Reducing NOx emission from palm biodiesel/diesel blends in CI engine: A comparative study of cetane improvement techniques through hydrogenation and fuel additives
Restricted accessResearch articleFirst published online October, 2025
Reducing NOx emission from palm biodiesel/diesel blends in CI engine: A comparative study of cetane improvement techniques through hydrogenation and fuel additives
In this study, the trans-esterification process prepared palm oil biodiesel and 20% biodiesel blended with diesel (PB20) by volume as test fuel. Unsaturated fatty acids are majorly influenced by biodiesel cetane number. This work examines two-fuel reformulation methods of fuel hydrogenation and addition of fuel additive di-tert-butyl peroxide (DTBP) to enhance the engine characteristics of a PB20 blend while maintaining emission control. A reactor (autoclave) was utilized for hydrogenating the palm biodiesel and examining the change in fuel composition using gas chromatography. DTBP is selected as the cetane enhancer and combined with PB20 at a 2000 ppm concentration. Tamson FBT equipment was utilized to evaluate the test fuel's filterability. The filterability, engine characteristics, and emissions were investigated for diesel (D0), PB20, HPB20, and PB20 + DTBP fuel blends in the compression ignition test engine. The FBT results reveal that PB20 and HPB20 have better filtration quality, which aligns with the standard requirements (ASTM D2068-14). An improved NOx (10.2%) and brake thermal efficiency (6.7%) are seen at engine full loads when using modified B20 fuels. The hydrocarbon, carbon monoxide, and smoke emissions decreased by 8.3%, 6%, and 10.14% compared to diesel fuel. Hence, partial hydrogenation has been a better approach to improving biodiesel trade-off features than DTBP addition.
BukkarapuKRKrishnasamyA. Biodiesel composition based machine learning approaches to predict engine fuel properties. Proc Inst Mech Eng Part D J Automob Eng Epub ahead of print 2023: 095440702311582.
2.
AnandKSharmaRPMehtaPS. Experimental investigations on combustion, performance, and emissions characteristics of a neat biodiesel-fuelled, turbocharged, direct injection diesel engine. Proc Inst Mech Eng Part D J Automob Eng2010; 224: 661–679.
3.
TiwariCDwivediGVermaTN. Sustainability evaluation, optimization and research dynamics of microalgae methyl ester in a research diesel engine. Proc Inst Mech Eng Part E J Process Mech Eng Epub ahead of print 2023: 095440892311623.
4.
YusoffMNAMZulkifliNWMSukimanNL, et al.Sustainability of palm biodiesel in transportation: a review on biofuel standard, policy and international collaboration between Malaysia and Colombia. BioEnergy Res2021; 14: 43–60.
5.
DeySReangNMDasPK, et al.A comprehensive study on prospects of economy, environment, and efficiency of palm oil biodiesel as a renewable fuel. J Clean Prod2021; 286: 124981.
6.
SivakrishnaTMadhuSSivakumarK. The effect of palm biodiesel fuel on the performance of automotive four stroke diesel engine. IOP Conf Ser Mater Sci Eng2019; 574: 012015.
7.
KesharvaniSDwivediGVermaTN, et al.The experimental investigation of a diesel engine using ternary blends of Algae biodiesel, ethanol and diesel fuels. Energies2022; 16: 229.
8.
IntarapongPJindavatCLuengnaruemitchaiA, et al.The transesterification of palm oil using KOH supported on bentonite in a continuous reactor. Int J Green Energy2014; 11: 987–1001.
9.
WadumesthrigeKSalleySONgKYS. Effects of partial hydrogenation, epoxidation, and hydroxylation on the fuel properties of fatty acid methyl esters. Fuel Process Technol2009; 90: 1292–1299.
10.
VedaramanNPuhanSNagarajanG, et al.Preparation of palm oil biodiesel and effect of Various additives on NOx emission reduction in B20: an experimental study. Int J Green Energy2011; 8: 383–397.
11.
SinghYPaliHSSinghNK, et al.Effect of nanoparticles as additives to the biofuels and their feasibility assessment on the engine performance and emission analysis—A review. Proc Inst Mech Eng Part E J Process Mech Eng2023; 237: 492–510.
