Technical Publications 

EKONO's personnel are very active in technical associations and regularly present papers on the results of recent studies.  The following abstracts summarize some of the recent publications that are available from EKONO.  To request a copy of a publication, please e-mail us, providing us the name of the requested article and information where to send it (mail or fax).

Links to abstracts on this page:

Will Your Competitiveness Suffer from Increased Energy Prices?
Effluent Manganese Limit Poses a Special Problem for a Bleached Kraft Pulp Mill on a Small River
Optimum Energy Efficiency - Comparison between North American and Nordic Pulp and Paper Mills
Costs for Reducing Greenhouse Gas Emissions from the U.S. Forest Products Industry
The Impact of the Kyoto Agreement on Forest Industry in Canada
Air and Effluent Quality Improvements Through Condensate Stripping
Feasibility of EPA's Advanced Technology Tiers
Why Energy Conservation?
Current Environmental Performance of the Pulp and Paper Industry
Who Can Afford to Save Water?
Technical and Economic Feasibility of a Low Effluent Bleached Kraft Mill
How Green is the Future for Pulp and Paper?
Who Could be Eco-Labelled:  An International Comparison of the Pulp and Paper Industry's Environmental Performance

"Will Your Competitiveness Suffer from Increased Energy Prices?", H. Mannisto, Advanced Tech Symposium '99, Montreal, PQ, Canada, November 29, 1999.

Canadian pulp and paper mills consume as an average 30-50% more energy per ton of product than Finnish mills.  Many factors, such as age and size of the mills, price of fuels and electricity, product mix and grade structure, etc., have led to this situation.  With the increasing pressures for reduction of emissions and for sustainable operations, the fuel and power price differences between the countries are likely to level out.  This may cause high energy users to suffer loss of competitiveness and search for ways to cut back the energy consumption and cost.

"Effluent Manganese Limit Poses a Special Problem for a Bleached Kraft Pulp Mill on a Small River," E. Mannisto, G. Bourree, and G. Wohlgemuth, TAPPI 1999 Pulping Conference, Orlando, Florida, November 1999.

The Weyerhaeuser Company, Grande Prairie is likely so far the only mill to have an effluent discharge mass limit for manganese (Mn).  The manganese limit relates to the strict surface water quality criteria in Alberta and to the low flow of the receiving river.  After river modeling Alberta Environment set the current limit as 65 kg/d of soluble Mn decrasing to 45 kg/d in 2002.  To meet the future limit the mill needs to lower the discharge by around 36%.  Extensive monitoring of manganese has been carried out during several years to understand the sources of Mn into various effluent streams, the behavior in the process and effluent treatment as well as the variability of manganese.  The monitoring graphs are documented, together with an analysis of the influent variability and reasons thereof.  Manganese in the ASB is fluctuating between soluble and particulate form in a way that is currently not understood.

The paper shows detailed manganese balances for the process and effluent treatment based on monitoring data.  Essentially all manganese enters the mill with the wood to the digester or waste wood to power boiler.  The main sources of manganese to the effluent are the acid bleach plant effluent (originating from unbleached pulp, manganese is washed out in bleaching and exits with bleach plant effluent), power boiler ash sluicing filtrates, and lime cycle losses.  Viable options to reduce the soluble manganese limit in the final effluent are documented, including:

• Reduction of influent and effluent variability
• Conversion to a dry power boiler ash handling system
• Use of an alternative source for lime to water softening
• Retainment of a larger portion of manganese in the recovery cycle for discharge with dregs (acidifying the pulp wash water, treatment of pulp with chelating agents, etc)
• Use of other treatment processes

To meet license requirements, the mill also has to reduce the color of their effluent, and oxygen delignification is being planned as a color reduction measure.  This may offer an opportunity for manganese reduction as well.

"Optimum Energy Efficiency - Comparison between North American and Nordic Pulp and Paper Mills," H. Mannisto and E. Mannisto, The Second Biennial Johan Gullichsen Colloquium, Espoo, Finland, September 1999.

Energy efficiency of the pulp and paper industry has lately become of keen interest.  The present market situation for pulp and paper products forces the industry to look for all possible and feasible cost savings opportunities.  Energy may not be the biggest cost item in the mills.  However, the savings in energy do not typically affect the production capabilities and product quality.  The recent international agreements and efforts to reduce the emissions to the atmosphere are best met by reducing the use of fossil fuels.  In addition to the cost and regulatory type of pressures some marketing issues, such as voluntary environmental labeling schemes, take the energy use into account.

