon and smoke emissions. The combined effect of CERIA and CNT as fuel-borne nanoparticles additives in the Diesterol fuel blend contributes for the cleaner combustion and significantly reduces the harmful exhaust gas emissions.

Effects of altitude and fuel oxygen content on the performance of a high pressure common rail diesel engine

The change of intake oxygen content caused by altitude variation and the change of fuel oxygen content both affect the performance of diesel engines. In this paper, comparative experiments were performed on a high pressure common rail diesel engine fueled with pure diesel and biodiesel–ethanol–diesel (abbreviated as BED) blends with oxygen content of 2%, 2.5%, and 3.2% in mass percentage at different atmospheric pressures of 81kPa, 90kPa, and 100kPa. Moreover, in order to study the effect of different fuel blends with the same oxygen content on the performance of the diesel engine, tests were conducted on the diesel engine fueled with the BED blend and a biodiesel–diesel (abbreviated as BD) blend at 81kPa ambient pressure.The experimental results indicate that the influence of altitude variation on the full-load engine brake torque is not significant when the pure diesel fuel is used. With the increase of BED fuel oxygen content, the engine brake torque reduces. When the pure diesel fuel is used, with the increase of atmospheric pressure, the brake specific fuel consumption (BSFC) decreases. As the fuel oxygen content increases, there is no significant difference in brake specific fuel consumption of the BED blends. And the values of brake specific energy consumption (BSEC) gradually decrease. Soot emissions of the diesel engine decrease with the increase of atmospheric pressure and fuel oxygen content. The effect of soot emission reduction by increasing the oxygen content of the fuel is more significant than the effect of increasing atmospheric pressure. The effects of BD and BED fuels with basically the same oxygen content on the full-load performance, fuel economy, and soot emissions of the diesel engine are different. The BSFC and soot emissions of the BED fuel are lower than those of the BD fuel.

Investigation of CI engine emissions in biodiesel–ethanol–diesel blends as a function of ethanol concentration

In this work, ethanol was mixed with biodiesel–diesel blends and the effect of ethanol concentration on diesel emissions was investigated. Both low and high concentrations of ethanol were studied. Ethanol concentrations were varied at 3%, 5%, 15% and 25% in biodiesel–diesel–ethanol (BDE), while biodiesel and diesel concentrations were maintained equal (BDE3, BDE5, BDE15 and BDE25). Emission characteristics for biodiesel–diesel–ethanol blends were compared to baseline curves of diesel as a function of engine load.

Experimental investigation on thermal barrier coated diesel engine fueled with diesel-biodiesel-ethanol-diethyl ether blends

In the present work, diesel-biodiesel-ethanol (DBE) and diesel-biodiesel-diethyl ether (DBD) fuels are tested with normal diesel engine and the diesel engine coated with the layers of aluminum oxide (Al2O3) of 0.3 mm and yttria-stabilized zirconia of 0.2 mm. The various performance and emission parameters are analyzed and determined. The experimental work was carried out in a single cylinder water cooled engine coupled with eddy current dynamometer. The AVL make five gas analyzer and smoke meter were used to measure the different exhaust pollutants. The result shows that the brake thermal efficiency of coated engine is more than that of base diesel at high loads. The thermal barrier coated engine using fuel as diesel, biodiesel, and ethanol (TDBE) produces the lowest carbon monoxide (CO) emissions among all the fuels that are selected. In addition, it produces the lowest carbon dioxide (CO2) at higher loads. Both the thermal barrier coated engine using fuel as diesel, biodiesel, and diethyl ether (TDBD) and TDBE have higher NOx emissions among almost all the fuels used. The TDBE and TDBD have higher smoke emissions at initial loads but eventually show lower smoke emissions at higher loads. The thermal barrier coated diesel engine fueled with DBE and DBD shows an increase in engine power and specific fuel consumption, as well as significant improvements in exhaust gas emissions except NOx.

