Waste Management and Climate Change

Waste management has at least five types of impacts on climate change, attributable to: (1) landfill methane emissions; (2) reduction in industrial energy use and emissions due to recycling and waste reduction; (3) energy recovery from waste; (4) carbon sequestration in forests due to decreased demand for virgin paper; and (5) energy used in long-distance transport of waste: A recent USEPA study provides estimates of overall per-tonne greenhouse gas reductions due to recycling. Plausible calculations using these estimates suggest that countries such as the US or Australia could realise substantial greenhouse gas reductions through increased recycling, particularly of paper.     

The potential contribution of sustainable waste management to energy use and greenhouse gas emission reduction in the Netherlands

Future limitations on the availability of selected resources stress the need for increased material efficiency. In addition, in a climate-constrained world the impact of resource use on greenhouse gas emissions should be minimized. Waste management is key to achieve sustainable resource management. Ways to use resources more efficiently include prevention of waste, reuse of products and materials, and recycling of materials, while incineration and anaerobic digestion may recover part of the embodied energy of materials. This study used iWaste, a simulation model, to investigate the extent to which savings in energy consumption and CO₂ emissions can be achieved in the Netherlands through recycling of waste streams versus waste incineration, and to assess the extent to which this potential is reflected in the LAP2 (currently initiated policy). Three waste streams (i.e. household waste, bulky household waste, and construction and demolition waste) and three scenarios compare current policy to scenarios that focus on high-quality recycling (Recycling+) or incineration with increased efficiency (Incineration+). The results show that aiming for more and high-quality recycling can result in emission reductions of 2.3 MtCO₂ annually in the Netherlands compared to the reference situation in 2008. The main contributors to this reduction potential are found in optimizing the recycling of plastics (PET, PE and PP), textiles, paper, and organic waste. A scenario assuming a higher energy conversion efficiency of the incinerator treating the residual waste stream, achieves an emission reduction equivalent to only one third (0.7 MtCO₂/year) of the reduction achieved in the Recycling+ scenario. Furthermore, the results of the study show that currently initiated policy only partially realizes the full potential identified. A focus on highest quality use of recovered materials is essential to realize the full potential energy and CO₂ emission reduction identified for the Netherlands. Detailed economic and technical analyses of high quality recycling are recommended to further evaluate viable integrated waste management policies.     

An energetic life cycle assessment of C&D waste and container glass recycling in Cape Town,South Africa

This study presents the results of a comparative life cycle assessment (LCA) on the energy requirements and greenhouse gas (GHG) emission implications of recycling construction and demolition (C&D) rubble and container glass in Cape Town, South Africa. Cape Town is a medium sized city in a developing country with a growing population and a rising middle class, two factors that are resulting in increased generation of solid waste. The City is constrained in terms of landfill space and competing demands for municipal resources.The LCA assessment was based on locally gathered data, supplemented with ecoinvent life cycle inventory data modified to the local context. The results indicated that recycling container glass instead of landfilling can achieve an energy savings of 27% and a GHG emissions savings of 37%, with a net savings still being achieved even if collection practices are varied. The C&D waste results, however, showed net savings only for certain recycling strategies. Recycling C&D waste can avoid up to 90% of the energy and GHG emissions of landfilling when processed and reused onsite but, due to great dependence on haulage distances, a net reduction of energy use and GHG emissions could not be confidently discerned for offsite recycling. It was also found that recycling glass achieves significantly greater savings of energy and emissions than recycling an equivalent mass of C&D waste.The study demonstrated that LCA provides an important tool to inform decisions on supporting recycling activities where resources are limited. It also confirmed other researchers’ observations that strict adherence to the waste management hierarchy will not always result in the best environmental outcome, and that more nuanced analysis is required. The study found that the desirability of recycling from an energy and climate perspective cannot be predicted on the basis of whether such recycling conserves a non-renewable material. However, recycling that replaces a virgin product from an energy-intensive production process appears to be more robustly beneficial than recycling that replaces a product with little embodied energy. Particular caution is needed when applying the waste management hierarchy to the latter situations.     

