生命周期评价在我国乙烯行业环境评估中的应用

采用IMPACT 2002+方法对我国的乙烯行业进行了生命周期评价(LCA)研究,分析了包括原油生产、原煤生产、原料生产、乙烯生产和电力生产5个环节在内的13种污染物排放对乙烯行业的环境影响.结果表明,乙烯工业对不可再生能源原油的消耗,对温室效应、呼吸效应和水体酸化等的环境影响潜值最为严重.减少乙烯生产环节和原料生产环节(炼油过程)的SO2、NOx、CO2等气体的排放,以及原油开采过程的CH4逸放,是改善环境影响的关键因素.同时,以石脑油为原料裂解乙烯工艺比以轻烃为原料制乙烯工艺对环境的影响要小.而煤制烯烃工艺对环境影响较大,仍具有一定改进空间.总体来看,经过近十年发展,我国乙烯行业对资源利用效率和缓解尾气排放两方面都有显著的提升.     

Environmental comparison of MESO-CLAD® process and conventional machining implementing life cycle assessment

CLAD^® process (Direct additive laser manufacturing, Construction Laser Additive Directe in French) allows the direct manufacturing of small parts, and especially in case of complex shapes, giving equivalent properties with traditional processes such as conventional machining or casting techniques. Present environmental considerations are very important for updates in legislation or in order to make economic allowances. A specified mechanical Ti₆Al₄V part is used as a support and SimaPro software allows to perform Life Cycle Assessment. This study suggests that the absence of chips production, which represents up to 80% of the titanium consumption, provides to CLAD^® process an unquestionable advantage. This process requires longer times of execution, which increase additional energy consumptions, and the comparison of this process with conventional machining demonstrates that damages to resources and to human health are highly reduced. In both cases a large part of the environmental impacts are due to the powder elaboration. Finally, CLAD^® process can add shapes on machined/casted parts and it is possible to consider the manufacture of a mechanical part via a hybrid process.     

基于生命周期评价的风力发电机碳足迹分析

本文以我国市场占用率最高的2 MW双馈式风力发电机为研究对象,采用生命周期评价(LCA)方法,核算其全生命周期过程的碳足迹和总能量需求,分析风力发电机不同生命周期阶段的环境影响,识别其减碳潜力.研究结果表明,风力发电机生产阶段、运输阶段、运行阶段和废弃处理处置阶段的碳足迹(以CO2-eq计,下同)分别为1701 t、61 t、255 t和-325 t;各生命周期阶段的总能量需求分别为10413 GJ、701 GJ、1561.95 GJ和-1081 GJ.风力发电机的碳足迹和总能量需求主要来源于生产阶段,废弃处理处置阶段材料的回收利用有效的降低了生命周期的碳足迹和总能量需求.生产阶段的碳足迹和总能量需求分别占全生命周期碳足迹和总能量需求的101%和90%;废弃处置阶段对碳足迹和总能量需求的贡献为-19%和-10%.每1k Wh风力发电的碳足迹和总能量需求分别为20.7 g和0.14 MJ,风力发电机的能量回收期为0.79年.敏感性分析表明,风力发电机的质量和废弃处置阶段的金属回收率都是风力发电机总能量需求和碳足迹的影响因素.     

Assessing environmental performance by combining life cycle assessment, multi-criteria analysis and environmental performance indicators

We present a new analytical tool, called COMPLIMENT, which can be used to provide detailed information on the overall environmental impact of a business. COMPLIMENT integrates parts of tools such as life cycle assessment, multi-criteria analysis and environmental performance indicators. It avoids disadvantages and combines complementary aspects of these three tools. The methodology is based on environmental performance indicators, expanding the scope of data collection towards a life cycle approach and including a weighting and aggregation step. A case study on the Thai pulp industry illustrates the usefulness of COMPLIMENT.     

