Reducing our environmental footprint

Michel Lemieux, Technical Services Manager, Windsor Mill

In 2011 and 2012, four projects totalling investments of $30.3 million were made in Windsor as part of the Government of Canada’s Pulp and Paper Green Transformation Program. The objective: to improve the mill’s environmental and energy performance. These projects have reduced greenhouse gas (GHG) emissions, water consumption and natural gas use, and increased Windsor’s production of electricity and steam. The following is an overview of these projects:

Capacity increase at the biomass boiler: $13.7 million

The biomass boiler that uses bark and biosolids from the mill was modified to increase its steam production capacity by 15%, from 134 to 160 metric tons (147.5 to 176 tons). The boiler feed was also optimized to be able to burn a controlled amount of construction/demolition waste or tire derived fuel (TDF), should the need arise. This project allows for a potential reduction in natural gas consumption of 17 million m3, equivalent to 7% of the mill’s GHGs, while extending the useful life of our landfill site.

Reduction in steam consumption at the paper machines: $11.1 million

A steam-box was installed on each paper machine in the press section. This has resulted in an increase in sheet dryness, better control over the humidity profile and a reduction in steam consumption in the dryer section. New thin stock screens with slotted baskets were also installed on each paper machine, allowing the removal of more contaminants, and enabling a higher proportion of recycled fiber (between 30%-50%) to be used in some of our products. This project will enable us to reduce our emissions by 1,680 t CO2e annually.

Increased electricity production through cogeneration: $1.3 million

Two steam turbines were replaced with electric motors to redirect the steam generated to energy production. The result: 1.6 MW more power produced from renewable energy. That’s the equivalent of 16,000 100W light bulbs.

Reduction in water and energy consumption at the pulp mill: $4.2 million

We installed high performance mist eliminators in effects 1 to 4 of the evaporator train to produce a cleaner condensate that can be reused by brown-stock washer showers. The excess condensate is reused elsewhere in the mill, allowing for a reduction in warm water use and a decrease in the consumption of water and effluent of nearly 1.9 million m3, while decreasing the quantity of steam needed to heat water for the showers.

Numbers that speak volumes

Thanks to these projects, the Windsor Mill expects to reduce its GHG emissions by 10%, or the equivalent of having 2,350 cars off the road. It also expects to reduce its water consumption and effluent production by 1.9 million m3, or 7% of its total water use. Natural gas consumption will decrease by nearly 17 million m3. Biomass consumption should fall by 30,000 metric tons (33,000 tons) annually and the cogeneration plant will produce 1.6 MW more electricity. These are environmentally beneficial investments that will have a positive impact on our communities and for generations to come.

Finally, it is important to note that these projects were completed without any recordable injury, on schedule and on budget. This is a great achievement for the Windsor team.