Efficient Liquefaction of Carbon Dioxide on Superlyophobic Surfaces

Abstract

Liquefaction of CO2 is a necessary step in several parts of the carbon capture, transport and storage (CCS) chain, e.g. for processing for ship transport. By increasing the efficiency of condensation, a lower energy consumption is achieved and hence, costs are reduced for CCS. Increased condensation efficiency can be achieved by inducing dropwise condensation instead of the conventional filmwise condensation. This switch in condensation mode is caused by alterations of the surface on which the condensation occurs and can be achieved by structuring the surface on the nanoscale and coating with low surface energy chemicals. In this work we have built a new experimental setup to investigate the condensation process. The setup consists of a highly instrumented pressure chamber that can operate up to 25 bar with a high purity CO2 atmosphere, and a condensation surface that can be cooled to -55ºC. Visual observation is performed through a sight glass in the pressure vessel using a high-speed camera. The process of CO2 condensation is visually monitored and the contact angle, contact angle hysteresis, and mode of condensation on different surfaces can be found.