基于生物柴油冷滤点的燃料设计

发布时间：2018-01-30 18:31

  本文关键词： 生物柴油 冷滤点 组分调控 分子调控　出处：《安徽理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：生物柴油以其自身的可再生性和环保特性,备受世界各国的关注,生物柴油的发展在一定程度上可以缓解能源紧缺和环境污染两大问题带来的压力,对能源结构的调整也有很大帮助。但生物柴油在低温条件下,高熔点组分易结晶析出,流动性较差,影响了生物柴油的推广使用。论文主要研究内容是基于生物柴油的冷滤点(CFPP)对生物柴油进行燃料设计,从而达到改善生物柴油的低温流动性的目的,为生物柴油的推广使用积累一定的理论和实验支持。论文对实验室自制和市售的8种生物柴油的理化性质进行了测定,基本上均符合国标要求。使用气质联用仪对生物柴油组分进行测定,研究表明,生物柴油主要化学组分是由C、H和O三种元素组成的偶数碳链长碳链脂肪酸甲酯(FAME),主要包括饱和脂肪酸甲酯(SFAME,C14:0～C22:0)和不饱和脂肪酸甲酯(UFAME,C16:1～C20:1、C18:2以及C18:3)。不同原料油制备的生物柴油的化学组成不同,其CFPP、运动黏度也均存在较大差异,其中棕榈油生物柴油(PME)的CFPP最高,菜籽油生物柴油(RME)的CFPP最低;长碳链SFAME含量较高的生物柴油的运动黏度也较高,椰子油生物柴油(CCME)的SFAME含量与0号柴油(OPD)的正烷烃含量较接近,二者的运动黏度变化趋势也较接近,且运动黏度均低于其他7种生物柴油。CFPP越低,生物柴油低温流动性越好。通过分析生物柴油化学组成与CFPP的关系发现:生物柴油的长碳链SFAME含量越高,CFPP越高;短链的SFAME含量越高,CFPP越低;UFAME含量越高,不饱和度越高,CFPP越低。论文以生物柴油结晶机理为理论依据,在CFPP的基础上对生物柴油进行燃料设计。采取的设计方法包括①组分调控燃料设计。将生物柴油分别与不同原料油生物柴油、OPD、-10号柴油(-10PD)、煤油、乙醇和丁醇调合;结晶分离生物柴油的高熔点组分SFAME;以及添加低温流动性改进剂。结果表明,通过与不同燃料优化混合,以及结晶分离可降低生物柴油中SFAME的含量;加入带有极性基团添加剂使得生物柴油以大量小酯晶析出,不易生成影响低温流动性的大酯晶团。组分调控的燃料设计能有效地降低生物柴油的CFPP。②分子调控燃料设计,将制备生物柴油的甲醇分别换作乙醇和丁醇,经酯交换反应制得脂肪酸乙酯和脂肪酸丁酯,其CFPP均比同种原料油制得的FAME的CFPP低。分子调控优化生物柴油的分子结构,增长生物柴油组分酯基的碳链长度,使分子弯曲度增加,进而阻碍晶体的形成,降低生物柴油的CFPP。8种生物柴油中PME的CFPP最高为10℃,将棕榈油分别与乙醇、丁醇酯交换制得棕榈油脂肪酸乙酯(PEE)和棕摘油脂肪酸丁酯(PBE),CFPP分别为7℃和3℃,PME的CFPP得到了降低。
[Abstract]:Biodiesel has attracted worldwide attention because of its renewable and environmental characteristics. The development of biodiesel can alleviate the pressure of energy shortage and environmental pollution to a certain extent. It is also helpful to adjust the energy structure, but at low temperature, the high melting point components are easy to crystallize and the fluidity is poor. The main content of this paper is the design of biodiesel fuel based on CFPP-based cold filter point of biodiesel, so as to improve the low temperature mobility of biodiesel. The physical and chemical properties of 8 kinds of biodiesel made in laboratory and sold on the market were determined in this paper. The main chemical components of biodiesel were determined by GC-MS. The main chemical component of biodiesel was determined by C. The even carbon chain long chain fatty acid methyl ester of H and O is mainly composed of saturated fatty acid methyl ester and SFAME. C14: 0 (C22: 0) and unsaturated fatty acid methyl ester (UFAMEM C16: 1) C20: 1. C18: 2 and C18: 3. The chemical composition of biodiesel prepared from different feedstock oil is different, and its CFPPand kinematic viscosity are also different. The CFPP of palm oil biodiesel was the highest, and the CFPP of rapeseed oil biodiesel was the lowest. The movement viscosity of biodiesel with high SFAME content of long carbon chain was also higher, and the SFAME content of coconut oil biodiesel was close to the n-alkane content of No. 0 diesel oil. The change trend of sports viscosity was similar, and the sports viscosity was lower than that of other 7 biodiesel. CFPP. By analyzing the relationship between the chemical composition of biodiesel and CFPP, it was found that the higher the SFAME content of long carbon chain of biodiesel was, the higher the content of SFAME was. The higher the SFAME content of short chain is, the lower the content of SFAME is. The higher the content of UFAME, the higher the degree of unsaturation. The crystallization mechanism of biodiesel is the theoretical basis. The fuel design of biodiesel was carried out on the basis of CFPP. The design method included one component control fuel design. Biodiesel was divided into different feedstock biodiesel and different feedstock biodiesel. -10 diesel oil, kerosene, ethanol and butanol; Crystallization separation of high melting point component SFAMEof biodiesel; The results showed that the content of SFAME in biodiesel could be reduced by optimizing mixing with different fuels and crystallization separation. The addition of additive with polar group makes biodiesel precipitate with a large number of small ester crystals. It is not easy to form large ester crystals which affect the low temperature fluidity. The fuel design controlled by component can effectively reduce the CFPP.2 molecular controlled fuel design of biodiesel. Ethyl fatty acid and butyl fatty acid were prepared by transesterification of methanol from biodiesel to ethanol and butanol respectively. Its CFPP is lower than the CFPP of FAME prepared from the same feedstock oil. Molecular regulation optimizes the molecular structure of biodiesel, increases the carbon chain length of the ester group of biodiesel component, and increases the molecular curvature. Thus, the formation of crystals was blocked, and the CFPP of PME in CFPP.8 biodiesel was reduced to 10 鈩，

本文编号：1476936