Johanna Jönsson

Increased thermal efficiency in Scandinavian integrated TMP and paper mills – analysing the potential for steam savings using the heat load model for pulp and paper

In this paper the potential for steam savings and excess heat levels is analysed for four Scandinavian TMP mills using the Heat Load Model for Pulp and Paper (HLMPP). The results are compared with similar results from previous studies for two other TMP mills. Further, an analysis is made regarding the linkage between the steam consumption and temperature level of excess heat and mill specific characteristics such as e.g. production rate and fresh warm water usage. Based on the results and the analysis the potential for implementation of different biorefinery concepts is discussed. The results indicate that steam savings of 2-20 % can be found in Scandinavian TMP mills. The pinch temperature is rather low, around 0-70 °C for most of the studied TMP mills, compared to the pinch temperature usually found at kraft pulp mills (100-140 °C) and thus the potential utilization options for the excess heat is rather limited. The results also show that the level of heated fresh water is affecting both the steam consumption and the pinch temperature and thus also the potential for efficient integration of different biorefinery processes.

Pathways to a sustainable European pulp and paper industry: Trade-offs between different technologies and system solutions for kraft pulp mills

Earlier studies have shown that for chemical pulp mills there are many technologies and system solutions which can increase energy efficiency and thus reduce the process energy demand and consequently also the global emissions of CO2. Which technology pathway (combination of technologies and system solutions) holds the greatest potential for future profits and reduction of global CO2 emissions depends both on mill-specific conditions and on the surrounding energy system through e.g. policy instruments and energy market prices. In this paper the trade-off, in terms of system revenue and global CO2 emission consequences, between different technology pathways for utilization of excess heat at chemical kraft pulp mills is investigated for a case depicting a typical Scandinavian mill of today. The trade-off is analysed for four future energy market scenarios having different levels of CO2 charge. The technology pathways included in this study are (1) increased electricity production in new condensing turbines, (2) production of district heating, (3) increased sales of biomass in the form of bark and/or lignin, and (4) carbon capture and storage (CCS). Lignin extraction and CCS are considered as new and emerging pathways and the other pathways are considered to be well-tried. The results show that well-tried pathways such as increased electricity production in new turbines, selling bark and district heating production are economically robust, i.e. they are profitable for all of the studied energy market scenarios. The new and emerging technology pathways such as carbon capture and storage and lignin extraction hold a larger potential for reduction of global CO2 emissions, but their economic profitability is more dependent on the development of the energy market. All in all, it can be concluded that to realize the larger potential of reduction of global CO2 emissions a high carbon cost alone may not be sufficient. Other economic stimulations are required, e.g. technology-specific subsidies.

Towards a Sustainable European Energy System - The Role of the Pulp and Paper Industry

In this paper a methodology for analyzing the potential for and effect of implementation of different technology pathways within the pulp and paper industry, developed by the Heat and Power Technology research group at Chalmers University of Technology, is presented. The methodology assumes detailed research and is based on bottom-up thinking. To exemplify its usefulness two studies applying the methodology are summarized. All in all, it can be concluded that the presented methodology enables integration of the different research projects, connecting research on different system levels with each other, which in turn gives the research group the possibility to better answer questions regarding the development and future role of the pulp and paper industry on a higher system level whilst still considering important characteristics of individual technologies and/or mills.