基于生命周期评价的瓦楞原纸产品碳足迹评价

依据PAS 2050:2011,采用B2B的方法利用eFootprint系统,对以废纸为原料生产的瓦楞原纸产品进行碳足迹评价.评价结果表明,生产1000 kg瓦楞原纸所排放的温室气体量为1226.79 kg CO2e,其中废纸制浆和抄纸过程是温室气体(GHG)主要排放过程,分别占GHG排放量的32.6％和54.1％;G...     

染整加工的碳足迹

全球变暖和碳足迹是目前非常热门的话题。气候变化对环境、居住地和地球造成的长期破坏性的影响,已引起人们很大的关注。大气温度的升高主要是由于温室气体(GHG,Green House Gases)的排放,包括二氧化碳(CO2)、甲烷、氧化亚氮(N2O)、氟碳化合物等。近年来,温室气体的排放呈指数级增长,引起了大气温度的升高。据报道,仅2010年温室气体排放就增长了6%,达到了5×1014吨,其中最主要的排放国家分别为中国、美国和印度。"碳足迹"是指个体、家庭、团体(公司)或产品(装置)在其     

生丝传统检验与电子检测的碳足迹核算与评价

为响应国家实现双碳目标,对生丝检验阶段进行了初级活动数据采集,并采用生命周期评价(LCA)方法对传统检验和电子检测2种检验过程中的碳足迹进行核算。结果表明：生丝传统检验方法和电子检测方法的碳足迹分别为0.235 5及0.233 6 kgCO₂e/kg,温室气体(GHG)排放主要来自恒温恒湿间的用电;单个检验项目中切断检验的GHG排放最高,外观检验次之,二者的GHG排放分别占传统检测方法的53.07%、36.88%;3个委托检验项目中茸毛检验的GHG排放最高,为0.014 5 kgCO₂e/kg,含胶率检验与单丝强伸度检验的排放均较低;不确定性分析表明每批丝的总质量对总排放的影响在3.95%以内(95%置信区间)。建立的生丝检验过程中初级活动数据的调研与分配方法,碳足迹核算以及不确定性分析的方法,可为丝绸行业进行碳足迹核算提供数据与方法参考。     

精纺羊毛织物工业碳足迹核算

依照现有的碳足迹核算方法,核算了从白毛条到精纺毛织物的工业碳足迹。结果显示高支纯毛面料在该阶段的碳足迹为7.31 kg CO2e/m布,其中电和蒸汽产生的碳足迹占比最大,超过85%。在毛条染色和纺纱阶段的碳足迹最大。除此之外,还计算出在各个阶段的碳足迹值:毛条生产过程碳足迹为4.54 kg CO2e/kg毛条,纺纱过程中的碳足迹为7.78 kg CO2e/kg纱线,织造过程中的碳足迹为0.08 kg CO2e/m布,后整阶段的碳足迹为2.53 kg CO2e/m布,包装阶段的碳足迹为0.27 kg CO2e/m布。结果对于后期的比较研究有所借鉴,且完善了羊毛产品碳足迹的研究。     

涤纶纺织品的碳足迹评估

根据BS EN ISO 14040:2006和PAS 2050:2008-商品和服务在生命周期内的温室气体排放评价规范,以及PAS 2050:2008规范使用指南,以100 kg涤纶长丝织物为功能单位,建立该功能单位从原油开采到完成印染加工这一系统边界的过程图;应用GaBi Education 4 LCA软件计算规定的系统边界内的碳足迹.数据分析表明,生产100 kg涤纶织物的碳排放量为2 570.10 kg CO2e,染整加工过程占总碳排放量的64.5％.     

