O’Brien & Gere has conducted nearly 4,000 hours of demonstrations at 15 different units since January 2005 to demonstrate the viability of DI - Duct Injection Technologies™ to reduce SO₂, SO₃, mercury, and acid gases. Additionally, O’Brien & Gere has teamed with NOL-TEC Systems who has over 25 years of experience with bulk material handling and is recognized as a leader in the industry. Through extensive research and development performed jointly with NOL-TEC Systems, O'Brien & Gere has refined its DI - Duct Injection Technologies™ to include the following unique technical features: 

• On-site Milling - Through extensive research & development, O’Brien & Gere has developed a process for a practical and reliable on-site milling method that maximizes pollutant removal and reduces operating costs
• Dense-Phase Transport – Allows for long-range dry sorbent transport from remote silo storage.
• Uniform Flow – Dry aeration that is designed to maintain reliable and uniform flow of the sorbent that is injected into the flue gas.
• Enhanced Material Design – Sorbent flow splitter design allows for multi-port injection into the flue gas.
• Optimum Sorbent Distribution - CFD modeling of duct flow and pollutant concentration profile measurement ensures optimum sorbent distribution in flue gas.
  

• Low capital cost
• Minimal operation and maintenance personnel requirements
• Generation of a dry solid waste product
• Short implementation and startup time (6 months)

x-axis = Normalized Stoichiometric Ratio
y-axis = Percent of SO₂ Removed 

These performance levels have been demonstrated on a wide-range of units and fuels:
 

80 to 750 MW Units

Bituminous coal and PRB Blends

0.6 to 3.5 percent sulfur content

ESP

Baghouse

SCR

Scrubbers

Typical sorbent injection locations that are considered include:

Economizer Inlet (If Temp < 800F) Trona Air Heater Inlet (500 - 700F) Trona Air Heater Outlet (~300F) Trona & Hydrated Lime Brominated/Activated Carbon ESP Outlet/Scrubber Inlet Trona & Hydrated Lime