Optimisation of black liquor evaporation for pulp industry

Important results from the project

Factors reducing scale formation during evaporation of black liquor at an existing softwood kraft pulp mill have been identified and active compounds have been analyzed and identified. Information and experience obtained during the project have been applied in laboratory experiments, where both increased concentration of dissolved inorganic salts during evaporation was achieved, as well as changes in inorganic precipitates. According to the results, problems with scale formation can be reduced with addition of identified substances.

Expected long term effects

The first part, phase 1, is achieved by the decrease in scale formation after addition of identified substances at an appropriate stage during evaporation. According to experiments, it is possible to both increase the concentration of inorganic salts in solution and precipitate inorganic compounds in the bulk. The possibilities to implement the approach on the target market is further strengthened, since the methodology utilizes a dual and complementary approach.

Approach and implementation

The project has been implemented in accordance with the original plan, where RISE Bioeconomy/Biorefinary & Energy has been consulted regarding analysis and laboratory studies. We have achieved successful synergies by combining our areas of expertise, which bode well for future project opportunities.