One‐step Ethylene Purification from an Acetylene/Ethylene/Ethane Ternary Mixture by Cyclopentadiene Cobalt‐Functionalized Metal–Organic Frameworks

Abstract

The separation of ethylene (C 2 H 4 )from amixture of ethane (C 2 H 6 ), ethylene (C 2 H 4 ), and acetylene (C 2 H 2 )a t normal temperature and pressure is as ignificant challenge. The sieving effect of pores is powerless due to the similar molecular size and kinetic diameter of these molecules.W e report an ew modification method based on as table ftw topological Zr-MOF platform (MOF-525). Introduction of acyclopentadiene cobalt functional group led to new ftw-type MOFs materials (UPC-612 and UPC-613), which increase the host-guest interaction and achieve efficient ethylene purification from the mixture of hydrocarbon gases.T he high performance of UPC-612 and UPC-613 for C 2 H 2 /C 2 H 4 / C 2 H 6 separation has been verified by gas sorption isotherms, density functional theory (DFT), and experimentally determined breakthrough curves.T his work provides ao ne-step separation of the ternary gas mixture and can further serve as ablueprint for the design and construction of function-oriented porous structures for such applications.

One-step ethylene production from a four-component gas mixture by a single physisorbent

“…2f , at 298 K and 100 kPa, the selectivities are 1.43 (C 2 H 2 /C 2 H 4 ), 1.27 (C 2 H 6 /C 2 H 4 ), and 1.33 (CO 2 /C 2 H 4 ). C 2 H 6 /C 2 H 4 and C 2 H 2 /C 2 H 4 selectivities for Zn-atz-oba are comparable to the current benchmark sorbents that enable C 2 H 4 purification from C 2 H 2 /C 2 H 4 /C 2 H 6 1:1:1 ternary mixtures (1.2 and 1.8 for TJT-100 35 , 1.46 and 1.09 for Azole-Th-1 36 , 1.32 and 1.4 for NPU-1 39 , 1.4 and 1.07 for UPC-612 and 1.5 and 1.4 for UPC-613 41 , respectively) (Supplementary Table 3 ). The selectivity for CO 2 /C 2 H 4 is also comparable to that of C 2 H 6 /C 2 H 4 and C 2 H 2 /C 2 H 4 .…”

“…If one compares the performances of previously reported physisorbents in the context of ethylene purification from binary mixtures 15 – 20 , 22 – 30 , 32 , 46 (C 2 H 2 /C 2 H 4 , C 2 H 6 /C 2 H 4 , and C 2 H 4 /CO 2 ) and ternary mixtures 35 , 36 , 39 – 41 (C 2 H 2 /C 2 H 4 /C 2 H 6 , C 2 H 2 /C 2 H 4 /CO 2 , and C 2 H 6 /C 2 H 4 /CO 2 ), it is evident that Zn-atz-oba represents a benchmark in terms of its performance parameters (Fig. 5 ).…”

“… Comparison of physisorbents that can purify C 2 H 4 from binary (sky blue) 15 – 20 , 22 – 30 , 32 , 46 , ternary (olive green) 35 , 36 , 39 – 41 and quaternary mixtures (lilac, this work) under ambient conditions. …”

“…Since the quadrupole moment of C 2 H 4 (1.5 × 10 −26 esu cm 2 ) also lies between CO 2 (4.3 × 10 −26 cm 2 ), C 2 H 2 (7.2 × 10 −26 esu cm 2 ) and C 2 H 6 (0.65 × 10 −26 esu cm 2 ) 8 , one-step purification of C 2 H 4 by thermodynamics (selective binding) has thus far proven to be elusive. Metal organic materials (MOMs) 9 , also called metal-organic frameworks (MOFs) 10 , 11 or porous coordination polymers (PCPs) 12 , have promising applications as C2 and CO 2 selective physisorbents for several binary mixtures, including C 2 H 2 /C 2 H 4 , C 2 H 4 /C 2 H 6 , C 2 H 6 /C 2 H 4 , C 2 H 2 /CO 2 and CO 2 /C 2 H 2 13 – 34 There are also examples of physisorbents that are effective against ternary C2 and C2-CO 2 mixtures such as C 2 H 2 /C 2 H 4 /C 2 H 6 and C 2 H 2 /C 2 H 4 /CO 2 35 – 41 . Certain classes of physisorbents are amenable to systematic fine-tuning of pore chemistry and pore size 42 , 43 and have resulted in “second generation” sorbents with > one order of magnitude improvement in performance 18 , 24 , 44 , 45 , 47 .…”

Th-MOF showing six-fold imide-sealed pockets for middle-size-separation of propane from nature gas

“…The size and con guration of pore in MOFs presents a highly important factor for separation [25][26][27][28][29] . MOFs could selective adsorption of gas molecules with smaller size than the pore MOFs, but will exclude these gas molecules with bigger size than the pore MOFs 30,31 .…”