The effects of CO2 activation, on porosity and surface functional groups of cocoa (Theobroma cacao) – Shell based activated carbon

A series of activated carbon from cocoa shell (CSAC) was prepared from cocoa shell pellet (CS) by carbonization and followed by physical activation using CO2 as the activation agent. Carbonization was done in a flow of N2 using a fixed-bed reactor at 400, 500, 600, 700, 800 and 900 °C with soaking time at the carbonization temperature for an hour. The selected char indicated completion of the aromatization process which suggests no structural changes beyond this temperature. Char monolith, carbonized at 800 °C were activated at 850 °C using a fixed bed reactor for different burn-offs. The drilling of the pores possibly occurred at burn-off below 60% which indicated by huge increase of absolute pore volume against the burn-off. The surface area at 48.5% burn-off was estimated at 366.26 m2 g−1. High burn-off product tends to develop larger micropore and moderate BET surface area. The largest surface area of CSAC was recorded at 558.25 m2 g−1. During activation, the aromatization of CSAC increased but the aliphacity decreased accordingly.