Flue Gas Conditioning

• 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

Fuel Tech, Inc. licenses technology from FGC, Inc. to provide systems outside the US and Canada. Flyash precipitators will not operate effectively if sufficient Sulfur Trioxide (SO₃) is not present in the flue gas. By injecting SO₃ and, in some cases, ammonia into the flue gas it improves the performance of Electrostatic Precipitators (ESPs). All of the SO₃ attaches to the flyash and does not increase SO_x emissions.

To produce the desired conditioning gas in the FGC process, elemental sulfur is burned in a furnace which produces SO₂; SO₂ is converted to SO₃ with a catalyst and injected into the flue gas at levels normally less than 20 ppm.

Systems

There are two sulfur options: molten sulfur and pelletized dry sulfur (DSI™ 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.

Molten Sulfur

Molten sulfur is the most economical and common feedstock in U.S., widely available in bulk shipments. It’s non-hazardous and allows complete combustion within sulfur burner. It is reliably and accurately metered and transferred to burner; as well as, heated to temperature with plant steam or via small, electric steam boiler.

Equipment Sequence for Molten Sulfur:

• Molten Tank
• Metering Pumps
• SO₃Production
  • Air Blower
  • Air Heater
  • Sulfur Burner
  • SO₂/SO₃ Converter
• Injection Probes

Pelletized Sulfur (DSI™ Technology)

Pelletized Sulfur or Dry Sulfur Interface Technology (DSI™ Technology) provides substantial benefits, especially for smaller capacity units. It eliminates unloading of hot molten sulfur from a tanker truck and reduces steam usage and amount of jacketed interconnecting process piping. Dry Sulfur is shipped on pallets or in silo and can be stored indefinitely without need for steam heating. It has more flexibility in sulfur storage location and equipment layout and is widely available in one-ton super-sacks or bulk deliveries. As with molten sulfur, it is also non-hazardous.

Equipment Sequence for DSI™ Technology:

• Dry Unloading
• Dry Silo w/Conveyor
• Sulfur Melter
• Metering Pumps
• SO₃Production
  • Air Blower
  • Air Heater
  • Sulfur Burner
  • SO₂/SO₃ Converter
• Injection Probes

Ammonia Systems

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" 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)