Optimization of the chemical activation conditions to produce bio-based carbons for energy

FLORENCIA JEREZ; PAMELA B. RAMOS; FEDERICO PONCE; GERARDO G. ACOSTA; BAVIO, MARCELA A.

Buenos Aires

Congreso; WCCE11 - 11th WORLD CONGRESS OF CHEMICAL ENGINEERING; 2023

World chemical engineering council - Asociación Argentina de Ingenieros Químicos

The continuous growth of the global population increases consumption; thus, a large amount of waste is generated. Developing waste valorization technologies is the key to reducing the environmental impact that these provoke. The production of chemically activated carbon using lignocellulosic waste for energy storage is widely studied, but there is no information on its production using yerba mate waste. This waste is abundant in countries like Argentina, Uruguay, and Paraguay due to its annual consumption of ca 5.88 Kg per capita. This work aims to optimize the activation conditions for producing chemically activated carbon derived from yerba mate waste to be used as active material in supercapacitors. A central composite design was used to study the influence of the carbonization temperature, the impregnation ratio (activating agent, KOH), and the activation temperature. The specific capacitance (Fg-1) was selected as the response variable. The response surface methodology results demonstrated that carbonization and activation temperature significantly influenced specific capacitance. The conditions for maximum specific capacitance were as follows carbonization temperature of 400 °C, an impregnation ratio of 6.69/1, and an activation temperature of 768 °C. A specific capacitance of 242.6 Fg-1 was obtained in these conditions and validated the model. Also, a maximum specific capacitance, energy, and power of 344.9 Fg-1, 95.8 Whkg-1, and 49500 Wkg-1, respectively, were obtained for this material. These electrochemical properties are appropriate as active materials for supercapacitors. Thus, valorizing the yerba mate waste for a technological application was possible.