A research panel from the Georgia Institute of Technology and ExxonMobil has illustrated a novel carbon-based molecular sieve membrane that can drastically diminish the energy needed to segregate a group of hydrocarbon molecules termed as alkyl aromatics.
The novel substance is grounded on polymer hollow fibres treated to retain their pore sizes and structure as they are transformed to carbon through pyrolysis. The membranes of carbon are then utilized in a novel ‘organic solvent reverse osmosis’ OSRO procedure in which pressure is applied to effect the separation without needing a phase change in the chemical mixture.
Figure 1: Holding bundles of hollow polymer fibers
The hollow carbon fibres, linked together into modules can detach molecules whose size differs by a proportion of a nanometre while delivering processing rates bigger to those of present molecular sieve zeolites. It is because, it utilized a commercial polymer precursor the scientists believe the novel membrane has space for commercialization and integration into chemical processes based on industrial applications.
The separation is presently obtained through refining processes like absorption and crystallization with distillation which are energy intensive. Universally, the volume of energy utilized in traditional separation procedures for alkyl aromatics is equal to that generated by about 20 percent average-sized power plants.
"We considered this as a potentially disruptive technology in the method, we detach xylenes and equally organic compounds," says Benjam McCool, one of the member of the research team. "If we can make this happen on an industrial scale then it could drastically diminish the energy needed by these detaching procedures."
Fabrication of the novel membrane material instigates with hollow polymer fibres approximately 200 microns in a diameter, slightly bigger than the average human hair. The fibres possess pore sizes of less than one nanometer and are treated through cross-linking before they are transformed to carbon through the process of pyrolysis. It is even possible to adjust the pore size of carbon during process of fabrication.
"Because we are beginning with commercially – available polymers and we are utilizing commercial sort off equipment, we can witness a precise line of sight to commercialization with such technology," says McCool. "It is a great benefit that such membranes are being spun on a hollow-fibre line similar to that presently utilized in the industry. The time horizon to allow this happens and the overall expenditure of production could be highly beneficial over other inorganic elements or more striking materials such as graphene."
Introduction of the OSRO procedure lead to a collaborative process in which Georgia Tech scientists performed closely with ExxonMobil researchers, including McCool and expert Harry Deckman for identifying and combat challenges of industrial processing.
Conclusion – "ExxonMobil a head in its dedication towards fundamental science,” says Mike Kerby, ExxonMobil Corporate Strategic Research scientist. “As a component of our dedication, we continue to extend our research parameter through collaborations with academic research institutions to better allow us to recognize potential breakthrough technologies to diminish the greenhouse gas emissions, boost supply of energy and realize other environmental advantages."