Comparative analyses of carbon dioxide capture from power plant flue gas surrogate by micro and mesoporous adsorbents

Abstract

Pressure swing adsorption (PSA) performances using 5 different types of adsorbents were compared to observe their usefulness in achieving the balance between purity and recovery of the captured carbon dioxide (CO2). Three of the adsorbents were mesoporous (pore size of greater than 2 nm), whereas the other two adsorbents were microporous (pore size of smaller or equal to 2 nm) in nature. Among the 5 adsorbents being tested, microporous palm kernel shell (PKS) reinforced with cerium and silica species was found to yield the maximum CO2 purity of 85.42% from the initial 15.00% CO2 purity in the feed (˜5 fold increase in the purity) with CO2 recovery of 54.62% in the first cycle of PSA operation. The PKS was found to perform better CO2 capture than its more expensive inorganic micro-porous ZIF-8 counterpart and the other mesoporous organic adsorbents, possibly due to the high affinity of Ce species that was present in the sample. The energy saving gained from PSA operated with the equalization mode using PKS reached 75.15% over 5 cycles of operation with further increase in CO2 recovery to 75.20% (37.70% increase) in the fifth cycle.