Life cycle energy and environmental benefits of generating electricity from willow biomass

Biomass is a key renewable energy source expected to play an important role in US electricity production under stricter emission regulations and renewable portfolio standards. Willow energy crops are being developed in the northeast US as a fuel source for increasing biomass energy and bioproduct demands. A life cycle inventory is presented that characterizes the full cradle-to-grave energy and environmental performance of willow biomass-to-electricity. A willow biomass production model is developed using demonstration-scale field experience from New York. Scenarios are presented that mimic anticipated cofiring operations, including supplemental use of wood residues, at an existing coal-fired generating facility. At a cofiring rate of 10% biomass, the system net energy ratio (electricity delivered divided by total fossil fuel consumed) increases by 8.9% and net global warming potential decreases by 7–10%. Net SO₂ emissions are reduced by 9.5% and a significant reduction in NO_x emissions is expected. In addition, we estimate system performance of using willow biomass in dedicated biomass gasification and direct-fired generating facilities and demonstrate that the pollution avoided (relative to the current electricity grid) is comparable to other renewables such as PV and wind.     

Social cost-benefit analysis of electricity interconnector investment: A critical appraisal

This paper examines the economic analysis (social cost-benefit analysis) underlying two decisions to build an interconnector (NorNed and the East–West interconnector) in Europe. The main conclusion is that current interconnector and transmission investment decisions in Europe are unlikely to maximize social welfare. The arguments are as follows. (i) It is unclear how much demand for transmission capacity and interconnectors actually exists, and thus the benefits of investment are unclear. (ii) Both analyses underlying the investments studied are incorrect, to the point where, in one case, even the sign may be wrong. (iii) The main criticism concerns the fact that they do not take the resulting changes in generator investment plans into account and ignore the (potential) benefits of increased competition. (iv) Several smaller issues can be improved, such as the discount rate used. (v) Decisions at the European level are taken very differently, and approval may depend on which authority grants approval. (vi) Interconnector decisions receive the most attention, although most money goes to transmission investments. Two research recommendations for future improvements are formulated.     

生物质气化发电技术讲座(7)大中型生物质气化发电系统应用实例分析

1 中型生物质气化发电系统。中型生物质气化发电系统一般采用流化床气化工艺，发电规模为400～3000kW。中型生物质气化发电系统在发达国家应用较早，所以技术较成熟，但由于设备造价很高，发电成本居高不下，所以，在发达国家应用极少。近年来，我国开发出了循环流化床气化发电系统，由于该系统有较好的经济性，所以在我国推广很快，已经成为国际上应用最多的中型生物质气化发电系统。     

Sustainability considerations for electricity generation from biomass

The sustainability of electricity generation from biomass has been assessed in this work according to the key indicators of price, efficiency, greenhouse gas emissions, availability, limitations, land use, water use and social impacts. Biomass produced electricity generally provides favourable price, efficiency, emissions, availability and limitations but often has unfavorably high land and water usage as well as social impacts. The type and growing location of the biomass source are paramount to its sustainability. Hardy crops grown on unused or marginal land and waste products are more sustainable than dedicated energy crops grown on food producing land using high rates of fertilisers.     

A scheme for generating electricity using gravitational energy

A practical scheme for generating electricity using gravitational energy is presented. The scheme uses a set of massive underground spinning wheels, each wheel being fitted with a mechanism to receive and transmit gravitational torque pulses from a passing vehicle to keep the wheels in motion. Each wheel in combination with an appropriate gear system then acts as the prime mover of an alternator which produces the electricity. Design formulae relating to the power gain and the overall efficiency of the energy system are then developed. The numerical results presented in the paper indicate that a power gain of as high as 10 and an associated efficiency of conversion close to 92% can be easily achieved with a reasonable design of the system.     

A model for generating household electricity load profiles

Electricity consumption data profiles that include details on the consumption can be generated with a bottom‐up load models. In these models the load is constructed from elementary load components that can be households or even their individual appliances. In this work a simplified bottom‐up model is presented. The model can be used to generate realistic domestic electricity consumption data on an hourly basis from a few up to thousands of households. The model uses input data that is available in public reports and statistics. Two measured data sets from block houses are also applied for statistical analysis, model training, and verification. Our analysis shows that the generated load profiles correlate well with real data. Furthermore, three case studies with generated load data demonstrate some opportunities for appliance level demand side management (DSM). With a mild DSM scheme using cold loads, the daily peak loads can be reduced 7.2% in average. With more severe DSM schemes the peak load at the yearly peak day can be completely levelled with 42% peak reduction and sudden 3 h loss of load can be compensated with 61% mean load reduction. Copyright © 2005 John Wiley & Sons, Ltd.     

