Double Green Process: a low environmental impact method for recycling of CdTe,a-Si and CIS/CIGS thin-film photovoltaic modules

On the basis of the method for managing the end of life of CdTe photovoltaic panels previously proposed by the authors, a new method for the recycling of all types of thin-film panels (CdTe, a-Si and CIS/CIGS) has been developed and optimised under a research project founded by Enel Foundation and CRUI Foundation. The DGP process has been developed through a feasibility study carried out from three points of view: technical, environmental and economic. The process is composed by two sub-processes matched to each other, one suitable for CdTe panels (named DGPa) and the other one for a-Si and CIS/CIGS panels (DGPb). The Double Green Panel process is based mainly on mechanical treatments with a minimum use of chemicals and it is characterised by a greater level of automation and a high flexibility in production capacity. The potential environmental impacts of various configurations of the DGP process have been extensively analysed with LCA tool in order to develop an environmentally friendly process. The economic feasibility has been assessed through the Discounted Cash Flow Analysis (DCFA) method. The revenues associated to the recovery of valuable and common materials and the recycling costs have been taken into account.     

煤与秸秆成型燃料的复合生命周期对比评价

利用复合生命周期对比评价方法,引入能量返还率、资源耗竭系数、环境影响负荷和生命周期成本4个参数,对煤和秸秆成型燃料在整个生命周期内的能源消耗、环境影响和经济性做了对比分析.同时,为了平衡能源、环境与经济三者之间的关系,建立EEE (Energy, Environment, Economic)综合指标进行整体评价.结果表明,在整个生命周期内,与煤相比,秸秆成型燃料的能量返还率低、资源耗竭系数小.秸秆成型燃料的全球变暖潜值、酸化潜值、富营养化潜值、工业烟尘、粉尘潜值及固体废弃物潜值均比煤小,因此,秸秆成型燃料的环境影响负荷比煤小.秸秆成型燃料的EEE指标值比煤小79.8%,所以,从平衡生命周期能源消耗、环境排放和经济性角度出发,秸秆成型燃料具有替代煤的潜力.但是,秸秆成型燃料的生命周期成本比煤高,其大力推广需要政府的财政补贴.     

苏州垃圾填埋生命周期清单分析

采用理论计算和实测相结合的方法,求得了苏州七子山垃圾填埋埋场的生命周期清单。实践证明,理论计算和实测相结合是清单分析的有效方法,对今后的同类研究具有参考意义。研究中获得的清单包括生活垃圾的收集和运输、垃圾填埋的物耗和能耗,以及每吨填埋垃圾所排放的大气和水污染物的量,并考察了填埋气用于发电后对清单的影响。这些结果可以为众多的产品生命周期评价提供数据支持。     

含油污泥无害化处置优化研究及生命周期评价

提出含油污泥的优化处置方案,并通过生命周期评价方法(LCA)对优化方案进行环境影响评价。结果表明,与原处置工艺相比优化后环境负荷降低了99.62%。     

水泥窑共处置废农药生命周期评价研究

国内在水泥窑共处置废农药方面的研究处于起步阶段.通过开展试烧试验,以生命周期评价方法(LCA)为研究手段,对水泥窑共处置废农药技术的环境影响进行评价,并与危险废物的其他处置方法做比较,以处置1 kg危险废物为功能单位.结果表明,常规危险废物焚烧的综合环境负荷指数为1.428 4×1012a-1,而水泥窑中共处置废农药的综合环境负荷指数为0.183 9×10-12a-1,远低于常规危险废物焚烧.     

