Contact Angle and Condensation of a CO2 Droplet on a Solid Surface

Abstract

Anthropogenic release of carbon dioxide (CO2) is a major contribution to manmade increase in global warming. Carbon capture and storage (CCS) is a necessary technology for lowering CO2 emissions to an acceptable level that limits global warming to below 2 °C. Liquefaction of CO2 is a key process both in capture technologies and in conditioning before ship transport. The efficiency of this process can be remarkably enhanced by promoting dropwise CO2 condensation on cooling surfaces, yet this remains largely unexplored. Here, using molecular dynamics (MD) simulations, we report for the first time the contact angle and condensation behavior of CO2 droplets on a smooth solid surface. The contact angle of the condensed CO2 droplet is greatly dependent on the CO2–solid characteristic interaction energy, but this does not hold true for the sum of condensed molecules. In contrast, the sum of condensed molecules for the filmwise condensation regime increases monotonically at first, but then remains constant as the...