Particle size distributions from a city bus fuelled with ethanol–biodiesel–diesel fuel blends

The use of oxygenated fuels has potential to reduce the greenhouse gases and the regulated pollutant emissions from diesel engines. Apart from particulate matter and NOx emissions, the study of particle concentration and its size distribution emitted by diesel engines is gaining attention due to the harmful effects on the environment and human health. In this work, particle size distributions (PSDs) from the exhaust gas of a city bus working in real driving conditions have been measured using three different fuel blends: petroleum diesel used as reference fuel, a binary fuel blend of 7.7%v/v ethanol on diesel fuel (denoted as ED) and a ternary fuel blend (denoted as EBD) of ethanol, biodiesel and diesel fuels with 10%v/v of ethanol on a binary B30 fuel blend (30%v/v of soybean biodiesel on pure diesel fuel). For measuring the PSD, a city bus was equipped with a rotating disk diluter coupled to a dilution air thermal conditioner. The diluted gas was driven to a TSI Engine Exhaust Particle Sizer spectrometer. The main objective of this work was to evaluate the effect of the fuel on the main statistical parameters of PSD (geometric mean diameter and total concentration) during acceleration transitions in real vehicle driving operation. Compared to diesel fuel, the results showed a great reduction of particle concentration when both fuel blends were used, although the relative differences depended on the transition studied.

Tailoring key fuel properties of diesel–biodiesel–ethanol blends for diesel engine

Abstract Alternative fuel research for the profusely growing number of diesel run automotive has intensified due to environmental reasons and turmoil in petroleum market. Government initiatives all around the world, their energy policies and steps to emphasis the use of biodiesel; proved biodiesel as a number one renewable substitute for No. 2 diesel fuels. Among all biodiesel feedstock, palm oil is a potential source with higher yield rate without much fertilizer use especially in tropical region. However, the application of transesterified palm biodiesel is objected by many auto-manufacturers due to adverse effects on engine in long term operation. The aim of this study was to modify the key fuel properties of palm biodiesel which causes engine fouling in long term operation. A significant amount of work is devoted to mix biodiesel and diesel at arbitrary percentages and test engine performance. Numerous fuel additives are developed for biodiesels automotive use. In this study, chemical properties of biodiesel are tailored by ethanol and an optimum formulation is derived mathematically. Ethanol is used at a controlled proportion (6%) with palm oil methyl ester (POME) as additive to reduce the higher viscosity of POME. This optimum palm biodiesel–ethanol blend was mixed at varying proportions (i.e. 0–30%) with No. 2 diesel to produce ternary blends of diesel–palm biodiesel–ethanol. Cold flow properties (such as, could point, pour point) of these ternary blends has improved and minute percentage of ethanol adding did not adversely affect the oxidation stability and corrosiveness of the fuel blend. Ethanol has significantly reduces the flash point, but the flammability of ternary blends is classified as Class II; similar to that of diesel. Cetane number is reduced in ternary blends by ethanol. So, palm biodiesel with minute percentage of anhydrous ethanol as additive in the ternary blend significantly improved key fuel properties significantly.

Profit and policy implications of producing biodiesel–ethanol–diesel fuel blends to specification

A nonlinear optimization model is developed in this work to analyze biodiesel–ethanol–diesel (BED) ternary blending processes. The model establishes optimal blends to improve the system profitability given production costs, market demand, and fuel prices while meeting multiple property criteria such as kinematic viscosity, density, lower heating value, cloud point, cetane number, fuel stability and sulfur content. Pertinent fuel mixing rules for predicting the fuel properties of BED blends were extrapolated from previous works and applied as constraints to the present model. Several dynamic and/or uncertainty factors were explored in further depth to quantify their impacts on the fuel composition of BED blends including petro-diesel supply reduction, diesel production cost, diesel blends market retail price, and policy changes on bio-fuel subsidies. By examining key optimization sensitivity analysis such as shadow prices and opportunity costs, the crucial limits or constraints on fuel specifications can be identified and used to proactively identify and promote the development of potential additives. The model also suggests the government policy of simultaneously implementing bio-fuel tax credits and mandates may not have a higher contribution to promoting bio-fuel production than the case only with tax credits for the firms with the goal of profit maximization. The firms enable 5–8% increase of the optimal profit from BED blends by utilizing ethanol derived from food waste feedstocks instead of edible biomass.