12.
KrishnasamyAGuptaSKReitzRD. Prospective fuels for diesel low temperature combustion engine applications: a critical review. Int J Engine Res2021; 22: 2071–2106.
13.
LeeYHuhKY. Analysis of different modes of low temperature combustion by ultra-high EGR and modulated kinetics in a heavy duty diesel engine. Appl Therm Eng2014; 70: 776–787.
14.
KesharvaniSChhabraMDwivediG, et al.Execution and emission characteristics of automotive compression ignition engine powered by cerium oxide nanoparticles doped water diesel emulsion fuel. Fuel2023; 349: 128670.
15.
KumarMSJaikumarM. Studies on the effect of hydrogen induction on performance, emission and combustion behaviour of a WCO emulsion based dual fuel engine. Int J Hydrogen Energy2014; 39: 18440–18450.
16.
KumarCBLataDB. Effect of di-tert butyl peroxide (DTBP) on combustion parameters and NOx in dual fuel diesel engine with hydrogen as a secondary fuel. Int J Hydrogen Energy2021; 46: 4507–4525.
17.
GotoSLeeDWakaoY, et al.Development of an LPG DI diesel engine using cetane number enhancing additives. SAE Technical Paper 1999-01-3602, 1999. DOI: 10.4271/1999-01-3602.
18.
ZhengZJoshiUHeneinN, et al.Effect of cetane improver on combustion and emission characteristics of coal-derived sasol isomerized paraffinic kerosene in a single cylinder diesel engine. J Eng Gas Turbines PowerEpub ahead of print2015; 137: 071506. DOI: 10.1115/1.4029207.
19.
KumarCBLataDBMahtoD. Analysis of ignition delay by taking di-tertiary-butyl peroxide as an additive in a dual fuel diesel engine using hydrogen as a secondary fuel. Int J Hydrogen Energy2020; 45: 14806–14820.
20.
Örsİ. Experimental investigation of the cetane improver and bioethanol addition for the use of waste cooking oil biodiesel as an alternative fuel in diesel engines. J Brazilian Soc Mech Sci EngEpub ahead of print2020; 42: 177. DOI: 10.1007/s40430-020-2270-1.
21.
Adu-MensahDMeiDZuoL, et al.A review on partial hydrogenation of biodiesel and its influence on fuel properties. Fuel2019; 251: 660–668.
22.
ThunyaratchatanonCJitjamnongJLuengnaruemitchaiA, et al.Influence of Mg modifier on cis-trans selectivity in partial hydrogenation of biodiesel using different metal types. Appl Catal A Gen2016; 520: 170–177.
23.
MathewBCThangarajaJSivaramakrishnaA. Combustion, performance and emission characteristics of blends of methyl esters and modified methyl esters of karanja and waste cooking oil on a turbocharged CRDI engine. Clean Technol Environ Policy2019; 21: 1791–1807.
24.
NumwongNLuengnaruemitchaiAChollacoopN, et al.Effect of SiO2 pore size on partial hydrogenation of rapeseed oil-derived FAMEs. Appl Catal A Gen2012; 441–442: 72–78.
25.
McArdleSGirishSLeahyJJ, et al.Selective hydrogenation of sunflower oil over noble metal catalysts. J Mol Catal A Chem2011; 351: 179–187.
26.
Adu-MensahDMeiDZuoL, et al.A review on partial hydrogenation of biodiesel and its influence on fuel properties. Fuel2019; 251: 660–668.
27.
KesharvaniSDwivediG. Algae as a feedstock for biodiesel production in Indian perspective. Mater Today Proc2021; 47: 5873–5880.
28.
KesharvaniSDwivediGVermaTN. Optimization of performance characteristics in diesel engine utilizing Chlorella vulgaris fuel—a green approach towards sustainable development. Environ Sci Pollut Res. Epub ahead of print 5 May 2023; 1–27. DOI: 10.1007/s11356-023-27310-9.
29.
RehmanMKesharvaniSDwivediG. Numerical investigation of performance, combustion, and emission characteristics of various microalgae biodiesel on CI engine. Fuels2023; 4: 132–155.
