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1.
Rural Energy     
One of the most critical problems facing many developing countries is that of the alarming rate of depletion of traditional sources of energy, largely fuelwood and charcoal, which together command the largest share of energy used in rural areas. This has resulted in soil erosion, degradation of the land, reduced agricultural productivity and potentially serious ecological change. The social and economic impacts have been detrimental to the countries' populations, particularly for those living in the rural areas. Urgent action is therefore required to correct the fast deteriorating situation through evolution of fitting policies, establishment or strengthening of appropriate institutions and provision of adequate funding. But resolving the situation will be difficult and challenging for the problems are many, some of them complex. New sources of energy such as solar, wind, biomass, hydro and geothermal have a potential role to play in helping meet current and future energy requirements in the rural areas; but their widespread use and acceptance would be enhanced through increased research, development and demonstration, more funding, improved education and training and better flow of information on the advances in these fields.  相似文献   

2.
The past few years have seen a phenomenal rise in the production and consumption of biofuels and biodiesel at the global level. This development is of special significance to Africa, where about 550 million people (75% of the total population in Sub‐Saharan Africa) depend on traditional biomass (wood, charcoal, cow dung, etc.) and lack access to electricity or any kind of modern energy service. Derived from plants and agricultural crops, biofuels and biodiesel represent modern forms of bioenergy and more efficient use of biomass energy. Beyond efficiency, modern bioenergy offers tremendous opportunities to meet growing household energy demands, increase income, reduce poverty, and mitigate environmental degradation. In the African setting, energy and livelihoods security are indeed inseparable. This paper argues economic, social, and environmental benefits of modern bioenergy can be realized through a strategy that centres on smallholder production and processing schemes and pursuit of a livelihood approach to energy development. Such a scheme opens up new domestic markets, generates new cash incomes, improves social wellbeing, enhances new technology adoption, and lays the ground for rural economic transformation and sustainable land use. The paper concludes by underlining the vital importance of considering sound property rights and strategic planning of sustainable development as tools for sustainable energy and livelihoods security.  相似文献   

3.
简述了生物质概念及生物质利用技术的概况,介绍了生物质(竹、木剩余物)气、炭、液、油四联产生物质能源利用产业链的发展思路,对生物质利用的市场应用及发展进行了分析预测。  相似文献   

4.
The substitution of coal for charcoal in domestic use in Dakar and Dar es Salaam is not immediately feasible for technical, social and economic reasons. In the event of severe charcoal shortages, coal is the only large-scale substitute likely to be available and research should be carried out to ensure that the problems of its use and distribution are solved in advance. Coal, bottled gas, improvements in stove efficiency and charcoal manufacture are unlikely to ease the pressure on free-good wood resources unless they are associated with effective ceilings on wood exploitation. The production of charcoal for urban use should become a commercial responsibility linked with rural wood lot planting and exploitation. La substitution du charbon à la place du charbon de bois pour les usages domestiques à Dakar et à Dar es Salaam n'est pas possible dans l'immédiat pour des raisons techniques, sociales et économiques. Dans le cas de pénuries aigues en charbon de bois, le charbon est l'unique combustible de remplacement qui serait disponible sur une grande échelle et des recherches devraient être entreprises afin de s'assurer que les problèmes concernant son utilisation et sa répartition soient résolus d'avance. Le charbon, le gaz en bouteille, les améliorations dans le rendement des fourneaux et dans la fabrication du charbon de bois ne soulageront sans doute pas la pression exercée sur les ressources gratuites en bois à moins que celles-ci ne soient limitées par des plafonds concernant l'exploitation du bois. La production du charbon de bois pour les utilisations urbaines devrait être commercialement liée à un programme de plantation et d'exploitation parcellaires rurales. La substitución de carbón vegetal por carbón mineral para uso doméstico en Dakar y Dar es Salaam no es factible en forma immediata debido a razones técnicas, sociales y económicas. En caso de una escasez severa de carbón vegetal el único substituto que puede estar disponsible es el carbón mineral; en consecuencia debe investigarse para asegurar que los problemas de su uso y distribución sean resueltos con anticipación. El carbón mineral, el gas embotellado, y las mejoras en la eficiencia de las cocinas y en la fabricación del carbón vegetal tienen poca probabilidad de disminuir la demanda de un bien gratuito como es la leña a menos que esten asociados a una limitación efectiva de la explotación de los bosques. La producción del carbón vegetal para uso urbano debe ser una responsabilidad comercial ligada a la reforestación y explotación de bosques.  相似文献   

