Cascade Membrane System for Separation of Water and Organics from Liquid By-Products of HTC of the Agricultural Digestate—Evaluation of Performance
Agnieszka Urbanowska,
Małgorzata Kabsch-Korbutowicz,
Christian Aragon-Briceño,
Mateusz Wnukowski,
Artur Pożarlik,
Lukasz Niedzwiecki,
Marcin Baranowski,
Michał Czerep,
Przemysław Seruga,
Halina Pawlak-Kruczek,
Eduard Bramer,
Gerrit Brem
Affiliations
Agnieszka Urbanowska
Department of Water and Wastewater Treatment Technology, Faculty of Environmental Engineering, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
Małgorzata Kabsch-Korbutowicz
Department of Water and Wastewater Treatment Technology, Faculty of Environmental Engineering, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
Christian Aragon-Briceño
Department of Thermal and Fluid Engineering, University of Twente, Postbus 217, 7500 AE Enschede, The Netherlands
Mateusz Wnukowski
Department of Energy Conversion Engineering, Faculty of Mechanical and Power Engineering, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
Artur Pożarlik
Department of Thermal and Fluid Engineering, University of Twente, Postbus 217, 7500 AE Enschede, The Netherlands
Lukasz Niedzwiecki
Department of Energy Conversion Engineering, Faculty of Mechanical and Power Engineering, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
Marcin Baranowski
Department of Energy Conversion Engineering, Faculty of Mechanical and Power Engineering, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
Michał Czerep
Department of Energy Conversion Engineering, Faculty of Mechanical and Power Engineering, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
Przemysław Seruga
Department of Bioprocess Engineering, Wroclaw University of Economics, Komandorska 118/120, 53-345 Wrocław, Poland
Halina Pawlak-Kruczek
Department of Energy Conversion Engineering, Faculty of Mechanical and Power Engineering, Wroclaw University of Science and Technology, Wybrzeże Wyspiańskiego 27, 50-370 Wrocław, Poland
Eduard Bramer
Department of Thermal and Fluid Engineering, University of Twente, Postbus 217, 7500 AE Enschede, The Netherlands
Gerrit Brem
Department of Thermal and Fluid Engineering, University of Twente, Postbus 217, 7500 AE Enschede, The Netherlands
New regulations aimed at curbing the problem of eutrophication introduce limitations for traditional ways to use the by-product of anaerobic digestion—the digestate. Hydrothermal carbonisation (HTC) can be a viable way to valorise the digestate in an energy-efficient manner and at the same time maximise the synergy in terms of recovery of water, nutrients, followed by more efficient use of the remaining carbon. Additionally, hydrothermal treatment is a feasible way to recirculate recalcitrant process residues. Recirculation to anaerobic digestion enables recovery of a significant part of chemical energy lost in HTC by organics dissolved in the liquid effluent. Recirculating back to the HTC process can enhance nutrient recovery by making process water more acidic. However, such an effect of synergy can be exploited to its full extent only when viable separation techniques are applied to separate organic by-products of HTC and water. The results presented in this study show that using cascade membrane systems (microfiltration (MF) → ultrafiltration (UF) → nanofiltration (NF)), using polymeric membranes, can facilitate such separation. The best results were obtained by conducting sequential treatment of the liquid by-product of HTC in the following membrane sequence: MF 0.2 µm → UF PES 10 → NF NPO30P, which allowed reaching COD removal efficiency of almost 60%.
