INTRODUCTION

Global warming which was attributed to the increase in anthropogenic emissions of carbon dioxide to the environment has led to an increase in the undesirable events, such as rise in sea level, species extinction and others. For instance, carbon dioxide (CO2), which is one of the potent greenhouse gases has shown a steady increase in concentration over the years, with the concentration of CO2 have surpassed 400 ppm since 2013 (Current CO2 concentration in the atmosphere (in the year 2022) is reported to be 416 ppm). In general, research efforts on CO¬2 capture have been focused on capturing CO2 at point source, namely CO2 that is released from coal or fossil-fuel based power plants (i.e., post-combustion CO2 capture, with CO2 concentration in the flue gas are typically ranging from 12 - 20 vol%). However, this carbon capture technology has often failed and may not be fully applicable towards effective removal CO2 that are present in the atmosphere, due to the substantial difference in the feed composition (CO2 concentration of c.a. 400 ppm). In comparison to the available unit operations that are available in the market (e.g., cryogenic distillation, amine scrubbing (absorption) and membrane), utilization of porous materials (adsorbent) is expected to be the most practically feasible option to capture CO2 directly from ambient air (direct air capture, DAC).