MSE Special Seminar: Microwave wood modification technology and its applications
Monday, May 6, 2019
0108, EGR (Glenn L. Martin Hall)
Speaker: Grigory Torgovnikov, Ph.D., Honorary Fellow of the School of Ecosystem and Forest Sciences, University of Melbourne
Title: Microwave wood modification technology and its applications
Low permeability of many wood species causes problems during timber manufacturing including very long drying times, large material losses after drying, and expensive drying processes. Impregnating low permeability timber with preservatives and resins is extremely difficult. In the pulp and paper industry, low permeability wood results in shallow chemical penetration, requires the use of small-sized chips, high chemical usage, and high energy consumption. New microwave (MW) technology provides solutions to many of these problems. Experimental studies into MW wood modification at 0.922, 2.45 and 5.8 GHz revealed a dramatic increase in wood permeability when MW power is applied in the range of 250 to 1200 MJ/m3.
Physical and mechanical characteristics of modified wood also alter. MW process parameters were developed to provide reproducible levels of timber modification taking into consideration variations in species, size, and moisture content which provided a sound foundation for the new technology. Research results demonstrate that this technology could be applied to any wood species.
The following commercial applications were identified: the treatment of refractory wood species with preservatives, rapid drying of hardwoods, growth and drying stress relief in timber, and manufacturing of two new wood materials Torgvin and Vintorg. Improvements in wood pulping properties could be obtained through MW modification of sawn timber, logs, and chips. Additionally, the use of MW modified wood has significant advantages for superwood manufacturing: radical reduction of delignification time, possibility to effectively use low permeable species, large timber cross section (up to 250x 250 mm), reduction of chemical consumption, and improved environmental performance.
The cost of AU$28 to $69/m3 for MW wood conditioning is acceptable to the industry and provides good commercial opportunities.
Dr. Torgovnikov was born and received his education in the Soviet Union (now Russia). He completed a PhD degree and a Doctor of Technical Sciences degree at the Central Scientific Research Institute of Timber Industry and Power Engineering (TsNIIME, Moscow) and spent 20 years working in this institution as the Head of Microwave Technology Group. In 1995 he was invited by the University of Melbourne (Australia) to lift up the level of research in microwave (MW) wood technology. Since that time he has been working at the University of Melbourne. He is also a Correspondent - Member of Russian Academy of Natural Sciences (Forest Science Department).
Torgovnikov has published 4 books, 89 papers and has got 36 patents in the field of wood technology. The most known book Dielectric properties of wood and wood-based materials.
Currently, he is an Honorary Fellow of the School of Ecosystem and Forest Sciences at the University of Melbourne and is continuing to pursue scientific research in the field of microwave processing of wood, wood-based materials, and agricultural materials.