Evaluating the experimental CO2 stripping performance of a new generation multicapillary Taylor flow reactor

Abstract

Among all physicochemical technologies commercially available to upgrade biogas to biomethane, chemical scrubbing with carbonated solutions stand as an easy-to-scale technology. However, the regeneration of the solvent via air-assisted CO2 stripping is highly energy-intensive, representing >80 % of the total process costs. This study proposes the use of innovative Taylor flow reactors to enhance the liquid-gas mass transfer of CO2 and therefore lower the cost of regeneration of carbonated solutions. In this study, a 200-glass capillary Taylor flow reactor supporting unprecedented mass transfer coefficients (kLa) was tested for the first time for CO2 stripping from carbonated solutions. The Taylor flow reactor achieved kLa coefficients higher than 100 h-1 at an inorganic concentration (IC) of 1000 mgC L-1, and kLa > 400 h-1 at an optimal gas superficial velocity of 0.30 m s-1. Moreover, increasing IC concentrations to 2000 and 3000 mgC L-1 resulted in a kLa increase of 250 % and 65 %, respectively, whilst no significant increase was recorded at an initial IC concentration of 4000 mgC L-1. Indeed, multicapillary Taylor flow reactors demonstrated a superior and competitive performance during CO2 stripping from carbonated solutions, representing a promising technology for solvent regeneration during biogas upgrading at industrial scale.