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In this study, waste vegetable oil (WVO) subjected to different heating durations was blended with diesel fuel at different blend ratios. The blends were evaluated for carbon monoxide (CO), hydrocarbon (HC) and nitrogen oxide (NO) emissions and for the engine performance parameters. The properties of WVO-diesel blends were similar to that of diesel. The brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC) of WVO-diesel blends was comparable to that of diesel. However, blending WVO in proportions of 0.50 with diesel results in 38% reduction in the overall cost and results in reduced CO, HC and NO emission. [ABSTRACT FROM AUTHOR]

This paper studied the influence of four reaction parameters–temperature (40–80 °C), time (1–3 h), mass % of catalyst (1–3 wt%) and molar ratio of 1-propanol to sunflower oil (6:1–10:1)–on the conversion of biodiesel. To achieve a conversion of 95% or above, the transesterification was optimized to reduce the time, temperature, molar ratio of 1-propanol to sunflower oil and mass % of catalyst. The optimal conditions were a temperature of 40 °C, time of 1 h, 1-propanol to oil molar ratio at 8.71:1 and mass % of catalyst of 1.96%. The fatty acid propyl esters (FAPRE) were purified and blended with 1-propanol and mineral diesel to determine the application properties as transportation fuels. The addition of FAPRE to diesel increases the density and viscosity and improves the lubricity with no effect on CFPP even with 10 vol% of FAPRE. On the contrary, the addition of 1-propanol in the FAPRE-diesel blends had an opposite effect (decrease in density, viscosity and lubricity). Nevertheless, all the blends satisfied the requirements according to EN 590 for the tested properties. [Display omitted] [ABSTRACT FROM AUTHOR]

The increasing production and extensive use of biodiesel in the latest years call for the development of fast and cost-effective procedures for point-of-care analysis. One of the main quality parameters is the biodiesel content in diesel blends, which needs to conform to regional legislations. In this work, a microfluidic device exploiting chemical derivatization of alkyl esters and detection by smartphone-based digital-image colorimetry was developed. It was designed to ensure proper experimental conditions for chemical derivatization, including reagent release, and photometric measurements. Analytes reacted with alkaline hydroxylamine yielding the corresponding alkyl hydroxamates, measured as colored Fe(III) complexes. Analytical response was based on the measurement of the G (green) channel from RGB color system. By taking methyl linoleate as a model compound, a linear response was obtained from 0.1% to 0.6%(v/v) (Analytical signal = 69.6 +2.1 C, r = 0.999), coefficient of variation (n = 10) of 4.0% and limit of detection (99.7% confidence) of 0.04%(v/v). Procedure consumes 1.2 µL of sample, 230 µg of hydroxylamine, 480 µg of NaOH, 14 µg of Fe(III) and equivalent to 1.2 µL of 69%(v/v) HNO 3. Accurate results were achieved in relation to the MIR reference method, with agreement at the 95% confidence level. • Microfluidic device with smartphone-based digital image for point-of-care analysis. • Practical and environmental friendly determination of biodiesel in diesel blends. • Cost-effective and easily constructed microfluidic device. • Exploitation of pNIPAN polymer as a reagent compartment. • Application to biodiesel produced from different raw materials. [ABSTRACT FROM AUTHOR]

Abstract A novel procedure that uses FTIR-ATR C O signal area (1690–1800 cm−1) and a standard test method that is used for determination of fatty acid methyl ester in diesel were applied for the quantification of ethyl, propyl, butyl, isobutyl, pentyl, isopenyl, hexyl, heptyl, octyl, decyl, and dodecyl fatty acid esters in diesel. These methods were examined in the range from 0.0 to 30.0 vol% of biodiesel in diesel. The obtained correlation between concentration and FTIR absorption was highly linear (R 2 above 0.993, in most cases 0.999). Considering that diesel blends with butanol or higher alcohols with their corresponding fatty acid alkyl ester can satisfy the requirements for use in diesel engines, we tested if such blending would influence the results of those two methods. The results indicate that biodiesel can be quantified for blends with alcohol content up to 9 vol% of the total volume when signal area calibration is used. Graphical abstract Image 1 Highlights • FTIR methods for determination of biodiesel content in blends with diesel fuel. • Methods are applicable for biodiesels synthetized from different alcohols. • Influence of alcohol content on quantification of biodiesel in blends with diesel. [ABSTRACT FROM AUTHOR]

