Life Cycle Assessment of fossil energy use and greenhouse gas emissions in Chinese pear production

A Life Cycle Assessment (LCA) was performed to analyze environmental consequences of different pear production chains in terms of fossil energy use and greenhouse gas (GHG) emission in China. The assessment identified hotspots that contributed significantly to the environmental impacts of pear production from the cradle to the point of sale. The results showed that GHG emissions and fossil energy use varied in the different production chains because the environmental performance does not associate with the farming systems (i.e. organic vs. conventional), but is co-determined by farm topography and thus machinery use, by market demands to seasonality of products and thus the need for storage, and by local farming practices including manure management. The LCA could be used as a tool to guide selections of agricultural inputs with the aim of reducing environmental impacts. The results of the LCA analysis indicate that a list of choices are available to reduce energy use and GHG emission in the pear production chain, namely substitution of the traditional storage systems by an efficiently controlled atmosphere storage system, using manure for biogas production, conversion from the conventional farming to organic farming, and reduction of mechanical cultivation.     

A comparative study on milk packaging using life cycle assessment: from PA-PE-Al laminate and polyethylene in China

A Life Cycle Assessment (LCA) approach was used to compare the environmental impacts in the life cycle of two milk packaging systems, PA-PE-Al laminate—a laminated foil made from paper, polyethylene and aluminum foil—and polyethylene. The data for the mass, energy fluxes and environmental emissions were obtained from published literature and from site investigations, for the two systems being analyzed for environmental impacts. The application of LCA using Eco-Indicator 99 has made the comparison of the environmental impacts of the two milk packages possible. The results of this LCA study are discussed and the results reveal that the composite packaging has a slightly higher environmental impact than the plastic one. In addition, the environmental impact of raw material extraction is the highest in all of the life cycle stages except for disposal. The environmental impact of composite packaging mainly comes from the fossil fuels, land use and respiratory inorganics categories, while the plastic packaging mainly comes from the fossil fuels category. However, the composite packaging has a greater environmental impact because it has not been well recycled and reused. This environmental impact could be decreased by developing the technology to separate out polyethylene and aluminum from the packaging.     

LCA of comprehensive pig manure management incorporating integrated technology systems

Increased and intensified pig production has raised the needs for proper management systems of pig manure in order to reduce negative environmental impacts. The objectives of this study were to identify the most significant environmental impacts from pig manure management considering a wide range of impact categories and to determine which integrated technology system at which handling stage can achieve the highest impact reduction. Twelve scenarios applying various treatment, storage and land application systems were developed and compared. Life cycle assessment (LCA) with the aim of capturing the actual consequences of the considered scenarios was selected as the tool for impact quantification. The most important impact categories in this investigation are global warming (GWP), aquatic eutrophication (AEP), respiratory inorganics (RIP), and terrestrial eutrophication (TEP). The two latter impacts, caused by ammonia emissions, have not been widely considered in most of previous LCA studies on pig manure management. The main keys for the effective impact reduction are the integration of treatment technology systems aiming at energy recovery with high nutrient recovery and control of greenhouse gas, ammonia, and nitrate emissions at every handling stage. For GWP and AEP, the anaerobic digestion-based scenario with natural crust storage achieves the highest impact reduction because of high efficiencies in energy and nutrient recovery with restricted emissions of GHG and nitrate. For RIP and TEP, the incineration and thermal gasification based scenarios and the scenario without a treatment system applying the deep injection method yield the highest impact minimisation due to the lowest ammonia emissions. This study further indicates the need to consider all significant impacts to decide the best management options taking into consideration local conditions.     

