An ionic liquid process for mercury removal from natural gas

Abstract

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, resulting in the effective removal of mercury vapour from natural gas streams. This material has been commercialised for use within the petroleum gas production industry, and has currently been running continuously for three years on a natural gas plant in Malaysia. Here we report on the chemistry underlying this process, and demonstrate the transfer of this technology from gram to ton scale.

Mercury capture on a supported chlorocuprate(ii) ionic liquid adsorbent studied using operando synchrotron X-ray absorption spectroscopy

“…2 Elemental and ICP analysis of the supported ionic liquid gave copper and chloride contents of 2.0% and 3.3% (w/w), respectively, consistent with 10 wt% loading of [C 4 mim] 2 [Cu 2 Cl 6 ]. 60 mg of the sieved adsorbent was loaded as a short packed bed into the 3 mm i.d.…”

“…1 Recently, we demonstrated that supported chlorocuprate(II) ionic liquids were highly effective at capturing mercury from gases. 2 These supported ionic liquids have been successfully deployed in commercial scale mercury removal units in the oil and gas industry. 3,4 From our initial investigation, we proposed 2 that elemental mercury was trapped within the ionic liquid as a result of two-electron oxidation by chlorocuprate(II) anions, generating chloromercurate(II) species that were integrated as components of a new composite ionic liquid, following the scheme (with χ CuCl 2 = 0.5 in the ionic liquid 5 ):…”

“…In addition, while screening supported chlorocuprate(II) ionic liquids for mercury vapour capture, the quantity of mercury captured at the breakthrough point consistently approached half the molar copper content in the fixed-bed. 2 The binding and speciation on mercury on many conventional adsorbents has been studied using X-ray absorption spectroscopy (XAS). [6][7][8][9][10][11] Oxidation states, speciation and the formation of mercury oxide, chlorides or sulfides have been directly determined by combining X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS).…”

The crystal structure ofN-butylpyridinium bis(μ2-dichlorido)-tetrachloridodicopper(II), C18H28N2Cu2Cl6

“…[26][27][28][29]. Besides their intrinsic properties and application, MILs have also been used as ionic liquid precursors (ILPs) for inorganic nanomaterials, where the ILP acts as the solvent, the template, and the precursor for the inorganic material at the same time [19,30,31].…”

Infrared spectroscopic study of absorption and separation of CO using copper(i)-containing ionic liquids

“…46 Desulfurisation of gasoline by complexation of thiophene to Cu(I) in an ionic liquid has also been reported. 47 Most relevant to the present study is the recent work by Urtiaga and co-workers using CuCl dissolved in 1-hexyl-3-methylimidazolium chloride ([C 6 mim]Cl).…”