Modeling of slurry staged bubble column for biomimetic CO2 capture. (April 2016)

• Record Type: Journal Article
• Authors: Russo, Maria Elena; Bareschino, Piero; Olivieri, Giuseppe; Chirone, Riccardo; Salatino, Piero; Marzocchella, Antonio
• Is Part Of: International journal of greenhouse gas control. Volume 47(2016:Apr.)
• Page Start: 200
• Page End: 209
• Publication Date: 2016-04
• Subjects: CO2 capture -- Carbonic anhydrase -- Immobilized enzyme -- Slurry -- Staged bubble column; Greenhouse gases -- Environmental aspects -- Periodicals; Air -- Purification -- Technological innovations -- Periodicals; Gaz à effet de serre -- Périodiques; Gaz à effet de serre -- Réduction -- Périodiques; Air -- Purification -- Technological innovations; Greenhouse gases -- Environmental aspects; Periodicals; 363.73874605
• DOI: 10.1016/j.ijggc.2016.01.045
• Languages: English
• ISSNs: 1750-5836

Abstract

Graphical abstract: Highlights: The model describes CO2 absorption in slurry of K2 CO3 solutions containing immobilized CA. Other than SBC, the model can simulate different absorber configurations. Immobilized CA slurry enhanced CO2 absorption rate of K2 CO3 solution in the SBC. Absorption enhancement is very sensitive to enzyme kinetics. The model was solved using Comsol Multiphysics® software package. Abstract: The biomimetic CCS strategy is based on the enhancement of CO2 absorption rate into aqueous solutions by the enzyme carbonic anhydrase (CA). Immobilized CA on fine dispersed solids promotes the heterogeneous biocatalysis close to the gas–liquid interface and the enhancement of CO2 absorption rate. In this work a theoretical model of a slurry absorption unit for the biomimetic CO2 capture in K2 CO3 solutions was developed and solved using the commercial software package Comsol Multiphysics®. The staged bubble column (SBC) configuration was selected to capture CO2 in aqueous slurry containing immobilized CA under counter-current gas–liquid flow. The theoretical framework included: the 'tanks-in-series' model to describe the unit; the two films theory to describe the absorption rate at the gas–liquid interface; the pseudo-homogeneous approach and a reversible Michaelis and Menten kinetics to model CO2 conversion by the slurry biocatalyst. The simulations provided the CO2 capture rate and the CO2 concentration profiles in the liquid boundary layer. Simulation results showed that the CO2 capture rate poorly increased when dissolved CA was used within the solubility limit (≈100 mg/L). Remarkably, about three fold enhancement of the CO2 absorption rate with respect to pure alkaline solvent when absorption in the presence of CA immobilized on fine particles was simulated.