The crucial role of nMOFs in H2S absorption process using ionic liquid solution based nanofluid systems

Abstract

Ionic liquid solutions based of polyamines were synthesized and used for H2S removal. The results of simulation calculation and characterization showed that ionic liquid trap H2S by forming hydrogen bonds. Five nanometer-sized MOFs (nMOFs) were synthesized and added into ionic liquid solutions to build nanofluid systems. The effects of types, particle size, concentration, and regeneration gas of nanoparticles on the desulfurization performance of different nanofluids were explored. The addition of nMOFs with appropriate types and concentrations showed significant enhancement effect on the H2S absorption of liquid. Among five nMOFs, the systems of HKUST-1 and MIL-101(Fe) had high enhancement as well as regeneration performance at low concentrations (0.05 %). Based on sweep effect, gas–liquid mass transfer was enhanced by nMOFs due to the quickly capture and release of H2S. Furthermore, in this work, an “enrichment effect” has been proposed, in which H2S molecular enrichment zones were formed around nanoparticles, promoting gas–liquid reactions. The nanoparticles at different stages were characterized using X-ray photoelectron spectroscopy, scanning electron microscope, transmission electron microscope and energy dispersive spectrum, and the results confirmed that nMOFs have the ability to enrich H2S, which play a catalyst-like and accelerator-like role in H2S absorption process.