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Ducted Fuel Injection for Soot Reduction

Sandia National Laboratories

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PDF Document PublicationMarket Sheet (1,233 KB)

Technology Marketing Summary

Sandia National Laboratories has developed ducted fuel injection technology for the reduction of soot and other EPA regulated emissions in direct-injection engines. Typical direct-injection engines, such as diesel engines, can produce soot due to fuel-rich combustion conditions. Filters and catalytic converters are currently used to reduce soot and harmful emissions, but these systems are expensive, large, complex, and they penalize engine efficiency. Sandia’s ducted fuel injection technology reduces soot at the point of combustion, thereby reducing the need for these after-treatment devices and their associated costs.


Sandia’s mechanical solution forces each fuel spray from the fuel injector through a small duct located within the combustion chamber. Oxygen is drawn into each duct due to the pressure field established during fuel injection, and the ensuing enhanced turbulent mixing creates an optimized mixture of fuel and oxygen. The more-homogeneous fuel mixture is then released from the duct into the combustion chamber where it ignites—eliminating soot that results from unevenly mixed, fuel-rich combustion. Sandia’s ducted fuel injection technology could be a key technology for future engines because it is an effective, conceptually simple approach for lowering soot and other emissions, as well as potentially improving combustion efficiency. It also has potential applications in spark ignition engines, gas turbine engines, industrial boilers, and refinery flaring.

  • Decreases emissions and potentially other harmful emissions
  • Reduces engine system costs
  • Increases engine efficiency
  • Tolerant to a wide variety of fuels
Applications and Industries
  • Diesel (compression ignition) engines
  • Spark ignition engines
  • Gas turbine engines
  • Industrial burners/boilers
  • Wellhead/refinery flaring
Patents and Patent Applications
ID Number
Title and Abstract
Primary Lab
Patent 9,909,549
Ducted fuel injection
Various technologies presented herein relate to enhancing mixing inside a combustion chamber to form one or more locally premixed mixtures comprising fuel and charge-gas with low peak fuel to charge-gas ratios to enable minimal, or no, generation of soot and other undesired emissions during ignition and subsequent combustion of the locally premixed mixtures. To enable sufficient mixing of the fuel and charge-gas, a jet of fuel can be directed to pass through a bore of a duct causing charge-gas to be drawn into the bore creating turbulence to mix the fuel and the drawn charge-gas. The duct can be located proximate to an opening in a tip of a fuel injector. The duct can comprise of one or more holes along its length to enable charge-gas to be drawn into the bore, and further, the duct can cool the fuel and/or charge-gas prior to combustion.
Sandia National Laboratories 03/06/2018
Technology Status
Technology IDDevelopment StageAvailabilityPublishedLast Updated
SD#13289Prototype - Sandia estimates this technology at a Technology Readiness Level 3. Key elements have been demonstrated in a laboratory environment.Available07/05/201807/05/2018

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