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Abstract: The way in which GHG (greenhouse gas) emissions associated with grid electricity consumption is handled in different LCA (life cycle assessment) studies, varies significantly. Apart from differences in actual research questions, methodological choices and data set selection have a significant impact on the outcomes. These inconsistencies result in difficulties to compare the findings of various LCA studies. This review paper explores the issue from a methodological point of view. The perspectives of ALCA (attributional life cycle assessment) and CLCA (consequential life cycle assessment) are reflected. Finally, the paper summarizes the key issues and provides suggestions on the way forward. The major challenge related to both of the LCA categories is to determine the GHG emissions of the power production technologies under consideration. Furthermore, the specific challenge in ALCA is to determine the appropriate electricity production mix, and in CLCA, to identify the marginal technologies affected and related consequences. Significant uncertainties are involved, particularly in future-related LCAs, and these should not be ignored. Harmonization of the methods and data sets for various purposes is suggested, acknowledging that selections might be subjective. [Copyright &y& Elsevier]

Eco-design that addresses the consumption of resources and energy, as well as pollution emissions from a product life-cycle perspective, is an effective way to solve environmental problems. However, the optimal eco-design solution is hardly generated in the conceptual design stage due to the complex association of the life cycle design information. To this end, this paper proposes a new eco-design model based on a life cycle integrated framework to effectively manage life cycle information in the conceptual design phase. In this work, (1) The life cycle-oriented model is proposed to integrate the product design information in terms of a systematic association mechanism between function, structure, material and process to construct the design space. (2) A life cycle design scenario-based similarity matching method is developed to support the environmental impact assessment of design options in the design space. (3) A hope tree-based heuristic search algorithm with the principle of minimizing environmental impact is proposed to efficiently obtain the eco-design solution. An application for eco-design of the lift equipment is given to demonstrate the capability of the proposed method. The results show that the environmental impact of the generated eco-design solution is improved by 19.48%, and the material and use stage has the highest environmental impact which accounts for 39.59% and 47.74% respectively. This work provides a targeted method for guiding designers to implement eco-design in the conceptual design phase through the life cycle. [Display omitted] • An integrated life cycle model is proposed to express the design information of function, structure, material and process. • A scenario-based similarity matching method is proposed to acquire the LCI for the design options. • Hope tree-based algorithm is used to efficiently obtain the optimal eco-design solution. [ABSTRACT FROM AUTHOR]

Municipal heating by coal contributes considerably to the haze pollution in Chinese cities during cold period, e.g., Beijing 53%. It is widely considered that, as a supplement of natural gas, the use of coal-based synthetic natural gas (SNG) to replace coal for municipal heating is conductive to mitigate the haze pollution in metropolitan areas. Would it still be a good alternative if the whole life cycle of SNG were taken into consideration? In this study, SNG as an alternative for municipal heating is analyzed in comparison with coal. To target cleaner production, life cycle assessment methodology is used to analyze SNG contribution to haze pollutants and greenhouse gases (GHGs) emissions, as well as energy consumption. Compared to coal heating route, SNG heating route could reduce 44% of the haze pollutants emissions from life cycle perspective and up to 98% of the emissions in urban area. Thus, if municipal heating were entirely supplied by natural gas and SNG, there would be 52% less haze pollutants emissions in winter of Beijing. However, this “good” performance is at the cost of transferring haze pollutants emissions from urban areas to SNG-producing regions. It is also at the cost of consuming 90% more coal and emitting 65% more GHGs than the coal heating route from life cycle point of view. To tackle the problems of haze pollutants transfer and the increase of GHGs emissions, the paper suggests implementing ecological compensation and carbon tax policies in the coal-based SNG industry. [ABSTRACT FROM AUTHOR]

The consumption of non-renewable primary energy resources results in their depletion, which is becoming absolutely crucial for the sustainable development of humankind. The production of electricity based on burning fossil fuels involves harmful emissions. Thus, the additional consumption of primary energy is required in order to make up for the environmental impact. The of that consumption of primary exergy per unit of useful products is called the index of TEC (thermoecological cost). When the whole life cycle is considered, we have to do with the LC TEC (life-cycle thermoecological cost). The paper presents the concept of a life cycle assessment based on the thermoecological cost implemented in an integrated OFC (oxy-fuel combustion) power plant with CO 2 capture, transport and storage. A mathematical model evaluating the LC TEC was applied and the example utilised Polish conditions. The obtained value of the LC TEC of the analyzed CCS (Carbon capture and storage) system (with 90% CO 2 emission reduction) is about 22% higher than the average value for polish coal-fired power plants (without CCS). The results of sensitivity analysis concerning LC TEC allow to conclude that the operation phase dominates (over 99.5%), thus the construction, repairs and decommissioning phases for CCS systems could be neglected in further studies concerning the depletion of non-renewable natural resources. [ABSTRACT FROM AUTHOR]

Evaluations of the environmental sustainability of lifestyles and consumption practices have been taking centre stage in European research projects in recent years. Considerable work has been undertaken on the environmental assessment of food consumption patterns, and several analytical tools and methodologies have been proposed to quantify the environmental burden of production and consumption. Claims have been made in several international reports that the Mediterranean diet offers the best consumption pattern in terms of both the environment and health, but there has never been a specific assessment of the Mediterranean diet in comparison with other food consumption behaviours. This paper explores the environmental burdens of the Mediterranean diet applied in the Italian context. The environmental performance of this diet is compared to the national average diet in Italy, as well as to two empirical scenarios of healthy and vegetarian food consumption patterns. The environmental burdens of the different diets are assessed in terms of their energy consumption and their carbon footprint using a hybrid IOA-LCA method. This method considers the positive aspects of both bottom-up methodologies (e.g. life cycle assessment – LCA) and top-down methodologies (e.g. input–output analysis – IOA). The results allow several comparisons to be made between the different diets. When compared with the national average diet, the Mediterranean diet reveals an improvement in environmental performance of 95.75 MJ (2.44%) and 27.46 kg CO 2 equivalent (6.81%) per family. The best overall environmental performance can be found with the vegetarian diet in which energy consumption is 3.14% lower and the carbon footprint 12.7% lower than the national average diet. [ABSTRACT FROM AUTHOR]

This study deals with the interface between energy consumption and its related emissions in the manufacturing of one cubic meter medium density fiberboard (MDF) in Iran and provides a comprehensive life cycle inventory (LCI) data for production process. The study was developed following the methodological guidelines of ISO 14040. Inventories data for a gate-to-gate assessment of MDF manufacturing were collected by on-site surveys. Ten impact categories including of: Abiotic depletion (AD), Acidification (AC), Eutrophication (EP), Global warming (GW), Ozone layer depletion (OLD), Fresh water aquatic ecotoxicity (FE), Marine aquatic ecotoxicity (ME), Human toxicity (HT), Terrestrial ecotoxicity (TE) and Photochemical oxidation (PO) in three subsystem of manufacturing process were assessed. The subsystem of fiber preparation was the major contributor to the environmental impacts. Urea-formaldehyde (UF) resin production was identified as the main hotspot, except in AD, AC, OLD and PO impacts that natural gas, electricity, transport and production process were the main hotspots, respectively. Moreover, Tube dryer, MDF saw and hogger were the most effective sectors in the emissions of production process. Results for substitution of natural gas showed that except in some impacts categories, use of alternative source of thermal energy such as wood residue could improve emissions from manufacturing. [ABSTRACT FROM AUTHOR]