Modeling CO₂ Mass Transfer in Amine Mixtures: PZ-AMP and PZ-MDEA

Abstract

The most common method of carbon dioxide (CO(2)) capture is the absorption of CO(2) into a falling thin film of an aqueous amine solution. Modeling of mass transfer during CO(2) absorption is an important way to gain insight and understanding about the underlying processes that are occurring. In this work a new software tool has been used to model CO(2) absorption into aqueous piperazine (PZ) and binary mixtures of PZ with 2-amino-2-methyl-1-propanol (AMP) or methyldiethanolamine (MDEA). The tool solves partial differential and simultaneous equations describing diffusion and chemical reaction automatically derived from reactions written using chemical notation. It has been demonstrated that by using reactions that are chemically plausible the mass transfer in binary mixtures can be fully described by combining the chemical reactions and their associated parameters determined for single amines. The observed enhanced mass transfer in binary mixtures can be explained through chemical interactions occurring in the mixture without need to resort to using additional reactions or unusual transport phenomena such as the "shuttle mechanism".

Performance of MEA and amine-blends in the CSIRO PCC pilot plant at Loy Yang Power in Australia

“…The steam is needed to create a driving force for CO 2 stripping in the stripper column. Using a model developed in our group [18], we can also estimate an equilibrium CO 2 partial pressure of MEA, AMP and Blended Amine 1 as described in Fig. 8.…”

Efficient capture of carbon dioxide with novel mass‐transfer intensification device using ionic liquids

“…Lots of alternative solvents have been explored to verify the feasibility for commercial deployment. [19][20][21] Recently, ionic liquids (ILs) provide a promising new option for CO 2 capture. [22][23][24][25][26][27][28] Much of this interest stems from several interesting properties of ILs: high thermal stability, extremely low volatility, good solubility of CO 2 , and the ability to manipulate solvent properties through ion selection.…”

Carbonate solutions for carbon capture: A summary

“…They should also provide some benchmarks to compare with whetted-wall experiments on lean solutions. The next logical step in mass-transfer modeling is probably a reaction-coupled finite element model, such as created by Puxty and Rowland (2011). Such a model can take into account reverse reactions and competing reaction pathways, which will allow accurate handling of absorption in rich solutions and desorption in the stripper, if desired (the kinetics of stripping are given much less attention in the literature, presumably because reactions at the higher stripping temperature are fast enough to be unimportant).…”

“…The "specific ion interaction theory" (SIT) model is sometimes used (e.g. Puxty and Rowland, 2011), but the Pitzer model is preferred, and is challenging for its complexity and many adjustable parameters which must be calibrated against empirical data. Using activity coefficients, however, is the more rigorous and modern approach.…”