H2STECHNOLOGY 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 35-45 °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:

outline 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:

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-refrigerator 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 refrigerator 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.