Particles emitted during the stops of an urban bus fuelled with ethanol–biodiesel–diesel blends

Urban buses with diesel engines produce NOx and particulate matter emissions thus affecting local city pollution. During stops, due to traffic lights, programmed stops, etc., pollutants are emitted close to people, being damaging to their health. This paper studies the effects on particle size distributions caused by the use of oxygenated fuels during stops of an urban bus. Fuels used are a blend of ethanol and diesel (denoted as ED) and a blend of ethanol, biodiesel and diesel (denoted as EBD), which are compared to a diesel fuel used as reference. Tests were carried out on a vehicle under real working conditions in the Spanish city of Seville. A Horiba 1300 on-board system (OBS) was used to measure operating conditions, and an Engine Exhaust Particle Sizer Spectrometer was used to determine particle size distributions. Results showed a reduction in the number concentration of accumulation mode when oxygenated fuels were used. However, they produced a slight increase in the nuclei mode, as well as a reduction in particle diameters from both modes when using EBD blends, being more significant when referring to accumulation mode. These findings may be considered negative for the oxygenated blends under these operating conditions.

Comparative analysis of biodiesel–ethanol–diesel and biodiesel–methanol–diesel blends in a diesel engine

In this work, standard diesel fuel, biodiesel (45%)–methanol (10%)–diesel (45%), biodiesel (40%)–methanol (20%)–diesel (40%), biodiesel (45%)–ethanol (10%)–diesel (45%) and biodiesel (40%)–ethanol (20%)–diesel (40%) blends are tested in a compression ignited engine under the same operating conditions. Performance and emission characteristics of the engine fueled with biodiesel–methanol–diesel (BMD) and biodiesel–ethanol–diesel (BED) are compared to standard diesel fuel as the baseline. Overall, biodiesel–alcohol–diesel blends show a higher brakespecific fuel consumption than diesel. As alcohol concentrations in blends increase, CO and HC emissions increase, while NO emissions are reduced. Also, methanol blends are more effective than ethanol blends for reducing CO and HC emissions, while NO reduction is achieved by ethanol blends.

Predicting the Temperature Dependent Viscosity of Biodiesel–Diesel–Bioethanol Blends

Viscosity is an important property of fuels for internal combustion engines and has normative values in quality standards for commercial fuels used in compression ignition engines. Elaborating reliable models to estimate viscosity of biodiesel–diesel–bioethanol blends is useful to blend fuels with high biofuel content that comply with the values of viscosity imposed in quality standards and to model and simulate injection and combustion processes for such fuels. For predicting viscosity of rapeseed oil biodiesel–diesel–bioethanol blends, 15 ternary mixtures were prepared, having a maximum amount of biofuel of 30% v/v. The concentration of biodiesel and bioethanol varies between 5% and 25%, in increments of 5%. Their density and viscosity were determined in nine steps in the temperature range 273.15–343.15 K. Using experimental data, a number of models to estimate the viscosity of liquid substances were evaluated, including Kay’s rule, simple and weighted semi-logarithmic model, and Refutas model. A simple additive model was proposed, named Kay’s weighted rule. The models used to describe viscosity of biodiesel–diesel–ethanol blends were critically evaluated and compared on the basis of the correlation coefficient and the percent relative deviation, demonstrating that the model proposed here provides the most accurate estimates for viscosity of biodiesel–diesel–bioethanol blends.

Combustion characteristics of a diesel engine operating on biodiesel–diesel–ethanol mixtures

Experimental investigation was carried out to analyse the combustion, performance, and emission characteristics of DI diesel engine using selective biodiesel–diesel–ethanol mixture or diestrol fuels. Eleven diestrol fuels were selected on the basis of good miscibility, calorific value, and clear appearance based on the stability test carried out at different temperatures from 40 °C to 10 °C. The engine was made to run under varying loads at a constant speed of 1500 r/min. The results revealed that the maximum heat release rate of diestrol fuel was 7.5 per cent lower than that of diesel, while the cylinder gas pressure was nearly close to that of diesel fuel at 100 per cent load condition. A shorter ignition delay of 12.8° CA was observed with diestrol fuel consisting of 30 per cent biodiesel 60 per cent diesel and 10 per cent ethanol, which was 1.9° CA higher than biodiesel and comparable to that of diesel. Maximum brake thermal efficiency of 29.91 per cent was observed for diestrol fuel. While using diestrol and biodiesel, nitric oxide (NO) and smoke emissions were lower than that of diesel at all the load conditions.

