Gas purification system

A system for purifying coal carbonization product gas containing NCN gas, H.sub.2 S gas and NH.sub.3 gas, comprising:

• first treatment means including a closed chamber which receives said coal carbonization product gas at a lower portion thereof, spray means mounted in an upper portion of said chamber to spray an alkaline absorbent liquid for contact with said coal carbonization product gas,
• absorbent liquid resuscitation means including a further closed chamber connected to said first treatment means through a pump and recirculation conduit means,
• nozzle means connected to said recirculation conduit means which feeds the absorbent liquid received from said first treatment means, together with an oxygen containing resuscitation gas, into said resuscitation means,
• a further recirculation circuit means connected to said resuscitation means and said spray means which feeds the absorbent liquid resuscitated in said resuscitation means to said spray means, and
• second treatment means connected to a top portion of said first treatment means through supply conduit means, said second treatment means being adapted to remove NH.sub.3 gas remaining in the coal carbonization gas sent from said first treatment means,
• said nozzle means is in a form of a premix nozzle including therein a resuscitation gas passage joining an absorbent liquid passage, whereby the resuscitation gas is mixed into the absorbent liquid in fine bubbles prior to entry into said resuscitation means, and
• said resuscitation means is connected at a top portion to an upstream side of said second treatment means, whereby the resuscitation gas discharged from said resuscitation means is delivered to said second treatment means confluently with the coal carbonization product gas discharged from said first treatment means.