中国农村生物质能消费的CO_2排放量估算

借助国际通用的CO2排放鼍计算方法,利用1996～2006年中国农村可再生能源统计资料,对中同农村生物质能消费的CO2排放情况及其空间分布进行分析探讨.结果表明,中国农村生物质能消费的CO2排放总量达到7.25×108t,约占农村生活能源消费CO22排放量的65%,占全国温窜气体总排放量的11.2%,其中秸秆、薪柴等传统生物质能利用方式贡献较大,可达98.64%～99.74%;中国农村生物质能消费CO2排放量的空间分布不均,四川、广西等省CO2排放量大,属超重排放区域,北京、天津、上海、西藏、青海等省(市、区)排放量小,属轻排放区域:区域生物质资源条件和经济社会水平是影响农村生物质能消费CO22排放的主要因素.     

中国农村能源温室气体主要减排技术评价及潜力分析

农村能源减排技术是优化能源结构,减少温室气体排放的重要途径之一,有利于实现国家温室气体减排的目标。文章综合分析评价了农村能源温室气体减排技术,计算减排效果并估算未来的减排潜力。结果表明,2009年中国主要农村能源技术温室气体减排量为8 529万tCO2,测算到2020年,中国农村能源温室气体的减排潜力约为2.97亿t CO2。农村户用沼气、生物质固体成型燃料、太阳能热利用等农村节能减排技术已基本成熟,实现了产业化应用,且减排潜力较大,是未来推广的重点。     

生物质气化对减少CO_2排放的作用

分析了生物质利用过程中几种能量利用系统的特点及整体效率 ,论述了生物质和矿物燃料在 CO2 排放方面的不同特点 ,分别得出产生单位有效能源时 CO2 的排放值。通过比较发现 ,高效的生物质利用技术相对于矿物燃料 ,可以减少 CO2 排放 90 %左右。这充分证明利用生物质替代矿物燃料是减少 CO2 排放的有效措施之一 ,而气化技术是高效利用生物质的重要途径。     

中国农村生活用能及其碳排放分析(2001-2010)

分析了2001~2008年中国农村生活用能的变化以及2001~2010年中国农村生活用能对气候变化的影响。研究发现,农村生活用能呈现了从非商品能源向商品能源转变的趋势,其中,传统生物质能源的消费比例从81.5%下降至70.9%,而商品能源则从17.1%上升至25.1%。此外,除传统生物质能源外的其它可再生能源的消费增长迅速,年均增长率为19.8%。与此相应,农村生活用能消费所导致的碳排放呈现出显著的增加趋势,由152.2百万t上升至366.89百万t,且农村人均CO2排放的增长速度是同期城镇人口的1.87倍。分析认为,影响商品能源消费的主要因素是农村居民收入的增加,强有力的政策支持则促进了农村除传统生物质能源外其他可再生能源的发展。     

福建省能源活动温室气体排放测算及其碳强度趋势

根据《省级温室气体清单编制指南(试行)》,福建省能源活动温室气体包括化石燃料、生物质燃料燃烧活动产生的CO2、CH4和N2O排放及煤矿和矿后活动、石油和天然气系统产生的CH4逃逸排放。界定福建省能源活动过程温室气体的排放源及温室气体种类;给出各排放源相关的温室气体排放量估算方法,确定活动水平数据及排放因子,并估算各排放源温室气体的排放量;汇总化石燃烧排放的CO2量,化石燃料燃烧、生物质燃料燃烧、煤炭开采和矿后活动逃逸、石油和天然气系统逃逸排放的CH4量,化石燃料燃烧和生物质燃料燃烧排放的N2O量;生成福建省能源活动温室气体清单汇总,并根据福建省地区生产总值GDP得出碳强度趋势。     

广东省低碳发展的能源消耗与CO2排放分析

作为中国经济大省、人口大省和能源消费大省,广东省先行启动国家低碳省试点工作,率先开展碳交易市场建设试点。能源消费特征和CO2排放情况是低碳发展的基础,从广东省经济发展入手,分析了广东省终端能源消费及构成、单位GDP能耗和单位工业增加值能耗等能源消费特征,估算了广东省2005年至2010年的CO2排放量,并预测了广东省“十二五”期间的能源消费和CO2排放量,为节能减碳和国家低碳试点工作提供基础数据和决策依据。     

中国减排CO2的初步分析

我国的一次能源以煤炭为主,所以必须实施煤炭现代化利用的能源发展策略,逐步替代现有以直接燃烧为主的能源利用系统。本为结合最新数据对中国的CO2排放源进行初步分析,对我国各行业煤炭消费和CO2排放构成进行预测,指出发电行业是我国推动CO2减排的重点,对我国CO2减排路线图提出了设想。     

中国住宅中能源消耗的CO2排放量及减排对策

利用生命周期评价方法,根据中国煤电链和水电链的温室气体排放系数,计算了各种燃料的温室气体排放系数,并在此基础上,计算出了1999年我国住宅中由于家用电器的使用、冬季集中供暖及农村生活能源消费所造成的温室气体排放量.通过数据分析得出住宅中主要能源消耗所产生的CO2排放量约占全国总排放量的34.34%.分析计算了一栋被动式太阳能建筑的减排潜力,提出了住宅中CO2减排的对策.     

