A process for molecular refining of crude oil developed at China’s Dalian Institute of Chemical Physics uses chemical membranes to separate crude oil at room temperature, consuming 91% less energy than conventional distillation. The work, published in National Science Review, remains at laboratory scale, and whether it can be replicated across the global petroleum industry is an open question. The potential, though, is substantial.
How Molecular Refining Crude Oil Works
Standard oil refining works by heating crude oil repeatedly, exploiting the slight differences in boiling points between its constituent chemicals to separate them. It works, but it is extraordinarily energy-hungry. According to The Open Letter, separating crude oil into fractions consumes roughly 1% of all the energy used on Earth, a figure that puts the scale of the problem in sharp relief.
The Dalian team’s approach bypasses heat entirely. Their membranes act as molecular sieves: each one is engineered to allow specific molecules to pass through while blocking others. Straight-chain and single-branched alkanes, used in producing ethylene, can fit through one sieve because they are a different size from the multi-branched alkanes and cycloalkanes used to make gasoline. The size difference the researchers had to work with was around one-one hundredth of a nanometre. Getting the two membranes right required sustained fine-tuning over that tiny margin.
When the team tested the membranes against a light sweet crude mixture containing 15 different chemicals, the process separated the oil into three groups of high-value products with a recovery rate of between 85 and 90%, the authors reported. Because nothing was boiled, vaporised or condensed, the process used 91% less energy than conventional distillation.
Corresponding authors on the study are Weishen Yang and Yujie Ban of the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and Dongdong Zhou of Sun Yat-sen University, according to EurekAlert!.
From a Single Run to 250 Hours: Early Signs of Durability
One of the persistent criticisms of membrane-based separation research is that membranes perform well in a single controlled test and then degrade. The Dalian team addressed this directly: a pilot membrane ran stably for more than 250 hours, an early indicator that the approach can hold up beyond a one-off laboratory run, as The Open Letter reported. That is a modest but concrete data point for durability, not a guarantee of industrial readiness.
The broader scientific context matters here. This work builds on a lineage of membrane research that has been developing for several years. According to the Georgia Tech Research News Center, a Georgia Tech researcher is part of an international team that has taken the membrane concept a step further, building on a 2020 paper that demonstrated membranes could separate crude oil at the molecular level. The convergence of independent research groups on this approach gives the underlying principle more credibility than any single study could on its own.
The Stakes if Refining Changes
The energy savings would matter enormously at scale. A 2021 estimate placed oil refining as the third-largest stationary contributor to global CO2 emissions, at around 1.3 gigatons of CO2 per year, reaching at its highest level about 4% of global human-related CO2 emissions. That is more than the contributions from maritime shipping or aviation. Crude oil and its refined derivatives are direct manufacturing inputs for thousands of goods, from plastics to fuels, meaning refining is not an industry that can simply be switched off or easily replaced.
Molecular refining crude oil at industrial scale would reduce both the cost and the emissions from producing gasoline, diesel and the feedstocks for plastics. That is the prize. The gap between a membrane that holds up for 250 hours in a pilot and a refinery running continuously for decades remains wide. The Dalian team has demonstrated a technically credible path; the engineering work to walk it is still ahead.
The study is published in National Science Review, with the full pilot durability data and separation results available for scrutiny by other research teams working on the same challenge.
