Assessment of potential biomass energy production in China towards 2030 and 2050

The objective of this paper is to provide a more detailed picture of potential biomass energy production in the Chinese energy system towards 2030 and 2050. Biomass for bioenergy feedstocks comes from five sources, which are agricultural crop residues, forest residues and industrial wood waste, energy crops and woody crops, animal manure, and municipal solid waste. The potential biomass production is predicted based on the resource availability. In the process of identifying biomass resources production, assumptions are made regarding arable land, marginal land, crops yields, forest growth rate, and meat consumption and waste production. Four scenarios were designed to describe the potential biomass energy production to elaborate the role of biomass energy in the Chinese energy system in 2030. The assessment shows that under certain restrictions on land availability, the maximum potential biomass energy productions are estimated to be 18,833 and 24,901?PJ in 2030 and 2050.     

Exploration of the land potential for the production of biomass for energy in the Netherlands

The energy potential for energy crops and biomass residues in the Netherlands is assessed. The analysis explores the possible use of land for biomass production in the future. Various government memorandums and analyses of the expected future land use in various sectors have served as the basis for the assessment of the supply of and the demand for land in the future. In this study the potential supply of agricultural land is based on expected productivity increments in agriculture and assumptions with respect to the future demand for agricultural products. Various future claims for infrastructure, forestry, urban areas and nature are subtracted from the expected supply. The net projected supply of land ranges from zero to 52 000 ha in 2000 to 110 000-250 000 ha in 2015. The supply of agricultural land depends however on a number of supra-national factors, such as the European agricultural policy, world market developments and the agricultural production in the countries in Eastern Europe. Uncertainties remain, therefore, and the projected supply of agricultural land should be considered as a possible scenario based on current trends. If the calculated land potential is used for energy crops like miscanthus and short rotation coppice, this land could contribute 0-10 PJ in 2000 and 27-59 PJ in 2015. Secondary biomass yields, such as those from forestry, agricultural residues, wood from prunings, etc., could contribute a further 34 PJ in 2000, decreasing to approximately 28 PJ in 2015. Taken together these potentials could satisfy 1-1.5% of the energy requirements of the Netherlands in 2000 and 1.5-2.5% in 2015, provided that energy farming is an economically feasible activity for farmers.     

生物质能利用方式的分析比较

简要分析了几种生物质能利用方式的技术性、经济性和社会性特征。通过比较，认为通过热化学法或生化法将生物质转化为液态或气态燃料即可提升生物质能的能量品质，又可大大拓展生物质能的使用范围，是生物质能利用的主要方式。其中，生化法由于其近于零污染的特性而将成为生物质能利用的首选方式。     

Identifying agricultural sites for biomass energy production in Minnesota

This research examines the potential of producing hybrid poplar on location specific marginal agricultural lands in Minnesota. It is assumed that all poplar production would be used to meet biomass energy requirements for two potential 100 MW power plants located in Alexandria and Granite Falls, Minnesota. The delivered fuelwood costs for each power plant are calculated using a cost minimization model. In addition to traditional production and harvesting costs, the model also incorporates landowners opportunity cost of fuelwood production as well as the actual transportation costs associated with supply from each individual analysis area to each power plant. The inclusion of any analysis area as a potential fuelwood supplier is greatly dependent on the interaction and combination of variables such as the opportunity cost, yield rates, and the distance from the power plants. The results show that approximately 40×10³ hectares of land capable of producing about 3.2×10[6] dry Mg of wood would be required to fuel each power plant for a 10 year planning period. The average present value costs of delivered (to the plant gate) fuelwood is about $32 dry Mg⁻¹ for Alexandria and $37 dry Mg⁻¹ for Granite Falls.     

