Oil Borne Preservative Removal By Torrefaction

A decontaminated wood product, prepared by a process comprising the steps of:

• placing a contaminated wood product in a treatment vessel, the wood product including an initial amount of an absorbed contaminant selected from the group consisting of creosote, a mixture of pentachlorophenol and an carrier oil, a mixture of copper naphthenate and a carrier oil, and combinations thereof;
• heating the wood product to a treatment temperature sufficient to evaporate at least a portion of the absorbed contaminant from the wood product but insufficient to pyrolyze the wood product;
• and
• maintaining the wood product at the treatment temperature for a period of time sufficient to reduce the absorbed contaminant in the wood product to a final amount which is less than about 20% of the initial amount, and thereby provide a decontaminated wood product.

A method for recycling wood preservatives, comprising the steps of:

• placing a contaminated wood product in a treatment vessel, the wood product including an initial amount of an absorbed contaminant selected from the group consisting of creosote, a mixture of pentachlorophenol and an carrier oil, a mixture of copper naphthenate and a carrier oil, and combinations thereof;
• heating the wood product to a treatment temperature sufficient to evaporate at least a portion of the absorbed contaminant from the wood product but insufficient to pyrolyze the wood product;
• maintaining the wood product at the treatment temperature for a period of time sufficient to reduce the absorbed contaminant in the wood product to a final amount which is less than about 20% of the initial amount;
• recovering at least a portion of the evaporated preservative;
• and
• treating a second wood product by applying a composition to the second wood product which comprises at least a portion of the recovered preservative.

A method for removing contaminants and other materials from a wood product, comprising the steps of:

• providing a contaminated wood product, the wood product including an initial amount of an absorbed contaminant selected from the group consisting of creosote, a mixture of pentachlorophenol and a carrier oil, a mixture of copper naphthenate and a carrier oil, and combinations thereof;
• heating the wood product to a temperature from 60° C. to about 120° C. for a period of time sufficient to reduce the amount of moisture in the wood product to less than about 10%,
• heating the wood product to a temperature from 240° C. to about 280° C. for a period of time sufficient to thermally de-sorb the absorbed contaminant in the wood product to a final amount which is less than about 20% of the initial amount;
• recovering cellulosic by-products from the wood product by heating the wood product to a temperature from about 280° C. to about 365° C. for a period of time sufficient to reduce the cellulosic by-products in the wood product by at least 50%;
• recovering phenolic derivatives from the wood product by heating the wood product to a temperature from about 365° C. to about 450° C. for a period of time sufficient to reduce the phenolic derivatives in the wood product by at least 50%.