Biodiesel Ethers: Fatty Acid-Derived Alkyl Ether Fuels as Improved Bioblendstocks for Mixing-Controlled Compression Ignition Engines

Abstract

In the last 20 years, biodiesel consumption in the United States has rapidly increased to ∼2 billion gallons per year as a renewable supplement to fossil fuel. However, further expansion of biodiesel use is currently limited in part by poor cold weather performance, which prevents year-round blending and necessitates blend walls ≤5% v/v. In order to provide a diesel fuel blendstock with improved cold weather performance (cloud point, pour point, and cold filter plug point), while at the same time maintaining other required fuel performance specifications, several biodiesel redox analogues were synthesized and tested. The best performing candidate fuels from this class showed improvement in the derived cetane number (29.3% shorter ignition delay), lower heating value (+4.7 MJ/kg), relative sooting tendency (−7.4 YSI/MJ), and cloud point (15 °C lower) when compared to a B100 biodiesel composed of an identical fatty acid profile. It was observed as a general trend that the reduced form of biodiesel, fatty alkyl ethers (FAEs), shows performance improvements in all fuel property metrics. The suite of improved properties provided by FAEs gives biodiesel producers the opportunity to diversify their portfolio of products derived from lipid and alcohol feedstocks to include longchain alkyl ethers, a biodiesel alternative with particular applicability for winter weather conditions across the US.

Application of Alkoxyalkanoates (AOAs) as Renewable Diesel Blendstocks from Chemical Coupling of High-Yield Fermentation Products

“…The large increase in DCN from structure AOA-1 → AOA-2 compared to AOA-2 → AOA-3 or AOA-3 → AOA-4 suggests that DCN values are highest when there is a difference of at least three carbons between R 1 and R 2 . This is in agreement with previously reported results, which indicate that the presence of a sufficiently lengthy hydrocarbon moiety significantly increases a fuel’s reactivity and corresponding DCN across a wide range of structural motifs. − The location of the long vs short chain ( AOA-4 → AOA-5 ) was not found to significantly impact any of the measured fuel properties, although it should be noted that the model used for YSI determination is unable to distinguish the difference from this kind of internal carbon rearrangement.…”

Locally Sustainable Biodiesel Production from Waste Cooking Oil and Grease Using a Deep Eutectic Solvent: Characterization, Thermal Properties, and Blend Performance

“…These results are consistent with our 1 H NMR (Bruker, 600 MHz) results for a mixture of FAME molecules resulting from the transesterification of waste cooking oil and grease without using DES, as well as other biodiesel 1 H NMR results. 7,14,19,20 2.3. Temperature-Dependent Kinematic Viscosity.…”

“…The 1 H NMR results [δ/ppm] are as follows: δ = 0.88, triplet, 3H, −CH 3 ; δ = 1.28, singlet, 22H, aliphatic CH 2 ; δ = 2.02, multiplet, 2H, −CH 2 –C sp2 H; δ = 2.22, triplet, 2H, OC–CH 2 –; δ = 2.80, triplet, 1H, −HC sp2 –CH 2 –C sp2 H–; δ = 3.55, singlet, 3H, CH 3 –O–; and δ = 5.31, multiplet, 2H, −CHCH–. These results are consistent with our 1 H NMR (Bruker, 600 MHz) results for a mixture of FAME molecules resulting from the transesterification of waste cooking oil and grease without using DES, as well as other biodiesel 1 H NMR results. ,,, …”

“…To increase production capacity from nonedible feedstocks, there has been much work recently on enzymatic conversion of sea-borne algae into biodiesel . Nevertheless, investigations continue in more traditional approaches using transesterification of triglycerides, from either pure oils or waste cooking oil and grease, into fatty acid methyl/ethyl esters. − The generation of glycerol-based byproducts of transesterification synthesis is problematic, as these byproducts often require additional resources and further processing to become useful materials rather than waste needing disposal, all of which increases costs and reduces sustainability aspects of biodiesel …”

In situ temperature measurements in sooting methane/air flames using synchrotron x-ray fluorescence of seeded krypton atoms

“…Hence, the results of this work can be related to the work of numerous other research groups ( 28 – 33 ). The specific methane/air flame in this study is one that we have used extensively to study soot formation from advanced biofuels ( 34 – 37 ).…”