Livestock-related greenhouse gas emissions: impacts and options for policy makers

Research shows that livestock account for a significant proportion of greenhouse gas (GHG) emissions and global consumption of livestock products is growing rapidly. This paper reviews the life cycle analysis (LCA) approach to quantifying these emissions and argues that, given the dynamic complexity of our food system, it offers a limited understanding of livestock's GHG impacts. It is argued that LCA's conclusions need rather to be considered within a broader conceptual framework that incorporates three key additional perspectives. The first is an understanding of the indirect second order effects of livestock production on land use change and associated CO₂ emissions. The second compares the opportunity cost of using land and resources to rear animals with their use for other food or non-food purposes. The third perspective is need—the paper considers how far people need livestock products at all. These perspectives are used as lenses through which to explore both the impacts of livestock production and the mitigation approaches that are being proposed. The discussion is then broadened to consider whether it is possible to substantially reduce livestock emissions through technological measures alone, or whether reductions in livestock consumption will additionally be required. The paper argues for policy strategies that explicitly combine GHG mitigation with measures to improve food security and concludes with suggestions for further research.     

Life cycle assessment of sunflower and rapeseed as energy crops under Chilean conditions

An option for the agriculture and energy sectors in Chile is the cultivation of energy crops, but environmental studies are first needed in the framework of a sustainable national energy policy.In this study, we used a cradle-to-farm gate Life Cycle Assessment (LCA) to compare environmental impacts and energy and water demand of rapeseed (Brassica napus L.) and sunflower (Helianthus annuus L.) in Chile, as potential oleaginous crops for first-generation biodiesel production. National agricultural data are used for the LCA inventory and process data of international databases are adapted to local conditions. The effect of field N₂O emissions and land use change is evaluated. The results indicate that, compared to sunflower, rapeseed production has a better environmental performance in 9 out of the 11 impact categories evaluated, and lower water consumption. The energy demand of rapeseed is 4.9 GJ/t seed, 30% less than that of sunflower. Mineral fertilizers cause the highest environmental impact in both crops. The analysis of the life cycle of fertilizers indicates that extraction of raw materials and its production are key stages. Attempts to reduce the environmental impact and energy requirement of both crops should be mainly associated with the evaluation of other types of fertilization. In addition, particularly for sunflower, low impact herbicides should be evaluated, seed yield improved and cultivation practices optimized. If the crops are produced on degraded grasslands, the greenhouse gas emissions may be reduced.     

Positive and negative feedback in consequential life-cycle assessment

In this paper we develop a typology of consequences that can be used for environmental assessments of investment in technologies. As an illustration we estimate how the inclusion of different cause–effect chains could affect the estimated greenhouse gas emissions resulting from buying and using a fuel cell bus today. In contrast to earlier studies, we include cause–effect chains containing positive feedback from adoption (e.g. economies of scale and learning). We discuss how our findings affect the usefulness and limitations of consequential life-cycle assessment (LCA) and how LCA methodology in more general can be used to support strategic technology choice. A major conclusion is that environmental assessments of investment in emerging technologies should not only include effects resulting from marginal change of the current system but also marginal contributions to radical system change.     

Life cycle assessment of ACQ-treated lumber with comparison to wood plastic composite decking

A cradle-to-grave life cycle assessment was done to identify the environmental impacts related to alkaline copper quaternary (ACQ)-treated lumber used for decking and to determine how the impacts compare to the primary alternative product, wood plastic composite (WPC) decking. A model of ACQ-treated lumber life cycle stages was created and used to calculate inputs and outputs during the lumber production, treating, use, and disposal stages. Lumber production data are based on published sources. Primary wood preservative treatment data were obtained by surveying wood treatment facilities in the United States. Product use and disposal inventory data are based on published data and professional judgment. Life cycle inventory inputs, outputs, and impact indicators for ACQ-treated lumber were quantified using functional units of 1000 board feet and per representative deck (assumed to be 320 square feet (30 square meters) of surface decking material) per year of use. In a similar manner, an inventory model was developed for the manufacture, use, and disposal of the primary alternative product, WPC. Impact indicator values, including greenhouse gas (GHG) emissions, fossil fuel use, water use, acidification, smog forming potential, ecological toxicity, and eutrophication were quantified for each of the two decking products. National normalization was done to compare the significance of a representative deck surface per year of use to a family’s total annual impact footprint.If an average U.S. family adds or replaces a deck surfaced with ACQ-treated lumber, their impact “footprint” for GHG emissions, fossil fuel use, acidification, smog forming potential, ecological toxicity, and eutrophication releases each is less than one-tenth of a percent of the family’s annual impact. ACQ-treated lumber impacts were fourteen times less for fossil fuel use, almost three times less for GHG emissions, potential smog emissions, and water use, four times less for acidification, and almost half for ecological toxicity than those for WPC decking. Impacts were approximately equal for eutrophication.     

