Strategies to minimize fouling in black liquor evaporators

Research Project, 2016 – 2020

Black liquor is an important by-product of the pulping process, containing large amounts of cooking chemicals and energy that needs to be recovered. The first step in this process is to increase the concentration of the black liquor in the evaporation plant, which is the single most energy consuming unit at the mill. The evaporation plant is known to have problems with fouling which drastically reduces the capacity and the plant's energy efficiency. Fouling leads to a need for regular cleaning, it can cause major disturbance and, at worst, production loss for the whole mill.

By a combination of case studies and studies in pilot scale, the project aims to develop new strategies for industrial black liquor evaporators to minimize fouling and thus increase energy efficiency in the mills, as well as to reduce the frequency of major problems. The project will be a close collaboration with both an equipment supplier and pulp mills, and links to earlier research at Chalmers in the field.