Modern Biomass Conversion Technologies

This article gives an overview of the state-of-the-art of key biomass conversion technologies currently deployed and technologies that may play a key role in the future, including possible linkage to CO₂ capture and sequestration technology (CCS). In doing so, special attention is paid to production of biofuels for the transport sector, because this is likely to become the key emerging market for large-scale sustainable biomass use. Although the actual role of bio-energy will depend on its competitiveness with fossil fuels and on agricultural policies worldwide, it seems realistic to expect that the current contribution of bio-energy of 40–55 EJ per year will increase considerably. A range from 200 to 300 EJ may be observed looking well into this century, making biomass a more important energy supply option than mineral oil today. A key issue for bio-energy is that its use should be modernized to fit into a sustainable development path. Especially promising are the production of electricity via advanced conversion concepts (i.e. gasification and state-of-the-art combustion and co-firing) and modern biomass derived fuels like methanol, hydrogen and ethanol from ligno-cellulosic biomass, which can reach competitive cost levels within 1–2 decades (partly depending on price developments with petroleum). Sugar cane based ethanol production already provides a competitive biofuel production system in tropical regions and further improvements are possible. Flexible energy systems, in which biomass and fossil fuels can be used in combination, could be the backbone for a low risk, low cost and low carbon emission energy supply system for large scale supply of fuels and power and providing a framework for the evolution of large scale biomass raw material supply systems. The gasification route offers special possibilities to combine this with low cost CO₂ capture (and storage), resulting in concepts that are both flexible with respect to primary fuel input as well as product mix and with the possibility of achieving zero or even negative carbon emissions. Prolonged RD&D efforts and biomass market development, consistent policy support and international collaboration are essential to achieve this.     

西藏生物质能开发的资源、环境基础分析

开发生物质能是缓解能源供应紧张、环境污染严重这两大难题的理性选择。而由于生物质能蕴藏于生物质中,生物质又与区域自然地理特征息息相关,因此,各地发展生物质能具有明显的区域特性,不可一刀切。论文分析了西藏发展生物质能的资源条件和环境基础,认为西藏生物质能资源总量大而单位面积的生物净初级生产量不高,自然环境脆弱且生物质能利用与环境关系紧张。在前人关于西藏的太阳能、生物量、净初级生产量研究基础上,从生物质能转化过程的角度,提出了可利用生产量的概念及生物质能可持续利用的模式,继而估算出了西藏的生物质能资源总量2400×10⁴tce/a。最后,在肯定西藏生物质能开发的可行性的同时,提出了因地制宜,适度开发的战略。     

Bio-energy policies in a global context

Against the background of an increasing global demand for bio-energy, the need for sustainability standards and a certification system ensuring sustainable production and trade has grown rapidly. Nevertheless, there is currently no specific forum for discussions on how to deal with biomass trade at the multilateral level. Distortions in agricultural and energy trade regimes, the myriad of standards and the lack of a clear biomass classification in the multilateral trade regime suggest that bio-energy products may not deliver sustainable development gains for all trading partners. This paper analyses then the global impact of bio-energy policies on biomass production and trade, paying particular attention to sustainable development in the bio-energy sector. It examines how a possible reduction and elimination of trade barriers as well as a phasing out of trade distorting support measures would contribute to the development of a global sustainable bio-energy market.     

National forest policy as a platform for biosphere carbon management: the case of community forestry in Cameroon

Little attention has been given to the development of national policies relevant for the uptake, development and implementation of Clean Development Mechanism (CDM) projects. In this paper we examine the compatibility between forestry and related policy provisions in Cameroon and the CDM provisions for Land Use, Land Use Change and Forestry (LULUCF). For each CDM requirement such as eligibility, additionality, impact assessment and sustainable development, relevant national forestry policy questions are identified. These relevant policy questions are applied to community forestry policy instruments in Cameroon to analyse the likelihood that they can enhance or inhibit the uptake and implementation of biosphere carbon projects. We found that choosing a single crown cover value (from between 10 and 30%) presented a serious dilemma for Cameroon given its diverse vegetation cover. Adopting any single value within this range is unlikely to optimize national carbon management potential. The current forest institutional and regulatory policy framework in Cameroon is inadequate for promoting carbon forestry under current CDM rules. We conclude that national policy in Cameroon would need to recognise the need for and adopt a pro-active approach for biosphere carbon management, engaging in institutional development, integrated planning, project development support and providing adequate regulatory frameworks to enhance sustainable development through CDM projects. The need for CDM/Kyoto capacity building support for proactive national and local policy development is highlighted.     

