生物热解油精制改性研究进展

综述了近年来生物热解油的精制改性技术(如催化加氢、催化裂解、添加溶剂、乳化及催化酯化等),并对其优缺点进行了分析比较.根据生物油中化学组成的特点,指出将活泼极性基团转化为较稳定的非极性基团(如将羧基转化为酯基,将醛基转化为缩醛),是生物油精制改性十分有效的方法.     

微波辅助下固体酸催化剂对稻壳热解油的催化加氢

微波辅助下,以甲醇为溶剂的固体酸催化剂对稻壳热解油的催化加氢,采用Gc/MS分析稻壳热解油催化前后正己烷萃取物.结果表明:稻壳生物油中的化合物十分复杂,主要成分为酮、酚、醛、酸和酯等含氧化合物;在固体酸催化下,酮和酚的含量大大降低;同时,稻壳热解油催化后正己烷的萃取物中的化合物种类也有所增加;微波辅助下,固体酸催化剂对...     

生物质热解催化剂积炭问题的研究进展

生物质催化热解获得生物油等高质产品是最有前途替代传统化石能源的方法之一,但在热解过程中存在着严重的催化剂失活问题,其中积炭是导致催化剂失活的最主要因素。本文对近年来生物质催化热解领域的催化剂积炭问题进行综述,重点介绍催化剂积炭失活原因及表征方法、积炭的影响因素分析（催化剂结构、催化剂酸性与反应温度）、抑制催化剂积炭的方法 （催化剂改性、高压反应条件等）以及积炭催化剂再生方法 （氧化灼烧再生、臭氧低温再生、非热等离子体再生等）,并介绍了近年来新兴的微波催化热解技术对催化剂积炭的抑制和消除作用,然后针对该领域目前所面临的困难和发展方向进行展望,以期为生物质催化热解过程中催化剂积炭问题研究提供理论基础。     

固体酸催化剂在生物质液化及生物油改性中的应用

生物质液化是当今研究生物质能源的热点之一。本文详细综述了三大类固体酸催化剂在生物质液化中的应用现状,简单介绍了固体酸催化剂在生物油改性中的研究进展。对固体酸催化剂在生物质液化及生物油改性方面的发展前景进行了展望。     

固体酸催化剂在生物质液化及生物油改性中的应用

生物质液化是当今研究生物质能源的热点之一。本文详细综述了三大类固体酸催化剂在生物质液化中的应用现状,简单介绍了固体酸催化剂在生物油改性中的研究进展。对固体酸催化剂在生物质液化及生物油改性方面的发展前景进行了展望。     

固体酸催化制备生物柴油研究进展

生物柴油是一种具有优良燃烧性能的石化替代燃料,开发可用于通过酯交换反应制备生物柴油的固体酸催化剂已成为国内外研究热点。本文综述了固体酸在催化合成生物柴油方面的研究进展,介绍了以纳米材料、磁性材料作为载体以及掺杂稀土元素等固体酸改性方法,并对固体酸催化制备生物柴油的发展前景进行了展望。     

碱土金属氧化物基催化剂催化热解生物质研究进展

快速热解是生物质高效转化利用的重要方法之一,然而其目标产物生物油因含氧量高、组分复杂等不足而难以直接利用。通过在热解体系中引入碱土金属氧化物基催化剂,可以将热解产物中的氧元素以CO₂和H₂O等方式脱除,从而实现生物油品质的提升。总结了典型碱土金属氧化物基催化剂对生物质催化热解过程中发生的酮基化、羟醛缩合、开环和侧链断裂反应及机理,讨论了催化剂类型（CaO、MgO、基于碱土金属氧化物的分子筛和活性炭等）、生物质原料、温度、催化剂用量、停留时间、催化方式、催化剂失活等因素对生物油产率与品质的影响,并对生物质催化热解制备高品质生物油及其应用进行了展望。     

磺酸型固体酸催化剂的制备与应用研究进展

将磺酸基团引入到固体载体表面制备磺酸型固体酸以替代传统的硫酸催化剂．对磺酸型固体酸催化剂的制备和应用研究进展进行了综述．介绍了在中孔硅分子筛（如MCM-41、SBA-15）、中孔炭分子筛（如CMK-3、CMK-5）、半炭化炭材料、炭纳米管等载体上引入磺酸基团的方法和其中一些催化剂的催化性能,探讨这些制备方法和所制得催化材料的优点和存在的问题．     

