Experimental investigation on CO2methanation process for solar energy storage compared to CO2-based methanol synthesis

The utilization of the captured CO2 as a carbon source for the production of energy storage media offers a technological solution for overcoming crucial issues in current energy systems. Solar energy production generally does not match with energy demand because of its intermittent and non-programmable nature, entailing the adoption of storage technologies. Hydrogen constitutes a chemical storage for renewable electricity if it is produced by water electrolysis and is also the key reactant for CO2 methanation (Sabatier reaction). The utilization of CO2 as a feedstock for producing methane contributes to alleviate global climate changes and sequestration related problems. The produced methane is a carbon neutral gas that fits into existing infrastructure and allows issues related to the aforementioned intermittency and non-programmability of solar energy to be overcome. In this paper, an experimental apparatus, composed of an electrolyzer and a tubular fixed bed reactor, is built and used to produce methane via Sabatier reaction. The objective of the experimental campaign is the evaluation of the process performance and a comparison with other CO2 valorization paths such as methanol production. The investigated pressure range was 2–20 bar, obtaining a methane volume fraction in outlet gaseous mixture of 64.75% at 8 bar and 97.24% at 20 bar, with conversion efficiencies of, respectively, 84.64% and 99.06%. The methanol and methane processes were compared on the basis of an energy parameter defined as the spent energy/stored energy. It is higher for the methanol process (0.45), with respect to the methane production process (0.41–0.43), which has a higher energy storage capability

Acoustic mitigation of noise in ports: an original methodology for the identification of intervention priorities

Abstract The paper presents an original methodology for the identification of intervention priorities through a tailored priority index IP in areas that are highly-exposed to port noise. The methodology is applied to a case study developed in the framework of the European project ANCHOR, acronym of Advanced Noise Control strategies in HarbOuR, funded as part of the announcement Life 2017. In detail, the paper discusses the results of its application in the assessment of the evolution of port noise impacts in the city of Melilla, Spain. The methodology has been applied considering the port with or without the realization of an expansion project on three different time periods; differences between standard and the summer traffic peak season have been considered. Finally, the paper evaluates the realization of cold ironing in the most impacting port area, the passenger (Ro-Pax) terminal. The results of the analyses demonstrate how the measure is a key action to mitigate noise in port areas. The methodology is not limited to the identification of city areas that needs to be protected; it also aims to identify port areas where anti-noise actions would produce the greatest effect. The index also allows to build a ranking to understand where anti-noise actions are more useful and urgent

Definition of Probability That Energy Production Differs from Demand, a Statistical Approach

Starting from the average trend of energy demand and energy production related to a specific user, the goal is to produce an immediate estimate, as close as possible to the true value (clearly achievable only through a precise and punctual measurement), of the difference existing between these two values, in order to "a priori" understand whether an energy production surplus should be expected, or the opposite trend will occur. If energy produced exceeds the request, two solutions will be possible. An accumulation system can be provided, that allows to avoid taking energy from the grid whenever the trend reserves and the demand exceeds the production. The second solution consists in directly introduce the whole surplus of energy produced in the electricity grid. Similarly, even if the energy required exceeds the amount of energy produced, two different solutions can be envisaged. In both cases, it will be necessary to take energy from the electricity grid. An accumulation system could be created, sized on the maximum difference between production and energy demand, evaluated when the production exceeds the request (if the production never exceeds the request, it would not make sense to talk about accumulation) or, even in this case, a direct exchange might be promoted, both incoming and outgoing, with the electricity grid. Topic of the present paper is to not reasoning any more in terms of energy performances as a function of time but, on the contrary, determine the probability that the difference existing between production and demand assumes a certain value and, based on this, estimate the amount of energy to be stored and/or exchange with the grid

Experimental Investigation on the Effect of Phase Change Materials on Compressed Air Expansion in CAES Plants

