甘油水相重整制氢研究进展

甘油作为生物柴油的副产物,当前的产能严重过剩。甘油制氢,尤其是通过水相重整（APR）制取可以供燃料电池直接使用的高品质氢气,是提高甘油附加值、降低生物柴油成本的重要途径和手段。本文简述了当前生物柴油及其副产物甘油的生产,阐述了甘油的水相重整制氢反应,详细介绍了甘油水相重整制氢反应的热力学和动力学影响因素。分别从催化剂的贵金属活性组分、非贵金属活性组分和载体等三方面对甘油水相重整制氢反应进行了详细的综述,最后提出了双金属催化剂可能具有优异的催化甘油水相重整制氢性能。     

水蒸气重整生物甘油制氢的研究进展

近年来由于世界生物柴油产业的快速发展,生成过剩副产粗甘油,如何有效处置生产过程的粗甘油,已是当前生物柴油产业发展亟待解决的问题.本文对新近出现的以甘油为原料水蒸气重整制氢研究进行了综述,介绍了生物甘油组成与热解性质,总结了国内外水蒸气重整生物甘油及其CO<,2>原位吸附强化重整制氢技术的研究概况,指出吸附强化重整在低温...     

技术信息

从废弃物制氢的高效蒸气重整工艺英国Leeds大学研究人员于2009年7月13日宣布研发出从废弃物料,包括生物柴油生产的副产物甘油,生产氢气的高效蒸汽重整工艺。在500℃条件下,可使甘油蒸气重     

甘油催化重整制氢/合成气的研究进展

随着生物柴油的大规模化发展,副产物甘油的合理利用成为生物柴油产业发展的关键问题之一。对甘油蒸汽重整、水相重整和超临界重整制氢气和合成气的研究进行了综述和评价,对未来甘油重整制氢气/合成气的研究提出了不足和展望。     

典型碳氢化合物水蒸气重整制氢研究进展

  烃水蒸气重整是目前获取氢能源的重要方法之一,而甲烷、汽油和柴油作为典型烃类原料可满足于不同规模氢能源的需求。本文重点从催化剂、反应工艺和反应机理及动力学三个方面对甲烷、汽油和柴油蒸汽重整制氢进行介绍和评述。指出甲烷重整制氢镍基催化剂的改性和反应器设计以及反应条件的优化是其必然的发展趋势,汽油和柴油重整制氢催化剂未来设计必须具备高抗硫性和抗积炭性。此外,需加强甲烷、汽油和柴油蒸气重整制氢的机理和动力学研究。     

生物柴油副产物粗甘油的综合利用

生物柴油作为一种可替代化石燃料的可再生能源,得到了快速发展和规模化生产,使得其副产物甘油的产量过剩。通过简单工艺过程处理生物柴油,即可得到粗甘油,而粗甘油中除甘油外,还有其他的杂质组分,要想将其应用于食品、化妆品及医药等行业就必须对粗甘油进行精制。而当前,粗甘油精制工艺路线较为繁琐,成本较高,经济可行性比较低,故需开发粗甘油的应用空间,提高粗甘油的附加值。本文从生物柴油副产物粗甘油的综合应用入手,从生产化工产品,如1,2-丙二醇、1,3-丙二醇、DHA、PHA、丙烯醛等,用于制氢,用于制燃料添加剂,用于燃料电池,制甲醇或乙醇以及废物处理等领域概述了当前粗甘油的应用技术工艺现状。通过不断拓展粗甘油的应用前景,为生物柴油技术工艺的可持续发展提供技术支撑。     

甘油膜分离-吸附协同强化化学链重整评估

作为生物柴油的副产物,甘油理论氢气产量高,是蒸汽重整的潜在原料。基于化学链技术,结合氢气膜分离和二氧化碳吸附,对甘油化学链重整制氢过程进行热力学模拟研究,分析反应器操作压力和膜渗透侧压力的改变对氢气产量和系统热量需求的影响。结果表明,反应器压力的提高和渗透侧压力的降低可以有效的增强氢气产量,抑制甲烷的生成,系统的反应热对压力的变化并不敏感,而吸附剂甘油比的提高能够提高重整所需的热量,进而实现系统的自热。     