我国化石能源燃烧产生的CO2排放量预测

基于我国化石能源消费的原始数据,应用灰色新陈代谢模型分别预测了2007~2020年煤、石油、天然气消费量,建立了化石能源消费量与CO2排放量的线性回归模型,实现了对化石能源燃烧产生的CO2排放量的预测,并分析了未来10 a化石能源消费与CO2排放趋势。结果表明,该方法计算简便、易操作、拟合度和预测精度较高、结果可靠,可为能源发展和CO2减排提供科学依据。     

生物质能的利用及生物质型煤

生物质能是可再生能源。生物质型煤可以有效降低CO2排放量和提高脱硫率。利用生物质的代煤作用及其燃烧特性，可以有效提高型煤的技术经济性能。     

中国居民生活与CO_2排放关系研究

本文采用Consumer Lifestyle Approach(CLA)方法,比较分析中国各地区和不同收入水平下居民的二氧化碳排放量。结果表明,城镇居民直接二氧化碳排放一直处于增长状态,农村增速较缓慢。城镇居民间接二氧化碳排放量高于直接消费。城镇居民食品、衣着、居住、教育文化是主要的二氧化碳排放源,农村居民食品消费占据主要比例。地区间的差异对于居民间接二氧化碳排放影响主要体现在总量上,收入水平对居民生活方式的间接二氧化碳排放量影响大,高收入水平的居民二氧化碳排放量高于低收入水平居民;收入水平越高,二氧化碳排放结构越多样化。根据研究提出了降低生活能源强度和二氧化碳排放强度的建议。     

Economics of herbaceous bioenergy crops for electricity generation: Implications for greenhouse gas mitigation

This paper examines the optimal land allocation for two perennial crops, switchgrass and miscanthus that can be co-fired with coal for electricity generation. Detailed spatial data at county level is used to determine the costs of producing and transporting biomass to power plants in Illinois over a 15-year period. A supply curve for bioenergy is generated at various levels of bioenergy subsidies and the implications of production for farm income and greenhouse gas (GHG) emissions are analyzed. GHG emissions are estimated using lifecycle analysis and include the soil carbon sequestered by perennial grasses and the carbon emissions displaced by these grasses due to both conversion of land from row crops and co-firing the grasses with coal. We find that the conversion of less than 2% of the cropland to bioenergy crops could produce 5.5% of the electricity generated by coal-fired power plants in Illinois and reduce carbon emissions by 11% over the 15-year period. However, the cost of energy from biomass in Illinois is more than twice as high as that of coal. Costly government subsidies for bioenergy or mandates in the form of Renewable Portfolio Standards would be needed to induce the production and use of bioenergy for electricity generation. Alternatively, a modest price for GHG emissions under a cap-and-trade policy could make bioenergy competitive with coal without imposing a fiscal burden on the government.     

Bioenergy villages in Germany: Bringing a low carbon energy supply for rural areas into practice

An increasing number of rural municipalities wants to meet their entire energy demand with biomass. This article gives a system analytic view on these “bioenergy villages” by balancing pros (reduction of CO₂ emissions) and cons (increasing costs, land use) using the example of a model municipality in Germany. The results indicate that a 100% energy supply based on biomass from within the boundaries of a rural municipality is technically possible but less reasonable with respect to land use competition and costs of energy supply. Whereas heat and power demand in bioenergy villages can be covered with relatively little land use and to relatively low costs, the production of transport fuel based on energy crops (rape seed) leads to significant negative impacts. For a cost-efficient decarbonization of rural areas it can therefore be recommended to particularly expand the utilization of biomass for heat and power production and to reconsider the transport fuel production.     

低碳发展下的大气污染物和CO2排放情景分析-上海案例研究

我国国民经济正在呈现快速增长态势，由于能源技术相对落后，能源加工及利用效率相对较低，使得我国能源供应面临巨大压力。为探索低碳发展对能源环境的影响，以上海为例，利用LEAP模型对“零方案”情景(BAU)和低碳发展情景下的能源消费及大气污染物排放量进行了预测。研究结果表明，实施低碳发展不仅可有效缓解能源供应压力，明显遏止本地大气污染物排放，改善环境空气质量，而且可减缓CO2排放增长速度。上海案例研究结果显示，低碳发展与末端治理相结合，2020年上海市的能源消费总量将比基础情景减少18％，常规大气污染物和碳排放状况也得到改善，CO2、SO2和PM的排放总量分别比基础情景下2020年的排放量减少了20％、72％和78％。低碳发展对我国中长期能源环境建设具有显著的多重正效应。     

