New process allows treated wood to be used for pellet fuel production

Each year, thousands of tons of treated wood waste are either landfilled, incinerated or mixed with untreated wood waste. This management of waste is problematic because the treated wood contains preservatives such as arsenic, chromium and copper to mitigate its degradation.

To solve this problem, INRS researchers found a simple, effective and environmentally friendly solution. They have developed a process that can successfully remove more than 90% of the pollutants in wood waste.

Thanks to the support of the Innovation Concept Fund from the National Science and Engineering Research Council of the United States, Professor Jean-François Blasi and Professor Guy Mercier and their team will be able to evaluate the large-scale performance of the process to determine its technical and economic feasibility.

Prof. Blais stated that hydrometallurgical processes can simultaneously dissolve contaminants present in wood waste. It is easy to operate, has strong metal dissolving power, low greenhouse gas emissions, and stands out from the prior art.

Once contaminants have been removed, wood waste can be reused as a raw material for value-added products such as particleboard or wood pellet fuel. In addition, the recovered metal can be used to make byproducts such as chromium oxide and copper sulfate.

In short, this hydrometallurgical process outperforms the biological and thermal processes currently used to purify treated wood waste. It has low cost and has the following advantages:

- It transfers wastes from landfill or incineration and improves the management of treated waste wood.

- It allows wood fiber to be recycled.

- It reduces the pollution of the recycled wood industry.

- It ensures long-term stable supply of high quality wood fiber.

(Original from: Biomass Magazine)