HYDROCHLORIC ACID VAPOR REDUCTION & RECOVERY
HYDROCHRLORIC ACID REVOVERY FROM CHLORINATED ORGANIC VAPOR THERMAL OXIDIZER FLUEGAS
Manufacture of various Chlorinated organic chemicals results in spent vapors of product in air too dilute to recover. These vapors are often sent to thermal oxidizers where one combustion product is HydroChloric acid (HCl) vapor. The thermal oxidizer fluegas cannot be exhausted to the atmosphere until this acid is removed.
The fluegas is typically very hot (800 DgC or hotter) and must be Quenched before being scrubbed of the acid. The usual method of scrubbing the acid is the use of a dilute Sodium alkali solution such as Caustic (NaOH). The resultant byproduct Sodium Chloride (NaCl) has no vapor pressure and is totally harmless.
As the gas concentration of the HCl increases, which happens frequently, the NaOH usage increases as does the operating cost. Fortunately, done properly a good portion of the HCl can be absorbed into water to create up to a 25 wt% solution which can be reused. The balance still must be absorbed into NaOH but its usage is significantly reduced.
In order to carry out the process correctly process data is required to take into account high heat of solution, vapor pressure of concentrated solutions and appropriate materials of construction. D. R. Technology has the appropriate data and background and has carried out this for clients in Texas Louisiana and India.