Abstract This experimental study investigates the combustion and pollutants emissions from a small scale furnace burning diesel fuel blended with raw jojoba oil. Jojoba oil to diesel proportions in the blends (on mass basis) ranging from 0 to 35% are considered for total blended fuel flow rate of about 8 kg/h. Higher fuel supply rates of about 10 kg/h were needed in order to allow for reaching higher jojoba share in the blends up to about 60%. This allows for securing sufficient amount of the higher volatility component (diesel) whose combustion would support the vaporization and subsequent ignition and combustion of the heavier jojoba oil. The presence of jojoba in the blends leads to a clear reduction in NOx and hydrocarbon (HC) emissions but it showed less impact on CO levels. Due to its high viscosity, jojoba in the blends impacts spray formation hence seems to have an indirect detrimental effect on CO emissions. Moreover, jojoba oil in the blends adversely impact thermal radiation to furnace walls due to less sooting tendency of the flame when jojoba is present. To some extent, this is also attributed to the way jojoba influences spray processes. Highlights • Raw jojoba-oil/diesel blends are used as fuel for small furnace. • 0–35% by weight of jojoba in blends is used with input fuel supply of 8.3 kg/h. • Stable flame was possible with 60% jojoba share if fuel input is 10 kg/or higher. • Jojoba reduces NOx and hydrocarbon emissions but indirectly impacts CO emissions. • Jojoba oil in the blends has adverse impact on thermal radiation to furnace walls. [ABSTRACT FROM AUTHOR]

The quality determination of biofuels requires identifying the chemical and physical parameters. The key physical parameters are rheological, thermal and electrical properties. In our study, we investigated samples of diesel blends with rapeseed methyl esters content in the range from 3 to 100%. In these, we measured basic thermophysical properties, including thermal conductivity and thermal diffusivity, using two different transient methods - the hot-wire method and the dynamic plane source. Every thermophysical parameter was measured 100 times using both methods for all samples. Dynamic viscosity was measured during the heating process under the temperature range 20-80°C. A digital rotational viscometer (Brookfield DV 2T) was used for dynamic viscosity detection. Electrical conductivity was measured using digital conductivity meter (Model 1152) in a temperature range from -5 to 30°C. The highest values of thermal parameters were reached in the diesel sample with the highest biofuel content. The dynamic viscosity of samples increased with higher concentration of bio-component rapeseed methyl esters. The electrical conductivity of blends also increased with rapeseed methyl esters content. [ABSTRACT FROM AUTHOR]

The projected growth of biodiesel world production has led to an increasing interest in finding new routes to valorize the large amount of glycerol produced linked to this biofuel obtaining process. One of these routes is glycerol transformation in value added products such as oxygen fuel additives. This review collects the latest advances in routes of glycerol valorization, considering the great majority of reactions with ketones and aldehydes, among other reactants. In order to justify the interest in these processes, this work includes a discussion of the main effects on fuel properties and engine performance. The characteristics that glycerol derivatives can provide to fuel blends, such as increasing in octane index, improving some cold flow properties or mitigating some negative aspects of other oxygenated compounds, such as environmental issues, flash point or gums formation will be exposed and discussed. [ABSTRACT FROM AUTHOR]

Polyoxymethylene dimethyl ethers (PODE n ) have aroused widespread industry interests due to the prospects for clean fuel additives or substitutes. The densities of liquid PODE n were measured with an oscillation tube densimeter and fitted with the Racket equation. The self-expanding empirical density model has been developed to predict the densities of PODE n whose pure and reliable monomer could not be readily available. The density behavior of PODE-PODE mixtures, PODE 3 - n -hexadecane and PODE 3 -tetralin blends was studied. Results showed the excess volumes of PODE-PODE are negative and approximately equal to zero, indicating PODE-PODE mixtures could be regarded as regular solution at temperatures from 273.15 to 363.15 K. While the excess molar volumes of PODE 3 -hexadecane and PODE 3 -tetralin blends are positive over the complete mole fraction range. The breaking of self-association of the PODE 3 molecules by dilution effect might make a positive contribution to excess volume besides physical interactions. The densities of practical PODE n -diesel blends were estimated and results agreed well with experimental data. [ABSTRACT FROM AUTHOR]

