Catalytic co-pyrolysis of industrial hemp stalk and glycerol with HZSM-5 and dolomite: product yields and bio-oil characteristics


Girişen A. R., Özcan H.

Biomass Conversion and Biorefinery, vol.15, no.9, pp.14241-14254, 2025 (SCI-Expanded, Scopus) identifier

  • Publication Type: Article / Article
  • Volume: 15 Issue: 9
  • Publication Date: 2025
  • Doi Number: 10.1007/s13399-024-06467-4
  • Journal Name: Biomass Conversion and Biorefinery
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC
  • Page Numbers: pp.14241-14254
  • Keywords: Catalytic co-pyrolysis, Dolomite, Glycerol, Hemp stalk, HZSM-5
  • Ondokuz Mayıs University Affiliated: Yes

Abstract

This study examined the catalytic fast co-pyrolysis of hemp stalk and glycerol using HZSM-5 and dolomite catalysts to produce diesel-range hydrocarbons. The co-pyrolysis method was used to produce aromatic and aliphatic hydrocarbons (C9–C20) in the diesel fuel range and a high amount of organic phase bio-oil. A bubbling fluidized bed reactor was used for this purpose. The yields and contents of derived bio-oils at different mixing ratios with glycerol (10, 15, and 20 wt.%), different catalysts (HZSM-5 and dolomite), and pyrolysis temperatures (350, 400, 450, 500, and 550 °C) were investigated. The co-pyrolysis results showed that the bio-oil yield improved with glycerol. The highest bio-oil yield (46.82%wt.) was achieved through in situ catalytic co-pyrolysis with glycerol (15%wt.) and dolomite at 550 °C. In addition, in situ catalytic co-pyrolysis with glycerol and dolomite caused a decrease of 48.84% (GC–MS peak area) in oxygenated compounds compared to direct pyrolysis of hemp stalk. The content of catalytic co-pyrolysis bio-oil mainly consisted of aliphatic hydrocarbons in the C12–C20 carbon range, and it also contains a significant amount of ketones, phenols, and alcoholic compounds. In addition, co-pyrolysis with the use of dolomite in the reactor, mostly methyl elaidate, methyl palmitate, 9-octadecene, and (E)- and 8-heptadecene structures were found in the bio-oil. Moreover, the findings presented in this paper can lead to the development of basic, cheap, and sustainable new methods for integrating pyrolysis oil into existing refinery infrastructure.