共查询到18条相似文献,搜索用时 140 毫秒
1.
2.
在碳达峰、碳中和的目标背景下,生物柴油被认为是替代化石燃料最有前途的新型能源之一。作为新型的加热方式,微波强化技术克服了传统加热方式下受热不均等缺点,在与不同催化体系偶联的过程中显著促进了酯交换反应的效率,较大幅度地提高了生物柴油的产率。本文归纳了微波技术强化酯交换反应制备生物柴油的优势,介绍了微波强化技术偶联均相催化、非均相催化、离子液体催化以及酶催化技术在生物柴油制备领域的研究进展,阐述了微波强化技术偶联各催化体系的利弊。从催化效率和环保等方面考虑,微波强化偶联非均相催化和酶催化具有更优的研究前景。最后,就该领域的研究方向提出几点展望与建议。 相似文献
3.
4.
微波辐射酸催化喜树种子油制备生物柴油工艺 总被引:5,自引:0,他引:5
研究了在微波辐射条件下硫酸催化酯交换反应转化喜树种子油制备生物柴油的工艺,同时采用HPLC分析了生物柴油产品中主要脂肪酸甲酯成分及其质量分数。通过实验考察了醇油摩尔比、反应时间、反应温度、催化剂加入质量分数对反应的影响,并得出了在微波辐射下硫酸催化喜树种子油制备生物柴油的最佳工艺条件:醇油摩尔比15∶1、微波辐射时间40 min、反应温度70℃、催化剂加入质量分数(与原料油)3%,转化率可达95%以上。结果表明,与传统硫酸催化酯交换反应相比,该方法具有催化剂加入质量分数少、反应温度低、时间短和转化率高等优点,对工业化制备生物柴油提供了科学参考价值。 相似文献
5.
6.
生物柴油是一种绿色的可再生能源,主要通过酯交换反应生产。催化剂在酯交换反应中起重要作用,固体酸催化剂因污染少、效率高、易分离而成为研究热点。本文介绍了固体酸催化制备生物柴油的反应机理,综述了国内外近几年生物柴油制备中所用固体酸催化剂的研究进展,分为固体杂多酸、无机酸盐、金属氧化物及其复合物、沸石分子筛及阳离子交换树脂等,分析了催化剂的制备流程、反应操作条件和反应结果等,得出固体酸在催化含有大量水分和游离酸的油脂酯交换反应方面具有独特的优势,且符合生物柴油绿色生产的要求,是需要进一步研究和开发的方向。 相似文献
7.
8.
生物柴油的制备技术研究进展 总被引:1,自引:0,他引:1
生物柴油作为一种可再生的绿色环保燃料,主要是由动植物油脂经过酯交换反应生成。文章概述了国内外制备生物柴油方法,重点介绍了酸、碱、酶催化及超临界工艺方法的研究进展,并对我国生物柴油产业化发展前景进行了展望。 相似文献
9.
10.
11.
The fossil fuel reserves are depleting at a more rapid rate as a result of the population growth and the ensuing energy utilization. Biodiesel is a mixture of fatty acid methyl esters produced from the transesterification of plant oils or animal fats. Moreover, the source of raw materials and manufacturing costs have become the major hurdle in the commercialization of biodiesel; thus, alternative sources such as the use of waste oils and non-edible oils together with biodiesel production techniques have long been considered. Selecting an appropriate feedstock and increasing production yield are two important approaches to decrease the costs of biodiesel production. Typically, biodiesel, which operates with electrical or conventional heating to generate high efficiency of the product, consumes a huge amount of power in a long reaction time. In contrast, chemical reactions speed up by microwave irradiation which results in producing high yields of product in a shorter chemical reaction time. In this extensive article, an effort has been made to review the use of microwave technology including multi-feedstock and recent studies on microwave-assisted heterogeneously catalyzed processes for biodiesel production. The heterogeneous catalyst performance has also been covered, including the measurement of their pysico-chemical properties. The microwave irradiation used for the synthesis of biodiesel is also included. In addition, the reaction variables impacting the transesterification process, such as heating system, microwave power, type and amount of heterogeneous catalyst, oil/methanol molar ratio, reaction time, temperature and mixing intensity, are covered. The final part of this article will cover the details of previously performed work on heterogeneous catalysts. Finally, energy balances for the traditional and microwave-based processes, conclusions, and recommendation on the topic are presented. The aim this article is to focus on recent studies on microwave-assisted heterogeneously catalyzed processes. 相似文献
12.