甘油膜分离-吸附协同强化化学链重整评估

作为生物柴油的副产物,甘油理论氢气产量高,是蒸汽重整的潜在原料。基于化学链技术,结合氢气膜分离和二氧化碳吸附,对甘油化学链重整制氢过程进行热力学模拟研究,分析反应器操作压力和膜渗透侧压力的改变对氢气产量和系统热量需求的影响。结果表明,反应器压力的提高和渗透侧压力的降低可以有效的增强氢气产量,抑制甲烷的生成,系统的反应热对压力的变化并不敏感,而吸附剂甘油比的提高能够提高重整所需的热量,进而实现系统的自热。     

柴油自热重整制氢反应及反应器

设计了带预热段的绝热管式反应器(A型)和带喷嘴及预热段的绝热管式反应器(B型),设计了相应流程并组建了柴油自热重整制氢装置,以直馏柴油为原料,研究了2种反应器内的柴油自热重整制氢反应行为。研究结果表明:2种结构的反应器均能用于柴油自热重整制氢,采用带喷嘴的绝热管式反应器可以确保雾化及气化效果良好,柴油热裂解生成甲烷的反应有助于柴油制氢过程。     

生物能源的研究现状及展望

综述了常见的生物能源如燃料酒精、生物柴油和生物制氢的应用和开发现状。对以淀粉和纤维素为原料的发酵制燃料酒精技术进行了比较,对木糖基因工程菌的构建及发酵工艺的国外新进展进行了讨论。分析了生物柴油的各种制备方法包括化学法和酶法的特点,特别是对酶法制备生物柴油进行了全面总结。对微生物制氢的菌种和不同制备工艺进行了技术经济评价。指出以纤维素为原料通过基因工程菌发酵制备燃料酒精,酶法制备生物柴油及利用有机废水进行微生物制氢可能成为新型生物能源的发展方向。     

Thermodynamic analysis of liquid phase in situ hydrogenation of glycerol for 1,3-propanediol synthesis

Based on the combination of the glycerol aqueous-phase reforming (APR) and catalytic hydrogenation of glycerol, a novel reaction system of liquid phase in situ hydrogenation of glycerol for the synthesis of 1,3-propanediol is proposed, in which hydrogen is produced from glycerol aqueous-phase reforming in the same reactor. In this new system, the glycerol is the raw material of the aqueous-phase reforming reaction; the hydrogen generated from the APR of glycerol can be quickly transformed to the in situ hydrogenation of glycerol to produce 1,3-propanediol, which can improve the selectivity of hydrogen for the APR process of glycerol. Moreover, thermodynamic calculation of the coupling processes was carried out, and standard molar enthalpies and equilibrium constants of foregoing reactions were obtained. The above calculation results indicate that the combination process is feasible for 1,3-propanediol synthesis.     

流化床二氧化碳吸附强化甘油重整的数值模拟

生物甘油催化重整技术为制氢工业的发展提供了广阔的前景,而二氧化碳吸附强化重整因能降低能耗和促进氢气产量被广泛关注。基于欧拉-欧拉双流体模型,结合化学反应动力学,对流化床反应器中二氧化碳吸附强化甘油重整过程开展了数值模拟,评估了催化剂和吸附剂颗粒在反应器中的流动行为,分析了操作压力对气体产物分布的影响。结果表明,催化剂和吸附剂在床中形成了典型的内循环流动结构,压力的增加会促进吸附反应,但在一定程度上减少了氢气的纯度。     

Glycerol Reforming for Hydrogen Production: A Review

Glycerol, which is obtained as a by‐product in biodiesel production, represents a candidate source of hydrogen that is renewable. Its conversion into hydrogen can be achieved by a reforming process. In this article, the glycerol reforming reaction is reviewed. Different reforming processes for hydrogen production, viz. steam, aqueous, and autothermal reforming, are described in brief. The thermodynamic analyses, which enable comparison with experimental studies, are considered. A discussion on experimental investigations over several catalysts is presented, too. Many reaction pathways are possible and some of them are dependent on the properties of the catalyst used. Generally, Ni, Pt, and Ru catalysts facilitate hydrogen production. The same catalysts are also effective for the reforming reaction of ethanol – another renewable resource for hydrogen. While ethanol steam reforming has been comprehensively reviewed by now, an overview on glycerol reforming is still missing. In this paper, an evaluation of the published studies is given to close this gap.     

