封闭式光生物反应器工业设计选型思考

研制可应用于中试规模和工业规模的光生物反应器,是海藻生产生物柴油的核心问题,在小试阶段正确选择光生物反应器模型方案,是决定海藻生物柴油项目是否能够获得成功的关键。本文对全球研发海藻生物柴油最具代表性公司的各类光生物反应器,以及其它常用于实验室或小试试验的多种光生物反应器,在工业上应用的可行性进行了较全面分析,为拟投资海藻生物柴油的企业在光生物反应器工业设计选型时提供参考。     

海藻生物柴油工厂海藻油生产系统设计思考

利用封闭式光生物反应器进行工业化的连续生产获得大量富含脂质的海藻,从中提取的海藻油能够满足生物柴油厂生产规模的需要,是生产海藻生物柴油的核心问题。文章对设计海藻生物柴油厂海藻油生产系统的工艺流程、各单元系统的功能和工艺要求进行了较全面的论述,为拟投资海藻生物柴油的企业在设计海藻油生产系统时提供参考。     

海藻生物柴油市场竞争力分析

介绍了国际上部分学者对海藻生物柴油生产成本的研究结果,重点分析了利用封闭式光生物反应器生产海藻生物柴油的成本。文章指出,海藻生物柴油工厂建设投资形成的折旧费用和从工业锅炉烟道尾气回收CO2的成本,是决定海藻生物柴油生产成本最主要的两个因素,提出了提高海藻生物柴油市场竞争力的措施。     

两步法光生物反应器海藻生长系统设计思考

对国际上最具代表性的各类型光生物反应器的原理进行了分析比较。用光生物反应器培养海藻,在实现高产的过程中,存在着提高海藻细胞体内蛋白质和碳水化合物含量与提高细胞体内油脂含量的矛盾,提出了两步法光生物反应器海藻生长系统的设计思路,解决了光生物反应器中海藻生长和富集油脂的矛盾。在工业上采用两步法设计光生物反应器系统,可以实现海藻的工业化连续生产。     

海藻基生物柴油最新进展

荷兰AlgaeLinkNV公司是欧洲可替代燃料业界的领头羊之一。该公司最近宣布，已开发出专利海藻光生物反应器系统（photobioreactor systems for algae）。此系统目前是世界上唯一一个不用预制管制造、而是用特制的UV防护透明薄片制成的生产生物柴油的系统。     

海藻基生物柴油最新进展

荷兰AlgaeLinkNV公司是欧洲可替代燃料业界的领头羊之一。该公司最近宣布，已开发出专利海藻光生物反应器系统（photobioreactor systems for algae）。此系统目前是世界上唯一一个不用预制管制造、而是用特制的UV防护透明薄片制成的生产生物柴油的系统。     

浅谈海藻生物柴油的研发状况

叙述了美国、澳大利亚及中国从海藻中提取生物柴油的研发状况,指出,发展从海藻中提取生物柴油的未来发展可促进CO2的消化,实现碳封存、获得更多的副产品及培养更优质的藻类品种。     

微藻生物柴油发展与产油微藻资源利用

生物柴油作为目前全世界正积极推进的可再生能源项目,与清洁核能、风能、光伏发电等将成为人类21世纪的主要能源构成.产油微藻作为生产生物柴油的原料与其他原料相比具有较大优势,在解决成本及生产环节的瓶颈问题后,必将成为生物柴油的主要原料来源.文章探讨了生物柴油的研究现状和微藻生物柴油的优势:微藻商业化生产的主要方式:开放式跑道池、管道式光生物反应器的特点;微藻生物柴油产业链的形成及对促进生物柴油产业商业化的影响.     

