Post-combustion CO2 capture using super-hydrophobic, polyether ether ketone, hollow fiber membrane contactors

The feasibility of utilizing a super-hydrophobic polyether ether ketone (PEEK) hollow fiber membrane contactor in combination with chemical solvents to separate and capture CO2 from simulated flue gases was investigated. Greater than 90% CO2 capture with greater than 95% CO2 purity has been achieved in one stage with both activated methyldiethanolamine (aMDEA) and activated K2CO3 solvents. The measured volumetric mass transfer coefficient was as high as 1.7 s(-1), which is more than 20 times greater than the mass transfer coefficient of a packed column. Preliminary tests indicated that the CO2 capture performance was not affected by flue gas contaminants, including O-2, NO2, and SO2, with aMDEA solvent. The PEEK membrane module showed good mechanical properties and stable permeation properties at process design conditions for duration of the test (120 h). The process economics were evaluated assuming direct substitution of the conventional absorber by the membrane contactor, while using a conventional packed column in the regeneration step. Relative to the cost estimation with no CO2 capture, the evaluation indicates a 56% increase in the levelized cost of electricity (LCOE) for the PEEK membrane contactor technology, which is 29% lower than DOE's benchmark amine absorption technology (85% increase in LCOE). (C) 2012 Elsevier B.V. All rights reserved.