Public policy as a part of transforming energy systems: framing bioenergy in Finnish energy policy

Government interventions have been identified as important for energy systems change, because they can either facilitate or hinder transitions toward more sustainable energy systems. This article analyses how bioenergy options have been framed in Finnish policy strategies and how the framing has changed over time. The empirical material includes the content of 15 government programmes and nine national energy/climate strategies. On the basis of this assessment, both the link between bioenergy framings in strategies and the actual transformation of Finnish bioenergy systems are explored.On the basis of bioenergy framings, the development of energy policy can be divided into three phases: support for domestic energy sources in 1979-1991, support for wood- and industry-based bioenergy in 1992-1998, and diversified bioenergy in the context of climate change in 1999-2010. For two decades, primarily wood-based bioenergy was supported despite alternative technological developments occurring elsewhere. After the turn of the millennium, the importance of climate policy increased and alternative bioenergy sources were raised on the government policy agenda, also resulting in some new policy instruments. Rather than adopting a visionary outlook to guide system transformation, climate and energy policy has strengthened those technological options that have been selected elsewhere. If public policies are to enhance the shift toward low-carbon, sustainable energy systems, they would need to be more comprehensive, be more consistent over time, and emphasise energy use more.     

Sustainability criteria for bioenergy systems: results from an expert survey

Environmental impacts associated with the use of fossil fuels, rising prices, potential limitations in supply and concerns about regional and national security are driving the development and use of biomass for bioenergy, biofuels and bioproducts. However, the use of biomass does not automatically imply that its production, conversion and use are sustainable. In order to operationalize sustainability assessments of biomass systems, it is crucial to identify critical criteria, but keep their number and measurement at a manageable level. The selection of these criteria can vary depending on individual's expertise, geographical region where they work, and spatial scale they are focused on. No clear consensus has yet emerged on what experts consider as critical indicators of sustainability. Objectives of this paper were to analyze how key experts perceive the 35 sustainability criteria for bioenergy found in emerging sustainability assessment frameworks and to identify levels of agreement and uncertainty. Experts were asked to rate the criteria for attributes of relevance, practicality, reliability, and importance.Perceptions of the importance of the 35 criteria varied among the experts surveyed. Only two criteria, energy balance and greenhouse gas balance, were perceived as critical by more than half of the respondents. Social criteria and locally applied criteria were generally ranked low for all four attributes. Seven of the 12 criteria scored as most important focused on environmental issues, four were social and only one was economic. Of the 12 most important criteria, seven were ranked low in practicality and reliability indicating that mechanisms to assess a number of important criteria need to be developed. The spatial scale the experts worked at and their profession explained most of the differences in importance ranking between experts, while regional focus had minimal effect. Criteria that were ranked low for importance, were characterized by a lack of consensus, suggesting the need for further debate regarding their inclusion in sustainability assessments.Outcomes of the survey provide a foundation for further discussions and development of sustainability assessments for bioenergy systems and may also provide a basis for assessing individual bioenergy projects within their specific geographic, ecological, societal, and technological context and scale.     

