METHOD OF ALKALI PURIFICATION OF PYROLYSIS GASES Russian patent published in 2003 - IPC

FIELD: purification of pyrolysis gases of hydrocarbon raw materials from carbon dioxide and hydrogen sulfide; chemical and petrochemical industries. SUBSTANCE: proposed method includes absorption of carbon dioxide and hydrogen sulfide by aqueous solution of sodium hydroxide followed by purification of used alkali solution from emulsified liquid polymers, dissolved hydrocarbons and carbonates at subsequent recirculation of part of purified solution for absorption; used alkali solution is subjected to stepped physico-chemical treatment: neutralizing of solution by means of mineral acid or flue gases to pH=6-7, cleaning from dissolved carbonates, hydrocarbons and dispersed admixtures by settling them with the aid of successive proportioning into lime milk solution at dose of lime of 50-150 mg/l and ferrous sulfate at dose of 10-40 mg/l. Degree of cleaning pyrolysis gases from liquid polymers ranges from 80 to 93% and degree of cleaning from carbonates reaches 90%. EFFECT: enhanced efficiency. 2 dwg, 1 tbl, 4 ex