Assessment of energy performance and air pollutant emissions in a diesel engine generator fueled with water-containing ethanol–biodiesel–diesel blend of fuels

Biomass based oxygenated fuels have been identified as possible replacement of fossil fuel due to pollutant emission reduction and decrease in over-reliance on fossil fuel energy. In this study, 4 v% water-containing ethanol was mixed with (65–90%) diesel using (5–30%) biodiesel (BD) and 1 v% butanol as stabilizer and co-solvent respectively. The fuels were tested against those of biodiesel–diesel fuel blends to investigate the effect of addition of water-containing ethanol for their energy efficiencies and pollutant emissions in a diesel-fueled engine generator. Experimental results indicated that the fuel blend mix containing 4 v% of water-containing ethanol, 1 v% butanol and 5–30 v% of biodiesel yielded stable blends after 30 days standing. BD1041 blend of fuel, which composed of 10 v% biodiesel, 4 v% of water-containing ethanol and 1 v% butanol demonstrated −0.45 to 1.6% increase in brake-specific fuel consumption (BSFC, mL kW −1 h −1) as compared to conventional diesel. The better engine performance of BD1041 was as a result of complete combustion, and lower reaction temperature based on the water cooling effect, which reduced emissions to 2.8–6.0% for NO x , 12.6–23.7% particulate matter (PM), 20.4–23.8% total polycyclic aromatic hydrocarbons (PAHs), and 30.8–42.9% total BaPeq between idle mode and 3.2 kW power output of the diesel engine generator. The study indicated that blending diesel with water-containing ethanol could achieve the goal of more green sustainability.

Effect of an ethanol–biodiesel–diesel blend on a common rail injection system

The present work is focused on a comparative experimental study for determining the effect of fuel properties on the constructive characteristics of some pieces of a current common rail injection system used in light duty diesel vehicles. Two Bosch fuel injection systems, each composed by a high pressure injection pump Bosch (270 CDI), the common rail and a Bosch piezoelectric fuel injector, were selected to be tested with two fuels. The first of the systems was tested with a low sulphur commercial diesel fuel while the second was tested with an ethanol–biodiesel–diesel blend (7.7% v/v ethanol (E), 27.69% v/v biodiesel (B) and 69.61% v/v (diesel) reference diesel fuel) Both systems were tested during an accelerated durability test. In both cases, the injection systems were mounted in an injection test bench and were working during 12 h/day up to 600 h. An injection pressure of 1500 bar, a regime of 2500 min −1 and an injection time of 1 ms were selected as the most critical engine operating conditions. Test conditions were equivalent to drive a light duty vehicle during more than 120,000 km. Before and after the durability tests with each fuel tested, different pieces of the injection pump were physical characterized. Several techniques such as: a tester for the roughness surface characterization of elements, an optical microscope for the observation of the surface microstructure, an shadow comparator for geometrical characterization of elements, weighed of components by mean of an analytical balance and, finally, the nozzle dimensions were carefully determined from images of a scanning electronic microscope (SEM) of the inner shape obtained by casting silicone. Results show that the use of the ethanol–biodiesel–diesel blend tested produced a similar effect on the durability on the injection pump components studied and on the injector nozzle as that produced by diesel fuel.

Estimation of Opacity Tendency of Ethanol– and Biodiesel–Diesel Blends by Means of the Smoke Point Technique

