"Petroleum Refining Without Boiling"... Technology Developed to Reduce Energy Costs to One-Tenth

KAIST Research Team Publishes Paper in 'Advanced Science'
Development of Liquid Organic Matter Direct Separation Organic Solvent Forward Osmosis System

[Asia Economy Reporter Kim Bong-su] A technology that can save energy by one-tenth compared to existing methods when separating substances in processes such as refining, pharmaceuticals, and semiconductors has been developed.

The Korea Advanced Institute of Science and Technology (KAIST) announced on the 12th that a research team led by Professor Ko Dong-yeon of the Department of Biological and Chemical Engineering developed an organic solvent forward osmosis system capable of directly separating liquid organic substances with size differences of less than 0.1 nanometers (nm) at room temperature.

Large-scale separation processes of liquid mixtures mainly use distillation methods that rely on differences in boiling points of substances. The problem is that enormous amounts of energy are consumed worldwide during this process. In particular, liquid hydrocarbons, which form the basis of the petrochemical industry, are essential for developing materials closely related to daily life such as fibers and plastics. Therefore, a new future-oriented paradigm is needed to separate these substances through low-energy, low-carbon processes.

The ultrafine porous carbon separation membrane developed by the research team is attracting attention as a technology that can solve the above energy issues. It can continuously separate liquid hydrocarbons by size and shape at room temperature. The organic solvent forward osmosis method developed by the team uses a carbon separation membrane with precisely designed pore sizes and structures. This is an energy-efficient technique where separation of hydrocarbon chemical species occurs based on natural concentration gradients and chemical potentials without external power sources, according to differences in size and shape. Notably, the energy consumption is only one-tenth that of conventional distillation methods. Depending on the pore size design of the membrane material, it can be applied in various fields such as petrochemicals, refining, pharmaceuticals, and semiconductor processes, maximizing energy efficiency across industries while simultaneously reducing carbon emissions, making it a groundbreaking technology.

In particular, the research team demonstrated that mixtures of hexane isomers with different sizes and shapes can be easily separated by shape differences at room temperature. The carbon separation membrane has ultrafine pores in a hard slit-like structure smaller than 0.7 nanometers (nm), and by controlling molecular diffusion in such small nanoscale spaces, it can precisely filter molecules with size differences of less than 0.1 nanometers (nm). The carbon separation membrane used in this study has a hollow fiber shape, similar to a hollow thread. Its industrial applicability and ripple effects are expected to be significant. Hollow fiber membranes are very easy to mass-produce at low cost and have tens of times larger surface area compared to conventional flat membranes, making them a promising material as next-generation membranes.

The research team succeeded in separating liquid molecules smaller than 0.1 nanometers (nm) by size and shape using membranes, which was previously impossible, opening a new chapter for low-energy, low-carbon separation processes. This new method of separating and refining hydrocarbon molecules, which are raw materials for numerous substances, at low cost and with low carbon emissions is a hot topic in the chemical industry.

Professor Ko said, "Korea imports crude oil and relies on various integrated technologies to separate and refine it to create various high value-added products. Dramatic cost reductions in this area directly strengthen the global competitiveness of the petrochemical industry. We especially expect this technology to be widely used in pharmaceutical fields and semiconductor chemical processes where solvent usage is high," he explained.

This research was published online in the international academic journal Advanced Science and was selected as a back cover paper.