New Stable Reverse Osmosis Membrane for Oil Separation, Manufactured Using Interfacial Polymerization, May One Day Replace Oil Fractionation Columns in Refining and Massively Reduce Energy Use

     Engineers at MIT have developed a membrane capable of separating crude oil into fractionated components without heat. The thin polymer membrane filters the components by their molecular size and shape. This is an improved membrane that does not swell as previous versions did. According to Interesting Engineering:

“Roughly 1 percent of global energy use goes into separating crude oil into gasoline, diesel, and heating oil. That, in turn, generates about 6 percent of the world’s CO₂ emissions, mostly from the intense heat required to boil oil and separate it by boiling points.”

     The membrane was developed by repurposing a technology used in water desalination, where the use of reverse osmosis membranes has drastically cut desalination energy use.

“They replaced a flexible amide bond with a rigid imine bond, making the film more stable and hydrophobic. This allows hydrocarbons to move quickly through the membrane without causing it to swell.”

     The membrane utilizes a monomer called triptycene to help form precise, shape-persistent pores. The membranes can be manufactured by a chemical process known as interfacial polymerization, which is already used to make membranes in the desalination industry and for water purification. Thus, once the oil separation membranes are perfected and scaled, mass production should happen quickly. It is thought that these membranes will one day replace oil fractionation columns.

     According to senior author Zachary P. Smith:

“You could partition heavy and light molecules and then you could use different membranes in a cascade to purify complex mixtures to isolate the chemicals that you need.”

     It seems this technology, if perfected and scaled, could one day replace thermal distillation and streamline refineries so that they use far less energy, up to 90% less, and emit far fewer greenhouse gases. If successful, it would be a win for refinery cost reduction, a win for decarbonization, and a big win for reducing local pollution, which refineries are well known for emitting. There could be other benefits, such as lower costs to build refineries, which could lead to lower-cost oil products such as gasoline, diesel, heating fuel, jet fuel, and many other fractionated crude oil components.     

      Below are the editor's summary and abstract of the paper, published in Science. followed by an abstract of another short paper about the process included in the same issue of Science. 

   

 

References:

 

US engineers invent molecular membrane to cut crude oil emissions by 90%. Aamir Khollam. Interesting Engineering. May 22, 2025. US engineers invent molecular membrane to cut crude oil emissions by 90%

Microporous polyimine membranes for efficient separation of liquid hydrocarbon mixtures. Tae Hoon Lee, Marcel Balcik, Zain Ali, Taigyu Joo, Matthew P. Rivera, Ingo Pinnau, and Zachary P. Smith. Science. 22 May 2025. Vol 388, Issue 6749. pp. 839-844. Microporous polyimine membranes for efficient separation of liquid hydrocarbon mixtures | Science

A refinery in a thin film: A thin polymer membrane can separate industrial organic solvent mixtures through reverse osmosis. Peter M. Budd. Science. 22 May 2025. Vol 388, Issue 6749. p. 819. A refinery in a thin film | Science