CPO-27(Ni), aluminium fumarate and MIL-101(Cr) MOF materials for adsorption water desalination

Abstract

Adsorption desalination is a promising technology that has recently been investigated. Most of the reported adsorption desalination systems use silica gel as the adsorbent and despite the high stability, it suffers from limited water uptake capabilities leading to a low system performance. Metal-organic frameworks (MOFs) are porous materials with high surface area, pore size, tunable pore geometry and hence providing high adsorption capacity. Currently, limited MOF materials with high water adsorption capabilities and hydrothermal stability are commercially available. CPO-27(Ni) and aluminium fumarate are two commercially available MOFs that have a maximum water uptake of 0.47 gH2O·gads−1 and 0.53 gH2O·gad−1, respectively. Another MOF, MIL-101(Cr), exhibits superior water adsorption uptake of 1.47 gH2O·gad−1 but currently can only be produced in lab-scale.The thermodynamic cycle performance of a two beds adsorption system was evaluated using Simulink software to assess the suitability of those MOFs for adsorption desalination and their performance under different operating conditions. The CPO-27(Ni) was found to produce around 4.3m3·(ton·day)−1 at an evaporation temperature of 5°C while aluminium fumarate produced around 6m3·(ton·day)−1 at an evaporation temperature of 20°C. As for MIL-101(Cr), the water production rate at 20°C was 11m3·(ton·day)−1 highlighting the potential of this material compared to other adsorbents.