295 research outputs found
Carbon footprint of particleboard: a comparison between ISO/TS 14067, GHG Protocol, PAS 2050 and Climate Declaration
This article aims to assess: i) the carbon footprint (CF) of particleboard produced in Portugal, and ii) the influence of different methodological issues in the particleboard CF calculation by comparing four CF methodologies (ISO/TS 14067; GHG Protocol Product Standard; PAS 2050; Climate Declaration). A life-cycle model was developed for particleboard (functional unit: 1 m3). Both cradle-to-gate and cradle-to-grave (end-of-life scenarios: incineration and landfill) assessments were performed. Six methods to assess delayed emissions were analyzed. The main methodological differences between the CF methodologies are the treatment of biogenic CO2, multifunctionality, and unit process exclusions (e.g. capital goods). A wide range of CFs was calculated: −939 to 188 kg CO2 eq/m3 (cradle-to-gate); 107 to 201 kg CO2 eq/m3 (cradle-to-grave; incineration) and −692 to 433 kg CO2 eq/m3 (cradle-to-grave; landfill). The inclusion (negative CF) or exclusion (positive CF) of biogenic carbon storage in the reported CF dominated the differences in results and the ranking of end-of-life scenarios strongly depended on that assumption. ISO/TS 14067, the GHG Protocol and PAS 2050 explicitly include both emissions and removals of biogenic CO2 in the CF calculation. On the other hand, the Climate Declaration does not account for biogenic CO2 or carbon storage, which may bias the comparison with competing products that do not store biogenic carbon (e.g. fossil-based materials). The CF of particleboard was also very sensitive to the different approaches to deal with multifunctionality in the incineration process by the various CF methodologies. Moreover, although not mandatory, delayed emission accounting significantly affected the results for the incineration scenario. Capital goods accounted for 12–20% of the CF. Future guidelines for wood-based panels, such as Product Category Rules, should, therefore, require that carbon storage is assessed and reported, accounting of waste-to-energy burdens is harmonized and capital goods are included
Uncertainty Analysis of the Life-Cycle Greenhouse Gas Emissions and Energy Renewability of Biofuels
Biofuels can contribute substantially to energy security and socio-economic development. However, significant disagreement and controversies exist regarding the actual energy and greenhouse gas (GHG) savings of biofuels displacing fossil fuels. A large number of publications that analyze the life-cycle of biofuel systems present varying and sometimes contradictory conclusions, even for the same biofuel type (Farrell et al., 2006; Malca and Freire, 2004, 2006, 2011; Gnansounou et al., 2009; van der Voet et al., 2010; Borjesson and Tufvesson, 2011). Several aspects have been found to affect the calculation of energy and GHG savings, namely land use change issues and modeling assumptions (Gnansounou et al., 2009; Malca and Freire, 2011). Growing concerns in recent years that the production of biofuels might not respect minimum sustainability requirements led to the publication of Directive 2009/28/EC in the European Union (EPC 2009) and the National Renewable Fuel Standard Program in the USA (EPA 2010), imposing for example the attainment of minimum GHG savings compared to fossil fuels displaced. The calculation of life cycle GHG emission savings is subject to significant uncertainty, but current biofuel life-cycle studies do not usually consider uncertainty. Most often, life-cycle assessment (LCA) practitioners build deterministic models to approximate real systems and thus fail to capture the uncertainty inherent in LCA (Lloyd and Ries, 2007). This type of approach results in outcomes that may be erroneously interpreted, or worse, may promote decisions in the wrong direction (Lloyd and Ries, 2007; Plevin, 2010). It is, therefore, important for sound decision support that uncertainty is taken into account in the life-cycle modeling of biofuels. Under this context, this chapter has two main goals: i) to present a robust framework to incorporate uncertainty in the life-cycle modeling of biofuel systems; and ii) to describe the application of this framework to vegetable oil fuel in Europe. In addition, results are compared with conventional (fossil) fuels to evaluate potential savings achieved through displacement. Following this approach, both the overall uncertainty and the relative importance of the different types of uncertainty can be assessed. Moreover, the relevance of addressing uncertainty issues in biofuels life-cycle studies instead of using average deterministic approaches can be evaluated, namely through identification of important aspects that deserve further study to reduce the overall uncertainty of the system
