CO₂ Adsorption: Experimental Investigation and CFD Reactor Model Validation

Abstract

The National Energy Technology Laboratory is investigating a new process for CO 2 capture from large sources such as utility power generation facilities as an alternative to liquid amine based adsorption processes. Many of these advanced dry processes are based upon sorbents composed of supported polyamines. In this analysis, experiments have been conducted in a laboratory-scale fluidized bed reactor and compared to CFD reactor predictions using kinetics obtained from TGA tests. Batch experiments were conducted by flowing a mixture of CO 2 , H 2 O, and N 2 (simulated flue gas) through a fluidized bed of sorbent material. The exit gas composition time series data is compared to CFD simulations using a 3-dimensional nonisothermal reacting multiphase flow model. The effects of the gas flow rate, distributor design, and particle size are explored through the CFD simulations. It is shown that the time duration for CO 2 adsorption decreased for an increase in the gas flow. Fluid bed hydrodynamics indicated that there were regions in the reactor where the inert FCC particles segregated and defluidized; without adversely affecting the capacity of the sorbent to adsorb CO 2 . The details of the experimental facility and the model as well as the comparative analysis between the data and the simulation results are discussed.

Cyclic Tests in Batch Mode of CO2 Adsorption and Regeneration with Sorbent Consisting of Immobilized Amine on a Mesoporous Silica

“…The central core comprised about 15% of the mass inventory; therefore, a defluidized central core was considered the most likely cause leading to this low pressure differential. In a computational fluid dynamic study of the hydrodynamics with this distributor configuration, but no internal coils, some stagnation was reported in the central core region; however, the Δ P was 28% lower than the expected weight of the bed. A calculation of the volume between the coils suggests that this would be sufficient to explain reduced pressure differential, representing 14% of the volume.…”

Polyethylenimine Applications in Carbon Dioxide Capture and Separation: From Theoretical Study to Experimental Work

“…Breault et al. compared results of the 3D non‐isothermal multiphase CFD simulation by using kinetics obtained from thermogravimetric analysis (TGA) with batch experiments conducted by flowing a mixture of CO 2 and N 2 gas and vapor through a fluidized bed, and found that the time duration of CO 2 capture decreased with increasing gas flow . Recently, Breault et al.…”