Opportunities for biorefineries in the pulping industry

Increased energy and raw material prices along with tougher competition and contracting markets for pulp products have highlighted the need for the pulp industry to enlarge their traditional product portfolio with new value-added products. There is also a strong growing interest from society to replace petroleum-based products with products from renewable sources. The spent cooking liquor in a kraft pulp mill, called black liquor, is today used for electricity and steam production, but it could partly be converted into other valuable products, making use of the chemical structures of complex organic compounds derived from the wood components. Moreover, the cellulose fraction which is currently used for paper products can be used for other purposes, such as production of biofuels or specialty cellulose products. In addition, there are new possibilities to make use of low quality biomass, for example forest residues. The pulp mills have good prerequisites to become the future biorefineries. Firstly, the scale of the industry means both large volumes of biomass feedstock in large production sites permitting economies of scale. Secondly, some by-product streams, e.g. black liquor, are already partly processed in pulp production and can be more suitable for further refining than wood waste, agro fibres or other natural- fibre feedstock. Biomass is a more complex raw material than petroleum and utilizing partly processed streams permits a very efficient resource use. Thirdly, location of the new industries at the pulp mill means excellent process integration opportunities (access to heat sources and heat sinks, waste and effluent handling, water, general infrastructure and logistics)