Assessment of the greenhouse effect impact of technologies used for energy recovery from municipal waste: A case for England

Waste management activities contribute to global greenhouse gas emissions approximately by 4%. In particular the disposal of waste in landfills generates methane that has high global warming potential. Effective mitigation of greenhouse gas emissions is important and could provide environmental benefits and sustainable development, as well as reduce adverse impacts on public health. The European and UK waste policy force sustainable waste management and especially diversion from landfill, through reduction, reuse, recycling and composting, and recovery of value from waste. Energy from waste is a waste management option that could provide diversion from landfill and at the same time save a significant amount of greenhouse gas emissions, since it recovers energy from waste which usually replaces an equivalent amount of energy generated from fossil fuels. Energy from waste is a wide definition and includes technologies such as incineration of waste with energy recovery, or combustion of waste-derived fuels for energy production or advanced thermal treatment of waste with technologies such as gasification and pyrolysis, with energy recovery. The present study assessed the greenhouse gas emission impacts of three technologies that could be used for the treatment of Municipal Solid Waste in order to recover energy from it. These technologies are Mass Burn Incineration with energy recovery, Mechanical Biological Treatment via bio-drying and Mechanical Heat Treatment, which is a relatively new and uninvestigated method, compared to the other two. Mechanical Biological Treatment and Mechanical Heat Treatment can turn Municipal Solid Waste into Solid Recovered Fuel that could be combusted for energy production or replace other fuels in various industrial processes. The analysis showed that performance of these two technologies depends strongly on the final use of the produced fuel and they could produce GHG emissions savings only when there is end market for the fuel. On the other hand Mass Burn Incineration generates greenhouse gas emission savings when it recovers electricity and heat. Moreover the study found that the expected increase on the amount of Municipal Solid Waste treated for energy recovery in England by 2020 could save greenhouse gas emission, if certain Energy from Waste technologies would be applied, under certain conditions.     

有色金属行业CO2排放估算方法研究

通过对国内外有色金属行业温室气体排放估算方法研究现状的分析,将联合国政府间气候变化专门委员会(IPCC)温室气体排放清单指南、国际有色行业协会和环境科学研究中的一些常用算法,总结归纳应用于有色金属行业温室气体的排放量估算,从估算方法和结果上分析各种方法的优缺点和使用条件。以原铝生产CO2排放估算为例,对有色金属温室气体排放进行实证分析,为有色金属行业温室气体排放估算提供参选方法,促进有色金属工业的节能减排。     

Environmental and economic impact assessment of construction and demolition waste disposal using system dynamics

Construction and demolition wastes (CDW) have increasingly serious problems in environmental, social, and economic realms. There is no coherent framework for utilization of these wastes which are disposed both legally and illegally. This harms the environment, contributes to the increase of energy consumption, and depletes finite landfills resources. The aim of this paper is to evaluate the impacts of two alternatives for the management of CDW, recycling and disposing. The evaluation is carried out through developing a dynamic model with aid STELLA software by conducting the following steps: (1) quantifying the total cost incurred to mitigate the impacts of CDW landfills and uncollected waste on the environment and human health; (2) quantifying the total avoided emissions and saved energy by recycling waste; (3) estimating total external cost saved by recycling waste and; (4) providing a decision support tool that helps in re-thinking about waste disposal. The proposed evaluation methodology allows activating the stringent regulations that restrict waste disposal and developing incentives to encourage constructors to recycle their wastes. The research findings show that recycling CDW leads to significant reductions in emissions, energy use, global warming potential (GWP), and conserves landfills space when compared to disposal of wastes in landfills. Furthermore, the cost of mitigating the impact of disposal is extremely high. Therefore, it is necessary to recycle construction and demolition wastes.     

有色金属行业CO2排放估算方法研究

通过对国内外有色金属行业温室气体排放估算方法研究现状的分析，将联合国政府间气候变化专门委员会（IPCC）温室气体排放清单指南、国际有色行业协会和环境科学研究中的一些常用算法，总结归纳应用于有色金属行业温室气体的排放量估算，从估算方法和结果上分析各种方法的优缺点和使用条件。以原铝生产CO2排放估算为例，对有色金属温室气体排放进行实证分析，为有色金属行业温室气体排放估算提供参选方法，促进有色金属工业的节能减排。     

我国炼化企业温室气体减排及CDM项目开展情况分析

我国炼化企业是高耗能高污染企业,温室气体排放量大而分散,减排潜力巨大。目前我国炼化企业比较重视废气的治理,如SOx,对于温室气体减排工作的研究投入力度相对较小,CDM项目很少且主要集中于N2O减排CDM项目。考虑到第一承诺期结束以后我国可能需要承担减排任务,单纯N2O减排将不能满足我国的温室气体减排需求。因此,我国炼化企业需要开展CO2减排技术研究。同时从节能减排及CO2资源化利用等方面对我国炼化企业进行分析,提出我国炼化企业节能减排措施,为我国炼化企业CO2减排提供理论依据。     

