Biodiesel is a renewable transportation fuel consisting of fatty acid methyl esters (FAME), generally produced by transesterification of vegetable oils and animal fats. In this review, the fatty acid (FA) profiles of 12 common biodiesel feedstocks were summarized. Considerable compositional variability exists across the range of feedstocks. For example, coconut, palm and tallow contain high amounts of saturated FA; while corn, rapeseed, safflower, soy, and sunflower are dominated by unsaturated FA. Much less information is available regarding the FA profiles of algal lipids that could serve as biodiesel feedstocks. However, some algal species contain considerably higher levels of poly-unsaturated FA than is typically found in vegetable oils. Differences in chemical and physical properties among biodiesel fuels can be explained largely by the fuels’ FA profiles. Two features that are especially influential are the size distribution and the degree of unsaturation within the FA structures. For the 12 biodiesel types reviewed here, it was shown that several fuel properties – including viscosity, specific gravity, cetane number, iodine value, and low temperature performance metrics – are highly correlated with the average unsaturation of the FAME profiles. Due to opposing effects of certain FAME structural features, it is not possible to define a single composition that is optimum with respect to all important fuel properties. However, to ensure satisfactory in-use performance with respect to low temperature operability and oxidative stability, biodiesel should contain relatively low concentrations of both long-chain saturated FAME and poly-unsaturated FAME.

Review of biodiesel composition, properties, and specifications

Lignin is an abundant biopolymer with a high carbon content and high aromaticity. Despite its potential as a raw material for the fuel and chemical industries, lignin remains the most poorly utilised of the lignocellulosic biopolymers. Effective valorisation of lignin requires careful fine-tuning of multiple "upstream" (i.e., lignin bioengineering, lignin isolation and "early-stage catalytic conversion of lignin") and "downstream" (i.e., lignin depolymerisation and upgrading) process stages, demanding input and understanding from a broad array of scientific disciplines. This review provides a "beginning-to-end" analysis of the recent advances reported in lignin valorisation. Particular emphasis is placed on the improved understanding of lignin's biosynthesis and structure, differences in structure and chemical bonding between native and technical lignins, emerging catalytic valorisation strategies, and the relationships between lignin structure and catalyst performance.

Paving the Way for Lignin Valorisation: Recent Advances in Bioengineering, Biorefining and Catalysis.

Recent progress in gasoline surrogate fuels

Acceptability of biodiesel by automotive sector is limited due to some of its adverse properties such as cold flow properties, oxidation stability and corrosiveness with automotive fuel system materials Adverse cold flow properties of biodiesel lead to the problem of plugging and gumming of filters and injectors There is a concern about the poor oxidation stability of biodiesel, which results in the formation of sediments and gums causing problem in the engine fuel injection system Biodiesel reacts with automotive fuel system materials adversely resulting in corrosion of metals and degradation of elastomers Beside these adverse issues, biodiesel possesses incredible inherent lubricity This article aims to review the adverse biodiesel properties like cold flow properties, oxidation stability; corrosive and acidic nature resulting in non-compatibility with automotive fuel system materials It also discusses the excellent lubrication behaviour of biodiesel and its positive impact An effort has been made to present the review of 145 research papers along with the sharing of our some in-house experimental results Additive treatment with biodiesel has been found to be suitable for improving the low temperature properties and oxidation stability Certain metallic and elastomeric components have been reported as compatible/non-compatible with biodiesel Although attempts have already been made by some researchers on the adverse properties of biodiesel but the scope is rather limited to the properties alone than correlating the same with automotive materials compatibility

Biodiesel properties and automotive system compatibility issues

Fast pyrolysis oil from pinewood chips co-processing with vacuum gas oil in an FCC unit for second generation fuel production

Selection Criteria and Screening of Potential Biomass-Derived Streams as Fuel Blendstocks for Advanced Spark-Ignition Engines

Oxygenates present in partially hydroprocessed lignocellulosic-biomass pyrolysis oils were examined for their impact on the performance properties of gasoline and diesel. These included: methyltetrahydrofuran, 2,5-dimethylfuran (DMF), 2-hexanone, 4-methylanisole, phenol, p-cresol, 2,4-xylenol, guaiacol, 4-methylguaiacol, 4-methylacetophenone, 4-propylphenol, and 4-propylguaiacol. Literature values indicate that acute toxicity for these compounds falls within the range of the components in petroleum-derived fuels. On the basis of the available data, 4-methylanisole and by extension other methyl aryl ethers appear to be the best drop-in fuel components for gasoline because they significantly increase research octane number and slightly reduce vapor pressure without significant negative fuel property effects. A significant finding is that DMF can produce high levels of gum under oxidizing conditions. If the poor stability results observed for DMF could be addressed with a stabilizer additive or removal of im...

