Abstract
A comparison of moisture loss from Pinus radiata sapwood by conventional forced air-drying and a novel supercritical carbon dioxide (scCO2) dewatering process has been examined in situ using magnetic resonance microimaging. Air-drying results in the nonuniform removal of moisture within the wood volume, leading to a dry core and wet perimeter where water evaporated, whereas the scCO2 dewatering process resulted in moisture expulsion more uniformly throughout the volume of the specimen, especially so within the earlywood.
Acknowledgments
The assistance of Sabine Voll from the Lehrstuhl für Experimentelle Physik V (EP5-Biophysik) at Universität Würzburg in ensuring the timely supply of liquid gases and various laboratory apparatus is greatly appreciated. Hank Kroese of Scion is thanked for the preparation and regular supply of fresh samples of New Zealand-grown P. radiata to the lab at Universität Würzburg. Dr. Meder acknowledges the travel funding assistance from the JW Gottstein Trust.
References
Almeida, G., Gagné, S., Hernández, R.E. (2007) A NMR study of water distribution in hardwoods at several equilibrium moisture contents. Wood Sci. Technol. 41:293–307.10.1007/s00226-006-0116-3Search in Google Scholar
Araujo, C.D., MacKay, A.L., Hailey, J.R.T., Whittall, K.P., Le, H. (1992) Proton magnetic resonance techniques for characterization of water in wood: application to white spruce. Wood Sci. Technol. 26:101–113.10.1007/BF00194466Search in Google Scholar
Behr, V., Schmid, M., Franich, R.A., Meder, R. (2013) An advanced, integrated large-volume, high-pressure autoclave and 1H/13C double-tuned resonator for chemistry and materials NMR spectroscopy and microscopy investigations. Concepts Magn. Reson. B. Magn. Reson. Eng. 43B:49–58.10.1002/cmr.b.21233Search in Google Scholar
Callaghan, P.T. Principles of Nuclear Magnetic Resonance Microscopy. Clarendon Press, Oxford, UK, 1991.Search in Google Scholar
Callaghan, P.T., Franich, R.A., Hill, S.J., Newman, R.H. (2008) Properties of cell walls prepared using supercritical fluids. In: International Academy of Wood Science 2008 Meeting, The Linnean Society of London, London, May 29–30, 2008. Available at: http://iaws-web.org/files/file/2008-London-S.J.Hill.ppt. Accessed December 3, 2013.Search in Google Scholar
Donaldson, L.A., Grace, J., Downes, G.M. (2004) Within-tree variation in anatomical properties of compression wood in radiata pine. IAWA J. 25:253–271.10.1163/22941932-90000364Search in Google Scholar
Dvinskikh, S.V., Henriksson, M., Berglund, L.A., Furó, I. (2011) A multinuclear magnetic resonance imaging (MRI) study of wood with absorbed water: estimating bound water concentration and local wood density. Holzforschung 65:103–107.10.1515/hf.2010.121Search in Google Scholar
Ernst, R.R., Anderson, W.A. (1966) Applications of FT spectroscopy to magnetic resonance. Rev. Sci. Instrum. 37:93–98.10.1063/1.1719961Search in Google Scholar
Evans, R. (1994) Rapid measurement of the transverse dimensions of tracheids in radial wood sections from Pinus radiata. Holzforschung 48:168–172.10.1515/hfsg.1994.48.2.168Search in Google Scholar
Fantazzini, P., Maccotta, A., Gombia, M., Garavaglia, C., Brown, R.J.S., Brai, M. (2006) Solid-liquid nuclear magnetic resonance relaxation and signal amplitude relationships with ranking of seasoned softwoods and hardwoods. J. Appl. Phys. 100:074907.10.1063/1.2354322Search in Google Scholar
Felby, C., Thygessen, L., Kristensen, J.B., Jørgensen, H., Elder, T. (2008) Cellulose-water interactions during enzymatic hydrolysis as studied by time domain NMR. Cellulose 15:703–710.10.1007/s10570-008-9222-8Search in Google Scholar
Franich, R.A., Gallagher, S.S., Kroese, H.W. (2010) Improvements related to wood drying. NZ Patent 582932. 46 pp.Search in Google Scholar
Franich, R.A., Gallagher, S.S., Kroese, H.W. (2013) Wood drying. US Patent 8,578,625. 29 pp.Search in Google Scholar
Franich, R.A., Gallagher, S.S., Kroese, H.W. (2014) Dewatering green sapwood using carbon dioxide cycled between supercritical fluid and gas phase. J. Supercr. Fluids 89:113–118.10.1016/j.supflu.2014.02.019Search in Google Scholar
