(19e) Mercury Removal From Gaseous and Liquid Hydrocarbons

Mercury is present in many of the world’s oil & gas fields and its removal and capture is important for a number of reasons:

* Process plants with brazed aluminium heat exchangers are susceptible to corrosive attack by mercury
* Product streams eg. naphtha are less valuable to producers when “distressed” by mercury
* Many refinery & petrochemical catalysts are poisoned by mercury
* Mercury is toxic and should be removed on health and safety grounds

In supplying purification solutions to the oil & gas processing industry, UOP has developed a number of approaches for removing mercury using non-regenerative metal oxide and metal sulfide technology in both gas and liquid phase streams.

A comparison of mercury removal processes is described and several commercial case histories are presented. The plant specific drivers leading to the adoption of these technologies are discussed and the efficacy of each approach is critically assessed.

The accurate measurement of various mercury species in process streams is key in determining the selection of the most appropriate purification technology. A number of analytical techniques are available to measure mercury down to ppb levels and it is important for process plant operators to consider how mercury is measured in order to remove mercury to ultra low levels. The latest proven analytical methods for the measurement are reviewed and discussed.