Commercial thermo-responsive polyalkylene glycols as draw agents in forward osmosis

Commercial thermo-responsive polyalkylene glycols as draw agents in forward osmosis

Forward osmosis (FO) is a promising technology for efficient water reclamation at low operating costs. It has shown potential in producing fresh water from seawater; however, the regeneration of the diluted draw solution (DS) still holds back further development. Thermo-responsive polymers, especially polyalkylene glycol (PAG) based copolymers with hydrophilic ethylene oxide and hydrophobic propylene oxide units, have shown suitability as DSs in FO using low-temperature waste heat to regenerate the DS. In this study, we explored five commercially available copolymers: Pluronic® PE 6400, Pluronic® L-35, Pluronic® RPE 1740, Unilube® 50 MB-26, and Polycerin® 55GI-2601 as DSs in a laboratory FO setup, with DI water as the feed solution (FS). The water
flux and reverse solute flux varied from 1.5 to 2.0 L⋅m􀀀 2⋅h􀀀 1 and from 0.04 to 0.4 g⋅m􀀀 2⋅h􀀀 1, respectively.

Furthermore, all polymer solutions showed the ability to be recovered and reused using temperatures below 100◦C. Therefore, the tested PAGs turned out to be promising as draw solutions for FO systems that utilize low-grade waste heat. The re-usage in FO was shown for regenerated Pluronic® L-35 through a three-step experiment where its recovery was 91.1 %, 93.1 %, and 91.9 % for each FO cycle, respectively.

Keywords: Forward osmosis, Draw solution, Osmotic pressure, Polyalkylene glycols, Lower critical, solution temperature, Reuse of polymer.

Authors: Irena Petrinic, Natalija Jancic, Ross D. Jansen van Vuuren, and Hermina Buksek.

Soós Ernő International Scientific Conference (VSZI’23)

Soós Ernő International Scientific Conference (VSZI’23)

After presenting the ‘Implementation of thermo-responsive polyalkylene glycol-based draw solutions in the forward osmosis process‘ (co-prepared by I. Petrinić, N. Jančič, and H. Bukšek) at Soós Ernő’s international scientific conference on Water and wastewater treatment in the industry in 2022 (VSZI’22), our project partner, the University of Maribor, is back with a new presentation for the 2023 edition!

Irena Petrinić, Ross D. Jansen-van Vuuren, Ana Ambrož, Thomas Luxbacher, and Hermina Bukšek, from the University of Maribor (DESOLINATION partner) gave an oral presentation focusing on ‘Thermo-responsive PAG based commercial draw solutions for forward osmosis‘ at Soós Ernő 2023 (VSZI’23) organised by the Soós Ernő Research and Development Center, University of Pannonia Nagykanizsa – University Center for Circular Economy and the Foundation for Higher Education of Kanizsa.

The production of clean drinking water is also a priority in countries with abundant water resources and growing solvent demand. The main goal of the research center, founded in 2014, is to carry out international researches in the field of water purification and water treatment, by using the research results and experience in water purification and water treatment in the Nagykanizsa region which is based on decades of history. It is also of utmost importance for us to train specialists who are able to solve various water and waste water treatment problems in industries and public utilities.

In order to support this goal and provide the future professionals, talent management is needed. Elementary and high school students can have the insight into the work of the research center as we offer them lectures, open lab sessions and summer camps, all promoting natural sciences.

The annual Soós Ernő International Scientific Conference, through the presentations and discussions of scientific and industrial professionals in the field of water and waste water treatment, will allow knowledge sharing, networking and exchange of experience which are essential for development,

Characterization of the physical properties of the thermoresponsiveblock-copolymer PAGB2000 and numerical assessment of its potentialities in Forward Osmosis desalination

Characterization of the physical properties of the thermoresponsiveblock-copolymer PAGB2000 and numerical assessment of its potentialities in Forward Osmosis desalination

Forward Osmosis is a promising strategy for desalination processes, however some aspects have to be better characterized to make it competitive with other affirmed technologies. One of these aspects is the selection of the draw agent, i.e., a polymeric solution that has to fulfill different requirements to guarantee both high membrane performances and good regeneration process. Previous studies have identified a thermoresponsive copolymer known as PAGB2000 as potential draw agent. However, in the open literature there is no information on the thermo-physical properties required for a fully characterization of the polymer itself, hence, different experimental campaigns have been conducted to quantify: phase behavior, osmotic pressure, density, dynamic viscosity, thermal conductivity, thermal diffusivity and isobaric specific heat capacity. These properties were then used in a computational model to simulate the whole desalination process. Recovery ratio, specific electric consumption and specific thermal consumption were compared with the ones obtained in a previous work, showing that a detailed characterization of the thermo-physical properties is required to get accurate and realistic predictions of the system performance.

Keywords: Polymer, Draw agent, Forward osmosis, Desalination.

Authors:

, , , , , , , , ,