5.
In this paper, the energy and environmental dimensions of several proposed energy strategies for Senegal are explored. An analytical framework to compare the energy and measurable environmental impacts of a set of scenarios is developed, and the limitations of the quantitative approach are discussed. It is found that policies to promote substitution of liquid petroleum gas (LPG) for charcoal use in households may actually reduce greenhouse gas emissions, while also improving more important near-term environmental problems. Substitution of LPG for charcoal would not necessarily lead to a significant increase in Senegal's oil import bill, since other petroleum product usage will continue to dominate. Despite past industrial sector initiatives, considerable potential for energy efficiency investment remains, and presents additional opportunities for minimizing environmental impacts.  相似文献   

6.
Woodfuels (firewood and charcoal) comprise the predominant source of energy for rural populations in developing countries, and are likely to continue to do so. Increasing depletion of locally available wood supplies can lead to reductions in energy available for cooking and heating, increasing diversion of agricultural residues to fuel use, and deterioration of physical environments dependent on tree cover. This paper examines different ways of dealing with the problem and argues that attention must be paid to means of alleviating demand for woodfuels in the short term by using existing supplies more efficiently, as well as to increasing their supply over the longer term.  相似文献   

7.
A Review of Range Production and Management Extension Activities in Kenya   总被引:1,自引:0,他引:1  
The paper presents an overview of the development of range management extension activities in Kenya. The status quo of range management activities is discussed with particular reference to extension infrastructure, scope of extension interventions and mechanisms of dissemination of these innovations. On the basis of the nature of available innovations and efficiency of dissemination mechanisms, the paper emphasizes the need for future institutional reforms to facilitate successful application of technological interventions, validation of the Kenyan innovation Diffusion Model and enhancement of the social acceptability of technological interventions. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   

8.
Biotic pressure in and around protected areas (PA) is the primary cause of biodiversity loss in many developing countries across the globe. The pressure comes partly from biomass energy dependency in the form of heavy extraction of fuelwood from the forests. Although biomass fuels provide easily accessible and affordable sources of domestic energy to the rural masses, their combustion results in environmental and health‐related hazards. The objectives of this paper are to assess the patterns of household energy use in a subsistence forest economy and analyze the factors that influence their energy use choice for cooking and lighting. The paper uses primary data collected randomly from 244 households located in and around the Similipal Tiger Reserve (STR), situated in the eastern Indian state of Odisha. Age of the household head, number of days in wage employment, number of adult males and females in a household, education of the household head and landholding size are found to be the major variables that determine household fuelwood collection sources inside the reserve. Considering household structure as an income indicator, the analysis clearly shows that non‐poor households prefer to use clean energy (i.e. solar) for lighting, while poor households tend to use solid fuel. Energy policies for development should be based on the realistic proposition that fuelwood will remain the major source of energy for cooking for substantial proportions of the world’s population. Promotion of public education, social forestry schemes and fuel‐efficient improved chulhas should be encouraged in order to reduce household dependence on fuelwood. Moreover, devolving sufficient property rights over forest resources to local communities may help secure their broad‐based and active participation in the decision‐making process, which may result in a positive change in the attitude of the local people towards biodiversity conservation.  相似文献   

9.
A steady-state space radiant heat model and a stove combustion model are developed to simulate the heat exchanges between various surfaces in the room and the stove and stack surfaces, assuming stiochiometric combustion inside the stove and the exhaust gases flow out through the stack by natural convection. The space heat model calculates the fuel consumption, the stove, stack temperatures, and the mass flow rate of exhaust gases, and provides an opportunity to study the energy efficiency of the stove, while satisfying the constraints of thermal comfort. Fanger (1982) Fanger, P. O. 1982. Thermal Comfort Analysis and Applications in Engineering, 156198. New York: McGraw Hill.  [Google Scholar] model and a radiation exchange model between various surfaces of the space, the thermal building energy balance, and stove combustion process is applied to determine the mean radiant temperature (MRT) and the extent of thermal comfort as determined by predicted mean vote (PMV).

