Streamlined physical activation of Pistacia terebinthus shells: carbonization and activation kinetic studies
Neda Asasian‐Kolur, Seyedmehdi Sharifian, Christian Jordan, Reyhane Aghaei Dinani, Björn Wellscheid, Karin Föttinger, Michael Harasek
Abstract
This study examines the physical activation of Pistacia terebinthus shells—an underutilized biomass—using CO 2 and H 2 O, highlighting a single-reactor, energy-efficient process that eliminates intermediate cooling and reheating, reducing energy consumption by ∼30 %. Activation temperature (700–900 °C), carbonization temperature (300–500 °C), and activating agent concentration (volume ratio of activating gas to inert carrier, 1:4 to 4:1) were optimized for porosity and yield. Steam activation at 800 °C (H 2 O:N 2 = 1:1) produced the highest surface area (1173 m 2 /g) and mesoporosity (70 %), outperforming CO 2 activation, which favored microporosity. Carbonization kinetics, modeled using the Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods, exhibited a two-phase activation energy trend over the conversion range of 0.10–0.45. Activation kinetics followed a zero-order model, with H 2 O exhibiting a lower activation energy (64.8 kJ/mol) than CO 2 (117.2 kJ/mol), indicating higher reactivity. • Streamlined activation by removing excess cooling and reheating, saving 30 % energy. • H 2 O activation boosts mesopores and surface area, while CO 2 favors microporosity. • Activation energy in carbonization drops then rises, indicating structural change. • H 2 O's lower activation energy indicating steam's higher reactivity with carbon. • Pistacia terebinthus shells: a novel renewable source for active carbon production.