Carbon dioxide activation of the plane tree seeds derived bio-char: Kinetic properties and application

Abstract

Goal of this work is to establish technical feasibility and fundamentals of producing activated carbon from plane tree seeds biomass for porous materials derivation. Bio-chars produced via carbonization from plane tree seeds precursor were activated in CO2 at 750 and 850?C, during various residence times. Their surface area and porosity were characterized by N2 adsorption at 77 K. Surface areas of activated carbons can be correlated with kinetics mechanism and activation energy magnitudes of oxidation reaction by CO2, which are closely related to applied activation temperature. Result showed that high temperature activated carbon had higher gas adsorption as compared to activated carbon obtained from lower temperature during two-hour residence time. Breakthrough behavior was detected at 850?C where surface reactions dominate, and it is characterized by autocatalytic kinetic model under designed conditions. Both, temperature and CO2 concentration in vicinity of solid surface effect on breakthrough time of adsorbent. Derived bio-chars are converted into high quality activated carbons, with surface area of 776.55 m2/g, where micro-pores with pore diameters less than 2 nm prevail. Produced activated carbons have properties comparable with commercially available activated carbons, which can be successfully used for removal of harmful gaseous pollutants toward air purification.