posters 5th Asia-Pacific NMR Symposium 2013

Water distribution changes in six wood species after supercritical carbon dioxide dewatering. (#133)

Stefan Hill 1 , David Sandquist 1 , Roger Meder 2 , Volker Behr 3
  1. Scion, Rotorua, New Zealand
  2. Forest Genetics, Genomics and Phenomics, CSIRO, Brisbane, Queensland, Australia
  3. Experimentelle Physik V (Biophysik), Physikalisches Institut Universitaet Wuerzburg, Wuerzburg, Am Hubland, Germany

Specimens of sapwood taken from four softwoods and two hardwoods; Monterey cypress (Cupressus macrocarpa), Monterey pine (Pinus radiata), Norway spruce (Picea abies), Sitka spruce (Picea sitchensis), shining gum (Eucalyptus nitens), and mountain ash (Eucalyptus regnans), were subjected to carbon dioxide cycled between the supercritical phase at pressures exceeding 77 bar and gaseous phase at 1 bar, at temperatures exceeding 31 °C. Pressure and phase cycling of carbon dioxide has been found to lower the water content in wood by a process termed as dewatering. The number of cycles and the overall efficiency of the dewatering of wood, down to approximately fibre-saturation point, was found to be species dependent. The effect of dewatering on the quantity and spatial distribution of water was measured by 1H imaging at 300 MHz using Single Pulse and 2D FLASH sequences.