Characterization of Wood Liquefaction Oil for Adhesive Production Yusuf Celikbag, Brian K. Via. School of Forestry and Wildlife Science, Auburn University, Auburn, AL., USA. Wood Adhesive Conference - 10/10/2013
Outline Introduction Problem statement and motivation Materials and Methods Results and Discussion Conclusion
Introduction Phenolic resins are widely used in industrial applications due to their excellent thermal degradation resistance, low electrical conductivity, and high impact resistance In addition, the relative low price and high availability of phenolics makes this group of adhesives an attractive option for high volume applications. The wood products industry currently constitutes approximately half of U.S. phenolic resin consumption, with the remainder primarily utilized in the automotive and electronics industries
Introduction The wood products industry mainly uses phenolic resins in the form of phenol formaldehyde (PF). More than 70% of the PF resins are used in the forest products industry. PF resins are the dominant adhesive used by wood composite manufacturers. The PF resin industry is valued at approximately $2.3 billion USD in North America and $10 billion USD worldwide. http://ajigunturgeni.blogspot.com/2009/12/polymers-and-plastics-introduction.html http://contest.techbriefs.com/2013/entries/sustainable-technologies/3489
Problem Statement and Motivation Phenolic adhesives have come under scrutiny due to the propensity of free formaldehyde to off-gas into the surrounding environment, causing negative health effects to sensitive individuals Global demand for phenol 9,000 KT/annual. More than 95% of phenol is produced from petroleum-derived The world primary source for chemicals is petroleum. Using petroleum in such a large volume creates significant problems: diminishing petroleum reserves, disturbing ecological balance, promoting the greenhouse effect, etc. Nashawi, I. S.; Malallah, A.; Al-Bisharah, M. 2010. Energy Fuels 24:1788-1800. DOI: 10.1021/ef901240p http://www.essentialchemicalindustry.org/chemicals/phenol.html
Problem Statement and Motivation Biomass could be an alternative to petroleum. U.S. Department of Energy (DOE) and U.S. Department of Agriculture (USDA) have priority for the development of bioenergy and bioproducts for the U.S to reduce our dependency on foreign petroleum. DOE and USDA aim to replace 18% of the current U.S. chemical commodities from biomass by 2020, and 25% by 2030. Perlack, R.D., Wright, L.L., Turhollow, A.F., Graham, R.L., Stokes, B.J., Erbach, D.C., 2005. Biomass as a Feedstock for a Bioenergy and Bioproducts Industry: The Technical Feasibility of a Billion-ton Annual Supply. USDA/DOE, DOE/GO-102005-2135, ORNL/TM-2005/66.
Polymers in Wood DP 10,000 Linear polymer Β-1,4 glocoside bonds Highly branched polymer of phenolpropane units DP 200 Branched polymer D-glucose, D-mannose, D-galactose, D-xylose, L-arabinose Alonso, D.M., Wettstein, S.G., Dumestic, J.A. Bimetallic catalyst for upgrading of biomass to fuels and chemicals. Chem. Soc. Rev., 2012, 41, 8075 8098
Organic Solvent Liquefaction Liquefaction Solvent Catalyst Heat (Cellulose Hemicellulose Lignin) BIO-OIL
Epoxy Resin Modification with Bio-oil HO HO + BIO-OIL OH OH
Epoxy Resin Modification Preliminary Data Thomas J. Robinson. Forest Product Laboratory, Auburn University, Auburn, AL. (Unpublished data).
Experimental Plan Bio-oil Production Epoxy Modification Wood Composite Production
Materials and Methods: Bio-oil Production
Residue Content (%) Residue Analysis: Liquefaction Yield Minimum residue content was obtained from 90 min. liquefaction. Liquefaction Time (min.) The reduction and then increase in residue content at longer residence times reflects a contrast between two reactions in the system, namely hydrolysis and polymerization. Polymerization reactions consist of free radicals that, are first generated during decomposition, but then repolymerized resulting in higher molecular weight and insoluble polymers
Residue Analysis: X-Ray Diffraction The increase in the CrI until 90 min. liquefaction suggests that hemicellulose degradation occurred. As the liquefaction time was prolonged, decrease in CrI was observed which was the indication of cellulose degradation.
Residue Analysis: FT-IR The 1736 cm -1 Carbonyl (C=O) groups (hemicellulose)
Bio-oil Analysis: Hydroxyl (OH) Number Test Method: ASTM 4274-11 Phthalic anhydride reacts with pyridine and imidazole according to equations (1) and (2) Hydroxyl group reacts quantitatively with the complexes I and II to form an ester and one equivalent of titratable acid. The excess phthalic anhydride is hydrolyzed with water to give two equivalents of titratable acid. Carey, M. A.; Wellons, S. L.; Elder, D. K. Rapid Method for measuring the hydroxyl content of polyurethane polyols. Journal of Cellular Plastic. January Februray 1984.
Bio-oil Analysis: Hydroxyl (OH) Number Liquefaction time had significant effect on OH numbers (p<0.0001) All bio-oils contained a large number of OH number. Decrease in OH numbers is due to oxidation reactions of EG. Increase in OH numbers is due to solvolysis of wood polymers.
Bio-oil Analysis: FT-IR 1736 cm -1 Carbonyl (C=O) groups 3293 cm -1 C-OH stretching
Bio-oil Analysis: GC/MS
Conclusion Southern yellow pine was successfully liquefied by ethylene glycol with acid catalyst at 150 ᵒC. The effect of liquefaction time on bio-oil and residue formation was investigated. Liquefaction time showed significant effect on hydroxyl number; however, liquefaction yield did not show significant change with respect to liquefaction time. Hydroxyl analysis showed that all bio-oils had a large number of OH number. Highest OH number and liquefaction yield was obtained in 120 min. liquefaction. XRD and FTIR analysis of residues showed that hemicellulose degradation took place in the early stage of liquefaction. Prolonged liquefaction time caused some degree of cellulose degradation. Levoglucosenone and phenolic formation were observed in 120 and 150 min. liquefaction in GC/MS results.
Future Work 31 P-NMR will be performed to characterize the OH groups. Epoxy resin will be modified with bio-oils, and then wood composite will be produced. Effect of OH functionality on epoxy curing and wood composite performance will be investigated.
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