The present investigation evaluates the combustion, performance, and exhaust emissions of diesel fuel in blends with either 5, 10, and 15% ethanol, or with 8, 16, and 24% n-butanol, or lastly with 8, 16, and 24% diethyl ether (DEE, an isomer ether of butanol) by volume, fueling a standard, experimental, single-cylinder, four-stroke, high-speed direct injection (HSDI), Hydra diesel engine. The tests were conducted using each of the above fuel blends, with the engine operating at three different loads. Fuel consumption, exhaust gas temperature, and exhaust smoke, nitrogen oxides (NOx), carbon monoxide (CO), and total unburned hydrocarbons (HC) were measured. The differences in combustion, performance, and exhaust emissions of those biofuel blends from the baseline operation of the diesel engine (when working with neat diesel fuel) and among themselves are compared. Fuel injection diagrams, combustion chamber pressure diagrams, and heat release rate (HRR) diagrams obtained thereof, reveal some interesting features of the combustion mechanisms. These results and the differing physical and chemical properties of those biofuels among themselves and against those for the neat diesel fuel are used to aid the correct interpretation of the observed engine behavior. With increasing percentage of all biofuels in the blends, significant reduction of smoke opacity (higher for the n-butanol case) is observed, reduction of NOx (higher for the diethyl ether case), decrease of CO, and increase of HC emissions, against the corresponding neat diesel fuel case. [ABSTRACT FROM AUTHOR]

In Brazil, the National Agency of Petroleum, Natural Gas and Biofuels (ANP) is a regulatory agency responsible for monitoring the distribution and sale of fuels. After the introduction of biodiesel in Brazil, problems began to emerge as well as questions regarding the quality of diesel fuel in the country. One of the problems is related to the determination of biodiesel content in the diesel available in fuel stations. This work shows that biodiesel prepared from different feedstock during storage suffers oxidative degradation leading to different oxygenated compounds. The presence of these biodiesel oxidation products affects the accuracy of the result provided by the standard method EN 14078 in relation to the content of biodiesel in diesel. The result showed determination errors of almost 100%. Indeed, a B5 blend after accelerated oxidation was determined using EN 14078 as B10. Another problem observed using EN 14078 was that in countries like Brazil, where different oleaginous or alcohol are used to produce biodiesel, it is mandatory to calibrate the method with the same biodiesel present in diesel blends. Indeed, it was observed important changes in the position of the stretching related to the ester carboxyl group according to the raw materials used to prepare the biofuel, leading to significant errors in the biodiesel content determination. [ABSTRACT FROM AUTHOR]

Highlights: [•] Effect of the addition of antioxidants on storage stability blends of diesels with KOME. [•] Strong correlation between KOME concentration and storage stability. [•] Oxidation stability of neat KOME and its diesel blends were found to increase significantly with addition of antioxidants. [•] PY and PrG were found most effective antioxidants among all. [•] Difference in physicochemical properties shown variation in the storage stability of diesel biodiesel blends. [ABSTRACT FROM AUTHOR]

Abstract: 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. [Copyright &y& Elsevier]

The present investigation represents a concrete example of complete valorization of Eucalyptus nitens biomass, in the framework of the circular economy. Autohydrolyzed-delignified Eucalyptus nitens was employed as a cheap cellulose-rich feedstock in the direct alcoholysis to n-butyl levulinate, adopting n-butanol as green reagent/reaction medium, very dilute sulfuric acid as a homogeneous catalyst, and different heating systems. The effect of the main reaction parameters to give n-butyl levulinate was investigated to check the feasibility of this reaction and identify the coarse ranges of the main operating variables of greater relevance. High n-butyl levulinate molar yields (35–40 mol%) were achieved under microwave and traditional heating, even using a very high biomass loading (20 wt%), an eligible aspect from the perspective of the high gravity approach. The possibility of reprocessing the reaction mixture deriving from the optimized experiment by the addition of fresh biomass was evaluated, achieving the maximum n-butyl levulinate concentration of about 85 g/L after only one microwave reprocessing of the mother liquor, the highest value hitherto reported starting from real biomass. The alcoholysis reaction was further optimized by Response Surface Methodology, setting a Face-Centered Central Composite Design, which was experimentally validated at the optimal operating conditions for the n-butyl levulinate production. Finally, a preliminary study of diesel engine performances and emissions for a model mixture with analogous composition to that produced from the butanolysis reaction was performed, confirming its potential application as an additive for diesel fuel, without separation of each component. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]