Performance improvement of vacuum swing adsorption processes for CO2 removal with integrated phase change material

The present work describes an optimised process model for CO2-adsorption via vacuum swing adsorption (VSA). The process parameters in cyclic steady-state are compared for three different adsorbents, namely 13X zeolite, an amine functionalised activated carbon and a commercial amine adsorbent, Lewatit VP OC 1065. During the VSA process, strong temperature variations arise between the adsorption and desorption steps, which diminish the adsorbent capacity. To suppress these temperature fluctuations, a phase change material (PCM) may be incorporated as a latent heat storage medium. The cyclic steady-state results indicate that a much higher efficiency and improved performance result from integrating the adsorptive and thermal functionalities in hybrid adsorbent-PCM particles. An increase in product purity of 20% up to 92% and 50% extensions of cycle times at constant recovery rates are possible. The specific power requirement decreases by about 80%. (C) 2016 Elsevier Ltd. All rights reserved.