Ana M. López-Sabirón

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 profile of latent energy storage materials applied to industrial systems.

Industry sector is an intensive-energy consumer and approximately 20-50% of industrial energy consumption is lost as waste heat. Therefore, there is a great potential for reducing energy consumption and, subsequently, decreasing the fossil fuels used if this lost energy can be recovered. Thermal Energy Storage (TES) based on Latent Heat Storage systems (LHS) using Phase Change Materials (PCMs) has become one of the most feasible solutions in achieving energy savings through waste heat recovery, especially when there is a mismatch between the supply and consumption of energy processes. In this paper, a shell and tube heat exchanger incorporating PCMs has been considered to store the excess energy available in an industrial process. Several attempts have been made to design the most appropriate system considering many cost-benefit and technical criteria to maximise the heat recovery. However, the environmental criterion also is an important factor when determining whether this technology is not only energy and cost-efficient but also environmentally friendly, considering the whole life of the system from its manufacture to its disposal. To this end, this research includes a Life Cycle Assessment (LCA) to determine whether the energy savings of conventional fuels during the operation stage are large enough to balance the environmental impact originated in an industrial TES system including the manufacture, use and disposal phases. Inputs and outputs of each management stage have been defined, and the inventory emissions calculated by SIMAPRO v7.3.2. A midpoint and endpoint approaches have been carried out using two methods, CML 2001 and Eco-indicator 99, respectively. As a preliminary result, a promising reduction in the overall impacts was obtained by the use of this technology. From the environmental impact results, a matrix of possible technical solutions is displayed, to improve the environmental performance.

Refuse derived fuel (RDF) plasma torch gasification as a feasible route to produce low environmental impact syngas for the cement industry

Plasma torch gasification (PTG) is currently researched as a technology for solid waste recovery. However, scientific studies based on evaluating its environmental implications considering the life cycle assessment (LCA) methodology are lacking. Therefore, this work is focused on comparing the environmental effect of the emissions of syngas combustion produced by refuse derived fuel (RDF) and PTG as alternative fuels, with that related to fossil fuel combustion in the cement industry. To obtain real data, a semi-industrial scale pilot plant was used to perform experimental trials on RDF-PTG. The results highlight that PTG for waste to energy recovery in the cement industry is environmentally feasible considering its current state of development. A reduction in every impact category was found when a total or partial substitution of alternative fuel for conventional fuel in the calciner firing (60 % of total thermal energy input) was performed. Furthermore, the results revealed that electrical energy consumption in PTG is also an important parameter from the LCA approach.

Thermal Storage Materials for Enhancing Indoor-Dwelling Temperature Conditions

The adequate impregnation of phase change materials (PCMs) into porous construction materials in a building can be significantly improved if technical and environmental aspects are evaluated. Sensible and latent heat storage using PCMs is well known technology governed by two principles Sensible Heat Storage (SHS) and Latent Heat Storage (LHS) but additional studies focused on the specific industrial applications considering its recent progress are required. One of the most recent progresses that have been achieved in this area is the large number of commercial PCMs available. This fact makes that the simple task of selecting the appropriate PCM considering technical and environmental aspects will not be evident. Large latent heat and high thermal conductivity, as well as, a melting temperature in the practical range of operation, low in cost, non-toxicant, non-corrosive and low environmental impacts are keys for choosing the suitable PCMs. In this chapter, an energy (ESP-r) and environmental (SIMAPRO) modelling study is carried out and presented for enhancing indoor-dwelling temperature conditions considering a real climate severity.

Accumulation of De-Icing Salt and Leaching in Spanish Soils Surrounding Roadways

The environmental implications of soil salinity caused by accumulation of de-icing salt and leaching in soils of northeastern Spain were examined. For this purpose, the concentrations of ions associated with diagnosing and managing this problem were evaluated from several measurements performed over one year along a road. This analysis demonstrated a higher concentration of soluble Na+ in the soil 3 m from a road in the northernmost part of the study area in February, which made the soil saline-sodic. Data from the rest of the study period (during the spring and summer) demonstrated that the de-icing salt moved to areas farther south by runoff water, which caused environmental impacts by modifying soil characteristics. These results suggest that leaching of Ca2+ and Mg2+ cations occurred faster in the studied systems in sodic soils. Leaching of these cations may affect plant yield, and results in environmental impacts within 3–30 m from the road. Awareness of this impact will be useful for developing future strategies for evaluating and reporting these complex relationships within Spain’s transport system and environment.