Assessing the uncertainty associated with national greenhouse gas emission inventories:: a case study for Austria

The uncertainty associated with the Austrian Greenhouse Gas emission inventory has been determined for the gases CO₂, CH₄ and N₂O and for the overall greenhouse potential. Expert interviews were conducted to obtain uncertainties in inventory input data. Based on these interviews, error distributions were developed and combined using Monte-Carlo analysis. Results for all sources and gases combined indicate an overall uncertainty between 10.5% and 12% depending on the base year considered. Excluding emissions and the uncertainty associated with forest sinks and natural sources, overall uncertainty decreased by 2% points. The mere ‘random error’, which is considered the level of uncertainty to be achieved with the current methodology (excluding all systematic errors) is 5% points lower. Detailed evaluation shows that much of the overall uncertainty derives from a lack of understanding the processes associated with N₂O emissions from soils. Other important contributors to GHG emission uncertainties are CH₄ from landfills and forests as CO₂ sinks. The uncertainty of the trend has been determined at near 5% points, with solid waste production (landfills) having the strongest contribution. Theoretical considerations do not permit a decrease of the trend uncertainty—even when forest sinks are not considered—below 3% points.     

填埋场沼气发电的温室气体减排效益分析

填埋场沼气是垃圾卫生填埋场产生的可利用资源.以深圳下坪垃圾填埋场为例,定量分析垃圾填埋气体发电的温室气体减排效益.结果表明,填埋场沼气发电具有很好的经济效益和环境效益,可作为与发达国家进行CDM(清洁发展机制)项目合作的优先技术领域.     

Energy and emission benefits of chicken manure biogas production: a case study

Studies on the production of biogas of different organic materials in an anaerobic environment are being carried out all over the world. The most important parameters in these researches can be listed as raw material potential, production processes, economic analyses, and environmental effects. Chicken manure is one of the raw materials used in biogas production. In this study, in addition to the analysis of biogas and energy production potential from chicken manure, greenhouse gas emissions were analyzed to evaluate environmental effects. In Turkey, chicken manure is not adequately processed and causes environmental pollution. The model biogas plant and potential energy generation were researched in this field study. The pilot plant produces 8.58 million m³ of biogas per year by processing about 110 thousand tons of waste. It produces 17 GWh/year of electricity and 16 GWh/year of thermal energy, as well as reducing CO₂ greenhouse gas emissions by 13.86 thousand tons/year.

     

综合考虑减排效益的污染物总量分配方法研究

如何在目标总量控制和容量总量控制间找到契合点,使总量控制既体现环境改善需求,又能促进环保基础设施建设和经济调控目标的实现成为当前的研究重点。基于目标总量控制,探索一种综合考虑减排效益的污染物总量分配方法,构建了以人口、GDP、水资源量、水环境容量和环保投资作为评价指标的环境基尼系数最小化模型,并将其应用于内蒙古自治区COD总量的优化分配。结果表明,与初始分配相比,优化分配后的环境基尼系数总和下降了0.85%,优化后的分配方案更公平、合理。在优化分配过程中,各评价指标间互相制约,较好提高了最终分配结果的科学性和可操作性。     

油气处理场站温室气体甲烷排放特征与量化

油气生产过程是甲烷重点排放源,对气候变化产生显著影响。采用便携式火焰离子检测器 (FID) 和Hi-Flow大流量仪等设备,对我国某油田3座油气处理场站甲烷泄漏排放特征进行了研究,明确了组件泄漏率,量化了重点源项甲烷排放速率,构建了设备设施甲烷排放因子,开展了甲烷排放量核算并提出了管控建议。结果表明,该油田油气处理场站设备组件与管线的甲烷泄漏率为0.7%~1.2%,压力表、阀门和储罐等在泄漏源项中占比较高。不同类型泄漏组件甲烷排放速率具有显著差异,处理场站的甲烷排放速率为111.66~274.63 L·min⁻¹。单个储罐和场站的甲烷排放因子分别为989.9 L·h⁻¹和0.19 L·m⁻³。3座场站年度甲烷排放量为303 783.40 m³,储罐是首要排放源,对总排放量贡献占比为94.1%。组件泄漏导致的甲烷排放主要源于高强度排放源,15%的泄漏点贡献了排放量的88.4%。该研究结果可为油田油气处理场站泄漏防控和温室气体排放控制提供参考。     

