SIMULATION OF FLUIDIZED BED SORPTION-ENHANCED METHANATION
| Autor: | A. Coppola, G. Ferraro, F. Massa, F. Scala |
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| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: | |
| Zdroj: | 43rd Meeting of the Italian Section of the Combustion Institute, Ischia, 04/10/2021-07/10/2021 info:cnr-pdr/source/autori:A. Coppola*, G. Ferraro**, F. Massa**, F. Scala*,**/congresso_nome:43rd Meeting of the Italian Section of the Combustion Institute/congresso_luogo:Ischia/congresso_data:04%2F10%2F2021-07%2F10%2F2021/anno:2021/pagina_da:/pagina_a:/intervallo_pagine |
| Popis: | Methane is a crucial energy carrier with a massive use in all sectors and a well-developed distribution and storage infrastructure. In the framework of the efforts made to address the energy transition, it is of great interest the replacement of fossil methane by its synthetic alternative, the Substitute Natural Gas, coming from renewable sources. The reactants (CO/CO2 and H2) for catalytic methanation can be obtained from different pathways involving renewable sources: they could derive, for example, from biomass-produced syngas or from generated H2, exploiting the surplus of renewable electricity to perform water electrolysis, and CO2, which can be a pure captured stream, thus giving a Carbon Capture and Utilization solution. The studies on catalytic methanation have recently been developed with the concept of sorption-enhanced reaction, using a proper sorbent material to adsorb the water produced by the reactions, in order to enhance the equilibrium conditions even at low pressures. The aim of this work was to analyze the Sorption Enhanced Methanation (SEM) in a Dual Fluidized Bed system at 300°C and 1 atm, by selecting CaO as water sorbent and using as simulator Aspen Plus®V10 software. The process was mainly analyzed under stoichiometric conditions, introducing dimensionless parameters to consider different relative quantities of CO and CO2 fed, and different amounts of CaO compared to the stoichiometric one to capture all the generated H2O. The purity of the methane is a sensitive aspect to assess, given the restrictions for injection in the grid, in particular with regard to the percentage of admissible H2. SEM results on the outlet composition showed that H2 on dry basis was never low enough to be fed directly into the grid. The undesired carbonation of CaO was found to be the main reason for this behavior. This secondary reaction seems to be able, by absorbing CO2, to shift the equilibrium of important involved reactions towards the consumption of the methane itself, and the production of H2. To fulfill the limits for injection, another kind of sorbent, not subject to carbonation and already being studied, may be selected, e.g. a zeolite, acting as molecular sieve and giving water selective adsorption. Another interesting condition to be verified may be to evaluate non-stoichiometric conditions, and in particular when H2 is the limiting reactant. |
| Databáze: | OpenAIRE |
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