The effect of ethanol on hydroxyl and carbonyl groups in biopolyol produced by hydrothermal liquefaction of loblolly pine: (31)P-NMR and (19)F-NMR analysis

Yusuf Celikbag; Brian K Via; Sushil Adhikari; Gisela Buschle-Diller; Maria L Auad

doi:10.1016/j.biortech.2016.04.066

The effect of ethanol on hydroxyl and carbonyl groups in biopolyol produced by hydrothermal liquefaction of loblolly pine: (31)P-NMR and (19)F-NMR analysis

Bioresour Technol. 2016 Aug:214:37-44. doi: 10.1016/j.biortech.2016.04.066. Epub 2016 Apr 19.

Authors

Yusuf Celikbag¹, Brian K Via², Sushil Adhikari³, Gisela Buschle-Diller⁴, Maria L Auad⁵

Affiliations

¹ School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849 USA.
² School of Forestry and Wildlife Sciences, Auburn University, Auburn, AL 36849 USA; Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL 36849 USA; Department of Biosystem Engineering, Auburn University, Auburn, AL 36849, USA. Electronic address: bkv0003@auburn.edu.
³ Center for Bioenergy and Bioproducts, Auburn University, Auburn, AL 36849 USA; Department of Biosystem Engineering, Auburn University, Auburn, AL 36849, USA.
⁴ Department of Biosystem Engineering, Auburn University, Auburn, AL 36849, USA.
⁵ Department of Chemical Engineering, Auburn University, Auburn, AL 36849, USA.

PMID: 27126078
DOI: 10.1016/j.biortech.2016.04.066

Abstract

The goal of this study was to investigate the role of ethanol and temperature on the hydroxyl and carbonyl groups in biopolyol produced from hydrothermal liquefaction of loblolly pine (Pinus spp.) carried out at 250, 300, 350 and 390°C for 30min. Water and water/ethanol mixture (1/1, wt/wt) were used as liquefying solvent in the HTL experiments. HTL in water and water/ethanol is donated as W-HTL and W/E-HTL, respectively. It was found that 300°C and water/ethanol solvent was the optimum liquefaction temperature and solvent, yielding up to 68.1wt.% bio-oil and 2.4wt.% solid residue. (31)P-NMR analysis showed that biopolyol produced by W-HTL was rich in phenolic OH while W/E-HTL produced more aliphatic OH rich biopolyols. Moreover, biopolyols with higher hydroxyl concentration were produced by W/E-HTL. Carbonyl groups were analyzed by (19)F-NMR, which showed that ethanol reduced the concentration of carbonyl groups.

Keywords: (19)F-NMR; (31)P-NMR; Bio-oil; Biopolyol; Hydrothermal liquefaction.

MeSH terms

Biopolymers / isolation & purification*
Ethanol / chemistry*
Hydroxyl Radical
Pinus taeda / chemistry*
Polymers / analysis
Solutions
Solvents / chemistry
Water / chemistry

Substances

Biopolymers
Polymers
Solutions
Solvents
polyol
Water
Hydroxyl Radical
Ethanol