Biomass and lipid productivities of marine microalgae isolated from the Persian Gulf and the Qeshm Island

In this work, the screening of 147 microalgal strains from the Persian Gulf and the Qeshm Island (Iran) were done in order to choose the best ones, in terms of growth (biomass) rate and lipid content for biodiesel production. A methodology, combining experiments in lab-scale and pilot plant (open pond) used to produce and evaluate biomass and lipid productivity is presented for the systematic investigation of the potential of different microalgae species. The culture conditions, including photo flux (180 ??E m⁻² s⁻¹), photoperiod (12 h light/dark), temperature (25 °C), pH (≈8), air (carbon dioxide) and growth medium, were kept constant for all experiments. Microalgae were screened in two stages using optical density (for evaluation of biomass concentration) and Nile red and gas chromatography (for determination of lipid content and fatty acid fractions). In general, maximum specific growth rate and the maximum biomass productivity were obtained after 8-12-day culture. Nannochloropsis sp. and Neochloris sp. were selected from the marine microalgal culture collection, due to their high biomass (50 and 21.7 g L⁻¹, respectively) and oil content (52% and 46%, respectively). If the purpose is to produce biodiesel only from one species, Nannochloropsis sp. presented the most adequate fatty acid profile, namely linolenic and other polyunsaturated fatty acids. However, the microalgae Chlorella sp. can also be used if associated with other microalgal oils. In addition, selected strains could be potent candidates for commercial production in the open pond culture.     

Biomass from agriculture in small-scale combined heat and power plants - A comparative life cycle assessment

Biomass produced on farm land is a renewable fuel that can prove suitable for small-scale combined heat and power (CHP) plants in rural areas. However, it can still be questioned if biomass-based energy generation is a good environmental choice with regards to the impact on greenhouse gas emissions, and if there are negative consequences of using of agricultural land for other purposes than food production.In this study, a simplified life cycle assessment (LCA) was conducted over four scenarios for supply of the entire demand of power and heat of a rural village. Three of the scenarios are based on utilization of biomass in 100 kW (e) combined heat and power (CHP) systems and the fourth is based on fossil fuel in a large-scale plant. The biomass systems analyzed were based on 1) biogas production with ley as substrate and the biogas combusted in a microturbine, 2) gasification of willow chips and the product gas combusted in an IC-engine and 3) combustion of willow chips for a Stirling engine. The two first scenarios also require a straw boiler.The results show that the biomass-based scenarios reduce greenhouse gas emissions considerably compared to the scenario based on fossil fuel, but have higher acidifying emissions. Scenario 1 has by far the best performance with respect to global warming potential and the advantage of utilizing a byproduct and thus not occupying extra land. Scenario 2 and 3 require less primary energy and less fossil energy input than 1, but set-aside land for willow production must be available. The low electric efficiency of scenario 3 makes it an unsuitable option.     

Biomass supply from conventional forestry

The work conducted under the IEA Bioenergy Agreement Task VI Biomass Supply from Conventional Forestry in the period 1989 – 1991 is described. The achievements of the Task have been a greater appreciation of the wood fuel supply chain by participants, an increased level of coordination and cooperative research, a number of spin-off cooperative projects, and an increased industrial involvement in the cooperation.     

Hazardous Emissions from Combustion of Biomass

Abstract

The main objective of this study is to identify the possible hazerdous emissions deriving from uncontrolled and incomplete combustions of biomass fuels that are reviewed based on the results of some investigations. Biomass combustion is a contributor of toxic air pollutants, particulate matter (PM), and greenhouse gases. PM emissions and detrimental metal emissions from biomass combustion, emissions of polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) from the combustion of different biomass and solid wastes are reviewed.     

生物质液体燃料的制造

用生物质制造液体燃料是生物质能开发利用的重要课题,本文描述了近年公告的这方面国外专利技术。     

生物质气化制氢的模拟

以秸秆为研究对象,利用Aspen P lus软件建立气化反应器模型,对生物质气化制氢进行模拟计算.探讨不同反应条件,包括气化温度、生物质与蒸汽质量配比以及催化剂对富氢气体成分的影响.计算结果表明,未加催化剂条件下,采用生物质蒸汽气化技术可获得体积分数为6000/以上的富氢燃料气,增大蒸汽与生物质质量配比有利于氢气产率的提高;添加CaO、MgO催化剂可较大幅度地提高氢气产率,氢气体积分数最大可达到9400/,其中CaO对生物质气化制氢过程的催化作用非常显著.     

