Södra Cell Mönsterås produces 750 000 tonnes of sulphate pulp annually from both softwood and hardwood. Södra Cell is also a major producer and supplier of biofuels, green electricity, district heating and raw material for liquid biofuels.
Black liquor is the by-product of chemical pulping. It contains inorganic cooking chemicals, alkali and sulphur compounds, along with the lignin and other organic matter separated from the wood during pulping in the digester. The initial concentration of weak black liquor is about 15 % dry solids in water and increases during processing to 65 – 85 % in an evaporation plant. It is then burned in the black liquor recovery boiler, se figure, and the smelt is tapped and further processed to recover the cooking chemicals. As black liquor is highly corrosive, corrosion resistant materials in pipes and cisterns are required to avoid damage to the system.
This project focuses on designing thin films that can be used to coat surfaces that come in contact with black liquor. You will synthesize films using physical vapor deposition, characterize them with e.g. electron microscopy and x-ray diffraction, and test their corrosion resistance both using model liquids and black liquor from Södra. The aim is to understand how the coatings can withstand the harsh black liquor, and how variations in the film composition affects the corrosion resistance. The project will be performed at LiU, with regular site visits at Södra Cell in Mönsterås. The corrosion tests will be done at RISE in Kista.
Examiner: Emma Björk (email@example.com, contact person)
Supervisors: Daniel Lundin (firstname.lastname@example.org) and Jenny Larfeldt (email@example.com)