Pd/C catalyzed transfer hydrogenation of pyrolysis oil using 2-propanol as hydrogen source

Hoda Shafaghat, In Gu Lee, Jungho Jae, Sang Chul Jung, Young Kwon Park

Research output: Contribution to journalArticlepeer-review

45 Scopus citations

Abstract

The hydrodeoxygenation of guaiacol, as a pyrolysis oil representative model compound, was carried out over a Pd/C catalyst using a liquid hydrogen source of 2-propanol (2-PrOH) as an alternative to hydrogen gas. The effects of reaction temperature (190–230 °C), initial nitrogen pressure (0.5–12 bar), Pd loading amount (5 and 10 wt%), catalyst content (0.2–0.5 g), and reaction time (1–6 h) on the product distribution were investigated. Generally, 2-methoxycyclohexanone (two-oxygen-containing compound), methoxycyclohexane, cyclohexanol, 2-methyl-2-cyclohexen-1-ol, 2-cyclopenten-1-one, cyclohexanone, 2-cyclohexen-1-ol, phenol (one-oxygen-containing compounds), and (1-methylpropyl)cyclohexane (oxygen-free compound) were produced during the transfer hydrogenation of guaiacol in 2-PrOH. The feasibility of using different types of alcohols, primary (methanol, ethanol, 1-propanol, and 1-butanol) and secondary (2-propanol, and 2-butanol), as a substitute for hydrogen gas in the guaiacol hydrodeoxygenation process was examined, and it was found that only the secondary alcohols could act as a H-donor for the guaiacol transformation over Pd/C. Both 2-PrOH and 2-butanol (2-BuOH) led to almost complete conversion of guaiacol (≥98.5 wt%). However, complete deoxygenation of guaiacol to (1-methylpropyl)cyclohexane only occurred when 2-PrOH was used as the reducing agent. Finally, the transfer hydrogenation of raw pyrolysis oil was carried out over Pd/C at 230 °C and an initial nitrogen pressure of 8 bar for 4 h using 2-PrOH and 2-BuOH as the H-donors. Although 2-PrOH was the most efficient H-donor for guaiacol hydrodeoxygenation, 2-BuOH led to a higher level of deoxygenation of pyrolysis oil, resulting in a greater heating value.

Original languageEnglish
Article number119986
JournalChemical Engineering Journal
Volume377
DOIs
StatePublished - 1 Dec 2019

Keywords

  • 2-Propanol (2-PrOH)
  • Alkylated cyclohexane
  • Guaiacol
  • H-donor
  • Pyrolysis oil upgrading
  • Transfer hydrogenation

Fingerprint

Dive into the research topics of 'Pd/C catalyzed transfer hydrogenation of pyrolysis oil using 2-propanol as hydrogen source'. Together they form a unique fingerprint.

Cite this