The overall model is validated by performing experiments in a room placed inside a controlled outdoor environment. The room is heated using a domestic stove common for rural areas of Lebanon and the MRT, the room air temperature, the walls and window temperatures are measured at two stove positions. The measured MRT, the average room temperature, and the wall surface temperatures agreed within ±7% of values predicted by the numerical model.

A parametric study is performed to optimize the stove and occupant locations in the room where adequate comfort level can be maintained at lower fuel consumption levels. The values of MRT and PMV depend strongly on the position of the radiant stove heater and stack with respect to the cold window and the occupant location. It is shown that it is possible to save up to 15% in stove fuel consumption by changing the stove position in the room with respect to the window and to the person, while maintaining the same level of comfort.  相似文献   

10.
This article examines the utilization characteristics and importance of woody biomass resources in the rural-urban fringe zones of Botswana. In the literature for Africa, attention has been given to the availability and utilization of biomass in either urban or rural environments, but the rural-urban fringe has been neglected. Within southern Africa, this neglect is not justified; the rural-urban fringe, not getting the full benefits available in urban environments in Botswana, has developed problems in woody biomass availability and utilization that require close attention. In this article, socioeconomic data on the importance of woody biomass in the Batlokwa Tribal Territory, on the rural-urban fringe of Gaborone, Botswana, were collected together with ecologic data that reveal the utilization characteristics and potential for regrowth of woody biomass. The analysis of these results show that local woody biomass is very important in the daily lives of communities in the rural-urban fringe zones and that there is a high level of harvesting. However, there is no effort in planning land use in the tribal territory to either conserve this resource or provide alternatives to its utilization. The future of woody biomass resources in Botswana’s rural-urban fringe is uncertain. The investigators recommend that a comprehensive policy for the development of the rural-urban fringe consider the importance of this resource. The neglect of this resource will have far-reaching implications on the livelihoods of residents as well as the environment in this zone.  相似文献   

11.
Fuelwood is the primary energy source for domestic purposes throughout the developing world, in both urban and rural environments. Due to the detrimental impacts of biomass use on human and environmental health, many governments have sought to reduce its use through provision of potentially cleaner energies, of which electricity is the dominant form. Yet there are surprisingly few studies of changes in fuelwood use following the introduction of electricity, especially in rural areas of Africa. This paper reports on a longitudinal study of fuelwood use, using identical approaches, in five rural villages in the Bushbuckridge region of South Africa, spanning the period over which electricity became widely available. Almost a decade after the introduction of electricity, over 90% of households still used fuelwood for thermal purposes, especially cooking, and the mean household consumption rates over the 11-year period had not changed, even with a policy of 6 kWh per month of free electricity. The proportion of households purchasing fuelwood had increased, probably in response to a number of factors, including (i) increased fuelwood scarcity in the local environment as reflected by increased fuelwood collection times, changes in fuelwood species preferences, and ranking of scarcity by local collectors, and (ii) increases in the price of fuelwood well below that of other fuels and the prevailing inflation rate. Overall, there was an increase in the number of species harvested over the 11-year period. The implications of these findings for rural energy provision are discussed.  相似文献   

12.
生物质的破碎是生物质能源利用转化的前提条件。本文介绍了一种用于生物质精细破碎的成套系统,简述了其中粗破碎机、精破碎机的结构特点和工作原理,并对生物质破碎的原料和破碎产物以及系统的生产效率和生产成本进行了分析。  相似文献   

13.
In this paper the function of protected nature in rural living environments is discussed in relation to residential choice, appreciation of the residential environment and rural development policy. In five case studies a comparison is made between the situation of protected natural areas in the Netherlands, England and Spain. The research results show that protected natural areas are an increasingly popular endogenous quality of rural regions as they have the ability to influence the residential choice and satisfaction of households. Therefore, they have not only become an important driving factor in the attraction of residential and other consumption-orientated activities towards rural areas but also need to be considered in policy formulation. After all, choices have to be made when different functions need to be combined in rural areas. Different activities may have both positive and negative effects on each other and regulatory measures are needed to tune their co-existence. For a sustainable and balanced development of rural areas it is therefore very important to create basic conditions that will make the combination of activities possible within the specific national and regional contexts.  相似文献   

