Dominating dynamics of the post-combustion CO2 absorption process

Abstract A dynamic model of the post-combustion CO 2 capture process based on chemical absorption is used to investigate the transient behavior and dynamic responses of the process and to detect stabilization time when various disturbances are introduced. Plant dimensions and parameter settings are based on the SINTEF CO 2 capture pilot plant at Tiller in Norway, and the overall process model is validated using two sets of steady state pilot plant data. A deviation between model and pilot plant results of −0.8% and −4.5% in absorbed CO 2 and 2.6% and 1.2% in desorbed CO 2 is seen for the two cases used in validation, respectively, which is within the observed pilot plant CO 2 mass balance error of ±6%. The simulated absorber and desorber temperature profiles show also adequate agreement to the pilot plant measurements. The process model is further used to simulate set-point changes in flue gas flow rate, reboiler duty and solvent flow rate in order to investigate typical stabilization times at various locations in the process. As expected, mixing models such as the absorber sump and reboiler will introduce time constants that affect the dynamic response profiles, while plug flow models such as the cross heat exchanger and lean cooler causes pure transport delays and no additional settling time. Mass transfer and chemical reaction rates causes some process inertia, but it is relatively small compared to the inertia of larger mixing vessels such as the absorber sump, reboiler and buffer tank and transport delay caused by plug flow. Changes to the solvent flow rate are also seen as a larger disturbance to the process compared to changes in flue gas flow rate and reboiler duty, reflected by longer process stabilization time to reach new steady state conditions. The estimated 90% settling times for the response in CO 2 capture rate in the Tiller pilot plant are less than 1 h, 3.5–6 h and 3.5–4 h for step changes in flue gas flow rate, solvent flow rate and reboiler duty, respectively.

[1]  Meihong Wang,et al.  Investigating the dynamic response of CO2 chemical absorption process in enhanced- O2 coal power plant with post-combustion CO2 capture , 2011 .

[2]  Ana-Maria Cormos,et al.  Dynamic modeling and validation of absorber and desorber columns for post-combustion CO2 capture , 2011, Comput. Chem. Eng..

[3]  Gary T. Rochelle,et al.  Optimum design and control of amine scrubbing in response to electricity and CO2 prices , 2011 .

[4]  Bernt Lie,et al.  Amine based CO2 capture plant: Dynamic modeling and simulations , 2013 .

[5]  Eric Croiset,et al.  Dynamic simulation of MEA absorption process for CO2 capture from power plants , 2012 .

[6]  Jon Gibbins,et al.  Initial evaluation of the impact of post-combustion capture of carbon dioxide on supercritical pulverised coal power plant part load performance , 2007 .

[8]  H. M. Kvamsdal,et al.  Dynamic modeling and simulation of a CO2 absorber column for post-combustion CO2 capture , 2009 .

[9]  H. Yeung,et al.  Dynamic modelling of CO 2 absorption for post combustion capture in coal-fired power plants 1 , 2008 .

[10]  Nilay Shah,et al.  Flexible operation of solvent regeneration systems for CO2 capture processes using advanced control techniques: Towards operational cost minimisation , 2012 .

[11]  H. Yeung,et al.  Dynamic modelling and analysis of post-combustion CO2 chemical absorption process for coal-fired power plants , 2010 .

[12]  Chechet Biliyok,et al.  Dynamic modelling, validation and analysis of post-combustion chemical absorption CO2 capture plant , 2012 .

[13]  James R. Fair,et al.  Distillation Columns Containing Structured Packings: A Comprehensive Model for Their Performance. 2. Mass-Transfer Model , 1996 .

[14]  H. Yeung,et al.  Dynamic Modelling and Analysis of Post-Combustion CO 2 Chemical Absorption Process for Coal-fired Power Plants , 2011 .

[15]  Nina Enaasen Flø,et al.  Post-combustion absorption-based CO2 capture: modeling, validation and analysis of process dynamics , 2015 .

[16]  Jozsef Gaspar,et al.  Dynamic modeling and absorption capacity assessment of CO2 capture process , 2012 .

[17]  B. Lie,et al.  A simulation study on the abatement of CO2 emissions by de‐absorption with monoethanolamine , 2010, Environmental technology.

[18]  Gary T. Rochelle,et al.  Dynamic Modeling to Minimize Energy Use for CO2 Capture in Power Plants by Aqueous Monoethanolamine , 2009 .

[19]  Meihong Wang,et al.  Dynamic modelling of CO2 absorption for post combustion capture in coal-fired power plants , 2009 .

[20]  Bernt Lie,et al.  Dynamic modelling of the absorber of a post-combustion CO2 capture plant: Modelling and simulations , 2013, Comput. Chem. Eng..

[21]  James R. Fair,et al.  Distillation columns containing structured packings: a comprehensive model for their performance. 1. Hydraulic models , 1993 .

[22]  Matthew Leach,et al.  Flexible Operation of Coal Fired Power Plants with Postcombustion Capture of Carbon Dioxide , 2009 .

[23]  Richard Faber,et al.  Open-loop step responses for the MEA post-combustion capture process: Experimental results from the Esbjerg pilot plant , 2011 .

[24]  Magne Hillestad,et al.  Dynamic model validation of the post-combustion CO2 absorption process , 2015 .