Multi-stage process for the separation and recovery of hcn and h2s from waste product gases containing ammonia

Claim 1

A MULTI-STAGE PROCESS FOR THE SEPARATION AND RECOVERY OF HCN AND H2S FROM A WASTE PRODUCT GAS WHICH ALSO CONTAINS AMMONIA, SAID PROCESS COMPRISING: INTRODUCING SAID WASTE PRODUCT GAS INTO A SATURATOR; CONTACTING SAID WASTE PRODUCT GAS IN SAID SATURATOR WITH A DILUTE SULFURIC ACID BATH AT AN ELEVATED TEMPERATURE FOR REMOVAL OF SAID AMMONIA AS AMMONIUM SULFATE; REMOVING FROM SAID SATURATOR A GAS WHICH IS SUBSTANTIALLY FREE OF AMMONIA BUT WHICH STILL CONTAINS SAID HCN AND H2S; COOLING SAID GAS FROM SAID SATURATOR; ABSORBING SUBSTANTIALLY FREE OF HCN; HCN AND A PORTION OF THE H2S CONTAINED IN SAID GAS FROM SAID SATURATOR BY CONTACT WITH WATER IN A WASHING ZONE RECOVERING FROM SAID WASHING ZONE THE WASHED PRODUCT GAS STEAM ENRICHED IN H2S AND SUBSTANTIALLY FREE OF CHN; LEADING THE WASH WATER CONTAINING HCN AND H2S INTO A FIRST STRIPPING ZONE WHEREIN SUBSTANTIALLY ALL OF SAID H2S AND A MONOR PROOPORTION OF SAID HCN IS STRIPPED FROM SAID WASH WATER BY CONTACT WITH A STRIPPING GAS WHICH IS PRACTICALLY INERT TO HCN; RECYCLING AND INTRODUCING THE EFFLUENT STRIPPING GAS FROM SAID FIRST STRIPPING WATER FROM SAID SATURATOR; LEADING THE PARTIALLY STRIPPED WATER FROM SAID RIST STRIPPING ZONE INTO A SECOND STRIPPING ZONE WHEREIN SUBSTANTIALLY ALL OF THE REMAINING HCN IS STRIPPED FROM THE WASH WATER BY CONTACT WITH A SECOND STRIPPING GAS WHICH IS PRACTICALLY INERT TO HCN; AND SEPARATING HCN FROM THE GAS STREAM BEING REMOVED FROM SAID SECOND STRIPPING ZONE.