Adsorbent Coatings for Adsorption Heat Transformation: From Synthesis to Application

Abstract

In recent years, growing energy demands and environmental pollution caused by the extensive use of fossil fuels have inspired considerable research interest in adsorptive heat transformation (AHT). This technology offers effective utilization of low-grade solar or waste thermal energy for cooling and heating with low environmental impact. Increasing the AHT power is a keystone for further development and dissemination of this emerging technology. The AHT power is mainly determined by ad/desorption dynamics, which is significantly hindered by slow heat transfer between the adsorbent and heat exchanger. Shaping the adsorbent bed as a coating on the heat exchanger surface is considered an effective route to enhance heat transfer and increase the AHT power. In this review, the technology of adsorbent coating for AHT is comprehensively surveyed, including coating synthesis, adsorption dynamics, and use in real AHT devices. The advantages of the coated bed configuration are considered, and its challenges are outlined. Finally, recommendations for better organization of the coating’s structure for rational control of the relative contributions of heat and mass transfer are considered.

Water Adsorption Dynamics on Metal–Organic Framework MOF-801: Comparative Study of Loose and Glued Grains, and Coatings

“…10) adsorptiondesorption cycles. To synthesize the MOF-801 coating (Figure 1b), the slurry consisting of the known amount of MOF-801 powder, binder, and water was applied to pretreated Al foil using the drop-coating method (Figure S2 in the Supplementary Materials) [7]. The total mass of the slurry deposited on the foil was calculated as…”

“…In this vein, the optimization of the Ad-HEx 2 of 16 configuration is becoming a hot topic of research related to AHTS technology [4][5][6]. Nowadays, two basic Ad-HEx configurations are widely used, namely, the loose adsorbent grains loaded between the HEx fins and the thin adsorbent coating on the HEx surface [7,8]. Due to the large porosity of the loose grains configuration and high contact resistance, the poor heat transfer between the adsorbent bed and HEx surface and inside the bed is considered to be the factor controlling the adsorption rate and reducing the SP [9][10][11].…”

The Preparation and Contact Drying Performance of Encapsulated Microspherical Composite Sorbents Based on Fly Ash Cenospheres

“…Sorption technologies are a key separation tool in various industries-chemical, biological, pharmaceutical, energy, etc.-providing the quality of raw materials, products, and the productivity of processes in general [1][2][3]. To date, the main applications of adsorbents are separation of gas and liquid mixtures [4,5], catalysis and ion exchange [3], heat conversion/storage/amplification [6][7][8], water harvesting from atmospheric air [9], recuperation of heat and moisture in ventilation systems [10], active heat insulation [11], and air conditioning [12]. Such diverse applications often require materials with adsorption properties that can differ considerably for different applications.…”