An exploratory game-theoretic analysis of biomass electricity generation supply chain

This study proposes a game-theoretic approach to model and analyze the process of utilizing biomass for power generation considering three players: distributor, facility developer, and participating farmer. We characterize the Nash equilibrium of the sequential game and discuss its features. A special attention is devoted to the analysis of the impact of incentives and initial target on the equilibrium, in which the biomass is part of electricity production.     

Goal programming model for sustainable electricity production from biomass

In this paper, we present a goal programming model for block level energy planning in order to make a block self‐sufficient in electricity consumption, which includes the commercial energy consumption goal, the goal of generating electricity from biomass and food production goals with linear constraints on the available sources such as human power, animal power, tractor power, land area and on the requirement of the block such as cooking energy, lighting energy and energy for other operations, such as fodder for animal population. We try to achieve these goals through proper allocation of land for different crops. After reformulating the developed goal programming model into a linear programming format, we use the HYPER LINDO software package to solve it in a Pentium‐based IBM‐PC compatible computer system. The developed model is solved for a typical Indian block, namely Nilakkottai Block in Tamil Nadu, India. The model solution shows that the goal of generating electricity from biomass is achieved, the commercial energy consumption goal and pulses requirement goal are under‐achieved and the sugar requirement goal is over‐achieved. Furthermore, the cereal, vegetable and oilseed production goals are achieved. Copyright © 2000 John Wiley & Sons, Ltd.     

“蓝天白煤”——风能在发电领域的应用研究

介绍了欧、美、日等发达国家风能利用现状。分析了辽宁省风力发电基本状况 ,提出了风力发电应解决的主要问题     

我国生物质与煤混烧发电的可行性分析

通过对生物质发电政策法规、混烧发电优势、原料保障的分析,对生物质混烧发电技术方案进行讨论,并结合一些实例,分析得出生物质混烧发电适合我国国情,应大力发展.     

Enhanced electricity generation using biomass materials

Renewable energy is a promising alternative solution for the energy requirements because it is clean and environmentally safe. Projections are important tools for long-term planning and policy settings. According to estimates, by 2040 approximately half of the global energy supply would be from renewable sources. Biomass can be converted into electric power through several methods. Heat is used to thermochemically convert biomass into a fuel oil which is then burned like petroleum to generate electricity. Biomass can also be burned directly to produce steam for electricity production or manufacturing processes. One alternative for producing electricity from biomass in a gas turbine is direct combustion of biomass as a primary energy source. Biomass is burned directly to produce steam, the steam turns a turbine which derives a generator thus electricity is generated.     

Decentralized generation of electricity from biomass with proton exchange membrane fuel cell

Biomass can be applied as the primary source for the production of hydrogen in the future. The biomass is converted in an atmospheric fluidized bed gasification process using steam as the gasifying agent. The producer gas needs further cleaning and processing before the hydrogen can be converted in a fuel cell; it is assumed that the gas cleaning processes are able to meet the requirements for a PEM-FC. The compressed hydrogen is supplied to a hydrogen grid and can be used in small-scale decentralized CHP units. In this study it is assumed that the CHP units are based on low temperature PEM fuel cells. For the evaluation of alternative technologies the whole chain of centralized hydrogen production from biomass up to and including decentralized electricity production in PEM fuel cells is considered.Two models for the production of hydrogen from biomass and three models for the combined production of electricity and heat with PEM fuel cells are built using the computer program Cycle-Tempo. Two different levels of hydrogen purity are considered in this evaluation: 60% and 99.99% pure hydrogen. The purity of the hydrogen affects both the efficiencies of the hydrogen production as well as the PEM-FC systems. The electrical exergy efficiency of the PEM-FC system without additional heat production is calculated to be 27.66% in the case of 60% hydrogen and 29.06% in the case of 99.99% pure hydrogen. The electrical exergy efficiencies of the whole conversion chain appear to be 21.68% and 18.74%, respectively. The high losses during purification of the hydrogen gas result in a higher efficiency for the case with low purity hydrogen. The removal of the last impurities strongly increases the overall exergy losses of the conversion chain.     

