Scientists from oil and chemical giant ExxonMobil Corp. and the Georgia Institute of Technology have developed a potential breakthrough to reducing the amount of energy and emissions associated with manufacturing plastics and cut costs by up to $2 billion annually.
Results of the research were published Aug. 18 in the peer-reviewed journal Science, and ExxonMobil said that if brought to an industrial scale, the new technology could slash industry's global annual carbon dioxide emissions by up to 45 million tons, or the equivalent of around 5 million households.
The project focused on replacing the existing energy-and-heat method to separate molecules with a molecular-level filter and a form of reverse osmosis to separate para-xylene, a building block for polyester, from complex hydrocarbon mixtures.
“If advanced to commercial-scale application, this technology could significantly reduce the amount of greenhouse gas emissions associated with chemical manufacturing,” said Vijay Swarup, vice president of research and development at ExxonMobil Research and Engineering Co.
ExxonMobil said the research “successfully demonstrated that para-xylene can be separated from like chemical compounds known as aromatics by pressing them through a membrane that acts as a high-tech sieve, similar to a filter with microscopic holes.”
Initially the ExxonMobil and Georgia Tech team developed a new carbon-based membrane that can separate molecules as small as a nanometer. The membrane was then incorporated into a new organic solvent reverse osmosis process, during which aromatics were pressed through the membrane, separating out para-xylene.
"In effect, we'd be using a filter with microscopic holes to do what an enormous amount of heat and energy currently do in a chemical process similar to that found in oil refining,” said Mike Kerby, corporate strategic research manager at ExxonMobil.
Researchers said the carbon-based membrane was about 50 times more energy efficient than the current state-of-the-art membrane separation technology. Because the new membrane is made from a commercially-available polymer, ExxonMobil said it believed it had the potential for commercialization and integration into industrial chemical separation processes.