Forest carbon accounting methods and the consequences of forest bioenergy for national greenhouse gas emissions inventories

While bioenergy plays a key role in strategies for increasing renewable energy deployment, studies assessing greenhouse gas (GHG) emissions from forest bioenergy systems have identified a potential trade-off of the system with forest carbon stocks. Of particular importance to national GHG inventories is how trade-offs between forest carbon stocks and bioenergy production are accounted for within the Agriculture, Forestry and Other Land Use (AFOLU) sector under current and future international climate change mitigation agreements. Through a case study of electricity produced using wood pellets from harvested forest stands in Ontario, Canada, this study assesses the implications of forest carbon accounting approaches on net emissions attributable to pellets produced for domestic use or export. Particular emphasis is placed on the forest management reference level (FMRL) method, as it will be employed by most Annex I nations in the next Kyoto Protocol Commitment Period. While bioenergy production is found to reduce forest carbon sequestration, under the FMRL approach this trade-off may not be accounted for and thus not incur an accountable AFOLU-related emission, provided that total forest harvest remains at or below that defined under the FMRL baseline. In contrast, accounting for forest carbon trade-offs associated with harvest for bioenergy results in an increase in net GHG emissions (AFOLU and life cycle emissions) lasting 37 or 90 years (if displacing coal or natural gas combined cycle generation, respectively). AFOLU emissions calculated using the Gross-Net approach are dominated by legacy effects of past management and natural disturbance, indicating near-term net forest carbon increase but longer-term reduction in forest carbon stocks. Export of wood pellets to EU markets does not greatly affect the total life cycle GHG emissions of wood pellets. However, pellet exporting countries risk creating a considerable GHG emissions burden, as they are responsible for AFOLU and bioenergy production emissions but do not receive credit for pellets displacing fossil fuel-related GHG emissions. Countries producing bioenergy from forest biomass, whether for domestic use or for export, should carefully consider potential implications of alternate forest carbon accounting methods to ensure that potential bioenergy pathways can contribute to GHG emissions reduction targets.     

Institutional challenges to climate change adaptation: A case study on policy action gaps in Uganda

Despite the considerable progress made in the last decade towards building governance systems for climate change adaptation in Africa, implementation still limits positive responses. This study applies an iterative process of field assessments and literature reviews across multiple governance levels and spatial scales to identify constraints to effective formulation and implementation of climate change related policies and strategies in Uganda. Data was collected through sex-segregated participatory vulnerability assessments with farming communities in Rakai district, policy document reviews, and interviews with policy actors at national and district levels. Findings reveal that the key challenges to effective policy implementation are diverse and cut across the policy development and implementation cycle. Policies are mainly developed by central government agencies; other actors are insufficiently involved while local communities are excluded. There is also a communication disconnect between national, district, and community levels. Coupled with limited technical capacity and finances, political interference, and absence of functional implementation structures across these levels, climate change adaptation becomes constrained. We propose strategies that enhance linkages between levels and actors, which will improve policy formulation, implementation and ultimately adaptation by smallholders.     

Global and regional potential for bioenergy from agricultural and forestry residue biomass

As co-products, agricultural and forestry residues represent a potential low cost, low carbon, source for bioenergy. A method is developed for estimating the maximum sustainable amount of energy potentially available from agricultural and forestry residues by converting crop production statistics into associated residue, while allocating some of this resource to remain on the field to mitigate erosion and maintain soil nutrients. Currently, we estimate that the world produces residue biomass that could be sustainably harvested and converted into nearly 50 EJ yr⁻¹ of energy. The top three countries where this resource is estimated to be most abundant are currently net energy importers: China, the United States (US), and India. The global potential from residue biomass is estimated to increase to approximately 50–100 EJ yr⁻¹ by mid- to late- century, depending on physical assumptions such as of future crop yields and the amount of residue sustainably harvestable. The future market for biomass residues was simulated using the Object-Oriented Energy, Climate, and Technology Systems Mini Climate Assessment Model (O^bjECTS MiniCAM). Utilization of residue biomass as an energy source is projected for the next century under different climate policy scenarios. Total global use of residue biomass is estimated to be 20–100 EJ yr⁻¹ by mid- to late- century, depending on the presence of a climate policy and the economics of harvesting, aggregating, and transporting residue. Much of this potential is in developing regions of the world, including China, Latin America, Southeast Asia, and India.     

