Synthesis and application of biochar from agricultural by-products. Effect of pyrolysis temperature on the acid-base properties of biochar

Abstract

Biochar was synthesized from banana peels using the pyrolysis method in a nitrogen gas environment. The pyrolysis temperature ranged from 100°C to 500°C with a heating rate of 5°C per minute and a pyrolysis time of 1.5 hours. The influence of the pyrolysis temperature on the acid-base properties of the biochar surface was evaluated through characteristic SEM and BET measurements. Boehm titration showed a gradual decrease in the total acid functional groups and an increase in the total base functional groups with the increasing pyrolysis temperature. Methylene Blue (MB) was used as a model substance to investigate the adsorption properties of the synthesized biochar. The Langmuir and Freundlich models were employed to describe the adsorption equilibrium. The kinetics of MB adsorption followed a pseudo-second-order kinetic equation. The adsorption capacity of MB by biological charcoal was influenced by the acid-base properties of the material, indicating the impact of the pyrolysis temperature.