生物质能利用技术比较与分析

生物质能的开发利用可同时解决环境污染和能源短缺问题。分析了生物质能源的特点及其利用现状，并对国内外生物质能利用技术进行了分析与比较，为生物质能利用技术的发展提供参考。     

Renewable energy and the environment in South Africa: A way forward

The need to mitigate the adverse environmental impacts of fossil fuel usage, the volatility of fuel prices and enhancement of national energy security, have largely driven a phenomenal growth, around the world, in renewable energy (RE) generation (particularly grid-connected), over the past two decades. The necessity to apply policy support instruments to promote the dissemination of these technologies is now a universally accepted norm. Different countries and societies depending on the prevailing socio-economic environment draft and apply their policy frameworks differently and debates abound as to which mechanisms should have been most suitable under which circumstance. Most of these debates, however, assume the existence of an intrinsic political environment in favour of the process. In South Africa the current political environment is not very conducive to the development of a sustainable RE industry. This paper explores some of the anomalies and barriers and suggests possible options for a way forward to a viable RE industry in the country.     

发展我国生物质能的战略思考

在研究国内外生物质能的利用和研究现状的基础上,分析了我国生物质能发展过程中存在的一些问题,并对我国生物质能的发展提出合理化的建议。     

The potential biomass for energy production in the Czech Republic

Biomass production is a promising alternative for the Czech Republic's (CZ) agricultural sector. Biomass could cover the domestic bio-energy demand of 250 PJ a⁻¹ (predicted for 2030), and could be exported as bio-fuels to other EU countries. This study assesses the CZ's biomass production potential on a regional level and provides cost–supply curves for biomass from energy crops and agricultural and forestry residues. Agricultural productivity and the amount of land available for energy crop production are key variables in determining biomass potentials. Six scenarios for 2030 with different crop-yield levels, feed conversion efficiencies and land allocation procedures were built. The demand for food and fodder production was derived from FAO predictions for 2030. Biomass potential in the CZ is mainly determined by the development of food and fodder crop yields because the amount of land available for energy crop production increases with increasing productivity of food and fodder crops. In most scenarios the NUTS-3 regions CZ020, 31 and 32 provided the most land for energy-crop production and the highest biomass potentials. About 110 PJ a⁻¹, mostly from agricultural and forestry residues, can be provided from biomass when the present Czech agricultural productivity is maintained. About 195 PJ a⁻¹ (105 PJ from energy crops) can be provided when production systems are optimised with regard to fertilizer regimes and 365 PJ a⁻¹ (290 PJ from energy crops) when the yield level of Dutch agriculture is reached. Costs for woody biomass decrease with increasing plantation yield and range between 2.58 and 4.76 € GJ⁻¹. It was concluded that Czech agriculture could provide enough biomass for domestic demand and for export if agricultural productivity is increased.     

The link between renewable energy production and gross domestic product in Africa: A comparative study between 1980 and 2008

Renewable energy (RE) projects are arguably one of the most important strategies that can be used in the mitigation of climate change impacts. At the same time, RE technologies can generate clean energy and potentially boost the economy of the African continent. It is thus not surprising that recent studies have investigated the relationship between RE and economic growth in some African countries. However, the limitation of these reductionist analytical frameworks is that they can conceal the true regional picture in terms of the link between investments in RE technologies and gross domestic product (GDP). This holistic analysis is important in order to inform regional policies on climate change. The article uses statistical analytic techniques to examine the correlation between RE production and economic growth across different blocks of the African continent between 1980 and 2008. The analysis is between geographical blocks (e.g. Southern Africa, Western Africa, etc.) and between oil and non-oil producing blocks. Generally speaking, while there exists a similar pattern in all the studied blocks in terms of mean, standard deviation and correlation between RE and GDP, a few exceptions can be found. For instance, the rise in RE-GDP correlation from 1992/1993 onwards was conspicuously higher in North Africa and oil-producing countries compared to all the other blocks. Similarly, Southern Africa was the only block where the correlation between RE and GDP was negative throughout the period under review, except 1988, 1989 and 1997 when it was positive.     

天津市农村生物质能利用现状及发展趋势分析

在对天津市农村生物质能实地调研的基础上,对天津市生物质资源量及利用现状进行了分析,表明天津市发展生物质作为农村居民炊事燃料具有较大的发展空间;对当前天津的农村住宅生物质能源利用模式进行了归纳和总结,并对农村生物质能源在项目建设及管理等方面的存在问题进行了探讨。结合我国能源发展现状及天津市"十二五"发展规划,从新农村建设与能源规划的角度统筹考虑,对天津市农村生物质能的发展趋势、利用趋势及生物质发展与城乡规划布局的关系三个方面进行了分析和设想,表明生物质能在新农村建设中的积极作用。     

