Functional Activated Biocarbons Based on Biomass Waste for CO₂ Capture and Heavy Metal Sorption

Abstract

Inexpensive porous activated biocarbons were prepared from biomass and agriculture waste following the method of thermal and hydrothermal carbonization and activation with superheated water vapor. The activated biocarbons were characterized by nitrogen adsorption–desorption at 77 K, SEM, XRD, Raman spectrometry, FTIR spectroscopy, determination of particle size, and elemental composition by XRF. The specific surface area was in the range of 240–709 m 2 /g, and the total pore volume was from 0.12 to 0.43 cm 3 /g. The percentage of microporosity in activated biocarbons was 89–92%. These activated biocarbons have been used for CO 2 and heavy metal sorption. Activated biocarbons based on pine cones and birch prepared by thermal carbonization and activation with superheated water vapor had the highest ability to capture CO 2 and amounted to 6.43 and 6.00 mmol/g at 273 K, as well as 4.57 and 4.22 mmol/g at 298 K, respectively. The best activated biocarbon was characterized by unchanged stability after 30 adsorption and desorption cycles. It was proved that the adsorption of CO 2 depends on narrow micropores (<1 nm). Activated biocarbons have also been analyzed as effective adsorbents for removing Cu 2+ , Zn 2+ , Fe 2+ , Ni 2+ , Co 2+ , and Pb 2+ ions from aqueous solutions. Activated biocarbons are effective adsorbents for the removal of lead and zinc ions from aqueous solutions.

Exploring the versatile production techniques and applications of nitrogen-doped activated carbon

“…Nitrogen doped activated carbon (NACs) is already produced by scientists from different types of plant waste by various activation methods and they obtained Ndoped AC with high surface area, suitable structure and pore size and huge adsorption capacity for uptake CO2 [16]. The general synthesis principle of Nitrogen doped AC are classified in Chemical or direct activation also this method is known as in-situ synthesis [17], Physical activation [18], and hydrothermal method [13].…”

“…The exploration of novel synthesis methods, coupled with a deeper understanding of its structural and chemical characteristics, opens avenues for even more tailored applications [10]. Ultimately, the multifaceted nature of nitrogen-doped activated carbon positions it as a cornerstone material, contributing significantly to advancements in sustainable technologies and environmental conservation [18].…”