Added value from biomass by broader utilization of fuels and CHP plants

The present work, where additional value-creating processes in existing combined heat and power (CHP) structures have been examined, is motivated by a political- and consumer-driven strive towards a bioeconomy and a stagnation for the existing business models in large parts of the CHP sector. The research is based on cases where the integration of flash pyrolysis for co-production of bio-oil, co-gasification for production of fuel gas and synthetic biofuels as well as leaching of extractable fuel components in existing CHP plants have been simulated. In particular, this work has focused on the CHP plants that utilize boilers of fluidized bed (FB) type, where the concept of coupling a separate FB reactor to the FB of the boiler forms an important basis for the analyses. In such dual fluidized bed (DFB) technology, heat is transferred from the boiler to the new rector that is operating with other fluidization media than air, thereby enabling other thermochemical processes than combustion to take place. The result of this work shows that broader operations at existing CHP plants have the potential to enable production of significant volumes of chemicals and/or fuels with high efficiency, while maintaining heat supply to external customers. Based on the insight that the technical preconditions for a broader operation are favourable, the motivation and ability among the incumbents in the Swedish CHP sector to participate in a transition of their operation towards a biorefinery was examined. The result of this assessment showed that the incumbents believe that a broader operation can create significant values for their own operations, the society and the environment, but that they lack both a strong motivation as well as important abilities to move into the new technological fields. If the concepts of broader production are widely implemented in the Swedish FB based CHP sector, this can substantially contribute in the transition towards a bioeconomy.

Bioeconomy has been identified to hold a great potential for reducing fossil fuel dependence and for maintaining and creating economic growth. Large parts of the combined heat and power (CHP) sector, which successfully have contributed in the transition towards a fossil free society, are at present facing stagnation. District heating actors are facing challenges due to warmer climate, better insulated buildings and competition from heat pumps. The forest industry where CHP plants supplies processes with heat is facing structural changes foremost in the graphic segments. The emerging bioeconomy and the stagnation for the existing business models in large parts of the CHP sector form the background for the examination of additional value-creating processes in the existing CHP structure presented in this thesis. The technical viability for integration of fast pyrolysis, gasification and leaching with existing CHP plants has been analysed as well as the motivation and ability of the CHP incumbents to participate in a transition towards the bioeconomy by developing their plants to biorefineries.