Nitrogen Enrichment for Low NOx Using Air Separation Membranes
Problem Statement: NOx emissions have severe health implications and therefore necessitate its
reduction from the human health standpoint. Exhaust Gas Recirculation (EGR) has proved to be a very effective tool to reduce in-cylinder temperature and hence NOx (NOx is a strong function of temperature). However, EGR has a lot of built-in adverse ramifications that negate its advantages in the long term. Some of them include- Combustion Contamination; Greater Control System Complexity; Application Variability; Materials and Durability; Decreased Fuel Economy; Lubricant Contamination and Increased PM emissions
Potential Solution: Nitrogen enrichment of intake air is an effective alternative to EGR without the imposed undesired consequences. This could be achieved using a mature technology which involves selective permeation of gases using an Air Separation Membrane (ASM). Oxygen-rich and nitrogen-rich streams are produced by passing air through a nonporous polymeric membrane. Introduction of inert diluents like nitrogen into a fuel-air mixture slow down the reaction rates of participating chemical species which eventually results in lower combustion temperatures and hence lower NOx. This process gives an added control parameter to reduce combustion temperature.
Results: A 70% NOx could be reduced with just an additional 2% of nitrogen enrichment of intake air. Research findings of this work have triggered more in-depth study of ASM and its applicability to various engine configurations. Extremely low NOx emissions can be realized by using membranes to improve air quality as well as meet EPA standards. Major engine manufacturers in India approached Argonne for potential collaboration and licensing agreements for our patent. The list of publications and patent awarded for nitrogen enrichment and variable air composition work are given below.
- Biruduganti, M., Gupta, S., Bihari, B., McConnell, S., Sekar, R., “Air Separation Membranes- An Alternative to EGR in Large Bore natural Gas Engines,” Journal of Engineering for Gas Turbines and Power GTP09-1189 (accepted for publication).
- Biruduganti, M., Gupta, S., and Sekar, R., "Low Temperature Combustion Using Nitrogen Enrichment to Mitigate NOx From Large Bore Natural Gas Fueled Engines," Journal of Engineering for Gas Turbines and Power (Vol.132, Iss.1).
- Biruduganti, M., Gupta, S., Bihari, B., and Sekar, R., “NOx Emissions Reduction Using Air Separation Membranes For Different Loads In Gas-Fired Engines,” IMECE2009-11363, ASME Congress Nov 13-19, 2009.
- Biruduganti, M., Gupta, S., Bihari, B., McConnell, S., Sekar, R., “Air Separation Membranes- An Alternative to EGR in Large Bore natural Gas Engines,” ASME ICES2009-76054.
- Biruduganti, M., Gupta, S., and Sekar, R., “Low Temperature Combustion Using Nitrogen Enrichment to Mitigate NOx from Large Bore Natural Gas-Fueled Engines,” ASMES2008-1616, Spring Technical Conference 2008.
- Biruduganti, M., Gupta, S., McConnell, S., and Sekar, R., “Performance of a Natural Gas Engine using Variable Air Composition,” PWR2005-50193 ASME Power Conference, Chicago, IL.
- Biruduganti, M., Gupta, S., McConnell, S., and Sekar, R., “Nitrogen Enriched Combustion of a Natural Gas Engine to Reduce NOx Emissions,” ICEF2004-843 Fall Technical Conference ASME 2004.
Munidhar Biruduganti, firstname.lastname@example.org; Sreenath B. Gupta, email@example.com