Rapeseed residues utilization for energy and 2nd generation biofuels

Lignocellulosic biomass is an interesting and necessary enlargement of the biomass used for the production of renewable biofuels. It is expected that second generation biofuels are more energy efficient than the ones of first generation, as a substrate that is able to completely transformed into energy. The present study is part of a research program aiming at the integrated utilization of rapeseed suitable to Greek conditions for biodiesel production and parallel use of its solid residues for energy and second generation biofuels production. In that context, fast pyrolysis at high temperature and fixed bed air gasification of the rapeseed residues were studied. Thermogravimetric analysis and kinetic study were also carried out. The obtained results indicated that high temperature pyrolysis could produces higher yields of syngas and hydrogen production comparing to air fixed bed gasification.     

生物质气化制富氢合成气的研究进展

生物质气化制取富氢合成气因其原料的清洁可再生性、产物应用方式的多样性被认为是最具发展前景的制氢方式之一。催化剂对调控生物质气化产物组成及焦油的裂解具有重要作用。本文综述了化石能源制氢、水分解制氢和生物质制氢方法,分析了生物质气化制氢的优势和局限性,以及存在的问题;重点介绍了生物质气化制氢的影响因素(气化剂、反应温度和催化剂)和用于生物质气化的主要催化剂种类(镍基、白云石和碱及碱土金属催化剂)及其特点,分析国内外生物质气化制取富氢合成气和催化剂的研究现状,探讨了催化气化制取富氢合成气的发展前景,提出有待解决的问题和研究方向。     

清洁能源——生物质秸秆的研究进展

介绍了研究清洁能源——生物质秸秆的必要性,综述了生物质秸秆的研究进展,对秸秆发电、制燃料乙醇、生产沼气、热解气法制可燃气等作了详细的论述,提出了秸杆作为21世纪最具开发价值的绿色可再生能源,应加大其研究力度。     

TG study on pyrolysis of biomass and its three components under syngas

Pyrolysis of sawdust and its three components (cellulose, hemicellulose and lignin) were performed in a thermogravimetric analyzer (TGA92) under syngas and hydrogen. The effect of different heating rates (5, 10, 15 and 20 °C/min) on the pyrolysis of these samples were examined. The pyrolysis tests of the synthesized samples (a mixture of the three components with different ratios) were also done under syngas. The distributed activation energy model (DAEM) was used to study the pyrolysis kinetics. It is found that syngas could replace hydrogen in hydropyrolysis process of biomass. Among the three components, hemicellulose would be the easiest one to be pyrolyzed and then would be cellulose, while lignin would be the most difficult one. Heating rate could not only affect the temperature at which the highest weight loss rate reached, but also affect the maximum value of weight loss rate. Both lignin and hemicellulose used in the experiments could affect the pyrolysis characteristic of cellulose while they could not affect each other obviously in the pyrolysis process. Values of k₀ (frequency factor) change very greatly with different E (activation energy) values. The E values of sawdust range from 161.9 to 202.3 kJ/mol, which is within the range of activation energy values for cellulose, hemicellulose and lignin.     

生物质热解制生物油及其提质研究现状

生物质能源作为可再生能源的重要组成部分,其综合高效利用在能源替代与补充、保护生态环境等方面具有重要的战略意义。生物油是生物质通过热裂解技术获得的液体产物,具有能量密度较高、环境友好、可再生及可直接输送等优点,可替代传统化石燃料推广使用,解决日益严重的能源紧缺与环境污染等问题。生物质热解制油技术的开发与利用,已成为新世纪可持续能源研究领域的重要课题之一。总结了近年来生物质热解制油技术的主要研究进展,重点关注热解反应器、催化热解技术与生物油的提质利用方面的研究,介绍了碱金属、氧化物和分子筛3种生物质热解催化剂,以及乳化、催化加氢、催化裂解、催化酯化和重整制氢5种生物质提质方法,最后对生物质热解技术的现状及发展趋势进行了总结和概括。     

