Canadian Consulting Engineer

2012 SCHREYER AWARD – Photocatalytic Gas Treatment

October 1, 2012
By exp

For a new wood panel manufacturing plant in Moncure, North Carolina, Uniboard Pfleiderer asked exp to come up with a new process to treat the gases produced by the plant’s pressing and drying operations.

For a new wood panel manufacturing plant in Moncure, North Carolina, Uniboard Pfleiderer asked exp to come up with a new process to treat the gases produced by the plant’s pressing and drying operations.

Traditional methods used in the industry to oxidize and destroy polluting volatile organic compounds (VOCs) were not viable options to the company, either due to space, operational and temperature considerations, or because they were too costly and harmful to the environment.

Exp was recommended to the German-based parent company because the Canadian firm had developed an innovative process for two Uniboard plants in Quebec to effectively oxidize a single polluting compound – formaldehyde – via catalysis using oxygenated water.

For the U.S. plant, exp needed to go further and develop a process that would destroy several different types of VOCs. The process also had to meet the State of North Carolina’s and the U.S. Environmental Protection Agency’s very stringent environmental standards. Many unsuccessful attempts had been made in the past, and no other technology had been invented in over 30 years to address this kind of issue.

Compact, cost-effective, non-polluting

For the North Carolina project, exp developed the groundbreaking Photocatalytic Gas Treatment (PGT) process that exceeded all expectations. PGT is effective, economical, compact and energy efficient, and it does not produce greenhouse gases. Exp’s experts in pure and applied science, working in the company’s own laboratories, steered the innovative PGT process through from concept to implementation.

The PGT technology is now patented or has patents pending in 39 countries. It is a global first in advanced oxidation, where hydrogen peroxide is used to generate the oxidizing agent via photocatalysis, on an industrial scale, to dynamically treat polluting gases. In addition, the use of ultraviolet lamps to regenerate the stabilized catalyst, combined with hydrogen peroxide, represents one of the most groundbreaking and economical ways to oxidize polluting, water-soluble, organic compounds such as alcohols, aldehydes, phenolic compounds, etc.

The EPA is carefully analyzing the new technology because it might replace thermal destruction technology that, simply put, is efficient but at the same time is expensive and uses combustion to produce heat.

This spring, exp was invited to Brussels to present PGT technology to the European Union’s committee for the recognition of new and innovative technology in environmental matters.

Advanced oxidation process

To meet all the criteria for the project, exp proposed the advanced oxidation technology using hydrogen peroxide. Exp developed the catalysts required for advanced oxidation, which in turn needed a source of energy to be reactivated. The method chosen to keep the catalysts active in the reaction water was energetic photons. Ultraviolet lamps were therefore used for photon production, although sourcing these lamps and calculating their power requirements proved to be difficult, since none had ever been manufactured for this type of large-scale industrial application.

In the presence of stabilized catalysts, the hydrogen peroxide generates an OH radical that reacts thoroughly with organic pollutants, reducing them to carbon gas. Extremely effective, this catalyzed reaction requires a very low concentration of hydrogen peroxide in the water to be efficient.

The catalysts developed by exp contain no noble or heavy metals and are biodegradable. As water is a precious natural resource, PGT was designed to operate in a quasi-closed loop so that 99.99% of the water is constantly reused.

Benefits to manufacturing and environment worldwide

The technology reduces the factory’s carbon emissions by more than 80,000 tons per year. Also, the technology provides a clean air environment inside the factory to ensure the health and safety of workers.

The project was delivered in a very aggressive timeframe. Research had to be completed in 16 weeks – from early August to late November 2008 – so that pilot testing could begin in early January 2009. Design engineering was initiated shortly after the beginning of the pilot tests to feed design details to the construction site. The engineering, the system’s on-site construction and the shop production of major parts were occurring almost simultaneously.

The two PGT units were officially tested in October 2011 to evaluate their performance in the destruction of methanol and formaldehyde. The results were conclusive – both installed systems would allow the client to meet the EPA’s and the State of North Carolina’s regulations.

Following the project’s success, interest in the technology in the U.S. has grown and over 22 licensing modification requests have been submitted to the EPA by hardboard factories wishing to use PGT technology (exp has Canadian patent: 2,527,450; U.S. patent: 7,304,187).

The technology will benefit manufacturing worldwide and promotes Canadian know-how and engineering to other countries.cce

Name of project: Photocatalytic

Gas Treatment (PGT) for Uniboard

Pfleiderer, North Carolina, U.S.

Award-winning firm (prime consultant): exp, Quebec City (Yves Charest,

Bernard Blier, Eng., Martin Beaulieu,

Stéphane Chabot, Eng., Réjean Paradis, Eng., Tony Denis, Eng.)

Owner/client: Uniboard Pfleiderer


The jurors were impressed with this submission as it showcases a Canadian technology exported on a global basis that not only produces financial returns for the industry, but also tangible environmental benefits to society. This is engineering at its best — the practical application of an existing scientific theory for the benefit of society.


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