14.
Rural landscapes are highly dynamic and their change impacts on a number of ecological processes such as the dynamics of biodiversity. Although a substantial amount of research has focused on quantifying these changes and their impact on biodiversity, most studies have focused on single dimensions of land use change. This lack of integration in land use change studies can be explained by the fact that data on the spatial, temporal, and ecological dimensions of land use are seldom available for the same geographical location. In this paper, the benefits of taking into account these three dimensions are illustrated with results derived from the Great Britain Countryside Surveys (CS), a large-scale monitoring programme designed to assess change in the extent and ecological condition of British habitats. The overview of CS results presented in this paper shows that (1) changes in land use composition will translate into a variety of spatial patterns; (2) the temporal stability of land use is often lower than can be expected; and (3) there can be large-scale shifts in the ecological condition of the land use types that form our rural landscapes. The benefits of integrated rural landscape studies are discussed in the context of other national monitoring programmes.  相似文献   

15.
Land abandonment is an important cause of changes in landscape patterns in the Mediterranean area. There is a need to monitor land use and land cover changes in order to provide quantitative evidence of the relationship between land abandonment and the formation of new landscape patterns. Appropriate management policies to encourage sustainable development can then be developed. This paper describes how to monitor landscape dynamics using different temporal land use and land cover data generated from field survey and airborne information. The results showed that the abandonment of agricultural land generally results in an increase of vegetation biomass. This process leads to homogenization of the landscape. In addition, abandonment promotes fragmentation of agricultural land. Based on these results, the paper discusses the implications for rural management policies concerning the abandonment of agricultural land and suggests recommendations for the development of such policies.  相似文献   

16.
Forests and competing land uses in Kenya   总被引:1,自引:0,他引:1  
Indigenous forests in Kenya, as in other developing countries, are under heavy pressure from competing agricultural land uses and from unsustainable cutting. The problem in Kenya is compounded by high population growth rates and an agriculturally based economy, which, even with efforts to control birth rates and industrialize, will persist into the next century. Both ecological and economic consequences of these pressures need to be considered in land-use decision making for land and forest management to be effective. This paper presents one way to combine ecological and economic considerations. The status of principal forest areas in Kenya is summarized and competing land uses compared on the basis of ecological functions and economic analysis. Replacement uses do not match the ecological functions of forest, although established stands of tree crops (forest plantations, fuel wood, tea) can have roughly comparable effects on soil and water resources. Indigenous forests have high, although difficult to estimate, economic benefits from tourism and protection of downstream agricultural productivity. Economic returns from competing land uses range widely, with tea having the highest and fuel wood plantations having returns comparable to some annual crops and dairying. Consideration of ecological and economic factors together suggests some trade-offs for improving land allocation decisions and several management opportunities for increasing benefits or reducing costs from particular land uses. The evaluation also suggests a general strategy for forest land management in Kenya.The views and interpretations expressed in this article are those of the authors and should not be attributed to the World Bank, its affiliated organizations, or any individual acting on their behalf.  相似文献   

17.
Development Potentials and Policy Options of Biomass in China   总被引:7,自引:0,他引:7  
Biomass, one of the most important renewable energies, is playing and will continue to play an important role in the future energy structure of the world. This article aims to analyze the position and role, assess the resource availability, discuss the geographic distribution, market scale and industry development, and present the policy options of biomass in China. The resource availability and geographical distribution of biomass byproducts are assessed in terms of crop residues, manure, forest and wood biomass byproducts, municipal waste and wastewater. The position of biomass use for power generation is just next to hydropower among types of renewable energy in China. The potential quantity of all biomass byproducts energy in 2004 is 3511 Mtce (Mtce is the abbreviation of million tons of coal equivalents and 1 Mtce is equal to106 tce.), while the acquirable quantity is 460 Mtce. Biomass energy plays a critical role in rural regions of China. The geographical distribution and quantity of biomass byproducts resources depends mainly on the relationship between ecological zones and climate conditions. Our estimation shows that the total quantity of crop residues, manure, forest and wood biomass byproducts, municipal waste and wastewater resources are 728, 3926, 2175, 155 and 48240 Mt (million tons), respectively. Crop residues come mainly from the provinces of Henan, Shandong, Heilongjiang, Jilin and Sichuan. All manure is mainly located in the provinces of Henan, Shandong, Sichuan, Hebei and Hunan. Forest and wood biomass byproducts are mainly produced in the provinces or autonomous regions of Tibet, Sichuan, Yunnan, Heilongjiang and Inner Mongolia, while most of municipal waste mainly comes from Guangdong, Shandong, Heilongjiang, Hubei and Jiangsu. Most of wastewater is largely discharged from advanced provinces like Guangdong, Jiangsu, Zhejiang, Shandong and Henan. Biomass byproducts’ energy distribution also varies from province to province in China. Based on the analysis of the market scale and industry development, the article argues that China’s biomass energy industry is still at a very early stage of development and that Feed-in Tariffs (FIT) might be the best policy option for China to promote its development of biomass energy. A successful enforcement of FIT in China needs some policy combination of special capital subsidies, R&D funding, tax incentives and pricing.  相似文献   

