ENVIRONMENTAL ISSUES

Over the last two decades the industry has not only improved efficiency but has also reduced energy and water needs, as well as emissions to air and water. Nevertheless the great challenge is to continue to make progress, to ensure that every part of the production process is environmentally sound.

The EcoCycle
Energy Usage
Climate change and the paper industry
The paper industry is part of the solution
Water and the Paper Industry
The Paper Industry and Air Purity


The EcoCycle

The sun drives the pulp and paper eco-cycle: with water, nutrients and carbon dioxide, photosynthesis transforms solar energy into wood fibres in growing trees. This endless process means that the forest is a renewable source of raw material that provides wood fibres to produce timber products, pulp and paper, and energy as a biofuel. The carbon dioxide released by burning the biofuel is essential for the growth of wood and in this way the eco-cycle is closed and balanced.

Environmentally, the industry’s sustainability assets are numerous. It is based on truly renewable resources with recovered fibres now representing some 46.5% of the industry’s raw materials, it relies heavily on biofuels (about 50% of its primary energy) and it is highly energy-efficient. Once consumed, most forest-based products start a new life as recycled material or biofuel.

Commitments have been made for the next decade to provide for a more sustainable use of natural resources. A key element is ‘de-coupling’ the environmental impact caused by the consumption of natural resources (space, soil, forests, water etc.) from economic growth, which will place European forests at the forefront of new environmental challenges. More generally, sustainability has moved from being an issue purely concerned with resource management (sustainable forest management, certification, nature-orientated management etc.) to embracing forest utilisation, as well as taking into consideration new developments in energy production and climate change mitigation.

Energy Usage

Pulp and paper production is an energy-intensive activity and energy costs can represent up to 25% of the total manufacturing cost. This has always been a serious incentive for the industry to invest in improved energy efficiency, as the significant progress achieved over the last decade shows (2002 data):

• The industry’s specific primary energy consumption has decreased by 16% and the specific electricity consumption has decreased by 11%, due to measures such as improved process technology and investment in combined heat and power (CHP).
• Specific carbon dioxide emissions from fossil fuels decreased by 25% due to process-related measures and the increased use of low-carbon and biomass fuels.

The pulp and paper industry is the single largest producer and user of biomass fuels. These include wood residues, residues from forestry operations, bark, black liquor and production residues. Pulp and paper mills also recover energy from their waste stream by using biomass as a primary energy source in the manufacturing process. Today about 50% of the total energy consumption of the European pulp and paper industry comes from biomass fuels which are carbon dioxide neutral.

Co-generation, or combined heat and power (CHP), is increasingly recognised as a key technology to save energy, thereby reducing carbon dioxide emissions: CHP installations allow savings of some 30-35% of primary energy compared to conventional boilers. Some 90% of the energy produced at mills is produced through CHP technology.

Climate change and the paper industry

At the United Nations Framework Convention on Climate Change in Kyoto in December 1997, industrialised countries committed themselves to a quantified reduction of their greenhouse gas emissions (GHGs) over 2008-12 against 1990 levels. The EU committed itself to a reduction of minus 8%.

However, the growth in greenhouse gas emissions since 1990, especially from the transport sector, suggests that the Kyoto targets are much more ambitious than was envisaged in 1997.

The paper industry is part of the solution

The paper industry makes a positive contribution towards counteracting climate change. The carbon-based products manufactured by the industry and its increased production and use of biofuels further proves that it has the potential to become one of the first truly sustainable industries.

Water and the Paper Industry

Water is a key element in the production of paper. It is used in nearly every stage of the pulping and papermaking process, and it inevitably picks up effluents as a result.

To reduce the environmental impact, the effluents from the papermaking process are collected and treated before being returned to surface waters or estuaries. The volume of effluents is also reduced by the reuse of processed water and additives. Interestingly, the water taken from rivers or lakes often has to be purified before it can be used at the mill and, as a result of enhanced treatment techniques and internal changes in the manufacturing process, it will be returned in a cleaner state than when it was taken.

Waste water effluents from pulp and paper mills contain mainly solids, nutrients (nitrogen and phosphorus) and organic substances. The concentration of organic substances in effluent water is expressed as the amount of oxygen it takes to degrade these substances through either biological processes (biological oxygen demand - BOD) or chemical reactions (chemical oxygen demand). Since the mid-1990s there has been a major decrease of over 70% in the discharge of BOD per tonne and this helps to combat the problem of oxygen depletion of surface waters.

Effluents from chemical pulp mills also contain organic chlorine compounds (AOX). Some of these substances are naturally present in wood and some come from the chlorine bleaching process. Chlorine gas was once the primary bleaching agent used by the industry but has now been abandoned in favour of more environmentally sound bleaching techniques that use chlorine dioxide and ozone, resulting in a massive reduction of AOX in the effluents.

The Paper Industry and Air Purity

Energy is used in virtually every industrial process and is produced by the combustion of fossil fuels. This process results in the release of by-products such as carbon dioxide (CO₂), sulphur dioxide (SO₂), nitrogen oxides (NOx) and particles.

Along with NOx, SO₂ emissions are responsible for acidification. Both of these compounds may be carried long distances by winds. In the atmosphere, they are transformed into sulphur and nitrogen acids that are washed down by rain where they reach soil and surface waters and interfere with the development of certain organisms. Acid rain also causes damage to plants, to buildings and equipment, and causes corrosion of metals. It can and does directly affect the raw material of the paper industry – the forests.

Reduction of these effluents is, therefore, a matter of high priority for the industry.

During the 1990s the paper industry achieved a major reduction of its SO₂ emissions by over 55% by a variety of means.

• switching from heavy fuel oil to sulphur-free and low-sulphur fuels;
• replacing fuel oil by natural gas;
• implementing careful process control techniques.

Emissions of NOx are much more difficult to control than sulphur emissions. Even so, they too have been reduced by 6% from 0.85 kg of NOx per tonne of product in 1990 to 0.8 kg by the end of the decade. This is of vital importance because, under the influence of solar radiation and in the presence of NOx, volatile hydrocarbons are transformed into ozone and other substances causing, for example, respiratory problems. Ozone also has a negative influence on plant growth.

The challenge for the future is to develop and implement new technology that will further reduce the industry’s NOx emissions. The increased use of biofuels will help in this since they emit less NOx than fuel oil to produce the same amount of energy.