纸塑铝复合包装处置方式的生命周期评价

采用生命周期评价(LCA)法研究了纸塑铝复合包装的全生命周期环境影响,并在处置阶段对不同处置方式的环境影响进行评价. 通过现场和资料调研的方式,获得所有生命周期阶段能量物质的输入/输出和环境外排数据. 结果表明:纸塑铝复合包装生命周期阶段中环境影响比重最大的是原料获取阶段,占75%以上. 纸塑铝复合包装的全生命周期环境影响主要集中在化石燃料、土地占用和无机物对人体损害3个方面,在矿产资源、气候变化、酸化富营养化和生态毒性方面影响稍小. 3种处置方式对环境影响由大到小依次为填埋＞焚烧＞再生,其中填埋和焚烧处置分别比纸塑铝复合包装处置阶段前的环境影响增加11%和7%,再生可降低23%,而进一步降低环境影响的方式为发展铝塑分离技术.      

基于生命周期视角的种养一体化奶牛场环境经济效益评估

准确评估种养一体化奶牛场的经济性能与环境绩效,是相关支持政策制定的基础,也是促进奶业低碳生产的关键.本文基于生命周期视角,对非种养一体化奶牛场（non-IPBS）和种养一体化奶牛场（IPBS）养殖过程中的温室气体排放、能源消耗、水消耗、土地占用等环境成本和经济效益进行评估.结果表明,non-IPBS生产1t标准牛奶（FPCM）的净收益为1427元,而IPBS的实际净收益提高7%,如果青贮玉米自给率从当前的32%提升到100%,则实际净收益将提高19%,同时,该净收益的提高率取决于耕地流转费用,临界点为14695元/hm²;相比non-IPBS,IPBS生产1tFPCM的温室气体排放、能源消耗、水消耗、土地占用分别减少6%、6%、5%、7%,如果青贮玉米自给率提升到100%,则相应减少16%、16%、11%、14%.IPBS在降低青贮玉米种植的化肥施用、解决养殖场粪便污染等方面优势明显,在提升养殖经济效益、降低温室气体排放等方面具有巨大潜力,值得推广.     

食用油聚酯包装的生命周期评价

采用生命周期评价法研究了食用油聚酯(PET)包装的生命周期环境影响,并对不同处置方式的环境影响进行比较评价. 通过现场和资料调研的方式获得所有生命周期阶段的能量物质的输入、输出和环境外排数据. 结果表明:PET包装原料获取阶段的环境影响潜值在全生命周期环境影响潜值中所占比例极高,占处置前环境影响潜值的81.8%. PET包装的全生命周期环境影响类别主要集中在化石燃料、无机物对人体损害和气候变化3个方面;在致癌、生态毒性和酸化/富营养化等方面的影响较小. 3种主要处置方式的环境影响潜值为焚烧＞填埋＞再生,其中焚烧和填埋分别增加PET包装处置阶段前环境影响潜值的5.1%和3.6%,而再生可降低63.9%.      

Life cycle assessment of hydrotreated vegetable oil from rape,oil palm and Jatropha

