玉米燃料乙醇生命周期系统分析

在一定程度上玉米燃料乙醇是作为化石燃料的代替品,其生命周期系统是测试其可持续的主要标准。在基于生命周期的分析原理当中,相关研究部门建立起了玉米燃料乙醇中净能量分析方式,以我国玉米燃料乙醇的实际生产条件为例,计算出整个玉米燃料乙醇的生命周期能量效率并对其进行详细的分析。当前,我国玉米燃料乙醇生命周期系统需要通过化石能以及太阳能驱动,并不可避免地伴有二氧化碳等其他污染物的排放。所以分析玉米燃料乙醇的能量平衡,可再生性以及温室气体的排放等问题对于当前生物能源生产的系统建立及其可持续运行是有着极为重要的现实意义。     

生物燃料乙醇生产废水水质变化对污水处理的影响

国内生物燃料乙醇生产,大多数以玉米、陈化水稻、木薯等淀粉质原料为主.生物燃料乙醇在生产过程中产生的高浓度有机废水会对周边生态环境造成严重不利影响,需要采用适宜的污水处理方式,切实提升乙醇生产期间的生态及环保效益.本文就针对此,分析生物燃料乙醇废水来源,提出生物燃料乙醇废水水质变化对污水处理的影响及处理措施,最后就污水处...     

燃料乙醇温室气体排放与能量投入/产出的探讨

介绍了基于全生命周期评价和生物燃料系统分析模型的燃料乙醇温室气体排放及能量投入/产出研究结果,总结相关研究工作进展。从降低温室气体排放和能量投入/产出比的角度,对燃料乙醇原料的选择、生产工艺优化的指导原则、能源产品多元化以及工厂布局与物流等问题提出相应建议。     

中粮(安徽)非粮乙醇技术改造能量投入/产出分析

中粮(安徽)15万吨/年粮食燃料乙醇的非粮原料技术改造取得了预期效果。本文在概述非粮原料改造基础上,采用能量投入/产出分析方法,对以木薯和玉米为原料的燃料乙醇生产过程的能量效率进行了分析,对原料变化产生的影响进行评价,最后展望今后采用非粮路线发展生物质液体燃料的前景。结果表明,生产环节改造对能量效率变化具有重要影响。玉米乙醇的净能量值为1.77MJ/L,木薯乙醇为7.82MJ/L,以木薯为原料的燃料乙醇具有较高的能量效率。但综合考虑能量效率、碳排放及土地利用等因素,继续拓展生物质原料应以农林废弃物为主,木薯原料的使用规模不宜轻易扩大。     

玉米发酵生产天然气与燃料乙醇的对比

天然气和燃料乙醇作为一种清洁能源,具有相对清洁、绿色的特性,一直受到广泛的关注。本文基于玉米发酵生产天然气和燃料乙醇的核算,通过从产品质量、环保要求、能量消耗以及产生热值等方面进行对比分析。结果表明以玉米为原料发酵生产天然气比生产燃料乙醇获得的能量更多,消耗的能量更少,经济价值更大。本研究为清洁能源的技术发展提供了理论依据。     

欧美生物燃料发展陷困境 国内生物燃料乙醇现尴尬

正据美国《商业周刊》杂志网站报道,由于生产生物燃料不仅成本高昂,还带来了环境破坏、粮食价格抬高等问题,欧盟和美国相继出台政策,下调未来生物燃料生产目标。据报道,2007年,美国立法规定2008年汽油混合燃料生产量要达到90亿加仑,到2022年这一数字要升至360亿加仑。2013年美国国家环保局要求燃料生产公司添加140亿加仑玉米乙醇和27.5亿加仑由木屑和玉米苞叶生产的高级生物燃料。2009年欧盟也提出目标:到2020年乙醇需占到总运输燃料的10%。尽管生产乙醇成本高昂,但问题关键不在于此,在于美欧这些政策对解决贫困、环境问题无济于事。全球乙醇消费量在21世纪以来的这十多年呈五倍增长,全球粮食价格不断上涨,给贫困人口带来了严重影响。除此之外,生产生物燃料对环境保护也得不偿     

