HELPED TO MAKE SWEDISH PULP INDUSRTY MORE RESOURCE-EFFICIENT
The Ecocyclic Pulp Mill (Kretsloppsanpassad massafabrik, KAM) research programme started in 1996 in response to new, more stringent environmental requirements imposed on the pulp industry and also the industry’s own ambitions. The overarching objective was to develop solutions to produce high-quality pulp and paper products that minimised the use of non-renewable resources and made efficient use of the potential of biomass. Another aim was to propose basic solutions for making the sulphate-pulp process an almost entirely closed cycle (or loop), in order to reduce its waterborne effluents, improve the air around pulp mills and boost resource efficiency.
WHAT RESULTS HAS THE PROGRAMME HAD?
During its eight years, the programme yielded numerous results. Several of these are now being used industrially on a large scale in Sweden and other countries. One of the most important results concerned the recovery of lignin, a by-product, from the black liquor that is formed in the pulp process. This method is known astheLignoBoost process. Through the extraction of lignin from the black liquor, high-volume capacity is freed in pulp production without heavy investments being needed. The lignin can be recovered and used as biofuel and for high-performance light materials, such as carbon fibre, which affords both environmental and economic gains.
‘KAM represented something new. The comprehensive approach adopted was unusual for research at the time. The whole pulp process, including treatment facilities, was considered and the researchers took operating accessibility as well as economic, energy and environmental factors into account. One result was a reference pulp mill that we’ve found immensely useful both in our internal development work and in dialogue with government agencies in licensing cases.’
Karin Emilsson, Director of Technology, Södra
In the course of the programme, a pilot plant for LignoBoost was started at Bäckhammar. The programme also generated a series of other results that were implemented in industry, including better cooking and bleaching conditions that yield a whiter paper. New ways of bleaching the pulp that afford higher efficiency and lower waterborne effluents were developed. KAM also resulted in more efficient energy estimates and methods of closing the cycle of the bleaching process. At a pulp mill on Lake Vänern, methods developed by KAM that reduce cadmium loads in the water, are being applied.
WHO HAS BENEFITED FROM THE RESEARCH?
The pulp industry received both immediate and long-term benefits from KAM. Besides LignoBoost, which is the outcome of a collaboration between Innventia, a Swedish research institute (formerly STFI-Packforsk, the Institute for Packaging and Logistics, a division of the Swedish Pulp and Paper Research Institute) and Chalmers University of Technology, other results mentioned above have been implemented in the industry. KAM has also generated better knowledge and understanding of industrial issues in academia, and contributed new trained researchers with contacts in industry.
Since the programme ended in 2004, the research has continued. In 2013 the first full-scale plant for making LignoBoost opened in the United States. The research is also highly advanced in terms of making carbon fibre from lignin, which is believed to be a potential material in the vehicles of the future, to make them lighter, for example.