第二代和第三代生物燃料发展现状及启示

第二代生物乙醇以生物质为原料,包括纤维素乙醇和纤维素生物汽油两种产品。目前已建有示范装置和/或工业装置的纤维素乙醇生产技术包括硫酸/酶水解-发酵技术、硫酸水解-发酵技术、酸水解-发酵-酯化-加氢技术、酶水解-发酵技术。业内专家认为,用酶替代硫酸水解是纤维素乙醇生产的发展方向。目前已经和准备进行示范装置试验的纤维素生物汽油生产技术包括快速热解-加氢改质技术和BioForming技术。第二代生物柴油主要以动植物油脂为原料,通过催化加氢生产非脂肪酸甲酯生物柴油,它是理想的优质柴油调合组分。生产第二代生物柴油的加氢技术包括加氢脱氧、回收丙烷和其他轻烃气体、脱水、异构化和裂化、蒸馏等5个步骤,主要有NExBTL可再生柴油生产技术、Ecofining绿色柴油生产技术、Haldor Topsoe可再生柴油生产技术、EERC可再生柴油生产技术。第三代生物燃料有两种:一种是以海藻油为原料生产乙醇、丁醇、喷气燃料和柴油,海藻培养(生长)和萃取海藻油是核心步骤,目前尚处于初期阶段;另一种是以生物质原料通过气化合成生产汽油、喷气燃料和柴油,重点是开发生物质气化技术,降低生产成本。我国应借鉴国外发展第二代和第三代生物燃料的做法,把技术开发工作做深做细做透,搞清楚原料的供应情况;目前我国生物柴油主要采用酯交换法生产脂肪酸甲酯,应考虑开发和采用加氢法生产第二代生物柴油,并努力扩大除麻风果油以外的原料来源;同时应加大海藻生物燃料和生物质气化合成生物燃料的开发力度。     

光生物反应器倾斜度对露天培养藻类生物质产率的影响

一天内投射到环形管光生物反应器上的光子通量密度分布剖面，可通过使生物反应器与水平面呈角度倾斜而改变。中午，光子通量密度随倾角增大而降低，而在清晨和傍晚则随倾角增大而增加。呈一定角度倾斜的生物反庆占地面积较小，倾斜80°的生物反应器，单位土地面积每天生物质产率（130生物质／m^2土地）约为地平位置上可获产量（21g生物质／m^2土地）的6倍。生克小球藻细胞所含的准稳态叶绿素为36－63mg。本研究未观测到光对最大光合能力的抑制作用。     

Economic evaluation of algae biodiesel based on meta-analyses

The objective of this study is to elucidate the economic viability of algae-to-energy systems at a large scale, by developing a meta-analysis of five previously published economic evaluations of systems producing algae biodiesel. Data from original studies were harmonised into a standardised framework using financial and technical assumptions. Results suggest that the selling price of algae biodiesel under the base case would be $5.00–10.31/gal, higher than the selected benchmarks: $3.77/gal for petroleum diesel, and $4.21/gal for commercial biodiesel (B100) from conventional vegetable oil or animal fat. However, the projected selling price of algal biodiesel ($2.76–4.92/gal), following anticipated improvements, would be competitive. A scenario-based sensitivity analysis reveals that the price of algae biodiesel is most sensitive to algae biomass productivity, algae oil content, and algae cultivation cost. This indicates that the improvements in the yield, quality, and cost of algae feedstock could be the key factors to make algae-derived biodiesel economically viable.     

Importance of biodiesel as transportation fuel

The scarcity of known petroleum reserves will make renewable energy resources more attractive. The most feasible way to meet this growing demand is by utilizing alternative fuels. Biodiesel is defined as the monoalkyl esters of vegetable oils or animal fats. Biodiesel is the best candidate for diesel fuels in diesel engines. The biggest advantage that biodiesel has over gasoline and petroleum diesel is its environmental friendliness. Biodiesel burns similar to petroleum diesel as it concerns regulated pollutants. On the other hand, biodiesel probably has better efficiency than gasoline. One such fuel for compression-ignition engines that exhibit great potential is biodiesel. Diesel fuel can also be replaced by biodiesel made from vegetable oils. Biodiesel is now mainly being produced from soybean, rapeseed and palm oils. The higher heating values (HHVs) of biodiesels are relatively high. The HHVs of biodiesels (39–41 MJ/kg) are slightly lower than that of gasoline (46 MJ/kg), petrodiesel (43 MJ/kg) or petroleum (42 MJ/kg), but higher than coal (32–37 MJ/kg). Biodiesel has over double the price of petrodiesel. The major economic factor to consider for input costs of biodiesel production is the feedstock, which is about 80% of the total operating cost. The high price of biodiesel is in large part due to the high price of the feedstock. Economic benefits of a biodiesel industry would include value added to the feedstock, an increased number of rural manufacturing jobs, an increased income taxes and investments in plant and equipment. The production and utilization of biodiesel is facilitated firstly through the agricultural policy of subsidizing the cultivation of non-food crops. Secondly, biodiesel is exempt from the oil tax. The European Union accounted for nearly 89% of all biodiesel production worldwide in 2005. By 2010, the United States is expected to become the world's largest single biodiesel market, accounting for roughly 18% of world biodiesel consumption, followed by Germany.     

