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

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.

Synthesis and Characterization of Bio-oil-Based Self-Curing Epoxy Resin

“…Bio-oils were produced by the HTL process according to the method reported by Celikbag et al Two types of bio-oils were used in epoxy synthesis: (i) bio-oil produced in water medium at 350 °C (W-HTL-bio-oil) and (ii) bio-oil produced in water/ethanol medium at 300 °C (WE-HTL-bio-oil). The HTL temperature was selected based on the highest bio-oil yield which was obtained at 350 and 300 °C when water and water/ethanol were used as the liquefying solvent, respectively .…”

“…Bio-oil is a term used in the literature for “liquefied biomass” produced by decomposition of lignocellulosic biomass through thermomechanical liquefaction processes, and it could be used as a biopolyol as an alternative to BPA to synthesize biobased epoxy resin because of its high hydroxyl number (OHN). There are mainly three liquefaction processes to obtain bio-oil: (i) organic solvent liquefaction (OSL), the liquefaction of lignocellulosic biomass using organic solvents such as ethylene glycol at moderate temperature; (ii) fast pyrolysis (FP), the liquefaction in the absence of oxygen and solvent at elevated temperatures; and (iii) hydrothermal liquefaction (HTL), the liquefaction using water at high temperature and pressure . It is very important to note that even if the liquid product from OSL, FP, and HTL processes is defined as bio-oil, the properties of the bio-oils (OHN, molecular weight, and chemical composition) are different from each other.…”

“…However, using ethanol as a cosolvent along with the water can increase the bio-oil yield up to 65 wt % . Our group has recently studied the effect of ethanol and HTL temperature on the OH and carbonyl (CO) groups in HTL-bio-oil and found that addition of ethanol to the HTL process increased the total OHN of HTL-bio-oil yet decreased the concentration of phenolic type of OH groups . The total OHN of HTL-bio-oil was found to be in the range of 4.0–8.5 mmol/g, which suggests that HTL-bio-oil could be utilized as a biopolyol in epoxy synthesis …”

Lignin Hydrothermal Liquefaction into Bifunctional Chemicals: A Concise Review

“…However, the efficiency depends on the Ni/Al ratio and other promoter metallic composition of the catalysts. [38,[42][43][44]; agricultural waste [15]; Loblolly pine [45]; Pinewood [25].…”

Aspen plus simulation to predict steady state performance of biomass‐CO2 gasification in a fluidized bed gasifier

“…cellulosic ethanol) or thermochemical (e.g. gasification, combustion, pyrolysis, and hydrothermal liquefaction) routes . Gasification is the process of partial combustion of biomass to produce a high calorific value gas, syngas, which is a combination of CO, H 2 , CH 4 , and CO 2 along with tar (condensable organic compounds) and other contaminants (NH 3 , H 2 S, HCN, etc.)…”