H2S: Hydrogen sulfide treatment

TECHNOLOGY OF LIGHT HYDROCARBON FEED TREATMENT FROM HYDROGEN SULPHIDE

(«H₂S Removal-1» process)

Application area

Technology is used to treat hydrocarbon gases from hydrogen sulphide to a residual content of 10.0 ppm.

Assignment

Treatment of dry and liquefied hydrocarbon gases from hydrogen sulfide by aqueous solutions of alkanolamines at 10-45 °C temperature.

Concentration of hydrogen sulphide in hydrocarbon gas feed is up to 1.0% by weight, residual content of hydrogen sulfide is not more than 0.001% by weight.

Technology description

Schematic diagram of hydrocarbon gases treatment from H2S:

Hydrogen sulphide containing hydrocarbon gas enters the cube of T-101 column equipped with plates on which chemisorption of hydrogen sulfide occurs by an aqueous solution of alkanolamine according to the reactions 1- 2. The regenerated aqueous amine solution is fed to the top plate of the T-101 absorber.

H₂S + (HOCH₂CH₂)₂NH = (HOCH₂CH₂)₂NH₂SH (1)
(HOCH₂CH₂)₂NH₂SH + (HOCH₂CH₂)₂NH = [(HOCH₂CH₂)₂NH₂]₂S (2)

Aqueous amine solution saturated with hydrogen sulphide is removed from the bottom of T-101 column, heated in the heat exchanger E-101 up to 120 °C and through the distributor enters the regenerator R-101. Regeneration of amine proceeds according to the following reactions:

(HOCH₂CH₂)₂NH₂SH = H₂S + (HOCH₂CH₂)₂NH (3)
[(HOCH₂CH₂)₂NH₂]₂S = H₂S + 2(HOCH₂CH₂)₂NH (4)

From the top of R-101 regenerator, hydrogen sulphide and water vapors are sent through the condenser-cooler E-103 to the tank D-101. From the cube of R-101 regenerated amine solution is discharged into D-102 tank previously cooled in E-104 cooler to 40 °C. The gasses of aqueous amine solution regeneration from the top of D-101 tank are discharged through the knockout separator to the elemental sulfur production unit. Regenerated amine solution from the tank D-102 is fed to the T-101 column for irrigation by the pump P-102 A/B.

Advantages

Complex regenerative treatment of hydrocarbon gases from hydrogen sulphide. Absence of toxic sulphide-containing effluents formation.