Self-Forming Nanoscale Channels in Inexpensive Membrane Could Slash Oil Refinery Energy Use

Researchers have developed a remarkably straightforward method to separate crude oil without applying heat, potentially transforming one of the world’s most energy-intensive industrial processes. The breakthrough centers on an inexpensive membrane that could dramatically lower the energy demands of oil refining while reducing operating costs and carbon emissions.

The international research effort was led by Professor Dong-Yeun Koh at the Korea Advanced Institute of Science and Technology (KAIST), working alongside Professor Ryan Lively’s team at Georgia Tech. KAIST President Kwang Hyung Lee announced that the team successfully demonstrated a membrane capable of separating crude oil at room temperature. The findings appeared in Nature, one of the world’s premier scientific journals.

Crude oil serves as the foundation for far more than gasoline and transportation fuels. It also provides the raw materials for plastics, packaging, clothing, and countless everyday products. Because refining costs influence the price of these goods, improving efficiency could yield broad economic and environmental benefits.

Why Conventional Crude Oil Refining Demands So Much Energy

For over a century, oil refineries have depended primarily on distillation to separate crude oil into useful components. This method involves heating oil above 350 °C, vaporizing portions of it, and then cooling the vapors to collect different fractions.

The process consumes vast amounts of energy. Globally, crude oil distillation uses roughly 1,100 terawatt-hours (TWh) per year—equivalent to the combined annual electricity output of about 130 nuclear power plants, each operating at approximately one gigawatt.

This enormous energy requirement makes distillation a major driver of fuel consumption and greenhouse gas emissions in the refining sector. At the same time, mounting economic pressures across global petrochemical markets have intensified interest in more efficient oil-separation technologies.

Membranes have emerged as a promising alternative because they can separate substances without the extreme temperatures required by conventional distillation. Yet previous designs have encountered significant challenges.

Researchers traditionally assumed that effective molecular separation requires a membrane coated with an extremely thin, specialized layer. While such coatings can deliver the necessary precision, they are costly to manufacture and prone to defects at industrial scale. These drawbacks have hindered widespread adoption.

A Surprising Discovery Turns Clogged Filters Into an Advantage

The KAIST and Georgia Tech researchers took a different approach. Instead of applying a complex coating, they used an uncoated membrane made from porous polyacrylonitrile (PAN), an inexpensive, chemically stable polymer already widely employed as a support material in industrial filtration.

What occurred when crude oil passed through the membrane was unexpected.

As oil flowed through its pores, heavier hydrocarbon molecules accumulated along the inner walls. This buildup gradually narrowed the openings, creating exceptionally narrow channels measuring less than 2 nanometers across.

In effect, the crude oil helped generate the microscopic pathways needed to separate its own components.

These naturally formed channels allowed lighter oil fractions—including naphtha, gasoline, and kerosene—to pass through quickly while restricting the movement of heavier substances through the membrane.

The discovery was particularly surprising because membrane fouling—the accumulation of material inside pores—is normally regarded as a serious flaw. Fouling typically degrades filtration performance and requires cleaning or replacement. Here, however, the same phenomenon made the membrane highly effective at separating different molecules.

The results were notable. The uncoated PAN membrane achieved crude oil permeation rates roughly 23 times higher than previous leading crude oil separation membranes. It also maintained stable performance for 28 consecutive days.

Professor Ryan Lively of Georgia Tech commented: “One of the key challenges facing membrane systems for crude oil separation has been low unit productivity. PAN membranes with this surprising separation mechanism dramatically increase membrane unit productivity, to the point where industry should seriously consider adopting the technology.”

New Membrane Could Cut Oil Refining Energy Use by Nearly a Third

One of the technology’s greatest advantages is that refineries would not necessarily need to replace their existing equipment to use it.

The membrane could instead be installed as a modular filtration system that treats crude oil before it enters conventional distillation equipment. This would reduce the workload during heating and separation while allowing facilities to retain much of their current infrastructure.

Computer simulations suggest that integrating the membrane into refining could deliver substantial improvements. Energy consumption could drop by 31.6%, while carbon dioxide emissions could fall by 37.6%. The same projections estimated a 20.7% reduction in cooling water consumption and a 36% decrease in operating costs.

The potential environmental benefits could be considerable if adopted widely.

Researchers estimate that implementing the system across Korea’s refining and petrochemical industries could prevent approximately 10 million tonnes of greenhouse gas emissions annually—roughly equivalent to the yearly emissions of four million internal-combustion-engine vehicles.

These savings are projections based on process simulations rather than demonstrated reductions at operating refineries. Still, the findings indicate that membrane filtration could become a practical way to improve the efficiency of existing facilities.

Applications Beyond Oil Refining

Although crude oil separation was the primary focus, the same technology could eventually prove useful in several other industries.

One potential application involves treating pyrolysis oil produced when waste plastics are broken down for recycling. The membranes could also help recover solvents used in battery manufacturing, purify pharmaceutical compounds, and improve biofuel production.

The broader opportunity lies in using complex liquid mixtures to help form the tiny filtration channels needed to separate their components. This approach could provide a more affordable and versatile alternative to conventional membranes requiring precisely manufactured surface coatings.

Professor Dong-Yeun Koh of KAIST said, “This study reveals a new scientific principle in which a membrane interacts with a complex mixture and spontaneously forms its own separation channels. Working with real crude oil supplied by HD Hyundai Oilbank allowed us to validate the technology under industrially relevant conditions.”

The use of actual crude oil was crucial because it allowed the team to examine how the membrane performed with the complicated hydrocarbon mixture found in industrial feedstocks.

Before broader deployment, the researchers plan to scale up membrane production and establish reliability during extended operation.

Professor Jae W. Lee of KAIST, a co-corresponding author, added, “By advancing large-area membrane modularization and long-term operational reliability, we hope to broaden the adoption of membrane-based processes throughout the refining and petrochemical industries.”

Dr. Jihoon Choi and Dr. Hyeokjun Seo of KAIST, the study’s co-first authors, said, “Our goal is to precisely control this spontaneous pore-constriction phenomenon and develop it into a membrane platform applicable across the entire refining process. We also aim to expand the technology to plastic recycling, biofuel purification, and other sustainable chemical processes that support carbon neutrality.”

The research received support from Korea’s Ministry of Science and ICT through the Basic Research Program for Outstanding Early-Career Researchers and the Engineering Research Center (ERC) Program.

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