香云纱面料碳足迹评价

介绍了传统纺织面料香云纱全生命周期内的碳足迹评价方法,包括各生产阶段温室气体的排放计算方法和依据。结果表明,1米黑色桑蚕丝香云纱面料的碳足迹为1.88 kg CO₂e,温室气体排放主要集中在蚕茧养殖到缫丝的原材料阶段。     

坯绸和丝绵产品的碳足迹核算与评价北大核心

为分析丝绸产品原料的碳足迹,对坯绸与丝绵产品生产过程的碳足迹进行核算与评价。结果表明:以鲜茧和干茧为原料生产的坯绸产品碳足迹分别为24.93 kgCO_(2)e/kg和27.84 kgCO_(2)e/kg,其中缫丝工序的碳足迹最大,分别约占两种坯绸产品碳足迹的47.39%和42.45%;丝绵产品从蚕茧入库到生产完成的碳足迹为10.14 kgCO_(2)e/kg,其中煮绵脱胶工序的碳足迹最大,约占丝绵产品碳足迹的39.63%;生产耗用的蒸汽为坯绸和丝绵产品碳足迹的最大排放源,在鲜茧缫丝坯绸、干茧缫丝坯绸与丝绵产品中分别约占61.72%、61.04%和79.06%。通过技术改进减少蒸汽耗用量、使用清洁电力、采购低碳双氧水等可有效降低坯绸和丝绵产品生产的碳足迹。     

服装销售环节的碳足迹评价研究

在服装全生命周期碳排放过程中,服装销售环节的碳排放问题不容忽视。文章详细描述了服装从出厂到消费者手中的销售环节,并从传统销售环节和网络销售环节2个方面阐述了温室效应气体(GHG)的排放源。在此基础上,主要探讨服装销售环节的碳足迹,通过绘制服装从出厂到消费者手中这一阶段的流程图、界定边界、收集数据等步骤来计算服装销售环节的碳足迹,并根据分析结果进行影响评价。对服装销售环节碳足迹的定量评价,促进减少温室气体的排放,有助于服装产业的可持续发展。     

纺织服装产品碳足迹核算中常用能源排放系数

合理的常用能源排放系数是纺织服装产品碳足迹核算中数据一致性的基础。参照PAS 2050,应用生命周期分析法(LCA)探讨了用于产品碳足迹的能源排放系数计算方法,通过实例计算、分析并评价了纺织服装产品碳足迹核算中常用能源的排放系数。结果表明,煤电排放系数适用于纺织服装产品碳足迹的核算;化石能源排放系数的间接温室气体排放均占总温室气体排放的5%以上。研究结论对完善产品碳足迹核算体系的构建具有理论和现实意义。     

不同包装方式对包装熟食米饭中碳足迹影响

气候变暖已成为全球面临的严重问题,各国均积极应对。食品体系产生大量温室气体,其碳足迹已成为研究热点。本研究依据产品碳足迹全生命周期评价标准,从单元操作角度计算不同包装（真空、空气和气调包装）操作工艺碳足迹。主要研究结论如下：包装200 g熟食米饭,在真空包装和空气包装条件下,最终碳足迹为：34.05±0.01 g CO2eq和57.94±0.01 g CO2eq。气调包装条件为40% O2+20% CO2+40% N2、50% O2+20% CO2+30% N2、60% O2+20% CO2+20% N2和70% O2+20% CO2+10% N2时,最终碳足迹分别为：214.39±0.26 g CO2eq,220.53±0.26 g CO2eq,224.76±0.55 g CO2eq和230.58±0.52 g CO2eq。研究发现使用塑料制品带来的碳排放在最终碳足迹中占较高比例,并且气调包装中使用气体产生的最终碳足迹占比较高。敏感性分析显示,包装过程中碳足迹对塑料制品排放因子是敏感的;空气及气调包装过程中碳足迹对设备排放因子变化以及电力使用效率变化是稳定的,而真空包装过程对两者敏感。可通过减少使用塑料制品,降低产品最终碳足迹。     

Uncertainty in life cycle greenhouse gas emissions from United States natural gas end-uses and its effects on policy