中国科学家在生物燃料转化方面取突破

<正>10日,中国科学院成都生物研究所发布了一项在生物燃料领域的研究成果,该所研究人员通过克服原料难以降解的特征,从而提高生物燃料乙醇的产量,并节约生产成本。随着石油枯竭和环境污染问题日益严重,生物燃料乙醇的发展受到了世界各国的普遍的关注和重视。作为第一代燃料乙醇,玉米(美国)和甘蔗(巴西)等粮食作物为主要原料,在过去的几十年里得到了迅速的发展。而在一些土地资源紧缺和粮食危机的一些发     

纤维素类生物质炼制燃料乙醇的多产品共生模式研究

利用纤维素类生物质炼制燃料乙醇是世界可再生能源发展的主要趋势.以纤维素类生物质玉米秸秆为研究对象,在系统工程、生态工业指导思想下,对纤维素类生物质炼制燃料乙醇副产物资源化过程开展研究.通过对生物质玉米秸秆炼制燃料乙醇过程主要副产物资源化的利用方案比较论证,综合技术、经济、环境、市场等因素,提出了纤维素类生物质炼制燃料乙醇生产过程的副产物CO2、预处理废液、木质素、酒精废糟液资源化利用的多产品共生模式.并对该共生模式的能量和水进行了集成分析,提出了该共生模式的生态环境风险防范措施.     

我国液体生物燃料的经济性研究

生物燃料来源于可再生资源,是一种很有发展潜力的清洁能源。目前,我国液体生物燃料主要有燃料乙醇、生物柴油、生物航煤等。由于原料成本在生物燃料成本构成中所占比重较大,降低原料收集采购成本、鼓励技术创新、降低原料消耗、出台相关优惠政策、提高液体生物燃料的经济性可促进我国液体生物燃料的可持续发展。本文分析了我国液体生物燃料的原料来源及价格、液体生物燃料的成本及经济性,提出发展液体生物燃料应结合我国原料资源特点,燃料乙醇发展需因地制宜,促进粮食燃料乙醇向非粮燃料乙醇的转型;出台对纤维素燃料乙醇的财税补贴政策;加大生物柴油和生物航煤产业链的财税扶持力度等相关建议。     

原料供应困扰我国生物燃料产业发展

日前中国生物燃料考察组前往美国和巴西，进行了生物燃料技术和市场的应用考察。 通过走访相关部门和企业了解到，目前美国的燃料乙醇生产是以玉米为主要原料，生物柴油则是以转基因大豆为主要原料，其原料供给能够满足生物燃料生产需求；巴西燃料乙醇生产是以甘蔗为原料，生物柴油的原料品种更多，其原料供给适应巴西的自然条件。     

Reducing the energy demand of corn‐based fuel ethanol through salt extractive distillation enabled by electrodialysis

The thermal energy demand for producing fuel ethanol from the fermentation broth of a contemporary corn‐to‐fuel ethanol plant in the U.S. is largely satisfied by combustion of fossil fuels, which impacts the possible economical and environmental advantages of bioethanol over fossil fuels. To reduce the thermal energy demand for producing fuel ethanol, a process integrating salt extractive distillation—enabled by a new scheme of electrodialysis and spray drying for salt recovery—in the water‐ethanol separation train of a contemporary corn‐to‐fuel ethanol plant is investigated. Process simulation using Aspen Plus® 2006.5, with the electrolyte nonrandom two liquid Redlich‐Kwong property method to model the vapor liquid equilibrium of the water‐ethanol‐salt system, was carried out. The integrated salt extractive distillation process may provide a thermal energy savings of about 30%, when compared with the contemporary process for separating fuel ethanol from the beer column distillate. © 2011 American Institute of Chemical Engineers AIChE J, 2012     

