Synthesis and characterization of activated carbon from biomass date seeds for carbon dioxide adsorption

In this study, activated carbons were synthesized from seeds of local date fruits in the United Arab Emirates (UAE) and investigated for carbon dioxide (CO2) adsorption. Activated carbon (AC) synthesis was completed by furnace activation in the temperature range (600, 700, 800, 900 °C) after infusion with chemical compounds. Two reagents (Potassium Hydroxide- KOH and Sulfuric acid- H2SO4) were mixed with the date seed samples in varying impregnation ratios (KOH- 3:1, 4:1, 5:1 and H2SO4- 0.5:1, 1:1, 2:1) and directly heated to activation wherein the removal of volatile matter content leads to formation of AC porous structure. The AC yield was found to be inversely proportional to the activating temperature and impregnating ratio. Characterization tests carried out include elemental analysis, nitrogen sorption isotherms to assess surface area and micropore volumes, and Fourier transform infrared spectra to identify structural changes in surface functional groups. Adsorption tests were conducted via a micro- reaction calorimeter using pure CO2 stream at atmospheric pressures and temperatures (20, 30, 40 °C). The sulfuric acid activated carbons showed better capture capability in the range 40-80 mgCO2/gAC while KOH- samples had low CO2 uptakes (< 20 mg/g). The research study presents findings on chemical activation procedures for date seeds synthesized adsorbents for carbon dioxide capture and its potential applications for solid sorbent systems.