Thermochemical activation of raw chickpea (Cicer arietinum) stalk biomass for enhanced valorization

Abstract

A study was undertaken to enhance the value of raw chickpea stalks by converting them into activated carbon. The production process involved chemical activation using potassium hydroxide (KOH) at 800 °C in a nitrogen (N2) gas atmosphere. Various properties of both the raw chickpea stalk and the resulting activated carbon were examined and compared, including BET surface area, scanning electron microscopy (SEM) images, proximate and elemental analyses, absorption characteristics, and calorific value. Results indicated that the activated carbon had a specific surface area of 1239 m2/g, a total pore volume of 0.6 cm3/g, a methylene blue value of 320 mg/g, and an iodine value of 122 mg/g. SEM analysis revealed that the synthesized activated carbon exhibited high porosity with interconnected pores resembling a honeycomb structure. The study concluded that thermochemical activation successfully valorized the raw chickpea stalk, leading to improved properties of the activated carbon. Potential applications for this activated carbon include dye removal, water purification, and gas storage.