Modeling of rapid temperature swing adsorption using hollow fiber sorbents

• Published in: Chemical engineering science 2014-07, Vol.113, p.62-76
• Main Authors: Rezaei, Fateme, Subramanian, Swernath, Kalyanaraman, Jayashree, Lively, Ryan P., Kawajiri, Yoshiaki, Realff, Matthew J.
• Format: Article
• Language: English
• Subjects: Adsorption; Carbon capture and storage; Carbon dioxide; CO2 capture; Coal-fired power plant; Contactors; Cyclic adsorption process; Fibers; Heating; Hollow fiber sorbents; Mathematical models; Rapid temperature swing adsorption; Sorbents
• ISSN: 0009-2509; 1873-4405
• DOI: 10.1016/j.ces.2014.04.002

The use of novel polymeric hollow fiber contactors loaded with CO2 sorbents has been recently demonstrated experimentally as a new and scalable process configuration for post-combustion CO2 capture. The hollow fiber contactor allows coupling of efficient heat transfer and gas contacting, potentially yielding lower parasitic loads on host power plants compared to traditional contacting strategies using solid sorbents. In this study, a two dimensional mathematical model of a rapid temperature swing adsorption (RTSA) process is developed for the first time to predict polymer-supported amine hollow fiber sorbent performance during post-combustion CO2 capture from flue gas. In particular, this work is focused on developing a single fiber model to simulate a four-step RTSA system accounting for adsorption, heating/desorption, heating/sweeping and cooling steps. The model is validated with experimental breakthrough data obtained from our RTSA system. The sensitivity of the model to parameter values such as gas and water velocity and initial temperatures are evaluated accordingly by considering the effect of these parameters on CO2 concentration and temperature profiles. Furthermore, the CO2 adsorption isotherms obtained experimentally were fitted with the Toth model. In addition, our model was validated against experimental breakthrough profiles. A good agreement was found between experimental and numerical data indicating that our proposed model can describe experimental observation very well. The numerical results obtained from RTSA cycle modeling indicate that under operating conditions considered here, it is possible to achieve high purity and recovery within a cycle time of shorter than 3min. It was also found that there is a trade-off in cycle time, shorter for lower capital cost and longer to enable heat recovery for lower utility costs. •The modeling of novel polymeric hollow fiber contactors loaded with CO2 adsorbents are reported.•A four-step hollow fiber RTSA system is simulated by a single fiber model.•Heat and mass balances are developed in different phases of the fiber.•The sensitivity of the model to process parameters is evaluated.•Hollow fiber RTSA system provides a novel cost-effective and scalable pathway for CO2 capture.