Effect of outdoor conditions on the growth and lipid accumulation of six green algae

Microalgae are considered as an alternative feedstock for producing biodiesel. In this study, six oil-producing algae were cultivated with natural sunlight outdoors. The highest lipid content, biomass productivity, and lipid productivity were 29.99%, 208.42 mg/l/d, and 69.84 ml/d, respectively. In addition, the photosynthetic efficiency of PS II (Fv/Fm) was kept high during the cultivation and the preferred fatty acids (C16–C18) for producing biodiesel were more than 95% of total fatty acids for all of the strains.     

Recent trends,opportunities and challenges of biodiesel in Malaysia: An overview

Energy supply and its security issues have been the topic of interest lately. With growing environmental awareness about the negative implications brought by excessive usage of fossil fuels, the race for finding alternative energy as their substitutions is getting heated up. For now, renewable energy from biodiesel has been touted as one of the most promising substitutions for petroleum-derived diesel. Combustion of biodiesel as fuel is more environment-friendly while retaining most of the positive engine properties of petroleum-derived diesel. Production of biodiesel is also a proven technology with established commercialization activities. The huge potential of biodiesel coupled with the abundance of palm oil which is one of the most cost-effective feedstocks for biodiesel is responsible for the pledging of Malaysia to become the leading producer of high quality biodiesel in the region. Currently, total approved installed capacity of biodiesel production in Malaysia equals to almost 92% of the world biodiesel production output in 2008. While Malaysia does indeed possessed materials, technologies and marketing superiority to vie for that position, many more challenges are still awaiting. The price restriction, provisions controversy, escalating non-tariff trade barriers and negligible public support need to be addressed appropriately. In this review, Malaysia's previous and current position in global biodiesel market, its future potential towards the prominent leading biodiesel status and major disrupting obstacles are being discussed. The feasibility of utilizing algae as the up-and-coming biodiesel feedstock in Malaysia is also under scrutiny. Lastly, several recommendations on the roles played by three major forces in Malaysia's biodiesel industry are presented to tackle the shortcomings in achieving the coveted status by Malaysia. It is hope that Malaysia's progress in biodiesel industry will not only benefit itself but rather as the role model to catalyst the development of global biofuels industry as a whole.     

Emission analysis of Azolla methyl ester with BaO nano additives for IC engine

The aim of this work is to decrease emissions in diesel engines fueled with diesel and algae biodiesel blends and also addition of BiO nanoparticles. Azolla algae can be used to produce biodiesel, because of high oil content. The biodiesel was prepared by using Azolla algae non-edible oil through transesterification process. In the present study, the BaO nano additives into the algae oil-based methyl ester blend and its diesel blends are analyzed the emission characteristic at different load. Addition of BaO nanoparticle was a strategy to reduce emission (CO, HC, and O₂) of the biodiesel.     

Emission analysis of Azolla methyl ester with Bi2O3 nano additives for IC engine

This work investigates the effect of using Bi₂O₃ nanoparticles at a different proportion of Azolla algae methyl ester in a four-stroke single cylinder diesel engine. Azolla algae can be used to produce biodiesel, because of high oil content. Biodiesel is developed by the transesterification of oil. In the present study, the Bi₂O₃ nano additives into the oil-based methyl ester blend and its diesel blends are analyzed the emission characteristic at different load. Addition of Bi₂O₃ nanoparticle is a strategy to reduce emission (CO, HC and smoke) of the biodiesel.     

