Development of Nanoporosity on a Biomass Combustion Ash-derived Carbon for CO₂ Adsorption

Abstract

Carbonaceous adsorbents are one of the most widely-used materials used for the removal of chemical species in gaseous and aqueous media. However, the route from precursor to activated carbon is riddled with myriad techniques and steps, that entail additional costs. Such expenses could be minimized via waste valorization e.g. biomass combustion bottom ash which has been used in this work. In order to develop surface nanoporosity, the waste-derived carbon was thermally treated, increasing the CO2 adsorption capacity by nearly twofold and thus, producing a cost-effective sorbent for postcombustion CO2 capture. The effectiveness of such "unconventional" activation route has been verified using Scanning Electron Microscopy, Fourier-Transform Infrared Spectroscopy as well as Proximate Analysis and the CO2 adsorption data obtained via Thermogravimetric Analysis (TGA). The proposed material and method could serve as a viable alternative to the current methods for decarbonization of the UK power sector through in-situ waste valorization.

Impact of Production Pathway on Nanoporosity of Carbonaceous Sorbents for CO2 Adsorption

“…Further, Table I corroborates the hypothesis of PVA decomposition upon activation (potentially propagating lesser mechanical stability of the P-A samples). Regardless, the higher VOC content of the pellets compared to their powder-form analogues [6] indicates presence of PVA within the materials.…”

“…The procedure for deriving the virgin (i.e. not activated) carbon was described in our previous work [5], whereas the activation of the samples (powders and pellets) followed a pathway described in [6].…”

“…Following this pathway, the virgin carbon pellet (VCP) and the activated-then-pelletized (A-P) samples were produced. The pelletized-then-activated (P-A) sample was obtained by activating the VCP pellets as per [6]. The adsorption capacity of the nanoporous materials was evaluated via TGA (Mettler Toledo TGA 2), the surface morphology was examined on a Scanning Electron Microscope (LEO 1455VP), the surface functional groups were studied using a Fourier-Transform Infrared Spectroscope (Shimadzu IRSpirit), whereas Proximate Analysis was conducted as per ASTM D3172 [18].…”

“…Consequently, valorization of this waste as a precursor for the synthesis of nanoporous adsorbents for CO2 capture could help alleviate the burden of ash management, whilst simultaneously providing the grounds for cost-effective insitu decarbonization of the biomass firing power plants. Our previous works have served as the proof of concept, successfully demonstrating the feasibility of extraction of carbonaceous nanoporous sorbents [5] followed by development of pronounced porosity [6]. However, industrial deployment requires a significant increase in the size of the adsorbent (i.e.…”