Combined Impact of Biodiesel and Exhaust Gas Recirculation on NOx Emissions

Abstract When converting diesel engines to run on natural gas on the gas-diesel cycle, additional problems arise associated with the high thermal stress of the exhaust valves and valve seats at high loads and engine speeds. There is also an increase in NOx emissions due to higher combustion temperatures of natural gas. One of the ways to improve the economic and environmental performance of engines operating on a gas-diesel cycle with a lean air-fuel mixture is to optimize the combustion of the air-fuel mixture by using an exhaust gas recirculation system (EGR). The principle of operation of this system is as follows: exhaust gas entering the intake manifold and further into the combustion chamber reduces the oxygen concentration in the air-fuel mixture, which leads to a dilution effect and, accordingly, to a decrease in combustion temperature and a decrease in NOx content. In order to study the influence of EGR on the dual-fuel gas and diesel engine parameters in the AVL Boost software package, a computer model of the existing 6ChN13/15 engine was developed. A low-pressure EGR system with an exhaust gas cooler was simulated on this engine. Values of NOx emissions, brake specific fuel consumption (BSFC) and brake efficiency have been obtained at different recirculation rate by calculation method. These values allow to estimate the feasibility of using a cooled EGR in a natural gas-fueled diesel engine.

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Effect of Exhaust Gas Recirculation and Isobutanol Additive on Biodiesel Fuelled Diesel Engine for the Reduction of NOx Emissions

International Journal of Advanced Science and Technology ◽

10.14257/ijast.2016.92.03 ◽

2016 ◽

Vol 92 ◽

pp. 17-24

Author(s):

S. Kirankumar ◽

K. Apparao ◽

R. Nagendrababu

Keyword(s):

Diesel Engine ◽

Exhaust Gas Recirculation ◽

Nox Emissions ◽

Exhaust Gas ◽

Reduction Of Nox ◽

Gas Recirculation

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Biodiesel Combustion and Emissions in Engines Using Modern Common-Rail Fuel Injection Systems

Volume 3: Combustion Science and Engineering ◽

10.1115/imece2008-69234 ◽

2008 ◽

Author(s):

Prashanth K. Karra ◽

Matthias K. Veltman ◽

Song-Charng Kong

Keyword(s):

Fuel Injection ◽

Injection Pressure ◽

Exhaust Gas Recirculation ◽

Common Rail ◽

Injection System ◽

Injection Timing ◽

Fuel Injection System ◽

Nox Emissions ◽

Exhaust Gas ◽

Gas Recirculation

This study performed experimental testing of a multi-cylinder diesel engine using different blends of biodiesel and diesel fuel. The engine used an electronically-controlled common-rail fuel injection system to achieve a high injection pressure. The operating parameters that were investigated included the injection pressure, injection timing, and exhaust gas recirculation rate. Results showed that biodiesel generally reduced soot emissions and increased NOx emissions. The increase in NOx emissions was not due to the injection timing shift when biodiesel was used because the present fuel injection system was able to give the same fuel injection timing. At high exhaust gas recirculation rates, emissions using regular diesel and 20% biodiesel blends are very similar while 100% biodiesel produces relatively different emission levels. Therefore, the increase in NOx emissions may not be a concern when 20% biodiesel blends are used with high exhaust gas recirculation rates in order to achieve low temperature combustion conditions.

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