Dehumidification performance of [EMIM]BF4

Some ionic liquids have dehumidification capacity and are non-corrosive to metals. Based on the Finite Difference Method, the heat and moisture transfer model of the counter-flow dehumidifier was established. Using this model, the dehumidification capacity of one kind of ionic liquids 1-Ethyl-3-methylimidazolium Tetrafluoroborate ([EMIM]BF4) and traditional desiccant lithium bromide (LiBr) was compared in equivalent conditions. The results show that the dehumidification performances of the two solutions both improve with the increase of air flow rate, solution flow rate and air humidity. Even though the dehumidification rate of [EMIM]BF4 is a little lower than that of LiBr, such difference could be reduced by increasing the mass concentration of [EMIM]BF4. Meanwhile, compared with traditional desiccants, [EMIM]BF4 solution has significantly lower corrosion to metals and does not crystallize at high mass concentration, which render it a possible substitute of existed desiccants in liquid desiccant air conditioning systems.