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Goncalves M.R.,Omnidea Lda | Gomes A.,Omnidea Lda | Gomes A.,University of Lisbon | Condeco J.,Omnidea Lda | And 5 more authors.
Electrochimica Acta | Year: 2013

The electrodeposition of copper on copper electrodes was used to increase the copper active surface area available for the electrochemical conversion of CO2 to C2 hydrocarbons and to study the dependence of the reaction on the electrode structure. Different electrodes were developed with dendritic, honeycomb and 3D foam structures and were employed for the reduction process at -1.9 V vs. Ag/AgCl in the presence of KHCO3 0.1 mol dm-3. The hydrocarbons C2H4 and C 2H6 are formed in the presence of honeycomb-like and foam structures, whilst CH4 formation is suppressed and it was concluded that the structure of the copper electrodeposits has a major effect on the electrochemical conversion of CO2. Additionally, it was found that the less negative the cathodic potential applied (in the range of -1.5 to -1.9 V vs. Ag/AgCl), or the lower the electrolyte concentration (0.03 vs. 0.1 mol dm-3), the greater is the increase in the amount of ethane. © 2013 Elsevier Ltd. All rights reserved.

Goncalves M.R.,Omnidea Lda | Gomes A.,Omnidea Lda | Condeco J.,Omnidea Lda | Fernandes R.,Omnidea Lda | And 3 more authors.
Energy Conversion and Management | Year: 2010

A novel approach for the conversion of CO2 by an electrochemical process has been achieved using copper electrodes modified with electrodeposits. The presence of the electrodeposits changes the catalytic behaviour of the substrates, since a hydrocarbons mixture with higher energetic density per volume is achieved when compared with the fuel resulting from CO2 reduction without electrodeposits. In these electrodes, ethylene is selectively produced in detriment of methane. Additionally, the formation of a mixture of C2 hydrocarbons (C2H4 and C2H6) without C1 hydrocarbons is successfully obtained on specific higher surface area electrodeposits. Furthermore, it is confirmed that the presence of the electrodeposits lead to steadiness of the CO2 reduction process, since it is established the stability of hydrocarbons production during 4 h. © 2009.

Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: NMP.2012.2.1-2 | Award Amount: 3.51M | Year: 2013

CEOPS project will focus on a sustainable approach for the production of methanol from CO2, which is a precursor for fine chemicals products. The approach will reinforce the link between large CO2 emitters and fine chemical industries at the European level. The concept relies on two chemical pathways, CO2 to CH4 and CH4 to CH3OH with the intermediate carbon vector: methane. Methane benefits from the extended and existing natural gas network infrastructure. Its distribution will prevent additional CO2 emissions (rail & road transportation). This approach will favour the emergence of small and flexible production units of fine chemicals from methanol. The technological work is based on advanced catalysts and electro-catalytic processes. CEOPS will develop advanced catalysts for application in three promising electro-catalytic processes (Dielectric barrier discharge plasma catalysis, Photo-activated catalysis and Electro-catalytic reduction) to increase their efficiency overtime for both pathways. The performances of the studied catalyst and process schemes will be benchmarked and the most efficient one, for each pathway, will be selected for a prototype. This prototype will be realised at a scale of 3m3.h-1 of methane, it will validate the concept and generate the required data for the techno-economic assessment. The consortium merges the skills of 2 research organisations, 3 universities, 1 SME, 1 non profit organisation, 2 industries and 1 cluster. The project is led by CEA-LITEN. Italcementi, GSER and CCB will bring respectively their expertise in CO2 emissions, CH4 injection and transportation and on methanol use for the fine chemical industry. They also contribute to the techno-economic and environmental assessments. IST, IREC, OMNIDEA will develop advanced catalysts. UPMC, CEA, IREC, NOVA will develop electro-catalytic processes. CEA assisted by the consortium will implement the prototype. EMSR and CCB will ensure the dissemination of the CEOPS concept and results.

Agency: Cordis | Branch: FP7 | Program: CP | Phase: ENERGY.2010.10.2-1 | Award Amount: 2.94M | Year: 2010

The quest for clean and renewable energy sources found tremendous potential in wind power. So far, it has been harvested mostly by wind towers, which use only wind currents close to the ground (bellow 200m of height). Since low altitude wind currents are slow and intermittent, most wind farms operate, on average, 25-35% of their capacity. This represents a severe limitation to current state-of-art wind power technology, as towers can hardly be taller than 130m without prohibitive costs and insurmountable technical difficulties. To bypass these difficulties, it is proposed to perform R&D in a multitude of technology fields such as materials, aerodynamics and control, further developing a wind power system capable of harnessing the energy potential of high altitude wind without the need for heavy towers or expensive elevated nacelles: we call it HAWE (High Altitude Wind Energy). HAWE consists of a buoyant, rotating, cylinder shaped, airship, anchored to a ground station by a tether cable operating a two phase cycle. During the power production phase the Magnus effect on the rotating cylinder generates lift, pulling up the tether cable which, at the ground station, is in a winch drum driving a flywheel connected to an alternator producing electricity. When the tether cable is fully unwound, the recovery phase starts - as the cylinder rotation ceases and the cable is reeled back to its initial position decoupled from the flywheel, completing a cycle. This is performed continuously. The successful implementation of this concept will increase the share of renewable energy in Europe since, the achievement of the goal to produce renewable energy at competitive prices with coal derived energy, should lower its cost. A high security of supply, a cleaner environment, and the possibility to keep Europe as a global leader in wind power, are other benefits of this technology.