Mitigation paths for Chinese iron and steel industry to tackle global climate change

Based on a recognition of the essence of climate change and the pressure on China to reduce its greenhouse gas (GHG) emissions, this paper interprets the important role that the Chinese iron and steel industry may play in managing emissions. Through an investigation of the key sources of GHG emissions in the Chinese iron and steel industry, a comparison of the current Chinese and international situations, and a survey of the technology and methods available for reducing GHG emissions, and their application in China, the authors analyze the major issues currently faced by the Chinese iron and steel industry, and propose the following four approaches through which the industry might reduce its GHG emissions: (1) encouragement of clean development mechanism (CDM) projects, mainly involving secondary energy reuse, to provide capital and technology for GHG reduction activities in China; (2) stimulation of the social responsibility-based voluntary carbon market (VCM) to increase the long-term benefits for the Chinese iron and steel industry from emission reductions; (3) undertaking of strict energy auditing to help enterprises establish appropriate emission reduction targets and formulate reasonable plans; (4) promotion of emission reduction-oriented investment within the industry to obtain profits from project operation, while at the same time gaining extra compensation for emission reductions. More specifically, the design of each of these approaches should take into consideration the related economic factors and incentive mechanisms.     

Meeting the climate change challenge: a scan of greenhouse gas emissions in BC communities

The Canadian province of British Columbia (BC) is taking significant steps towards climate change mitigation, including a carbon tax on fossil fuels and legislation that mandates greenhouse gas (GHG) reductions within public sector organisations and GHG reduction targets for municipalities. This paper carries out a preliminary scan of the GHG emissions of BC communities using the provincially mandated Community Energy and Emissions Inventory reports. We map trends in energy consumption and emissions per capita while uncovering correlations between these variables and land-use planning, geographic, and demographic variables. These data have shown that: (1) energy consumption in BC is an adequate proxy for GHG emissions; (2) transportation, more than buildings, is a strong driver of overall GHG emissions; (3) building emissions are not likely to be strongly influenced by dwelling type, but density of buildings is crucial; (4) geographic location influences emissions; and (5) population size and age do not appear to influence per capita emissions. These findings are particularly important as they suggest that the potentially intransigent factors of income and population size need not be barriers to achieving significant GHG reductions. The policy onus thus falls squarely on transportation planning, land-use, energy conservation, and fuel switching. This in turn highlights the importance of deeper underlying sociocultural and political preferences, which shape the behaviours that have a strong bearing on emissions profiles.     

Spaghetti soup: The complex world of food waste behaviours

There is growing awareness of the positive impact of reducing the amount of wasted food on greenhouse gas emissions, energy use, food and water security, and land use. In developed nations, food waste generated in homes is a large contributor to the total amount of food waste. The behaviours and practices associated with this waste prevention (and waste generation) are complex for a number of reasons: food waste is the result of multiple, interacting activities and this leads to separation between the activity and their consequences. These behaviours are usually performed for reasons unrelated to waste prevention and have both a marked habitual element and a pronounced emotional component. Furthermore, the prevention of food waste has less ‘visibility’ to other people (e.g. neighbours) than many other pro-environmental behaviours (e.g. recycling), and therefore social norms around ‘waste’ play a reduced role compared to more ‘visible’ activities.This paper discusses insights into these behaviours from research funded by the Waste & Resources Action Programme (WRAP) and its partners in the UK. It discusses how these insights have been used in the development of a successful public-engagement campaign, which has been influential in the recent reduction in household food waste. These insights are also discussed in light of commonly used behavioural models, highlighting that many of these models are not designed for multiple, complex behaviours. However, considering the subject of food waste through the ‘lenses’ of different academic disciplines has helped the development of the public engagement on this issue.     

