Investigations in the field of flue gas cleaning, especially focusing on DeNOx and the removal of fly ash, halides, sulfur dioxide and mercury of firing processes of thermal power plants can be carried out at IFK’s laboratory-scale furnace system with a thermal power of 2 kW. This test facility consists of a burning chamber, cooling zone, SCR-DeNOx reactor, electric precipitator and a dual-loop flue gas desulfurization system using the process of wet lime washing.
Laboratory furnace
- Vertical, top-fired burning chamber made of quarz glass with a thermal power of 2 kW
- Burning chamber diameter: 150 mm
- Burning chamber length: 1500 mm
- Burning chamber temperature: up to 1200 °C
- Variable Swirl burner for pulverized fuels (D50 <100 µm)
- Fuel dosing with a volumetric dosing unit
- Fuel mass flow: 0.1-0.3 kg/h (dependent of fuel)
- Fuels: hard coal, biomass mixtures (0-100%), fuel mixtures with additives, pulverized refuse derived fuels
- Flue gas flow: up to 2.5 m³/h STP, dry
SCR-DeNOx-Reactor
The use of SCR-DeNOx catalysts is state of the art to comply with the emission limits of nitrogen oxide in coal fired power plants. Several investigations have shown that the oxidation of fuel released elemental mercury occurs at the catalyst. Oxidized mercury can, in opposite to elemental mercury, be removed very well in the downstream wet flue gas desulfurization system. The increasing use of refuse derived fuels and biomass in coal fired power plants leads to different flue gas matrices for the catalysts.
- Glass setup
- Temperature: between 280°C and 420°C
- Diameter: 35 mm, Length: 1000 mm
- Plate or honeycomb catalyst with typically 3x3 channels (for 7 mm pitch)
- Ammonia dosing
- Measurement of the DeNOx-activity, mercury oxidation and SO2/SO3-conversion
- Effect of the use of additives on the catalysts
Electrostatic precipitator (ESP)
The removal of fly ash is provided by a heated electrostatic precipator. The removal rate can be set to favored values. Specific investigations regarding to the adsorption of certain pollutants at fly ash as well as the sampling of different fly ash fractions is possible.
- Heated up to 200°C
- Voltage: 24 kV
- Current: 0.5 mA
- Removal rate > 99 % (particle size spectrum from 0.1 to 10 µm)
- Optional removal of finest particles with glass wool filter
Dual- or single-loop Flue Gas Desulfurization System
In order to observe the sulfur dioxide emission limits of fossil fired power plants, the wet flue gas desulfurization (FGD) constitutes the state of the art technology. In Germany, the most frequently applied method is the wet scrubbing process with limestone. In the course of this, the calcium carbonate (CaCO3) – which is predominantly existent in the utilised limestone - in intermediate steps undergoes a reaction to the final product calcium sulfate dihydrate (CaSO4•2H2O), which can be dehydrated and further used commercially in different steps of secondary treatment (FGD-gypsum). In the dual-loop scrubber, the flue gas flows through two washing stages with different slurry compositions and states, influencing precipitation behaviour. It can be also operated as a single-loop FGD.
- Flue gas flow: up to 2.5 m³/h STP, dry
- Retention time: Quencher 4 sec / Absorber 6 sec (variable)
- Variable L/G-ratio set in Absorber and Quencher
- Automatic pH value control in the Absorber
- External sump with oxidation air supply
- Variable airation with air or oxygen
- Used media: calcium carbonate, limestone, quicklime, additives
Contact
Marc Oliver Schmid
Department Flue Gas Cleaning and Air Quality Control (RuL)
Deputy Head of Department