Combustion heat release analysis of ethanol or n-butanol diesel fuel blends in heavy-duty DI diesel engine

An experimental study is conducted to evaluate the effects of using blends of diesel fuel with either ethanol in proportions of 5% and 10% or n-butanol in 8% and 16% (by vol.), on the combustion behavior of a fully-instrumented, six-cylinder, turbocharged and after-cooled, heavy duty, direct injection (DI), ‘Mercedes-Benz’ engine installed at the authors’ laboratory. Combustion chamber and fuel injection pressure diagrams are obtained at two speeds and three loads using a developed, high-speed, data acquisition and processing system. A heat release analysis of the experimentally obtained cylinder pressure diagrams is developed and used. Plots of histories in the combustion chamber of the heat release rate and temperatures reveal some interesting features, which shed light into the combustion mechanism when using these promising bio-fuels that can be derived from biomass (bio-ethanol and bio-butanol). The key results are that with the use of these bio-fuels blends, fuel injection pressure diagrams are very slightly displaced (delayed), ignition delay is increased, maximum cylinder pressures are slightly reduced and cylinder temperatures are reduced during the first part of combustion. These results, combined with the differing physical and chemical properties of the ethanol and n-butanol against those for the diesel fuel, which constitutes the baseline fuel, aid the correct interpretation of the observed engine behavior performance- and emissions-wise.     

燃料乙醇生产用生物原料的土地使用、能耗、环境影响和水耗分析

在引入生物质分配比率的基础上,从土地使用率、能耗、环境和耗水量4个方面分析了玉米秸秆、木薯和甜高粱3种生物质原料生产燃料乙醇的过程,得到了3种生物质发展潜力数据. 结果表明,玉米秸秆作为原料,按产出乙醇能计,土地使用率最高可达563.40 GJ/ha,投入能量最低,仅为22.68 MJ/GJ,环境影响最小,耗水量最少,只有8 m3/GJ,是最有开发前景的原料. 甜高粱总体上优于木薯,但耗水量太大,不利于长远发展.     

纤维素燃料乙醇技术经济分析

考察了以玉米秸秆为原料生产燃料乙醇的工艺流程,对年产5万t燃料乙醇的生产工艺进行了技术经济和敏感性分析. 蒸馏能耗分析表明,当发酵醪中乙醇浓度高于4%(w)时蒸馏的能耗比较低. 年产5万t燃料乙醇的直接固定成本约1.37亿元,乙醇的最低成本为8425 ￥/t. 该工艺能副产3.75万t CO2和215 t杂醇油,可带来额外收益2386万元. 经济敏感性分析表明,纤维素酶价格对生产成本的影响较显著,副产物CO2的回收利用可明显增加收益.     

玉米燃料乙醇低能耗工业生产新工艺

本团队研发的玉米燃料乙醇低能耗生产新工艺,采用了低温液化、浓醪同步糖化间歇发酵、三塔压差精馏与分子筛脱水工艺和全厂各工段的废热进行余热回收技术,目前已经成功应用于多家燃料乙醇生产企业.以黑龙江鸿展生物科技股份有限公司已经投产的30万吨级燃料乙醇工程项目为例,对比分析了新工艺与传统工艺在技术特点、能耗、产品质量等方面的差...     

Investigation of the combustion of neat cottonseed oil or its neat bio-diesel in a HSDI diesel engine by experimental heat release and statistical analyses

