Preparation of Waste Coffee Ground-Based Microporous Carbons for CO2 Capture

As the amount of CO₂ in the atmosphere increases, global warming deepens and climate change problems are occurring. Therefore, CO₂ capture and storage (CCS) technology is considered one of the ways to reduce the amount of emitted CO₂. In particular, more than 80% of the total cost of CCS technology is accounted by the capturing stage, therefore efficient CO₂ capturing technology is essential. Absorption, adsorption, and membrane separation are mainly used in post-combustion capture technology. Among them, the adsorption has advantages of low energy consumption and easy regeneration. However, its performance is lower than that of the conventional absorption technology. Thus, it is required to develop efficient adsorbents. Among various materials used as an adsorbent, activated carbon is advantageous in that it is easy to synthesize, cost competitive, and easily controlled in pore size. In this study, waste coffee grounds were used as a carbon precursor and porous carbon materials were synthesized by using K₂CO₃ as an activating agent. Based on the discarded coffee grounds in daily life, high value-added microporous carbon was produced by the simple synthesis method. The changes of surface area and CO₂ adsorption performance were analyzed with the activation temperature and time and the correlations between the variables were investigated.