Biomass co-firing options on the emission reduction and electricity generation costs in coal-fired power plants

Co-firing offers a near-term solution for reducing CO₂ emissions from conventional fossil fuel power plants. Viable alternatives to long-term CO₂ reduction technologies such as CO₂ sequestration, oxy-firing and carbon loop combustion are being discussed, but all of them remain in the early to mid stages of development. Co-firing, on the other hand, is a well-proven technology and is in regular use though does not eliminate CO₂ emissions entirely. An incremental gain in CO₂ reduction can be achieved by immediate implementation of biomass co-firing in nearly all coal-fired power plants with minimum modifications and moderate investment, making co-firing a near-term solution for the greenhouse gas emission problem. If a majority of coal-fired boilers operating around the world adopt co-firing systems, the total reduction in CO₂ emissions would be substantial. It is the most efficient means of power generation from biomass, and it thus offers CO₂ avoidance cost lower than that for CO₂ sequestration from existing power plants. The present analysis examines several co-firing options including a novel option external (indirect) firing using combustion or gasification in an existing coal or oil fired plant. Capital and operating costs of such external units are calculated to determine the return on investment. Two of these indirect co-firing options are analyzed along with the option of direct co-firing of biomass in pulverizing mills to compare their operational merits and cost advantages with the gasification option.     

废弃生物质的开发利用

评述了利用废弃生物质资源的重要性,列出了国内外现有的开发利用手段,详细阐述了生物降解和热化学转化等新技术趋势。     

生物质颗粒冷态致密成型技术

生物质能是唯一直接来自于太阳能并可储存运输的可再生能源。与传统化石类能源相比，它具有分布范围广、数量大、可再生等优点。生物质颗粒燃料冷态致密成型技术，是一种重要的生物质资源化利用基础技术之一，可有效地解决储运瓶颈。该项技术在国外已得到了较大的发展，在我国也有了一定的研究基础，具有很大的发展空间。近年来，我们对不同的生物质冷态致密成型机理进行了深入的研究，用不同种类生物质进行了冷态致密成型试验，深入分析了原料种类、粒度、含水率对颗粒燃烧的成型率、密度、抗碎性及吨料能耗的影响，在此基础上开发出了系列高效生物质颗粒燃料冷态致密成型设备。为生物质颗粒燃料冷态致密成型技术在我国的大规模推广应用奠定了基础。     

Production and Characterization of Bio-Chars from Biomass via Pyrolysis

This article deals with slow pyrolysis of oak wood and agricultural residues such as hazelnut shell and wheat straw at high temperature (950–1250 K) in a cylindrical reactor. The aim of this work is to study the effect of the treatment conditions such as temperature, particle size, and lignin and inorganic matter contents on bio-char yield and reactivity. When the pyrolysis temperature increased, the bio-char yield decreased. A high temperature and smaller particles increase the heating rate resulting in a decreased bio-char yield. The higher lignin content in hazelnut shell results in a higher bio-char yield in comparison with oak wood and wheat straw. Bio-chars from hazelnut shell and wheat straw are more reactive in gasification than bio-chars from oak wood because of the higher ash content. The bio-char obtained are carbon rich, with high heating value and relatively pollution-free potential solid biofuel.     

Life Cycle Cost of Electricity Generation from Biomass Gasifier

India is having more than 500,000 villages of which about 85% have been electrified. But as per RGGVY （Rejiv Gandhi Grammen Vidyutikaran Yojana）, the rate of village electrification is much lower as household connectivity has been fairly low. The rest 15% villages and a larger proportion of households have to be electrified. Villages have been a major concern as cost of electrification is fairly high. The most favored alternative to any kind of users is generation of electricity from diesel generating sets and renewable sources of energy. But the capital cost of renewable energy equipments is fairly high. Gradually, there is a reduction in the prices of these systems due to availability of better technological options and they are becoming competitive to grid electricity. In this paper, an attempt has been made to calculate the cost of production of electricity from stand-alone, off-grid devices biomass gasifiers （both dual fuel and pure gas type） and compare with that of diesel generating sets by using the concept of LCC （life cycle costing） and Homer software. It is found that the cost of per unit electricity generation （kWh） has been always the lowest in comparison to diesel generating sets even if the price of biomass increases to some extent.     