On sustainability of bioenergy production: Integrating co-emissions from agricultural intensification

Biomass from cellulosic bioenergy crops is seen as a substantial part of future energy systems, especially if climate policy aims at stabilizing CO₂ concentration at low levels. However, among other concerns of sustainability, the large-scale use of bioenergy is controversial because it is hypothesized to increase the competition for land and therefore raise N₂O emissions from agricultural soils due to intensification. We apply a global land-use model that is suited to assess agricultural non-CO₂ GHG emissions. First, we describe how fertilization of cellulosic bioenergy crops and associated N₂O emissions are implemented in the land-use model and how future bioenergy demand is derived by an energy-economy-climate model. We then assess regional N₂O emissions from the soil due to large-scale bioenergy application, the expansion of cropland and the importance of technological change for dedicated bioenergy crops. Finally, we compare simulated N₂O emissions from the agricultural sector with CO₂ emissions from the energy sector to investigate the real contribution of bioenergy for low stabilization scenarios.As a result, we find that N₂O emissions due to energy crop production are a minor factor. Nevertheless, these co-emissions can be significant for the option of removing CO₂ from the atmosphere (by combining bioenergy use with carbon capture and storage (CCS) options) possibly needed at the end of the century for climate mitigation. Furthermore, our assessment shows that bioenergy crops will occupy large shares of available cropland and will require high rates of technological change at additional costs.     

How certain are greenhouse gas reductions from bioenergy? Life cycle assessment and uncertainty analysis of wood pellet-to-electricity supply chains from forest residues

Climate change and energy policies often encourage bioenergy as a sustainable greenhouse gas (GHG) reduction option. Recent research has raised concerns about the climate change impacts of bioenergy as heterogeneous pathways of producing and converting biomass, indirect impacts, uncertainties within the bioenergy supply chains and evaluation methods generate large variation in emission profiles. This research examines the combustion of wood pellets from forest residues to generate electricity and considers uncertainties related to GHG emissions arising at different points within the supply chain. Different supply chain pathways were investigated by using life cycle assessment (LCA) to analyse the emissions and sensitivity analysis was used to identify the most significant factors influencing the overall GHG balance. The calculations showed in the best case results in GHG reductions of 83% compared to coal-fired electricity generation. When parameters such as different drying fuels, storage emission, dry matter losses and feedstock market changes were included the bioenergy emission profiles showed strong variation with up to 73% higher GHG emissions compared to coal. The impact of methane emissions during storage has shown to be particularly significant regarding uncertainty and increases in emissions. Investigation and management of losses and emissions during storage is therefore key to ensuring significant GHG reductions from biomass.     

Carbon emissions by rural energy in China

Carbon emissions due to rural energy consumption in China have not yet been sufficiently addressed or quantified. In this work systematic accounting with a life cycle perspective was used to estimate both the direct CO₂ emissions from fuel combustion and the indirect emissions from the production and provision of rural energy carriers. The results indicate that the total direct CO₂ emissions resulting from rural energy consumption have nearly tripled, from 0.79 billion metric tons (hereafter ton) in 1979 to 1.98 billion tons in 2008, whilst indirect emissions have nearly quadrupled, from 0.27 billion tons to 0.85 billion tons for the same period. This finding quantitatively illustrates the importance of rural energy consumption as a contributor to China's overall carbon emission. In addition, the analysis of per capita emission from rural energy revealed significant regional disparities and similarities in emission and energy sources used. Both total and per capita CO₂ are significantly higher in the North China, which is largely due to the colder climate and the relatively high economic development levels for multi-demands of energy utilisation. The analysis and results presented here provide substantial information for policy makers in relation to energy and emission targets in China.     

Cost-effective policy instruments for greenhouse gas emission reduction and fossil fuel substitution through bioenergy production in Austria

Climate change mitigation and security of energy supply are important targets of Austrian energy policy. Bioenergy production based on resources from agriculture and forestry is an important option for attaining these targets. To increase the share of bioenergy in the energy supply, supporting policy instruments are necessary. The cost-effectiveness of these instruments in attaining policy targets depends on the availability of bioenergy technologies. Advanced technologies such as second-generation biofuels, biomass gasification for power production, and bioenergy with carbon capture and storage (BECCS) will likely change the performance of policy instruments. This article assesses the cost-effectiveness of energy policy instruments, considering new bioenergy technologies for the year 2030, with respect to greenhouse gas emission (GHG) reduction and fossil fuel substitution. Instruments that directly subsidize bioenergy are compared with instruments that aim at reducing GHG emissions. A spatially explicit modeling approach is used to account for biomass supply and energy distribution costs in Austria. Results indicate that a carbon tax performs cost-effectively with respect to both policy targets if BECCS is not available. However, the availability of BECCS creates a trade-off between GHG emission reduction and fossil fuel substitution. Biofuel blending obligations are costly in terms of attaining the policy targets.