The influence of urea formaldehyde resins on pyrolysis characteristics and products of wood-based panels

Abstract

In China each year, large amounts of wood-based panels are consumed and abandoned. These are huge resources for energy recovery and materials reuse. In order to study the influence of urea formaldehyde resin (UF) resin on waste wood-based panels during pyrolysis, thermobalance experiments together with the evolution of main gaseous products of wood, wood-based panels, and UF resins were carried out and analyzed by TG-FTIR. Elementary and GC-MS analyses were also done to study the characteristics of solid and liquid products. Results from TG and DTG analyses indicated that UF resin used in wood-based panels accelerated the degradation rate of wood-based panels at lower temperature; however the resin inhibited the degradation of wood-based panels over the later stage at higher temperatures. Compared with solid wood, the higher intensity and earlier releasing time of HNCO and NH3 in wood board revealed that the release of nitric gases is mainly due to the presence of UF resin, especially between 180 °C and 320 °C. Mass loss of hydrogen is significantly inhibited by UF resin, and nitrogen is quite stable in the char. The influence of UF resin on pyrolysis liquids of wood-based panels is mainly on nitrogen compounds and ketones rather than aldehydes and esters, which is probably due to the chemical reactions of UF resin with lignin constituent in wood.