电子废弃物资源化全生命周期碳减排效益评估——以废弃电冰箱为例

随着电器电子产品的快速消费和流转,我国正面临电子废弃物国内产生量和国外非法进口量迅速增长的现实问题。废弃电器电子产品处理基金政策(简称"基金"政策)推动了我国电子废弃物资源化产业的发展,带来显著的环境效益。通过解析电子废弃物生命周期过程及其关键的碳减排和碳排放环节,提出了电子废弃物资源化全生命周期碳减排效益评估方法,并以废弃电冰箱为例开展了案例研究。结果表明,制冷剂回收所致碳减排量占废弃电冰箱资源化过程全部碳减排量的92.5%;相对于制冷剂的回收,再生材料产出带来的碳减排效益并不显著;拆解处理所消耗电力的生产是资源化过程碳排放的主要来源,所占比例达89.7%;综合来看,单台废弃电冰箱资源化全生命周期的碳减排效益为1 573.17 kg CO2-eq,2013年我国废弃电冰箱在正规处理体系内资源化带来的碳减排总效益为94.86×104t CO2-eq,"基金"政策驱动效应已初步显现。     

Compositions and greenhouse gas emission factors of flared and vented gas in the Western Canadian Sedimentary Basin

A significant obstacle in evaluating mitigation strategies for flaring and venting in the upstream oil and gas industry is the lack of publicly available data on the chemical composition of the gas. This information is required to determine the economic value of the gas, infrastructure and processing requirements, and potential emissions or emissions credits, all of which have significant impact on the economics of such strategies. This paper describes a method for estimating the composition of solution gas being flared and vented at individual facilities, and presents results derived for Alberta, Canada, which sits at the heart of the Western Canadian Sedimentary Basin. Using large amounts of raw data obtained through the Alberta Energy Resources Conservation Board, a relational database was created and specialized queries were developed to link production stream data, raw gas samples, and geography to create production-linked gas composition profiles for approximately half of the currently active facilities. These were used to create composition maps for the entire region, to which the remaining facilities with unknown compositions were geographically linked. The derived data were used to compute a range of solution gas composition profiles and greenhouse gas emission factors, providing new insight into flaring and venting in the region and enabling informed analysis of future management and mitigation strategies.

Implications: Accurate and transparent determination of environmental impacts of flaring and venting of gas associated with oil production, and potential benefits of mitigation, is severely hampered by the lack of publicly available gas composition data. In jurisdictions within the Western Canadian Sedimentary Basin, frameworks exist for regulating and trading carbon offset credits but current potential for mitigation is limited by a lack of standardized methods for calculating CO₂ equivalent emissions. The composition and emission factor data derived in this paper will be useful to industry, regulators, policy researchers, and entrepreneurs seeking statistically significant and openly available data necessary to manage and mitigate upstream flaring and venting activity and estimate greenhouse gas impacts.     

Life cycle and economic assessment of source-separated MSW collection with regard to greenhouse gas emissions: a case study in China

In China, the continuously increasing amount of municipal solid waste (MSW) has resulted in an urgent need for changing the current municipal solid waste management (MSWM) system based on mixed collection. A pilot program focusing on source-separated MSW collection was thus launched (2010) in Hangzhou, China, to lessen the related environmental loads. And greenhouse gas (GHG) emissions (Kyoto Protocol) are singled out in particular. This paper uses life cycle assessment modeling to evaluate the potential environmental improvement with regard to GHG emissions. The pre-existing MSWM system is assessed as baseline, while the source separation scenario is compared internally. Results show that 23 % GHG emissions can be decreased by source-separated collection compared with the base scenario. In addition, the use of composting and anaerobic digestion (AD) is suggested for further optimizing the management of food waste. 260.79, 82.21, and ?86.21 thousand tonnes of GHG emissions are emitted from food waste landfill, composting, and AD, respectively, proving the emission reduction potential brought by advanced food waste treatment technologies. Realizing the fact, a modified MSWM system is proposed by taking AD as food waste substitution option, with additional 44 % GHG emissions saved than current source separation scenario. Moreover, a preliminary economic assessment is implemented. It is demonstrated that both source separation scenarios have a good cost reduction potential than mixed collection, with the proposed new system the most cost-effective one.     

