Holmen endeavours to minimise its quantity of waste and to utilise the highest proportion possible. Waste taxes and landfilling costs necessitate cost-effective management. Waste is separated into categories at all the units. Employees and contractors receive regular training in waste-handling procedures.
As no production waste goes to landfill, the mill is not required to pay waste tax. All production waste (treatment plant gravel, precipitation sludge, green liquor sludge, ash and sludge from chemical flotation) is considered to have potential for use as a construction material in capping Holmen’s own landfill. As capping is a time-limited activity, several projects are in progress to find more long-term uses for the production waste. The recovery of precipitation chemicals, incineration with energy production and construction material for forest roads are just a few examples of how waste and by-products may be used.
Hallsta Paper Mill
The ash that arises in the burning of biofuels is largely used as construction material at Hallsta’s own landfill site, Ryadeponin. In 2012, the ash was used in landscaping Ryadeponin before it is finally capped. The ash is used under the sealing layer. Of the sludge that arose in the mill’s waste treatment in 2012, around 12 per cent was used for soil products and the remainder for the extraction of energy at the mill.
In 2012, the sludge dewatering plant at Hallsta underwent a major upgrade. Three worn, open belt filter presses were replaced with two new closed belt presses, accompanied by new control and transport systems. The new plant is expected to come into full operation in the first quarter of 2013. This will create more efficient and safer operating and work environment conditions at the plant. The main environmental improvement resulting from the investment is that it will be possible for the sludge, which has a high proportion of biosludge and is often difficult to dewater, to be dewatered to a higher dry content. This means that Hallsta will be able to achieve an estimated 30 per cent more energy from the sludge compared with before the investment, since it will now be possible to burn all the resulting sludge.
Braviken Paper Mill
Recovered paper sludge from Braviken Paper Mill is used to cap an external landfill site. New dewatering equipment for combustible rejects from the recovered paper process has resulted in better energy values for the waste and much fewer tonnes of waste being transported to the external waste-fired boiler. The quantity of combustible rejects has also fallen thanks to better sorting of recovered paper.
Holmen Paper Madrid
There was less deinking sludge in 2012 than in 2011 due to lower production. The sludge is principally used at present for agricultural purposes and for producing bricks.
The quantity of plastic rejects remains at the same level as in 2011.12 per cent of this type of waste was incinerated in 2012. Various projects ran in 2012 aimed at finding new uses for the waste.
The by-products/waste that arise in production can be classified into four categories:
Combustible by-products that are used
Mainly used to generate thermal energy at the mills or in external heating plants.
Waste for various uses
Several projects have been carried out in recent years to find alternative uses for the waste that is produced. Some types of waste, for example sludge from wastewater treatment plants, can be used as a soil improver after treatment. Incinerator ash has been used as a road-building material and soil improver, and to cap landfills.
Waste sent to landfill
As a result of legislation and efforts to find alternative uses, the volume of waste sent to landfill has fallen to the point where in 2012 it accounted for less than 1 per cent of the waste generated by Holmen’s operations.
Hazardous waste consists of materials such as waste oils, chemical residues and fluorescent tubes. Hazardous waste is dealt with by an authorised collection and recovery contractor. Certain fractions of the waste are recovered. Other fractions are destroyed under controlled conditions.