Ultra-low emission combustion systems are game-changers in the fight against pollution. They use clever tricks like flameless burning and special catalysts to slash harmful emissions, making engines and power plants way cleaner.

These systems are crucial for meeting tough environmental rules and creating a greener future. From oxy-fuel combustion to advanced catalytic methods, they're pushing the boundaries of what's possible in clean energy production.

Advanced Combustion Techniques

Innovative Combustion Processes

• Flameless combustion operates at high temperatures with diluted reactants, resulting in reduced peak temperatures and uniform heat distribution
• MILD (Moderate or Intense Low-oxygen Dilution) combustion utilizes preheated and diluted oxidizers to achieve stable, low-emission combustion
  • Characterized by low temperature gradients and distributed reaction zones
  • Reduces thermal NOx formation by lowering peak flame temperatures
• Staged combustion divides the combustion process into multiple zones to control temperature and air-fuel ratios
  • Primary zone operates fuel-rich to limit NOx formation
  • Secondary zone completes combustion with excess air to reduce CO and unburned hydrocarbons

Advanced Oxidation Techniques

• Oxy-fuel combustion uses pure oxygen instead of air as the oxidizer
  • Eliminates nitrogen from the combustion process, reducing NOx emissions
  • Produces a concentrated CO2 stream, facilitating carbon capture and storage
  • Requires an air separation unit to produce pure oxygen, increasing operational costs
• Catalytic combustion employs catalysts to initiate and sustain combustion at lower temperatures
  • Reduces NOx formation by lowering reaction temperatures
  • Enables combustion of lean fuel mixtures, improving fuel efficiency
  • Commonly used in gas turbines and industrial furnaces

Emission Reduction Systems

Near-Zero Emission Technologies

• Near-zero emissions aim to minimize pollutant release to levels approaching zero
  • Combines multiple emission control technologies to achieve ultra-low emission levels
  • Requires continuous monitoring and advanced control systems to maintain performance
• Exhaust gas recirculation (EGR) recirculates a portion of exhaust gases back into the combustion chamber
  • Reduces oxygen concentration and lowers combustion temperatures, decreasing NOx formation
  • Can be implemented as internal or external EGR systems
  • Widely used in diesel engines and some gas turbine applications

Catalytic Reduction and Low-Emission Burners

• Selective catalytic reduction (SCR) uses a catalyst and a reducing agent (ammonia or urea) to convert NOx into nitrogen and water
  • Highly effective for NOx reduction, achieving up to 90% removal efficiency
  • Requires careful control of reagent injection and catalyst temperature for optimal performance
  • Commonly used in power plants, industrial boilers, and diesel engines
• Low NOx burners modify combustion conditions to minimize NOx formation
  • Staged air injection creates fuel-rich and fuel-lean zones within the combustion chamber
  • Flue gas recirculation reduces peak flame temperatures
  • Can be combined with other technologies (SCR, EGR) for further emission reductions