Roadmap Towards Clean Coal Technology for South Africa

We report on a novel approach to liquid amine-based CO₂ capture, motivated by liquid infused surfaces (LIS) technology. An LIS is a chemically functionalized micro-textured solid substrate that is able to immobilize a thin layer of liquid on itself. LIS has been used for applications in bio- and hydrocarbon fouling prevention, corrosion inhibition, and anti-icing surfaces. While applications utilizing the non-reactive impregnating liquid of an LIS to isolate or protect a solid surface have proven fruitful, exploitation of the immobilized liquid of LIS itself as a reactive medium has not been considered yet. Since the impregnating liquid is strongly held by capillary forces on the solid surface, it can be formed and structured by controlling and shaping the underlying substrate, enabling a new class of technological opportunities. Generating an LIS using a reactive liquid on a textured and chemically-modified continuum solid structure with high A/V can shape a liquid with a similarly large A/V. We refer to this class of LIS as a “solid with infused reactive liquid” (SWIRL).

We present the fabrication and demonstration of SWIRL-amine (amine is the reactive liquid). As opposed to the currently practiced aqueous amine technology, high amine-CO₂ interfacial area in SWIRL is generated without mechanical mixing, allowing the use of neat liquid amine with high CO₂ capacity at elevated temperatures close to the flue gas temperature. In addition, the high A/V SWIRL property promises much smaller-scale infrastructure.