Agriculture,dairy and fishery farming practices and greenhouse gas emission footprint: a strategic appraisal for mitigation

Rising global population would force farmers to amplify food production substantially in upcoming 3–4 decades. The easiest way to increase grain production is through expanding cropping area by clearing uncultivated land. This is attained by permitting deadly loss of carbon (C) stocks, jeopardizing ecosystem biodiversity and deteriorating environmental quality. We aim to propose key agronomical tactics, livestock management strategy and advance approaches for aquaculture to increase productivity and simultaneously reduce the environmental impacts of farming sector. For this, we considered three major sectors of farming, i.e. agriculture, fishery and dairy. We collected literatures stating approaches or technologies that could reduce GHG emission from these sectors. Thereafter, we synthesized strategies or options that are more feasible and accessible for inclusion in farm sector to reduce GHG emission. Having comprehensively reviewed several publications, we propose potential strategies to reduce GHG emission. Agronomic practices like crop diversification, reducing summer fallow, soil organic carbon sequestration, tillage and crop residue management and inclusion of N2-fixing pulses in crop rotations are some of those. Livestock management through changing animals’ diets, optimal use of the gas produced from manures, frequent and complete manure removal from animal housing and aquaculture management strategies to improve fish health and improve feed conversion efficiency could reduce their GHG emission footprint too. Adapting of effective and economic practices GHG emission footprint reduction potential of farming sector could make farming sector a C neutral enterprise. To overcome the ecological, technological and institutional barriers, policy on trade, tax, grazing practice and GHG pricing should be implemented properly.     

Assessing the impact of air pollution controls on carbon monoxide reduction: the case of Taiwan

An inevitable external effect of economic growth, especially for countries in the early stages of growth, is air pollution. The Taiwan experience is a case in point. To control the pollution, Taiwan created the Environmental Protection Administration. This paper assesses the impact of the administration's abatement policy on a primary component of air pollution, carbon monoxide. Using recent advances in time series analysis, we fail to find evidence of a successful policy. If carbon monoxide is to be significantly reduced, it appears that the Administration needs to adopt more stringent standards and innovative approaches.     

Climate change policy in the peripheral countries of Europe: Ireland as a case study

Owing to their relative underdevelopment, the 'cohesion' countries of the European Union have been allowed to increase emissions above the 1990 base within the EU 'envelope'. However, they face daunting challenges in meeting the agreed targets, because it requires breaking the link between rising gross domestic product and rising energy consumption at a relatively early stage in the economic development cycle. This paper examines the extreme case of Ireland, which is experiencing the most rapid growth in the EU. It shows that Ireland has already reached its emissions ceiling. The best opportunities for reducing emissions lie in energy supply, industry, and the household sector. A mix of policy instruments is required. Emissions trading seems to be the most effective policy instrument for reducing greenhouse gas emissions from energy supply and large industry. Such a policy would provide a stimulus for continuous improvement, without which Ireland's limit will be breached.     

