Products and functional group distributions in pyrolysis oil of chromated copper arsenate (CCA)-Treated wood, as elucidated by gas chromatography and a novel 31P NMR-Based method

Low-temperature pyrolysis offers a feasible option for wood waste management and the recovery of a variety of useful chemicals. In this study, the effect of chromated copper arsenate (CCA) wood preservatives on the yield and composition of various pyrolysis products was investigated over the temperature range of 275-350 degrees C. For this preliminary work, we examined the feasibility of using gas chromatography coupled with either flame ionization detection or mass spectroscopic detection and a novel P-31 nuclear magnetic resonance (NMR) spectroscopic method. Both methods worked well, with the gas chromatographic method being compound-specific and the P-31 NMR method being specific to the functional group (e.g., aliphatic alcohols, total phenols, and carboxylic acids). The present experiments showed that the CCA treatment on wood had a significant effect on the amount of main carbohydrate degradation products of tar. The yield of levoglucosan (LG) from CCA-treated wood increased, while the yields of hydroxyacetaldehyde and hydroxyacetone decreased.