Vacuum Evaporation of Process Water from Recycled Containerboard Mills

This work demonstrates for the first time in a long-duration pilot plant study, the successful use of evaporation to reclaim water from the process water of a recycled containerboard mill without negative impact on its energy balance. For this purpose, a custom-built low-temperature vacuum evaporator pilot plant was installed on-site at a paper mill to investigate operation, selective separation efficiency, and feasibility under relevant conditions. This research shows that by implementation of evaporation in recycled containerboard mills the current technical limitation to water system closure can be overcome and the transition towards a circular economy is accelerated.