城市水务系统碳排放测算及减碳对策分析：以成都市为例

城市水务系统是单位产值能耗较高且与各行各业联系紧密的行业。在“双碳”背景下,开展碳排放核算及减碳策略研究是水务系统高质量发展的重要内容。通过构建成都市水务系统碳排放框架,基于大量统计数据,对水务系统中各个环节 (取、制、供、排等) 产生的直接及间接碳排放进行统筹核算。结果显示,2019年成都市水务系统碳排放总量约为70.3万吨 (以CO₂计) ,主要碳排放领域为污水处理系统,其中的污水处理及污泥处理处置环节的碳排放贡献最为突出。基于核算结果,对水务系统减污降碳目标及实现路径进行系统分析及定量测算,提出包括“节水优先、高效管网、源头提质、低碳工艺及能源回用”的五大策略推进水务系统减碳转型,为成都市及类似城市的“双碳”水务系统建设提供参考。     

Assessing the environmental fate of chemicals of emerging concern: a case study of the polybrominated diphenyl ethers

It is suggested that assessments of chemicals of emerging concern can be rationally structured around a multistage process in which fate and risk are evaluated with increasing accuracy as new data become available. An initial tentative and approximate assessment of fate and risk can identify key data gaps and justify and direct further investigations, which progressively improve the reliability of the assessment. This approach is demonstrated for a class of chemicals, the polybrominated diphenyl ethers (PBDEs), which is of increasing concern, but about which there is presently a lack of comprehensive data on properties, sources, fate and effects. Specifically, 20 PBDE congeners are investigated using the suggested approach and research needs are identified.     

Estimating and comparing greenhouse gas emissions with their uncertainties using different methods: A case study for an energy supply utility

Energy supply utilities release significant amounts of greenhouse gases (GHGs) into the atmosphere. It is essential to accurately estimate GHG emissions with their uncertainties, for reducing GHG emissions and mitigating climate change. GHG emissions can be calculated by an activity-based method (i.e., fuel consumption) and continuous emission measurement (CEM). In this study, GHG emissions such as CO₂, CH₄, and N₂O are estimated for a heat generation utility, which uses bituminous coal as fuel, by applying both the activity-based method and CEM. CO₂ emissions by the activity-based method are 12–19% less than that by the CEM, while N₂O and CH₄ emissions by the activity-based method are two orders of magnitude and 60% less than those by the CEM, respectively. Comparing GHG emissions (as CO₂ equivalent) from both methods, total GHG emissions by the activity-based methods are 12–27% lower than that by the CEM, as CO₂ and N₂O emissions are lower than those by the CEM. Results from uncertainty estimation show that uncertainties in the GHG emissions by the activity-based methods range from 3.4% to about 20%, from 67% to 900%, and from about 70% to about 200% for CO₂, N₂O, and CH₄, respectively, while uncertainties in the GHG emissions by the CEM range from 4% to 4.5%. For the activity-based methods, an uncertainty in the Intergovernmental Panel on Climate Change (IPCC) default net calorific value (NCV) is the major uncertainty contributor to CO₂ emissions, while an uncertainty in the IPCC default emission factor is the major uncertainty contributor to CH₄ and N₂O emissions. For the CEM, an uncertainty in volumetric flow measurement, especially for the distribution of the volumetric flow rate in a stack, is the major uncertainty contributor to all GHG emissions, while uncertainties in concentration measurements contribute a little to uncertainties in the GHG emissions.

Implications:Energy supply utilities contribute a significant portion of the global greenhouse gas (GHG) emissions. It is important to accurately estimate GHG emissions with their uncertainties for reducing GHG emissions and mitigating climate change. GHG emissions can be estimated by an activity-based method and by continuous emission measurement (CEM), yet little study has been done to calculate GHG emissions with uncertainty analysis. This study estimates GHG emissions and their uncertainties, and also identifies major uncertainty contributors for each method.     

Assessing the economic benefits and costs of conservation tillage

The economic benefits of the adoption of conservation tillage depend on site-specific factors, including soil characteristics, local climatic conditions, cropping patterns, and other attributes of the overall farming operation. While it is possible to draw some general inferences about components of economic returns and costs, a comprehensive assessment of the net private benefits from greater use of conservation tillage is not feasible.     

