• Energy Research

Abstract During the last years several authors have been studying the main factors influencing changes in energy consumption, ie production volume, production structure and energy intensity. Thus, a number of methods to quantify these factors have been suggested. In this paper one of those methods is partially modified and is applied to the Italian situation for the period 1975–85 in order to try to point out the role played by the various factors which have caused changes in energy consumption in Italy.

Abstract During the last years several authors have been studying the main factors influencing changes in energy consumption, ie production volume, production structure and energy intensity. Thus, a number of methods to quantify these factors have been suggested. In this paper one of those methods is partially modified and is applied to the Italian situation for the period 1975–85 in order to try to point out the role played by the various factors which have caused changes in energy consumption in Italy.

The aim of the study presented in this article is to assess, from an environmental standpoint, a set of eco-innovations applied to the production process of an automotive component. The eco-innovations were developed by a supply network of small- and medium-sized enterprises (SMEs) in the framework of a project named “Hi-reach”. The component considered is a motorcycle rear wheel spindle. The conventional version is obtained by machining a single forged steel part. The Hi-reach version is indeed manufactured by joining a shaft to a flange; in addition, conventional surface treatments are replaced by a plasma-enhanced chemical vapour deposition (PECVD) treatment and other machining steps are improved. This process was conceived with the aim of maintaining (or enhancing) the technical performance of the spindle and reducing production costs. A Life Cycle Assessment (LCA) was carried out to compare the two scenarios described. Those eco-innovations resulted in significant improvements of the environmental performance of the analysed component, ranging, on average, between 50% and 70% for the impact indicators considered. Our results also highlight the role of SMEs in promoting process eco-innovations and the increasing relevance of LCA as a tool to support decision making in manufacturing.

The aim of the study presented in this article is to assess, from an environmental standpoint, a set of eco-innovations applied to the production process of an automotive component. The eco-innovations were developed by a supply network of small- and medium-sized enterprises (SMEs) in the framework of a project named “Hi-reach”. The component considered is a motorcycle rear wheel spindle. The conventional version is obtained by machining a single forged steel part. The Hi-reach version is indeed manufactured by joining a shaft to a flange; in addition, conventional surface treatments are replaced by a plasma-enhanced chemical vapour deposition (PECVD) treatment and other machining steps are improved. This process was conceived with the aim of maintaining (or enhancing) the technical performance of the spindle and reducing production costs. A Life Cycle Assessment (LCA) was carried out to compare the two scenarios described. Those eco-innovations resulted in significant improvements of the environmental performance of the analysed component, ranging, on average, between 50% and 70% for the impact indicators considered. Our results also highlight the role of SMEs in promoting process eco-innovations and the increasing relevance of LCA as a tool to support decision making in manufacturing.

Abstract This paper aims at evaluating the environmental impact of two types of organic fraction of municipal solid waste treatment techniques – composting and anaerobic digestion with post-composting – by using the life cycle assessment (LCA) methodology. The analysis concerns a facility of municipal solid waste selection and composting, which is located in Italy and where currently there is only a composting line. Two LCA implementations will be presented -- one on the current status and one on the future option – where, according to the plant expansion plan, an anaerobic digestion line is expected to be introduced. This line will allow obtaining electricity and heat as a result of a cogeneration process fuelled by the produced biogas. Following the characterisation results, currently the compost production phase assumes the highest values in 9 out of 18 analysed impact categories, while the landfill phase prevails in the remaining 9. As far as the option to be implemented in the future is concerned, the stage that affects the most (for 8 categories) is sewage treatment, followed by landfill (6 of them) and finally by the compost production (for the remaining 4). The parallel analysis of the two organic waste treatment methods showed that the best one is the anaerobic/composting digestion solution, obtaining lower scores with respect to the sole composting option (apart from the photochemical formation of oxidants impact category).

