Abstract
Cryogenic carbon capture from natural gas at high pressures requires accurate process synthesis and determination of process parameters due to the presence of solid-vapor and vapor-liquid-solid equilibria. At high pressures, the higher liquid formation not only causes operational problems, but also induces hydrocarbon losses in cryogenic packed beds. The present study proposes a novel multiple cryogenic desublimation based pipeline network with its sections at different cryogenic pressures and temperature profiles to enhance the separation. The experimental study explores the simultaneous separation of water and carbon dioxide from ternary feed gas mixture (CH4-CO2-H2O) by using multiple counter current cryogenic desublimation beds.
A novel simulation strategy using multiple equilibrium temperature (MET) concept is also introduced for simulation studies. Simulation studies were subsequently conducted for both atmospheric and high cryogenic bed pressures and compared with experimental measurements. The effect of ambient humidity on dehydration was also investigated experimentally and it was observed that the humidity has significant effects on dehydration due to back diffusion. The effect of some important parameters like bed length, feed gas pressures, bed temperatures, feed flow rates and feed gas pressures for separation were investigated. Experimental investigation was also conducted to quantify liquid formation and vapor-solid equilibrium at high pressures. The experimental results of desublimation based cryogenic pipeline network showed promising potential for industrial exploitation. (C) 2016 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.