The oil giant, working with scientists at the Georgia Institute of Technology, say if brought to industrial scale, the technology could reduce industry’s global annual carbon dioxide emissions by up to 45 million tons and also reduce global energy costs used to make plastics by up to $2 billion a year.
Results of the research were published in the journal Science.
Exxon told Reuters it was too early to say when the new technology could be brought to market.
The new process uses reverse osmosis to separate para-xylene, a chemical building block for polyester and plastics, from complex hydrocarbon mixtures.
The conventional commercial-scale process uses energy and heat to separate those molecules. Globally, the amount of energy used in this process for aromatics is equal to about 20 average-sized power plants.
Reverse osmosis is already widely used to desalinate seawater, consuming a fraction of the energy required by thermally driven processes. The researchers say this new reverse osmosis process is the first use of reverse osmosis with carbon membranes to separate liquid hydrocarbons.
The ExxonMobil and Georgia Tech team first 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.
ExxonMobil say the carbon-based membrane is 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, the company says it has potential for commercialization and integration into industrial chemical separation processes.
The technology still faces challenges before it can be considered for commercialization and use at an industrial scale. The membranes used in the process will need to be tested under more challenging conditions. The researchers must also learn to make the material consistently and demonstrate that it can withstand long-term industrial use.
Chemical plants account for about 8 percent of global energy demand and about 15 percent of the projected growth in demand to 2040.
Exxon also recently developed a technology to produce ethylene, an important chemical in plastics, directly from crude oil. A report by IHS says this development could potentially save refiners as much as $200-per-ton of ethylene produced.