An experimental study is conducted to evaluate the effects of using neat cottonseed oil or its neat ME (methyl ester) bio-diesel, on the combustion behavior of a standard, high speed, direct injection (HSDI), ‘Hydra’ diesel engine located at the authors’ laboratory. Combustion chamber and fuel injection pressure diagrams are obtained at medium and high load using a developed, high-speed, data acquisition and processing system. A heat release analysis of the experimentally obtained cylinder pressure diagrams is developed and used. Plots of histories in the combustion chamber of the heat release rate and other related parameters reveal some interesting features, which shed light into the combustion mechanism when using these bio-fuels. These results, combined with the differing physical and chemical properties of the bio-fuels between themselves and against those for the diesel fuel, which constitutes the baseline fuel, aid the correct interpretation of the observed engine behavior performance- and emissions-wise. Moreover, the possible existence of cyclic (combustion) variability is examined as reflected in the pressure indicator diagrams, by analyzing for the maximum pressure and its rate, and the dynamic injection timing and ignition delay, by using statistical analysis for averages, standard deviations and probability density functions. The key results are that with the use of these bio-fuels against the neat diesel fuel case, the ignition delay is hardly affected, the fuel injection pressure diagrams are very slightly advanced accompanied with higher injection pressures, maximum cylinder pressures remain the same with the vegetable oil and slightly increased with the bio-diesel, maximum cylinder pressure rates are increased with the bio-diesel and decreased with the vegetable oil, while the cyclic irregularity is not affected with these bio-fuels remaining at the acceptable neat diesel fuel case levels.     

酒精产业链的循环经济模式

以可再生资源玉米为原料,生产出玉米油、燃料乙醇、蛋白饲料、乙醛、食品添加剂冰醋酸、沼气、CO2等多种产品,实现了产品多层次增值,强化了废物资源化利用,开发了具有高附加值食用化工产品。实现了生产、环保、资源再利用的持续发展,达到了循环经济所倡导的＂资源-产品-资源再生＂的物质循环流动,既减轻了环境污染,又有可观的经济效益。     

A life cycle assessment of advanced biofuel production from a hectare of corn

Conventional agricultural life cycle assessments (LCAs) measure greenhouse gas (GHG) emissions for biofuel pathways as the amount of carbon dioxide equivalent emitted per unit of energy provided by the pathway (i.e. gCO₂e/MJ). This measure of GHG emissions, as computed by the Environmental Protection Agency (EPA) is then used to determine the extent to which the corresponding biofuel pathway complies with the GHG emission standards set forth by the Energy Independence and Security Act (EISA) of 2007. Under current legislation, ethanol produced from corn grain is prohibited from qualifying as an advanced biofuel, even if it were to meet the GHG emission standards. This paper proposes a measure of GHG emissions based on a unit of land rather than the energy provided by a biofuel pathway utilizing only one feedstock. A hectare of corn thus provides two feedstocks for the biofuel pathway considered here; corn grain is used for production of ethanol while corn stover is subjected to fast pyrolysis for production of biochar and bio-oil. The bio-oil is then subsequently upgraded to a fuel suitable for use as a drop in fuel in internal combustion engines. A LCA of this pathway is conducted and it is found that such a pathway generates a 52.1% reduction in GHG emissions. This is a reduction that is sufficient to qualify the combined output of a hectare of corn as an advanced biofuel if the current restriction in EISA were removed.     

液态生物质燃料重整及其在固体氧化物燃料电池中的应用

固体氧化物燃料电池（soild oxide fuel cell,SOFC）是一种清洁高效的发电装置,它可以利用氢气或碳氢燃料发电。液态生物质燃料是一种可再生碳氢燃料,它通过将生物质进行快速催化热解后,经过进一步催化加工制得,主要包括生物甲醇、生物乙醇、生物柴油及其副产物生物甘油等,将SOFC与液态生物质燃料结合,具有便携、清洁和高效等优点。本文分析了包括生物甲醇、生物乙醇、生物柴油以及生物甘油在内的液态生物质燃料的重整研究及其在SOFC中的应用进展,包括重整转化机理与效率、产物选择性、应用于发电存在的优势与难题等。通过对液态生物质燃料进行催化重整,可有效抑制SOFC直接使用液态生物质燃料发电存在的阳极积炭失活现象,从而提高发电效率,延长SOFC使用寿命。总结了目前液态生物质燃料直接用于SOFC发电的研究进展,提出了未来的研究方向,以期提高液态生物质燃料在SOFC中的利用效率和稳定性。