DF4B型机车辅助发电跳固定发电原因分析

通过对机车出现的辅助发电跳固定发电的原因分析,找到了处理这一故障的方法,并提出了相应的措施及建议,使得CET、DYT烧损故障大大减少。     

斜坡式热气流发电试验模型的设计

分析了斜坡式热气流太阳能发电的可行性,介绍了斜坡式热气流发电的组成及基本原理.根据依山而建斜坡式热气流发电系统的思想,设计了一个高4m、宽1.5 m的试验模型.用有机玻璃做透明盖板材料;用铁板代替山体,在其后面设置了用于调控温度的电阻丝700W/m2.阐述了确定该试验模型各部分比例和结构参数的依据.对设计的试验模型进行了评价:与传统的塔式发电模型相比,该模型具有集热效率高、造价低的优点.     

Advanced exergetic analysis of a novel system for generating electricity and vaporizing liquefied natural gas

LNG technology has been in use since the 1960s. During the last 20 years the total cost of LNG technology has decreased by 30% due mainly to improvements of the liquefaction process and shipping. However, the regasification system has not been significantly improved. The paper presents a detailed advanced exergetic analysis of a novel co-generation concept that combines LNG regasification with the generation of electricity. The analysis includes splitting the exergy destruction within each component into its unavoidable, avoidable, endogenous and exogenous parts as well as a detailed splitting of the avoidable exogenous exergy destruction. The results of the advanced exergetic analysis are confirmed through a sensitivity analysis. Finally, some suggestions for improving the overall system efficiency are developed.     

A review on electricity generation based on biomass residue in Malaysia

Nowadays, biomass is considered as one of the main sources of energy for both developed and developing countries. Malaysia with a large amount of biomass residues as a source of electricity generation is considered as one of the potential countries in this field. This study aims to analyze the potential of recovering energy from major source of biomass residue in Malaysia. For this purpose, the agricultural crop residues and industrial crop waste are investigated. These will contribute substantially to harness a sustainable resource management system in Malaysia to reduce the major disposal problem of biomass residue. The effective use of the waste can supply the required fuel for future electricity generation.     

Influence of biomass addition on electricity harvesting from solid phase microbial fuel cells

In this study, two types of biomass (Acorus calamus leaves and wheat straw) were added to a matrix of sediment and soil inside the anode of solid phase microbial fuel cells (SMFCs) in order to increase their output power. SMFC containing 3% leaves in their sediment had a maximum power density of 195 mW m⁻² in contrast to 4.6 mW m⁻² of that SMFC without leaves. Similarly, SMFC containing 1% wheat straw in their soil environment had a maximum power density of 167 mW m⁻². It suggests that the addition of biomass in appropriate proportions increases contact opportunities between the matrix, the anode and the added biomass, increases organic matter content, and enhances cellulase activity, thus serving as an important method for enhancing output power in SMFCs.     

Decentralized generation of electricity with solid oxide fuel cells from centrally converted biomass

A thermodynamic evaluation of different energy conversion chains based on centralized biomass gasification and decentralized heat and power production by a solid oxide fuel cell (SOFC) has been performed. Three different chains have been evaluated, the main difference between the chains is the secondary fuel produced via biomass gasification. The secondary fuels considered are hydrogen, synthetic natural gas (SNG) and syngas. These fuels are assumed to be distributed through a transport and distribution grid to the micro-combined heat and power (μ-CHP) systems based on a SOFC and a heat pump.     

Wood-fuel biomass from the Madeira River: A sustainable option for electricity production in the Amazon region

The universal provision of electricity remains far from achieved in the Brazilian Amazon, given the geographical obstacles, the dispersion of its inhabitants, the indistinctness of appropriate technologies, and the economic obstacles. Governmental action was taken in 2003 with the creation of the Light for All Program (PLpT), with the goal of bringing electricity to all rural consumers by 2010. In addition, the National Electric Power Agency, ANEEL (Agência Nacional de Energia Elétrica), which is responsible in Brazil for the electrical sector regulation, has issued a determination of compulsory access to electricity by 2015. This study describes research conducted on the Madeira River, in the Brazilian Amazon, where the electric needs of the communities and small towns along the river can be satisfied through the gasification system, using as a renewable feedstock the wood-fuel biomass deposited on the riverbed, derived from natural processes, which the Ministry of Transport is already legally obligated to remove in order to provide safe navigation along the river. The study concludes by comparing the competitiveness of this system to diesel thermoelectric plants, along with its advantages in reducing the emission of greenhouse gases. Our results should help future studies in others areas with similar phenomena.