生物质快速热解蒸气的在线催化研究

在固定床上对生物质流化床快速热解产生的蒸气进行了直接催化试验.选用HZSM-5催化剂,探讨了催化温度和催化剂量对催化后产物分布及生物油组分的影响.结果表明:在催化温度为375℃、催化剂量为30 mL时,可获得较高的液相产率(36.4%)、较低的气相产率(20.4%)和焦产率(13.9%).通过分析最佳工况下的生物油组分,发现精制油中含氧量高的有机酸、酯、酮、醛、呋喃等含量明显降低,而含氧量低的小分子酚类及不合氧的烃类含量大幅提高.     

Biomass supply in EU27 from 2010 to 2030

With biomass staying high in the EU political agenda and most of the recent documents acknowledging that it has the potential to make a very significant contribution to reaching the 20% target [7 and 6], the issue of supply in terms of feedstock types, availability constraints and costs in different Member States is set to determine the future technology uptake and market deployment prospects.     

中国农业残余生物质能利用对策研究

生物质能已成为缓解当今能源短缺的重要可再生能源,在研究比较生物质利用技术和中国农业残余生物质资源特点的基础上,分析了中国生物质利用技术的发展潜力和产业化前景,提出了生物质能利用的对策及建议。     

Biomass energy

The Energy Research Advisory Board (ERAB) was asked to prepare an analysis of the state of biomass systems development and use by the yr 2000. The study takes into account research funds and scientific manpower that should be allocated to biomass energy investigations. The analysis and research recommendations emphasize those programs that might make significant contributions to the energy needs of the nation.     

Biomass and lipid production of marine microalgae using municipal wastewater and high concentration of CO2

In order to reduce the cost of the production of microalgae for biodiesel, the feasibility of using the mixture of seawater and municipal wastewater as culture medium and CO₂ from flue gas for the cultivation of marine microalgae was investigated in this study. Effects of different ratios of municipal wastewater and 15% CO₂ aeration on the growth of Nannochloropsis sp. were examined, and lipid accumulation of microalgae was also studied under nitrogen starvation and high light. It was found that optimal growth of microalgae occurred in 50% municipal wastewater, and the growth was further significantly enhanced by aeration with 15% CO₂. When Nannochloropsis sp. cells were transferred from the first growth phase to the second lipid accumulation phase under the combination of nitrogen deprivation and high light, both biomass and lipid production of Nannochloropsis sp. were significantly increased. After 12 days of the second-phase cultivation, the biomass concentration and total lipid content increased from 0.71 to 2.23 g L⁻¹ and 33.8–59.9%, respectively. This study suggests that it is possible to utilize municipal wastewater to replace nutrients in seawater medium and use flue gas to provide CO₂ in the cultivation of oil-bearing marine microalgae for biodiesel.     

由生物质催化裂化新能源的理念

叙述了由生物质转变新能源的理念,生物质转换新能源的现状及必须解决的问题,介绍了＂复相催化＂技术、工艺特点和效益,指出,利用＂复相催化＂技术从污泥、油页岩等生物质中提炼燃油,改变了传统的生产工艺,有望使生物质能源成为未来世界能源的支柱,改变目前能源短缺的问题。     

Methanol from Wood I. Process Principles and Technologies for Producing Methanol from Biomass

A review is presented on the various process routes and reactor types available for producing methanol from biomass via synthesis gas. Advantages and disadvantages of the various gasifiers and gasification process routes are briefly discussed. The commerically most successful methanol from synthesis gas processes are discussed as well because the characteristics of the downstream methanol synthesis process dictate the optimal composition of the synthesis gas to be produced by the upstream gasification process, the optimal operating pressure and the specifications for the intermediate synthesis gas treatment section.     

美国的生物质能计划

叙述了美国生物质能的发展以及其具体的技术规划和项目管理。     

生物质气化气中焦油非催化裂解实验研究

生物质气化是一种环境友好的新能源利用技术,焦油作为生物质气化的副产物,是限制气化技术发展的主要因素.试验针对生物质气化产出气中焦油在700～1 000℃裂解温度区间的裂解特性进行了分析,并提出了焦油裂解产气率的概念.试验表明,焦油裂解气可以成为生物质气化气的有效的能量补充,而且随着裂解温度的升高,焦油裂解产气率增加,焦...