Biodiesels Manufactured from Different Feedstock: From Fuel Properties to Fuel Atomization and Evaporation

Abstract

Different from fossil diesel, biodiesels can be manufactured from different sources of biomass or animal fat. Each biodiesel manufactured from a certain feedstock consists of different fatty acid methyl esters (FAMEs). Its FAME types and fractions are unique and are solely controlled by the mother feedstock and not the manufacturing process. One key feature that makes biodiesels different from their fossil counterparts is the oxygen contained in biodiesels. The oxygen content, FAME types, and FAME fractions vary in a wide range among biodiesels made from different feedstock and this in turn affects the fuel properties and physical processes, including atomization and evaporation. An extensive analysis has been successfully carried out in this study to examine the role of oxygen content, carbon chain length, and unsaturation degree in different biodiesels and the influence of FAMEs on key fuel properties (heating value, cetane number, viscosity, and surface tension). Furthermore, some useful information related to (i) the morphology and density of fuel fragments derived close to the nozzle exit and (ii) drop evaporation is reported. The atomization characteristics are experimentally observed using a high-speed imaging technique developed earlier, while the evaporation study is theoretically conducted using the well-known D-square model. It shows that the oxygen in the biodiesel is directly linked to the carbon chain length and the number of double bonds in the fuel molecules as well as to the key fuel properties. The viscosity of biodiesels and their constituents has a certain impact on the morphology and population of fuel fragments derived in the breakup zone, while the thermal properties have a significant effect on biodiesel evaporation. The dependence of fuel properties on atomization at the downstream locations of the spray, where the breakup process has completed, is minimal.

Approach to microalgal biodiesel production: Insight review on recent advancements and future outlook

“…These are readily available and require relatively simple processing steps for the biodiesel production 19 . The conversion of edible oils into commercial biodiesel production has generated many problems, such as breakage of the food supply chain, which raises economic competition between vegetable oil and biodiesel as well as affecting negatively biodiversity, arable land and water resources 20 …”

Kinematic viscosity prediction of jet fuels and alternative blending components via comprehensive two‐dimensional gas chromatography, partial least squares, and Yeo‐Johnson transformation

“…Viscosity is a key physical property that defines the lubricity, combustion, and emission characteristics of a fuel influencing atomization and ignition capabilities [1][2][3]. Specifically, pumpability and nozzle spray patterns are extensively dominated by fuel viscosity [4].…”

Spray Analysis of Biodiesels Derived from Various Biomass Resources in a Constant Volume Spray Chamber

“… 13 , 14 A further advantage of biodiesel is that each fuel has its characteristics depending on the feedstock. 15 …”

“…In 2019, the global biodiesel consumption was around 104 thousand tonnes per day, and European countries used approximately 39.8% of the total biodiesel . Biodiesels can be ideal sources for power generation in diesel engines owing to the following advantages: having higher flash points resulting in ease of storage, having reduced post-combustion pollutant emissions, and being renewable. − Moreover, some biodiesels can show similar spray patterns and combustion properties to those of conventional diesel fuels , and can be directly utilized in diesel engines with little or no modifications. , A further advantage of biodiesel is that each fuel has its characteristics depending on the feedstock …”

“…13,14 A further advantage of biodiesel is that each fuel has its characteristics depending on the feedstock. 15 The fuel performance of biodiesels can be investigated in conventional (or partially modified) diesel engines concerning their power production performance and emission characteristics. Numerous studies analyzed biodiesels in terms of their brake thermal efficiency and brake specific fuel consumption.…”