ZSM-5/SBA-15复合催化剂制备及其对生物质热解制生物油

通过表面响应法,以Box-Behnken试验原理,对生物质（玉米秸秆）的非催化热解进行三因素试验,其中生物油产率为响应值,温度、升温速率、氮气流速为自变量,确定最大生物油产率的工艺参数进行催化热解。以硅酸四乙酯为硅源,通过水热合成法合成了复合催化剂ZSM-5/SBA-15,并进行玉米秸秆的微波催化热解产物分析。通过XRD、SEM、TEM、NH3-TPD进行催化剂表征,得到复合催化剂不仅具有介孔催化剂SBA-15的性质,且兼备微孔催化剂ZSM-5的性质。通过GC-MS分析,复合催化剂ZSM-5/SBA-15的加入,相比非催化热解烃类收率（6.42%）和酚类收率（39.65%）都有所增加。     

生物质催化热解制油及油品改性提质研究进展

基于国家碳中和背景，生物质作为一种重要的可再生资源，其有效利用至关重要。生物质热解制油具有规模化潜力，成为目前生物质利用的主要方式。生物质热解技术按照液化方式不同分为直接液化和间接液化，但生物质直接液化所得生物油组分不稳定，间接液化所得生物油品质取决于反应器型式、反应温度及催化剂类型等，不同制备方法的生物油品质差别较大，生物油改性提质成为其实际应用的必要条件。归纳比较了生物质热解过程中提高生物油品质的催化剂类型，着重综述了原生物油分离为轻质组分和重质组分后分别改性提质的技术路线，可转化为燃气、燃油甚至化学品，实现生物油的高值化。针对轻质油组分的改性方法有水蒸气重整制氢、催化裂解、加氢脱氧、催化酯化等，催化剂类型以分子筛及贵金属为主；而重质油组分水含量低、黏性大，相关提质研究较少，目前报道以加氢、裂化、酯化、添加溶剂、气化为主。生物油提质改性方法中，催化剂、氢源、耗能是限制其规模化、工业化应用的主要原因，降低催化剂成本及提高催化剂寿命、减少氢源使用或利用低成本氢源、简化工艺及降低反应温度是生物油提质技术发展方向。     

An FT-IR spectroscopic study of carbonyl functionalities in bio-oils

Pyrolysis bio-oil contains abundant O-containing structures. Carbonyls are particularly important not only because they are abundant and exist in many forms (e.g. as acids, esters, ketones and aldehydes) but also because they are reactive and are a key consideration of bio-oil upgrading. This study aims to investigate the distribution of carbonyl groups in a variety of bio-oil samples prepared from the pyrolysis of mallee wood, bark and leaves in a fluidised-bed reactor. Some bio-oil samples also underwent esterification reactions with methanol in the presence of solid Amberlyst acid catalyst. The bio-oil samples were diluted with isopropanol prior to the acquisition of FT-IR spectra using a CaF₂ liquid cell. The FT-IR spectra of bio-oils in the range of 1490–1850 cm⁻¹ were deconvoluted with 9 Gaussian bands. Our results reveal that the bio-oils from the pyrolysis of wood, bark and leaves of the same mallee tree species had very different concentrations and types of carbonyls, which are related to the contents of hemicellulose, cellulose, lignin and extractives in the wood, bark and leaves. Our study also reveals that the carbonyls in the light and heavy fractions of a bio-oil may react differently during the reactions of bio-oil with methanol in the presence of the Amberlyst solid acid catalyst.     

Effect of reaction conditions on the catalytic esterification of bio-oil

Studies of bio-oil upgrading via esterification of palm shell bio-oil and alcohols employing acid catalysts were carried out in this work. The effects of esterification conditions on reaction conversion and product quality were investigated. Results indicated that esterification reaction using solid acid catalyst of Amberlyst15 enabled the conversion of organic acids in the bio-oil to esters and could also reduce certain amount of active aldehydes. The utilization of H₂SO₄ liquid catalyst was found to give higher conversion at the same reaction condition. Furthermore, higher reaction conversion to esters was achievable under conditions of higher temperature, longer reaction time, higher amounts of catalyst and alcohol and the use of shorter hydrocarbon chain of alcohol. Bio-oils, after being subjected to esterification, gave moderate heating value of 23–25 MJ/kg and improved fuel properties of decreased density, viscosity, carbon residue content, ash content, pour point and acidity.     

A review on catalytic & non-catalytic bio-oil upgrading in supercritical fluids

This review article summarizes the key published research on the topic of bio-oil upgrading using catalytic and non-catalytic supercritical fluid(SCF)conditions.The precious metal catalysts Pd,Ru and Pt on various supports are frequently chosen for catalytic bio-oil upgrading in SCFs.This is reportedly due to their favourable catalytic activity during the process including hydrotreating,hydrocracking,and esterification,which leads to improvements in liquid yield,heating value,and pH of the upgraded bio-oil.Due to the costs associated with precious metal catalysts,some researchers have opted for non-precious metal catalysts such as acidic HZSM-5 which can promote esterification in supercritical ethanol.On the other hand,SCFs have been effectively used to upgrade crude bio-oil without a catalyst.Supercritical methanol,ethanol,and water are most commonly used and demonstrate catalyst like activities such as facilitating esterification reactions and reducing solid yield by alcoholysis and hydrolysis,respectively.     

