OUR PROCESS
Flue gas treatment
HIGH PERFORMANCE ACID
GAS TREATMENT
The semi-dry process consists of
simultaneously cooling and
injecting a liquid calcium reagent in
a reaction tower positioned
upstream of a fabric filter in order
to neutralise hydrogen chloride
(HCl) ; sulphur dioxide (SO2) ;
hydrogen fluoride (HF).
Semi-dry process
FIELD OF APPLICATION
 Ideally suited to high and very variable levels of acid
pollutants
 Recommended for use in treating flue gases in :
 Incineration of domestic and/or industrial waste
 Biomass combustion
 Coal-powered boiler rooms
 Coal-fired power stations
Process diagram
Operating principle
 Spraying lime slurry into a reactor, by spray nozzles or rotary atomizer, in order to solubilise and neutralise the acid
pollutants by gas-liquid contact
 Final filtration to catch reaction salts, fly ash and excess reagent and to finish the neutralisation of the pollutants
Performance
They are based on :
 The quality of the lime slurry preparation using quick lime or hydrated lime
 Optimising the constitutive parameters of the lime slurry (particle size, concentration and viscosity)
 The fineness of the lime slurry droplets sprayed into the reactor
 Complete evaporation of the lime slurry at the outlet of the reactor
 Optimisation of the resident time and contact time and quality of the flue gases/reagent mixture
 The quality and design of the final filtration system
Main advantages
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Reduction in the visible plume at the stack outlet
Neutralisation of acid pollutants in the reaction tower
Partial catchment of gaseous heavy metals in the reaction tower
Simultaneous treatment of dioxins/furans and gaseous heavy metals by injecting activated carbon or lignite coke in
dry, powdered form
 Treatment of pollutants with a very high concentration by using a post-injection of an addition reagent in dry,
powdered form
 Use of limestone milk for very large facilities
Semi-dry process
Full installation incorporating VINCI Environnement technologies (rotary atomizer reactor,
evaporating tower, fabric filter)
CAPACITY : 10,000 to 500,000 Nm3/h
 Turn-key installation of new solution or retrofitting
 Implementation requiring large set-up volume
 Very high levels of environmental performance
 Easy operation and maintenance
DTF V1 07/12