• "bioenergy"
• "high temperature heat pump"
• "industrial decarbonization"
• "process heat"
• "tissue paper"

Tissue paper production is energy-intensive, necessitating high power input and elevated temperatures compared to other paper grades due to its low basis weight (typically under 20 g/m²) and high production speeds (up to 2000 m/min). Although tissue paper is produced in lower volumes than packaging materials, its societal importance and annual demand growth of 3.3% emphasize the need for decarbonization strategies in this sector, which is required under the Emission Trading Scheme (ETS) to achieve a 62% reduction in greenhouse gas emissions by 2030. This thesis explores viable decarbonization pathways for tissue production, focusing on fuel switching to bioenergy and electrification, with particular attention to the economic feasibility of these solutions and their interaction with resource availability. As a methodology, a comprehensive decarbonization strategy centered on bioenergy and high-temperature heat pumps (HTHPs) was developed, based on the operating conditions of a typical tissue paper facility. Process simulations in HySys identified modifications to enhance HTHP efficiency and reduce energy consumption.
The economic analysis results suggests that achieving viable payback times is contingent on biomass costs below 25 €/MWh—a price more feasible in Northern Europe, where bioenergy is more prevalent. Despite higher upfront costs, these bioenergy-based solutions present a competitive decarbonization option compared to direct electrification, which currently entails 85-200% higher costs than conventional systems. Carbon taxation, such as a 100 €/tCO2 levy, could help offset these costs, especially in regions like France, where nuclear power lowers the cost disparity between electricity and natural gas. Additionally, integrating infrared (IR) drying could limit cost increases to approximately 11%, though further assessment is warranted.
A scenario where all tissue paper mills adopt resistive heating systems at the European level would result in an additional annual electricity demand of 8.4 TWh, raising overall demand by approximately 55% to 130%. Implementing HTHP solutions could mitigate this increase, reducing it to 24%–86%, while systems that combine HTHP and IR lamps could limit the rise to between 0% and 50%. Conversely, biomass-based systems may face challenges due to uneven biomass availability and the sustainability of transporting low-density biofuels over long distances. A hybrid approach incorporating both electrification and biomass could mitigate these challenges, reducing overall biomass demand and logistics strain. Combining HTHPs with biomass gasification could provide a viable solution for individual facilities, where HTHPs supply steam while biomass gasification meets the high-temperature air requirements (350°C-500°C) necessary for tissue production, thereby reducing dependence on local renewable resources and overall energy costs.
In conclusion, to meet the 2030 emission targets, widespread implementation of biomass-supported HTHPs is critical. HTHPs align well with tissue production's temperature requirements (100°C to 200°C), representing 20-25% of industrial heat demand, and are particularly compatible with production processes that emit humid exhaust gases (70°C to 150°C). Given their potential impact on industrial decarbonization, HTHPs are strong candidates for public funding, potentially supported by ETS revenues, making tissue mills an ideal setting for implementing these technologies.