Abstract This paper aims at evaluating the environmental impact of two types of organic fraction of municipal solid waste treatment techniques – composting and anaerobic digestion with post-composting – by using the life cycle assessment (LCA) methodology. The analysis concerns a facility of municipal solid waste selection and composting, which is located in Italy and where currently there is only a composting line. Two LCA implementations will be presented -- one on the current status and one on the future option – where, according to the plant expansion plan, an anaerobic digestion line is expected to be introduced. This line will allow obtaining electricity and heat as a result of a cogeneration process fuelled by the produced biogas. Following the characterisation results, currently the compost production phase assumes the highest values in 9 out of 18 analysed impact categories, while the landfill phase prevails in the remaining 9. As far as the option to be implemented in the future is concerned, the stage that affects the most (for 8 categories) is sewage treatment, followed by landfill (6 of them) and finally by the compost production (for the remaining 4). The parallel analysis of the two organic waste treatment methods showed that the best one is the anaerobic/composting digestion solution, obtaining lower scores with respect to the sole composting option (apart from the photochemical formation of oxidants impact category).

Purpose Consequential LCA (CLCA) is becoming widely used in the scientific community as a modelling technique which describes the consequences of a decision. However, despite the increasing number of case studies published, a proper systematization of the approach has not yet been achieved. This paper investigates the methodological implications of CLCA and the extent to which the applications are in line with the theoretical dictates. Moreover, the predictive and explorative nature of CLCA is discussed, highlighting the role of scenario modelling in further structuring the methodology. Methods An extensive literature review was performed, involving around 60 articles published over a period of approximately 18 years, and addressing both methodological issues and applications. The information was elaborated according to two main aspects: What for (questions and modes of LCA) and what (methodological implications of CLCA), with focus on the nature of modelling and on the identification of the affected processes. Results and discussion The analysis points out that since the modelling principles of attributional LCA (ALCA) and CLCA are the same, what distinguishes the two modes of LCA is the choice of the processes to be included in the system (i.e. in CLCA, those that are affected by the market dynamics). However, the identification of those processes is often done inconsistently, using different arguments, which leads to different results. We suggest the use of scenario modelling as a way to support CLCA in providing a scientifically sound basis to model specific product-related futures with respect to technology development, market shift, and other variables. Conclusions The CLCA is a sophisticated modelling technique that provides a way to assess the environmental consequences of an action/decision by including market mechanisms into the analysis. There is still room for improvements of the method and for further research, especially in relation to the following aspects: Clarifying when and which market information is important and necessary; understanding the role of scenario modelling within CLCA; and developing a procedure to support the framing of questions to better link questions to models. Moreover, we suggest that the logic of mechanisms could be the reading guide for overcoming the dispute between ALCA and CLCA. Going further, this logic could also be extended, considering CLCA as an approach-rather than as a modelling principle with defined rules-To deepen LCA,providing the conceptual basis for including more mechanisms than just the market ones.

Purpose Consequential LCA (CLCA) is becoming widely used in the scientific community as a modelling technique which describes the consequences of a decision. However, despite the increasing number of case studies published, a proper systematization of the approach has not yet been achieved. This paper investigates the methodological implications of CLCA and the extent to which the applications are in line with the theoretical dictates. Moreover, the predictive and explorative nature of CLCA is discussed, highlighting the role of scenario modelling in further structuring the methodology. Methods An extensive literature review was performed, involving around 60 articles published over a period of approximately 18 years, and addressing both methodological issues and applications. The information was elaborated according to two main aspects: What for (questions and modes of LCA) and what (methodological implications of CLCA), with focus on the nature of modelling and on the identification of the affected processes. Results and discussion The analysis points out that since the modelling principles of attributional LCA (ALCA) and CLCA are the same, what distinguishes the two modes of LCA is the choice of the processes to be included in the system (i.e. in CLCA, those that are affected by the market dynamics). However, the identification of those processes is often done inconsistently, using different arguments, which leads to different results. We suggest the use of scenario modelling as a way to support CLCA in providing a scientifically sound basis to model specific product-related futures with respect to technology development, market shift, and other variables. Conclusions The CLCA is a sophisticated modelling technique that provides a way to assess the environmental consequences of an action/decision by including market mechanisms into the analysis. There is still room for improvements of the method and for further research, especially in relation to the following aspects: Clarifying when and which market information is important and necessary; understanding the role of scenario modelling within CLCA; and developing a procedure to support the framing of questions to better link questions to models. Moreover, we suggest that the logic of mechanisms could be the reading guide for overcoming the dispute between ALCA and CLCA. Going further, this logic could also be extended, considering CLCA as an approach-rather than as a modelling principle with defined rules-To deepen LCA,providing the conceptual basis for including more mechanisms than just the market ones.