A life cycle assessment of hydrotreated vegetable oil (HVO) biofuel was performed. The study was commissioned by Volvo Technology Corporation and Volvo Penta Corporation as part of an effort to gain a better understanding of the environmental impact of potential future biobased liquid fuels for cars and trucks. The life cycle includes production of vegetable oil from rape, oil palm or Jatropha, transport of the oil to the production site, production of the HVO from the oil, and combustion of the HVO. The functional unit of the study is 1 kWh energy out from the engine of a heavy-duty truck and the environmental impact categories that are considered are global warming potential (GWP), acidification potential (AP), eutrophication potential (EP) and embedded fossil production energy. System expansion was used to take into account byproducts from activities in the systems; this choice was made partly to make this study comparable to results reported by other studies. The results show that HVO produced from palm oil combined with energy production from biogas produced from the palm oil mill effluent has the lowest environmental impact of the feedstocks investigated in this report. HVO has a significantly lower life cycle GWP than conventional diesel oil for all feedstocks investigated, and a GWP that is comparable to results for e.g. rape methyl ester reported in the literature. The results show that emissions from soil caused by microbial activities and leakage are the largest contributors to most environmental impact categories, which is supported also by other studies. Nitrous oxide emissions from soil account for more than half of the GWP of HVO. Nitrogen oxides and ammonia emissions from soil cause almost all of the life cycle EP of HVO and contribute significantly to the AP as well. The embedded fossil production energy was shown to be similar to results for e.g. rape methyl ester from other studies. A sensitivity analysis shows that variations in crop yield and in nitrous oxide emissions from microbial activities in soil can cause significant changes to the results.     

Life cycle assessment of borate-treated lumber with comparison to galvanized steel framing

A cradle-to-grave life cycle assessment was done to identify the environmental impacts related to borate-treated lumber used as structural framing and to determine how the impacts compare to the primary alternative product, galvanized steel framing members. Borate-treated lumber may be used for framing buildings in locations of high decay or termite hazard. A model of borate-treated lumber life cycle stages was created and used to calculate inputs and outputs during the lumber production, treating, use, and disposal stages. Lumber production data are based on published sources. Primary wood preservative treatment data were obtained by surveying wood treatment facilities in the United States. Product use and disposal inventory data are based on published data and professional judgment. Life cycle inputs, outputs, and impact indicators for borate-treated lumber were quantified using life cycle assessment LCA methodologies at functional units of 1000 board feet, 100 linear feet (30.5 linear meters) of structural perimeter wall framing, and framing required for the perimeter walls of one representative home. In a similar manner, a life cycle inventory model was developed for the manufacture, use, and disposal of the primary alternative product, galvanized steel framing, and comparisons were done using an equivalent measure of 100 linear feet of structural perimeter wall framing. Impact indicator values such as greenhouse gas (GHG) emissions, fossil fuel use, water use, acidification, ecological toxicity, smog forming potential, and eutrophication were quantified for each of the two framing products.National normalization was done to compare the significance of the framing in a representative U.S. family home to the family’s total annual impact footprint.If a U.S. family of three builds a 2225 square feet (207 square meters) home using borate-treated lumber for structural perimeter wall framing, the framing impact “footprint” (normalized over the use life of the structure) for GHG emissions, fossil fuel use, acidification, ecological toxicity, smog forming potential, and eutrophication each is less than one-tenth of a percent of the family’s annual overall impact. The cradle-to-grave life cycle impacts of borate-treated lumber framing were approximately four times less for fossil fuel use, 1.8 times less for GHGs, 83 times less for water use, 3.5 times less for acidification, 2.5 times less for ecological impact, 2.8 times less for smog formation, and 3.3 times less for eutrophication than those for galvanized steel framing.     

Assessing the environmental impact of metal production processes

Evaluating both new and existing processes for primary metal production to assess their environmental impacts is often difficult due to the many inputs and outputs involved. Life Cycle Assessment (LCA) is a methodology that can be used for such purposes to identify those parts of the metal production life cycle that have significant environmental impacts. LCA has been used by CSIRO Minerals to assess the “cradle-to-gate” environmental impacts of a number of metal production processes practised either currently or potentially in Australia. The metals considered included copper, nickel, aluminium, lead, zinc, steel, stainless steel and titanium, by both pyrometallurgical and hydrometallurgical routes in some instances. The environmental profile included greenhouse and acid rain gas emissions, solid waste emissions and gross energy consumption. The results for various metals are compared in this paper. New process technologies for primary metal production can be expected to reduce the environmental impacts of metal production, and estimates of likely reductions for technologies involving stainless steel, titanium and aluminium are also presented in this paper.     