European trade of forest products in the presence of EU policy

Increasing the share of renewable energy is of principal concern for the EU energy policy. A number of policies have been adopted, and, in part, been implemented by the EU member countries. An increasing share of renewable energy implies an increasing utilisation of biofuels in general and of forest-based biomass in particular. However, in the EU, the endowment and uses of forest-base biomass are diverse suggesting that an increasing trade would become necessary in order to cost effectively increase the utilisation of forest-based biomass. The purpose of this study is to, in the presence of EU energy policy, quantify and analyse possible trade levels for forest fuels in the EU. Particularly, the consequences on trade after implementing the White Paper and the RES-E Directive are analysed. Investigating the European trade in forest fuels is important for understanding how industry sectors in the EU will be affected by the policies. The results suggest that the implementation of the White Paper and the RES-E Directive will increase the trade in forest fuels, resulting in total trade increases of up to 67 percent. Furthermore, the national net trading levels are possible to derive. Depending on policy implementation the results differ – a country that was net importing given the White Paper implementation can instead be net exporting when applying the RES-E Directive. The fact that the policy implementations will increase the trade may mitigate potential industry problems to secure the needed inputs. On the other hand, the integration of countries increases the possibility for some industries to increase their production even more, possibly strengthening any input scarcity problems. It is therefore not possible to generally conclude if a more integrated European forest fuel market, and hence an increased European forest fuel trade, will mitigate industry problems to secure their needed inputs or not.     

The implementation of Natura 2000 in forests: A trans- and interdisciplinary assessment of challenges and choices

Natura 2000 is the core of the EU's biodiversity conservation policy. 50% of the overall protected area under Natura 2000 is forest. Yet, comparatively little is known about the implementation of the policy in forests. Building on a rich set of social and natural science data, and an inter- and transdisciplinary discussion process involving scientists from different disciplines as well as EU, national and local stakeholders, this paper identifies five important challenges related to the implementation of Natura 2000 in forests: (1) the balancing of biodiversity conservation and timber production, (2) the integration of conservation (science) and local stakeholders’ demands, (3) climate change, (4) lacking and less effective funding, and (5) conflicts related to other sectoral policies. Subsequently, five possible pathways to tackle these challenges are proposed: (1) a learning approach through better communication and transparency, (2) a pathway emphasizing the role of conservation science in developing management strategies and responding to climate change, (3) an approach of better integrating Europe's citizens in the design and implementation of the policy, (4) an approach highlighting the necessity of an effective funding strategy, and (5) the vision to work towards an integrated European land use and conservation policy. In conclusion, we emphasize, on one hand, the distinct character of the five pathways but, on the other hand, underline that probably all of them need to be followed in order to make the implementation of Natura 2000 in Europe's forests a success story.     

Pursuing an integrated development and climate policy framework in Africa: options for mainstreaming

Climate change presents a major threat to the prospects for sustained economic development in Africa. In spite of this, climate change concerns do not feature prominently in the implementation of national and regional development programmes. The present paper identifies the likely trade-offs and synergies that may emerge from an integrated ‘development-climate’ approach to policy making. Also, the paper presents the case for the formulation and evaluation of an integrated policy approach based on four principle criteria, including; long-term environmental effectiveness, equity considerations, cost-effectiveness and the institutional compatibility of the policy combinations. What is more? The paper suggests specific options for mainstreaming climate change adaptation and mitigation in various sectoral development agenda such as; agricultural intensification, poverty eradication, rural development, urban renewal, energy security of supply and trade. Given the wide divergence of socio-economic systems and the peculiar challenges faced by individual countries in the continent, further research is required on robust country-specific strategies for pursuing an integrated development-climate policy framework.     