生物油提质用催化剂研究进展

文章综述了生物油提质中的催化剂应用情况,包括第VIII族元素催化剂、裂解催化剂、固体酸碱催化剂。阐述了催化剂应用中的问题,最后就其发展和前景进行了展望和评述。     

生物质热解油的精制方法研究进展

本文综述了近年来国内外生物油的精制改性技术,如催化加氢、催化裂解、催化酯化、水蒸气重整和乳化,对其优缺点进行了分析,总结了生物油热解存在的主要问题,并提出了未来发展的方向。     

生物质双级催化热解制备燃料化学品的研究进展

生物质热解所得目标产物生物油因高含氧量、组分复杂等问题难以直接应用,通过使用适宜的催化剂升级热解蒸气可实现生物油的脱氧提质。本文基于前人研究,首先总结了生物质催化热解中金属氧化物和分子筛催化剂的结构特点、催化原理与催化效果。然后详细介绍了微介孔复合型、金属氧化物/ZSM-5复合型双级催化体系的构建原理、催化模式及其对于生物质催化热解产物分布规律产生的影响,并说明了双级催化体系的可行性与实用性;同时概述了影响生物质催化热解的其他因素,包括原料特性、工艺参数、操作模式等。最后针对目前双级催化热解研究与发展中存在的问题,对进行双级催化模式的比较研究、改进催化体系以降低生产成本、发掘双级催化剂的多种使用价值等方向提出了展望。     

Bifunctional Pd/Al-SBA-15 catalyzed one-step hydrogenation–esterification of furfural and acetic acid: A model reaction for catalytic upgrading of bio-oil

Al-SBA-15 supported palladium bifunctional catalysts were evaluated for one-step hydrogenation–esterification (OHE) of furfural and acetic acid as a model reaction for bio-oil upgrading. Experimental results show that it is viable to convert these unstable constituents of bio-oil to esters and alcohols through this simple and effective OHE reaction. The results of NH₃–TPD and catalytic performances show that Al-SBA-15 with medium ratio of Si/Al favors the OHE reaction between furfural and acetic acid. It is noteworthy that there is a synergistic effect between the metal sites and the acid sites over composite bifunctional catalyst of 5%Pd/Al-SBA-15 for the OHE reaction.     

Upgrading of pyrolysis bio-oil using WO<Subscript>3</Subscript>/ZrO<Subscript>2</Subscript> and Amberlyst catalysts: Evaluation of acid number and viscosity

Tungstated zirconia (WO₃/ZrO₂ with WO₃ loadings of 9.9 (WZ9.9), 15.5 (WZ15.5), and 15.7 wt% (WZ15.7)) and Amberlyst (15, 35, 36, 39 and 45) catalysts were employed to upgrade pyrolysis bio-oil of acacia sawdust through an esterification reaction using methanol at atmospheric pressure and room temperature or 80 °C. The upgrading efficiency was evaluated by measuring the total acid number (TAN) and viscosity. The viscosity and TAN of the resulting upgraded bio-oil were found to be dependent on the calcination temperature of the WO₃/ZrO₂ catalysts. At room temperature, the largest decrease in viscosity and TAN of the bio-oil and methanol mixture was obtained using WZ9.9 tungstated zirconia calcined at 900 °C. An increase in reaction temperature to 80 °C improved the flowability and TAN of the methanol-added bio-oil using WZ9.9 activated at 900 °C. The product distribution of the bio-oil upgraded using methanol revealed esterification to be the dominant reaction pathway under the reaction conditions of this study. When the ether extracted bio-oil was upgraded at 80 °C using methanol over catalysts, the Amberlyst catalysts were found more effective than tungstated zirconia catalysts in enhancing the esterification reaction and reducing TAN.     

Simultaneous catalytic esterification of carboxylic acids and acetalisation of aldehydes in a fast pyrolysis bio-oil from mallee biomass

This paper reports the simultaneous catalytic esterification and acetalisation of a bio-oil with methanol using a commercial Amberlyst-70 catalyst at temperatures between 70 and 170 °C. The bio-oil was prepared from the pyrolysis of mallee woody biomass in a fluidised-bed pyrolysis reactor under the fast heating rate conditions. Our results show that the conversion of light organic acids and aldehydes to esters and acetals rises significantly with increasing temperature, reaction time and catalysts loading. However, some acetals (e.g. dimethoxymethane) could decompose at higher operating temperatures (>110 °C) and catalyst loadings (>6 wt.%). The medium and heavy fractions of bio-oil also reacted with methanol to result in increases in their volatility (or decreases in boiling points) when their reactive O-containing functional groups were stabilised. The acid-catalysed reactions between bio-oil and methanol also decreased the coking propensity of the bio-oil reaction products.