Parametric behavior of a riser CO_2 adsorption process CFD simulation of solid-sorbent CO_2 absorption in a riser reactor

摘要

The National Energy Technology Laboratory as well as other institutions are in the process of conceptualizing a variety of new technologies as an alternatives to liquid -amine based absorption processes for post-combustion CO_2 capture from large sources such as Utility power generation facilities. At low temperature, most, but not all of these advanced dry processes are based upon sorbents composed of supported polyamines. This particular investigation simulates the predicted performance of one of these amine sorbents in a reactor. As conceptualized, the process would adsorb CO_2 from flue gas in a riser reactor, separate the carbonated particles from the de-carbonated flue gas and then regenerate the sorbent, creating a concentrated stream of pure CO_2 for sequestration. In this work, the adsorber performance is simulated using multiphase computational fluid dynamics complete with chemistry and thermal effects using a 3-dimensional model for the riser. An eight point test matrix was used to explore the behavior and performance of the riser adsorber with respect to solids circulation rate, gas flow rate and heat removal. It is shown that CO_2 adsorption increases with an increase in the solids flow, decreases for an increase in the gas flow and decrease with an increase in the reactor temperature. The specifics for the model and the simulation results will be discussed.