Characterisation of metal organic frameworks for adsorption cooling

Silica gel/water adsorption cooling systems suffer from size, performance and cost limitations. Therefore. there is a need for new adsorbent materials that outperform silica gel. Metal organic frameworks (MOFs) are new micro-porous materials that have extraordinary porosity and uniform structure. Due to the lack of published data that characterise MOF/water adsorption, this paper experimentally investigates the adsorption characteristics of HKUST-1 (Cu-BTC (copper benzene-1,3,5-tricarboxylate), C18H6Cu3O12) and MIL-100 (Fe-BTC (Iron 1,3,5-benzenetricarboxylate), C9H3FeO6) MOFs compared to silica gel RD-2060. The adsorption characteristics of Silica gel RD-2060, HKUST-1 and MIL-100 were determined using an advanced gravimetric dynamic vapour sorption analyser (DVS). Results showed that HKUST-1 performed better than silica gel RD-2060 with an increase of water uptake of 93.2%, which could lead to a considerable increase in refrigerant flow rate, cooling capacity and/or reducing the size of the adsorption system. However, MIL-100 MOF showed reduced water uptake comparable to silica gel RD-2060 for water chilling applications with evaporation at 5 degrees C. These results highlight the potential of using MOF materials to improve the efficiency of water adsorption cooling systems. (C) 2012 Elsevier Ltd. All rights reserved.