Development of a CO2 Capture Process Based on Ammonia Solvent and a Dedicated Composite Hollow Fibre Membrane Contactor

AbstractCO2 capture is recognized as necessary to achieve significant greenhouse gas emission reduction before 2050. Regarding these technologies, the main issue is the high cost of avoided CO2 related to capture (≈40 €/t). In conventional amine-based CO2 capture process, the four main key parameters driving the cost of avoided CO2 are the regeneration duty, the compression works, the compressor cost and the solvent make-up cost. On the one hand, the use of hollow fibre membrane contactor (HFMC) for CO2 capture is foreseen to be an efficient technology for absorber intensification; but regarding the impact of the absorber cost on the cost of avoided CO2, the use of HFMC for process intensification does not seem relevant. On the other hand, ammonia as solvent for CO2 capture is a cheap solvent with no degradation problem. Moreover, it allows a high pressure regeneration reducing the compression works.The key idea of this work is to find a membrane with high CO2/NH3 selectivity and high permeability in order to use aqueous ammonia as a solvent in a HFMC in order to reduce significantly the ammonia slip in flue gases while maintaining high absorption rate. The work has been divided in three main steps: the screening of available material for the membrane, the laboratory test of the membrane and the modelling of the system for process assessment. For this absorption device a total equivalent work of 240 kWh/tCO2 has been calculated for CO2 capture on a coal-fired power plant