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Title: Recycling of treated wood poles

Conference ·
OSTI ID:115329
 [1]
  1. TWT Wood Products, Inc., Alberta (Canada)

There are approximately 150 million utilities poles in service in North America. Of the 3 million poles removed from service each year, many poles still contain a sound and structurally intact core and only the outer layer has deteriorated. Since most of the old poles are treated with either pentachlorophenol or creosote there are limited disposal options available to pole users. The practice of giving old poles away to farmers or other interested parties in falling into disfavour since this practice does not absolve the utility of the environmental liability associated with the treated wood. TWT has commercialised a thermolysis (Pyrolysis) based process capable of removing oil based preservatives from treated wood. The patented process involves: the shaving of the weathered pole exterior; the rapid distillation of oil based preservatives in an oxygen depleted environment; condensation of the vapours; and separation of liquids. TWT has constructed a 30,000 pole per year facility east of Calgary and has provided recycled poles for the construction of two power lines now in use by TransAlta Utilities Corporation, Canada`s largest investor owned electric utility. TWT has tested two thermolysis (Pyrolysis) technologies and has determined that contact thermolysis using a heated auger design performed better and with less plugging than a fast fluid bed reactor. The fluid bed reactor is prone to coke formation and contamination of the oil by fine char particles. Residual PCP concentration in the shavings was reduced from 9500 ppm to 10 ppm. Leachate testing on the char yielded a PCP concentration of 1.43 ppm in the Leachate, well below the EPA standard maximum of 100 ppm.

Research Organization:
National Renewable Energy Lab. (NREL), Golden, CO (United States)
OSTI ID:
115329
Report Number(s):
NREL/CP-200-8098; CONF-9508104-; ON: DE95009230; TRN: 95:006736-0110
Resource Relation:
Conference: 2. meeting on biomass of the Americas, Portland, OR (United States), 21-24 Aug 1995; Other Information: PBD: [1995]; Related Information: Is Part Of Second biomass conference of the Americas: Energy, environment, agriculture, and industry. Proceedings; PB: 1741 p.
Country of Publication:
United States
Language:
English