Pulp, paper, power and the planet

The price of power is global warming and acidification. Reducing these effects is a daunting task for the industry

by Leslie Webb

The paper industry accounts for an estimated 4.0% of global energy consumption, but only around 1.2% of fossil fuel-derived carbon dioxide emissions due to its extensive use of wood for energy generation. The most important adverse effects of energy consumption are attributable to the use of fossil fuels, not just their unsustainability, but also the emissions from burning them - carbon dioxide in terms of global warming and sulfur dioxide and nitrogen oxides (NOx) in terms of acidification.

Our understanding of climate change is largely due to the work of the Intergovernmental Panel on Climate Change (IPCC), which was set up by the World Meteorological Office and the United Nations (UN) Environment Program in 1988. The panel's third report was published at the beginning of this year and provides the strongest evidence so far that the global warming of the last 50 years is due largely to human activity. Any increase in surface temperatures may be due to natural factors, such as variations in solar irradiation and volcanic activity, but the available evidence points to human factors, for example, the increase in emissions of greenhouse gases, being the most significant. The biggest single contributor is fossil fuel combustion. This has increased the carbon dioxide concentration to about 370 ppmv (parts per million by volume) compared with a stable 280 ppmv over the hundreds of years leading up to the start of the industrial revolution in the middle of the 19th century.

Figure 1: Energy and Environment

The worst-case scenario, with continued high reliance on fossil fuels, predicts carbon dioxide levels approaching 1,000 ppmv by 2100, but a figure of around 550 ppmv is considered by many to be a reasonable target.

Rio to Kyoto

The main practical driving force for limiting emissions of carbon dioxide is the Kyoto Protocol, which has its origins in the UN Conference on Environment and Development (the Earth Summit) held in Brazil in 1992. The conference created five new instruments to further the attainment of sustainable development, one of which was the Framework Convention on Climate Change, since ratified by about 180 countries. Yet the convention contained little in the way of real targets except that developed countries should aim to return emissions of greenhouse gases to 1990 levels by 2000. The impasse about post-2000 targets for the reduction of greenhouse gas emissions was broken at the 1995 Berlin meeting by a suggestion from European Union (EU) countries that the issue should be addressed in a protocol to the convention. As a result, the Kyoto Protocol was finally pieced together in late-1997.

But several of the detailed practical points, particularly about the definition of allowable carbon sinks and the so-called flexible mechanisms, were not precisely defined at Kyoto, and left for later resolution. So it was no great surprise when the meeting in The Hague in late-2000, which was supposed to be a rubber-stamping of these important details, broke up with no agreement. A supposedly final attempt at resolving these issues in Bonn in July 2001 achieved some sort of compromise agreement, although it did not finalize all the points of detail, which are supposed to be thrashed out at a "final" meeting in Morocco in October. One of the stumbling blocks at The Hague had been over the use of carbon sinks. The Bonn agreement means that around 100 million tonnes/yr of carbon dioxide carbon (70% of the savings due to be achieved under the protocol) can be secured through this route.

Not surprisingly, only some 34 countries had ratified the protocol by mid-2001 and it requires adoption by at least 55 regions. The decision of the US to withdraw from the process earlier this year, claiming it to be "fatally-flawed" is unlikely to change with the compromises delivered at Bonn. But more pertinent to the US decision was probably the fact that its emissions of fossil fuel carbon dioxide had increased by 12% in 1990-1999. The nation's original Kyoto obligation was a 7.0% reduction by 2010 - a daunting challenge, albeit one that would probably have been helped by the current downturn in the US economy.

One of the factors that will drive improvements on the energy front over the next few years within EU countries is the directive on integrated pollution prevention and control (IPPC). In many cases, this will be the first time that energy use (rather than just the emissions resulting from its production) is regulated by legislation. The actual wording in the directive simply requires that "energy is used efficiently" through the application of best available techniques (BAT). But it is left to individual countries to interpret the meaning.

