AUTHOR=Schellevis Michel , Jacobs Tim , Brilman Wim 

TITLE=CO2 Capture From Air in a Radial Flow Contactor: Batch or Continuous Operation?

JOURNAL=Frontiers in Chemical Engineering

VOLUME=2

YEAR=2020

URL=https://www.frontiersin.org/journals/chemical-engineering/articles/10.3389/fceng.2020.596555

DOI=10.3389/fceng.2020.596555

ISSN=2673-2718

ABSTRACT=<p>The capture of CO<sub>2</sub> from the atmosphere via Direct Air Capture using solid supported-amine sorbents is an important option to reduce the atmospheric concentration of CO<sub>2</sub>. It addresses CO<sub>2</sub> emissions from dispersed sources and delivers a location independent, sustainable carbon source. This study evaluates the possibility for a continuous adsorption process for direct air capture in a radial flow contactor, using both batch and continuous mode of operation. Gas and solid flow were varied to determine hydrodynamic feasible operating conditions. The operation modes are compared by their capture efficiencies in the optimal adsorption time range of 0.5 <inline-formula id="inf1"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>t</mml:mi><mml:mrow><mml:mtext>sto</mml:mtext></mml:mrow><mml:mi>B</mml:mi></mml:msubsup></mml:mrow></mml:math></inline-formula> and 1.5 <inline-formula id="inf2"><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow><mml:msubsup><mml:mi>t</mml:mi><mml:mrow><mml:mtext>sto</mml:mtext></mml:mrow><mml:mi>B</mml:mi></mml:msubsup></mml:mrow></mml:math></inline-formula>. A 15–25% lower capture efficiency is found for a continuous process compared to a batch process in the relevant range for direct air capture. This decline in gas-solid contact efficiency is more pronounced at longer adsorption time and higher superficial gas velocity. Overall, a batch process is preferred over a continuous process in the majority of operating conditions.</p>