中国生活垃圾分类政策制度的发展演变历程

系统考察我国垃圾分类政策的演化过程、阶段特征和取得成效,是合理制定和有效执行垃圾分类政策的重要基础,有助于新时代垃圾分类体系和垃圾分类制度的加快建立和实施。以垃圾分类政策制度的历史演变为主线,将中华人民共和国成立以来的垃圾分类政策历史发展划分为5个阶段:1）基于垃圾回收利用的分类收集启蒙阶段（1957—1991年）;2）生活垃圾分类法律法规制定的初期阶段（1992—1999年）;3）基于垃圾分类实践的分类标准制定阶段（2000—2015年）;4）生活垃圾分类制度筹建阶段（2015—2016年）;5）生活垃圾分类制度的确立和实施阶段（2017年至今）。分析表明,我国初步形成了符合国情且较为完善的垃圾分类政策制度体系,垃圾分类制度的实施,可显著改善生活环境,节约资源,提高社会文明水平,对推动绿色发展、建设美丽中国具有十分重要的意义。     

Role of Bio-Energy Plantations for Carbon-Dioxide Mitigation with Special Reference to India

Fuelwood plays an important role in the rural economy of the developing countries of Asia and Africa. Optimizing energy fixation in forest trees through high density energy plantations (HDEP), gasification of wood, and conversion of forest tree biomass, are some of the potential areas whereby additional research and development input for efficient management of atmospheric carbon in our energy system can be incorporated. For example, the photosynthetic efficiency of forest trees is rarely above 0.5%, which on the basis of theoretical considerations can be increased by up to 6.6%. Thus there is an ample scope to improve the efficiency up to 1%, which amounts to doubling of the productivity of the forests. Recent policy changes and experiences with wood-based bio-energy programmes in several countries indicate that woodfuels may become increasingly attractive as industrial energy sources. Use of biodiesel and the formulation of a project for undertaking 13.4 million ha of Jatropha plantations in India highlight the seriousness with which the Government of India is promoting carbon neutral energy plantations. The cost of establishment of plantations primarily for fuel production and its conversion to energy are major deterrents in this pursuit. Some of the issues in developing countries, like low productivity on marginal lands, degraded forest lands, and unorganized units for biomass energy conversion, result in cost escalation as compared to other energy sources. This paper revisits the scope for raising energy plantations, a comparison of the direct and indirect mitigation potential uses of plantations as an adaptation strategy through reforestation and afforestation projects for climate change mitigation and socio-economic issues to make this venture feasible in developing countries.     

农作物生物质能的遥感估算——以广东省为例

农作物秸秆生物质能项目是生物质能最具产业化和规模化的集约利用方式之一,也是解决能源可持续发展和环境问题的有效途径之一。目前国内外对农作物秸秆生物质能总量估算都是基于传统的实地调查和统计数据来获取,缺乏详细的生物质能的空间分布信息,对生物质能源利用与规划指导粗略。论文以广东省为例,利用基于BIOME鄄BGC模型改进的MOD17A2/A3数据和TM数据对生物质能总量及空间格局进行估算和分析。根据生物质能可用部分的影响因素,建立可用生物质能决策模型。为能源消耗量大的省份在生物质能的有效利用方面提供了依据。     

Bioenergy to mitigate for climate change and meet the needs of society,the economy and the environment

Changes towards environmental improvementsare becoming more politically acceptableglobally, especially in developedcountries. Society is slowly moving towardsseeking more sustainable productionmethods, waste minimisation, reduced airpollution from vehicles, distributed energygeneration, conservation of native forests,and reduction of greenhouse gas (GHG)emissions. Modern biomass, when used tosupply useful bioenergy services, has arole to play in each one of theseenvironmental drivers at both the large andsmall scales.This paper describes recent developments inbiomass supply and the technologies for itsconversion to bioenergy including biofuelsfor transport. It examines the economic,environmental and social benefits andidentifies barriers to bioenergy projectimplementation. Future opportunities forbiomass as a carbon (C) sink, a C offsetand a potential source of renewablehydrogen are discussed.Whether or not a bioenergy project iseconomically viable, as well as being trulyrenewable, sustainable and environmentallysound, is determined mainly by the sourceof biomass. The social benefits from usingbiomass are also valuable, though they areoften not clearly presented when proposingnew bioenergy projects or conductinganalyses of existing plants. Employmentrates per MWh or per GJ exceed those whenusing fossil fuel supplies to provide thesame energy service. `Ownership' bystakeholders and local communities at anearly stage in the development process isthe key to successful project developmentin order to share the benefits. Bioenergyhas a significant global role to play inthe mitigation of atmospheric GHG concentrations.     

