Improving the Surface Areas and Pore Volumes of Bio-char Produced from Pyrolysis of Cotton Gin Trash via Steam Activation Process

— Cotton gin trash (CGT) was pyrolyzed in a batch reactor and the char produced was activated with superheated steam to generate an activated carbon product. Activated carbon is a valuable adsorptive material for water and wastewater treatment systems. The main objective of the study is to compare the activated carbon produced from CGT with commercial grade activated carbon. The effect of pyrolysis temperature (600oC, 700oC and 800oC), activation temperature (250oC-600oC) and exposure time (30, 45 and 60 minutes) on the properties of activated carbon were made. Result showed an increase in the iodine number from 200 to 427 was observed at 7000C and 45 minutes exposure time. These data indicate that CGT may be a potential feedstock for making commercial grade powdered activated carbons that may be used for wastewater treatments. In this paper, we introduce the term biomass iodine number (BIN). Some biomass-based activated carbon have similar performance with commercial grade activated carbon even if the former has high inorganic components hence, lowering its iodine number. The use of BIN would make it easier to compare commercial grade activated carbon (with very low ash content) with biomass-based activated carbon (high in ash) when it comes to determining the loading rates for pollutant clean up. The optimized activated carbon produced from this study has a BIN of 642 and comparable with lower grade commercial activated carbon with iodine number of 600. If the loading rate of this biomass-based activated carbon is increased by 40%, its adsorptive properties will be equal to that of a commercial grade activated carbon with iodine number of 1000. Hence, this new terminology for biomass-based activated carbon is important for trading biomass-based activated carbon with relatively high ash contents but of equal adsorptive properties with commercial-grade materials.