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AbstractThe aim is to develop a catalysed water-based capture process, avoiding the energy intensive steam stripping steps necessary with amine solvents. The naturally occurring zinc metallo-enzyme carbonic anhydrase/hydratase (CAH) can concentrate CO2 using a reversible hydration/dehydration cycle at neutral pH and at ambient temperatures. Some tripodal complexes of zinc (II)–[zinc-itrilo-tris(2-benzimidazoyl-methyl-6-sulfonic acid, (zinc-L1S), and zinc-tris(2-benzimidazoylmethyl)-amine, (zinc-LI)], and also cadmium (II), cobalt (II) and other metals complexed to these tripodal ligands have been prepared, and show activity that mimics the CAH catalytic process–hydration of CO2 to bicarbonate followed by the reverse dehydration of the bicarbonate to regenerate CO2 in a pH dependent mechanism. The thermal stability of these complex catalysts has been demonstrated by Differential Thermo-Gravimetric (DTG) studies to above 200 °C. A process for fast absorption/desorption is proposed.

Abstract The paper presents an equivalent circuit based simulation model for the static and dynamic behavior of lithium-ion battery systems and explains the different steps of the theoretical and experimental modeling process. The equivalent circuit based model describes the voltage-current characteristic, the state of charge behavior and the occurring losses of the battery system. A parameter identification method based on three characteristic experiments, a cycle test, an open circuit voltage test and pulse tests, is introduced. The model parameters are estimated employing a nonlinear optimization method. Furthermore, the experimental test bed for investigation of lithium-ion battery systems is described. The battery model approach is demonstrated and validated for a commercial 5 kWh lithium-ion battery system, including the model validation for test profiles and emulated battery charging and discharging profiles of a real photovoltaic home storage application. The comparison of measured and simulated voltage profiles indicates an excellent performance of the battery model.

AbstractPyrochemical methods for reprocessing of spent nuclear fuel are under development as an alternative to the hydrometallurgical processes. The pyrochemical reprocessing process developed in ITU is based on electrorefining of spent fuel in molten LiCl-KCl salt using solid aluminium cathodes. This is followed by a chlorination process for the recovery of actinides from the actinide-aluminium alloys formed and exhaustive electrolysis is proposed for clean-up of the salt from the remaining actinides. In this paper, all investigated techniques are described and the main achievements are summarised. The emphasis is given to the electrorefining, which represents the core process for homogeneous recovery of all actinides from the spent fuel. High efficiency of the process and excellent recovery of actinides over lanthanides have been achieved and very high capacity of solid aluminium to take up actinides has been demonstrated.

Abstract Commonly, wake models are calibrated in wind tunnels or using flow simulations with a wide degree of physical details. In general, it is assumed that these methods cannot fully reproduce the real operating conditions of wind turbines. This research aims at investigating the calibration of an analytical single wake model in relation to full-scale measurements. Within this scope, we fitted the wake model to wake measurements realised with a lidar installed on the nacelle of an offshore wind turbine. We studied the parameters returned by the fit separating cases at different levels of atmospheric turbulence and thrust on the wind turbine rotor. Comparing the results with a published calibration based on few LES wind fields representative for partial load conditions, we achieved good agreement when the considered wind turbines operated in similar conditions. For other situations, i.e. at full load, we found different calibrations of the model parameters. Our results show that and how nacelle-based lidar measurements can be complementary in the development of wake models.

AbstractOne of the advantages of solar thermal power plants (STPPs) with molten salt as heat transfer fluid is the direct storage system. This means that the thermal energy collected by the solar field and the electric power generation can be fully decoupled. The plant operator must therefore make the daily decision when to start-up or to shut-down the power block (PB). Normally, the solar field of these STPPs is overdesigned which leads to dumping of solar energy during days with high solar radiation, due to the inability of the hot tank and the PB to consume all the collected thermal energy. The PB must therefore start as soon as possible to prevent excessive dumping of solar energy. Contrarily, on days with low solar radiation, the PB should not start too early to prevent a second start-up on this day, because of a low hot tank level. In order to operate within these counter bounds, a fixed and a dynamic operation strategy are proposed. The so-called solar-driven strategy serves as a reference. Using this strategy, the PB operates whenever the solar field is online. The two proposed operation strategies are compared to the reference strategy by means of a transient STPP simulation model. Using the dynamic operation strategy, the annual unnecessary PB start-ups and the auxiliary heater thermal energy for anti-freeze protection are decreased, whereas the annual net electricity is increased.

Abstract Light-induced plating (LIP)of Ni/Cu presents a potentially lower-cost alternative to screen-printed Ag for silicon solar cell metallization. This paper presents results of self-annealing and post-plating rapid thermal processing (RTP) of plated Cu finger microstructure, texture and resistance. It is shown that the plated Cu conductors, if not thermally-annealed immediately after plating, self-anneal with time resulting in grain growth and increased (200) to (111) grain texture which occurs with increased tensile stress. Post-plating RTP annealing enables fast annealing and stable Cu fingers with a low ratio of (200) to (111) grain texture. These findings have important implications for plated finger adhesion and highlight the importance of annealing after plating for reliable Cu plated metallization.

AbstractEvaporation cooling systems are currently deployed in the majority of operating Concentrating Solar Power (CSP) plants. However, the fundamental drawback of this approach is that large quantities of water are used in the cooling tower, so that this solution will be not applicable for a large-scale CSP development in arid regions. In fact, in most of the sites suitable for CSP applications, ambient temperatures are typically high and water is scarcely available, or the cost of transporting water to these sites is prohibitive. For this reason, at these sites dry cooling will be the only viable option. This paper analyses the impact of dry cooling systems on technical and economic plant performances, considering several condenser layouts, different operation strategies and economic boundary conditions. In particular, the capacity and the operation of the thermal energy storage can be optimized in order to maximize power production, e.g. by preferential plant commitment at night hours. The analysis is carried out for three selected locations with real meteorological data by means of annual simulations with hourly time steps.