Effect of Pour Point Depressants Combined with Dispersants on the Cold Flow Properties of Biodiesel‐Diesel Blends

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 = C12, C14, C16, C18) 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 C14MC‐MB‐NVP terpolymers. The effects of C14MC‐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, C16MC‐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.

Methcyclohexyl methacrylate-methacrylate copolymers：An effective cold flow improver for the biodiesel blends

“…Waste cooking oil was obtained from Shanghai Zhong-qi Environment Technology Co., Ltd. (Shanghai, China). Biodiesel was prepared in the laboratory according to the previous reports (Su et al, 2021;Wang et al, 2015;Zhao et al, 2016).…”

“…Pour point depressants (PPDs), also known as cold flow improvers (CFI), is a kind of oil additives which can improve the cold flow properties of diesel significantly just at a small dosage (Su et al, 2021;Gu et al, 2018;Wang et al, 2014;Du et al, 2013). Adding PPDs have proved to be a much simpler and more efficient way, to enhance the cold flow properties of biodiesel or biodiesel blends.…”

Improving the cold flow properties of biodiesel from waste cooking oil by ternary blending with bio‐based alcohols and diesel from direct coal liquefaction

“…Smith et al, 2010). Nevertheless, many methods can be used to mitigate this problem, such as modifying structures (Malins et al, 2014;Silva et al, 2015), winterization (Do gan & Temur, 2013;Nainwal et al, 2015), adding pour point depressants (Su et al, 2020;, and blending with diesel (Candeia et al, 2009;Xue, Zhao, Ma, et al, 2016).…”

“…One of the major technical obstacles that hinders the developments and application of biodiesel fuels is the poor low‐temperature flow properties, which may cause blockage of the oil pipelines and filter due to the crystallization and gelatinization of the saturated fatty acid methyl esters (FAME) with high melting points in biodiesel fuels (Jeong et al, 2008; Smith et al, 2010). Nevertheless, many methods can be used to mitigate this problem, such as modifying structures (Malins et al, 2014; Silva et al, 2015), winterization (Doğan & Temur, 2013; Nainwal et al, 2015), adding pour point depressants (Su et al, 2020; Xue, Zhao, Xu, et al, 2016), and blending with diesel (Candeia et al, 2009; Xue, Zhao, Ma, et al, 2016).…”

Effect of poly(ethylene-vinyl acetate) pour point depressant on the cold flow properties and crystallization behavior of soybean biodiesel blends fuel

“…B60 (60 vol.% biodiesel+40 vol.% diesel) with 1% 10-320 PPD produced the most signifificant reduction in biodiesel blends, and the CFPP reduced by 7°C. Also, the dispersants were combined with the methacrylate-benzyl methacrylate-Nvinyl-2pyrrolidone terpolymers (RMC-MB-NVP, R = C12, C14, C16, C18) to improve the cold flow properties waste cooking oil biodiesel blends [19] Among them, C16MC-MB-NVP (5:1:1) combined with the dispersant of fatty alcohol polyoxyethylene ether (FAPE 7) at 4:1 mass ratio showed the best synergistic effect, and the CFPP of B20 decreased by 10°C at 2000 ppm. However, given that biodiesel compositions vary with the source and the unsatisfying and low depressive effect on 11 the CFPP, studies on the mechanism of PPD-supplemented biodiesel at low temperatures are required because this mechanism remains unclear.…”