Developed by a team of researchers from the Georgia Institute of Technology, Imperial College London, and ExxonMobil, new membrane technology can help reduce the carbon footprint and energy intensity associated with crude oil refining. Laboratory tests show that this polymer membrane technology could replace some of the traditional thermal distillation processes in the future. The study publishes the journal Science.
Fractionating crude oil mixtures using thermal distillation is a large-scale, energy-intensive process, accounting for nearly 1% of global energy consumption: 1,100 terawatt-hours per year (TWh / year). This is equivalent to the total amount of energy that New York State consumes per year. When introducing low-energy membranes at certain stages of the distillation process, a new technology may one day allow the introduction of a hybrid purification system. It can help significantly reduce carbon emissions and energy consumption compared to traditional cleaning processes.
Much of modern life is tied to oil, so the separation of its molecules is important for civilization. The scale of separation required to provide petroleum products is incredibly large. This membrane technology can have a significant impact on global energy consumption and associated emissions from oil refining, scientists say.
Membrane technology is already widely used in areas such as desalination, but the complexity of oil refining has so far limited the use of membranes. To overcome this problem, the research team developed a new spirocyclic polymer, which was applied to a strong substrate to create membranes. They are able to separate complex hydrocarbon mixtures by pressure rather than heating.
Membranes separate molecules from mixtures according to size and shape. When the molecules are very close in size, this separation becomes more complex. Scientists have been able to balance a variety of factors to create the right combination of solubility, to allow small molecules to pass through them more easily than others. Researchers found that materials needed a little structural flexibility to improve dimensional discrimination, as well as the ability to be slightly “sticky” to certain types of molecules that are found in abundance in crude oil.
After developing new polymers and achieving some success using a mixture of synthetic gasoline, jet fuel, and diesel fuel, the team decided to try to separate a sample of crude oil and found that the new membrane was very effective in extracting gasoline and jet fuel.