This project aims to develop and use advanced characterisation methods to investigate how process parameters can be utilised to decrease the effect of surface fouling during separation for recovery of high molecule weight hemicelluloses in biorefinery applications. Characteristics of formed fouling layers that are difficult to measure: thickness as well as cohesive and adhesive strength, will be investigated in-situ and related to process parameters to develop strategies to limit the effect of fouling on the separation operation.