ES - Comunicações orais em encontros científicos
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- 3DOM ceria ecoceramics from sustainable cork templates for solar thermochemical CO2 splittingPublication . Pullar, Robert C.; Novais, Rui M.; Caetano, Ana P. F.; Barreiros, M. Alexandra; Abanades, Stéphane; Almeida Costa Oliveira, Fernando
- Reverse osmosis powered by concentrating solar power (CSP): a case study for Trapani, SicilyPublication . Ahmed, Mahran K. A.; Cardoso, João P.; Mendes, J. Farinha; Casimiro, SergioThe objective of this paper is to analyse the physical performance of two technologies in a water and electricity co-generation scheme: Concentrated Solar Power (CSP) plant coupled to a Reverse Osmosis (RO) unit for a location in the city of Trapani, in southern Italy. The modelled system is compared with the results of another study [2], in which a Multi-Effect Desalination (MED) is powered by a CSP plant for the same location in Italy, using as reference an existing stand-alone gas powered MED plant located at Trapani [3] (which has operated until very recently). The overall aim is to assess and compare these two cogeneration schemes, using as reference the existing MED plant. This work was conducted using as the main simulation tool: the System Advisor Model (SAM) developed by the US National Renewable Energy Laboratory (NREL); a recent upgrade to SAM made available to this work through Laboratório Nacional de Energia e Geologia I.P. (LNEG); and the Reverse Osmosis System Analysis (ROSA) developed by the Dow Chemical Company. A technical visit to a real commercial RO plant in the south of Portugal (Alvor) was conducted, and the data gathered was used in the validation of the ROSA model. The results for the Trapani case study show that the CSP-RO arrangement has the capability to produce ~50% of the total production of the full scale plant at Trapani, if operated at nominal capacity, year round. Also, the CSP-RO system provides ~20% more electricity and water than the CSP-MED system throughout the studied period of one year. The two co-generation schemes provide promising potential to fight the issues related to fresh water shortages and dependency on fossil fuelled desalination. Thus, they can aid in decreasing the effects associated with CO2 emissions and climate change.
- Harnessing the sun: concentrated solar power [Comunicação oral]Publication . Cardoso, João P.
- Assessment of dye distribution in sensitized solar cells by microprobe techniques [Comunicação oral]Publication . Barreiros, M. Alexandra; Corregidor, V.; Alves, L. C.; Guimarães, Fernanda; Sequeira, S.; Mascarenhas, João; Torres, Erica; Brites, Maria JoãoDye sensitized solar cells (DSC’s) have received considerable attention once this technology offers economic and environmental advantages over conventional photovoltaic (PV) devices. A DSC photoanode typically consists of a nanocrystalline porous TiO2 film, endowed with a large adsorptive surface area. Dye molecules that capture photons during device operation are attached to the film nanoparticles. The effective loading of the dye in the TiO2 electrode is of paramount relevance for controlling and optimizing solar cell parameters. In particular, the cell shortcircuit current density (Jsc) is directly proportional to the light harvesting ability of the photoanode, which in turn is strictly dependent on the dye concentration on the TiO2 adsorptive surface. In addition, the dye adsorption behavior affects the cell open circuit voltage (Voc). Relatively few methods are known today for quantitative evaluation of the total dye adsorbed in the film. In this context microprobe techniques come out as suitable tools to evaluate the dye distribution and dye depth profile in sensitized films. Electron Probe Microanalysis (EPMA) and Ion Beam Analytical (IBA) techniques using a micro-ion beam were used to quantify and to study the distribution of the ruthenium organometallic (N719) dye in TiO2 films, making use of their different penetration depth and beam sizes. Two different types of films were prepared and sensitized, mesoporous nanoparticles and 1D nanostructured TiO2 films (about 4 ìm thickness). The high sensitive analytical techniques used allowed to assess dye surface distribution and depth profile, by means of Ru signal, despite the low concentration of this element. X-ray mapping by EPMA/WDS technique made possible to visualise the dye distribution in sample cross-section. PIXE maps of Ru and Ti indicated an homogeneous surface distribution. The assessment of ruthenium depth profile by RBS showed that some films have homogeneous Ru depth distribution while others presented up to half of the Ru concentration in the top layer (2 ìm thickness) when compared to the lower one. Dye load evaluation in different TiO2 films by two different techniques (ìPIXE and EPMA/WDS) provided similar results of Ru/Ti. The assessment of the dye distribution and quantification across an oxide semiconductor film by microprobe techniques can lead to a better understanding of the device performance.
- Cork, energetic and environmental aspectsPublication . Gil, Luís
- Aplicações com concentração solarPublication . Mendes, J. Farinha
- Energia solar térmica e desenvolvimento ruralPublication . Mendes, J. Farinha
- Aproveitamento da energia solar térmica: centrais solares termoeléctricasPublication . Cardoso, João P.
- Aproveitamento da energia solar térmica em PortugalPublication . Cardoso, João P.; Mendes, J. Farinha
- Energia solar térmicaPublication . Mendes, J. Farinha; Cardoso, João P.