Ban M.,University of Zagreb | Perkovic L.,University of Zagreb | Duic N.,University of Zagreb | Penedo R.,Omnidea Lda
Energy | Year: 2013

High altitude winds are considered to be, together with solar energy, the most promising renewable energy source in the future. Till date, there are no yet solutions available on the market but various concepts for utilizing high altitude winds are under research and are expected to be fully operational within next few years.In this paper, the potential of high altitude wind energy will be investigated for the SEE (Southeast Europe) region and mapped using available data and technologies. The data available from NCEP/DOE analysis will be used in terms of obtaining the high altitude wind speeds for the span of 30 years, from 1980 to 2010, which are then processed for easier visualization. The obtained data is plotted against the available geographic data which could limit the positioning of the system (settlements, traffic. .). The result of this work will display the "optimal" locations for these kinds of facilities for the Southeast Europe region. Such map could be beneficial for all future plans of utilizing this high altitude winds as a power source. © 2013 Elsevier Ltd.

Perkovic L.,University of Zagreb | Silva P.,Omnidea Lda | Ban M.,University of Zagreb | Kranjcevic N.,University of Zagreb | Duic N.,University of Zagreb
Applied Energy | Year: 2013

High altitude winds are considered to be, together with solar energy, the most promising renewable energy source in the future. The concepts based on kites or airfoils are already under development. In this paper the concept of transforming kinetic energy of high altitude winds to mechanical energy by exploiting Magnus effect on airborne rotating cylinders is presented, together with corresponding two-dimensional per-module aerodynamic and process dynamics analysis. The concept is based on a rotating airborne cylinder connected to the ground station with a tether cable which is used for mechanical energy transfer. Performed studies have shown the positive correlation between the wind speed and mechanical energy output. The main conclusion of this work is that the presented concept is feasible for power production. © 2012 Elsevier Ltd.

Reis Machado A.S.,Omnidea Lda | Fernandes T.R.C.,Omnidea Lda | Pardal T.,Omnidea Lda | Rangel C.M.,Fuel Cells and Hydrogen Unit Paco do Lumiar
Materials Science Forum | Year: 2013

Direct electrochemical reduction of CO2 is a process that could contribute to the reduction of the emission of greenhouse gases by using CO2 as a raw material for fuel production. This paper focuses on voltammetric studies of functionalized electrodes for the electrochemical conversion of CO2 and reports on its use as a tool for electrode screening and optimization. Nickel substrates modified with copper and ruthenium/copper electrodeposits were studied. Voltammetric experiments indicate that CO2 electroreduction follows a nickel type mechanism in which this electrochemical reaction occurs simultaneously and in competition with hydrogen evolution. A significant inhibition of hydrogen evolution reaction is observed in nickel modified electrodes. Inhibition characteristics and the onset of carbon dioxide conversion are dependent of the type of electrode functionalization. Voltammetry is thus a powerful tool to evaluate electrode modifications and for tuning electrodes for an optimized electrocatalytic performance. © (2013) Trans Tech Publications, Switzerland.

Omnidea Lda. | Date: 2012-03-15

The invention pertains to aeronautical engineering and consists of an airborne platform that can be built to large sizes without requiring a rigid structure of comparable dimensions and which uses both buoyancy and the aerodynamic Magnus effect for lift. The aerodynamic lift is generated in lifting bodies (1), which also contain buoyant gas. The lifting bodies (1) are stacked in a column, at the bottom of which there is a structural anchoring module (2) which also contains buoyant gas. The lifting bodies (1) and anchoring modules (2) are connected by slender structural elements which, when taken together as a whole form a non-rigid assembly. The platform may be tethered or configured as an aircraft, for which purpose other features may be added, such as a propulsion system (11), a crew gondola (6), cables to (7) and from (8) a swivel (12) and a payload (10) connected to said cables.

Omnidea Lda. | Date: 2011-07-06

The invention herein described consists of a system destined to harness wind resources, transferring either: winds momentum into aerodynamic force that can be used directly in case the system is working as a high altitude platform; or wind power to the ground station group on the surface, the process being performed through the tensioning and unwinding of the cable group connecting the airborne group to a reeler in the said ground station group.Through the control group the resultant force vector of the aerodynamic forces tensioning the cable can be significantly altered.

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