Greenhouse gas assessment of soybean production: implications of land use change and different cultivation systems
The increase in soybean production as a source of protein and oil is being stimulated by the growing demand for livestock feed, food and numerous other applications. Significant greenhouse gas (GHG) emissions can result from land use change due to the expansion and cultivation of soybean. However, this is complex to assess and the results can vary widely. The main goal of this article is to investigate the life-cycle GHG balance for soybean produced in Latin America, assessing the implications of direct land use change emissions and different cultivation systems. A life-cycle model, including inventories for soybean produced in three different climate regions, was developed, addressing land use change, cultivation and transport to Europe. A comprehensive evaluation of alternative land use change scenarios (conversion of tropical forest, forest plantations, perennial crop plantations, savannah and grasslands), cultivation (tillage, reduced tillage and no-tillage) and soybean transportation systems was undertaken. The main results show the importance of land use change in soybean GHG emissions, but significant differences were observed for the alternative scenarios, namely 0.1–17.8 kg CO2eq kg−1 soybean. The original land choice is a critical issue in ensuring the lowest soybean GHG balance and degraded grassland should preferably be used for soybean cultivation. The highest GHG emissions were calculated for tropical moist regions when rainforest is converted into soybean plantations (tillage system). When land use change is not considered, the GHG intensity varies from 0.3 to 0.6 kg CO2eq kg−1 soybean. It was calculated that all tillage systems have higher GHG emissions than the corresponding no-tillage and reduced tillage systems. The results also show that N2O emissions play a major role in the GHG emissions from cultivation, although N2O emission calculations are very sensitive to the parameters and emission factors adopted
Dynamic fleet-based life-cycle greenhouse gas assessment of the introduction of electric vehicles in the Portuguese light-duty fleet
Purpose
Reducing greenhouse gas (GHG) emissions from the transportation sector is the goal of several current policies and battery electric vehicles (BEVs) are seen as one option to achieve this goal. However, the introduction of BEVs in the fleet is gradual and their benefits will depend on how they compare with increasingly more energy-efficient internal combustion engine vehicles (ICEVs). The aim of this article is to assess whether displacing ICEVs by BEVs in the Portuguese light-duty fleet is environmentally beneficial (focusing on GHG emissions), taking into account the dynamic behavior of the fleet.
Methods
A dynamic fleet-based life-cycle assessment (LCA) of the Portuguese light-duty fleet was performed, addressing life-cycle (LC) GHG emissions through 2030 across different scenarios. A model was developed, integrating: (i) a vehicle stock sub-model of the Portuguese light-duty fleet; and (ii) dynamic LC sub-models of three vehicle technologies (gasoline ICEV, diesel ICEV and BEV). Two metrics were analyzed: (i) Total fleet LC GHG emissions (in Mton CO2 eq); and (ii) Fleet LC GHG emissions per kilometer (in g CO2 eq/km). A sensitivity analysis was performed to assess the influence of different parameters in the results and ranking of scenarios.
Results and discussion
The model baseline projected a reduction of 30–39 % in the 2010–2030 fleet LC GHG emissions depending on the BEV fleet penetration rate and ICEV fuel consumption improvements. However, for BEV introduction in the fleet to be beneficial compared to an increasingly more efficient ICEV fleet, a high BEV market share and electricity emission factor similar or lower to the current mix (485 g CO2 eq/kWh) need to be realized; these conclusions hold for the different conditions analyzed. Results were also sensitive to parameters that affect the fleet composition, such as those that change the vehicle stock, the scrappage rate, and the activity level of the fleet (11–19 % variation in GHG emissions in 2030), which are seldom assessed in the LCA of vehicles. The influence of these parameters also varies over time, becoming more important as time passes. These effects can only be captured by assessing Total fleet GHG emissions over time as opposed to the GHG emissions per kilometer metric.
