Application of Nanoporous Carbon, Extracted from Biomass Combustion Ash, in CO₂ Adsorption

Abstract

Bioenergy with Carbon Capture and Storage has been regarded as one of the most prominent technologies in the battle against climate change as stated in the latest Intergovernmental Panel on Climate Change reports.However, solid residues generated during the combustion of biomass pose a separate set of environmental and economic challenges that must be addressed. In order to utilise the full potential of this waste stream, an effective nanoporous carbonaceous adsorbent for CO2 capture has been directly prepared via a simple and low-cost extraction technique from industrial-grade biomass combustion bottom ash generated at a UK power plant. The adsorbent characterisation data (via Scanning Electron Microscopy-Energy Dispersive X-ray Spectroscopy as well as Fourier-Transform Infrared Spectroscopy) agrees well with the CO2 adsorption curves obtained through thermogravimetric analysis (TGA). The TGA results have revealed a CO2 adsorption capacity of 0.73 mmol/g at 25 °C and 1 atm under a pure CO2 gas stream, thus, proposing a promising and viable route towards in-situ decarbonisation of the biomass combustion sector in the UK via effective waste valorisation.

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

“…The EDS results are presented in Table I. As seen here, a significant amount of elemental carbon has been lost during the thermal treatment when compared to the parent BA-63-P data [5]. This is to be expected since at elevated temperatures, decomposition of less stable surface functionalities occurs as well as general thermal degradation of the carbonaceous sorbent.…”

“…3 and Fig. 4 due to the SEM analysis being focused on porosity development on the virgin carbon (they are, however, clearly visible in our previous work [5]).…”

“…Industrial-grade biomass combustion bottom ash (BA) was used as the raw material for extraction of virgin carbon (coded name BA-63-P) following the method described in our previous work [5].…”

“…These monetary benefits are of utter importance when considering commercialization of novel separation processes, such as post-combustion carbon capture with solid adsorbents. In our previous work [5], we have derived carbon from biomass combustion bottom ash (avoiding the first carbonization step normally described in waste to AC process literature). In this work, we have built upon our previouslyproduced sorbent, increasing its porosity, though, not by traditional activation.…”

Synthesis of Nanoporous Type A and X Zeolite Mixtures from Biomass Combustion Fly Ash for Post-Combustion Carbon Capture

“…The wave number region of 1090 -900 cm -1 is related to the internal asymmetric stretching vibrations of the Si-O-T bridges [12], [16] where T can be either Si or Al. The shift of this frequency to 1005 cm -1 from around 1100 cm -1 for pure silica is due to a decrease in the framework Si/Al [20] as the length of the Al-O bond is 1.73 Å, whereas the Si-O bond is 1.62 Å. The band seen at 675 cm -1 is related to the symmetric stretching of Si-O-Al bridges, whilst the band at 551 cm -1 is characteristic of the symmetric Si-O-Si stretching and O-Si-O bending vibrations of the double rings [12], [21].…”