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Nanofiber mats produced by electrospinning, with the advantages of specific surface area, porosity and chemical tenability, are an ideal support material for deposition of metal$-$organic framework (MOF) crystals. In this study, four types of MOFs (MIL-53(Al), ZIF-8, UiO-66-NH₂ and NH₂-MIL-125(Ti)) were deposited on polydopamine (PDA)-modified electrospun polyvinyl alcohol (PVA)/SiO₂ organic$-$inorganic hybrid nanofiber mats by bulky synthesis. Because of the formation of Si–O–C–O–Si bridges between PVA chains and silica network, electrospun PVA/SiO₂ organic$-$inorganic hybrid nanofiber mats are quite stable in water or organic solvents and at high temperature are suitable as supports for MOFs deposition. The PDA layer, which exhibits a powerful adhesive ability to attach foreign objects, can effectively improve growth of MOFs on the surface of PVA/SiO₂ nanofiber mats. The obtained MOF composites combining the unique properties of electrospun nanofibers mats and MOFs particles become flexible and tailorable, greatly expanding the application range of MOFs materials. The synthesized MOF composites were used to adsorb chloramphenicol (CAP) in water. It was found that the four MOF composites could remove CAP from water effectively and MIL-53(Al) composite had the highest adsorption capacity due to the higher specific surface area.

This study aimed at analyzing different operation strategies to improve the performance of a new type adsorption chiller employing a novel composite adsorbent, silica gel impregnated with lithium chloride, paired with methanol as the adsorbate. The chiller's experimental test results showed an average Specific Cooling Power (SCP) and Coefficient of Performance (COP) of 286 W/kg and 0.48, respectively. This was when the average hot water inlet temperature, cooling water inlet temperature, and chilled water inlet temperature were 83°C, 26°C and 15°C, respectively. In addition, the corresponding mass flow rates were 0.22, 0.39 and 0.09 kg/s, respectively. Despite the fact that the average SCP and COP, were rather satisfactory, analysis of experimental results conducted with different cycle times, inlet hot water temperatures, and hot water flow rates showed that a much better performance could be achieved. Experimental results indicated the following: (1) the COP increased while the SCP decreased with increased cycle time, (2) both the COP and the SCP increased with increase in heat and mass recovery time to an optimal time then started to decrease as heat and mass recovery time increased beyond the optimal time, (3) both the cooling power and COP generally increased with increase in inlet hot water temperature at a relatively higher value from 60°C to about 90°C beyond which the incremental value started diminishing, and, (4) increase in mass flow rates produced higher cooling power with decreased COP while decrease in mass flow rates of hot water produced lower cooling power with increased COP. This paper therefore recommends an adsorption/desorption time, heat and mass recovery time, inlet hot water temperature, and hot water mass flow rate of 780 s, 60 s, 83°C, and 0.22 kg/s as appropriate to give the best chiller performance for refrigeration.

Researchers proved that, heat powered adsorption refrigeration technology is very effective methods for reutilization of low-grade thermal energy such as industrial waste heat, solar energy, and exhaust gases from engines. But to make it commercially competitive with the well-known vapor compression and absorption refrigeration system, the processes require high rates of heat and mass transfer characteristic between adsorbate and adsorbent as well as externally supplied heat exchanging fluid. This paper reviews various techniques that have been developed and applied to enhance the heat transfer and mass transfer in adsorber beds, and also discuss their effects of the performance on adsorption system. A comprehensive literature review has been conducted and it was concluded that this technology, although attractive, has limitations regarding its heat and mass transfer performance that seem difficult to overcome. Therefore, more researches are required to improve heat and mass transfer performance and sustainability of basic adsorption cycles.