Normative ethics and methodology for life cycle assessment

Prospective life cycle assessment (LCA) provides information on the environmental consequences of individual actions. Retrospective LCA provides information about the environmental properties of the life cycle investigated and of its subsystems. In this paper we analyse the links between the choice of methodology and different theories of normative moral philosophy. The choice of electricity data in an LCA of a conference site with local hydropower production is discussed as an illustration. The two types of LCA can be related to different theories on the characteristics of a good action. Each type of LCA, as well as each of the moral theories, can be criticised from the alternative point of departure. Decisions based on retrospective LCA can have environmentally undesirable consequences. On the other hand, prospective LCA can appear unfair and result in environmentally sub-optimised systems. Both types of LCA also have methodological limitations. We cannot conclude that one type is superior to the other, but the choice of methodology should be consistent with the information sought in the LCA.     

Simulation and life cycle assessment of process design alternatives for biodiesel production from waste vegetable oils

This study uses the process simulator ASPEN Plus^® and Life Cycle Assessment (LCA) to compare three process design alternatives for biodiesel production from waste vegetable oils that are: the conventional alkali-catalyzed process including a free fatty acids (FFAs) pre-treatment, the acid-catalyzed process, and the supercritical methanol process using propane as co-solvent. Results show that the supercritical methanol process using propane as co-solvent is the most environmentally favorable alternative. Its smaller steam consumption in comparison with the other process design alternatives leads to a lower contribution to the potential environmental impacts (PEI’s). The acid-catalyzed process generally shows the highest PEI’s, in particular due to the high energy requirements associated with methanol recovery operations.     

动态生命周期评价的研究与应用现状

生命周期评价（LCA）在理论和实际应用中存在一些局限性,包括清单和评价方法缺乏时间维度和空间维度,主要表现为缺乏对产品能源系统随时间变化的考虑,使用静态的过时的清单数据而非基于时间的动态生命周期清单数据,以及影响评价方面缺乏动态特征因子的选择和计算方法.动态生命周期评价（DLCA）是针对工业和环境系统的时间和空间变化的动态建模过程的评价方法,可大大提高传统生命周期评价的科学性和准确性.本文从3个方面对动态生命周期评价方法进行总结和评述,即将时间信息作为不确定因素的动态建模分析;生产过程或污染物排放的实时数据的获取;基于时间分化的动态特征因子的影响评价方法.通过目前的动态生命周期评价的研究现状来看,其方法框架并不统一,另外缺乏科学的时间分化的LCI计算的数学模型和软件以及生命周期影响评价的建模解决方案.因此,本文对DLCA未来的发展进行展望,以期为LCA方法的研究、应用、发展和完善提供更多的支持.     

Analysis of internally recurring unit processes in life cycle assessment

In a life cycle assessment (LCA) study, the identification and quantification of the inputs and outputs of unit processes or gate-to-gate modules are essential. In general, however, many chemical industries are composed of very complex systems with internally recurring unit processes where the upstream input to a unit process may include the downstream output from a latter unit process. Therefore, it is rather difficult to identify and quantify the inputs/outputs for those internally recurring unit processes, respectively, for life cycle inventory analysis purposes.In this study, several calculation methods which are applicable to complex systems with internally recurring unit processes are proposed as follows: (1) Determination of the inputs/outputs associated with each unit process by using simultaneous equations. In this proposal, any parameter linked to an upstream process is treated as a ‘variable’ and the set of other parameters is considered to be a ‘constant’. (2) Determination of the inputs/outputs by using appropriate cut-off criteria based on the cumulative total mass contribution. (3) Determination of the inputs/outputs by using appropriate cut-off criteria based on the number of occurrences of an individual recurring set of unit processes.The results from these methodologies are analyzed using a hypothetical example and an actual case from the petrochemical industry. These methods enhance the reliability and consideration of on-site information in recurring unit processes. In particular, the determination of the inputs/outputs associated with each unit process by using simultaneous equations does not add assumptions regarding cut-off criteria selection and provides the advantages of time conservation, consistency and affinity to on-site consideration.     