基于过程模拟和随机森林模型的生物质制氢过程因素分析与预测

生物质可以替代化石燃料,减少温室气体排放,是一种有前途的可再生能源。生物质通过化学链气化制备氢气,碳化活化制备活性炭,两条工艺路线耦合可以联产绿色能源氢气和具有高附加值的活性炭,但是原材料选择和工艺参数优化成为规模化生产的主要障碍。在生物质联产氢气和活性炭工艺模型的基础上,建立高性能的随机森林预测模型,并探究生物质组分、工艺参数和过程产物对联产工艺的相对重要性。结果表明:生物质组分中的灰分、碳元素、氢元素的含量以及气体重整温度和水蒸气用量是准确预测氢气浓度和产量的重要影响因素。其中,重整温度、合成气中氢气浓度、水蒸气用量三个影响因素对氢气浓度的影响高达61%,活化剂用量、水蒸气用量两个因素对氢气产量的影响高达63%。此外,基于随机森林模型对生物质制氢过程中的因素进行分析和优化,可以实现氢气浓度达到96.8%(体积)。     

Study of the potential valorisation of heavy metal contaminated biomass via phytoremediation by fast pyrolysis: Part I. Influence of temperature, biomass species and solid heat carrier on the behaviour of heavy metals

Presently, little or no information of implementing fast pyrolysis for looking into the potential valorisation of heavy metal contaminated biomass is available. Fast pyrolysis of heavy metal contaminated biomass (birch and sunflower), containing high amounts of Cd, Cu, Pb and Zn, resulting from phytoremediation, is investigated. The effect of the pyrolysis temperature (623, 673, 773 and 873 K) and the type of solid heat carrier (sand and fumed silica) on the distribution of the heavy metals in birch and sunflower pyrolysis fractions are studied. The goal of the set-up is “concentrating” heavy metals in the ash/char fraction after thermal treatment, preventing them to be released in the condensable and/or volatile fractions. The knowledge of the behaviour of heavy metals affects directly future applications and valorisation of the pyrolysis products and thus contaminated biomass. They are indispensable for making and selecting the proper thermal conditions for their maximum recovery. In view of the future valorisation of these biomasses, the amounts of the pyrolysis fractions and the calorific values of the obtained liquid pyrolysis products, as a function of the pyrolysis temperature, are determined.     

Techno-economic assessment of gasification as a process step within biomass-to-liquid (BtL) fuel and chemicals production

This study investigates the gasification process step which converts a biomass derived intermediate called slurry into synthesis gas (syngas) for subsequent synthesis of fuel and chemicals. The slurry is produced by fast pyrolysis plants and is then processed in a pressurized entrained flow gasifier. The resulting syngas has to be conditioned and cleaned before it is converted in a Fischer-Tropsch or dimethyl ether synthesis in order to complete a biomass-to-liquid (BtL) production such as the considered bioliq concept. This two-stage concept allows the economic transportation of biomass over long distances, due to the relatively high energy density of the slurry produced in the first stage. In addition, reductions in specific investments and costs for further processing in the second stage are enabled by economies of scale. This paper addresses possibilities for further process development and presents an outlook for a commercial implementation of a biomass derived slurry gasification. Within the techno-economic assessment, different process configurations for the gasification facility are analysed using an Aspen Plus process model and compared from an economic and energetic point of view. The varying process parameters are operating pressure, gasification agent, syngas composition as well as feedstock composition. The techno-economic assessment concludes that it is possible to produce syngas at costs of about 23 €-Cent/Nm³ based only on biomass feedstock. The production costs can almost be cut by half when considering co-gasification of biomass and coal. Further higher operating pressures of the gasification process are identified as a major influence on production costs reduction. The potential effects of marketing by-products such as excess heat as well as excess nitrogen are also addresses in this study.     

