Suchergebnisse

As crop straw and firewood are generated as by-products of food production systems, they are perceived to be sustainable energy sources that do not threaten food security by Chinese government for a long time. However, the time spent on collecting straw and firewood may create a burden on rural household, as it could reduce the available labor inputs for agricultural production, which in turn, possibly brings negative impact on food security. Building on an integrated agriculture-energy production system, a Symmetric Normalized Quadratic (SNQ) multi-output profit function (which includes labor allocations as quasi-fixed factors) is estimated to investigate the impacts of traditional biomass energy use on agricultural production in this paper. The negative signs of the calculated cross-price elasticities of supply (agricultural products and biomass energy) confirm that the relationship between biomass collection and agricultural production is competition. Moreover, the cross-price elasticities of biomass collection with respect to inputs are positive, implying that indirect link between biomass collection and agricultural production perhaps lies in household consumption decisions. The important implication of this study is that potential policy interventions for developing biomass energy in rural China could aim at enhancing food security by improving household motivation of engaging in agricultural production and slowing down the competition between biomass collection and agricultural production. It is suggested that government should attach more importance to simultaneously promote the prices of agricultural products and control the prices of intermediate inputs.

Introduction -- Analytical framework -- Household biomass energy choice for cooking in energy transition and its impacts on rural livelihoods -- Evaluating the impacts of biomass collection on agricultural production -- Impacts of the changes in exogenous markets on household biomass energy use -- Conclusions and policy implications -- References -- Appendix

Energy is an area of strategic and vital importance for Romania's economic development. At national level there is a wide activity of using biomass for the production of electricity and heat, determined by the requirements of the European Union's energy policy to reduce CO2 emissions. The availability of biomass resources has made it an attractive source of renewable energy, with the potential to provide economical and cost-effective energy. The paper presents a review of directions and policies on bioenergy and energy production through the use of biomass.

Biomass feedstocks for biopower: background and selected issues / Kelsi Bracmort -- Biomass crop assistance program (BCAP): status and issues / Megan Stubbs -- Biomass crop assistance program (BCAP): fact sheet / U.S. Department of Agriculture -- Biomass: comparison of definitions in legislation through the 111th Congress / Kelsi Bracmort, Ross W. Gorte -- Biomass resources: the southeastern United States and the renewable electricity standard debate / Richard J. Campbell -- Overview of biomass technologies -- Cellulosic biofuels: analysis of policy issues for Congress / Kelsi Bracmort ... [et al.]

Biomass, a broad term for all organic matter of plants, trees and crops, is currently regarded as a renewable energy source which can contribute substantially to the world's energy supply in the future. Various scenarios for the development of energy supply and demand, such as compiled by the World Energy Council (WEC), the Intergovernmental Panel on Climate Change (IPCC), Shell and the Stockholm Environmental Institute (SEI), indicate that biomass has the potential to make a large contribution to the world's energy supply. Estimates of this potential in the year 2050 vary from 14% to 50% of the total supply, or from 100 to about 300 EJ/yr. It is estimated that currently biomass contributes 10-14% of the energy supply, which is equivalent to about 40-55 EJ/yr. The use of firewood in developing countries makes up a large part of this 40-55 EJ, but there it is for a large part non-commercial and non-sustainable use of biomass. In recent years there has been renewed interest in biomass as a commercial and sustainable source of energy. There are three main reasons for this: 1. Technological developments, in the field of crop production and conversion technology permit the more efficient and cleaner utilisation of biomass at lower costs. These developments make bioenergy more competitive with energy produced from fossil fuels. 2. The agricultural systems of especially the European Union and the United States are producing food surpluses. This situation has led to policies whereby agricultural land is 'set-aside', resulting in depopulation of rural areas. The continuously increasing productivity in agriculture might strengthen these trends. There is therefore a desire to develop alternative crops. Energy crops could be a suitable alternative since there is virtually an infinite market for this, provided the costs are competitive with those of fossil fuels. 3. There is a threat of global climate change due to the rapid increase in the concentration of greenhouse gases, especially CO2 in the atmosphere, resulting mainly from the large scale use of fossil fuels. If produced sustainably, biomass can be a carbon neutral alternative for fossil energy carriers. If biomass is to make a substantial contribution to the world's energy supply it will have to include not only biomass residues - such as from commercial forestry (e.g. thinnings) and agriculture (e.g. straw) - and organic wastes, but also energy crops. Perennial crops seem to be a particularly promising energy source. Crops like Short Rotation Coppice (e.g. Willow and Eucalyptus) and grasses (e.g. Miscanthus) give a relatively high net energy yield per hectare, have a low environmental impact and produce relatively cheap energy. The use of such crops in a Biomass Integrated Gasifier/Combined Cycle (BIG/CC) plant to produce electricity or combined heat and power, and the gasification of these crops to produce fuels like methanol and hydrogen appear to be promising routes for achieving high energy conversion efficiency at relatively low cost. However, despite the promising outlook, various barriers are hampering the large scale development and implementation of commercial biomass energy systems. Currently, the commercial use of biomass to generate electricity is limited mainly to the utilization of zero- or low-cost biomass waste or residues. At the moment specially cultivated biomass is too expensive an option. However, biomass is able to compete on a significant scale in countries, like Sweden, Denmark and Brazil, where government policies support its use financially or have actively discouraged the use of fossil fuels (such as by the introduction of a carbon tax). The complexity of large scale bioenergy systems is also a barrier. Furthermore, biomass has a relatively low energy density. The production of biomass is bound up with seasons and makes high demands on organization and logistics. Furthermore, it involves many different actors involved in the production and utilisation of energy crops: farmers, utilities, industries, governments, etc. Difficulties concerning public acceptability and uncertainties concerning the ecological effects of the large scale production of use of biomass be form another problem. Last but not least, the availability of land may be a major problem if the large scale production of energy crops is being considered. If agriculture is not modernizing, especially in developing countries, there might be very little room left for alternative crops. Energy farming may then conflict with food production, a situation which is highly undesirable. This thesis focuses on a number of aspects relating to the utilization of biomass and waste for energy purposes. The general objective of this work is as follows: "To analyse the possibilities for biomass (both crops and wastes) as a modern energy carrier in the Dutch energy system." Therefore this thesis has the following specific objectives: 1. To analyze of the technical, economic and environmental characteristics of Biomass Integrated Gasifier/Combined Cycle technology for the conversion of biomass and waste streams. 2. To examine the potential energy supply of energy farming, biomass residues, organic waste streams and waste in the Netherlands. 3. To analyze of the potential costs and benefits of different biomass energy systems (including waste treatment) in the Netherlands.

Recently, the use of biomass energy has been growing worldwide on an accelerated trajectory, with the prospect of staying among the main renewable energy sources for the coming decades, along with wind and solar energy. Brazil is the largest producer of sugarcane on the planet and the second-largest producer of ethanol. But in addition to sugar, first-generation ethanol, and vinasse (for ferti-irrigation), other by-products and process residues from the plants (such as bagasse, filter cake, vinasse, straw, and sugarcane tip) can be used for the production of thermal and electric energies and also second-generation ethanol and biogas fuels. In this context, this paper presents the current scenario of sugarcane biomass in Brazil, discussing issues involving the use of sugar-alcohol by-products for bioenergy and biofuel production. Furthermore, a study on the reuse of sugarcane bagasse fibers for the production of eco-composite material is also presented. Finally, the concepts of biomass energy are described from a bibliographic survey and the previous experiences of the authors.