Application of dynamic models to estimate greenhouse gas emission by wastewater treatment plants of the pulp and paper industry

Greenhouse gas (GHG) emission in wastewater treatment plants of the pulp-and-paper industry was estimated by using a dynamic mathematical model. Significant variations were shown in the magnitude of GHG generation in response to variations in operating parameters, demonstrating the limited capacity of steady-state models in predicting the time-dependent emissions of these harmful gases. The examined treatment systems used aerobic, anaerobic, and hybrid—anaerobic/aerobic—biological processes along with chemical coagulation/flocculation, anaerobic digester, nitrification and denitrification processes, and biogas recovery. The pertinent operating parameters included the influent substrate concentration, influent flow rate, and temperature. Although the average predictions by the dynamic model were only 10 % different from those of steady-state model during 140 days of operation of the examined systems, the daily variations of GHG emissions were different up to ±30, ±19, and ±17 % in the aerobic, anaerobic, and hybrid systems, respectively. The variations of process variables caused fluctuations in energy generation from biogas recovery by ±16, ±17, and ±14 % in the three examined systems, respectively. The lowest variations were observed in the hybrid system, showing the stability of this particular process design.     

Allocation of carbon emission allowance based on DLA-GA model: a case study in China

Environmental Science and Pollution Research - To achieve China’s determined contributions by 2030 and establish nationwide carbon emission trading system (ETS) which main participants are...     

Sulfur deposition simulations over China, Japan, and Korea: a model intercomparison study for abating sulfur emission

In response to increasing trends in sulfur deposition in Northeast Asia, three countries in the region (China, Japan, and Korea) agreed to devise abatement strategies. The concepts of critical loads and source?Creceptor (S?CR) relationships provide guidance for formulating such strategies. Based on the Long-range Transboundary Air Pollutants in Northeast Asia (LTP) project, this study analyzes sulfur deposition data in order to optimize acidic loads over the three countries. The three groups involved in this study carried out a full year (2002) of sulfur deposition modeling over the geographic region spanning the three countries, using three air quality models: MM5-CMAQ, MM5-RAQM, and RAMS-CADM, employed by Chinese, Japanese, and Korean modeling groups, respectively. Each model employed its own meteorological numerical model and model parameters. Only the emission rates for SO₂ and NO_x obtained from the LTP project were the common parameter used in the three models. Three models revealed some bias from dry to wet deposition, particularly the latter because of the bias in annual precipitation. This finding points to the need for further sensitivity tests of the wet removal rates in association with underlying cloud?Cprecipitation physics and parameterizations. Despite this bias, the annual total (dry plus wet) sulfur deposition predicted by the models were surprisingly very similar. The ensemble average annual total deposition was 7,203.6?±?370 kt S with a minimal mean fractional error (MFE) of 8.95?±?5.24?% and a pattern correlation (PC) of 0.89?C0.93 between the models. This exercise revealed that despite rather poor error scores in comparison with observations, these consistent total deposition values across the three models, based on LTP group's input data assumptions, suggest a plausible S?CR relationship that can be applied to the next task of designing cost-effective emission abatement strategies.     

Biofiltration of trichloroethylene-contaminated air: a pilot study

This project demonstrated the biofiltration of a trichloroethylene (TCE)-contaminated airstream generated by air stripping groundwater obtained from several wells located at the Anniston Army Depot, Anniston, AL. The effects of several critical process variables were investigated to evaluate technical and economic feasibility, define operating limits and preferred operating conditions, and develop design information for a full-scale biofilter system. Long-term operation of the demonstration biofilter system was conducted to evaluate the performance and reliability of the system under variable weather conditions. Propane was used as the primary substrate necessary to induce the production of a nonspecific oxygenase. Results indicated that the process scheme used to introduce propane into the biofiltration system had a significant impact on the observed TCE removal efficiency. TCE degradation rates were dependent on the inlet contaminant concentration as well as on the loading rate. No microbial inhibition was observed at inlet TCE concentrations as high as 87 parts per million on a volume basis.     

The impact of greenhouse gas emissions on the performance of water companies: a dynamic assessment

Environmental Science and Pollution Research - The water industry plays an important role in reducing greenhouse gas (GHG) emissions and therefore, moving to a low-carbon urban water cycle is of...