Research

Earth, Atmosphere & Environment Sciences

Title :

Assessment of Stability Limits and NOx Emissions of Non-premixed Ammonia-Hydrogen Air Flames

Area of research :

Earth, Atmosphere & Environment Sciences

Focus area :

Combustion Engineering and Environmental Science

Principal Investigator :

Dr. Rajesh Sadanandan, Indian Institute of Space Science and Technology, Thiruvanthapuram, Kerala (695547)

Timeline Start Year :

2023

Timeline End Year :

2025

Contact info :

Details

Executive Summary :

This study aims to investigate the flame stability limits and pollutant emission of ammonia-hydrogen blends in a non-premixed burner in an atmospheric laboratory-scale combustor for a wide range of hydrogen fractions. The long-term goal is to develop models that can accurately predict the different combustion phenomena associated with NH3-H2 mixtures undergoing swirl combustion. The burner, running on NH3-H2, has to be optimized for ultra-low pollutant emissions over a wide range of operating conditions. The current state of research/technology in this topic requires further research, especially in flame dynamics and chemistry. While some studies reported on the flame stability limits and pollutant emissions for ammonia-methane and ammonia-hydrogen swirl premixed flames, no studies focused on the stability or combustion characteristics of NH3-H2 non-premixed flames at different levels of H2 enrichment. The proposed activities include conducting experiments on a non-premixed swirl burner IIST-GS1 developed in situ at IIST, which promotes intense mixing between fresh fuel and air with recirculating burned gases. Multiple measurement or diagnostic techniques will be employed, including flame luminosity, probe measurements, exhaust gas measurements, laser absorption spectroscopy, chemiluminescence, and planar laser induced fluorescence. Numerical simulations will be conducted to investigate the influence of H2-addition on NOx formation, extinction strain rates, and flame stability. The strain rate is of great importance concerning turbulent mixing by enhancing or suppressing scalar gradients, and it can be used to predict local extinction and re-ignition effects in non-premixed turbulent combustion. In conclusion, this study aims to address the challenges of hydrogen production, ammonia NH3, and NH2 combustion in a non-premixed burner in an atmospheric laboratory-scale combustor.

Co-PI:

Dr. Satheesh K, Indian Institute of Space Science and Technology, Thiruvanthapuram, Kerala (695547)

Total Budget (INR):

9,30,000

Organizations involved