Increasing concerns about greenhouse gas (GHG) emissions in the United States have spurred interest in alternate low carbon fuel sources, such as natural gas. Life cycle assessment (LCA) methods can be used to estimate potential emissions reductions through the use of such fuels. Some recent policies have used the results of LCAs to encourage the use of low carbon fuels to meet future energy demands in the U.S., without, however, acknowledging and addressing the uncertainty and variability prevalent in LCA. Natural gas is a particularly interesting fuel since it can be used to meet various energy demands, for example, as a transportation fuel or in power generation. Estimating the magnitudes and likelihoods of achieving emissions reductions from competing end-uses of natural gas using LCA offers one way to examine optimal strategies of natural gas resource allocation, given that its availability is likely to be limited in the future. In this study, the uncertainty in life cycle GHG emissions of natural gas (domestic and imported) consumed in the U.S. was estimated using probabilistic modeling methods. Monte Carlo simulations are performed to obtain sample distributions representing life cycle GHG emissions from the use of 1 MJ of domestic natural gas and imported LNG. Life cycle GHG emissions per energy unit of average natural gas consumed in the U.S were found to range between -8 and 9% of the mean value of 66 g CO(2)e/MJ. The probabilities of achieving emissions reductions by using natural gas for transportation and power generation, as a substitute for incumbent fuels such as gasoline, diesel, and coal were estimated. The use of natural gas for power generation instead of coal was found to have the highest and most likely emissions reductions (almost a 100% probability of achieving reductions of 60 g CO(2)e/MJ of natural gas used), while there is a 10-35% probability of the emissions from natural gas being higher than the incumbent if it were used as a transportation fuel. This likelihood of an increase in GHG emissions is indicative of the potential failure of a climate policy targeting reductions in GHG emissions.     

Life cycle energy and greenhouse gas analysis of a large-scale vertically integrated organic dairy in the United States

In order to manage strategies to curb climate change, systemic benchmarking at a variety of production scales and methods is needed. This study is the first life cycle assessment (LCA) of a large-scale, vertically integrated organic dairy in the United States. Data collected at Aurora Organic Dairy farms and processing facilities were used to build a LCA model for benchmarking the greenhouse gas (GHG) emissions and energy consumption across the entire milk production system, from organic feed production to post-consumer waste disposal. Energy consumption and greenhouse gas emissions for the entire system (averaged over two years of analysis) were 18.3 MJ per liter of packaged fluid milk and 2.3 kg CO(2 )equiv per liter of packaged fluid milk, respectively. Methane emissions from enteric fermentation and manure management account for 27% of total system GHG emissions. Transportation represents 29% of the total system energy use and 15% of the total GHG emissions. Utilization of renewable energy at the farms, processing plant, and major transport legs could lead to a 16% reduction in system energy use and 6.4% less GHG emissions. Sensitivity and uncertainty analysis reveal that alternative meat coproduct allocation methods can lead to a 2.2% and 7.5% increase in overall system energy and GHG, respectively. Feed inventory data source can influence system energy use by -1% to +10% and GHG emission by -4.6% to +9.2%, and uncertainties in diffuse emission factors contribute -13% to +25% to GHG emission.     

麦草造纸碳足迹算法及低碳路径研究

探讨了麦草造纸业碳足迹及碳汇率计算方法;进而辅以国内典型规模与技术水平企业麦草产文化用纸生产线（40 t/d）为例,计算其碳汇率;最后提出提高我国麦草造纸碳汇率的路径。研究结果表明,造纸业碳足迹计算适用于生命周期法;我国典型企业麦草产漂白文化用纸线（40 t/d）的吨纸碳排放量的CO2为2 072.5 kg,碳汇率为0.78;企业须加大生产规模至80 t/d以上、采用节能高效先进生产工艺与装备降低碳排量,可实现麦草造纸碳汇率大于1.0。     

Life cycle assessment of a parabolic trough concentrating solar power plant and the impacts of key design alternatives

