Experimental investigation of metal organic frameworks characteristics for water adsorption chillers

Abstract

Adsorption cooling is a promising technology that can effectively utilise waste heat from many industrial processes for refrigeration and air conditioning. The choice of the adsorbent in this technology is vital to produce efficient and compact systems. Metal organic frameworks are new microporous materials with exceptionally high porosity and large surface area that can be used as adsorbents. This article experimentally investigates the characteristics of seven metal organic frameworks in terms of water adsorptivity compared to silica gel RD-2060. The adsorption characteristics were determined using an advanced gravimetric dynamic vapour sorption test facility. Results revealed that HKUST-1produced the highest water adsorption uptake with up to 95.7% increase compared to silica gel RD-2060 but showed deterioration in water adsorptivity with time. Throughout the temperature range tested, Fe-BTC has shown little hysteresis and produced up to 26.8% higher maximum water uptake value than silica gel RD-2060. These results highlight the potential of using certain metal organic frameworks materials to improve the efficiency of adsorption cooling systems; however, the thermal instability of some metal organic frameworks remains an issue that needs to be resolved.