C&D Wood Fuel Quality

Boralex Inc., a Canadian owned and operated firm whose focus is electrical generation, is also an affiliate of Cascades Inc. Having its headquarters in Kingsey Falls, Quebec, and a business office in Montreal, Boralex Inc. is the largest producer of electrical energy from wood residues in North America.

Boralex’s mission is to pursue growth in the energy market in the Northeast United States, Canada and Europe. We consider ourselves a leader in the field of developing renewable power. We produce either thermal or electrical energy through different combustibles, such as wood or natural gas, and also through hydro plants.

Our company strengths are management, acquisition operation, maintenance and optimization of the plant production and economics. It has long been Boralex’s goal to recycle wood. In fact, it is the same philosophy adopted by Cascades Inc., which started to recycle its paper waste in the mid 1960s.

With eight power stations having an installed capacity of 29 MW located in Quebec, the United States and France, Boralex offers proven expertise in hydroelectric energy production. Boralex also owns two natural gas plants. One 31 Mw plant located in Kingsey Falls (Quebec) was built in 1989. It was the first cogeneration plant fueled by natural gas in Quebec, and still is the only one. The second one is in Blendescques, France. It is a 14 Mw natural gas cogeneration plant that was built in 2001.

But the majority of Boralex’s power comes from wood-powered plants. Boralex is the largest producer of electrical energy fueled by wood residue. The company owns and operates seven wood residue thermal plants, ranging from 16 to 50 Mw, for a total of 232 Mw of installed capacity. An eighth plant is in the start-up phase. This one will add 34.6 Mw bringing the total installed capacity for wood residue plants to 266.6 Mw.

Those plants are located as follows:

• Five are in Maine (Stratton, Athens, Livermore Falls, Fort Fairfield and Ashland);

• One is at Chateaugay, in New York state;

• another is in Quebec, at Dolbeau;

• and the new one in the start-up phase also is in Quebec, at Senneterre.

Supplying outsourced power is another strength of Boralex. In 1989, Boralex did its first such move, building a gas cogeneration plant and supplying steam to three paper mills. In 1999, Boralex bought the Dolbeau wood residue cogeneration plant from Alliance Forest Products, now owned by Bowater Forest Products of Canada, and is selling steam to its paper mill.

The energy business has changed in recent years. The newly deregulated energy has forced the biomass energy producers to optimize their plants, because the plants are selling their power at a much lower price than when they had contracts.

Boralex favors the employment of alternative fuels including Construction and Demolition Wood Debris (CDWD) in our fuel mix. In addition to being a cost effective fuel source, significant environmental benefits are realized from the use of CDWD in a controlled combustion process, including minimization of generated air pollutants when compared to a typical open burning process maximizing this material’s energy potential and conserving valuable landfill space.

In 1998 we started to look at burning alternative fuels in our boilers. The plants had originally been designed to burn sawmill residue such as bark and sawdust, and wood chips. Then we began testing the combustion of paper mill sludge, recycled wood, construction wood, railroad ties and recycled asphalt shingles.

Presently, the total consumption of all eight plants is around three million tons of wood residues. Our actual CDWD percentage is 10 percent for 300,000 tons. Three of our facilities are permitted to burn CDWD—Livermore Falls and Athens in Maine, Chateaugay in New York. This last is permitted to burn only clean recycled wood.

The Stratton facility located in Maine is expected to get its permit for CDWD in early 2002; all testing has been completed. The two other plants in Northern Maine - Fort Fairfield and Ashland - have also started the process to obtain the permits.

 WOOD QUALITY

The first criterion is size. Boralex prefers a three-inch minus chip that is very clean. Dirt, drywall, sand, metals, plastics etc. in the recycled CDWD do not burn. However, at high temperatures these contaminants adhere to the boiler tubes and create an insulator that over a short period of time destroys the boiler. Obviously, if the life of the boilers is shortened, then the plants are not a stable and reliable outlet for the CDWD. That is why the quality of the wood is so important.

A small amount of paint on the wood is not a big problem for us. We are required by the EPA to test the air emissions from the stacks. We have to fall within a certain range, which limits the amount of CDWD we can burn to 10 percent of infeed.

CDWD can also affect the ash we create. Every month we check ash composition. Ash from our plant is land spread. If we use a higher percentage of C&D wood in the mix, we have to put the ash in a landfill, which is more expensive. We would like landfills to take the ash back as alternative daily cover. Our ash, which is typically only three percent to four percent of the wood we consumed, is accepted as an alternative daily cover in Maine and Quebec. The recycling industry has to work with Boralex in order to make sure our ash is accepted and used.

That is another reason clean recycled C&D wood is important to Boralex. When we feed our boilers poor quality infeed material, we have as much 10 percent ash left over, rather than four percent. If more waste is coming out in the ash, that means it didn’t burn, but we paid for it, and we are paying again to dispose of the ash. It also overloads our system for handling ash, which again affects our profitability.

 Most treated wood, whether it is railroad ties or telephone poles, is a material we can accept. But chromated copper arsenate (CCA)-treated wood we cannot accept, because when that is burned it creates dioxin levels in our emissions and ash that are unacceptable.

Metals are another contamination problem. We have wood shredders at our plants as well, and everything goes through those before entering our boilers. Our shredders don’t like metal either. We have magnets, and we can take some of it out, but we prefer the supplier of the wood take the metals out.

Cardboard in the material can be burned, as long as not treated with wax. A small amount of paper contamination is not a problem, as long as it is only a very small percent.

Transporting recycled product fuel to our boilers is an issue we face every day. To get the product to our plant, we have certain levels we can pay, otherwise freight costs become prohibitive. Backhauling is the key to reducing those costs, and we try to work with our suppliers on these schedules. One solution we would like recyclers to work with us on is to take the ash back with them as backhaul.

We plan on being in this business for a long time, and having more than one plant taking the recycled material, we have a lot of flexibility and are able to guarantee we can take the wood year-round. Chances are very remote that all the plants would be down at the same time, and through contracts we are a steady outlet to the recyclers. But once again – quality is important.

The environmental benefits of using CDWD are also important, by reducing volume to the landfill, thus extending the life of these existing landfills. We need to work together with the recyclers, state and local regulatory officials on the viability of the recycling opportunity we present.