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Multi-scale modelling and simulation of Ca-looping cycle process for CO2 post-combustion capture
Anton Friedl, Jiří J. Klemeš, Stefan Radl, Petar S. Varbanov, Thomas Wallek (Eds.) Proceedings of the 28th European Symposium on Computer Aided Process Engineering June 10th to 13th, 2018, Graz, Austria. © 2018 Elsevier B.V. All rights reserved. https://doi.org/10.1016/B978-0-444-64235-6.50053-X
Multi-scale modelling and simulation of Ca-looping cycle process for CO2 post-combustion capture Carla I.C. Pinheiroa, Rui Filipeb, Miguel Abreu Torresa, João M. Silvab, Henrique A. Matosa a
Instituto Superior Técnico, Universidade de Lisboa, PT
b
Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, PT
[email protected]
Abstract The present work focuses on one of the more promising new post-combustion technologies using calcium-based materials, known as the “Ca-looping cycle” process, which endeavors to scrub CO2 from flue gases and syngases by using natural lime-based sorbents and which appears to potentially offer limited CO2 capture costs. So, the major driving force is to improve overall efficiency, reduce the cost, and minimize adverse environmental impacts of post-combustion Ca-looping cycle CO2 capture, as compared to more conventional technologies (e.g., amine-based solvent scrubbing). There is a large energy penalty with amine scrubbing, the closest to market technology. The main objective of this work is to develop a first principles model to simulate different natural sorbents looping cycle performance in a fixed bed reactor laboratory scale system. A rigorous non-linear dynamic model of the looping cycle process was developed in gPROMS, based on the multiscale concept. The multiscale modeling is an emerging technique, where the characteristic length for each phenomena that occurs is taken into consideration, leading to a set of submodels with different scale lengths. These submodels when coupled together allow the simulation of a macrosystem (Hangos and Cameron, 2001). After the identification of the characteristic dimensions involved in the models, the first step is the development of a single particle model, which takes into account the energy and material transport, undergoing reactions (carbonation and calcination) and structural changes inside the particle. The material and heat transport inside the particle take into account the structural changes. Detailed models of single particle undergoing cycles of calcination and carbonation are developed. An improved decay approach is introduced in the model for those sorbents exhibiting carbonation decay with the number of cycles. The experimental characterization of the samples gave vital information on the physicochemical changes occurring during testing that need to be described in the model in the carbonation decay function. The conversion decay does not only depend on the number of cycles, but also on the conditions of the previous cycles, temperature, pressure, gas phase composition and characteristics of the material used for the carbonation. Model parameters are estimated from experimental results obtained for different sorbents tested (Santos et al., 2012)(Pinheiro et al., 2016). Several simulations for different sorbents and operating conditions were performed and the
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model was validated with experimental data obtained in a fixed bed reactor. It was also important to ensure that the model is numerically stable within a large range of values. Keywords: simulation, CO2 capture, Calcium Looping, Carbon emissions reduction, Multi-scale modelling
Acknowledgement The authors gratefully acknowledge the financial support by the Portuguese Foundation for Science and Technology (Fundação para a Ciência e Tecnologia), through Research Projects Nos. UID/QUI/00100/2013 and PTDC/AAG-MAA/6195/2014.
References K.M. Hangos, I.T. Cameron, "Process modelling and model analysis", Academic Press, 2001. E.T. Santos, C. Alfonsin, A.J.S. Chambel, A. Fernandes, A.P.S. Dias, C.I.C. Pinheiro, and M.F. Ribeiro, “Investigation of a stable synthetic solgel CaO sorbent for CO2 capture”, Fuel, vol. 94, pp.624-628, 2012. C.I.C. Pinheiro, A. Fernandes, C. Freitas, E.T. Santos, and M.F. Ribeiro, "Waste Marble Powders as Promising Inexpensive Natural CaO-Based Sorbents for Post-Combustion CO2 Capture", Ind. Eng. Chem. Res., vol.55, pp.7860−7872, 2016.
Multi-scale modelling and simulation of Ca-looping cycle process for CO2 post-combustion capture Carla I.C. Pinheiroa, Rui Filipeb, Miguel Abreu Torresa, João M. Silvab, Henrique A. Matosa a
Instituto Superior Técnico, Universidade de Lisboa, PT
b
Instituto Superior de Engenharia de Lisboa, Instituto Politécnico de Lisboa, PT
[email protected]
Abstract The present work focuses on one of the more promising new post-combustion technologies using calcium-based materials, known as the “Ca-looping cycle” process, which endeavors to scrub CO2 from flue gases and syngases by using natural lime-based sorbents and which appears to potentially offer limited CO2 capture costs. So, the major driving force is to improve overall efficiency, reduce the cost, and minimize adverse environmental impacts of post-combustion Ca-looping cycle CO2 capture, as compared to more conventional technologies (e.g., amine-based solvent scrubbing). There is a large energy penalty with amine scrubbing, the closest to market technology. The main objective of this work is to develop a first principles model to simulate different natural sorbents looping cycle performance in a fixed bed reactor laboratory scale system. A rigorous non-linear dynamic model of the looping cycle process was developed in gPROMS, based on the multiscale concept. The multiscale modeling is an emerging technique, where the characteristic length for each phenomena that occurs is taken into consideration, leading to a set of submodels with different scale lengths. These submodels when coupled together allow the simulation of a macrosystem (Hangos and Cameron, 2001). After the identification of the characteristic dimensions involved in the models, the first step is the development of a single particle model, which takes into account the energy and material transport, undergoing reactions (carbonation and calcination) and structural changes inside the particle. The material and heat transport inside the particle take into account the structural changes. Detailed models of single particle undergoing cycles of calcination and carbonation are developed. An improved decay approach is introduced in the model for those sorbents exhibiting carbonation decay with the number of cycles. The experimental characterization of the samples gave vital information on the physicochemical changes occurring during testing that need to be described in the model in the carbonation decay function. The conversion decay does not only depend on the number of cycles, but also on the conditions of the previous cycles, temperature, pressure, gas phase composition and characteristics of the material used for the carbonation. Model parameters are estimated from experimental results obtained for different sorbents tested (Santos et al., 2012)(Pinheiro et al., 2016). Several simulations for different sorbents and operating conditions were performed and the
292
C.I.C. Pinheiro et al.
model was validated with experimental data obtained in a fixed bed reactor. It was also important to ensure that the model is numerically stable within a large range of values. Keywords: simulation, CO2 capture, Calcium Looping, Carbon emissions reduction, Multi-scale modelling
Acknowledgement The authors gratefully acknowledge the financial support by the Portuguese Foundation for Science and Technology (Fundação para a Ciência e Tecnologia), through Research Projects Nos. UID/QUI/00100/2013 and PTDC/AAG-MAA/6195/2014.
References K.M. Hangos, I.T. Cameron, "Process modelling and model analysis", Academic Press, 2001. E.T. Santos, C. Alfonsin, A.J.S. Chambel, A. Fernandes, A.P.S. Dias, C.I.C. Pinheiro, and M.F. Ribeiro, “Investigation of a stable synthetic solgel CaO sorbent for CO2 capture”, Fuel, vol. 94, pp.624-628, 2012. C.I.C. Pinheiro, A. Fernandes, C. Freitas, E.T. Santos, and M.F. Ribeiro, "Waste Marble Powders as Promising Inexpensive Natural CaO-Based Sorbents for Post-Combustion CO2 Capture", Ind. Eng. Chem. Res., vol.55, pp.7860−7872, 2016.