Efficiency of Thermal Management Using Phase-Change Material for Nonisothermal Adsorption Process

Abstract

Current energy issues have driven the development of high-throughput separation processes using solid adsorbents as an alternative to distillation. However, it is a crucial problem that the temperature increase due to the adsorption heat significantly reduces the adsorption performance because of near adiabatic operations. Herein, we discuss thermal management using phase change materials (PCMs) in such processes based on a combination of experimental and theoretical studies.Breakthrough curve measurements for n-butane adsorption on a packed bed column containing activated carbon and PCM pellets confirm the validity of our nonisothermal adsorption column model that considers the latent heat of fusion of PCMs. Then, the effects of the melting temperature and weight fraction of PCMs on adsorption performance are thoroughly investigated for an adiabatic adsorption process. Finally, we propose a simple heat balance equation for the optimum weight fraction of PCMs that maximizes the adsorption capacity of the column.

Preparation and characterization of polyethylene glycol‐based form‐stable phase change materials supported by poly (vinyl formal) foams

“…Among these candidates, polymer frameworks possess obvious advantages over others in terms of lightweight, easy processing, low cost, and excellent mechanical property. [14][15][16][17][18] Poly (vinyl alcohol) (PVA) is a typical synthetic polyhydroxy polymer with both excellent water solubility and mechanical properties. 19 PVA is easy to produce multiparous aerogels and foams, which shows good compatibility with PEG due to a large number of hydroxyl groups, making it prospective as supporting materials for PEG.…”

“…A large number of porous supporting materials, including graphene aerogels, and porous polymer frameworks, have been investigated to encapsulate PCMs. Among these candidates, polymer frameworks possess obvious advantages over others in terms of lightweight, easy processing, low cost, and excellent mechanical property 14–18 …”

Carbon-Based Monoliths with Improved Thermal and Mechanical Properties for Methane Storage

“…Contrariwise, heat has to be supplied to the adsorbent to favor the desorption of the retained molecules. Unfortunately, traditional adsorbents such as activated carbons, zeolites or metal-organic frameworks exhibit poor thermal properties, with the subsequent limitations for gas storage processes [27,28]. Thermal management can be performed either through the incorporation of heat exchanging devices into the storage vessel (e.g., honeycomb heat exchanging system) or through the modification of the adsorbent to enhance the heat conductivity [29][30][31][32][33][34][35].…”

A numerical investigation of a fixed bed CO2 adsorption process using Phase Change Materials.

“…The undesirable exothermic behavior of adsorption processes reduces the adsorption capacity (BILOÉ; GOETZ; GUILLOT, 2002) hence heat exchange systems have been developed, such as U-tubes (BASUMATARY et al, 2005;RAHMAN et al, 2011;YANG, X. D. et al, 2005) and phase change materials (PCM) (BLAZEK et al, 1990;LI;LI, 2015;RACKLEY, 2010;SAKANAKA et al, 2020) inserted in packed bed adsorption systems. The latter offers great potential because they are capable of storing substantial amounts of energy.…”

“…Although some papers have discussed the effect of packed beds with PCM alone to evaluate stability and the heat transfer between PCM and inlet fluid As integrating PCM in an adsorption bed decreases the amount of adsorbent that can be packed in the column there should be an optimal volume fraction of PCM to reach the maximum capacity of total gas adsorbed (SAKANAKA et al, 2020). The PCM acts as a heat sink, thus maximizing the heat transfer between fluid, adsorbent and PCM, which is one of the biggest challenges for the process (HORSTMEIER; GOMEZ LOPEZ; AGAR, 2016).…”