The impact of climate change mitigation on water demand for energy and food: An integrated analysis based on the Shared Socioeconomic Pathways

Climate change mitigation, in the context of growing population and ever increasing economic activity, will require a transformation of energy and agricultural systems, posing significant challenges to global water resources. We use an integrated modelling framework of the water-energy-land-climate systems to assess how changes in electricity and land use, induced by climate change mitigation, impact on water demand under alternative socioeconomic (Shared Socioeconomic Pathways) and water policy assumptions (irrigation of bioenergy crops, cooling technologies for electricity generation). The impacts of climate change mitigation on cumulated global water demand across the century are highly uncertain, and depending on socioeconomic and water policy conditions, they range from a reduction of 15,000 km³ to an increase of more than 160,000 km³. The impact of irrigation of bioenergy crops is the most prominent factor, leading to significantly higher water requirements under climate change mitigation if bioenergy crops are irrigated. Differences in socioeconomic drivers and fossil fuel availability result in significant differences in electricity and bioenergy demands, in the associated electricity and primary energy mixes, and consequently in water demand. Economic affluence and abundance of fossil fuels aggravate pressures on water resources due to higher energy demand and greater deployment of water intensive technologies such as bioenergy and nuclear power. The evolution of future cooling systems is also identified as an important determinant of electricity water demand. Climate policy can result in a reduction of water demand if combined with policies on irrigation of bioenergy, and the deployment of non-water-intensive electricity sources and cooling types.     

太湖梅梁湾浮游动物群落结构长期变化特征(1997~2017年)

浮游动物作为水体食物链的重要组成部分,在湖泊生态系统中发挥着重要作用.然而,作为水质重要监测指标,由于浮游动物群落结构长期连续监测数据的缺失,导致关于浮游动物群落结构长期变化特征的认识较为缺乏.基于太湖梅梁湾1997~2017年逐月连续监测数据,研究了浮游动物群落结构的长期变化特征,探讨了其与环境因子的关系.结果显示,在此期间,太湖梅梁湾浮游动物丰度和生物量均显著下降（P<0.05）.其中,轮虫和桡足类丰度和生物量均缓慢下降,枝角类丰度处于波动而生物量表现为显著下降（P<0.05）.枝角类生物量对太湖梅梁湾浮游动物生物量的贡献最大.小型的枝角类和桡足类的优势度随着轮虫丰度的降低而增大,浮游动物的平均体型显著减小（P<0.05）,浮游动物呈现出小型化演化特征,并潜在减弱对浮游植物的下行效应.此外,浮游动物丰度和生物量在春季呈上升趋势而在秋冬季呈下降趋势,并在9月达到最大值1406.70 ind.·L^-1和25.64 mg·L^-1.而在夏季它们的变化趋势则相反.Pearson相关性分析显示,浮游动物群落结构主要与水体物理特征（碱度、电导率、水深、悬浮物质和水温）、叶绿素a和氮元素密切相关（P<0.05）,说明太湖梅梁湾水体富营养化对浮游动物的群落结构具有重要影响.     

Millennium development goals and clean development: synergies in the Pacific

This paper addresses synergies between the Millennium Development Goals (MDGs) and the Clean Development Mechanism (CDM), and considers how the CDM can facilitate the MDGs in Pacific Island Countries (PICs). To date, only 6 CDM projects have been registered in PICs, highlighting the ‘lose-lose’ business case that applies to this type of project development. This paper identifies constraints on and opportunities for CDM project development in PICs, and proposes a range of specific policy reform measures that could alter existing negative investment profiles. Key findings are that small-scale agricultural projects providing renewable energy from existing sources of biomass (currently seen as waste) are ideal candidates for CDM investment in PICs, and that the single most important reform to facilitate CDM activity and contribute to achieving the MDGs would be the implementation of a regional approach to CDM administration, in which a regional body became the designated CDM Authority for all states in the region. This would offset investment risk, improve governance transparency, and facilitate a targeted approach to sustainable development activities in the Pacific region.