生物质热化学制氢的研究进展

介绍了生物质制氢的路线,详细分析了制氢研究的热点-生物质热化学方法,包括热裂解、气化及超临界水气化三种方法的研究进展,总结了相关试验方法及装置,其中介绍了催化剂的使用、实验装置的选取及操作条件的采用,指出了研究中存在的问题,最后对生物质制氢技术进行了展望。     

An overview of hydrogen production from biomass

Hydrogen production plays a very important role in the development of hydrogen economy. One of the promising hydrogen production approaches is conversion from biomass, which is abundant, clean and renewable. Alternative thermochemical (pyrolysis and gasification) and biological (biophotolysis, water–gas shift reaction and fermentation) processes can be practically applied to produce hydrogen. This paper gives an overview of these technologies for hydrogen production from biomass. The future development will also be addressed.     

生物质能源转化技术与应用(Ⅳ)——生物质热解气化技术研究和应用

生物质能源是惟一可再生、可替代化石能源转换成气态、液态和固态燃料以及其他化工原料或者产品的碳资源。随着化石能源的枯竭和人类对全球性环境问题的关注,生物质能源替代化石能源利用的研究和开发,已成为国内外众多学者研究和关注的热点。本系列讲座主要讲述以生物质资源为主要原料,通过不同途径转化为洁净的、高品位的气体、液体或固体燃料。本讲主要对生物质的热解气化方式进行了介绍,着重介绍了生物质气化集中供气、供热、发电、合成液体燃料、制氢等技术方面的研究和应用现状,并指出了目前存在的主要问题,提出了我国在生物质气化领域的重点研究方向。     

生物质热化学法制氢技术的研究进展

介绍木质生物质热化学法生产氢气的四条主要技术路线,分别是生物质气化制氢、生物质热解油制氢、生物质超临界水气化制氢、源于生物质的小分子有机物催化重整制氢方法,着重从化学反应机理、热力学模拟、催化剂种类、工艺开发、工业化进展等方面总结生物质热化学制氢技术的最新研究进展,分析了各类小分子制氢的热力学规律,并指出工业化过程存在...     

Study of the potential valorisation of heavy metal contaminated biomass via phytoremediation by fast pyrolysis: Part II: Characterisation of the liquid and gaseous fraction as a function of the temperature

Fast pyrolysis of heavy metal contaminated birch (CMB), resulting from phytoremediation, is investigated. The effect of the pyrolysis temperature (673, 773, 873 K) on the composition and evolution of the bio-oil/tar fraction and the gas fraction has been studied. The knowledge of the composition of the gaseous and liquid pyrolysis fractions, as a function of the pyrolysis temperature, affects directly future applications and valorisation of the pyrolysis products and are indispensable for making and selecting the proper thermal conditions for their optimal use. In view of the future valorisation of this heavy metal contaminated biomass, the pyrolysis temperature is imperative, because some of the heavy metals can volatilize at temperatures generally used for the co-combustion or fast pyrolysis of biomass.     

秸秆类生物质低温热解及混合气化的研究

生物质能源是一种重要的可再生能源,利用生物质和煤混合气化技术可以减少CO2的排放。研究了低温热解预处理对秸秆类生物质产物和气体浓度分布的影响,结果表明：经低温热解预处理后制得的生物焦的量和气体的浓度分布不仅与热解温度有关,而且与生物质种类的组成有很大的关系,考察了生物质焦和煤炭混合气化的热重试验,对混合气化反应性进行了有益的探索。     

生物质热解研究进展

当今社会面临着能源短缺和环境破坏日益严重等问题,生物质能源作为可再生绿色能源,大量开发利用对于工业和社会生活中具有重要的意义。生物质热解技术是将生物质转化成生物质能的有效可行方法之一。为实现生物质能源工业化、规模化生产,必须要完善热解反应技术及其核心热解反应器装置。在分析了生物质热解机理的基础上,着重介绍了热解反应器的类型以及其特点。     