The concern of continuous availability of fossil fuels and the tightening environmental regulations, with increasing energy taxes and prices as a consequence, have resulted in significant resources being invested in energy research targeting more efficient energy processes and energy conversion technologies.  More efficient energy systems are definitely needed in the long term.  However, especially in North America where most of the mills were designed when the cost of oil was less than 3 dollars per barrel, the energy efficiency improvements are not prevented by the availability of technologies but rather controlled by economic factors, i.e., capital cost and return on investment.  In Nordic countries where basically all mills were built or modernized for high energy prices the energy efficiency improvements are less obvious and more costly.

Data from public sources and from EKONO's files indicate that the energy consumption in the North American mills is significantly higher than in the Nordic mills.  This may not, however, mean that the energy conservation opportunities are easier to justify in the North American mills.  Low unit prices of energy because of, e.g., lower taxes together with a requirement of high ROI on energy as well as other cost reduction projects result in an optimum energy efficiency level much higher than that for the Nordic mills.

"Costs for Reducing Greenhouse Gas Emissions from the U.S. Forest Products Industry," B. Upton, R. Miner, and H. Mannisto, The Second Biennial Johan Gullichsen Colloquium, Espoo, Finland, September 1999.

This study was undertaken to estimate the costs for reducing CO₂ emissions from the U.S. forest products industry to levels 7% below estimated 1990 emissions, a target for the U.S. contained in the Kyoto Protocol. The pulp and paper sector of the industry has been studied by developing quasi-mill-specific energy balances for 90 mills accounting for approximately one-third of the pulp and paper produced in the U.S. Wood products facilities were handled differently due to limited data. One model facility was prepared for each type of wood product under study. Each facility's production was assumed to grow at 1.5% per year (an important assumption since costs have been found to be highly sensitive to growth rate). At this growth rate, and factoring in (a) continued improvements in energy efficiency and (b) the impacts of new environmental requirements, a 31% reduction from projected 2010 business-as-usual emissions would be needed to meet the Kyoto Protocol target.

Estimated annualized and marginal costs for CO₂ reduction are very sensitive to assumptions about power costs, fuel costs, and the profitability of selling mill-generated power to the grid.  If it is assumed that the industry will find relatively few opportunities for selling excess power for a reasonable profit, or that such sales will be discouraged because of doubts about the ownership of the credits for displaced power or by other disincentives, then a reasonable estimate of the annualized and marginal costs can be obtained by eliminating gas turbine combined cycle systems (GTCC) from the analysis. Under these conditions, annualized costs in 2010 are estimated to be approximately $1 billion/year while the marginal cost (at the point where the industry meets the target) is $177/metric ton carbon. In 2020, these increase to approximately $2 billion/year and $205/metric ton carbon respectively.

If, on the other hand, it is assumed that (a) the obstacles to using gas turbine combined cycle systems (GTCC) will be minimal, (b) power and fuel prices will remain constant (or change in a direction favorable to GTCC), and (c) there will be numerous opportunities for selling excess power at a sale price of 50% or more of the current purchase price, the annualized and marginal costs are much lower. Under these conditions, annualized compliance costs in both 2010 and 2020 are approximately -$250 million/year. Marginal costs for reducing emissions are $25/metric ton carbon in 2010, increasing to $35/metric ton in 2020.

"The Impact of the Kyoto Agreement on Forest Industry in Canada," E. Mannisto and H. Mannisto, CPPA Annual Meeting and Exfor, Montreal, PQ, Canada, January 29, 1999.

The Kyoto Agreement, which Canada among other countries has signed, commits most of the participating countries to reduce the emission of so-called greenhouse gases (GHG's) by 2010 to the 1990 level minus 6-8%.  For Canada the target for 2010 is set at the 1990 level minus 6%.  In this presentation it is assumed that any emitter of greenhouse gases has to implement necessary measures to reduce the emissions to the level as required by the Kyoto agreement.

Because of production increase and other increased activities, the projected GHG emissions from the Canadian pulp and paper industry by 2010 are much higher than required by the Kyoto Agreement.  Pulp and paper mills in Canada have already implemented a significant number of conservation projects and have voluntarily committed to further conservation measures, by promising to reduce the energy usage by 1% annually between 1995 and 2000.  As a result of these efforts and commitments, the projected CO₂ emission level in 2010 exceeds only by about 12% the level that is required by the Kyoto Agreement, while the same percentage figure is much higher in many other countries.  This is based on statistics published in the Canada Energy Outlook, which projects the energy usage in 2010 for the Canadian pulp and paper industry.  These projections already assume a significant increase in biofuel utilization in the Canadian pulp and paper mills by 2010.

