Carbon Dioxide Adsorption over Activated Carbons Produced from Molasses Using H2SO4, H3PO4, HCl, NaOH, and KOH as Activating Agents

Cost-effective activated carbons for CO2 adsorption were developed from molasses using H2SO4, H3PO4, HCl, NaOH, and KOH as activating agents. At the temperature of 0 degrees C and a pressure of 1 bar, CO2 adsorption equal to 5.18 mmol/g was achieved over activated carbon obtained by KOH activation. The excellent CO2 adsorption of M-KOH can be attributed to its high microporosity. However, activated carbon prepared using HCl showed quite high CO2 adsorption while having very low microporosity. The absence of acid species on the surface promotes CO2 adsorption over M-HCl. The pore size ranges that are important for CO2 adsorption at different temperatures were estimated. The higher the adsorption temperature, the more crucial smaller pores were. For 1 bar pressure and temperatures of 0, 10, 20, and 30 degrees C, the most important were pores equal and below: 0.733, 0.733, 0.679, and 0.536 nm, respectively.

Automated summary

Cost-effective activated carbons for CO2 adsorption were developed using different activating agents. The activated carbon obtained by KOH activation showed excellent CO2 adsorption due to its high microporosity. On the other hand, the activated carbon prepared using HCl showed high CO2 adsorption while having low microporosity. The pore size ranges important for CO2 adsorption were estimated at different temperatures, with smaller pores becoming more crucial at higher temperatures.