Effect of Pour Point Depressants Combined with Dispersants on the Cold Flow Properties of <scp>Biodiesel‐Diesel</scp> Blends
Baoting Su, Lulu Wang, Yuan Xue, Jincan Yan, Zhenbiao Dong, Hualin Lin, Sheng Han
Abstract
Abstract Poor cold flow property is a major issue that hinders the application of biodiesel‐diesel blends. In this work, a series of methacrylate‐benzyl methacrylate‐N‐vinyl‐2‐pyrrolidone terpolymers (RMC‐MB‐NVP, R = C 12 , C 14 , C 16 , C 18 ) was synthesized and used as the pour point depressants (PPD) for waste cooking oil biodiesel blends. To further improve their depressive effects, dispersants, including Tween (40, 60, and 80), Span (40, 60, and 80), phthalic acid esters (PAE), and fatty alcohol polyoxyethylene ether (FAPE; FAPE 5, FAPE 7, and FAPE 9), were optimized and combined with the C 14 MC‐MB‐NVP terpolymers. The effects of C 14 MC‐MB‐NVP terpolymers and combined PPD (PPDC) on the cloud point (CP), cold filter‐plugging point (CFPP), and pour point (PP) of biodiesel blends were studied. Here, results showed that the presence of dispersants can efficiently enhance the solubility and dispersibility of polymeric PPD in biodiesel blends; thus, the PPDC presents better depressive effects. Among them, C 16 MC‐MB‐NVP (5:1:1) combined with FAPE 7 dispersant at 4:1 mass ratio (PPDC‐FAPE 7) showed the best synergistic effect, and the CP, CFPP, and PP of B20 treated with 2000 ppm PPDC‐FAPE 7 decreased by 4, 10, and 19 °C, respectively. Moreover, differential scanning calorimetry, polarizing optical microscope, and rheological analyses were performed to rationalize the action mechanism of these PPD and dispersants in biodiesel blends.