Oxygenated fuels in diesel engines represent an alternative to conventional petroleum-derived fuel to achieve current European emissions standards (EURO 5), especially with regard to particulate matter (PM), where the reduction of the limit in mass concentration is 80% compared to that for the previous EURO 4 standard. Among these oxygenated fuels, biodiesel– and ethanol–diesel blends have great potential in reducing smoke opacity and, therefore, the particulate matter emitted. The smoke point is a technique used for determining the sooting tendency of kerosene and aviation fuels and it can be used as an indicator of smoke opacity. The smoke point technique can also be used with an extensive variety of fuels including automotive diesel fuels. This work proposes a new methodology for estimating the decrease in diesel engine exhaust opacity when different ethanol– and biodiesel–diesel blends are used instead of conventional diesel fuels. Different binary biodiesel–diesel and ethanol–diesel blends were tested in a smoke point lamp together with ternary ethanol–biodiesel–diesel blends. The results of binary blends were compared to the opacity obtained in a light duty diesel engine operating in a steady state mode confirming that the molecular weight to smoke point ratio accurately reproduces the decreasing trend in opacity, when normalized to a conventional diesel fuel, as a function of the percentage of biodiesel or ethanol in the blend. Moreover, the new proposed methodology showed how not only the oxygen content but also its functional group plays an important role in this decreasing opacity trend. In this way, tests of ternary ethanol–biodiesel–diesel blends on a smoke point lamp could predict the trend in smoke opacity when a diesel engine is fuelled with them.

Experimental investigation on diesel engine with diestrol–water micro emulsions

Experiments were conducted on a single cylinder direct injection diesel engine using diesel, biodiesel and biodiesel–diesel–ethanol (diestrol) water micro emulsion fuels to investigate the performance, emission and combustion characteristics of the engine under different load conditions at a constant speed of 1500 rpm. The results indicated that biodiesel and micro emulsion fuels had a higher brake specific fuel consumption (BSFC) than that of diesel. A slight improvement in the brake specific energy consumption (BSEC) was observed for micro emulsion fuels. The brake thermal efficiency of biodiesel and micro emulsion fuels were comparable to that of diesel. The emission characteristics like carbon monoxide (CO), carbon dioxide (CO2), unburnt hydrocarbon (UHC), nitric oxide (NO) and smoke emissions for biodiesel and micro emulsion fuels were lower than diesel fuel at all load conditions. The cylinder gas pressure of micro emulsion fuels was lower than diesel at low loads but it became almost identical to diesel at medium and full load conditions. The heat release rate for micro emulsion fuels was higher than biodiesel and diesel fuels for all loads. Biodiesel showed shorter ignition delay for the entire load range and the longer ignition delay observed for micro emulsion fuels.

Performance and emission characteristics of an CI engine fueled with diesel–biodiesel–bioethanol blends

The paper presents the experimental results obtained concerning performances and pollution of a diesel engine fueled with diesel–biodiesel–ethanol blends compared with diesel fuel in laboratory tests. The main properties of the researched fuels are presented within this paper, in comparison with classical diesel fuel (chemical composition, density, kinematic viscosity, cold filter plugging point, flash point). Engines’ performances were evaluated by determining the brake specific fuel consumption and brake thermal efficiency. For pollution evaluation the emissions of CO, CO 2, NO x , HC and smoke have been measured. An increasing of brake specific fuel consumption has been observed, especially at lower engines’ loads, with maximum 32.4%, reducing engine brake thermal efficiency with maximum 21.7%. CO emissions decrease, especially at high loads with maximum 59%, on the basis of CO 2 increased emissions. NO x emissions slightly increase, especially at partial and high loads, meanwhile HC and smoke emissions decrease in all engines’ load cycles.

Utilization of palm oil alkyl esters as an additive in ethanol–diesel and butanol–diesel blends

This research focuses on the use of biodiesel as an additive in diesohol preparation. Three types of biodiesel—methyl, ethyl, and butyl esters—were prepared from palm oil through transesterification using a conventional base catalyst. Ethanol is generally used to blend in diesohol; however, butanol is another alcohol which has higher solubility in diesel than ethanol and it can improve the fuel properties of the blends. Therefore, a comparative study of phase stability, the dependence of solubility on temperature (10, 20, and 30 °C), and an evaluation of some basic fuel properties according to the ASTM of diesel–biodiesel–ethanol and diesel–biodiesel–butanol three-component systems at different component concentrations was done. We found that the use of butanol in diesohol could solve the problem of fuel instability at low temperatures because of its higher solubility in diesel fuel. In addition, the fuel properties results indicated that blends containing butanol have properties closer to diesel than those of blends containing ethanol.