Global warming contributions from wheat,sheep meat and wool production in Victoria,Australia – a life cycle assessment

This paper compares the life cycle global warming potential of three of Australia’s important agricultural production activities – the production of wheat, meat and wool in grazed subterranean clover (sub-clover) dominant pasture and mixed pasture (perennial ryegrass/phalaris/sub-clover/grass and cape weed) systems. Two major stages are presented in this life cycle assessment (LCA) analysis: pre-farm, and on-farm. The pre-farm stage includes greenhouse gas (GHG) emissions from agricultural machinery, fertilizer, and pesticide production and the emissions from the transportation of these inputs to paddock. The on-farm stage includes GHG emissions due to diesel use in on-farm transport and processing (e.g. seeding, spraying, harvesting, topdressing, sheep shearing), and non-CO₂ (nitrous oxide (N₂O), and methane (CH₄)) emissions from pastures and crop grazing of lambs.The functional unit of this life cycle analysis is the GHG emissions (carbon dioxide equivalents – CO₂ -e) from 1 kg of wheat, sheep meat and wool produced from sub-clover, wheat and mixed pasture plots. The GHG emissions (e.g. CO₂, N₂O and CH₄ emission) from the production, transportation and use of inputs (e.g. fertilizer, pesticide, farm machinery operation) during pre-farm and on-farm stages are also included. The life cycle GHG emissions of 1 kg of wool is significantly higher than that of wheat and sheep meat. The LCA analysis identified that the on-farm stage contributed the most significant portion of total GHG emissions from the production of wheat, sheep meat and wool. This LCA analysis also identified that CH₄ emissions from enteric methane production and from the decomposition of manure accounted for a significant portion of the total emissions from sub-clover and mixed pasture production, whilst N₂O emissions from the soil have been found to be the major source of GHG emissions from wheat production.     

生命周期视角下废弃餐饮油脂炼制生物柴油的环境效益分析

废弃餐饮油脂的资源化利用是关乎公众健康和环境保护的重要举措.目前我国废弃餐饮油脂炼制生物柴油的环境效益尚不明晰、国家政策模糊,相关产业发展滞缓.本研究以国内废弃餐饮油脂炼制生物柴油的典型企业为例,利用GaBi软件对废弃餐饮油脂的收集、预处理、酯化和运输等过程全生命周期阶段的资源环境影响进行系统核算,评估其环境效益,以期为国家生物柴油行业发展和相关政策制定提供科学依据.研究结果表明:①整个生命周期过程中,酯化阶段的环境影响最大,各指标占比为52.91%～96.05%,其环境影响主要是由燃煤、用电和甲醇消耗引起;②敏感性分析结果显示,燃煤、用电、甲醇消耗和收集距离的变化对整个生命周期环境影响结果有着较大影响;③废弃餐饮油脂炼制的生物柴油生命周期化石能源消耗16406 MJ·t~(-1)、温室气体排放815 kg CO_2 eq·t~(-1),与石化柴油相比,具有较好的节能和温室气体减排效益.     

生命周期评价应用于温室气体排放的研究进展

致使全球气候变暖的温室气体排放问题已经全面引起了人们的广泛关注。生命周期评价作为一种评价环境负荷的评价工具,用于科学定量地估算产品、服务及工艺流程改造等方面的温室气体排放有其独特的优势。文章介绍了估算温室气体排放简化生命周期的技术框架及生命周期评价方法在第一产业(种植业、畜牧业),第二产业(硬纸板加工、橡胶生产、废塑料燃烧的能源再利用)以及第三产业(交通运输、旅游业)的应用情况,并综述了三个产业中的主要系统边界划分原则以及对温室气体排放影响的主要因素;同时,介绍了我国在节能减排方面利用生命周期评价方法的研究与应用实例。     

Greenhouse gas emissions from production and use of used cooking oil methyl ester as transport fuel in Thailand

Biodiesel, produced from various vegetable and/or animal oils, is one of the most promising alternative fuels for transportation in Thailand. Currently, the waste oils after use in cooking are not disposed adequately. Such oils could serve as a feedstock for biodiesel which would also address the waste disposal issue. This study compares the life cycle greenhouse gas (GHG) emissions from used cooking oil methyl ester (UCOME) and conventional diesel used in transport. The functional unit (FU) is 100 km transportation by light duty diesel vehicle (LDDV) under identical driving conditions. Life cycle GHG emissions from conventional diesel are about 32.57 kg CO₂-eq/FU whereas those from UCOME are 2.35 kg CO₂-eq/FU. The GHG emissions from the life cycle of UCOME are 93% less than those of conventional diesel production and use. Hence, a fuel switch from conventional diesel to UCOME will contribute greatly to a reduction in global warming potential. This will also support the Thai Government's policy to promote the use of indigenous and renewable sources for transportation fuels.     

