METHOD OF PYROLYSIS GAS PURIFICATION FROM HYDROGEN SULFIDE AND CARBON DIOXIDE Russian patent published in 1999 - IPC

FIELD: petroleum processing and petrochemical processes. SUBSTANCE: hydrogen sulfide and carbon dioxide are absorbed in aqueous sodium hydroxide solution and hydrocarbons and polymers entrained from pyrolysis gas are removed from exhausted absorption solution. Part of this solution is then combined with fresh 15-22% sodium hydroxide solution at volume ratio from 0.5: 1 to 2: 1. If content of hydrocarbons and polymers in exhausted absorption solution is below 300 mg/l, they are removed by simple settling. When their content exceeds 300 mg/l, extraction with organic solvent is involved at solvent-to-absorption solution volume ratio (0.5-1):1 followed by spontaneous separation of aqueous and hydrocarbon phases. EFFECT: increased sodium salt concentration in treated exhausted absorption solution. 1 dwg, 1 tbl, 5 ex