Estimating the potential of greenhouse gas mitigation in Kazakhstan

As part of the studies related to the obligations of the UN Framework Convention on Climate Change, the Republic of Kazakhstan started activities to inventory greenhouse gas (GHG) emissions and assess of GHG mitigation options. The objective of this paper is to present an estimate of the possibility of mitigating GHG emissions and determine the mitigation priorities. It presents a compilation of the possible options and their assessment in terms of major criteria and implementation feasibility. Taking into account the structure of GHG emissions in Kazakhstan in 1990, preliminary estimates of the potential for mitigation are presented for eight options for the energy sector and agriculture and forestry sector. The reference scenario prepared by expert assessments assumes a reduction of CO₂ emissions in 1996–1998 by about 26% from the 1990 level due to general economic decline, but then emissions increase. It is estimated that the total potential for the mitigation of CO₂ emissions for the year 2000 is 3% of the CO₂ emissions in the reference scenario. The annual reduction in methane emissions due to the estimated options can amount to 5%–6% of the 1990 level.

     

Life cycle analysis of silane recycling in amorphous silicon-based solar photovoltaic manufacturing

Amorphous silicon (a-Si:H)-based solar cells have the lowest ecological impact of photovoltaic (PV) materials. In order to continue to improve the environmental performance of PV manufacturing using proposed industrial symbiosis techniques, this paper performs a life cycle analysis (LCA) on both conventional 1-GW scaled a-Si:H-based single junction and a-Si:H/microcrystalline-Si:H tandem cell solar PV manufacturing plants and such plants coupled to silane recycling plants. Both the energy consumed and greenhouse gas emissions are tracked in the LCA, then silane gas is reused in the manufacturing process rather than standard waste combustion. Using a recycling process that results in a silane loss of only 17% instead of conventional processing that loses 85% silane, results in an energy savings of 81,700 GJ and prevents 4400 tons of CO₂ from being released into the atmosphere per year for the single junction plant. Due to the increased use of silane for the relatively thick microcrystalline-Si:H layers in the tandem junction plants, the savings are even more substantial – 290,000 GJ of energy savings and 15.6 million kg of CO₂ eq. emission reductions per year. This recycling process reduces the cost of raw silane by 68%, or approximately $22.6 million per year for a 1-GW a-Si:H-based PV production facility and over $79 million per year for tandem manufacturing. The results are discussed and conclusions are drawn about the technical feasibility and environmental benefits of silane recycling in an eco-industrial park centered around a-Si:H-based PV manufacturing plants.     

云南省城市生活垃圾处理温室气体排放特征

根据《IPCC国家温室气体清单指南》和《省级温室气体清单编制指南》方法,建立2018年云南省16个州(市)城市生活垃圾处理温室气体排放清单,包括生活垃圾填埋和焚烧处理过程,并分析了温室气体排放的时间分布、空间分布和影响因素等。结果表明;(1)2018年云南省生活垃圾处理温室气体总排放量为536万t CO_2当量,各州(市)间排放量差异明显,滇中经济发达地区和滇东北人口密度较高地区排放量明显高于滇西北地区。(2)2005—2018年,云南省生活垃圾处理排放的温室气体量增长了191.3%,温室气体排放组成发生明显变化,CH4比重不断下降,CO_2比重不断增加。(3)城镇人口数量、生活垃圾处理量、经济发展水平与温室气体排放量显著相关,其中人口数量更为明显。     

深圳市南山区碳平衡测算研究

运用《省级温室气体清单编制指南》、《IPCC国家温室气体清单指南》和相关文献推荐方法,利用南山区能源消费数据、工业产品量、废弃物处理量、森林面积和海洋面积等基础数据,对南山区能源利用过程、工业生产过程和产品使用、废弃物处理等3大类碳源温室气体排放量以及区域森林(包括湿地)、城市绿地和海域等3大类碳汇储存量进行了测算,计算表明南山区年碳排放总量达到756.17万t,该测算为南山区未来区域碳减排提供基础数据依据。     

From the LCA of food products to the environmental assessment of protected crops districts: a case-study in the south of Italy

In the present study, Life Cycle Assessment (LCA) methodology was applied to evaluate the energy consumption and environmental burdens associated with the production of protected crops in an agricultural district in the Mediterranean region. In this study, LCA was used as a 'support tool', to address local policies for sustainable production and consumption patterns, and to create a 'knowledge base' for environmental assessment of an extended agricultural production area. The proposed approach combines organisation-specific tools, such as Environmental Management Systems and Environmental Product Declarations, with the environmental management of the district. Questionnaires were distributed to producers to determine the life cycle of different protected crops (tomatoes, cherry tomatoes, peppers, melons and zucchinis), and obtain information on greenhouse usage (e.g. tunnel vs. pavilion). Ecoprofiles of products in the district were also estimated, to identify supply chain elements with the highest impact in terms of global energy requirements, greenhouse gas emissions, eutrophication, water consumption and waste production. These results of this study enable selection of the 'best practices' and ecodesign solutions, to reduce the environmental impact of these products. Finally, sensitivity analysis of key LCA issues was performed, to assess the variability associated with different parameters: vegetable production; water usage; fertiliser and pesticide usage; shared greenhouse use; substitution of plastics coverings; and waste recycling.     