生物质能源化利用与硫循环

生物质能源化利用可以在一定程度上减少由于燃煤而带来的硫污染问题，同时又有效地处理了农村秸秆废弃物，能够取得能源利用和环境保护的双重效果。     

Renewable energy for sustainable development in Africa: a review

Renewable energy usage in Africa has been reviewed using South Africa, Egypt, Nigeria and Mali as case studies. The various national energy policies of these countries were analysed and areas that require attention to achieve sustainability were highlighted. On the overall, the success of sustainable development in Africa lies in addressing the imminent energy crisis in the continent. Excessive usage of fuel wood is already creating considerable environmental problems especially in the Sahel. Africa has all the potentials to solve its energy problems if appropriate infrastructural support can be provided for harnessing the abundant renewable resources in the continent, and if skills are pooled together and experiences shared in addressing the key issues.     

Experimental study of gasification of biomass residues for electrical energy generation

In the present work the gasification process of different types of biomass residues (cork residues) generated by industries in Spain has been studied. These sub products are classified as black agglomerates (low and high granulate). Samples of several residues obtained through different phases of the production process were collected, following a subsequent quantification of each of the four types obtained. First the sandpaper dust was tested, varying the air flow from 50 to 400 cm³ min^?1 and the temperature of the reaction from 650 to 800°C. A preliminary study of a pilot installation of gasification of 50 kWe using these residues was made taking into account the experimental results obtained in the laboratory. A thermal power of 220 kW was predicted for the installation, taking into account the energetic characteristics of the residues for 50 kg h^?1 of raw material, with installation efficiency of 22.5%. Copyright © 2011 John Wiley & Sons, Ltd.     

Analysis of biomass residues potential for electrical energy generation in Albania

This paper presents the status of research of biomass potential for producing electrical energy in Albania. Biomass potential can be generated by different sources. Three types of biomass energy sources are included: dedicated bioenergy crops, agricultural and forestry residues and waste. The technical electrical energy considered in this study was calculated with two converting techniques: (1) combustion of the feedstock directly in an incinerator and then driving a steam generator for producing electrical energy and (2) production of biogas from an anaerobic digester and running a turbine for electrical energy generation. Analysis of the potential biomass resource quantity was computed according to statistical reports, literature review and personal investigations. From the biomass residue potential was calculated in terms of the theoretical energy content (total heating value) of every type of feedstock and the technical energy content for every Albanian prefecture according to different burning processes and different operation efficiencies. Results show that Albania was producing around of 4.8 million tons of dry biomass in year 2005. The theoretical energy content of biomass in Albania was 11.6 million MWh/a, and the technical electrical energy production was 3 million MWh/a. The electrical energy produced is equivalent to 45.8% of total Albania Country annual electrical consumption. In Albania Country, residues from agriculture, forest and urban waste represent a large biomass potential. By actual conversion techniques it is possible to generate one third of the theoretical heat energy into technical electrical energy. The use of heat from cogeneration plants depends on local heat provision conditions. It is another big energy potential but excluded in this study, so the rest of energy is considered as heat losses.     

美国生物质能的发展状况及对我国的启示

2006年美国燃料乙醇产量为1 742万t,生物柴油产量90万t.2012年美国可再生燃料年利用量将增加到341亿L.美国发展生物质能主要目的是保护美国农民利益,通过政府引导,市场调节促进生物质能的产业发展;为了有效地规避风险,美国芝加哥期货交易所推出燃料乙醇期货.对我国的启示是,发展燃料乙醇不能照搬美国的模式,我国燃料乙醇要走多元化道路,政府要加大科研、开发的扶持力度,以及加强中美在生物质能领域的合作等.     

Political will and collaboration for electric power reform through renewable energy in Africa

Climate change, in particular rainfall variability, affects rain-dependent agriculture in Africa. The resulting food shortages, in combination with rising population and lack of access to electricity needed for development, require the governments and people of Africa to consider renewable energy sources. One example that has high potential in Africa is solar energy. Many African governments have begun discussions about renewable energy but tangible results have yet to materialize. This research contributes to the governmental efforts by presenting the solar electricity potentials for some African cities. Using photovoltaic geographical information system (PVGIS) data, it is clear that there is enough electricity for urban and rural dwellers if there is political will and if the solar panels are mounted at the suggested optimal angles ranging from 8–34°. The solar irradiation at all sites was higher than the typical daily domestic load requirement of 2324 Wh/m² in urban and rural areas. We provide a strong rationale for political will, collaboration and transparent energy policies that will ensure that life is enhanced through the use of environmentally-friendly renewable energy technologies such as solar power.     

