Penn State Researches Microwave Pallet Treatment
July 17, 2011
|A collaborative project that involves wood-products, engineers and entomologists from Penn State’s College of Agricultural Sciences is looking for the next big thing when it comes to pallet and packaging treatment to stop the spread of invasive pests.
Existing control measures largely are limited to conventional heat treatment — which involves a slow process of convection heating of the wood material in huge ovens to 56 degrees Celsius for 30 minutes — or the use of methyl bromide. But the use of that chemical as a fumigant is challenged widely because it is classified as an ozone-depleting gas and has been banned in several countries.
“Our research includes a diverse array of experimental data collection and studies on how dielectic heating interacts with wood,” said, Dr. John Janowiak, professor of wood products engineering. “We are evaluating the efficacy of microwave and radio-frequency energy – using both batch and continuous processes – to rapidly sterilize solid-wood packaging materials. These treatments are designed to replace methyl bromide fumigation.”
The work on microwave processes has progressed to the point that a formal submission on the use of microwave energy under ISPM-15 has been recommended for approval to the Standards Committee of the International Plant Protection Convention, noted Kelli Hoover, professor of entomology.
“Assuming our submission passes country consultation, microwaves will be the first alternative treatment adopted under ISPM-15 since it was implemented almost 10 years ago,” she said. “We currently are tweaking the treatment schedule and guidelines for commercial implementation.”
But because radio frequency — also known as RF — has better penetration depth than microwaves, the team is currently focused on developing the efficacy data set and treatment schedule for submission of RF heating for adoption under ISPM-15.
Janowiak predicted the research will expand to other forest-based commodities such as woody biomass, including pulp chips exported for either heating biofuel or fiber pulp recovery.
While phytosanitary control across international boundaries is the primary objective of the research, the team also is analyzing the overall environmental and economic benefits of the competing technologies. Dr. Charles Ray, associate professor of wood products operations, is leading life-cycle analysis of the alternatives.
“Stopping the movement of pests and diseases can be done through a number of means,” he said. “However, each potential solution produces different impacts on climate change and sustainability measures, such as carbon dioxide emissions, aquatic ecotoxicity and use of nonrenewable energy, to name just a few.
“Our project is designed to ensure that the analysis presented to the international regulatory bodies includes an assessment of these impacts, as well as the relative cost of each.”
This comprehensive approach to the research has been noted by the international community. According to a press release by Penn State, one leading delegate of the United Nations Food and Agriculture Organization even commented that the Penn State team’s approach may well turn out to be the model by which other regulatory research will be conducted in the future.
This Penn State research has been funded by the USDA Methyl Bromide Transitions Program.
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