Climate change and water scarcity are important issues for today's power sector. To inform capacity expansion decisions, hybrid life cycle assessment is used to evaluate a reference design of a parabolic trough concentrating solar power (CSP) facility located in Daggett, CA, along four sustainability metrics: life cycle (LC) greenhouse gas (GHG) emissions, water consumption, cumulative energy demand (CED), and energy payback time (EPBT). This wet-cooled, 103 MW plant utilizes mined nitrates salts in its two-tank, thermal energy storage (TES) system. Design alternatives of dry-cooling, a thermocline TES, and synthetically derived nitrate salt are evaluated. During its LC, the reference CSP plant is estimated to emit 26 g of CO(2eq) per kWh, consume 4.7 L/kWh of water, and demand 0.40 MJ(eq)/kWh of energy, resulting in an EPBT of approximately 1 year. The dry-cooled alternative is estimated to reduce LC water consumption by 77% but increase LC GHG emissions and CED by 8%. Synthetic nitrate salts may increase LC GHG emissions by 52% compared to mined. Switching from two-tank to thermocline TES configuration reduces LC GHG emissions, most significantly for plants using synthetically derived nitrate salts. CSP can significantly reduce GHG emissions compared to fossil-fueled generation; however, dry-cooling may be required in many locations to minimize water consumption.     

Greenhouse gas emissions from milk production and consumption in the United States: A cradle-to-grave life cycle assessment circa 2008

This article presents a cradle-to-grave analysis of the United States fluid milk supply chain greenhouse gas (GHG) emissions that are accounted from fertilizer production through consumption and disposal of milk packaging. Crop production and on-farm GHG emissions were evaluated using public data and 536 farm operation surveys. Milk processing data were collected from 50 dairy plants nationwide. Retail and consumer GHG emissions were estimated from primary data, design estimates, and publicly available data. Total GHG emissions, based primarily on 2007 to 2008 data, were 2.05 (90% confidence limits: 1.77–2.4) kg CO₂e per kg milk consumed, which accounted for loss of 12% at retail and an additional 20% loss at consumption. A complementary analysis showed the entire dairy sector contributes approximately 1.9% of US GHG emissions. While the largest GHG contributors are feed production, enteric methane, and manure management; there are opportunities to reduce impacts throughout the supply chain.     

Greenhouse gas implications of household energy technology in Kenya

Linkages between household energy technology, indoor air pollution, and greenhouse gas (GHG) emissions have become increasingly important in understanding the local and global environmental and health effects of domestic energy use. We report on GHG emissions from common Kenyan wood and charcoal cookstoves. Our estimations are based on 29 d of measurements under the conditions of actual use in 19 rural Kenyan households. Carbon monoxide (CO), particulate matter (PM10), combustion phase, and fuel mass were measured continuously or in short intervals in day-long monitoring sessions. Emissions of pollutants other than CO and PM10 were estimated using emissions ratios from published literature. We estimated that the daily carbon emissions from charcoal stoves (5202 +/- 2257 g of C: mean +/- SD) were lower than both traditional open fire (5990 +/- 1843 g of C) and improved ceramic woodstoves (5905 +/- 1553 g of C), but the differences were not statistically significant. However, when each pollutant was weighted using a 20-yr global warming potential, charcoal stoves emitted larger amounts of GHGs than either type of woodstove (9850 +/- 4600 g of C for charcoal as compared to 8310 +/- 2400 and 9649 +/- 2207 for open fire and ceramic woodstoves, respectively; differences not statistically significant). Non-CO2 emissions from charcoal stoves were 5549 +/- 2700 g of C in 20-yr CO2 equivalent units, while emissions were 2860 +/- 680 and 4711 +/- 919 for three-stone fires and improved ceramic stoves, respectively, with statistically significant results between charcoal and wood stoves. Therefore in a sustainable fuel-cycle (i.e., excluding CO2), charcoal stoves have larger emissions than woodstoves. When the emissions from charcoal production, measured in a previous study, were included in the assessment, the disparity between the GHG emissions from charcoal and firewood increased significantly, with non-CO2 GHG emissions factors (g of C/kg of fuel burned) for charcoal production and consumption 6-13 times higher than emissions from woodstoves. Policy implications and options for environment and public health are discussed.     

