CHARACTERIZATION OF LIQUID PRODUCT FOR THE FEASIBILITY ANALYSIS OFPHENOLIC SUBSTANCE RECOVERY FROM PYROLYSIS PROCESS OF WOOD BIOMASS

摘要

Environmental issues related with organic waste disposal have been more important than before and thereare several efforts to convert these wastes into eco-friendly products along with some intentions of materialutilization and energy recovery. Lignin, a polyphenolic component, is one of potential renewable rawmaterials as a substitute for phenols produced from petroleum. Industrial applications of lignin as a chemicalfeedstock have, however, been seriously limited for its low reactivity.Fast pyrolysis technique was attempted to obtain a suitable lignin material as a substitute for phenol, using afluidized-bed reactor at the condition of 300～500°C. Kraft lignin(KL) and milled wood lignin(MWL) werealso separated as comparative materials from same kind of wood, Pinus radiata D. Don, which pyrolyticlignin(PL) is produced from. Because the quality of lignin for industrial application could be determined bythe guidelines based on physico-chemical characteristics, the average molecular weights of lignin sampleswere determined using gel permeation chromatography(GPC), while phenolic hydroxyl groups were analyzedwith gas chromatography, and 13 C-NMR spectra were also applied to observe their structural features.Depending on GPC analysis, PL has lower average molecular weight(MW), about 1200 g mol -1 , comparedwith those of KL and MWL, about 5400 and 7600 g mol -1 , respectively. The polydispersity of PL was alsosmaller than those of KL and MWL. The concentration of phenolic hydroxyl groups of PL was lower than thatof KL, but similar with that of MWL. Comparing with the 13 C-NMR spectrum of MWL, the signal assignedto methoxyl groups was a little weakened in the KL spectrum, but this is even more reduced in the pyrolyticlignin product spectrum. According to the experimental results, PL is considered a homogeneous polymerhaving lower molecular weight and less methoxyl groups than KL with no substantial decrease of phenolichydroxyl group, indicating that there is a possibility of recovering phenolic substances from wood biomass orwood waste through fast pyrolysis process.