PROCESS, METHOD AND SYSTEM FOR REMOVING HEAVY METALS FROM FLUIDS Russian patent published in 2018 - IPC C01G17/00 C10G27/10 C10G27/12 C10G27/14 C10G29/10 C10G29/28 C10G31/09 B01D37/02 

FIELD: oil and gas industry.

SUBSTANCE: invention relates to an improved method for reducing trace amounts of mercury in crude oil feedstock, which comprises passing crude oil feedstock characterised by a certain a mercury concentration, as feed stream to a filtration device having at least a filter element to generate a filtered crude having a reduced concentration of mercury, and a reject stream containing crude oil having a concentrated of mercury level of at least 10 times the concentration of mercury in the crude oil feed; mixing into the reject stream an effective amount of an extractive agent to remove at least a portion of the mercury for a treated crude oil having a reduced concentration of mercury; wherein the extractive agent is selected from the group of oxidising agents; reducing agents, organic or inorganic sulphides with at least one sulphur atom reactive with mercury; tetrakis(hydroxymethyl)phosphonium sulphate; tetrakis(hydroxymethyl)phosphonium chloride; and combinations thereof. Invention also relates to an improved method for reducing the trace amount of mercury in a crude oil feedstock comprising passing crude oil feedstock having a certain mercury concentration, through a filtration device with a filter element, to retain at least 50 % of the mercury on the filter element and generate a filtered crude having a reduced concentration of mercury; back-flushing the filtration device with a portion of the filtered crude to generate a reject stream containing crude oil having a concentrated mercury level of at least 20 times the concentration of mercury in the fed crude; mixing into the reject stream an effective amount of an extractive agent to convert at least a portion of the mercury into volatile mercury; removing a portion of the volatile mercury using one of the following methods: stripping, scrubbing, adsorption and combinations thereof to obtain a treated crude oil having a reduced concentration of mercury.

EFFECT: process, a method and a system for removing heavy metals from fluids are proposed.

17 cl, 5 ex, 2 tbl, 1 dwg