A Comparative Study of Exhaust Emissions Using Diesel-Biodiesel-Ethanol Blends in New and Used Engines

The monoalkylesters of fatty acids derived from vegetable oils or animal fats are considered an attractive alternative fuel for diesel engines. This interest is based on a number of properties of biodiesel, including the fact that it is produced from a renewable resource and its potential to reduce exhaust emissions. Although several studies have been performed on biodiesel emissions, the results have been contradictory, with some studies reporting a reduction of nitrogen oxides (NOx) emissions while others report an increase. Adjusting engine parameters like exhaust gas recirculation (EGR), retarding injection timing, and using multiple injection strategies has reduced NOx to some extent. The objective of this study was to evaluate the effect on exhaust gas emissions of blending biodiesel and ethanol into conventional diesel fuel. Ethanol could be added to diesel in limited quantities along with biodiesel since biodiesel stabilizes the ternary system by acting as an amphiphile. This article illustrates the emission characteristics of diesel-biodiesel-ethanol (DBE) fuel blends on one used engine and two new engines. DBE is a new form of oxygenated diesel fuel blend and has the potential to reduce NOx emissions and to serve as an alternative to diesel fuel. The blend ratios (diesel:biodiesel:ethanol) by volume used in this study were 70:25:5, 70:20:10, and 70:15:15. The results with DBE showed a significant reduction in NOx emissions in new engines with increased ethanol concentration, whereas with the old engine under similar conditions, an increased NOx emissions profile was observed. CO emission increased with increasing ethanol proportion in the blends in both new and old engines.

Carbonyl compounds emitted by a diesel engine fuelled with diesel and biodiesel–diesel blends: Sampling optimization and emissions profile

Biodiesel is emerging as a renewable fuel, hence becoming a promising alternative to fossil fuels. Biodiesel can form blends with diesel in any ratio, and thus could replace partially, or even totally, diesel fuel in diesel engines what would bring a number of environmental, economical and social advantages. Although a number of studies are available on regulated substances, there is a gap of studies on unregulated substances, such as carbonyl compounds, emitted during the combustion of biodiesel, biodiesel–diesel and/or ethanol–biodiesel–diesel blends. CC is a class of hazardous pollutants known to be participating in photochemical smog formation. In this work a comparison was carried out between the two most widely used CC collection methods: C18 cartridges coated with an acid solution of 2,4-dinitrophenylhydrazine (2,4-DNPH) and impinger bottles filled in 2,4-DNPH solution. Sampling optimization was performed using a 2 2 factorial design tool. Samples were collected from the exhaust emissions of a diesel engine with biodiesel and operated by a steady-state dynamometer. In the central body of factorial design, the average of the sum of CC concentrations collected using impingers was 33.2 ppmV but it was only 6.5 ppmV for C18 cartridges. In addition, the relative standard deviation (RSD) was 4% for impingers and 37% for C18 cartridges. Clearly, the impinger system is able to collect CC more efficiently, with lower error than the C18 cartridge system. Furthermore, propionaldehyde was nearly not sampled by C18 system at all. For these reasons, the impinger system was chosen in our study. The optimized sampling conditions applied throughout this study were: two serially connected impingers each containing 10 mL of 2,4-DNPH solution at a flow rate of 0.2 L min −1 during 5 min. A profile study of the C1–C4 vapor-phase carbonyl compound emissions was obtained from exhaust of pure diesel (B0), pure biodiesel (B100) and biodiesel–diesel mixtures (B2, B5, B10, B20, B50, B75). The ΣCC of the emission concentrations were 20.5 ppmV for B0 and 15.7 ppmV for B100. When considering fuel blends, the measured ΣCC were 21.4 ppmV, 22.5 ppmV, 20.4 ppmV, 14.2 ppmV, 11.4 ppmV and 14.7 ppmV, respectively, for B2, B5, B10, B20, B50 and B75. Among the target CC, both formaldehyde and acetaldehyde were the major contributors to the observed total CC levels. Except for acrolein and formaldehyde, all CC showed a clear trend of reduction in the emissions from B2 to B100 (40% reduction, on average). Both individual and total CC emission factors (pg g −1 of fuel burnt) were calculated for all tested biodiesel–diesel blends. The lowest total CC emission factor (2271 pg g −1) was found when B50 was used; the individual emission factors determined (pg g −1) were: 539.7 (formaldehyde), 1411 (acetaldehyde), 30.83 (acrolein), and 310.7 (propionaldehyde).