Scientists and researchers have long been in a race to reduce the price of carbon capture. Chemical engineers at EPFL seem to have succeeded in the race by managing to find a way of cutting the price per ton of captured CO2. They have developed a graphene filter for carbon capture that surpasses the efficiency of commercial capture technologies. The filter could cut the cost of carbon capture down to $30 per ton of carbon dioxide.
One of the main problems for carbon capture science is separating the extracted CO2 from other gases in the mix. The waste CO2 is not emitted pure but is mixed with nitrogen and other gases. Therefore, it is quite energy demanding and thus pricier to extract it from industrial emissions.
Scientists have been trying to develop an energy-efficient carbon dioxide-filter. This technology is known as a “membrane” and is capable of separating the CO2 from the gas mix. The pure carbon dioxide can then be either stored or utilized into various products.
Carbon Capture Price Drop Explained
Professor Kumar Varoon Agrawal at EPFL’s School of Basic Sciences has led a team of chemical engineers who developed the world’s thinnest filter from graphene. The filter doesn’t only separate CO2 from other gases but it does so with an efficiency and speed that surpasses most current filters. Their work is published in Science Advances.
Mr Agrawal explained their approach, saying: “We made carbon dioxide-sized holes in graphene, which allowed carbon dioxide to flow through while blocking other gases such as nitrogen, which are larger than carbon dioxide.”
Filters used commercially at the moment are required to exceed 1000 gas permeation units (GPUs), while their carbon dioxide separation factor must be above 20. The one that the EPFL scientists developed shows more than ten times higher carbon dioxide permeance at 11,800 GPUs. Its separation factor is at 22.5. All that results in a record-high CO2-capture performance.
The team estimated that the technology improvement will drop the carbon capture price close to $30 per ton of CO2. In comparison, the cost right now is two-to-four times higher.
Agrawal’s team is working on developing a pilot plant demonstrator to capture 10 kg carbon dioxide per day in Switzerland. The project is funded by the Swiss government and the industry.
Carbon capture technology has shown potential in the way of cost reduction and efficiency improvements. The properties of new and known materials are constantly researched by scientists to increase carbon capture performance and if this potential breakthrough is anything to go by, then we could see carbun capture costs drop dramatically in the near future.
- S. Huang, S. Li, L. F. Villalobos et al. Millisecond lattice gasification for high-density carbon dioxide- and O2-sieving nanopores in single-layer graphene. Science Advances 2021, 7, eabf0116, 24 February 2021. DOI: 10.1126/sciadv.abf0116