Environmental assessment of different management options for individual waste fractions by means of life-cycle assessment modelling

Several alternatives exist for handling of individual waste fractions, including recycling, incineration and landfilling. From an environmental point of view, the latter is commonly considered as the least desirable option. Many studies based on life-cycle assessment (LCA) highlight the environmental benefits offered by incineration and especially by recycling. However, the landfilling option is often approached unjustly in these studies, maybe disregarding the remarkable technological improvements that landfills have undergone in the last decades in many parts of the world.This study, by means of LCA-modelling, aims at comparing the environmental performance of three major management options (landfilling, recycling and incineration or composting) for a number of individual waste fractions. The landfilling option is here approached comprehensively, accounting for all technical and environmental factors involved, including energy generation from landfill gas and storage of biogenic carbon. Leachate and gas emissions associated to each individual waste fraction have been estimated by means of a mathematical modelling. This approach towards landfilling emissions allows for a more precise quantification of the landfill impacts when comparing management options for selected waste fractions.Results from the life-cycle impact assessment (LCIA) show that the environmental performance estimated for landfilling with energy recovery of the fractions “organics” and “recyclable paper” is comparable with composting (for “organics”) and incineration (for “recyclable paper”). This however requires high degree of control over gas and leachate emissions, high gas collection efficiency and extensive gas utilization at the landfill. For the other waste fractions, recycling and incineration are favourable, although specific emissions of a variety of toxic compounds (VOCs, PAHs, NO_x, heavy metals, etc.) may significantly worsen their environmental performance.     

采油作业区节能减排探索与实践

H作业区经过对节能减排中问题的总结,实施了哈得四联合站放空气回收轻烃外输、哈得一联合站二段气回收、污水闭路循环回收利用、淡化水流程优化等节能减排工程,促进了节能减排,减少了碳排放,实现了清洁生产,取得了较好的经济效益和环境效益。     

Reducing climate change gas emissions by cutting out stages in the life cycle of office paper

The paper industry's climate change gas emissions are growing. This article considers how to reduce emissions from cut-size office paper by bypassing stages in its life cycle. The options considered are: incineration, which cuts out landfill; localisation, which cuts out transport; annual fibre, which cuts out forestry and reduces pulping; fibre recycling, which cuts out landfill, forestry and pulping; un-printing, which cuts out all stages except printing; electronic-paper, which cuts out all stages. Un-printing may offer the greatest climate change emission reduction. There are uncertainties in this result, particularly in estimating the proportion of waste office paper would be suitable for un-printing.     

Greenhouse gas emissions in Canada and Japan: sector-specific estimates and managerial and economic implications

Many firms generate large amounts of carbon dioxide and other greenhouse gases when they burn fossil fuels in their production processes. In addition, production of raw materials and other inputs the firms procure for their operations also generates greenhouse gases indirectly. These direct and indirect greenhouse gas emissions occur in many sectors of our economies. In this paper, we first present sector-specific estimates for such greenhouse gas emissions. We then show that estimates for such sector-specific greenhouse gas emissions are often required for various types of corporate as well as public policy analyses in both domestic and international contexts. Measuring greenhouse gas emissions resulting from firms' multi-stage production processes in a multi-sector context is relevant for policies related to the Kyoto protocol, an international agreement to limit global greenhouse gas emissions. For example, since the protocol allows firms to engage in trading and offsetting of their greenhouse gas emissions across national borders, provided that emissions are correctly measured, the firms can take advantage of such trading schemes by placing their energy-intensive production facilities globally and strategically. We present several case studies which illustrate the importance of this and other aspects of greenhouse gas emissions in firms' environmental management. We also argue that our modeling and estimation methods based on input-output analyses are suitable for the types of research goals we have in this paper. Our methods are applied to data for Canada and Japan in a variety of environmental management circumstances.