Conclusions
These results emphasize the importance of taking into account the dynamic behavior of the fleet, technology improvements over time, and changes in vehicle operation and background processes during the vehicle service life when assessing the potential benefits of displacing ICEVs by BEVs.MIT-Portugal ProgramFonds Europeen de Developpement Economique et Regional (FEDER, Programa Operacional Factores de Competitividade--COMPETE)Fundação para a Ciência e a Tecnologia (Portugal) (project grant FCOMP-01-0124-FEDER-029055 (PTDC/EMS-ENE/1839/2012))Fundação para a Ciência e a Tecnologia (Portugal) (project grant FCOMP-01-0124-FEDER-021495 (PTDC/SEN-TRA/117251/2010))Fundação para a Ciência e a Tecnologia (Portugal) (project grant CENTRO-07-0224-FEDER-002004)Fundação para a Ciência e a Tecnologia (Portugal) (doctoral grant SFRH/BD/51299/2010
Life‐Cycle Assessment of olive oil addressing alternative production systems: how to deal with olive pomace valorization
Olive oil is an important product of the so-called “Mediterranean Diet”. In Portugal, about 90 000 tonnes of olive oil were produced yearly in the last agricultural campaigns. The main objective of this paper is to present a comparative life-cycle assessment (LCA) of olive oil produced from four types of cultivation systems (familiar, traditional, intensive and organic) and two olive oil extraction processes (three-phase and two-phase extraction), addressing the valorization of olive pomace. The most remarkable difference between three- and two-phase extraction is related to the co-products and residues produced: the three-phase process results in three fractions (olive oil, olive pomace and olive mill wastewater), whereas the two-phase extraction (a more recent and increasingly used process in order to avoid the production of olive mill wastewater) consumes less water and generates, together with olive oil, a suspension called olive wet pomace.
A life-cycle model and inventory was implemented for the entire olive oil chain, including olive cultivation and olive oil extraction (about 5-7 kg of olives are required to produce one liter of olive oil), as well as valorization of olive pomace (three-phase extraction) and olive wet pomace (two-phase) to produce olive pomace oil and extracted pomace. Two approaches for dealing with multifunctionality were analyzed: i) allocation based on market prices of coproducts (olive oil and olive pomace) and ii) substitution (“avoided burdens” approach) of extracted pomace (displacing conventional fuel in energy intensive processes) and olive pomace oil (displacing virgin oil in biodiesel production). The environmental impacts were calculated for four impact categories (ReCiPe method): greenhouse gas (GHG) intensity, terrestrial acidification, freshwater and marine eutrophication. The cumulative energy demand (CED) method was used to calculate non-renewable primary energy (NRPE).
The results (price based allocation) showed that olive cultivation was the life-cycle phase which contributed the most to the overall environmental impacts (55-95% to GHG intensity, 80-98% to acidification and 70-100% to eutrophication), except for the familiar cultivation system with no fertilizers and pesticides being applied. Fertilizers production and application contributed more than 43% to the environmental impacts of traditional, intensive and organic cultivation. Results calculated with the “avoided burdens” approach are highly dependent on the type of virgin oil displaced by olive pomace oil. This research shows the importance of olive cultivation practices and olive pomace valorization to reduce the life-cycle impacts of olive oil.
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Valorization of energetic material from ammunition in civil explosives
Ammunitions that have reached the end of life (or become obsolete) are considered hazardous waste. The Armed Forces have significant amounts of ammunition (a residue with high energy content) that need to be eliminated. Currently, in Portugal and other developed countries, ammunition is disposed of in incinerators with sophisticated gas treatment systems; however, this decommissioning process has important limitations in terms of incinerator capacity, high costs and energy requirements (Ferreira et al., 2013). This paper describes the valorization of ammunition by incorporation into civil explosives, as an alternative to conventional decommissioning. Therefore, the main goal of this paper is to assess the potential energy and environmental benefits of incorporating energetic material in ammonium nitrate (AN) based emulsions, civil explosives widely used for mining and road construction, allowing for the displacement of both disposal of military explosives and production of an equivalent quantity of civil explosives.
