Ignacio Zabalza Bribián

Phase change material applications in buildings: an environmental assessment for some Spanish climate severities.

This work proposes an environmental analysis based on the life cycle assessment (LCA) methodology. LCA was applied to determine if energy savings are large enough to balance the environmental impact caused during phase change material (PCM) manufacture and its installation on tiles. Inputs and outputs of each management stage have been defined and the inventory emissions were calculated by SIMAPRO v 7.3.2. Emissions were classified into several impact categories; climate change, human toxicity, acidification, ozone depletion, particulate matter formation and eutrophication. Three commercial PCMs, evaluated using five different Spanish weather climates, were studied to explore a wide range of conditions. The main results conclude that the use of PCM can reduce the overall energy consumption and the environmental impacts. This reduction is strongly influenced by the climate conditions and the PCM introduced.

Environmental-benefit analysis of two urban waste collection systems

Sustainable transportation infrastructure and travel policies aim to optimise the use of transportation systems to achieve economic and related social and environmental goals. To this end, a novel methodology based on life cycle assessment (LCA) has been developed in this study, with the aim of quantifying, in terms of CO2 emissions equivalent, the impact associated with different alternatives of waste collection systems in different urban typologies. This new approach is focussed on saving energy and raw materials and reducing the environmental impact associated with the waste collection system in urban areas, as well as allowing the design and planning of the best available technologies and most environment-friendly management. The methodology considers a large variety of variables from the point of view of sustainable urban transport such as the location and size of the urban area, the amount of solid waste generated, the level of social awareness on waste separation procedures, the distance between houses and waste collection points and the distance from the latter to the possible recovery plants and/or landfills, taking into account the material and energy recovery ratio within an integrated waste management system. As a case study, two different waste collection systems have been evaluated with this methodology in the ecocity Valdespartera located in Zaragoza, Spain, consisting of approximately 10,000 homes: (i) a system based on traditional truck transportation and manual collection, and (ii) a stationary vacuum waste collection system. Results show that, when operating at loads close to 100%, the stationary collection system has the best environmental performance in comparison with the conventional system. In contrast, when operating at load factors around 13% the environmental benefits in terms of net CO2-eq. emissions for the stationary collection system are around 60% lower in comparison with the conventional one.

Environmental Performance of Applying Alternative Energies to the Collection, Transport and MBT Plant Within an Integrated MSW Management System

This study extends the environmental assessment of Municipal Solid Waste (MSW) management strategies using Life Cycle Assessment (LCA) methodology with the objective of evaluating the environmental implications of applying alternative energies to the collection, transport and operation of a Mechanical–Biological Treatment (MBT) plant within an integrated MSW management system. To this end, the environmental implications of the use of alternative energies in two stages of the MSW management system were taken into account: (1) collection and transportation systems for the residual household waste of MSW; and (2) the MBT plant operation including the recovery of its residual fraction. As a case study, the MSW management system of the Ecocity Valdespartera and the MBT plant in Zaragoza have been evaluated. These sites are located in the Autonomous Community of Aragon (Spain). In this study, different scenarios of alternative energy supply from renewable energy sources were evaluated at each stage of the management system. Impact assessment for each of the scenarios considered the following six impact categories: (1) acidification (kg SO2 eq.); (2) global warming (100 years) (kg CO2 eq.); (3) eutrophication (kg PO4 eq.); (4) photochemical oxidation (kg C2H4 eq.); (5) abiotic depletion (kg Sb eq.); and (6) ozone layer depletion (kg CFC-11 eq.). These categories are contained in the CML 2 baseline 2,000 impact assessment method V2.05. The software Simapro V. 7.3.2 was also used. Results show that when alternative energy supply scenarios from renewable energy sources (RES) are included in both the collection system and the operation of the MBT, environmental benefits can be achieved in comparison to current state of affairs. In this scenario, the avoided emissions are greater than those generated in most of the impact categories under study. The results identify scientific and technical processes that can be used to promote fundamental changes in the management of upstream flows of MSW in MBT plants and in its operation.