Study On Preparation Of Cold Flow Improver For Biodiesel

Biodiesel is a new environmental and renewable energy source which is a good substitution for conventional fossil diesel. It can exert a great influence on solving energy and environmental problems that the world is facing. The biodiesel industry has got fast development in recent years. However, the application is limited for its disadvantage of poor cold flow property.The purpose of this paper is to develop better cold flow improvers that can improve the cold flow property of biodiesel. The text is related to the development and synthesis of new kinds of biodiesel cold flow improvers, which contains the following parts:1. Research on the property of biodiesel that came from different raw materialsThree biodiesel samples were prepared from rapeseed oil, palm-oil and soybeanoil by alkali catalysis and transesterification.meanwhile, the important characteristics were also analysised and researched. The fatty acid composition and distribution of biodiesel were determinated by gas chromatography. The results could be regarded as an important reference for future research.2. Synthesis and characterization of cold flow improvers for biodieselA series of homopolymers were synthesised by methylacrylic acid advanced esters according to the composition and distribution of fatty acid.in biodiesel. Moreover, diffierent series of polymers were synthesised by using methylacrylate acid esters, maleic anhydride, styrene and hydroxyethyl methyacrylate as raw materials. The effects of various factors, such as initiator, solvent, reaction time and temperature on the polymerization were investigated.The best condition for reactive polymerization had been ascertained by orthogonality experiment. The results showed that the amount of initiator was 1.0% according to the weight of the monomers reactants, the amount of solvent was 40%, the reaction time was 6h, and the reaction temperature was 80℃. The structure of these products were analysed by IR and the average molecular weight of polymers was analysed by intrinsic viscosity. 3,Performance Evaluation of cold flow improvers for biodieselThe results of developed cold flow improvers showed that the cold filter plugging point (CFPP) of three kinds of biodiesel could decrease 7～8℃. the CFPP of rapeseed oil methyl esters (RME), palm oil methyl esters (PME) and soybean oil methyl esters (SME) were respectively decreased to -20℃, 0℃and -16℃.The effect of methacrylic acid mixed-ester was superior to the monoester. The effect of bipolymer was superior to terpolymer. There was good synergistic effect on synthesised improvers and T818. The effect of compounds on CFPP was better than that of the single. The CFPP of RME, PME and SME was respectively decreased 12℃, 8℃and 8℃by using them.The research also showed that the average molecular weight of polymers had close relationship with the effect of cold flow improvers. It had best effect on RME when the intrinsic viscosity of homopolymer, bipolymer and terpolymer were 68.90mL/g, 45.29mL/g and 55.90～56.28mL/g separately. The best intrinsic viscosity to PME were 48.52～49.55mL/g, 45.29～56.00mL/g and 44.95～45.41mL/g and to SME the best intrinsic viscosity was 44.60mL/g, 45.29mL/g and 44.95～45.41mL/g.The research of the rebound of CFPP showed that the source of biodiesel was the most important influence factors to the long-term storage. The CFPP of RME slightly increased when adding cold flow improvers, while The CFPP of PME was relatively stable.