Diesel DeNOx experiments using the SNCR process were performed by directly injecting NH3 into a simulated engine cylinder (966 cm3) for which a diesel fuelled combustion-driven flow reactor was designed by simulating diesel engine geometry, temperature profiles, aerodynamics and combustion products. A wide range of air/fuel mixtures (A/F=20∼45) were combusted for oxidizing diesel flue gas conditions where an initial NOx levels were 250~900 ppm and molar ratios (β=NH3/NOx) ranged from 0.5∼2.0 for NOx reduction tests. Effective NOx reduction occurred over a temperature range of 1100∼1350 K at cylinder injections where about 34% NOx reduction was achieved with β=1.5 and cylinder cooling at optimum flow conditions. The effects of simulated engine cylinder and exhaust parts, initial NOx levels, molar ratios and engine speeds on NOx reduction potential are discussed following temperature gradients and diesel engine environments. A staged injection by NH3 and diesel fuel additive is tested for further NOx reduction, and more discussed for practical implication.

Abstract
 1. Introduction
 2. Materials and methods
 3. Results and Discussion
  3.1. Temperature window and cylinder DeNOx capacity
  3.2. Effect of initial NOx and molar ratios
  3.3. Air flow rate (Engine speed)
  3.4. Staged injection by diesel fuel
 4. Conclusions
 References

• Chang-Mo Nam(Division of Health and Science, Yeungnam College of Science and Technology) Corresponding author
• Bernard M. Gibbs(School of Process, Environmental and Materials Engineering, University of Leeds)