Life cycle assessment as a decision support tool for landfill gas-to energy projects

The greenhouse gas (GHG) emissions from MSW landfill, and control methods to eliminate or minimize these impacts including energy recovery from landfill gas (LFG) of MSW landfill in Thailand have been evaluated. Life Cycle Assessment (LCA) is used as the analytical tool to evaluate the environmental consequences of landfilling holistically. The economic implications of the control methods are also briefly assessed. The results show that in terms of GHG emissions as well as in terms of economics, it is more advantageous to have a large centralized landfill and produce electricity from the LFG rather than having several small, localized landfills despite significantly lower transportation requirement for the latter case. Sensitivity analysis revealed that the global warming potential was sensitive to gas collection efficiency as well as methane oxidation rate in the landfill. This study shows the utility of a life cycle approach for evaluating LFG-to-energy (LFGTE) projects.     

An assessment of greenhouse gas emissions and material flows caused by the Finnish economy using the ENVIMAT model

An environmentally extended input-output (EE-IO) analysis - environmental impacts of material flows caused by the Finnish economy - was carried out in order to improve data on production and consumption in Finland. The study resulted in the ENVIMAT model, which can be used to analyze the relationship between material flows, environmental impacts and the economy. The model is based on monetary and physical input-output tables and an environmental life-cycle impact assessment. This article summarizes the main methodological aspects and findings regarding the material flows and climate impacts caused by the Finnish economy in 2002 and 2005. The Finnish model has relatively detailed input data with 150 industries and 918 products and the data on imports was assessed according to a mixed approach with the help of life-cycle inventory data. The results of the model showed that the Finnish economy uses imported material resources as much as domestic resources. Life-cycle greenhouse gas (GHG) emissions caused by imports were equivalent to 70-80% of domestic emissions. The GHG emissions embodied in imports (emissions abroad) and exports (emissions within Finland) were of the same magnitude. The analysis showed that the service sector accounted for 44% of GHG emissions caused by the domestic final use of products. Analysis of the results also showed that the indicator of total material requirement (TMR) should not be used for environmental impact comparisons of products and services. In the future, the aim is to use the ENVIMAT model for assessing temporal changes in the economy; for monitoring sustainable development; for planning climate change mitigation; and for identifying important factors in the economy and assessing their impacts.     

Method for assessing impacts on life support functions (LSF) related to the use of ‘fertile land’ in Life Cycle Assessment (LCA)

Degradation of soil quality is a major concern due to the scarcity of fertile land, and needs to be properly addressed in the environmental assessment of agro-forestry systems. This paper addresses the main issues arising in assessing the impacts of fertile land use on “Life Support Functions” in Life Cycle Assessment (LCA). These issues include the assessment of occupation and transformation impacts, the references against which such impacts should be measured, and the concept of natural relaxation versus backup technology for recovery from the impacts. The alternative (or reference) situation is defined using the concept of consequential LCA, which facilitates clarification of the allocation issues arising due to successive land uses. This paper presents soil organic matter (SOM) as a robust indicator for soil quality; even though it does not fully consider all aspects of soil functioning, SOM has been often recognised as the best stand-alone indicator for soil quality. Impacts on biodiversity are not included in this indicator and should be assessed in parallel. Alternative data sources for practical implementation of the method are suggested in a hierarchical way, including locally specific data sets describing changes in SOM; mechanistic models for the prediction of SOM evolution; and general data sources for simplified analyses. Thanks to its flexibility in data collection the method is applicable to any agricultural or forestry LCA to fill an important gap in Life Cycle Impact Assessment (LCIA) of land use.