3.2.3 Ternary phase diagrams of ternary blends on PP, CFPP, and CP
Ternary phase diagrams were cleverly used to visualize the relationship of PP, CFPP, and CP with the blending ratios of BWCO-ET-DDCL and BWCO-BT-DDCL ternary blends. Isotherms of CFPP, PP and CP of BWCO-ET-DDCL and BWCO-BT-DDCL systems at temperatures of 0 °C, −10 °C, and −20 °C in the ternary phase diagrams were comparatively investigated and are presented in Figure 3.
Comparative results of BWCO-BT-DDCL (Figs.3B, 3D, and 3F) and BWCO-ET-DDCL (Figs. 3A, 3C, and 3E) blends show that BT together with DDCL more effectively improve the PP, CFPP, and CP of biodiesel than ET. The data depicted in Figure 3B show that, when ternary blends contain at least 75 vol.% BWCO and less than 15 vol.% BT, their CFPP values are greater than 0 °C. Similarly, blends containing 30 vol.% to 90 vol.% BWCO and less than 70 vol.% DDCL have an excellent CFPP ranging from 0 °C to −10 °C. Both of them occupy relatively narrow ranges of temperature compared with that of BWCO-ET-DDCL. Blends containing 7 vol.% to 50 vol.% BWCO and no more than 88 vol.% DDCL with an excellent CFPP can be used in low temperature areas (−10 °C to −20 °C). Otherwise, better CFPP below −20 °C can be possibly reached for ternary blends containing up to 15 vol.% BWCO, and such fuels can be used in extremely cold regions of China.
However, Figure 3 also shows that isotherms of PP, CFPP, and CP of BWCO-ET-DDCL and BWCO-BT-DDCL ternary blends have similarly varying tendencies. The areas of ternary blends with PP of −20 °C and below are wider than those of CP and CFPP, whereas the range of CP (greater than 0 °C) is the widest. Furthermore, the ranges of CP, CFPP, and PP between −10 °C and 0 °C constitute the largest areas in the ternary phase diagrams.
Figure 3. Isotherms of CFPP, PP and CP of BWCO-ET-DDCL (A, C and E) and BWCO-BT-DDCL (B, D and F) systems at temperatures of 0 °C, −10 °C, and −20 °C.