Process Description Feedstock – compressed APG contaminated with mercaptans is sent to the bottom part of absorber 1. A regenerated water solution of sodium hydroxide is supplied to the absorber overhead by pump 2 from vessel 3 after cooling in ACU 4, which absorbs mercaptans to form mercaptides. The treated gas from absorber 1 overhead is discharged from the unit. A saturated solution of sodium hydroxide is removed from the bottom of absorber 1, pressure is reduced using the device 5 and the solution is heated in a regenerative heat exchanger 6. The heated sodium hydroxide solution enters the regeneration column 7, the bottom part of which is heated by an external heat transfer medium in heat exchanger 8. A regenerated sodium hydroxide solution is removed from the bottom of column 7, cooled in heat exchanger 6 and fed into vessel 3, which is periodically fed with a fresh sodium hydroxide solution. The balance amount of the spent sodium hydroxide solution from container 3 is discharged into the drainage tank. Mercaptans and water vapor are removed from the top of column 7 and sent to ACU 9. The cooled mixture enters separator 10. The condensed water pumped by pump 11 is supplied for reflux of the top of column 7, and the mercaptans are sent for disposal.
Process features
Alkaline absorption demercaptanization of gases and liquids previously treated from hydrogen sulfide and carbon dioxide and regeneration of the absorbent by hydrolysis of mercaptides
Possibility of catalytic oxidation of mercaptan vapors with subsequent neutralization of alkaline effluents by oxidation gases
Technical Specification
Treated gas pressure 0,6 – 7,5 MPa
Temperature 15 – 45 ºС
It is possible to adapt this technology for the demercaptanization of liquid products the residual content of mercaptans in treated gas: less than 1 mg/m³
Patents of the Russian Federation No. At the patenting stage.