3.2.2 Influence of ternary blends on the low-temperature flow properties
of BWCO
BWCO-ET-DDCL and BWCO-BT-DDCL ternary blends were mixed in specific
volume ratios. The comparative results of the PP, CFPP and CP of
BWCO-ET-DDCL and BWCO-BT-DDCL ternary blends are presented in Table 5.
The bending ratios of these ternary blends are as follows: 5:5:90,
10:10:80, 20:80:0, 20:70:10, 20:60:20, 20:50:30, 20:40:40, 20:30:50,
20:20:60 and 20:10:70.
Table 5 shows that DDCL and ET or BT exerted synergistic effects on
enhancing the low-temperature flow properties of biodiesel to a certain
degree. Thus, the ternary blending of BWCO and DDCL together with ET or
BT resulted in further improvement of the
PP, CFPP and CP of BWCO. More
importantly, both ET and BT are bio-based alcohol fuels derived from
inexpensive, green, and renewable biomass materials via fermentation
method [21-23], thus making these ternary blends environmentally and
financially feasible.
However, ternary blends of BWCO-BT-DDCL presented lower CP, CFPP and PP
than those of BWCO-ET-DDCL. Such result can be attributed to the good
intermiscibility of BWCO-BT- DDCL in contrast to that of BWCO-ET-DDCL
with identical proportions. When the ternary blends contain 20 vol.%
BWCO, the value of CFPP decreased with the increase in the amount of
DDCL. As BWCO mixed with BT and DDCL in 20:10:70, 20:20:60, 20:30:50,
20:40:40, and 20:50:30 blending ratios, the CP and CFPP were relatively
better than those of BWCO-ET, BWCO-BT and BWCO-DDCL binary blends that
contained 20 vol.% BWCO. PP also stabilized in the range of −19 °C to
−23 °C. Notably, BWCO-BT-DDCL ternary blends with the blending ratio of
20:10:70 presented the lowest CP (−17 °C) and CFPP (−19 °C) among the
blends with 20 vol.% biodiesel, PP also decreased to −23 °C. Moreover,
the amount of BWCO is still the major factor depressing the
low-temperature performance of biodiesel blends. Ternary blends of
BWCO-BT-DDCL with blending ratios of 10:10:80 and 5:5:90 presented
better cold flow properties, and the CFPP values (−30 °C and −35 °C)
decreased by 11 °C and 16 °C in contrast to those of BWCO-BT-DDCL blends
with the blending ratio of 20:10:70 (−19 °C), and were also superior to
the corresponding binary blends. In other word, the neat BWCO may be
unsuitable for using in a low-temperature climate because of the
deficiencies of its cold flow properties. Nevertheless, blending DDCL
and BT together with BWCO can obviously improve the low-temperature flow
properties of biodiesel and widen its temperature ranges for
application.
Table 5 Influence of BWCO-ET-DDCL and BWCO-BT-DDCL ternary
blends on CP, CFPP, and PP of BWCO.