Pulp and paper options

Pulp mills can try out a number of solutions to improve energy usage, for example, debarking, extended modified cooking and oxygen delignification, increased concentration of black liquor before burning, collection and incineration of odorous gas emissions, recovery of steam from mechanical pulping and energy recovery from incineration of wood-derived wastes.

Options for paper mills involve minimizing water use, optimization of sheet dewatering in the press section of the paper machine and energy savings through use of energy-efficient technologies. Other solutions involve anaerobic bio-treatment of wastewaters from recycled mills, use of combined heat and power (CHP) and energy recovery from incineration of rejects and sludge from recycled mills.

The only country that has so far formally implemented the directive is the UK, where there is a specific guidance note for pulp and paper mills and a general guidance note for energy efficiency. Bark or sludge is the preferred fuel, but as there is little wood pulping in the UK, sludge is the most widely available waste. Two of the three UK mills with mechanical pulping plants recover energy from bark combustion, but there is only one operational combustor for sludge (at Aylesford Newsprint) with a second being built at the nearby Kemsley site serving one St Regis and two M-real mills.

Where a waste-derived fuel is not a practical option, the guidance note, not surprisingly, says that natural gas is the next best fuel from an environmental perspective. Use of techniques other than these have to be justified, as does any energy setup other than CHP.

Industry responses

The use of fossil fuels for energy generation in the manufacture and transportation of paper products is the pulp and paper industry's main contribution to climate change. At the same time, the industry is part of the cluster of forest-related industries and has a major role to play in maximizing the uptake of carbon in new or replanted forests. The industry's re-use of old paper products also contributes to minimizing emissions of methane from landfills which, although a much shorter-lived atmospheric gas than carbon dioxide, has a greater global warming potential.

So the paper industry is faced with the challenge of improving the environmental profile of its generation and use of energy, while remaining competitive against alternatives such as plastics for packaging. An improved energy profile for any industry can be achieved by shifting energy management in a number of directions. These include maximizing the use of all renewable forms of energy, whether this comes from the mill's own forestry operations, from pulping/papermaking wastes or from non-recyclable used papers. Then there is the switch to CHP wherever possible to maximize the energy yield from every scrap of primary energy, whatever its source, and a move away from fossil fuels with a high carbon intensity per unit of energy, such as coal, to those with a lower carbon intensity (natural gas or hydrogen).

Different reporting units make comparison of energy statistics difficult, although data has recently been accumulated on a larger scale than before. An example is the document assembled jointly by the American Forest and Paper Association, the Canadian Pulp and Paper Association, the Confederation of European Paper Industries (CEPI), the Japan Paper Association and the New Zealand Forest Industries Council for the Kyoto Protocol meeting in The Hague last year. This is a powerful combination as these countries account for about 70% of global paper production. The report indicates that, although the specific carbon dioxide emissions have declined (from -5.0% in Japan to -30% in New Zealand) from 1990-1997, the absolute carbon dioxide emissions have generally increased by +5.0% to +10%. The exception is New Zealand, which, despite a 13% increase in production, has managed to reduce its absolute carbon dioxide emissions, albeit only by a couple of percentage points.

Another factor that does not help comparisons is the continuing consolidation among paper companies, which means the manufacturing base is rarely the same from one year to the next. International Paper (IP) does not divulge much about energy efficiency in its 2000 environmental report, but the company says that about 60% of total energy generated internally at its US mills comes from renewable sources. It is surprising to see also that IP's first CHP plant only started up in January 2000, although two more are under construction. In 2000, Stora Enso obtained 30% of its electrical energy from CHP plants and 64% of the group's on-site fuel consumption from renewable sources (wood).

In 1997-2000, UPK-Kymmene managed to reduce its actual carbon dioxide emissions by about 5.0% while increasing paper production by about the same. A major contribution to the achievement is the increased use of renewable energy sources, notably wood. In just one year, the company doubled the amount of energy obtained from logging residues. The trend looks set to continue as UPM-Kymmene is constructing several biomass-powered energy plants, including what will be the world's largest facility (Alhomes Kraft) at Pietarsaari in Finland.