Hydrogen from biomass-production by steam reforming of biomass pyrolysis oil

Thermo-conversion of biomass is one of the leading near-term options for renewable production of hydrogen and has the potential to provide a significant fraction of transportation fuel required in the future. We propose a two-step process that starts with fast pyrolysis of biomass, which generates high yields of a liquid product, bio-oil, followed by catalytic steam reforming of bio-oil to produce hydrogen. A major advantage of such a concept results from the fact that bio-oil is much easier and less expensive to transport than either biomass or hydrogen. Therefore, the processing of biomass and the production of hydrogen can be performed at separate locations, optimized with respect to feedstock supply and to hydrogen distribution infrastructure. This approach makes the process very well suited for both centralized and distributed hydrogen production. This work demonstrates reforming of bio-oil in a bench-scale fluidized bed system and provides hydrogen yields obtained using several commercial and custom-made catalysts.     

生物质能源转化技术与应用(Ⅰ)

生物质能源是唯一可再生、可替代化石能源转化成液态和气态燃料以及其它化工原料或者产品的碳资源。随着化石能源的枯竭和人类对全球性环境问题的关注,生物质能替代化石能源利用的研究和开发,已成为国内外众多学者研究和关注的热点。本文综述了我国年可获得生物质资源量达到3.14亿吨煤当量,其中秸秆和薪材分别占 54% 和 36%;现有180多亿吨林木生物质资源量、8~10亿吨可获得量和3亿吨可作为能源的利用量。生物质能转化利用的主要途径是:热化学高效转化利用的热解气化发电(供热、供气)、快速热解制备液体燃料和生物质气化合成液体燃料,以及生物化学转化技术等。同时,论述了目前已经进行的生物质研究开发技术和产业化利用进展。     

Biodegradability of biomass pyrolysis oils: Comparison to conventional petroleum fuels and alternatives fuels in current use

Concern with environmental issues such as global climate change has stimulated research into the development of more environmentally friendly technologies and energy sources. One critical area of our economy is liquid fuels. Fast pyrolysis of lignocellulosic biomass for liquids production is of particular concern, as it is one of the most interesting ways to produce renewable liquid fuel for transport and heat and power production.The aerobic biodegradability of various pyrolysis oils from different origins and of a EN 590 diesel sample was examined using the Modified Sturm (OECD 301B). The results demonstrate that all fast pyrolysis oils assessed are biodegradable with similar shaped curves with 41–50% biodegradation after 28 days, whereas the diesel sample reached only 24% biodegradation. Since pyrolysis oils achieved biodegradability over 20% these are classified as inherently biodegradable. Modelling of biodegradation processes was successfully performed with a first-order chemical reaction.The biodegradability results obtained for biomass pyrolysis oils are compared to those of conventional and alternative fuels.     

生物质热转换制氢的研究进展

氢气是一种理想的洁净能源。从能源角度和环境角度考虑,发展生物质制氢技术都具有重要的意义。生物质制氢技术主要包括热化学法和生物法,其中热化学法主要是将生物质气化或液化,再进行重整和水蒸气变换反应,获得氢气。本文综述了生物质热化学转化(包括气化、超临界水气化、热裂解等)制氢技术的研究进展,并对典型的制氢技术作了评述和展望。     

生物质热解和气化制取富氢气体的研究现状

随着世界能源和环境问题的发展,洁净的氢能源成为备受关注的新能源。目前,生物质热化学法作为制取富氢气体的有效方法而被广泛研究。本文系统地介绍了国内外通过生物质热解和气化制取富氢气体的研究现状,包括热解气化工艺、物料特性、热源类型、反应条件、气化剂及催化剂等对制取富氢气体的影响。重点介绍了不同类型催化剂在生物质热解和气化反应中的应用,以及催化剂在制取富氢气体方面的优势及其作用机理。提出生物质热解和气化制取富氢气体所面临的主要问题是寻求既高效又寿命长的新型或混合型催化剂,或者从工艺、反应器的改进入手,改善催化剂的催化环境,从而解决其失效问题。