Separation of Ethane from Natural Gas Using Porous ZIF-8/Water–Glycol Slurry

Abstract

The high efficiency separation of ethane from natural gas becomes significant due to the occurrence of revolution in shale gas. Herein a new approach of continuous sorption separation was developed using a flowable zeolitic imidazolate framework-8 (ZIF-8) slurry. First, the sorption isotherms of CH4 and C2H6 in the ZIF-8 slurry were measured at 273.15–293.15 K, and the corresponding desorption heats are 13 and 20 kJ/mol, respectively. In comparison with the light oil absorption, higher ethane solubility in the slurry was observed. Next, the influences of temperature, equilibrium pressure, initial gas–slurry volume ratio, and feed gas composition on separation performance were studied by systematically measuring gas–slurry equilibria for CH4 + C2H6 mixtures. The pseudo P–T–x–y phase diagram shows that a minimum stage number of 6 was required for a thorough separation. Finally, the Langmuir equation was modified to fit gas–slurry equilibrium data by introducing cross interaction parameters. Both the experimental data and model are significant for the following design of the separation process using the ZIF-8 slurry.

Formation of a N/O/F-Rich and Rooflike Cluster-Based Highly Stable Cu(I/II)-MOF for Promising Pipeline Natural Gas Upgrading by the Recovery of Individual C3H8 and C2H6 Gases

“…Increasing amounts of natural gas (NG) will be annually consumed in the forthcoming decade. − After the removal of hydrocarbon gas liquids (HGLs) and other impurity gases from the NG, the pipeline NG consists of 70–96% CH 4 , a mixture of 0–20% C 2 H 6 and 0.01–5% C 3 H 8 , trace amounts of H 2 O, etc. − As one major C1 source to be sent to industrial plants for producing many important industrial consumables (e.g., methanol, formic acid, chloromethane, etc. ), ultrapure CH 4 gas is responsible for the high-quality downstream products. , On the other hand, C 3 H 8 and C 2 H 6 gases are both important raw materials of propylene and ethylene, respectively. ,,− To achieve ultrapure CH 4 gas and simultaneously recover the individual C 3 H 8 and C 2 H 6 gases, efficient pipeline NG upgrading by their recoveries is highly necessary. Currently, the production of the ultrapure CH 4 gas by the secondary low-temperature distillation of the byproduct from the helium extraction unit and the recoveries of C 3 H 8 and C 2 H 6 gases from the NG by the cryogenic fractional distillation process ,,, are both rather energy-consuming.…”

“…Moreover, the FTZB 2− ligand was viewed as a 2connected linker. Thus, the overall 3D framework of the porous N/O/F-heteroatom-rich mixed-valence Cu(I/II)-MOF was simplified to be a tsi topological network with a point symbol of {3 6 •4 16 •5 6 } (Figures 1a,c and S7), in which the 1D chain of SBB lay along the c-axis. In addition, the total potential solventaccessible volume in desolvated SNNU-Bai68 was around 43.4% as determined by the PLATON/SOLV program, 62 giving a calculated density of 1.29 g cm −3 for the desolvated framework.…”

Efficient separation of butane isomers via ZIF-8 slurry on laboratory- and pilot-scale

“…Li et al 43 successfully used a ZIF-8 slurry in a pilot-scale packed tower for CO 2 capture and achieved good separation efficiency, energy consumption, and stability during slurry operation. Pan et al 44 , Liu et al 42 , Chen et al 45 , and Yang et al 46 applied this method to separate a series of low boiling gas mixtures, such as natural gases, FCC dry gases, coalbed gases, IGCC syngas, etc. They all achieved promising results.…”

Experimental Study on Breakthrough Separation for Hydrogen Recovery from Coke Oven Gas Using ZIF-8 Slurry

“…Liu et al [21] proposed a ZIF-8/glycol-water slurry absorptionadsorption hybrid method to separate the gas mixture, where ZIF-8 can be suspended in water and maintain its adsorption performance because of its hydrophobicity and the similar density to water. By experiments, the solubility and separation performance of the slurry for carbon dioxide [22,23], low-boiling hydrocarbon [21], and their mixtures [24,25] were studied, and a continuous (ab-ad)sorption-desorption process was proposed with its mathematical model also developed [26]. Furthermore, the (ab-ad)sorption-desorption process was successfully run in a pilot-scale plant with promising results [27,28].…”