3.1 Compositions and fuel properties of BWCO, DDCL, ET and BT
The total ion chromatogram and the
fatty
acid methyl ester (FAME) compositions of the neat BWCO are shown in
Figure 1 and Table 1. The BWCO is composed of FAMEs with different
carbon chains and saturated compositions. As shown in Figure 1 and Table
1, although the unsaturated FAMEs (73.41 wt.%) in the prepared BWCO are
more than saturated FAMEs, the relatively higher content of saturated
esters (25.77 wt.%) always resulted in the weaker low-temperature
fluidity of BWCO. Table 3 shows that the PP, CFPP, and CP of BWCO are 4
°C, 5 °C, and 6 °C, respectively, and other fuel properties, such as
acid value, oxidation stability, flash point, density, and kinematic
viscosity are within the ASTM D6751 and EN 14214 limits.
The compositions and fuel properties of DDCL are differ from that of
BWCO. Figure 2 and Table 2 show the total ion chromatogram and
compositions of DDCL. DDCL is a liquid fuel direct obtained from solid
coal liquefaction reaction and mainly consists of hydrocarbons,
cycloalkanes, alkanes, and alkenes [15, 18]. Thus, DDCL exerted
better low-temperature flow properties than biodiesel due to their lower
melting points. The CP, CFPP and PP of DDCL reached −41 °C, −49 °C and
−62 °C, respectively [15]. These results are well consistent with
the results of previous reports [19, 20]. Similarly, the melting
point of ethanol (ET) and 1-butanol (BT) had lower values of −114 °C and
−89 °C, respectively. Therefore, blending ET, BT and DDCL with BWCO can
potentially enhance the low-temperature flow properties of biodiesel.