Transport factor

Sources say that transport accounted for around 27% of global energy consumption in 1997 and the proportion is increasing steadily. In developed regions such as the EU, the share is even higher (31% in 1998) and is the single largest factor behind the increased energy demand in recent years. The biggest energy-user and carbon dioxide emitter within the sector is road transport. Not surprisingly, energy consumption (and related emissions) from logistics operations is one area where some pulp and paper companies have devoted a lot of time and effort in the last few years. This is probably best exemplified by the three large Scandinavian-based, but global-thinking, paper companies - M-real, Stora Enso and UPM-Kymmene, all of which devote sections in their corporate environmental reports specifically to transport. By contrast, the reports from some of the larger North American companies (IP, Procter & Gamble) say nothing about transport.

Comparison of transport-related energy use between companies is hindered by differences in reporting protocols, but the most common reporting unit is tonnage transported x distance (for example, tonne.kilometres or t.km). UPM-Kymmene and M-real gave values of 33 Gt.km and 18 Gt.km respectively for product transport in 2000. Inclusion of transport for the main raw materials used by M-real bumps up the total to around 25 Gt.km, an increase of some 35%. The SCA group bundles raw materials and products together to give a total of 20 Gt.km, but it also reports a figure for energy use in transport, which corresponds to about 15% of total energy use within the group.

The emission side of transportation has been studied in some detail in research conducted by the Finnish Pulp and Paper Research Institute (KCL) using life cycle assessment (LCA) techniques. In one scenario, the total emissions from producing lightweight coated (LWC) paper in five European countries for a customer in Hamburg was estimated. For carbon dioxide emissions, transportation accounted for 4.0% of the total in Germany (small product transport distance, but high total emissions) to 13% of the total in France (high contribution of nuclear power to external energy and hence low total emissions). The calculated sulfur dioxide emissions, this time for a customer in London, are not as high as across the range quoted above, being no more than 20% of the total sulfur dioxide emissions. However, emissions of NOx from transport of LWC paper are consistently high at 40-50% of the total.

Given these very significant contributions by transport to overall energy consumption and related emissions, it is not surprising that papermakers are trying to reduce these environmental burdens. Over the last four years or so, Stora Enso has developed a system called Transport Chain Assessment, which includes various tools such as Profile to calculate emissions to make improvements. A new transport system called Base-Port was introduced last year (PPI September, 2001, pp 45-49). The concept includes a train-ship system connecting Sweden and the continent using large containers. Before startup, the company expected that the new system could halve energy consumption and emissions/tonne of paper moved. Early results are promising a 90% reduction in NOx emissions through use of catalytic converters on ships and use of low (<1.0%) sulfur fuel reducing sulfur dioxide emissions by 75% compared with standard fuel oil.

There are many similar examples from other paper companies, but even with less movement of goods, the real challenges are still to come in terms of alternative energy sources to fossil fuels.

Cleaning up the future

In addition to the requirements and mechanisms within the Kyoto Protocol, a number of countries have introduced fiscal incentives to reduce either energy use and/or energy-related emissions. Taxation of energy use is imposed in several countries such as Sweden, Germany and the UK, but it appears to have fallen out of favor as an EU-wide measure.

What does appear to be likely at an EU level is the use of voluntary agreements between sectors and governments. In return for government agreement not to impose energy-related standards, the industries are faced with the challenge of becoming world leaders in energy efficiency by 2012 through benchmarking their performance against best practice in other countries.

Another favored measure is trading in emissions. It has been calculated that trading could reduce the EU's costs of compliance with the Kyoto Protocol by 20-40% depending on whether the solution includes just energy generators or all sectors. Although the Kyoto Protocol has some problems, the subject of climate change is just one of several issues that were placed on the sustainability agenda by the Rio Earth Summit nine years ago. The progress on the wider front will increasingly come under scrutiny as we approach the Rio+10 conference in Johannesburg, September 2002.