Scientists from the UK and New Zealand have developed a groundbreaking membrane that can capture carbon dioxide (CO2) from the atmosphere, as published in a study.
Carbon dioxide is a major contributor to global warming, with annual emissions reaching around 40 billion tons. However, its concentration in the atmosphere is only about 0.04%, making it challenging and energy-intensive to extract. The low CO2 concentration results in slow chemical reactions, requiring significant energy costs for extraction.
The researchers have successfully overcome these obstacles by utilizing a new membrane that leverages natural humidity differences as a driving force. This innovative solution not only reduces energy consumption but also accelerates the transfer of carbon dioxide through the membrane, with water playing a crucial role in the process.
The technology is particularly essential for capturing carbon dioxide emissions from mobile and distributed sources that are difficult to decarbonize using other methods. The synthetic membrane can capture carbon dioxide from the air without relying on traditional energy sources like heat or pressure, functioning similarly to a water wheel in a flour mill but “pumping” carbon dioxide from the air.
The synthetic membrane, based on molten salt with aluminum oxide (AL2O3) and a carrier with a triple eutectic mixture of molten carbonates ((Li/Na/K) 2CO3) in artificial pores drilled by a laser, uses the difference in humidity (between hot and dry air) to extract CO2 from one airflow to another against its concentration gradient.
Separation processes are crucial in various industries, from food and drugs to fuel and batteries, and play a significant role in waste reduction and environmental protection, including direct carbon dioxide capture. Using x-ray microtomography, researchers were able to analyze the membrane’s structure and compare its efficiency with other modern membranes. Molecular-level modeling helped identify the carriers inside the membrane that transport both carbon dioxide and water simultaneously.