Liquid biofuels potential and outlook in Iran

Iran’s diversity of terrain and climate enables cultivation of a variety of energy crops suitable for liquid biofuels production. In Iran, the easily and readily available biofuel feedstock today for production of bioethanol is molasses from sugar cane and sugar beet. There is also about 17.86 million tons of crops waste from which nearly 5 billion liters of bioethanol could be produced annually. This amount of bioethanol is sufficient to carry out E10 for spark ignition engine vehicles in Iran by 2026. There is also enormous potential for cultivation of energy plants such as cellulosic materials and algae. Iran has 7%of its area covered with forest products which are suitable sources for liquid biofuels such bioethanol and biodiesel. Iran also has a long tradition of fishing in Caspian Sea and Persian Gulf with about 3200 km coastline and on inland rivers. The produced fish oil and other plant oils such as palm tree, jatropha, castor plant and algae are suitable biodiesel feedstock. Out of 1.5 million tons of edible cooking oil consumed in Iran annually, about 20% of it can be considered as waste, which is suitable biodiesel feedstock.This quantity along with the other possible potential feedstock are favorable sources to carry out B10 step by step until 2026.     

Algae as a sustainable energy source for biofuel production in Iran: A case study

Algae can be converted directly into energy, such as biodiesel, bioethanol and biomethanol and therefore can be a source of renewable energy. There is a growing interest for biodiesel production from algae because of its higher yield non-edible oil production and its fast growth that does not compete for land with food production. About 50% of algae weight is oil that this lipid oil can be used to make biodiesel. Algae is capable of yielding 30 times more oil per acre than the crops currently used in biodiesel production. Processes for biodiesel production from algae-oil are similar to food and non-food crops derived biodiesel processes. Because of disadvantages of fossil fuels, renewable energy sources are getting importance for sustainable energy development and environmental protection. Among the renewable sources, Iran has high biofuel energy potential. The Iranian government is considerable attention to the utilization of renewable energy, especially biofuels. Iran has enough land in order to algae cultivation that does not compete with food production. A salt lake (Lake Orumieh) in Iran's West Azarbaijan province, Maharlu salt lake in Iran's Fars province, Qom salt lake in Iran's Qom province have given rise to a new species of algae for biofuel. Algae are frequent in the shallow-marine lime stones in Zagros Mountains in north of Fars province. Greenish blooms of algae can be seen in the Persian Gulf and Caspian Sea, south and north of Iran respectively. This study presents a brief introduction to the resource, status and prospect of algae as a sustainable energy source for biodiesel production in Iran. The main advantages of using algae for biodiesel production in Iran are described.     

Potential and challenges for large-scale application of biodiesel in automotive sector

Biodiesel is receiving serious attention globally as a potential alternative fuel for replacing mineral diesel, partially or fully. In this review paper, most prominent methods of biodiesel production commercially, life-cycle analysis and economic issues related to biodiesel, engine performance, combustion and emission characteristics including particulate, engine compatibility issues and effect of biodiesel usage on engine component wear and lubricating oil are comprehensively discussed. Majority of biodiesel produced globally is via base-catalyzed transesterification process since this is a low temperature and pressure process, having high conversion rates without intermediate steps, and it uses inexpensive materials of construction for the plant. Catalyst types (alkaline, acidic or enzymatic), catalyst concentration, molar ratio of alcohol/oil, reaction temperature, moisture content of reactants, and free fatty acid (FFA) content of oil are the main factors affecting biodiesel (ester) yield from the transesterification process. Substantial reduction in particulate matter (PM), total hydrocarbons (THC) and carbon monoxide (CO) emissions in comparison to mineral diesel, and increased brake specific fuel consumption (BSFC) and oxides of nitrogen (NO_X) emissions are reported by most researchers using unmodified compression ignition (CI) engines. This review covers several aspects, which are not covered by previous review articles, such as effect of biodiesel on unregulated emissions, effect of biodiesel on carbon deposits, wear of key engine components, and lubricating oil in long-term endurance studies. It emerges from literature review that even minor blends of biodiesel help control emissions and ease pressure on scarce petroleum resources without sacrificing engine power output, engine performance and fuel economy. This review underscores that future studies should focus on optimization of fuel injection equipment and hardware modifications to develop dedicated biodiesel engines, improve low temperature performance of biodiesel fuelled engines, develop new biodiesel compatible lubricating oil formulations and special materials for engine components before implementing large-scale substitution of mineral diesel by biodiesel globally.     

可再生绿色能源生物柴油的开发与利用

在能源安全、环境保护和拓展新经济产业链的大背景下,生物柴油产业应运而生,在欧美等国已蓬勃发展。中国能源总量和结构任人担忧,急待开发可替代的具有可再生性绿色能源一生物柴油,但中国的生物柴油产业不容乐观,因而必须站在战略高度采取应对之策,制定近期、中期、远期生物产业发展规划。