Microwave assisted transesterification of rapeseed oil 总被引:2,自引:0,他引:2
Rapeseed is one of the important vegetable oil sources for biodiesel production due to its high oil content (around 40%). In this study rapeseed oil was converted to biodiesel by transesterification using microwave heating. Experiments were carried out in the presence of two different alkali catalysts which are sodium hydroxide and potassium hydroxide. Effects of various reaction parameters such as catalyst ratio, reaction temperature and time were investigated. Mono-, di- and triglyceride content of biodiesel were determined by gas chromatography analysis. Yield and purity (ester content) percentages of biodiesel were specified in weight, which are 88.3–93.7% and 87.1–99.4%, respectively. The results indicated that microwave heating has effectively increased the biodiesel yield and decreased the reaction time. 相似文献
13.
探讨了SO2-4/Fe2O3固体酸催化剂的最佳制备条件,将其用于催化合成生物柴油,考察了催化剂用量、反应温度、反应时间及醇酸摩尔比对酯化反应的影响.结果表明,当浸渍硫酸浓度为0.5 mol·L-1、焙烧温度为600℃、焙烧时间为3 h时催化剂活性最强;利用自制的固体酸催化剂催化合成生物柴油,在催化剂用量为3%(以油酸质... 相似文献
14.
SO42-/Fe2O3固体酸的制备及其催化合成生物柴油的研究 总被引:2,自引:0,他引:2
探讨了SO42-/Fe2O3固体酸催化剂的最佳制备条件,将其用于催化合成生物柴油,考察了催化剂用量、反应温度、反应时间及醇酸摩尔比对酯化反应的影响。结果表明,当浸渍硫酸浓度为0.5mol·L-1、焙烧温度为600℃、焙烧时间为3h时催化剂活性最强;利用自制的固体酸催化剂催化合成生物柴油,在催化剂用量为3%(以油酸质量计)、反应温度为70℃、反应时间为2h、甲醇与油酸摩尔比为2∶1的最佳反应条件下,酯化率为63.2%。 相似文献
15.
近几年来,微波在制备生物柴油的化学工艺中被广泛应用。而微波强化化学反应的实验研究和工程应用中存在很多限制因素,物料介电特性是其中一个重要因素。针对甲醇和菜籽油加入自制催化剂的酯交换反应体系,采用矢量网络分析仪测量不同反应条件下甲醇和菜籽油酯交换反应系统的介电系数,考察反应温度、醇油摩尔比、催化剂用量等因素对介电特性的影响规律。结合酯交换反应动力学,讨论反应温度变化对介电特性的影响,从而为微波加热酯交换反应过程的多物理仿真提供物料介电信息。 相似文献
16.
17.
18.
随着生物柴油产业的快速发展,作为生物柴油副产物的甘油逐渐过剩,合理有效地利用甘油能促进生物柴油产业的良性发展。丙二醇(1,2-丙二醇和1,3-丙二醇)是重要的化工中间体,具有较高的经济价值,利用可再生的甘油催化氢解制备丙二醇替代传统的石化路线符合绿色化学的要求,因而具有广阔的应用前景。简述了利用甘油催化氢解制备丙二醇的研究背景,详细分析了甘油催化氢解的机理(包括脱水-加氢机理、脱氢-加氢机理、直接氢解机理和螯合机理),从催化剂的角度综述了甘油催化氢解制备丙二醇的研究现状和取得的研究成果,并提出了未来甘油氢解的研究方向。 相似文献