Progress in the production of hydrogen energy from food waste: A bibliometric analysis

The exponential increase in food waste generation has prompted the scientific community to convert it into value-added resources. Hydrogen energy provides a sustainable option to fossil fuels due to its purity, high energy content, with no emissions other than water vapor. Combining the two aspects, a bibliometric analysis was performed for the conversion of food waste to hydrogen energy to evaluate the research trends based on literature in the Scopus database over the last two decades. The cluster analysis supported with the visualization tool aided in conducting a systematic study revealing growing themes and hot issues. The results showed a growing interest in the conversion of food waste to hydrogen energy research with the number of publications increasing by nearly 50 times in the last two decades. Comprehensive journals like the International Journal of Hydrogen Energy were most popular in publishing articles contributing to almost 30% in the research area. The country-wise analysis revealed that China accounted for more than 25% of the articles published followed by South Korea and India while the USA dominated in terms of the number of citations. Lastly, keyword cluster analysis revealed five major research hotspots for future discussion. The study concludes that further perspectives on fuel delivery, environmental impacts, and social acceptance could aid in positive developments in the biohydrogen energy industry.     

Renewable energy in South Africa: Potentials,barriers and options for support

The challenge of transforming entire economies is enormous; even more so if a country is as fossil fuel based and emission intensive as South Africa. However, in an increasingly carbon constrained world and already now facing climate change impacts South Africa has to reduce greenhouse gas emissions intensity soon and decidedly. The South African electricity sector is a vital part of the economy and at the same time contributes most to the emissions problem. First steps have been taken by the South African government to enhance energy efficiency and promote renewable energy, however, they fail to show large-scale effects. This paper seeks to identify the relevant barriers to renewable energy investments and, based on experience from other countries, provide policy recommendations.     

The economics of wind energy in South Africa

Battery charging and water pumping has been the only applications for wind energy in South Africa till now. A conservative estimate of the wind resource indicates that approximately 5% to 6% of the South African energy demands can be supplied from wind. However the low cost of electricity due to the abundance of cheap coal has made it difficult to justify the use of grid connected wind turbines. As with other countries where wind energy is now a part of the total energy package, South Africa will also have to go through a process of wind energy having to prove itself as a viable option while at the same time have a cost disadvantage.     

Harvesting operations and energetics of tall grasses for biomass energy production: A case study

The U.S.A. imports about 50% of its energy needs while Florida imports about 85%. Among the renewable energy sources available, biomass appears promising especially in the southeast which includes Florida because of a favorable environment for production and the available methods to convert biomass to energy. Optimal production of biomass requires the identification and management of high yielding persistent perennial cultivars. Elephantgrass (Pennisetum purpureum Schum.) and energycane (Saccharum spontaneum L.) are two tall grasses that meet these requirements. To optimize the supply of convertible biomass, suitable methods of harvesting the crop must be available. The purpose of this research was to study the feasibility and energetics of harvesting, drying, and baling tall grasses with conventional farm machinery.

A Mathews rotary scythe and a New Holland 849 Auto Wrap large round baler were determined to provide a practical harvesting system for baled biomass averaging 15–27 Mg ha⁻¹. The rotary scythe can be used for harvesting and fluffing or turning a windrow over to expedite drying. This harvesting system requires about 3 kg diesel fuel Mg⁻¹ dry biomass (DB), 25 min of time Mg⁻¹ DB, and a cost of about $10 to 12 Mg⁻¹ DB. Energy requirements of harvesting operations would be about 300–375 MJ Mg⁻¹ DB, and primary energy requirements for production and harvesting are about 1100–1500 MJ Mg⁻¹ DB. For each unit of fossil fuel invested in the total production and harvesting system, 12–15 units would be returned in biomass.