Integration of new processes and geothermal heat into a wood processing cluster

In this study, process integration methods have been used to investigate the heat integration of new processes with a model wood processing cluster. Due to anticipated future demand for bio-derived fuels and chemicals, it is important to identify which emerging conversion processes would benefit from integration with existing facilities. Identifying specific integration schemes help quantify economic and environmental benefits and can assist the commercialisation and adoption of these new processes. The synergies gained through integration are examples of industrial symbiosis, which is the sharing of resources between co-located facilities. A background/foreground analysis of the grand composite curves was used to determine any heat recovery potential between the cluster and the new entrant and the effect on the utility system. The model cluster consisted of a thermo-mechanical pulp and paper mill, kraft pulp and paper mill and saw mill. Some of the processes had little or no integration potential due to having similar pinch temperatures as the cluster. Processes based on biomass gasification had large potential due to the pinch temperatures being very different and the shape of grand composite curve being complimentary. The integration of geothermal energy for process heat was also investigated and if available has a distinct advantage of allowing surplus black liquor to be used as a feedstock to some of the new processes. Results show that high pinch temperature processes show the greatest integration potential and can provide significant fuel reduction potential.