Kinetics and Reactor Modeling of Hydrogen Production from Glycerol via Steam Reforming Process over Ni/CeO2 Catalysts

As a result of skyrocketing prices, environmental concerns and depletion associated with fossil fuels, renewable fuels are becoming attractive alternatives. In this respect, the demand for biodiesel has increased tremendously in recent years. Increased production of biodiesel has resulted in a glut of glycerol that has reduced the demand for this once valuable commodity. Consequently, finding alternative uses for glycerol is a timely proposition. One alternative is producing renewable hydrogen from this cheap commodity. Only a handful of studies have been conducted on producing hydrogen from glycerol. Previous studies have mainly focused on finding effective catalysts for glycerol steam reforming. This paper extends previous knowledge by presenting kinetic parameters in relation to glycerol steam reforming over Ni/CeO₂ and a reactor modeling. The study found that the activation energy and the reaction order for the glycerol steam reforming reaction over Ni/CeO₂ catalyst were 103.4 kJ/mol and 0.233, respectively.     

Hydrogen Production by Sorption‐Enhanced Steam Glycerol Reforming: Sorption Kinetics and Reactor Simulation

Sorption‐enhanced glycerol reforming, an integrated process involving glycerol catalytic steam reforming and in situ CO₂ removal, offers a promising alternative for single‐stage hydrogen production with high purity, reducing the abundant glycerol by‐product streams. This work investigates this process in a fixed‐bed reactor, via a two‐scale, nonisothermal, unsteady‐state model, highlighting the effect of key operating parameters on the process performance. CO₂ adsorption kinetics was investigated experimentally and described by a mathematical reaction‐rate model. The integrated process presents an opportunity to improve the economics of green hydrogen production via an enhanced thermal efficiency process, the exothermic CO₂ adsorption providing the heat to endothermic steam glycerol reforming, while reducing the capital cost by removing the processing steps required for subsequently CO₂ separation. The operational time of producing high‐purity hydrogen can be enhanced by increasing the adsorbent/catalyst volume ratio, by adding steam to the reaction system and by increasing the inlet reactor temperature. © 2012 American Institute of Chemical Engineers AIChE J, 59: 2105–2118, 2013     

Hydrogen Production from Glycerol Over Nickel Catalysts Supported on Al<Subscript>2</Subscript>O<Subscript>3</Subscript> Modified by Mg,Zr, Ce or La

Hydrogen production from glycerol reforming in liquid (aqueous phase reforming, APR) and vapor (steam reforming SR) phase over alumina-supported nickel catalysts modified with Ce, Mg, Zr and La was studied. Characterization of catalysts by temperature programmed reduction and XPS analyses revealed important structural effects: (i) the intercalation of Mg between nickel and alumina that inhibited the alumina incorporation to nickel phases, (ii) the close contact between Ni and Zr phases and, (iii) the close surface interaction of La and Ce ions with NiO phases. The catalytic activity of the samples studied in this work clearly indicated the different catalyst functionalities necessary to carry out aqueous-phase and vapor-phase steam reforming of glycerol. For aqueous phase reforming of glycerol, the addition of Ce, La and Zr to Ni/Al₂O₃ improves the initial glycerol conversions obtained over the Ni/Al₂O₃ supported catalyst. It is suggested that the differences in catalytic activities are related with geometric effects caused by the decoration of Ni phases by Ce and La or by the close interaction between Ni and Zr. In spite that nickel catalysts showed high APR activities at initial times on stream, all samples showed, independently of support, important deactivation rates that deactivate the catalysts after few hours under operation. Catalysts characterization after APR showed the oxidation of the active metallic Ni during reaction as the main cause of the observed deactivation. In the case of the glycerol steam reforming in vapor phase, the use of Ce, La, Mg and Zr as promoters of Ni based catalysts increases the hydrogen selectivity. Differences in activity were explained in terms of enhancement in: surface nickel concentration (Mg), capacity to activate steam (Zr) and stability of nickel phases under reaction conditions (Ce and La).     

Production of Biomass-Derived Chemicals and Energy: Chemocatalytic Conversions of Glycerol

The growing production of biodiesel as a renewable source-based fuel leads to an increased amount of glycerol. Thus, it is a favorable starting material to obtain highly functionalized products. From a variety of catalytic reactions three examples, namely glycerol oxidation, glycerol hydrogenolysis and aqueous-phase reforming, were chosen for detailed studies in our group. The experimental focus for the oxidation of glycerol was set on preparation and detailed examination of supported Pt–Bi catalysts in batch reactions as well as in continuous experiments using a trickle bed reactor. For aqueous-phase reforming of glycerol to hydrogen the addition of tin to supported platinum catalysts was investigated. Ruthenium and copper based catalysts could be successfully applied in the hydrogenolysis of glycerol to 1,2-propanediol.