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Superiority of silica supported ionic liquids over other adsorbents in capturing elemental mercury (Hg0) from flue gases has been recently reported. In this study, activated carbon, which is more economical than silica, was experimented as a solid support for ionic liquids (ILs) for gaseous Hg0 removal. Four ILs were successfully coated on activated carbon. The carbon supported ionic liquids (CSILs) were characterized by Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller surface area analysis, field emission scanning electron microscopy, energy-dispersive X-ray, X ray-photoelectron spectroscopy and nuclear magnetic resonance. A continuous fixed bed flow reactor was used to examine the performance of CSILs in treating 20–35 ppm Hg0 vapor at a gas flow rate of 60 mL/min. 1-Butyl-3-methylimidazolium chloride [Bmim]Cl coated activated carbon was the most reactive among CSILs studied and a powdered form of [Bmim]Cl coated activated carbon was able to uptake Hg0 up to 23 mg/g and 60 mg/g with N2 and CH4 as carrier gas, respectively. A molecular simulation was performed to investigate the molecular level interaction between the Hg0 and the ILs to understand the effect of structural variations of the ILs on Hg0 adsorption. The simulation reveals that the anion part of IL plays a major role in Hg0 adsorption. Based on experimental results, a possible mechanism of Hg–IL interaction was elucidated; the imidazolium cation can form a complex with HgCl2 through the C2 hydrogen.

Solid-supported ionic liquids (ILs) have recently received attention as a potential effective technology for mercury removal from a gas stream. However, the leaching of ILs from the solid support has not been investigated in detail. In the present study, the stability of 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) impregnated on silica and activated carbon was evaluated during elemental mercury removal (Hg0) from a gas stream. Silica- and carbon-supported [Bmim]Cl-based adsorbents were characterized before and after Hg0 adsorption by using Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller surface area analysis, field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermal gravimetric analysis. The carbon-supported adsorbent showed better stability (no leaching of ILs) compared to the silica-supported adsorbent because of the availability of substantial micropores. The lower stability of silica-supported ILs is attributed to the presence of mesopores on si...

An increasing trend of contaminants in the oil and gas streams has been observed worldwide in the past recent years, and one of the eminent naturally occurring contaminant is mercury. Mercury has been found to be hazardous to health, safety, and environment as well as detrimental to process equipment at the oil and gas plants. The complexity in removing mercury is due to its existence in different species, mainly elemental, organo- and inorgano-mercury. Most available technologies for mercury removal are located downstream of the acid gas removal and dehydration units and thus, leading to contamination of these units as well as mercury release to the environment. Besides its potential to be located upstream of these units to better protect the plant operations, the new technology is capable of treating the full range of mercury species by a single adsorbent or treatment step to meet the current targeted mercury level at outlet of mercury removal unit of less than 0.01 ug m-3. In addition, it can be applied to the existing mercury removal units without requiring any plant modifications or retrofitting. A joint collaboration between PETRONAS and Queen's University Belfast has led to a development of a new technology that effectively removes mercury from oil and gas streams utilising ionic liquids. Efficient scrubbing of mercury vapour from natural gas streams has been demonstrated both in the laboratory and on an industrial scale, using chlorocuprate(II) ionic liquids impregnated on high surface area porous solid supports. This material has been tested for use within the petroleum gas production industry, and has currently been running continuously at a number of gas processing plants in Malaysia for more than three years. Since it was originally revealed, further innovative developments have been undertaken to improve its efficiency and performance for applications in liquid hydrocarbon streams. Recognitions and awards have also been received from various organisations including iChemE for the technology. Since it was originally revealed, further innovative developments have been undertaken to improve its efficiency and performance for applications in liquid hydrocarbon streams.