Previous work involving experiments with energetic material incorporated in AN emulsion has shown that a simple processing technique (grinding) is sufficient to blend the energetic material into the emulsion matrix, with no formation of new chemical species. A life-cycle model has been implemented based on primary data for the grinding process and on previous studies on conventional decommissioning processes (Ferreira et al., 2013) and production of ammonium nitrate emulsion (Ferreira et al., 2015). The model implemented follows the “avoided burdens” approach to calculate the environmental burdens avoided when 1 kg of TNT equivalent from ammunition is incorporated into civil explosives. Results were calculated based on three complementary life-cycle impact assessment methods: primary energy, six environmental impact categories (CML), and three toxicological categories (USEtox).The results show that re-using ammunition through valorization of energetic material has considerably lower impacts (approximately 80% for all categories) compared to conventional decommissioning, mainly due to avoided incineration and gas treatment.
C. Ferreira, J. Ribeiro, R. Mendes, F. Freire, Life-Cycle Assessment of Ammunition Demilitarization in a Static Kiln, Propellants Explos. Pyrotech. 38, 2013, 296 – 302.
C. Ferreira, F. Freire, J. Ribeiro, Life-cycle assessment of a civil explosive, Journal of Cleaner Production 89, 2015, 159 – 164
Tele-control de robots móviles desde Internet
En este artículo se presenta un sistema que permite controlar un robot móvil, desde cualquier lugar, utilizando como medio de comunicación entre el operador y el robot la red Internet, utilizando el método de control denominado “control continuo”, las interfaces de comunicación utilizan los protocolos TCP/IP, el robot controlado es un robot que utiliza un sistema de agarre mediante ventosas, lo que le permite escalar por paredes verticales, con diferente inclinación. El sistema informático se desarrolló en tecnologías Java, y herramientas abierta
Control de las ruedas delanteras de robots móviles
Para un control preciso de robots móviles es indispensable crear modelos matemáticos que permitan emular la diná- mica de movimiento, para tomar decisiones en el estado de diseño del sistema, en este trabajo se presenta un modelo simplificado de la dinámica de las ruedas delanteras de un robot móvil, controlado a través de la red Internet. Internet se comporta como un elemento retardador de señales, el valor de retardo es un valor aleatorio que depende de varios factores, para contrarrestar esta dificultad se utilizo un controlador Difuso, que permite disminuir al mínimo este factor retardador
Comprehensive economic and spatial bio-energy modelling . Chania : CIHEAM / INRA
To cite th is article / Pou r citer cet article -------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Abstract: Life Cycle Activity Analysis (LCAA) -a mathematical programming decision support model for the optimization of the entire life cycle of products -is presented. LCAA is a new tool for the mapping of hierarchical production and recovery chains, their impact on the environment, and for a holistic evaluation of new technologies, environmental strategies or policies. LCAA involves three successive stages of analysis: i) a description of all participating activities (processing, transport, use, recovery, …) as a good travels from its "cradle" to its "grave", including the inventory of ancillary materials and energy supplied to each activity, economic costs and environmental burdens; ii) the formulation and numerical solution of a linear or nonlinear mathematical programming model and iii) the evaluation of a set of environmental scenarios of interest to policy-decision-makers or stakeholders. It is shown how LCAA contributes to the conceptualization of Industrial Ecology, which can be seen as a new paradigm for the integration of environmental and economic performance. The antecedents of LCAA (classical Activity Analysis adjoined to the environmental Life Cycle Assessment framework) are surveyed. Illustrative conceptual mathematical programming formats are discussed and the potential of LCAA, the type of problems to be addressed and its relevance to environmental policy are further explored
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