• Energy Research
• 2021-2025close
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• 7. Clean energy close

Abstract High power pseudocapacitors are extremely relevant to answer specific needs in the current energy transition arena and to implement an efficient renewable energy society. However, literature shows that are still open gaps concerning improvement of their energy density at high power, conversion efficiency, cost and cycle life. Electrodes based on active transition metal compounds, and in particular metal sulphides, evidence high potential to meet these objectives. This work discusses the dependence on the synthesis route of the charge storage mechanism of manganese sulphide-based materials and relates the pseudocapacitive response of these electrodes with their polycrystalline nature. Results reveal that a manganese oxy-sulphide mixture can achieve a high specific capacitance of 231 F.g−1 at 0.5 A/g in a 0.65 V active window. These values represent a 31.5 % increase compared to pure rambergite, γ-MnS, and 436 % compared to pure hausmannite Mn3O4 prepared under the same conditions. Moreover, the results show that manganese oxy-sulphide electrodes are characterized by good charge retention (73%), and superior long term capacity retention (above 86%) after 5000 cycles, evidencing potential for high power energy storage applications.

This deliverable reports on the main characteristics of the thermal store design, collecting information from previous deliverables in order to define the sensors��� location. In addition, it reports on the integration of the system with the ASTEP components, and some simulations have been done using the UPCT model to verify that the demand of both end users is satisfied. This has covered summer and winter periods and both charging and discharging of the stores.

It is now environmentally desirable and legally mandatory to add renewable fuels such as ethanol or ethyl tert-butyl ether to gasoline. However, biofuels affect, among other properties, the distillation curve of gasoline, which is subject to strict regulations. This work presents a simple mathematical model capable of accurately predicting the influence that the addition of these oxygenates has on the distillation curve. In order to address this issue, it is essential to find a simple mathematical correlation between the boiling temperatures of the hydrocarbons present in gasoline and the properties (boiling temperature and volume or molar concentration of ethanol) of the corresponding azeotropic mixtures formed with ethanol. Power functions have been assumed to model the temperature composition diagrams of the vapour-liquid equilibrium. Experimental data previously published by these and other authors have been used to fit and validate the model. The results provided by the mathematical model can be of great interest to understand the process of fuel evaporation in spark-ignition engines or the adjustment of distillation cuts in refineries, in order to comply with the regulations, in terms of the distillation curve, after adding ethanol or ethyl tert-butyl ether.

The present paper exhibits a real time assessment of a robust Energy Management Strategy (EMS) for battery-super capacitor (SC) Hybrid Energy Storage System (HESS). The proposed algorithm, dedicated to an electric vehicular application, is based on a self-gain scheduled controller, which guarantees the H∞ performance for a class of linear parameter varying (LPV) systems. Assuming that the duty cycle of the involved DC-DC converters are considered as the variable parameters, that can be captured in real time, and forwarded to the controller to ensure both; the performance and robustness of the closed-loop system. The subsequent controller is therefore time-varying and it is automatically scheduled according to each parameter variation. This algorithm has been validated through experimental results provided by a tailor-made test bench including both the HESS and the vehicle traction emulation system. The experimental results demonstrate the overall stability of the system, where the proposed LPV supervisor successfully accomplishes a power frequency splitting in an adequate way, respecting the dynamic of the sources. The proposed solution provides significant performances for different speed levels.

The most widely used process for hydrogen production is steam methane reforming. It can be carried out using a membrane reactor in which simultaneous hydrogen production and purification occur. Mathematical modeling of these reactors plays a key role in the selection of the design and operating parameters that yield high performance for the reactor. This review study discusses, synthesizes, and compares different mathematical modeling studies on the packed bed membrane reactors for hydrogen production from methane found in the literature. Different approaches used in these modeling studies for the hydrogen permeation steps, reaction kinetic expressions, phases involved (pseudo-homogeneous and heterogeneous), and spatial dimensions (one, two, and three dimensional) are given.