A methodology for assessing soil quantity and quality in life cycle assessment

Changes resulting from economic activities in the quantity and quality of soil in a system under analysis are important considerations in a life cycle assessment (LCA) study because they affect the safeguard subjects of resources and future agricultural productivity. In the approach proposed here, soil is treated as an ancillary which may leave the system in a form different from that at entry. Relevant factors describing possible changes in the soil include: soil mass, nutrients, weeds and weed seeds, pathogens, nutrients, salts, pH, organic matter, and soil texture and structure. Many of the factors can be included by modelling the effects of infrequent activities benefitting the crop(s) under analysis. Three additional factors require separate assessment: changes in the mass of soil, its organic matter content, and soil compaction. Taken together, these approaches provide an integrated assessment method capable of accounting for the overall impacts of agricultural production on soil.     

煤焦油无害化处置研究及生命周期评价

根据煤焦油的物理化学性质,提出了将煤焦油送往燃煤电厂焚烧处置的优化处置方案. 运用环境影响指标标准化和AHP权重定量法对,煤焦油处置系统进行了生命周期评价分析(LCA).结果表明,与原处置工艺相比,优化后环境负荷降低了30.79%;燃煤电厂焚烧将煤焦油焚烧产生的热能可以转化为电能,实现资源的循环利用.     

Software as a bridge between theory and practice in life cycle assessment

Three mutually dependent elements are required for the application of life cycle assessment: methodology, data and software. Obviously, the design of software is determined by the methodology and the type of data available. Conversely, the development of software dictates the way in which data should be collected and recorded, and improves the theoretical framework, as it forces one to state the principles clearly and unambiguously. The influence of the development of software on both data and methodology is addressed and illustrated by examples, with reference to two key terms: transparency and explicitness. Three types of influence are distinguished: the design of a protocol, the formulation in terms of recipes, and the presentation of data.     

生命周期评价在玉米种植及深加工产品中的应用

对LCA在玉米种植环境影响研究中的目标与范围定义、清单分析、环境影响指标与计算方法、结果解释等方面的研究进行了梳理分析,其中大部分文献均对碳足迹进行了计算,CML（Institute of Environmental Sciences of the University of Leiden）、ReCiPe（许多LCA领域研究人员共同开发）和IPCC（Intergovernmental Panel on Climate Change）方法是应用最多的3种方法,经分析计算得到国外玉米种植单位产量碳足迹均值为0.50kg CO₂-eq/kg,我国的均值为0.58kg CO₂-eq/kg.同时本文也对LCA在玉米深加工产品中的研究进展进行了分析整理,对今后LCA应用于玉米种植及深加工产品中的发展方向进行了展望.     

耦合健康风险与生命周期评价的场地修复环境经济影响评估

我国污染场地数量众多,对当地环境和健康安全造成了巨大威胁,亟待开展治理修复,同时也需要关注修复过程的绿色可持续性.本文基于绿色可持续修复（GSR）的理念,提出了健康风险评价（HRA）和生命周期评价（LCA）耦合的评估框架,用于计算结合健康风险和修复二次环境影响的净环境效益（NEB）,并以中国西南地区某多环芳烃和汞污染的工业场地为例,在现行的修复目标制定框架内,对不同修复目标下的NEB进行了评估.结果表明,在不同权衡选择下,案例最佳的修复目标带来的NEB是直接选择筛选值目标的1.6~15倍,单位经济投入带来的NEB是直接选择筛选值的3~7倍.决策者可应用提出的综合评估框架,平衡当地环境质量改善和修复过程的二次影响,以提高场地修复工程的环境经济可持续性.     

技术生命周期评价进展及其在碳中和领域应用趋势分析

技术生命周期评价可为技术改进、科学决策及碳中和提供方法支撑。利用CiteSpace软件研究了近20年技术生命周期评价研究特点、变化趋势、重点领域、演进路径及其在碳中和领域的研究进展。结果表明：技术生命周期评价相关文献出版量整体呈上升趋势,2006年以后进入快速发展阶段;发文主要集中在工程学、生态学、环境科学、环境工程、其他理工学科、能源与燃料和绿色可持续发展技术等学科。生命周期评价的研究对象、评价方法及应用是近年来的研究热点,能源生产技术、碳足迹及废物处理技术是技术生命周期评价的研究重点,体系、模型、框架、不确定性等方面是评价方法完善要点,方法适用性开发和综合性评判成为后续发展方向,提高可持续、效能、决策支撑的有效性是提高生命周期评价技术应用的突破点。碳足迹的生命周期评价可用于指导碳中和目标的实现及路径选择,将其他评估方法与生命周期评估相结合正在成为一种趋势,可提升技术全面综合评估的准确性及有效性,为实现碳中和目标提供有效参考。