The required reduction in the CO₂ emissions for the Canadian pulp and paper industry from the projected 2010 level is estimated to be about 2.9 Mt CO2/a.  This corresponds to 40-50 PJ/a reductions in the fossil fuel use in the pulp and paper industry, or about 1.2-1.4 GJ/t of product of fossil fuel reduction.  Based on benchmarking of the Canadian industry against the Nordic pulp and paper mills there is a significant potential for fossil fuel reduction, e.g., through energy conservation and increased back-pressure power generation.  Installation of gas turbines and implementation of new, emerging technologies are also possible.  The energy conservation approach is likely to be the most profitable option, however, especially for older mills.

"Air and Effluent Quality Improvements Through Condensate Stripping," D. Taflin, B. Krzysik, and P. Winter, TAPPI 1997 Pulping Conference, San Francisco, CA, October, 1997.

The Weyerhaeuser mill in Grande Prairie, Alberta was faced with increasingly stringent effluent BOD₅ requirements in the early 1990s. In addition, they were experiencing difficulties with effluent toxicity and community odor complaints. Condensate stripping was investigated as a means to deal with all of these problems.  As a basis for the process design, balances were developed for volatile BOD and TRS compounds in pulping and recovery, based on extensive sampling as well as theoretical considerations. Two main alternatives were developed: a Base Case, designed to treat a 3000 m³/d (550 USgpm) contaminated condensate stream, and an Alternative Case, which used further condensate volume reduction measures to treat 1700 m³/d (310 USgpm). Through heat integration with the evaporation plant, the net increase in steam demand was kept to a minimum.  Modeling indicated that condensate stripping would reduce the discharge of volatile BOD by 88% and TRS by 98.5% in the Base Case, while in the Alternative Case the reductions would be 72% and 96%, respectively. Mill management decided to proceed with the Base Case in order to get maximum benefits and to position the mill for future effluent reduction and ultimate mill water system closure.  The condensate stripping system was started up in September, 1993. It has met or exceeded all of its expectations: community odor complaints have dropped essentially to zero, sulfide-caused effluent toxicity has been eliminated, and the BOD in the raw mill effluent dropped by a surprising 12 kg/ADt; 6-8 kg/ADt had been expected based on volatile BOD balances. The rest has been attributed to improved liquor carryover control.

"Feasibility of EPA's Advanced Technology Tiers," E. Mannisto, H. Mannisto, and K. Roos, TAPPI 1997 Environmental Conference and Exhibit, Minneapolis, MN, May 1997.

An integral part of EPA's long-term goals, as declared in the proposed Cluster Rule, is an industry committed to continuous environmental improvement - an industry which aggressively pursues research to identify technologies that reduce and ultimately eliminate  pollutant discharges.  Implementation of pollution prevention technologies by moving towards closed-loop process operation, would increase reuse of recoverable materials and energy while reducing use of raw materials and generation of air emissions and hazardous and non-hazardous wastes.  The proposed Cluster Rule establishes an incentive program consisting of three "Tiers" of BAT limitations beyond the baseline BAT.  The most Advanced Technology Tier (III) limits AOX to 0.05 kg/kkg and the total flow of pulping and evaporator condensates and bleach plant wastewater to 5 m³/kkg....

"Why Energy Conservation?", H. Mannisto and E. Mannisto, TAPPI Engineering Conference, Nashville, TN, October 6-8, 1997.

Energy conservation projects have traditionally been considered as cost reduction measures in the North American pulp and paper industry.  Only a short time after the oil embargo in 1973, fuel availability was a major concern in addition to its cost.  In some other areas, e.g., in Nordic countries, fuel has always been a scarce resource and energy conservation has been a way of life.

Recently, environmental considerations have become key factors in promoting energy conservation.  Concerns for ambient air quality and sustainable use of resources have increased the interest in energy conservation.  In many countries energy conservation has been made more attractive by applying high taxes on purchased energy or by charging fees relative to the amount of pollution discharged to the atmosphere.

