Characterization of CNG induced transition regimes of reactivity-controlled-combustion of Madhuca longifolia biodiesel: An experimental case study

ABSTRACT

This study demonstrated the synergistic capability of split-injection techniques to achieve the better emission-performance-stability endeavor of a diesel engine operating under CNG-biodiesel reactivity-controlled compression ignition (RCCI) mode. CNG will enhance a diesel engine’s performances characteristics and reduce emissions when combined with a split injection technique. The biodiesel yielded from Mahua oil was characterized by Gas Chromatography-Mass spectrometry (GC-MS) analysis and classified biodiesel components. However, various physical properties were determined from GC-MS analytical responses. A systematic split-injection effort was tested for each pilot, and the main injection at different angles fueled with CNG-biodiesel to achieve the RCCI mode of combustion. The variance coefficient for indicated mean effective pressure (COV_IMEP) data demonstrated more reliable engine operation when fueling with CNG-biodiesel instead of fossil diesel. The analysis showed the highest exergy efficiency (30%) and the lowest brake specific energy consumption (8.64%) as performances characteristics, reported for RCCI mode of operation. This experimental study showed the lowest value of NOx, Soot, and UHC emissions under RCCI regimes. These values of NOx, Soot, and UHC emissions are 21.4%, 33.4%, 50% higher than plain biodiesel operation and 75.28%, 21.29%, and 83.87% better than plain fossil diesel operation. Therefore, the analysis showed the synergistic advantages of a CNG-biodiesel RCCI engine operating with the split injection mode to achieve higher efficiency and lower emission characteristics.

Graphical Abstract

KEYWORDS:

• CNG-Biodiesel
• split injection
• reactivity controlled compression ignition
• performance-emission-stability
• experimental approach

Acknowledgments

The authors gratefully acknowledge the kind support of the AICTE (Govt. of India) grant under the RPS projects entitled “Development of an artificial intelligence model to simulate the performance and emission characteristics of a diesel engine operating in dual fuel mode with biodiesel and CNG under various EGR strategies” under Grant No: 8023/RID/RPS-4/508 (POLICYIII) (NER)/2011-12. The first author of this article is an MHRD regular PhD scholar, gratefully acknowledge the kind support of MHRD and Mechanical Engineering Department of NIT Agartala.

Abbreviation

ASTM : American Society for Testing and Materials

BSEC: Brake Specific Energy Consumption

bTDC: Before Top-Dead Center

CN: Cetane Number

FAME: Fatty acid methyl esters

FD: Fossil Diesel

HOME: Honge oil methyl ester

HCCI: Homogeneous Charge Compression Ignition

HHV: Higher heating value

JOME: Jatropha oil methyl ester

LHV: Lower Heating value

LTC: Low-Temperature Combustion

MB: Mahua biodiesel

MOME: Mahua oil methyl ester

MPO: Mahua pyrolysis oil

RCCI: Reactivity Controlled Compression Ignition

VCR: Variable Compression Ratio

100MB: 100% Mahua Biodiesel energy share

100FD: 100% Fossil Diesel energy share

Additional information

Notes on contributors

Srijit Biswas

Srijit Biswas, PhD Scholar Of Mechanical Engineering Department of NIT Agartala, India having research interest on ICEngine, optimization and statistical analysis and CFD.

Dipankar Kakati

Dipankar Kakati, PhD Scholar Of Mechanical Engineering Department of NIT Agartala, India having research intereston IC Engine, optimization and statistical analysis and CFD.

Prasun Chakraborti

Prasun Chakraborti, Professor of Mechanical Engineering Department of NIT Agartala, India having research interest on CFD, optimization and statistical analysis.

Rahul Banerjee

Rahul Banerjee, Assistant Professor of Mechanical Engineering Department of NIT Agartala, India having research interest on IC Engine, CFD, optimization and statistical analysis.