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<div class="section abstract"><div class="htmlview paragraph">Mixing controlled compression ignition, i.e., diesel engines are efficient and are likely to continue to be the primary means for movement of goods for many years. Low-net-carbon biofuels have the potential to significantly reduce the carbon footprint of diesel combustion and could have advantageous properties for combustion, such as high cetane number and reduced engine-out particle and NO_x emissions. We developed a list of over 400 potential biomass-derived diesel blendstocks and populated a database with the properties and characteristics of these materials. Fuel properties were determined by measurement, model prediction, or literature review. Screening criteria were developed to determine if a blendstock met the basic requirements for handling in the diesel distribution system and use as a blend with conventional diesel. Criteria included cetane number ≥40, flashpoint ≥52°C, and boiling point or T90 ≤338°C. Blendstocks needed to be soluble in diesel fuel, have a toxicity no worse than conventional diesel, not be corrosive, and be compatible with fuel system elastomers. Additionally, cloud point or freezing point below 0°C was required. Screening based on blendstock properties produced a list of 12 that were available as fuels or reagent chemicals or could be synthesized by biofuels production researchers. This group included alkanes, alcohols, esters, and ethers. These candidates were further examined for their impact fuel properties upon blending with a conventional diesel fuel. Blend properties included cetane number, lubricity, conductivity, oxidation stability, and viscosity. Results indicate that all 12 candidates can meet the basic requirements for diesel fuel blending, although in some cases would require additive treatment to meet requirements for lubricity, conductivity, and oxidation stability.</div></div>

Biodiesel is most commonly used as a blend with petroleum diesel. At concentrations of up to 5 vol% (B5) in conventional diesel fuel, the mixture will meet ASTM D975 diesel fuel specification and can be used in any application as if it were neat petroleum diesel; for home 1. The ASTM standard for B100 to be used as a blend stock is D6751. Diesel fuel is defined in ASTM D975. ASTM D396 defines heating oils.A-A-59693A defines B20 for military use.

Lignocellulosic biomass offers a renewable carbon source which can be anaerobically digested to produce short-chain carboxylic acids. Here, we assess fuel properties of oxygenates accessible from catalytic upgrading of these acids a priori for their potential to serve as diesel bioblendstocks. Ethers derived from C2and C4carboxylic acids are identified as advantaged fuel candidates with significantly improved ignition quality (>56% cetane number increase) and reduced sooting (>86% yield sooting index reduction) when compared to commercial petrodiesel. The prescreening process informed conversion pathway selection toward a C11branched ether, 4-butoxyheptane, which showed promise for fuel performance and health- and safety-related attributes. A continuous, solvent-free production process was then developed using metal oxide acidic catalysts to provide improved thermal stability, water tolerance, and yields. Liter-scale production of 4-butoxyheptane enabled fuel property testing to confirm predicted fuel properties, while incorporation into petrodiesel at 20 vol % demonstrated 10% improvement in ignition quality and 20% reduction in intrinsic sooting tendency. Storage stability of the pure bioblendstock and 20 vol % blend was confirmed with a common fuel antioxidant, as was compatibility with elastomeric components within existing engine and fueling infrastructure. Technoeconomic analysis of the conversion process identified major cost drivers to guide further research and development. Life-cycle analysis determined the potential to reduce greenhouse gas emissions by 50 to 271% relative to petrodiesel, depending on treatment of coproducts.

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