The environmental concerns have also led to increased consideration of the entire life-cycle of products.  Various product labels, especially in Europe, have been developed to inform consumers about the environmental impact of products.  The concepts developed by the European Union, for example, take energy use into account in their point scoring schemes.  Very low energy consumption is in many cases required in order to qualify for these Eco-labeling systems.  Due to environmental concerns, the incentives from energy conservation are expected to increase resulting in decreased energy use by the pulp and paper industry.

"Current Environmental Performance of the Pulp and Paper Industry," M. Krogerus, E. Mannisto, and H. Mannisto, TAPPI Minimum Effluent Mills Symposium, Atlanta, GA, January 22-24, 1996.

Environmental performance of the pulp and paper industry has been traditionally through regulation.  The market forces, especially in Europe, are becoming dominant factors in the environmental issues.  The study performed by the authors' organization addressed the current environmental performance and variabilities within the North American and Scandinavian pulp and paper industries.  The study was based mainly on the performance data available from public sources.

The study results show wide variability in the environmental performance of the pulp and paper industry.  Since all the mills are normally in compliance with their limits, this variability is caused by the regulations, which vary widely from mill to mill and from country to country.  Historically, the U.S. Pulp and Paper industry has been the leader in controlling the conventional parameters BOD and TSS by using efficient treatment technologies.  Some of the nonconventional parameters that are affected by process technologies, such as AOX and COD, are controlled more effectively in Scandinavia.  The process technologies used by the mills with the lowest discharges are typically related to pulping and bleaching processes.  Although some newer mills report extremely low discharges, most mills will have to do major modifications in order to approach the minimum impact levels or meet the expected future requirements.

"Who Can Afford to Save Water?", G. Wohlgemuth, E. Mannisto, and H. Mannisto, TAPPI Minimum Effluent Mills Symposium, Atlanta, GA, January 22-24, 1996.

The technical feasibility of low water use technologies has been proven in both pilot and mill scale.  However, although technologies exist, the water and effluent flows are still fairly high in the pulp and paper industry.  Obviously economic factors play a key role in the selection of technologies and water use levels.  Especially for an existing mill, many technical factors determine the minimum required water usage level.  This presentation addresses the economic and technological aspects that have to be taken into account when planning and implementing water conservation measures in an existing mill.  The sample cases presented are from an existing bleached kraft mill.  Water conservation in existing mills is seldom justifiable based on water price alone, but has to be motivated by other process and environmental benefits, such as reduction in energy costs, chemicals, fiber etc.

The optimum water usage level depends on the technologies being used, especially in the pulping and bleaching processes.  This level is determined by factors such as effluent temperature, concentrations that can be tolerated in effluent treatment, effluent toxicity and other parameters that may be defined as maximum concentrations.

"Technical and Economic Feasibility of a Low Effluent Bleached Kraft Mill," H. Mannisto, Envirotech Sympo '96, Vancouver, BC, Canada, April 1, 1996.

The technical feasibility of low effluent concepts has been proven in both pilot and mill scale.  Although technologies exist to lower water usage, water and effluent flows are still fairly high in the pulp and paper industry.  The feasible water usage level depends on the technologies being used, especially in the pulp and bleaching processes.  This level is determined by many factors, such as effluent temperature limitations, concentrations of impurities that can be tolerated in the processes, effluent toxicity and other parameters that are defined as maximum concentrations.  In order to overcome the limitations, new mills in particular have set the goal to completely eliminate process effluents, such as bleach plant effluent.  The mill cases that are reviewed here indicate that the industry is on the way to drastic reduction of effluent discharges.  However, complete elimination of effluent from, e.g., a bleached kraft mill requires further research and mill scale testing before all aspects of the low effluent concepts can be considered proven technology.

"How Green is the Future for Pulp and Paper?", H. Mannisto, E. Mannisto, and M. Krogerus, Papermaker 59:5, May, 1996.

"Who Could be Eco-Labelled:  An International Comparison of the Pulp and Paper Industry's Environmental Performance," L. Kaar, E. Mannisto, and M. Krogerus, ECOPAPERTECH Conference, Helsinki, Finland, June 6-9, 1995.

This paper introduces the criteria applied in the European Union's environmental labelling scheme for paper products.  These recently established guidelines can be divided into resource, energy and emission related parameters and are the compared with the actual environmental performance data from the North American and Scandinavian pulp and paper industries.  The comparison reveals that it would presently be slightly more difficult for the North American producers to achieve the EU eco-label, primarily because of higher AOX discharges, less energy efficient production technologies and higher dependency on fossil fuels compared to their Scandinavian counterparts.