Theoretical approach to CO2 absorption in microreactors and reactor volume prediction

Abstract

Parametric analysis is presented for CO2 absorption process using the Danckwerts mass transfer model, which enables an efficient target-oriented design of microreactors. Instead of trial-error evaluation over given reactors, this work provides a quantitative study on the effects of various parameters (i.e., flow rate, reaction rate, system pressure) on the reactor volume. It is found that increasing system pressure can significantly reduce the reactor volume, offsetting the disadvantage of microreactors with limited volume. This work also evaluates the end effect of lab-scale tests that results from the absorption in the connecting tube and the gas-liquid separator. With the theoretical approach, the end effect is shown to increase with the increase of the throughput, which is in accordance with experimental results. The amount of CO2 absorbed in the end volume can be as large as 23 %∼47 % of the total CO2 absorbed, indicating a rather serious end effect.