     

Application of life cycle assessment to the Portuguese pulp and paper industry

In this paper, the Life Cycle Assessment (LCA) methodology is applied to Portuguese printing and writing paper in order to compare the environmental impact of the use of two kinds of fuels (heavy fuel oil and natural gas) in the pulp and paper production processes. The results of inventory analysis and impact assessment show that the pulp and paper production processes play an important role in almost all of the analysed parameters, which do not always result in an important contribution to the corresponding impact categories. The substitution of heavy fuel oil by natural gas in the pulp and paper production processes seems to be environmentally positive.     

基于生命周期评价的钢铁厂碱渣固碳技术比较研究

本研究以3种钢铁厂碱渣直接法固碳技术为研究对象,该技术将钢渣进行碳酸化处理,可快速永久地将CO2固化储存在钢渣中,气固相反应可分别在高压釜、泥浆反应器和超重力旋转床的水溶液中一步完成,并将其分别定义为T1、T2、T3.通过Umberto软件建立生命周期模型,对3种技术的资源环境影响进行评估.结果表明,T1的环境影响最高,其次为T3,T2的环境影响最小.技术评价显示,T3在技术效率、资源消耗、环境影响方面具有较好的综合效益.敏感性分析表明,加热效率的敏感性系数分别为0.97、0.97和0.46.转换率与温室气体排放的关系分别呈上升、倒U型和下降的变化趋势.提高加热效率、合理利用热源及选择合适的技术效率,将有利于技术优化,减少技术的环境影响,提高固碳效率.     

生命周期影响评价方法及本地化研究进展

为推动我国生命周期影响评价方法的构建,采用文献梳理法对生命周期影响评价方法及本地化研究的现状与未来发展方向进行分析。首先回顾了生命周期评价的起源与发展,探讨了生命周期评价在我国取得的进展与存在的不足;其次对生命周期影响评价理论与方法进行了介绍,并利用文献计量学方法分析了我国学者在生命周期评价时所使用的方法,结果显示77%的研究均采用国外的影响评价方法;最后梳理了我国生命周期影响评价方法的本地化研究进展,分析了现阶段生命周期影响评价方法的3点不足,包括所选取的指标及基准值亟须更新,模型系统性和完整性需要加强,模型深入研究有待展开,并提出要探索构建适合我国国情的完整全面的生命周期影响评价方法以及相应的参数基准值,从而提高我国生命周期评价结果的真实性、准确性,为环境政策制定以及相关产业发展提供决策支持。

     

Environmental impacts of cocoa production and processing in Ghana: life cycle assessment approach

Ghana is the world's second largest producer of cocoa beans. In addition to exporting raw cocoa beans, the country also processes some of its beans into finished and semi-finished cocoa products for both the local and international markets. This paper is aimed at providing a comprehensive picture of the environmental impacts associated with cocoa production and processing in Ghana by applying the life cycle assessment (LCA) methodology. The analysis considered the entire system required to produce and process 1 kg of cocoa bean. It included the extraction of raw materials (e.g. fossil fuels, minerals), the production of farming inputs (e.g. fertilizers and pesticides) and all agricultural operations in the field (e.g. tillage, fertilizer and pesticides application, harvest, etc.). Transportation of beans to processing factory and industrial processing of the beans into cocoa butter, liquor, cake and powder were also included. The study was conducted in accordance with the international ISO procedural framework for performing LCA in the ISO 14040–14043 series.The overall environmental impacts resulting from cocoa production and processing activities and improvement options towards the sustainability of the system studied are presented and discussed.