High-efficiency evaporation technology for pulp-mill based biorefineries

The project aims to reduce the problems of deposits on heating transfer surfaces of black liquor evaporators. The evaporation plant is currently the largest steam user at a pulp mill. The evaporation plant’s capacity and operational availability is affected by the fact that even in normal operation, fouling may form on its surfaces. Generally the evaporators are over-designed with 15-25% to handle this problem and the fouling also causes a regular need of washing. The project intends to study the crystallization process that causes the fouling and how it can be affected by varying the size and distribution of crystals. Would the method to be used in the project be proven successful, we believe that a commercially available technology based on this research proposal, applicable to both new and existing installations, would be available within one year after completion of the project.