Originally published by the University of Twente
Researchers at the University of Twente have developed a groundbreaking method for purifying biogas using modified clay materials. This innovation, which forms the basis of the newly founded spinoff company CarbSorbTec, promises to make biogas upgrading more energy-efficient and economically viable.
The Challenge of Biogas Upgrading
Biogas, produced from organic waste materials, contains 40-60% methane and 30-50% CO₂. To be used as vehicle fuel or injected into the natural gas grid, the CO₂ must be removed - a process known as biogas upgrading. Current technologies like membranes and pressure swing adsorption are energy-intensive and often economically challenging for smaller facilities.
A Natural Solution
The University of Twente research team, led by Prof. Wim Brilman and Dr. Igor Sîretanu, discovered that certain clay minerals, when treated with specific cations like cesium, show remarkable selectivity for CO₂ over methane. This selectivity is 35 times higher than conventional materials.
“We were amazed by the performance of these materials,” says Dr. Niels Mendel, who conducted the research as part of his PhD. “The clay naturally prefers CO₂ molecules, and we can enhance this property through simple chemical treatment.”
Ambient Conditions, Maximum Efficiency
Unlike existing technologies that require high pressures or temperatures, the clay-based system operates at ambient conditions. This dramatically reduces energy consumption - by up to 6 times compared to membrane systems - and simplifies the equipment needed.
“The beauty of this technology is its simplicity,” explains Prof. Frieder Mugele. “We’re working with natural materials that are abundant and using straightforward processes. This translates to lower costs and easier maintenance.”
From Lab to Market
The research, published in leading scientific journals including Industrial & Engineering Chemistry Research and The Journal of Physical Chemistry C, has progressed from fundamental studies to pilot-scale testing. The formation of CarbSorbTec represents the next step: bringing this technology to commercial reality.
Environmental Impact
By making biogas upgrading more accessible and affordable, this technology could significantly accelerate the adoption of biogas as a renewable energy source. This is particularly important for smaller facilities - such as farm digesters and local wastewater treatment plants - that have been unable to justify the cost of conventional upgrading equipment.
“Every ton of CO₂ we capture from biogas is a ton that doesn’t enter the atmosphere,” notes Prof. Brilman. “But just as importantly, we’re helping to make renewable energy more economically attractive. That’s how we’ll achieve real, lasting change.”
Recognition and Support
The technology has received support from Novel-T, the University of Twente’s innovation and valorization center, as well as recognition from various innovation programs. This support has been instrumental in transitioning from academic research to commercial development.
For more information about this research, contact the University of Twente press office or visit CarbSorbTec’s website.