Experimental study of carbon dioxide desublimation and sublimation process on low temperature surface

Abstract

Cryogenic carbon dioxide capture by the desublimation method has the advantage of being contamination free and energy efficient under high concentration. Due to the difficulty of collecting solid CO2 after desublimation, this method has not been applied. In this paper, a visual experimental setup for carbon dioxide desublimation and sublimation on a low temperature surface is introduced in detail. The core part of the experimental set-up is a visual tube-in-tube counterflow heat exchanger consisting of a Pyrex glass tube with a larger diameter and a stainless-steel tube with a smaller diameter. The crystal growth and dissipation occur on the precooled outer surface of the inner tube, which is recorded by a camera. When carbon dioxide desublimates under different working conditions, such as temperature and supersaturation, the growth shape and growth rate of the solid are different. The thermal properties of the solid such as porosity, thermal conductivity and density are also different, leading to variations in the sublimation process and speed. Three distinct sublimation processes are discussed in this paper to provide guidance on the actual carbon capture process.