循环流化床锅炉燃煤技术热电厂生命周期评价

运用生命周期评价方法,应用Gabi5.0软件对采用循环流化床锅炉燃煤技术的热电企业进行资源耗竭和环境影响分析,计算各生产单元生命周期清单的全球变暖潜值、酸化效应潜值、富营养化潜值、非生物资源耗竭潜值、人体毒性潜值以及光化学烟雾和臭氧生成潜值等主要环境影响类型,对燃煤发电过程进行生命周期评价。结果表明,全球变暖和非生物资源耗竭为发电运行过程中主要的环境影响因素,分别占53%和15.05%;锅炉燃烧阶段的环境影响最重,占整个生命周期影响值的77.12%,并且除生物耗竭潜值外的其他5项指标均为发电运行阶段各个单元中最高。采用SNCR脱硝技术减少燃烧过程中NOx的排放量,并对该技术方案进行生命周期评价,比较方案实施前后的环境影响。     

Environmental consequence analysis for resource depletion

Resource depletion is of concern to both present and future generations in terms of access to resources. It is a prominent impact category within life cycle assessment (LCA) and sustainability assessment. This paper examines existing resource depletion approaches and indicators in the context of natural gas depletion, and their limitations in modelling the wider environmental consequences of resource consumption. Some existing models assume substitution of scarce fossil fuels with an alternative fossil fuel or mix, but do not consider all of the subsequent change in impacts. An additional methodology is proposed to measure the impact changes when fossil fuel substitution occurs as a result of scarcity. The methodology will demonstrate the effect of resource scarcity for individual processes but also multiple processes which operate at different levels of resource consumption with varying degrees of impacts. The methodology is applied to a scarcity situation of natural gas in Australia, where black coal is substituted for gas. It is first applied to natural gas consumed for electricity generation only. In the second case, the methodology is applied to the substitution of natural gas for both electricity generation and hydrogen production. The varying impacts on emissions to air and water, together with solid waste generation and water depletion, as a result of the substitution are used to reflect the consequences of fossil fuel depletion. The indicators also provide information on the impacts of substitution in each product, thus enabling users to prioritise products based on the impacts produced during natural gas allocation.     

城市生活垃圾处理方式生命周期评价的比较研究

生命周期评价理论与方法作为一种量化环境影响的工具,在诸多领域中得到了广泛的应用。在垃圾处理领域,生命周期评价最早在20世纪90年代得到应用。生命周期评价与城市生活垃圾处理的有效结合,将促进城市生活垃圾的减量化、资源化、无害化目标的实现。总结了生命周期评价理论与方法在城市生活垃圾处理中的应用现状。对国内不同城市生活垃圾处理方式环境影响因子进行比较分析,诸如全球变暖潜力、酸化潜力和富营养化潜力等因子。针对其目标范围定义、数据收集、评价方法的选择、结果解释及工艺改进等方面指出了目前研究的局限性和不足。并对未来城市生活垃圾处理生命周期评价的发展方向进行展望。     

铅酸蓄电池生命周期评价

铅酸蓄电池是世界上产量最大、用途最广的一种二次电池。铅酸蓄电池生命周期过程中每一个环节都有可能对环境带来不利影响,评估从生产到废弃处理关键过程中对环境的影响,可以为制定有效的管理政策提供科研支撑。目前,尚缺乏针对我国特色的铅酸蓄电池行业全生命周期评价的研究,造成此行业的污染防治无据可依。因此,本研究针对铅酸蓄电池的生命周期进行评价,通过设定研究目的与范围、收集数据与分析清单、获得影响评价和解释结果,研究了铅酸蓄电池对环境的影响,结果表明铅酸蓄电池在生产环节的板栅浇铸过程和废弃处理环节的脱硫过程应属于管理中着重控制的部分。     

基于生命周期评价的城市固体废弃物处理模式研究进展

通过回顾2003-2010年国内外不同城市固体废弃物管理体系生命周期评价结果,列举比较了不同固体废弃物处理模式下的全球变暖潜力、酸化潜力和净能源效用等影响评价因子的大小,得出城市固体废弃物处理模式环境影响等级:填埋的环境影响潜值最大,焚烧的环境影响潜值小于填埋,而结合堆肥后环境影响潜值降低;此外,将固体废弃物资源化引入到处理模式后,特别是垃圾源头分类回收后,环境影响潜值大大降低。结合我国城市固体废弃物处理现状,提出单一的处理模式应转变为综合处理模式,多种生活垃圾处理方式适当的有机结合,因地制宜地开展固体废弃物资源化管理,以及餐厨垃圾源头分类收集处理等建议,为政府能有效利用城市固体废弃物处理设施的能力提供参考。