Effects of water on the removal of methyl bromide using triethylene diamine impregnated carbon

The removal of methyl bromide (CH3Br) from streams of dry and humid air was investigated using coconut shell carbon impregnated with triethylene diamine (TEDA). The relative humidity of the air stream had a significant effect on the CH3Br breakthrough time, but not the removal capacity, especially as the relative humidity of the air stream was increased to greater than 50%. The decrease in the breakthrough time was attributed to an increased in the amount of water physically adsorbed by the carbon substrate, leading to a significant decrease in the CH3Br adsorption capacity. NMR results revealed TEDA was reacting directly with CH3Br, leading to the formation of primarily a mono-substituted quaternary amine, with only small amounts of the di-substituted quaternary amine detected.