The ionic solution to pollution

Author: John Monczunski

The best way to reduce greenhouse gases in the atmosphere is to stop burning fossil fuels. Realistically, that won’t happen soon. Therefore, a bridge strategy is needed until clean, renewable energy becomes the dominant form in the world. That’s where CO2 capture and ionic liquids may come in, says Edward Maginn.

The chemical and biomolecular engineering professor and his ND colleagues, Joan Brennecke and William Schneider, have demonstrated that the unusual fluids may offer a promising solution to the problem.

Ionic liquids, also known as molten salts, have a high affinity for carbon dioxide and remain fluid at high temperatures without vaporizing, Maginn explains. Those qualities make them ideal for removing combustion CO2 from power plant flue gases. In theory, once the carbon dioxide is removed from combustion gas, it could be pumped deep into the earth where it would remain safely sequestered, thus lowering greenhouse gas emissions in the atmosphere.

Using a molecular engineering approach, the ND researchers have been able to triple the carbon dioxide solubility of the fluids. Maginn’s group specializes in atomistic modeling of materials to predict how chemical structure changes properties. Schneider’s team calculates such things as binding strength to optimize the material, while Brennecke’s lab synthesizes and experimentally tests the fine-tuned ionic liquids.

Their early results have been so promising that the Department of Energy authorized taking the work to the next level. The ND researchers have teamed with DTE, the Detroit power company; Babcock & Wilcox, a power plant construction firm; and Air Products, a gas separation firm, to further investigate the system’s feasibility.

John Monczunski is an associate editor of this magazine.