Low-temperature hydrothermal carbonization of activated carbon microsphere derived from microcrystalline cellulose as carbon dioxide (CO2) adsorbent

Activated carbon material produced by the low-temperature hydrothermal processes was needed to further decrease the production cost of CO2 adsorbent materials. In this study, we fabricated cellulose hydrochar microspheres (CHM) materials with a relatively low hydrothermal temperature (200 & DEG;C) with prolonged hydrothermal reaction time (48 h) using microcrystalline cellulose as a feedstock. The CHM is then further activated using a thermal and chemical agent. The activated carbon microsphere was then characterized using scanning electron microscopy (SEM), an X-ray diffractometer (XRD), and Fourier transforms infrared (FTIR) spectroscopy. The Brunauer-Emmett-Teller (BET) surface area (SBET) of the thermal activation (ACS) activated carbon was enhanced significantly with further chemical activation with KOH and NaOH, from 589 m2/g to 1334 m2/g and 2296 m2/g, respectively. Moreover, CHONS elemental analysis suggests that the chemical activation process enhances the surface functional group. Increasing textural properties and enrichment of the functional group of the ACS-NaOH and ACS-KOH samples gave a CO2 adsorption capacity up to 7.07 mmol/g after 300 min of contact. This finding enables the possibility of producing cellulose hydrochar microspheres using a low hydrothermal temperature that can be further activated to become CO2 adsorbent materials with great CO2 capture capabilities.& COPY; 2023 Elsevier Ltd. All rights reserved.