The integration of renewable energy in the electrical grid is challenging due to the intermittent and non-programmable generated electric power and to the transmission of peak power levels. Several energy storage technologies have been studied to find a solution to these issues. In particular, compressed air energy storage (CAES) plants work by pumping and storing air into a vessel or in an underground cavern; then when energy is needed, the pressurized air is expanded in an expansion turbine. Several CAES configurations have been proposed: diabatic, adiabatic and isothermal. The isothermal process seems to be the most promising to improve the overall efficiency. It differs from conventional CAES approaches as it employs near-isothermal compression and expansion. Currently, there are no commercial isothermal CAES implementations worldwide, but several methods are under investigation. In this paper, the use of phase change materials (PCM) for isothermal air expansion is discussed. Air expansion tests in presence of PCM were carried out in a high-pressure vessel in order to analyze the effect of PCM on the process. Results show that in presence of PCM near isothermal expansion conditions occur and therefore they affect positively the value of the obtainable expansion work

Remote Sensing Techniques for Urban Heating Analysis: A Case Study of Sustainable Construction at District Level

In recent years, many new districts in urban centres have been planned and constructed to reshape the structure and functions of specific areas. Urban regeneration strategies, planning and design principles have to take into account both socioeconomic perspectives and environmental sustainability. A district located in the historical city centre of Terni (Italy), Corso del Popolo, was analysed to assess the construction effects in terms of surface urban heat island (SUHI) mitigation. This district is an example of urban texture modification planned in the framework of the regeneration of the ancient part of the town. The changes were realised starting from 2006; the new area was completed on June 2014. The analysis was carried out by processing Landsat 7 ETM+ images before and after the interventions, retrieving land surface temperature (LST) and albedo maps. The map analysis proved the SUHI reduction of the new area after the interventions: as confirmed by the literature, such SUHI mitigation can be ascribed to the presence of green areas, the underground parking, the partial covering of the local roadway and the shadow effect of new multi-storey buildings. Moreover, an analysis of other parameters linked to the impervious surfaces (albedo, heat transfer and air circulation) driving LST variations is provided to better understand SUHI behaviour at the district level. The district regeneration shows that wisely planned and developed projects in the construction sector can improve urban areas not only economically and socially, but can also enhance the environmental impact

Transient Heat Transfer in Radiant Floors: A Comparative Analysis between the Lumped Capacitance Method and Infrared Thermography Measurements

The paper presents a simplified mathematical model to describe the transient heat transfer of a radiant floor heating system. A purpose-built test room has been realized to investigate the actual thermal response of a concrete radiant floor in unsteady-state conditions. Beyond the temperature sensors needed for the standard thermal analysis of the heat transfer inside the chamber, the floor temperature was retrieved by means of an infrared thermography camera, in order to validate more precisely the proposed analytical model. The infrared thermography analysis gives interesting information on the floor temperature distribution during the transient, highlighting the pipes’ layout and, if present, inhomogeneous floor zones. The thermal images have been elaborated in order to set and tune the colour map. A portion of the image has been defined for measuring the surface floor temperatures with a previous evaluation of the parameters dealing with the thermographic technique, in order to perform the quantitative survey. The comparison results show that the calculated air and floor temperatures substantially agree with the temperatures measured by infrared thermography and thermocouples, provided that the boundary conditions obtained by the field measurements are strictly reproduced in the lumped capacitance mathematical model. The difference between the two approaches results in values lower than 4 °C during the entire monitoring period: a satisfactory outcome, considering the approximations of the analytical method. The proposed model and its infrared thermography measurements validation represent a useful tool to understand at first sight the floor radiant panels behaviour in the start-up and switch off period, at the aim of gather useful information for the difficult task of their regulation