Variability and uncertainty in life cycle assessment models for greenhouse gas emissions from Canadian oil sands production

Because of interest in greenhouse gas (GHG) emissions from transportation fuels production, a number of recent life cycle assessment (LCA) studies have calculated GHG emissions from oil sands extraction, upgrading, and refining pathways. The results from these studies vary considerably. This paper reviews factors affecting energy consumption and GHG emissions from oil sands extraction. It then uses publicly available data to analyze the assumptions made in the LCA models to better understand the causes of variability in emissions estimates. It is found that the variation in oil sands GHG estimates is due to a variety of causes. In approximate order of importance, these are scope of modeling and choice of projects analyzed (e.g., specific projects vs industry averages); differences in assumed energy intensities of extraction and upgrading; differences in the fuel mix assumptions; treatment of secondary noncombustion emissions sources, such as venting, flaring, and fugitive emissions; and treatment of ecological emissions sources, such as land-use change-associated emissions. The GHGenius model is recommended as the LCA model that is most congruent with reported industry average data. GHGenius also has the most comprehensive system boundaries. Last, remaining uncertainties and future research needs are discussed.     

Operation of marine diesel engines on biogenic fuels: modification of emissions and resulting climate effects

The modification of emissions of climate-sensitive exhaust compounds such as CO(2), NO(x), hydrocarbons, and particulate matter from medium-speed marine diesel engines was studied for a set of fossil and biogenic fuels. Applied fossil fuels were the reference heavy fuel oil (HFO) and the low-sulfur marine gas oil (MGO); biogenic fuels were palm oil, soybean oil, sunflower oil, and animal fat. Greenhouse gas (GHG) emissions related to the production of biogenic fuels were treated by means of a fuel life cycle analysis which included land use changes associated with the growth of energy plants. Emissions of CO(2) and NO(x) per kWh were found to be similar for fossil fuels and biogenic fuels. PM mass emission was reduced to 10-15% of HFO emissions for all low-sulfur fuels including MGO as a fossil fuel. Black carbon emissions were reduced significantly to 13-30% of HFO. Changes in emissions were predominantly related to particulate sulfate, while differences between low-sulfur fossil fuels and low-sulfur biogenic fuels were of minor significance. GHG emissions from the biogenic fuel life cycle (FLC) depend crucially on energy plant production conditions and have the potential of shifting the overall GHG budget from positive to negative compared to fossil fuels.     

Sustainability and energy development: influences of greenhouse gas emission reduction options on water use in energy production

Climate change mitigation strategies cannot be evaluated solely in terms of energy cost and greenhouse gas (GHG) mitigation potential. Maintaining GHGs at a "safe" level will require fundamental change in the way we approach energy production, and a number of environmental, economic, and societal factors will come into play. Water is an essential component of energy production, and water resource constraints will limit our options for meeting society's growing demand for energy while also reducing GHG emissions. This study evaluates these potential constraints from a global perspective by revisiting the climate wedges proposal of Pacala and Socolow (Science2004, 305 (5686), 968-972) and evaluating the potential water-use impacts of the wedges associated with energy production. GHG mitigation options that improve energy conversion or use efficiency can simultaneously reduce GHG emissions, lower energy costs, and reduce energy impacts on water resources. Other GHG mitigation options (e.g., carbon capture and sequestration, traditional nuclear, and biofuels from dedicated energy crops) increase water requirements for energy. Achieving energy sustainability requires deployment of alternatives that can reduce GHG emissions, water resource impacts, and energy costs.