CEAT disciplines combine expertise to develop way to separate nitrogen from natural gas

Thursday, January 8, 2026

Media Contact: Tanner Holubar | Communications Specialist | 405-744-2065 | tanner.holubar@okstate.edu

Interdisciplinary engineering research in the College of Engineering, Architecture and Technology at Oklahoma State University is pushing the boundaries of engineering through a grand challenge: separating nitrogen from natural gas.

Separating nitrogen has been an issue plaguing the natural gas industry for decades, and the researchers are meeting this challenge head-on. This research is in collaboration with SK E&S Americas, Inc., through a $165,529 grant.

Under the oversight of Dr. Prem Bikkina of the School of Chemical Engineering and Dr. Kaan Kalkan of the School of Mechanical and Aerospace Engineering, the research team seeks to develop a novel concept to remove nitrogen from natural gas, primarily methane.

It has been a challenging issue in the oil and gas industry because many wells produce natural gas with too much nitrogen. The existing technology for removing nitrogen is large, expensive and only practical at large plants.

The method produced by Bikkina and Kalkan’s team uses a different concept to capture nitrogen. Nitrogen bubbles form more easily at specific liquid/solid interfaces than methane. By focusing on the “wettability-driven” formation of bubbles, the team can separate the gases while they are in the vapor phase from the dissolved state. This method opens the door to a simpler and cheaper alternative to conventional technologies.

“A cost-effective and scalable method to separate N₂ from CH₄ could significantly expand the marketability of stranded or sub-quality natural gas reserves,” Bikkina said. “This would not only improve the economic feasibility of many domestic and international gas plays but also support global energy transition goals by maximizing the use of existing cleaner-burning resources while minimizing waste.”

“The collaboration aims to integrate our experimental expertise with SK’s global energy initiatives, aligning scientific innovation with real-world application needs,” Bikkina said.

Some of the main drawbacks of current technology highlight the need for new, low-energy separation techniques tailored to specific operational uses. Some of the main disadvantages include:

• Cryogenic distillation, while highly effective, is energy-intensive, capital-heavy and only economical at large LNG-scale operations.
• Membranes offer compactness and lower capital cost, but current materials fall well short of the N₂/CH₄ selectivity (~17) needed for pipeline-grade separation.
• Adsorption systems are energetically favorable but require large volumes because CH₄ adsorbs more readily than N₂.
• Absorption lacks practical solvents with strong N₂ selectivity, primarily due to nitrogen’s chemical inertness.

The team will conduct fundamental experiments to determine which conditions cause nitrogen and natural gas bubbles to form.

“We are exploring both surface properties (e.g., wettability) and fluid properties using water and other solvents — including ionic liquids,” Bikkina said. “In future stages, we plan in situ gas composition measurements using confocal Raman spectroscopy and microneedle gas collection, followed by GC or MS analysis, to confirm selective nucleation at the molecular level.”

Engineering professions coming together

This research brings expertise from CHE and MAE together to bridge the gap between academic innovation and industrial necessity.

The CHE portion of the team provides expertise in thermodynamics, interfacial science and phase behavior. The MAE cohort contributes expertise in advanced optical diagnostics through Raman spectroscopy.

“This interdisciplinary framework ensures that both fundamental material behavior and real-time analytical techniques are applied to solve an efficient separation challenge,” Bikkina said.

This research is an excellent opportunity for graduate students in CEAT to gain practical experience researching a defined industry need. CHE graduate students will lead experiments on bubble nucleation, surface preparation, and gas collection techniques. One of Kalkan’s graduate research assistants will focus on confocal Raman spectroscopy.

It is a unique research opportunity to participate in fundamental research while working to solve a problem that has long plagued the natural gas industry.

This project is true to OSU’s land-grant mission of advancing scientific knowledge to benefit society. It is also an example of CEAT researchers setting out to develop ways to address long-standing issues caused by technological and scientific limitations. This research team is answering the call to overcome these limitations through innovation in the face of a challenge.