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

Abstract

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.