18.
The anaerobic digestion of industrial wastes produces a biogas that is an alternative to the use of fossil fuels for energy production. At the end of this process, the stabilized biomass presents high levels of nutrients, which can be used both as biofertilizers in agriculture and for the biodegradation of contaminants in the soil through improvement of the microbiota. Thus, this study aimed to evaluate biogas production by industrial wastes and to use the biofertilizer for the bioremediation of soils previously contaminated with gasoline. The biomass (420 mL) generated approximately 10 liters (L) of methane and 3 L of other gases. Anaerobic incubation reduced total and volatile solids, as well as biochemical oxygen demand, chemical oxygen demand, and the carbon and nitrogen contents of the biomass. The bioremediation experiment showed that 15 days after contamination with gasoline, the addition of the biofertilizer improved the degradation efficiency of monoaromatic hydrocarbons; however, the degradation of polyaromatic hydrocarbons was less time efficient. So, we conclude that the anaerobic incubation of industrial wastes generates a high amount of biogas, and that biofertilizer deposition into contaminated soil does not affect the efficiency of the degradation of aromatic hydrocarbons after 30 days. Novelty or significance : Anaerobic incubation of industrial wastes generates a high calorific value gas, which can be used as an alternative source of energy. And, the resulting biomass, called biofertilizer, can be used to remediate soils contaminated with hydrocarbons.  相似文献   

19.
Air quality in the UK, although vastly improved from the smogs of the 1950s, now faces a new set of challenges from a variety of sources and pollutants. Poor air quality has long been associated with urban areas, but it is becoming clear that many rural locations also have locations likely to exceed the UK Air Quality Strategy-objectives: This paper will examine the extent to which rural authorities have been engaged in the local air-quality management (LAQM) process, a new regime by which air quality control is being accomplished in the UK. Results are presented from a questionnaire survey of environmental health officers of 100 rural authorities undertaken in January 1999. The paper investigates both the technical aspects of the LAQM process as well as the management approaches. The current progress of rural authorities, and some of the problems they face, are discussed particularly in comparison with urban areas. It is concluded that some rural authorities with air pollution problems stemming either from within or outwith their borough, may face significant challenges from the LAQM review and assessment process, particularly where air pollution responsibilities have only relatively recently been addressed. Rural authorities seem to be embracing these new responsibilities enthusiastically, but it is almost inevitable that they will be trailing behind urban authorities who have several decades of experience and joint working to draw upon.  相似文献   

20.
The pulp and paper industry is energy intensive and consumes large amounts of wood. Biomass is a limited resource and its efficient use is therefore important. In this study, the total amount of biomass used for pulp and for energy is estimated for the production of several woodfree (containing only chemical pulp) and mechanical (containing mechanical pulp) printing paper products, under Swedish conditions. Chemical pulp mills today are largely self-sufficient in energy while mechanical pulp mills depend on large amounts of external electricity. Technically, all energy used in pulp- and papermaking can be biomass based. Here, we assume that all energy used, including external electricity and motor fuels, is based on forest biomass. The whole cradle-to-gate chain is included in the analyses. The results indicate that the total amount of biomass required per tonne paper is slightly lower for woodfree than for mechanical paper. For the biomass use per paper area, the paper grammage is decisive. If the grammage can be lowered by increasing the proportion of mechanical pulp, this may lower the biomass use per paper area, despite the higher biomass use per unit mass in mechanical paper. In the production of woodfree paper, energy recovery from residues in the mill accounts for most of the biomass use, while external electricity production accounts for the largest part for mechanical paper. Motor fuel production accounts for 5–7% of the biomass use. The biomass contained in the final paper product is 21–42% of the total biomass use, indicating that waste paper recovery is important. The biomass use was found to be about 15–17% lower for modelled, modern mills compared with mills representative of today's average technology.  相似文献   

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