Search results for "varastointi"
showing 10 items of 11 documents
Hajautetun energiajärjestelmän toteutusmahdollisuudet virtausakkuteknologialla
2016
Työssä tutkittiin virtausakkuteknologian soveltuvuutta osana hajautetun energiajärjestelmän toteutusta. Hajautettu virtausakku on laaja energiaverkosto, joka mahdollistaa energiansiirron ja -varastoinnin. Energia varastoidaan virtausakun elektrolyyttiin, jota säilytetään kaukolämpöverkoston kaltaisessa laajassa putkiverkostossa. Elektrolyyttiä siirretään putkiverkostossa maan alla pumppaamalla ja hajautetun akun lataaminen ja purkaminen suoritetaan tuotannon ja kulutuksen yhteydessä kennopinojen välityksellä. Tutkimus keskittyi hajautetun virtausakun soveltuvuuteen uusiutuvan energian varastoinnissa sekä kulutuksen teho-optimointiin huipunleikkauksessa. Tutkimusta varten ohjelmoitiin Matlab…
Methane and hydrogen production from crop biomass through anaerobic digestion
2011
Water-use efficiency and transpiration across European forests during the Anthropocene
2015
Considering the combined effects of CO2 fertilization and climate change drivers on plant physiology leads to a modest increase in simulated European forest transpiration in spite of the effects of CO2-induced stomatal closure. The Earth’s carbon and hydrologic cycles are intimately coupled by gas exchange through plant stomata1,2,3. However, uncertainties in the magnitude4,5,6 and consequences7,8 of the physiological responses9,10 of plants to elevated CO2 in natural environments hinders modelling of terrestrial water cycling and carbon storage11. Here we use annually resolved long-term δ13C tree-ring measurements across a European forest network to reconstruct the physiologically driven r…
Use of nanostructures as oxygen carriers in chemical looping combustion
2013
The usage of fossils fuels has increased carbon dioxide emissions, and the carbon dioxide is responsible for global warming and sea level rising. One of the most promising ways of carbon capturing from the power plants is chemical looping combustion (CLC). CLC is based on the alternating oxidation and reduction reactions on the air and fuel reactors. Oxygen and energy needed for combustion between the reactors is transferred by an oxygen carrier. Oxygen carrier is usually made of metal or metal oxide. One big hindrance towards commercial use of CLC is slow reaction kinetics of oxygen carriers. One possible solution for the problem is to replace the conventional carriers by nanoscale oxygen …
Influence of a Cu–zirconia interface structure on CO2 adsorption and activation
2021
CO2 adsorption and activation on a catalyst are key elementary steps for CO2 conversion to various valuable products. In the present computational study, we screened different Cu–ZrO2 interface structures and analyzed the influence of the interface structure on CO2 binding strength using density functional theory calculations. Our results demonstrate that a Cu nanorod favors one position on both tetragonal and monoclinic ZrO2 surfaces, where the bottom Cu atoms are placed close to the lattice oxygens. In agreement with previous calculations, we find that CO2 prefers a bent bidentate configuration at the Cu–ZrO2 interface and the molecule is clearly activated being negatively charged. Strain…
Computational studies of chemical looping combustion materials and CO₂ activating surfaces
2016
Recent progress in metal-organic frameworks (MOFs) for CO2 capture at different pressures
2022
Global climate change ensued by the rise in atmospheric CO2 levels is one of the greatest challenges our planet is facing today. This worldwide distress demands technologies that can contribute to our society toward “negative carbon emissions”. Carbon capture and storage (CCS) technologies are in in important role for capturing CO2 from existing emission sources, such as industrial and energy production point sources, before new more prominent modifications to the energy infrastructure can be implemented. Recently, alongside point source capture, direct air capture (DAC) processes have emerged as highly sought-after technologies that are able to capture CO2 from the ambient air. Alongside t…
Analysis of 5 MW hydrogen power system with thermal energy storage
2013
Energy storage for further energy production has become a feasible option to deal with energy fluctuation, energy over production and energy shortcomings caused by the penetration of renewable energies. Hydrogen storage has been studied through mathematical model and simulation to predict its performance and technological feasibility. This thesis presents a model where a 5 MW electrolysis plant is simulated. The power plant consists on an electric input from renewable sources like wind turbines or photovoltaic panels. Electrolysis is done by a solid oxide cell that also produces electric power working as fuel cell. Thermal energy storage is added in order to recover heat released by the cel…