Graphene oxide membrane could cut energy needed for solvent purification
Researchers at the University of Bath have helped develop a graphene oxide membrane that could reduce the energy required to purify one of the chemical industry's most widely used solvents.
Working with an international team led by KU Leuven, the researchers demonstrated a membrane technology capable of separating water from isopropanol more quickly and with lower energy demand than conventional purification methods. The findings have been published in Nature Communications.
Separating chemical mixtures into their pure components is one of the most energy-intensive operations in industrial chemistry, accounting for an estimated 10 to 15% of global energy use. Isopropanol, which is widely used in pharmaceutical manufacturing and electronics, is typically purified using heat-intensive distillation processes that contribute significantly to energy consumption and carbon emissions.
The research team developed a membrane based on graphene oxide, an ultrathin carbon material, by combining conventional graphene oxide sheets with new variants containing smaller pores. The resulting internal structure incorporates narrow channels that block larger molecules while creating regions that selectively attract and transport water molecules.
Professor Bart Van der Bruggen, lead researcher on the project at KU Leuven, said: "With the growing demand for more sustainable production processes, more efficient separation techniques are essential to continue using isopropanol, also in its bio-based forms from renewable resources, on a large scale."
Lei Jiang, a doctoral researcher at KU Leuven, said designing the membrane required balancing separation speed with purity.
"The main challenge is to design a structure where the channels are not too small, which would slow down the separation and require more energy, but also not too large, which would reduce the purity of the final product," Jiang said.
"The new membrane combines both efficient and high-quality separation in a single structure."
Dr Pengrui Jin, prize fellow in the University of Bath's Department of Chemical Engineering and an independent principal investigator on the study, said the membrane was able to selectively remove water from a mixture containing 90% isopropanol and 10% water.
"The new membrane efficiently removes water from a mixture containing 90% isopropanol and 10% water," he said. "It selectively transports the water through the membrane, producing a permeate containing about 99.6% water. In addition, the process is faster than existing techniques and requires less energy, as it does not rely on high temperatures."
According to the researchers, the technology offers improvements in product purity, energy consumption and economic efficiency while supporting efforts to reduce the environmental impact of chemical manufacturing. The team is now investigating whether the membrane can be applied to other industrial chemical mixtures and is exploring opportunities to scale up the technology and assess its commercial potential through patent protection.
The study, Solvent dehydration with structurally engineered nanoporous graphene oxide membranes, involved researchers from KU Leuven, the University of Bath, Huazhong University of Science and Technology, Nanjing University, Monash University, Korea University and VSB-Technical University of Ostrava. Pic: Roman Kaiuk
