Customizing high-performance molten salt biochar from wood waste for CO2/N2 separation

Mingzhe Sun, Xiefei Zhu*, Chunfei Wu, Ondrej Masek, Chi-Hwa Wang, Jin Shang, Yong Sik Ok, Daniel C.W. Tsang

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

22 Citations (Scopus)

Abstract

Engineered biochar derived from wood waste pyrolysis in molten salts were developed for effective CO2/N2 separation. The production conditions were customized to obtain the biochar with high CO2 capture capacity and CO2/N2 selectivity by tuning the type of molten salts (MgCl2-KCl, ZnCl2-KCl, ZnCl2-NaCl-KCl, and K2CO3-Na2CO3-Li2CO3), salt/feedstock ratios (1:1 and 3:1) and pyrolysis temperatures (600 and 800 °C). High temperature (800 °C) and moderate salt loading (salt/feedstock ratio of 1:1) benefited the CO2 adsorption by providing an increased surface area and highly dispersed metal species as adsorption sites. PSL-3-800 and PSL-3-600 (K2CO3-Na2CO3-Li2CO3 biochar) showed the highest CO2 capacity (4.5 mmol g−1, 0 °C, 100 kPa) and the highest CO2/N2 selectivity (28.5), respectively, among the engineered biochar developed in this study. In addition, ZP-3-600 showed the highest selection parameter (S) in both PSA and VSA processes, indicating the promising CO2 capture performance under PSA/VSA conditions. A high recovery rate (89%) of molten salts was achieved. These results suggest a new pathway for upcycling biowaste as eco-friendly and effective adsorbents for gas adsorption and separation.

Original languageEnglish
Article number107319
JournalFuel Processing Technology
Volume234
Early online date26 May 2022
DOIs
Publication statusPublished - Sept 2022

Bibliographical note

Funding Information:
We appreciate the financial support from the Hong Kong Environment and Conservation Fund (Project 104/2021 ) and Hong Kong Green Tech Fund ( GTF202020153 ) for this study. X.Z. thanks the funding of the Fundamental Research Funds for the Central Universities ( WK2090000037 ) and the Hong Kong Scholar Program ( XJ2020022 ). We also acknowledge the equipment support provided by the University Research Facility in Chemical and Environmental Analysis (UCEA) of the Hong Kong Polytechnic University .

Funding Information:
We appreciate the financial support from the Hong Kong Environment and Conservation Fund (Project 104/2021) and Hong Kong Green Tech Fund (GTF202020153) for this study. X.Z. thanks the funding of the Fundamental Research Funds for the Central Universities (WK2090000037) and the Hong Kong Scholar Program (XJ2020022). We also acknowledge the equipment support provided by the University Research Facility in Chemical and Environmental Analysis (UCEA) of the Hong Kong Polytechnic University.

Publisher Copyright:
© 2022 Elsevier B.V.

Keywords

  • Biochar adsorbent
  • Biochar-mineral composite
  • Carbon sequestration
  • CO capture
  • PSA/VSA assessment
  • Waste recycling

ASJC Scopus subject areas

  • General Chemical Engineering
  • Fuel Technology
  • Energy Engineering and Power Technology

Fingerprint

Dive into the research topics of 'Customizing high-performance molten salt biochar from wood waste for CO2/N2 separation'. Together they form a unique fingerprint.

Cite this