Production of argon free oxygen by adsorptive air separation on Ag‐ETS‐10

Abstract

in Wiley Online Library (wileyonlinelibrary.com).The purification of different components of air, such as oxygen, nitrogen, and argon, is an important industrial process. Pressure swing adsorption (PSA) is surpassing the traditional cryogenic distillation for many air separation applications, because of its lower energy consumption. Unfortunately, the oxygen product purity in an industrial PSA process is typically limited to 95% due to the presence of argon which always shows the same adsorption equilibrium properties as oxygen on most molecular sieves. Recent work investigating the adsorption of nitrogen, oxygen and argon on the surface of silverexchanged Engelhard Titanosilicate-10 (ETS-10), indicates that this molecular sieve is promising as an adsorbent capable of producing high-purity oxygen. High-purity oxygen (99.7þ%) was generated using a bed of Ag-ETS-10 granules to separate air (78% N 2 , 21% O 2 , 1% Ar) at 25 C and 100 kPa, with an O 2 recovery rate greater than 30%. V V C 2012 American Institute of Chemical Engineers AIChE J, 59: 982-987, 2013 Compressed air (a mixture of 78% N 2 , 21% O 2 and 1% Ar) was introduced into a column containing 130 g of pelletized Ag-ETS-10 (sieved to a size between 0.28-0.84 mm) at a flow rate of 126 mL/min (bed volume 150 mL). Composition of the outlet gas was determined by GC analysis.

A DFT study on the interaction of small molecules with alkali metal ion-exchanged ETS-10

“…The ability of cation exchange in ETS-10 can be exploited, for instance, to design appropriate adsorbents for temperature/pressure swing adsorption (TSA/PSA) techniques. [9][10][11][12][13][14] In fact, ETS-10 has been suggested as an adsorbent for gas separation processes by several authors. 9,10,12,15,16 For instance, Al-Baghli et al 9 and Anson et al 12 reported that CH4 and hydrocarbons can be captured employing the adsorptive separation technique, while Kuznicki et al 4,17 evidenced the good capacities of ETS-10 to separate N2 from landfill gas and air.…”

Hydrophobic dipeptide crystals: a promising Ag-free class of ultramicroporous materials showing argon/oxygen adsorption selectivity

“…The potential for PSA separation of Ar/O2 mixtures of Ag-mordenite was immediately recognised 23 . In the next two decades, several articles and patents followed, describing adsorbents with greater selectivities and capacities, as well as more efficient O2-generating PSA processes 20,22,24,27,[29][30][31][32] .…”

Redox‐Active Metal–Organic Composites for Highly Selective Oxygen Separation Applications

“…Therefore, there is an urgent need for alternative technologies and novel materials for energy‐ and cost‐efficient oxygen separation from air. Zeolite molecular sieves have been used for O 2 adsorption and separation, but still fall short compared to recently reported solid state adsorbents based on high surface area, crystalline metal–organic frameworks (MOFs) . In this regard, selective adsorption of O 2 from N 2 using M 2+ based MOFs—M 3 (btc) 2 (M = Cr, Fe; btc 3 = 1,3,5‐benzenetricarboxylate) and MOF‐74 Fe—are shown to exhibit steep O 2 ‐adsorption isotherms at room temperature (RT) .…”