Performance of activated carbon derived from tea twigs for carbon dioxide adsorption

Activated carbon from agro-industrial waste, namely tea twigs derived from the processing of Camellia Sinensis branches, using a potassium hydroxide activator for CO 2 adsorption has been conducted in this study. Various carbonization temperatures (400 0 C and 500 0 C) and heating times of 1 h and 3 h were used in this study. The concentration of potassium hydroxide (40 % and 60 %) and the ratios of activator solutions to carbon precursor made from pyrolysis of tea twigs (2:1 and 4:1) were varied for the chemical activation process. The effectiveness results of the obtained activated carbon were characterized through using Brunauer-Emmett-Teller analyzer and Temperature Programme Desorption-CO 2 to determine the surface area and capacity maximum of CO 2 adsorption. The optimum condition for the synthesis of activated carbon that produces high surface area was obtained at sample CCS 400/1 A 2 B 1 where biochar carbonized at temperature of 400 °C kept for 1 h with a ratio of activator solution and precursor 4:1 using KOH concentration of 40 %. The highest surface area was obtained 1403 m 2 g −1 with pore volume 0.9 m 2 g −1 and pore size 1.11 nm and proved the presence of microporous areas in produced activated carbon. The maximum CO 2 adsorption capacity obtained in this study was 5.1573 mmol g −1 . This result could be related to the higher amount of microporous present in the activated carbon that facilitates the access of CO 2 to the active sites at the pores of activated carbon. • Tea twigs have a potency to be used as a precursor for activated carbon. • Synthesis of activated carbon derived from tea twigs has been conducted using KOH. • The specific surface area was measured using BET method. • The best activation process was obtained at activator concentration 40 % and a ratio of KOH and carbon of 4:1. • The highest CO 2 adsorption capacity of activated carbon was 5.3623 mmol g −1