30.
KomariahLNHadiahFAprianjayaF, et al.Biodiesel effects on fuel filter; assessment of clogging characteristics. J Phys Conf Ser2018; 1095: 012017.
31.
ThangamaniSSundaresanSNKannappanSS, et al.Impact of biodiesel and diesel blends on the fuel filter: a combined experimental and simulation study. Energy2021; 227: 120526.
32.
PrabuSSAsokanMAPrathibaS, et al.Effect of additives on performance, combustion and emission behavior of preheated palm oil/diesel blends in DI diesel engine. Renew Energy2018; 122: 196–205.
33.
MusthafaMMKumarTAMohanrajT, et al.A comparative study on performance, combustion and emission characteristics of diesel engine fuelled by biodiesel blends with and without an additive. Fuel2018; 225: 343–348.
34.
KesharvaniSVermaTNDwivediG. Computational analysis of chlorella protothecoides biofuels on engine combustion, performance and emission. Sustain Energy Technol Assessments2023; 55: 102972.
35.
ShehataMS. Emissions, performance and cylinder pressure of diesel engine fuelled by biodiesel fuel. Fuel2013; 112: 513–522.
36.
MusthafaBAsokanM. An experimental evaluation of cetane improving techniques for enhancing the performance and emission trade-off in diesel engine: A comparative study. Energy Environ Epub ahead of print 11 August 2023; 0958305X231193866. DOI: 10.1177/0958305X231193866.
37.
AsokanMASenthur PrabuSBadePKK, et al.Performance, combustion and emission characteristics of juliflora biodiesel fuelled DI diesel engine. Energy2019; 173: 883–892.
38.
ZhihaoMXiaoyuZJunfaD, et al.Study on emissions of a DI diesel engine fuelled with Pistacia Chinensis bunge seed biodiesel-diesel blends. Procedia Environ Sci2011; 11: 1078–1083.
39.
ZuoLWangJMeiD, et al.Experimental investigation on combustion and (regulated and unregulated) emissions performance of a common-rail diesel engine using partially hydrogenated biodiesel-ethanol-diesel ternary blend. Renew Energy2022; 185: 1272–1283.
40.
ZhongWPachiannanTHeZ, et al.Experimental study of ignition, lift-off length and emission characteristics of diesel/hydrogenated catalytic biodiesel blends. Appl Energy2019; 235: 641–652.
41.
AsokanMASenthur prabuSKameshS, et al.Performance, combustion and emission characteristics of diesel engine fuelled with papaya and watermelon seed oil bio-diesel/diesel blends. Energy2018; 145: 238–245.
42.
HeywoodJB. Internal Combustion Engine Fundamentals. New York: McGraw-Hill, 1988.
43.
MusthafaMM. Development of performance and emission characteristics on coated diesel engine fuelled by biodiesel with cetane number enhancing additive. Energy2017; 134: 234–239.
44.
JeyaseelanTChackoNNP, et al.Partial hydrogenation and hydrogen induction: a comparative study with B20 operation in a turbocharged CRDI diesel engine. Int J Hydrogen Energy2021; 46: 22659–22669.
45.
ChackoNJohnsonCVaradarajanP, et al.A comparative evaluation of cetane enhancing techniques for improving the smoke, NOx and BSFC trade-off in an automotive diesel engine. Fuel2021; 289: 119918. doi:10.1016/j.fuel.2020.119918.
46.
ThiruselvamKMurugapoopathiSRamachandranT, et al.Hydrogen-enriched palm biodiesel as a potential alternative fuel for diesel engines: investigating performance and emission characteristics and mitigation strategies for air pollutants. Int J Hydrogen Energy2023; 48: 30974–30984.
Supplementary Material
Please find the following supplemental material available below.
For Open Access articles published under a Creative Commons License, all supplemental material carries the same license as the article it is associated with.
For non-Open Access articles published, all supplemental material carries a non-exclusive license, and permission requests for re-use of supplemental material or any part of supplemental material shall be sent directly to the copyright owner as specified in the copyright notice associated with the article.
