Method for minimizing environmental release of toxic compounds in the incineration of wastes
A method is described for reducing the discharge of contaminated liquid streams in the treatment of hot waste incinerator exhaust gases containing hydrochloric acid gas, particulate fly ash, toxic metal oxides and toxic organic compounds, comprising the steps of: contacting the exhaust gases with an alkaline material; reacting the major portion of the hydrochloric acid gas content of the exhaust gases with the alkaline material; removing substantially all of the reacted spent alkaline material, fly ash and other particulate matter from the gas in a solids separation stage; treating the particulate-free exhaust gases from the solids separation stage in at least two wet scrubber contact stages operating in series; operating each of the wet scrubber stages with separate dedicated salt-free aqueous scrubbing solutions; scrubbing the gas in the successive wet scrubber contact stages with acid solutions of diminishing acid concentration; absorbing in the scrubbing liquor of the wet scrubber stages substantially all of the residual hydrochloric acid and a portion of the toxic organic compounds from the particulate-free exhaust gases; operating at least the first wet scrubber stage with a recycle aqueous salt-free scrubbing solution loop; recycling a portion of the aqueous acid scrubbing solution from a downstream wet scrubber stage to the initial wet scrubber contactor stage; collecting and conveying the contaminated acid liquid blowdown stream from the initial wet scrubbing liquid recycle loop to the waste incinerator; reincinerating the acid liquor blowdown stream in the waste incinerator for destruction of the organic toxics; removing the major portion of the recycled acid gas in the first alkaline dry solids gas treatment stage and thereby eliminating discharge of a contaminated liquid stream to the environment; and thereafter recovering a purified gaseous stream from the wet scrubbing stages.
- Assignee:
- Beco Engineering Co., Oakmont, PA (United States)
- Patent Number(s):
- US 5238665; A
- Application Number:
- PPN: US 7-712475
- OSTI ID:
- 6251167
- Country of Publication:
- United States
- Language:
- English
Similar Records
Wet scrubbers: Match the spray nozzle to the operation
Process for the removal of acid gases from gas mixtures
Related Subjects
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
CHLORINE COMPOUNDS
DETOXIFICATION
ELEMENTS
EXHAUST GASES
FLUIDS
GASEOUS WASTES
GASES
HALOGEN COMPOUNDS
HAZARDOUS MATERIALS
HYDROCHLORIC ACID
HYDROGEN COMPOUNDS
INCINERATORS
INORGANIC ACIDS
LIQUID WASTES
MANAGEMENT
MATERIALS
METALS
ORGANIC COMPOUNDS
PARTICLES
PARTICULATES
PROCESSING
TOXIC MATERIALS
WASTE MANAGEMENT
WASTE PROCESSING
WASTES