Investigation into role of CO₂ in two-stage pyrolysis of spent coffee grounds

Youkwan KIM, Jechan LEE, Haakrho YI, Yiu Fai TSANG, Eilhann E. KWON

Research output: Contribution to journalArticle

Abstract

As a way of improving process efficiency of pyrolysis of waste biomass, the effect of carbon dioxide (CO₂) on pyrolysis of spent coffee grounds (SCGs) was examined using a two-stage pyrolysis reactor consisting of a region with increasing temperature and an isothermal region. It was experimentally validated that CO₂ accelerates thermal cracking of organic compounds formed during the pyrolysis of SCGs. The expedited thermal cracking attributed to employing CO₂ in pyrolysis of SCGs led to changing pyrolytic products in gas, liquid, and solid phases. The production of gaseous carbon monoxide was increased when using CO₂ as the pyrolysis medium. In liquid pyrolytic products, the formation of phenolic compounds was hindered in the CO₂-assited pyrolysis. Biochar morphology (solid pyrolytic product) was also changed with different pyrolysis environments. This study shows that CO₂ can help improve applicability of pyrolysis of waste biomass by modifying three phase pyrolytic products in a two-stage pyrolyzer. Copyright © 2018 Elsevier Ltd. All rights reserved.
LanguageEnglish
Pages48-53
JournalBioresource Technology
Volume272
Early online dateOct 2018
DOIs
Publication statusPublished - Jan 2019

Fingerprint

Coffee
coffee
pyrolysis
Pyrolysis
Biomass
liquid
biomass
Liquids
phenolic compound
Carbon Monoxide
Organic compounds
Carbon Dioxide
carbon monoxide
Carbon monoxide
organic compound
Carbon dioxide
carbon dioxide
Gases
product

Citation

Kim, Y., Lee, J., Yi, H., Tsang, Y. F., & Kwon, E. E. (2019). Investigation into role of CO₂ in two-stage pyrolysis of spent coffee grounds. Bioresource Technology, 272, 48-53. doi: 10.1016/j.biortech.2018.10.009

Keywords

  • Waste-to-energy
  • Biomass valorization
  • Thermo-chemical process
  • Carbon dioxide