Flue Gas Conditioning

Improve Performance of Electrostatic Precipitators (ESPs) and Capture of Flyash and Particulate

• Injection of SO₃ and ammonia into flue gas to improve operation of Electrostatic Precipitators (ESPs)
• Reduces flyash resistivity and improves ESP capture of fine particulate for reduced opacity and emissions
• Technology proven on over 500 ESPs worldwide

Flyash precipitators do not operate effectively when there is not sufficient sulfur trioxide (SO₃) is not present in the flue gas. By injecting SO₃ and, in some cases, ammonia into the flue gas the performance of Electrostatic Precipitators (ESPs) is improved without increasing SO_X emissions. The conditioning gas necessary for the FGC process is produced by burning elemental sulfur to produce SO_2, which is converted to SO₃ with a catalyst and injected into the flue gas at levels normally less than 20 ppm.

System installation costs can be greatly reduced by designing modular equipment. Whenever possible, Fuel Tech system design is “containerized” by factory-assembling the process equipment inside a permanent enclosure prior to shipment. This minimizes installation time and expenses, and negates the need for separate, dedicated buildings.

Chemical feedstock costs and external energy input are significant. As such, catalytic converters should be as efficient as possible to minimize the flow of molten sulfur feedstock to the system, as well as, the cost of unused chemical exiting the stack. For this reason, the standard catalytic converter is a two pass design and 95% conversion efficiency is guaranteed. All systems are designed for high SO₂ and SO₃ gas concentrations to minimize external energy input and reduce the size of the field-installed piping needed to transport the conditioning gas to the injection probes mounted in the ductwork.

Systems

There are two sulfur options: molten sulfur and pelletized dry sulfur technology. Ammonia systems can be operated independently or added to SO₃ injection for "dual conditioning." The system best for you is unique to your operation’s capacity and flyash conditioning needs, as well as, the type of coal burned. 

Ammonia Systems

Dual Flue Gas Conditioning

Ammonia systems are available using anhydrous or aqueous ammonia. NH₃ is effective alone in certain precipitator enhancement applications, or also in conjunction with SO₃ creating a "dual"  gas conditioning process. NH₃ can also be used as SO₃ Mitigation Technology.

• Wide range of system size availability.
• When Dual System is installed, some SO₃ equipment (such as the air blower & PLC) can be shared with NH₃ dilution.
• Urea based systems provide safer reagent
• Dual FGC required for high-ash coals and flyash where SO₃ alone is not sufficient
• Works well on high ash coals (China and India)
• Supplied as modular system