IMPACT OF ACTIVATION ON CO-PYROLYZED MANGO (Magnifera indica) AND SOURSOP (Annona muricata) SEEDS BIOCHAR

Abstract

Co-pyrolysis of Annona muricata and Magnifera indica resulted in the production of biochar at temperatures of 350, 400, 500oC, heating rate of 5 oCmin-1, and residence times (tr) of 45 min and 2 h. Co-pyrolyzed biochar was then physically and chemically activated at 850°C for 75 min using CO2 and KOH, respectively. The Brunauer-Emmett-Teller (BET) method was used to calculate the specific surface area of the biochar using nitrogen adsorption at 77 K (as,BET). The functional groups present were determined using FTIR spectroscopy. The BET values for the physically and chemically activated biochar were respectively 18.30 m2g-1 and 574.63 m2g-1 for high tr of 2 h and 228.20 m2g-1 and 810.55 m2g-1 for low tr of 45 min. The porous biochar had peaks corresponding to N-H/O-H, C=O, C-O, and C=C bonds. The intensity of the biochar peak was shown to be negatively correlated with the pyrolysis temperature. All samples had high as,BET at low tr. When compared to chemical activation, physical activation was found to significantly enhance the biochar's surface area, increasing its potential for industrial usage.