MECHANISTIC STUDY OF MERCURY REMOVAL FROM GAS STREAM USING SOLID SUPPORTED IONIC LIQUIDS

Mercury removal from natural gas streams is becoming more challenging due to
stringent regulations. Mercury in natural gas is generally present in two forms;
elemental mercury (Hg°) and organo-mercury. The Hg° in the vapor phase is
dominant in nature and accounts for 90% of mercury species in natural gas. It is
difficult to control due to its high volatility, less solubility and low reactivity.
Currently, a number of technologies are commercially available to reduce mercury
contents in natural gas including adsorption on activated carbon, halide or sulfur
impregnated activated carbon, metal sulfides on alumina, and molecular sieves
incorporating silver. However, not all of these systems are able to remove Hg
efficiently. In the meantime, increasing trend of mercury contents especially in
Southeast Asia in gas reservoir encouraged researchers to find robust technology for
its removal. Recently, superiority of silica supported ionic liquids over other
adsorbents in capturing Hg° from flue gases has been reported.