Glover, P.M., Aptaker, P.S., Bowler, J.R., Ciampi, E., McDonald, P.J. (1999) A novel high gradient permanent magnet for the imaging of planar thin films. J. Magn. Reson. 139:90.10.1006/jmre.1999.1772Search in Google Scholar
Haase, A., Frahm, J., Matthaei, D., Hänicke, W., Merboldt, K.D. (1986) FLASH imaging: rapid NMR imaging using low flip angle pulses. J. Magn. Reson. 67:258–266.10.1016/0022-2364(86)90433-6Search in Google Scholar
Hall, L.D., Rajanayagam, V. (1986) Evaluation of the distribution of water in wood by use of three dimensional proton NMR volume imaging. Wood Sci. Technol. 20:329–333.10.1007/BF00351585Search in Google Scholar
Kininmonth, J.A. (1991) Wood-water relationships. In: Properties and Uses of New Zealand Radiata Pine. Eds. Kininmonth, J.A., Whitehouse, L.J. New Zealand Ministry of Forestry, Forest Research Institute.Search in Google Scholar
MacMillan, M.B., Schneider, M.H., Sharp, A.R., Balcom, B.J. (2002) Magnetic resonance imaging of water concentration in low moisture content wood. Wood Fiber Sci. 34:276–286.Search in Google Scholar
MacMillan, B., Veliyulin, E., Lamason, C., Balcom, B.J. (2011) Quantitative magnetic resonance measurements of low moisture content wood. Can. J. For. Res. 41:2158.10.1139/x11-081Search in Google Scholar
Meder, R., Franich, R.A., Callaghan, P.T. (1999) 11B magnetic resonance imaging and MAS spectroscopy of trimethylborate-treated radiata pine wood. Solid State Nucl. Magn. Reson. 15:69–72.10.1016/S0926-2040(99)00048-XSearch in Google Scholar
Meder, R., Codd, S.L., Franich, R.A., Callaghan, P.T., Pope, J.M. (2003) Observation of anisotropic water movement in Pinus radiata D. Don wood using magnetic resonance micro-imaging. Holz Roh Werkst. 61:251–256.10.1007/s00107-003-0400-ySearch in Google Scholar
Nanassy, A.J. (1973) Use of wide line NMR for measurement of moisture content in wood. Wood Sci. 5:187–193.Search in Google Scholar
Nanassy, A.J. (1974) Water sorption in green and remoistened wood studied by the broad-line component of the wide line NMR spectrum. Wood Sci. 7:61–68.Search in Google Scholar
Pang, S., Wiberg, P. (1998) Model predicted and CT scanned moisture distribution in a Pinus radiata board during drying. Holz Roh Werkst. 56:9–14.10.1007/s001070050256Search in Google Scholar
Riggin, M.T., Sharp, A.R., Kaiser, R. (1979) Transverse NMR relaxation of water in wood. J. Appl. Polym. Sci. 23:3147–3154.10.1002/app.1979.070231101Search in Google Scholar
Rosenkilde, A., Glover, P. (2002) High resolution measurement of the surface layer moisture content during drying of wood using a novel magnetic resonance imaging technique. Holzforschung 56:312–317.10.1515/HF.2002.050Search in Google Scholar
Telkki, V.V., Yliniemi, M., Jokisaari, J. (2013) Moisture in softwoods: fiber saturation point, hydroxyl site content, and the amount of micropores as determined from NMR relaxation time distributions. Holzforschung 67:291–300.10.1515/hf-2012-0057Search in Google Scholar
Thygesen, L.G. (1996) PLS calibration of NMR free induction decay for determining moisture content and basic density of softwood above fibre saturation. Holzforschung 50:434–436.Search in Google Scholar
Thygesen, L.G., Elder, T. (2008) Moisture in untreated, acetylated, and furfurylated Norway spruce studied during drying using time domain NMR. Wood Fiber Sci. 40:309–320.Search in Google Scholar
Vergeldt, F.J., van Dalen, G., Duijster, A.J., Khalloufi, S., van Vliet, L.J., Van As, H., van Duynhoven, J.P.M., van der Sman, R.G.M. (2014) Rehydration kinetics of freeze-dried carrots. Innov. Food Sci. Emerg. Technol. 24:40–47.10.1016/j.ifset.2013.12.002Search in Google Scholar
Wang, P.C., Chang, S.J. (1986) Nuclear magnetic resonance imaging of wood. Wood Fiber Sci. 18:308–314.Search in Google Scholar
Xu, Y., Araujo, C.D., MacKay, A.L., Whittall, K.P. (1996) Proton spin-lattice relaxation in wood – T1 related to local specific gravity using a fast exchange model. J. Magn. Reson. Ser. B 110:55–64.10.1006/jmrb.1996.0007Search in Google Scholar
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