Quasi-Orthogonal Configuration of Propylene within a Scalable Metal–Organic Framework Enables Its Purification from Quinary Propane Dehydrogenation Byproducts

Abstract

Propylene production via nonoxidative propane dehydrogenation (PDH) holds great promise in meeting growing global demand for propylene. Effective adsorptive purification of a low concentration of propylene from quinary PDH byproducts comprising methane (CH 4 ), ethylene (C 2 H 4 ), ethane (C 2 H 6 ), propylene (C 3 H 6 ), and propane (C 3 H 8 ) has been an unsolved academic bottleneck. Herein, we now report an ultramicroporous zinc metal−organic framework (Zn-MOF, termed as 1) underlying a rigid one-dimensional channel, enabling trace C 3 H 6 capture and effective separation from quinary PDH byproducts. Adsorption isotherms of 1 suggest a record-high C 3 H 6 uptake of 34.0/92.4 cm 3 cm −3 (0.01/0.1 bar) at 298 K. In situ spectroscopies, crystallographic experiments, and modeling have jointly elucidated that the outstanding propylene uptakes at lower pressure are dominated by multiple binding interactions and swift diffusion behavior, yielding quasi-orthogonal configuration of propylene in adaptive channels. Breakthrough tests demonstrate that 30.8 L of propylene with a serviceable purity of 95.0−99.4% can be accomplished from equimolar C 3 H 6 /C 3 H 8 mixtures for 1 kg of activated 1. Such an excellent property is also validated by the breakthrough tests of quinary mixtures containing CH 4 /C 2 H 4 /C 2 H 6 /C 3 H 6 /C 3 H 8 (3/5/6/ 42/44, v/v/v/v/v). Particularly, structurally stable 1 can be easily synthesized on the kilogram scale using cheap materials (only $167 for per kilogram of 1), which is important in industrial applications.

Induced‐Fit‐Identification in a Rigid Metal‐Organic Framework for ppm‐Level CO2 Removal and Ultra‐Pure CO Enrichment

“…Note that the simulated curves (Figure 4b) are somewhat sharper than those observed experimentally, mainly because intracrystalline diffusional influences were ignored in the simulations. [13,27] Notably, ultrapure CO purity (� 99.99 %) can be achieved at 298 K (Figure 4c), far exceeding that required for STO (� 99.5 %), indicative of great potential in ultra-pure CO enrichment.…”

“…Note that the approach is usually subject to limited requirements or uncertainties; thus, errors may occur due to narrow pores (nonideal gas solution) and structural flexibility. [27] Consequently, IAST selectivity was evaluated here just for qualitative analysis. Further, breakthrough tests were conducted to assess the CO 2 /CO separation performance.…”

Water-Stable Microporous Bipyrazole-Based Framework for Efficient Separation of MTO Products

“…The process of MTO to produce C 2 H 4 and C 3 H 6 was further developed. The contents of C 2 H 4 and C 3 H 6 produced by the MTO process are 51.1 and 20.9 wt %, respectively. − It is well known that the separation of C 2 H 4 and C 3 H 6 mixtures to obtain high-purity C 2 H 4 and C 3 H 6 is essential for industrial applications. However, the separation of C 2 H 4 and C 3 H 6 remains a great challenge due to the similarity of their physical properties.…”

Rational Construction of Ultrahigh Thermal Stable MOF for Efficient Separation of MTO Products and Natural Gas

“…The MOF with a layer-pillared network was constructed from judiciously selected methyl-functionalized pyrazole linkers and squaric acid pillars, possessing excellent resistance toward water, as well as exceptional thermal stability (520 °C). Zn-BPZ-SA reveals the high uptakes of 46.6 cm 3 g −1 for C 3 H 6 and 48.0 cm 3…”

“…Propylene (C 3 H 6 ) and ethylene (C 2 H 4 ) are crucial energy resources and also vitally important feedstocks in the chemical process industry. − The total global production of C 2 H 4 and C 3 H 6 ranks as the most chemical raw materials in the world. , The methanol-to-olefins (MTO) reaction is an important and advanced method for preparing C 2 H 4 from coal and natural gas, where the products contain ∼21 wt % C 3 H 6 and ∼51 wt % C 2 H 4 . , Therefore, separating C 3 H 6 and C 2 H 4 of MTO products is essential for downstream applications. The common separation process of C 3 H 6 and C 2 H 4 mixtures is mainly dependent upon the cryogenic distillation at high pressure, requiring large energy consumption accounting for more than 0.3% of the global energy needs. − Besides olefins, a second critical separation object is natural gas, predominantly composed of methane (CH 4 , 85%), ethane (C 2 H 6 , 9%), and propane (C 3 H 8 , 3%) .…”