Integration of biomass gasification with a Scandinavian mechanical pulp and paper mill

Paper i proceeding, 2011

The Scandinavian mechanical pulp and paper industry has been facing great challenges during the past decades, mainly because of a declining demand for newsprint, and higher prices on raw material and energy. One way of increasing profitability is to produce more value-added products besides the production of pulp and paper, thus creating a “biorefinery”. Gasification of residues from forestry, falling bark and cutter shavings has been raised as a promising option for utilizing low-value biomass to produce syngas, which can be further synthesized to, for example, transportation fuels or chemicals. In this paper, the results of a case study on biomass gasification integrated with a Swedish thermo-mechanical pulp and paper mill (TMP mill) are presented. The mill has an annual paper production of 760 000 tonnes and is co-located with a large saw mill. The demand for raw material to the saw mill is about twice as large as the product output, on a volume basis, which potentially leaves a substantial raw material base for a gasifier. A simplified pinch analysis using the HLMPP (Heat Load Model for Pulp and Paper) tool has earlier been performed for the studied TMP mill. This paper evaluates the integration of biomass gasification, including production of electricity or liquid transportation fuels, with the studied TMP mill. It also presents the impact of such integration on the overall heat and mass balances. Proper pre-treatment of the biomass prior to gasification as well as treatment of the product gas have also been evaluated with respect to heat integration aspects. The results of this initial study indicate an interesting match between the constituting parts, i.e. the pulp and paper mill, the saw mill and the production of electricity and transportation fuels. This work will therefore be followed by an economic evaluation based on a more technically detailed study.