(186e) Vacuum Membrane Distillation of CO2-Rich Alkanolamines

To mitigate climate change around the world, lots of technologies are on the competition. Chemisorption using alkanolamine is considered as the most competent technology especially when applied for the flue gas. However, the capture of carbon dioxide in a packed column has a very weak point in its energy intensiveness. Also, gas and liquid flow velocities are strictly restricted due to operating problems such as flooding, channeling, foaming and entrainment. [Kumar, 2002] Membrane gas/liquid contactor is known to be relevantly free from these problems, and now researched rapidly.

 Membrane contactor can be used as absorber and stripper. Membrane distillation for regenerating amine solvent is energy-saving and also good for process intensification due to high surface to volume ratio. Especially, sweeping gas membrane distillation (SGMD) and vacuum membrane distillation (VMD) are the technologies that are frequently used in the experimental level. SGMD papers used nitrogen or argon as the sweeping gas which is hard to separate from carbon dioxide. [Khaisri, 2011] [Naim, 2012] So, vacuum membrane distillation using low quality steam as a sweeping gas can be applied instead of packed column carbon capture amine scrubbing.

 Still, this VMD system is not well-simulated mathematically. In this presentation, some experimental results of vacuum membrane distillation data from [Fang, 2012] [Wang, 2013] [Yan, 2012] are validated with over-all mass transfer model using local composition model. And membrane contactor modularity for the scale-up is checked toward real application. Also some operating problems like membrane-wetting are considered.

This research was supported by the LNG Plant R&D Center funded by the Ministry of Land, Transportation and Maritime Affairs (MLTM) of the Korean government

Reference List

- Fang M, et al, CO2 desorption from rich alkanolamine solution by using membrane vacuum regeneration technology, International Journal of Greenhouse Gas Control 9(2012) 507-521

- Khaisri S, deMontigny D et al, CO2 stripping from monoethanolamine using a membrane contactor. Journal of Membrane Science 376(2011) 110–118

- Kumar PS. Development and Design of Membrane Gas absorption Processes. PhD Thesis, University of Twente, Enschede, The Netherlands.

- Naim R et al, Preparation of microporous PVDF hollow fiber membrane contactors for CO2 stripping from diethanolamine solution, Journal of Membrane Science 392– 393(2012) 29– 37

- Wang Z et al, Amine-based absorbents selection for CO2 membrane vacuum regeneration technology by combined absorption-desorption analysis, Chemical Engineering Science 93(2013) 238-249

- Yan S, et al, Regeneration performance of CO2-rich solvents by using membrane vacuum regeneration technology: Relationship between absorbent structure and regeneration efficiency, Applied Energy 98 (2012) 357-367