Extraction of propane and ethane from natural gas on ultramicroporous carbon adsorbent with record selectivity

Abstract

The separation of light hydrocarbon mixtures and the extraction of C 3 H 8 and C 2 H 6 from natural gas are of significant importance in natural gas purification and upgrading. Microporous carbon adsorbents are promising in light hydrocarbon separation. However, the fabrication of uniform ultramicropores to boost separation selectivity remains challenging. Herein, we fabricated a series of poly(vinylidene chloride)-resin-derived ultramicroporous carbon adsorbents with a relatively uniform pore size (5.2-5.3 Å) by activator-free pyrolysis. The optimal C-PVDC-800 exhibited record-high ideal adsorption solution theory (IAST) selectivity for C 3 H 8 /CH 4 (3387) and C 2 H 6 /CH 4 (75) and Henry's selectivity for C 3 H 8 /CH 4 (369) among all reported adsorbents under ambient conditions, combined with ultrahigh uptake of C 3 H 8 (3.9 mmol g −1 , 0.05 bar) and C 2 H 6 (2.67 mmol g −1 , 0.10 bar) at low partial pressures and 298 K. More importantly, fast gas adsorption kinetics favorable for fixed-bed adsorption applications was realized. Breakthrough experiments and cycling tests further confirm the superb separation performance of the extraction of C 3 H 8 and C 2 H 6 from natural gas.

Molecular Sieving of Propylene from Propane in Metal–Organic Framework-Derived Ultramicroporous Carbon Adsorbents

“…Moreover, it may also lead to the polymerization of olefins . By contrast, easier regeneration processes and less energy consumption make porous carbon adsorbents promising candidates for industrial applications. ,,, …”

“…38 By contrast, easier regeneration processes and less energy consumption make porous carbon adsorbents promising candidates for industrial applications. 15,36,39,40 Traditional porous carbon adsorbents are mainly prepared using polymers 41−44 and biomass 45−47 as precursors via a chemical activation method. However, the complicated pyrolysis process and the nanocrystalline amorphous structure typically lead to random distributions and arrangements of the internal pores in the carbons.…”

Ultramicroporous Lonsdaleite Topology MOF with High Propane Uptake and Propane/Methane Selectivity for Propane Capture from Simulated Natural Gas

“…During the DCB experiment, 0.48 mmol g –1 C 2 H 6 and 2.45 mmol g –1 C 3 H 8 were found to be absorbed by CMOM-7 (Table S6). The dynamic uptake of C 3 H 8 exceeded several NG separating sorbents including BSF-2 (∼0.76 mmol g –1 ), C-PVDC-800 (3.02 mmol g –1 ), ZUL-C1 (1.90 mmol g –1 ), ZUL-C2 (1.92 mmol g –1 ), and MIL-101-Cr (0.60 mmol g –1 ) …”

Quasi-Discrete Pore Engineering via Ligand Racemization in Metal–Organic Frameworks for Thermodynamic–Kinetic Synergistic Separation of Propylene and Propane

“…However, the presence of propane, an unavoidable byproduct of naphtha steam cracking or gas oil catalytic cracking, constrains propylene’s utility. − Currently, the industrial separation of propylene and propane still heavily relies on an energy-intensive cryogenic distillation process. Alternatively, adsorption separation technology offers significant advantages, notably high energy efficiency and milder operating conditions. ,− Nonetheless, the striking structural similarities, nearly identical dimensions, and close physical properties of propane and propylene pose a daunting challenge to their efficient separation. , …”