长链脂肪酸在超临界水中的水热气化反应研究

发布时间：2018-03-26 21:19

本文选题：超临界水　切入点：水热气化　出处：《华东师范大学》2017年硕士论文

【摘要】：随着世界人口的快速增长以及经济的高速发展,化石能源的开发程度和消费水平迅速增加。但化石能源不可再生,且其储量十分有限。因此,转变能源结构,研究利用新一代可再生、环境友好型能源是人类可持续发展所面临的紧迫任务。生物质能源由于原料丰富、来源广泛、生产操作工艺安全等特点,近年来被普遍认为是化石燃料的主要替代能源。脂质作为生物质中重要的组成部分,因其所占比例高、分布广泛、热值高,是目前新型生物质能源的研究热点。相较于传统的生物质工业转化途径(酶降解和热裂解),通过水热气化法将其转化为燃气是一条方便快捷的路径,不需要进行干燥、萃取等大量耗能且会导致污染的额外处理,绿色环保,获得的燃气热值较高,具有良好的应用前景。本论文根据脂质在超临界水中水解后的主要成分脂肪酸,选取了一系列模型化合物,采用自制的石英釜式生物质超临界水气化反应实验装置考察其超临界水热气化过程,以期为脂质生物质的超临界水热气化研究提供实验数据参考及理论依据。本文的主要研究内如下:1.非催化条件下长链脂肪酸的超临界水热气化反应研究以正十五酸为主要研究对象,正十四酸和油酸作为验证。在不添加催化剂的情况下,各实验因素对脂肪酸SCWG的影响顺序为:反应温度反应保留时间反应物质量分数。反应温度的提升会生成更多的气体组分,元素回收率及HHV也随之上升;在一定的反应温度和压力下,反应保留时间的增加在绝大多数条件下使气体产率、元素回收率和HHV随之增加,但随着保留时间的进一步增加,气体产率、元素回收率和HHV增长幅度降低。随着反应物质量分数的增加,脂肪酸超临界水热气化(SCWG)的气体产率、元素回收率和HHV有一定降低。C元素回收率在400-450 ℃较高,在所测整体温度区间最高值为16.8%;H元素回收率在500-550℃较高,最高值为57.1%;HHV最高可达16.8kJ·kg-1,大约相当于标准煤热值的57%。液相产物除了残留未反应的脂肪酸以脂肪酸外以脱羧后的直链烃为主,同时含有部分芳香烃和高聚物。将气体产物分布数据和液相产物的表征相结合,根据脂肪酸实际分解情况,探究了脂肪酸非催化超临界水气化四种重要中间反应受各反应因素的作用及其对反应结果的影响。2.催化条件下长链脂肪酸的超临界水热气化反应研究考察了Pd/C、Pt/C、Rh/C和Ru/C四种催化剂对脂肪酸SCWG反应过程的影响,通过研究SCWG气体产物的分布,发现Ru/C对脂肪酸催化SCWG反应的催化效果最佳,C元素回收率可达95.67%,H元素回收率可达135.73%;HHV最高可达36.38 kJ·g-1,大约相当于标准煤热值的124%。实验结果表明,四种催化剂催化的SCWG气体总产率和C元素回收率均有上升;H元素回收率在Pd/C催化下基本不变,在其他三种催化剂下有较大程度的提升;HHV在Pd/C催化下略有下降,在其他三种催化剂的作用下有较大程度的提升。催化SCWG反应的脂肪酸基本完全转化,只有极少量的残留,直链饱和烃类为液相产物的主要成分;芳香烃和其他不饱和烃种类、浓度都有大幅降低。将气体产物分布数据和液相产物的表征相结合,分析了催化剂对各产物含量变化的影响及可能的催化机理。
[Abstract]:With the rapid development of the rapid growth of the world's population and economy, fossil energy development and consumption level is increasing rapidly. But the fossil energy is non renewable, and its reserves are very limited. Therefore, change the energy structure, research on the use of a new generation of renewable, environmentally friendly energy source is the urgent task for the biomass of human sustainable development. Because of the energy rich raw materials, a wide range of sources, production operation process safety, in recent years is generally considered to be the main alternative to fossil fuels. As an important lipid in biomass components, because of its high proportion, wide distribution, high calorific value, is the focus of new biomass energy compared to the traditional way. Industrial conversion of biomass (enzymatic degradation and pyrolysis), transformed into gas is a convenient path through the water steaming method, without the need for drying, extraction etc. Additional, a lot of energy and can cause pollution, high calorific value of fuel gas is obtained, which has good application prospects. This paper is based on the main components of lipid hydrolysis in supercritical water after fatty acid, a series of model compounds were selected, using the self-made silica kettle type biomass gasification in supercritical water reaction experiment apparatus to investigate the supercritical hydrothermal gasification process, provide experimental data and theoretical basis for supercritical hydrothermal gasification of biomass in order to lipid. The main research work of this paper are as follows: 1. under the condition of non catalytic supercritical hydrothermal gasification of long chain fatty acids react with acid as the main research object is fifteen, is fourteen and acid verify. Without the addition of oleic acid as catalyst under the order of the effects of experimental factors on fatty acid SCWG as the reaction temperature and the reaction time of the reactant mass fraction of retained temperature. Ascension will generate more gas component elements, recovery and HHV also increased; in certain reaction temperature and pressure, increase the retention time of the reaction gas yield in most conditions, recovery rates and HHV increased, but with the further increase of retention time, gas yield, recovery rate and elements the growth rate of HHV decreased. With the increase of the mass fraction of the reactants, fatty acids in supercritical hydrothermal gasification (SCWG) gas yield, recovery rates and HHV have lower.C recovery rates at 400-450 degrees higher in the measured temperature range the highest value is 16.8%; the recovery rate of H elements in 500-550 degrees higher and the maximum value is 57.1%; HHV reached 16.8kJ / kg-1, roughly equivalent to standard coal calorific value of 57%. liquid products in addition to straight chain fatty acid residues of unreacted fatty acid by decarboxylation after, also contain some aromatic Characterization of hydrocarbons and polymers. The gas distribution data products and liquid products combined, according to the actual situation of the decomposition of fatty acids, fatty acid non catalytic supercritical water gasification of four kinds of important intermediate reaction by various reaction factors and its influence on the reaction results of long chain fatty acid catalyzed by.2. under the condition of supercritical hydrothermal gasification reaction of Pd/C, Pt/C, Rh/C and Ru/C of four kinds of catalysts on the fatty acids of SCWG process, the distribution of SCWG gas products, found that the catalytic effect of Ru/C on the catalytic reaction of fatty acid SCWG, C element recovery was 95.67%, H element recovery rate can reach up to 135.73% HHV; 36.38 kJ - g-1, roughly equivalent to standard coal calorific value of 124%.. The experimental results show that the total yield of SCWG gas and C four catalyst element recovery rate increased; H element recovery rate under the catalysis of Pd/C basic Change, have greatly improved in the other three kinds of catalyst; HHV decreased in the presence of Pd/C has greatly improved in the other three kinds of catalyst. Fatty acid catalyzed SCWG reaction of the basic conversion, only a very small amount of residues, straight chain saturated hydrocarbons as the main composition of the liquid products; aromatic hydrocarbons and other unsaturated hydrocarbon types, concentrations were significantly reduced. The characterization of product gas and liquid product distribution data combined with the analysis of the effect of catalyst on the content changes of each product and the possible mechanism of catalysis.

【学位授予单位】：华东师范大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TK6;TQ645.6

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