Carbon dioxide adsorbents from flame-made diesel soot nanoparticles

Gerardo D J Guerrero Peña; K Suresh Kumar Reddy; Anish Mathai Varghese; Azhagapillai Prabhu; Aasif A Dabbawala; Kyriaki Polychronopoulou; Mark A Baker; Dalaver Anjum; Gobind Das; Cyril Aubry; Mohamed I Hassan Ali; Georgios N Karanikolos; Abhijeet Raj; Mirella Elkadi

doi:10.1016/j.scitotenv.2022.160140

Carbon dioxide adsorbents from flame-made diesel soot nanoparticles

Sci Total Environ. 2023 Feb 10;859(Pt 1):160140. doi: 10.1016/j.scitotenv.2022.160140. Epub 2022 Nov 12.

Authors

Affiliations

¹ Department of Chemistry, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates. Electronic address: gerardo.pena@ku.ac.ae.
² Department of Chemical Engineering, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates; Center for Catalysis and Separation (CeCaS), Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates.
³ Department of Chemistry, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates.
⁴ Department of Mechanical Engineering, Khalifa University, P.O. Box 127788, Abu Dhabi 127788, United Arab Emirates.
⁵ Center for Catalysis and Separation (CeCaS), Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates; Department of Mechanical Engineering, Khalifa University, P.O. Box 127788, Abu Dhabi 127788, United Arab Emirates.
⁶ The Surface Analysis Laboratory, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford GU2 4DL, UK.
⁷ Center for Catalysis and Separation (CeCaS), Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates; Department of Physics, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates.
⁸ Department of Physics, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates.
⁹ Electron Microscopy Core Labs, Khalifa University, P.O. Box 127788, Abu Dhabi 127788, United Arab Emirates.
¹⁰ Department of Chemical Engineering, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates; Center for Catalysis and Separation (CeCaS), Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates; Research and Innovation Center on CO(2) and H(2) (RICH), Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates; Department of Chemical Engineering, University of Patras, 26500 Patras, Greece.
¹¹ Department of Chemical Engineering, Indian Institute of Technology Delhi, Hauz Khas, Delhi, India.
¹² Department of Chemistry, Khalifa University, P.O. Box 127788, Abu Dhabi, United Arab Emirates. Electronic address: mirella.elkadi@ku.ac.ae.

PMID: 36379328
DOI: 10.1016/j.scitotenv.2022.160140

Abstract

Carbon dioxide (CO₂) is the top contributor to global warming. On the other, soot particles formed during fuel combustion and released into the atmosphere are harmful and also contribute to global warming. It would therefore be highly advantageous to capture soot and make use of it as a feedstock to synthesize carbon-based materials for applications such as carbon dioxide adsorption. In this work, flame-made diesel soot nanoparticles were used to produce a variety of activated carbons by combined oxidative treatment with hydrogen peroxide (H₂O₂) and potassium hydroxide (KOH), and their performance towards CO₂ adsorption was evaluated. The effect of the chemical activation of soot with H₂O₂ for different reaction times and with KOH on the physicochemical properties of the activated carbons was investigated and compared to fresh soot. Interestingly, hollow aggregates of carbonaceous nanoparticles of a high interplanar distance, reduced polycyclic aromatic hydrocarbons (PAH) size, shorter PAH stacks, mesoporous structure, and a high content of oxygen functionalities along with other structural defects in PAHs were obtained in the synthesized activated carbons. Among the various analysis techniques employed, Raman spectroscopy indicated that the I_D/I_G ratio in soot decreased after simultaneous chemical treatment, though it did not indicate any enhancement in the graphitic character since the carbonyl and carboxylic containing PAHs and monovacancies (which cause defects in PAHs) also contribute to the increase in the intensity of the graphitic band. The activated carbons possessed promising CO₂ adsorption capacities, adsorption kinetics and CO₂/N₂ selectivity. For example, one of the activated carbons, following H₂O₂ treatment for 9 h and a subsequent KOH activation, exhibited a CO₂ adsorption capacity of 1.78 mmol/g at 1 bar and 25 °C, representing an increase of 161 % in capacity as compared to fresh soot. Hollow aggregates of carbonaceous nanoparticles consisting of shorter PAHs with a larger number of defects led to enhanced CO₂ adsorption rate and CO₂/N₂ selectivity on activated carbons.

Keywords: Activated carbon; Activation; CO(2) adsorption; Carbon capture; Carbon dioxide; Flame; H(2)O(2); KOH; Soot.

MeSH terms

Adsorption
Carbon Dioxide* / analysis
Charcoal / chemistry
Hydrogen Peroxide / analysis
Polycyclic Aromatic Hydrocarbons* / analysis
Soot

Substances

Carbon Dioxide
Soot
Hydrogen Peroxide
Charcoal
potassium hydroxide
Polycyclic Aromatic Hydrocarbons