The olive oil mill wastewater (OMW) is a by-product (with a high organic load) derived from the production of the olive oil. The OMW steam reforming (OMWSR) process was studied herein, aiming to decrease the environmental damage of such effluents; simultaneously, the waste is economically and energetically valorized with the H-2 production. Several Ni-containing catalysts were prepared and tested to compare their performances for the OMWSR using a synthetic OMW effluent; still, stability tests were also carried out. The materials were extensively characterized: thermogravimetric analysis, temperature programmed oxidation/reduction, temperature-programmed desorption of CO2/NH3, chemisorption of H-2, inductively coupled plasma optical emission spectrometry and physical adsorption-desorption of N-2 at-196 & DEG;C. Amongst the materials tested, the Ni-Ru/SiO2 sample stood out, exhibiting high catalytic performance: at 400 & DEG;C, the H-2 yield (> 8 mol(H2)& BULL;mol(OMW)(-1)) and conversion of total organic carbon (asymptotic to 75%) were high during all the 24 h of the long-term test, with only a small deactivation being noticed.

This report aims to provide concept designs to integrate the SunDial/TES system with the MANDREKAS and ArcelorMittal end-users. These concept designs are important to understand how the ASTEP system will be integrated with the end-users including the tailored designs for the specific needs of each end-user. The end-user specific ASTEP system is introduced and existing heating/cooling systems are explained in schematic diagrams. A small number of integration options are presented in detailed schematics. Possible integration components such as steam generator for MANDREKAS and pipe heater for ArcelorMittal are investigated at the component level. In addition, key fluid properties at the critical locations such as inlet and outlet of the components are summarised.

Abstract The gas suction rate of a conventional liquid–gas ejector pump was measured on a modular pilot plant unit utilizing convergent nozzles and a water–air system. Hydraulic characteristics were measured for various water flow rates, suction and discharge pressures, and ejector geometries, covering a wide range of configurations and operating conditions. The device configurations, providing the most stable and reproducible results, were identified. The air flow rates measured with these configurations were correlated by a simple, three-parameter correlation with a relative standard deviation (RSD) of 11%. The performance and behavior of the ejector in less stable configurations are discussed and the recommendations for the design of optimally operating units are provided. Finally, the correlation is tested against available literature data. The ejectors with comparable geometry agree well with the proposed correlation (within 20% RSD). The reasonable agreement with the discussed differences is found for other literature data. This comparison results in the validation of the proposed correlation to provide a safe prediction of minimal gas entrainment in units of various geometries, orientation and operating conditions.

Abstract Concrete is identified in the literature as a suitable material for thermal energy storage applications, with even innovative application potentials such as storage media in concentrating solar power plants. To ensure a suitable heat transfer among concrete components, the binder material of concrete (cement paste) require further research and understanding to this aim. In particular, the thermal stability of cement paste under temperature cycled conditions arises as a research gap. In this study, ordinary Portland and calcium aluminate cement types were selected using a low water-cement ratio. Thermo-mechanical properties were studied before and after 1, 10, and 25 or 50 thermal cycles at 200 °C, 400 °C, 600 °C, and 800 °C. Although ordinary Portland cement paste showed micro-cracking propagation after 25 thermal cycles from ambient temperature to 200 °C and 400 °C, both cement pastes preserved their integrity, being compressive strength higher in ordinary Portland cement. On the contrary, after 25 or 50 thermal cycles at 600 °C and 800 °C, only calcium aluminate cement preserved its integrity, while ordinary Portland cement revealed a fragmentation status. Despite the compressive strength decrease in calcium aluminate paste at 600 °C and 800 °C, as a result of porosity increase, the properties were maintained after 10 thermal cycles. However, thermal conductivity in calcium aluminate paste was reduced nearly 50% after the first cycle at temperatures higher than 200 °C.

In the recent years, some experimental forms of housing (cohousing and social housing) have developed in Italy, which also take on the features of real energy communities. These initiatives have been planned and implemented thanks to the active participation and investments of the people involved in the project. Their primary aim is to implement new form of shared housing, but by adopting renewable generation systems and sharing both energy production and consumption, they are contributing to foster the energy transition process. In this research, we studied the management of the energy resource and the social interactions among the cohousers. Moreover, we analysed the social impacts on the surrounding territory in order to know as they can widespread the clean energy technologies and social innovation processes. To do this, we compared two experiences of collaborative housing: the first one, active since some years in Northern Italy, is a bottom-up initiative set up by the voluntary action of some families and individuals. Its goal is to share common spaces and activities, but also to produce and use renewable energy with a view to economic and environmental sustainability. The second one is a social cohousing, established in Messina (Southern Italy) and implemented by the Fondazione di Comunità di Messina. The project involves people who live in socio-economic difficulties. Through the ESCO Solidarity & Energy, the Fondazione has designed and applied energy systems to allow the tenants to become prosumers and prosumagers.