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Off-design operation of coal power plant integrated with natural gas fueled molten carbonate fuel cell as CO2 reducer
No full textThe paper presents an experimental investigation of a Molten Carbonate Fuel Cell (MCFC) fueled by methane in order to predict how to reduce CO2 emissions from the flue gas of a real power plant. MCFCs can be placed in the flue gas stream of a fossil fired power plant to separate CO2 by transferring it from the cathode side to the anode side. As a result, a mixture of CO2 and H2O is separated from which pure CO2 can be obtained through condensation of water. The main advantages of this solution are: additional power generation, reduced CO2 emissions and higher system efficiency. Furthermore, coal plants seem to be the ideal candidate to retrofit with MCFC plant due to their high exhaust CO2 content and to the low cost of the fuel that encourages its application despite the narrower emission requirement. The experimental results show that use of an MCFC could reduce CO2 emissions by 90% with over 30% efficiency in additional power generation and by demonstrating a broad range of different operative conditions
Investigating Sustainable Materials for AEM Electrolysers: Strategies to Improve the Cost and Environmental Impact
No full textIn recent years, the EU policy identified the hydrogen as one of the main energy vectors to support the power production from renewable sources. Coherently, electrolysis is suitable to convert energy in hydrogen with no carbon emission and high purity level. Among the electrolysis technologies, the anion exchange membrane (AEM) seems to be promising for the performance and the development potential at relatively high cost. In the present work, AEM electrolysers, and their technological bottlenecks, have been investigated, in comparison with other electrolysers’ technology such as alkaline water electrolysis and proton exchange membranes. Major efforts and improvements are investigated about innovative materials design and the corresponding novel approach as main focus of the present review. In particular, this work evaluated new materials design studies, to enhance membrane resistance due to working cycles at temperatures close to 80 °C in alkaline environment, avoiding the employment of toxic and expensive compounds, such as fluorinated polymers. Different strategies have been explored, as tailored membranes could be designed as, for example, the inclusion of inorganic nanoparticles or the employment of not-fluorinated copolymers could improve membranes resistance and limit their environmental impact and cost. The comparison among materials’ membrane is actually limited by differences in the environmental conditions in which tests have been conducted, thereafter, this work aims to derive reliable information useful to improve the AEM cell efficiency among long-term working periods
Dimethyl sulfide adsorption from natural gas for solid oxide fuel cell applications
No full textThe use of solid oxide fuel cell (SOFC) systems in micro-CHP applications is of great interest because of high efficiency, low emissions and absence of noise. However, SOFCs are sensitive to degradation caused by organic sulfur compounds present in natural gas or added as odorants. Among them, dimethyl sulfide (DMS) is one of the sulfur species most resistant to purification treatments and, relative to DMS removal, a lack in literature is highlighted for the investigated application.
Regarding adsorption technology, the present work deals with an organic sensitivity performance analysis of different commercial sorbents. Virgin and impregnated activated carbons and a natural zeolite were tested, varying gas hourly space velocity, reactor geometry and filter assembly. Because of differences in activity towards DMS exhibited by the investigated materials, to exploit their selectivity, also layered sorbents were realized and tested.
Starting from resulting data, for the yearly operation of 1 kWel SOFC-based micro-CHP system, an optimization of filter assembly (also considering multi-layered configurations) and operative conditions was performed, leading to a strong reduction in filter volume (up to five times) and cost (more than three times), with overall pressure drops compatible with pipeline gas distribution pressure
Carbon capture with molten carbonate fuel cells: Experimental tests and fuel cell performance assessment
No full textMolten carbonate fuel cells (MCFCs) may operate as CO2 separators and concentrators while generating electric power, being thus a very interesting candidate to be used as carbon capture systems in fossil fired power plants.The main aim of this work is to understand the MCFC performance, its potential and efficiency to separate CO2 from the exhaust gas of fossil fired power plants and the effect of critical parameters such as the cathodic carbon dioxide concentration (XCO2) and utilization (UCO2), as well as the partial pressure ratio between oxygen and carbon dioxide (PO2/PCO2) and other parameters such as the oxygen concentration (XO2), utilization (UO2) and the total cathodic flow rate (Qcat). This was achieved by studying the experimental behaviour of a single MCFC when it is fed with a mixture simulating the composition of the exhaust gases of a combined heat and power plant, in order to point out potential limitations in the fuel cell operating conditions.In particular, the carbon dioxide concentration in the cathodic section was shown to be a critical factor at low values, that can both induce quick voltage drops and make the cell sensitive to the other parameters, which are otherwise not so important
Developing Tailored Materials for the Industrial Production of Anion Exchange Membrane Electrolyzers through a Statistical Approach
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