Noise mapping and Action Plan realization within LIFE+ “NADIA” project

NADIA (Noise Abatement Demonstrative and Innovative Actions and information to the public, LIFE 2009 ENV/IT/000102) is a project funded by the European Commission Directorate General "Environment" as part of the announcement Life + 2009 dealing mainly with the topic of road traffic noise. Detailed information on the project can be found on the project website [1] and in [2, 3]. The areas analysed in the project are 5 roads managed by the Provinces of Genova, 3 managed by the Province of Savona and parts of the agglomerations of Prato and Vicenza. Due to their traffic volume (for roads: higher than 3 million vehicles/year) or number of inhabitants (for agglomerations: higher than 100.000), the European Directive 2002/49/EC [4], implemented in Italy by the Legislative Decree n°194/2005 [5], imposes the realization of Strategic Noise Maps and Noise Action Plans for each of the considered areas. During Action n°2 of the project, data were collected for the realization of noise maps and the evaluation of the indicator “population exposed to noise” of the considered roads/agglomerations. Noise mapping activities were performed in Action n°3. The results of these activities are reported respectively in the Deliverable 1 and 3 of the project, available on the NADIA project website [1]. The results of the noise simulations are now being used for the realization of Noise Action Plans (Action n°4). The paper reports the methodology that is being developed for their realization in the framework of the NADIA projec

IL CATASTO ACUSTICO DELLA REGIONE UMBRIA

L’inquinamento acustico rappresenta senza dubbio una delle forme di inquinamento ambientale oggetto di maggiore attenzione. La diffusione sul territorio delle sorgenti e l’ampia varietà delle stesse rende complessa la conoscenza del fenomeno nelle sue di-verse forme, dalle caratteristiche di emissione delle specifiche sorgenti, alla valutazione dell’impatto sull’ambiente, alla stima della popolazione esposta. A differenza di altre fonti di inquinamento, ne consegue anche una certa difficoltà a costruire dei sistemi in-formatici capaci di gestire i dati utili al legislatore, agli amministratori locali e agli enti di controllo nella gestione della problematica, in termini di individuazione delle critici-tà, di finalizzazione delle azioni di controllo e di scelta delle azioni di mitigazione

The Water Footprint of the Wine Industry: Implementation of an Assessment Methodology and Application to a Case Study

An original methodology for the Water Footprint Assessment (WFA) of a Product for the wine-making industry sector is presented, with a particular focus on the evaluation procedure of the grey water. Results obtained with the proposed methodology are also presented for an Italian case study. The product was analyzed using a life-cycle approach, with the aim of studying the water volumes of each phase according to the newly-released ISO 14046 international standard. The functional unit chosen in this study is the common 0.75 liter wine bottle. An in-house software (V.I.V.A.) was implemented with the goal of accounting for all the contributions in a cradle-to-grave approach. At this stage, however, minor water volumes associated with some foreground and background processes are not assessed. The evaluation procedure was applied to a case study and green, blue, and grey water volumes were computed. Primary data were collected for a red wine produced by an Umbrian wine-making company. Results are in accordance with global average water footprint values from literature, showing a total WF of 632.2 L/bottle, with the major contribution (98.3%) given by green water, and minor contributions (1.2% and 0.5%) given by grey and blue water, respectively. A particular effort was dedicated to the definition of an improved methodology for the assessment of the virtual water volume required to dilute the load of pollutants on the environment below some reference level (Grey WF). The improved methodology was elaborated to assure the completeness of the water footprint assessment and to overcome some limitations of the reference approach. As a result, the overall WF can increase up to 3% in the most conservative hypotheses

Production of an innovative film-filter for sun simulators: theoretical analysis.

Sun simulators are employed to test the performance of photovoltaic devices according to the standard IEC 61215. Photovoltaic manufacturers need to insert a sun simulator at the end of the PV production chain in order to measure the I-V curve and to evaluate the peak power of PV devices. The sun simulator needs specific lamps to simulate solar spectrum and a specific filter to simulate atmosphere absorbance. Such filter can cost over 6 € per square centimeter. The aim of this work is to develop an alternative filter. In particular, both chemical analysis and spectrophotometric measurements are carried out to evaluate if the Air Mss 1.5 G filter can be replaced by a cheaper material. Preliminary simulations show how specific compounds coated on glass surface can absorb sun spectrum such as the A.M 1,5 filter but with lower costs