* Mandatory fields
This information is required to send the newsletter.
In the production of our corrugated cardboard, we depend on the long-term availability of paper, water and energy. Our production processes are therefore aligned to protect these strategic resources whilst minimising our ecological footprint. We reduce our consumption through efficient water and energy management in our plants.
At Oudegem, the largest paper mill in the group, energy needs have always been the focus of interest. Today, the plant is nearly self-sufficient in its energy supply; continuous innovation ensures ever higher energy efficiency. The plant has three co-generation installations, which combine heat and electricity generation in an optimal way. One of these is fuelled by biogas.
The biogas is generated onsite as a by-product of water treatment. In this context, starch and paper fibres play a dominant role. Starch is an additive in the process of paper production, used to increase the strength of the paper and water resistance. In addition to this, it is applied in the corrugation process to glue together the different layers of paper or the finished boxes. When old paper is recycled, the starch dissolves in the process water, together with the paper fibres. The paper fibres are separated and recycled to produce new paper, whilst the residue containing the starch is sent to the water treatment plant. Apart from the starch, process water generally also contains (small) paper fibres which are unsuitable for paper recycling and other organic compounds. This biological waste is digested anaerobically in dedicated reactors for water treatment, thus generating biogas.
Since 2005, biogas has been used to fuel the co-generation installations. However, production volumes have increased over the years, leading to higher biogas generation. Since the paper mill engine was already running at 100% capacity, the surplus biogas was used to power the conventional high-pressure boiler instead. With more efficient engines available on the market, VPK now has the option of replacing the first engine and powering the new one with biogas. In this case, increasing production volumes would actually lead to the generation of more biogas as a renewable source of energy – a great example of a successful combination of economy and ecology. “Capturing and using biogas is indeed a sound choice, increasing energy efficiency and decreasing expense,” says Johan Dhaese, group coordinator for energy and environment at VPK. “And since biogas is a renewable source of energy, we also reduce CO2 emissions.”
Water treatment system Oudegem – benefits:
Being located next to the river Dender, the paper mill at Oudegem was always able to rely on an abundant supply of fresh water. However, this supply met with high demand: As the Dender runs through a heavily industrialised area of Belgium with a lot of agglomerations in the vicinity, this has put a certain degree of stress on the river. Due to tremendous and continuous efforts of the local communities and industry, water quality has improved significantly over the past couple of years and aquatic life in the river has started to flourish again. To support this trend, VPK is now striving to recycle as much water as possible, and to purify water before discharging it in a completely safe quality.
But VPK is not stopping there. For some applications at Oudegem, water from underground or municipal sources was needed, offering a higher quality. To avoid any negative impact on these two precious sources of water and to generate high-quality water for its plant, VPK decided to build a state-of-the-art water treatment system to purify water from the river.
This is done in a first phase by removing suspended solids from the water with the help of a coagulant in a flocculation tank. Afterwards, the water is purified using a sand filter, which reduces the suspended solids by up to 95%. The second phase consists of a pressure-driven ultrafiltra- tion membrane which works as a very fine filter, blocking material as small as 0.1 µm in size. As a result, the water doesn’t undergo chemical treatment and bacteria and viruses can also be removed.
The new water treatment system allows VPK to stop consuming groundwater altogether and to reduce consumption of municipal water to a minimum. Furthermore, VPK contributes to the reduction of desiccation of the area, and water resources for flora and fauna are preserved in the best possible way.