Purification and retention of sucrose in sugar beet molasses by utilizing ceramic nanofiltration membranes

Research output: Contribution to conferenceAbstract


Biorefineries are rapid growing branches in the world of sustainable chemical engineering, and one aspect that becomes more and more important is the reuse and valorization of different by-products. In sugar mills, molasses is a low value by-product mainly used for animal feed. However, a large part of the molasses contains the main product of the sugar mill: sucrose. By using membrane filtration, it is possible to purify the sucrose in the molasses. The sucrose could then either be recirculated back to the main stream of the sugar mill or be used for other various processes, for instance, biotechnological conversion of sugar to high value bio-based polymers. A small scale tubular ceramic nanofiltration membrane with a molecular weight cut-off of 200 Da has been investigated for purification of sucrose in sugar beet molasses. This membrane can not just purify the sucrose by removing salts and other small molecules, but can also concentrate the sucrose. The trials were conducted in a crossflow setup at 60 ˚C. In order to pump around the molasses in the crossflow system, the molasses required to be diluted first. Two dilutions were investigated: 0.5 % and 10 % molasses in distilled water. For each dilution, two different types of tests were conducted: a process parameter study and a concentration study. The impact on the filtration fluxes was monitored for different pressures and crossflow velocities. The fouling degree and filter cleaning efficiency was also studied, where the effect of different cleaning agents was investigated. The retention of various compounds was evaluated using refractive index, conductivity and turbidity. The results indicate that it is possible to retain sugar with the ceramic nanofiltration membrane, and at the same time achieve high filtration fluxes (up to 270 L/(m2 h), during the 0.5 % molasses concentration test). It is also possible to clean the ceramic membrane efficiently and recover the filtration capacities back to original levels, even after being heavily fouled.


Research areas and keywords

Subject classification (UKÄ) – MANDATORY

  • Chemical Engineering


  • Membrane processes, Biorefineries
Original languageEnglish
Number of pages1
Publication statusPublished - 2019 Apr 8
Publication categoryResearch
EventEngineering with Membranes 2019: Membranes for a sustainable future - Hotel Skansen, Båstad, Sweden
Duration: 2018 Apr 82019 Apr 10


ConferenceEngineering with Membranes 2019
Abbreviated titleEWM 2019
Internet address