Patent ID: 8647411
Filing Date: 2014-02-11
Classification: B01D

Abstract:
1. A method of removing, at least partly, mercury from a process gas by means of a mercury absorbing sorbent and a filter, comprising: applying said sorbent to at least one filtering surface of said filter, measuring upstream of said filter at least one first parameter indicative of an amount of mercury to be removed in said filter, measuring at least one second parameter indicative of an amount of material collected on said filtering surface to determine when the filtering surface should be cleaned, comparing a measured value of said first parameter to a mercury set point, and delaying the cleaning of said filtering surface, when said measured value of said first parameter indicates an amount of mercury higher than the mercury set point, for a period of time greater than a period of time suggested by a measured value of said second parameter, wherein said second parameter is a pressure drop over said filter; and initiating the cleaning of the filtering surface at a selected intensity when said measured value of said second parameter exceeds a first pressure drop set point when the measured value of said first parameter indicates an amount of mercury equal to or lower than the amount of mercury indicated by the mercury set point, and when said second parameter exceeds a second pressure drop set point with a higher pressure drop than the first pressure drop set point when said measured value of said first parameter indicates an amount of mercury higher than an amount of mercury indicated by said mercury set point, for increased mercury removal.