Natural Resources Institute Finland (LUKE) made a survey on the alternative uses of side streams of wood processing in Woodpolis industrial area in the City of Kuhmo. Woodpolis Timber Cluster consists of Kuhmo Ltd.’s large saw mill and some ten SME companies specialised in further processing of sawn timber and side-streams of wood processing. A good example of new growing industries in the area are CLT, cross laminated timber and element factories producing prefabricated building products for multi-storey and one-storey buildings, such as residential, office, school and kindergarten houses.
In addition to saw mill chips supplied to pulp mill, versatile side streams from saw dust and bark to massive left-over pieces of log house and CLT construction are produced in the area. In 2015, of the total amount of 475,000MWh of bioenergy from the side streams 376,000MWh was used at the local CHP plant or for the briquette and pellet production, and 99,000MWh was sold to other CHP plants in Northern Finland. However, oversupply of wood chips and pellets for bioenergy as well as long transport distances reduce the profitability of selling the entire excessive bioenergy fraction. Increase of pellet or briquette production is not seen very profitable either. Therefore, new ways of utilizing side streams are actively sought.
The most technically challenging side-stream fraction is CLT leftover pieces because of their variation in shape, dimensions and chemical composition. Once the product is piled up with gluing, chipping it back to bioenergy or bio-refinery fractions is not easy or reasonable. New ways of utilizing them are sought from packaging and wood panel industries. If chipped, semi-finished products for manufacturing of for example wood-plastic composites should be given preference over bioenergy uses.
Bioethanol production would be a feasible step in the further processing of more advanced biofuel products from saw dust, planer shavings and bark. Biochar production for purposes which require bioactivity from the char, or for metallurgic processes may also provide promising options. In addition, saw dust and bark contain extracts some of which are already in the markets: for example, pine tar, turpentine, pyroligneous acid, and adhesives. However, bio-refineries (e.g. bioethanol plants) usually require large amounts of raw materials to be technically feasible and economically profitable, much more than what is generated now in Woodpolis industrial area.
Probably, the best potential for local bio-refinery production would be in high priced bioactive compounds or upgraded raw materials intended for uses like in health products, cosmetics, or food products. In all cases, new bio-refinery production in the Woodpolis area requires investments and operating capital, and attraction for new initiated entrepreneurship. There are no ready-made solutions for a new bio-refinery production. Technical implementation must be planned and tested on a realistic raw material basis and market perspective with a convincing proof-of-concept before the start of a full scale production. If they are realized, the new large-scale bio-refinery projects going on in Northern and Eastern Finland, St1’s bioethanol factory and KaiCell Fiber’s pulpmill and related bio-refinery activities being the closest, may increase quickly the demand of the side-streams generated in the Woodpolis industrial area.
The entrepreneurial community of Woodpolis Timber Cluster has worked together for a long time, which has enabled the refinement of joint development work and common practices. Therefore, Woodpolis can offer an example for other wood-based industrial clusters of the same kind about good practices, collaboration between SMEs and large companies regarding cooperation and new options to acquire and market raw materials, as well as product and service development activities.