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Properties of Oxygenates Found in Upgraded Biomass Pyrolysis Oil as Components of Spark and Compression Ignition Engine Fuels

The objective of this work was to measure knock resistance metrics for ethanol-hydrocarbon blends with a primary focus on development of methods to measure the heat of vaporization (HOV). Blends of ethanol at 10 to 50 volume percent were prepared with three gasoline blendstocks and a natural gasoline. Performance properties and composition of the blendstocks and blends were measured, including research octane number (RON), motor octane number (MON), net heating value, density, distillation curve, and vapor pressure. RON increases upon blending ethanol but with diminishing returns above about 30 vol%. Above 30% to 40% ethanol the curves flatten and converge at a RON of about 103 to 105, even for the much lower RON NG blendstock. Octane sensitivity (S = RON MON) also increases upon ethanol blending. Gasoline blendstocks with nearly identical S can show significantly different sensitivities when blended with ethanol. HOV was estimated from a detailed hydrocarbon analysis (DHA) as well as using a differential scanning calorimetry/thermogravimetric analysis (DSC/TGA) method. The DHA method allows relatively straight-forward estimation of fuel composition and temperature effects, and errors are estimated at less than 10%. The DSC/TGA produces results in good agreement with DHA, and can provide HOV as a function of fraction evaporated. A striking feature of the HOV results was the insensitivity of HOV to the hydrocarbon blendstock for temperatures up to 150°C all four hydrocarbon blendstocks had essentially the same HOV in kJ/kg and exhibited the same HOV response to blending with ethanol. HOV is much less variable than RON or S. HOV at 20% evaporated from the DSC/TGA experiment appeared to be unaffected by ethanol content while HOV at 50% evaporated increased monotonically with ethanol content. CITATION: Chupka, G., Christensen, E., Fouts, L., Alleman, T. et al., "Heat of Vaporization Measurements for Ethanol Blends Up to 50 Volume Percent in Several Hydrocarbon Blendstocks and Implications for Knock in SI Engines," SAE Int. J. Fuels Lubr. 8(2):2015, doi:10.4271/2015-01-0763. 2015-01-0763 Published 04/14/2015 Copyright © 2015 SAE International doi:10.4271/2015-01-0763 saefuel.saejournals.org NREL/CP-5400-63091. Posted with permission. Presented at the SAE 2015 World Congress & Exhibition, 21–23 April 2015, Detroit, Michigan.

Heat of Vaporization Measurements for Ethanol Blends up to 50 Volume Percent in Several Hydrocarbon Blendstocks and Implications for Knock in SI Engines

/pdf/heat-of-vaporization-measurements-for-ethanol-blends-up-to-4pgou6i9pe.pdf

Heat of Vaporization Measurements for Ethanol Blends Up to 50 Volume Percent in Several Hydrocarbon Blendstocks and Implications for Knock in SI Engines

Lisa Fouts

Papers

Selection Criteria and Screening of Potential Biomass-Derived Streams as Fuel Blendstocks for Advanced Spark-Ignition Engines

Selection Criteria and Screening of Potential Biomass-Derived Streams as Fuel Blendstocks for Advanced Spark-Ignition Engines

Properties of Oxygenates Found in Upgraded Biomass Pyrolysis Oil as Components of Spark and Compression Ignition Engine Fuels

Heat of Vaporization Measurements for Ethanol Blends up to 50 Volume Percent in Several Hydrocarbon Blendstocks and Implications for Knock in SI Engines

Heat of Vaporization Measurements for Ethanol Blends Up to 50 Volume Percent in Several Hydrocarbon Blendstocks and Implications for Knock in SI Engines