Abstract:
Mercury can be observed in many of the world's natural gas fields. Natural gas process facilities with brazed aluminum heat exchangers, including LNG facilities and nitrogen rejection units, are particularly susceptible to corrosive attack by mercury. There is an increased awareness on the part of gas processors to better protect their assets and address environmental concerns by removing mercury at the most appropriate location from their facilities. There are many mercury removal technologies for natural gas, oil and produced water process facilities. Metal sulfide adsorbents and activated carbons are popular technique to remove mercury from natural gas and oil. However, there are some difficulties in mercury removal from oil. The reservoir properties data of the gas wells showed that the well fluids contain a maximum of 70 µg/Sm3 of mercury. The presence of mercury in the produced water , hydrocarbon liquids and export gas in the gas project were discussed. Technical and economical comparison were conducted between the all available technology methods for the removal of mercury from gaseous hydrocarbon, such as impregnated activated carbon, sulphided Zn/Cu oxide and mixed metal sulphides. It's recommended the use the sulphur impregnated metallic oxide technology for mercury removal in the gas stream and also concluded that the mercury removal unit should be located immediately after the inlet separator, upstream of CO2 removal, to avoid venting of mercury vapours from the CO2 vent and glycol still column overhead and to limit possible contamination of pipework especially the drain and vent lines. There is no apparent advantage to locating the mercury removal unit downstream of gas dehydration
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