A novel method to improve the gas storage capacity of ZIF-8
2012; Royal Society of Chemistry; Volume: 22; Issue: 24 Linguagem: Inglês
10.1039/c2jm31541f
ISSN1364-5501
AutoresLiang Mu, Bei Liu, Huang Liu, Yuntao Yang, Chang‐Yu Sun, Guangjin Chen,
Tópico(s)Enhanced Oil Recovery Techniques
ResumoIn this work a novel method for enhancing the gas storage capacity of metal–organic frameworks (MOFs), i.e. saturating the MOF with a suitable quantity of water and forming hydrates in it, was proposed. Commercialized ZIF-8 was adopted as it is very stable under an atmosphere of water. The adsorption and hydrate formation behaviors of methane in wet ZIF-8 with five different water contents (0.0%, 16.3%, 27.7%, 30.6%, and 35.1%, mass percentages) were investigated under hydrate formation conditions and the storage capacities of both ZIF-8 frameworks and ZIF-8 particle beds were determined. Our results show that hydrates can form in wet ZIF-8 pores and thus increase the overall storage capacities of both ZIF-8 frameworks and ZIF-8 particle beds remarkably. The contribution of hydrates to the total gas uptake of a ZIF-8 framework can be as high as 45%. Compared with dry ZIF-8 frameworks, the net storage capacity of the wet analogue with a water content of 35.1% increases from 5.954 to 9.304 mmol g−1 at 269.15 K and 2.85 MPa, in other words, raised by more than 56%. The ideal volume storage capacity of the wet ZIF-8 framework can achieve more than 190 V/V at 3.0 MPa or so, 7% higher than the DOE target (180 V/V) for methane storage. In addition, our SEM measurements and XRD analysis demonstrate that ZIF-8 is stable during the saturation and hydrate formation processes, illustrating that it can be used repeatedly.
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