Engine Speed–Dependent NOₓ Reduction Behavior of Safflower–Sunflower Biodiesel Blends in an SCR-Equipped Diesel Engine

Emre Horoz; Şükrü Ayhan Baydır

doi:10.64808/engineeringperspective.1894491

Engine Speed–Dependent NOₓ Reduction Behavior of Safflower–Sunflower Biodiesel Blends in an SCR-Equipped Diesel Engine

Abstract

In this study, the effects of safflower and sunflower biodiesel blends (B10 and B20) on diesel engine performance, combustion characteristics, and exhaust emissions were experimentally investigated, together with the catalytic performance of a diesel oxidation catalyst (DOC) and a selective catalytic reduction (SCR) system. Biodiesel was produced via transesterification and blended volumetrically with diesel fuel. Experiments were conducted on a single cylinder, direct injection, naturally aspirated diesel engine under full load conditions across an engine speed range of 1200 to 2800 rpm. Engine torque, brake power, brake specific fuel consumption (BSFC), in cylinder pressure, heat release rate (HRR), exhaust gas temperature (EGT), and regulated emissions including CO, HC, and NOx were analyzed. The overall experimental uncertainty of the measurement system was determined as 1.93% using the root sum square propagation method. Increasing biodiesel content led to slight reductions in engine performance due to lower heating value and altered spray characteristics. Compared to diesel, torque decreased by 1.80% and 3.24%, brake power by 0.62% and 1.75%, and BSFC increased by 2.91% and 6.14% for B10 and B20, respectively. Biodiesel blends reduced CO and HC emissions, with the DOC achieving conversion efficiencies exceeding 97% at engine speeds above 2000 rpm. Although biodiesel use alone increased NOx emissions, integration of the SCR system significantly enhanced emission control. At 2400 rpm, NOx conversion efficiencies reached 71.4%, 89.4%, and 93.1% for diesel, B10, and B20, respectively. EGT measurements confirmed that the progressive rise in SCR catalyst inlet temperature with increasing engine speed is the primary thermal mechanism governing speed dependent NOx conversion efficiency.

Keywords

Supporting Institution

This study was supported by Afyon Kocatepe University Scientific Research Projects Coordination Unit. Project Number: 23.FEN.BİL.36.

Project Number

This study was supported by Afyon Kocatepe University Sci-entific Research Projects Coordination Unit. Project Number: 23.FEN.BİL.36.

Thanks

This study was supported by Afyon Kocatepe University Scientific Research Projects Coordination Unit. Project Number: 23.FEN.BİL.36. The authors also express their sincere gratitude to Dr. Emrah Erçek for his contributions to the experimental studies.

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Details

Primary Language

English

Subjects

Internal Combustion Engines, Automotive Combustion and Fuel Engineering

Journal Section

Research Article

Authors

Emre Horoz
0000-0001-6776-7140
Türkiye

Şükrü Ayhan Baydır ^*
0000-0001-7136-7860
Türkiye

Publication Date

May 5, 2026

Submission Date

February 21, 2026

Acceptance Date

April 30, 2026

Published in Issue

Year 2026 Volume: 6 Number: 3

DOI

https://doi.org/10.64808/engineeringperspective.1894491

IZ

https://izlik.org/JA89BM49JL

Cite

RIS / Bibtex

APA

Horoz, E., & Baydır, Ş. A. (2026). Engine Speed–Dependent NOₓ Reduction Behavior of Safflower–Sunflower Biodiesel Blends in an SCR-Equipped Diesel Engine. Engineering Perspective, 6(3), 331-343. https://doi.org/10.64808/engineeringperspective.1894491

AMA

1.Horoz E, Baydır ŞA. Engine Speed–Dependent NOₓ Reduction Behavior of Safflower–Sunflower Biodiesel Blends in an SCR-Equipped Diesel Engine. engineeringperspective. 2026;6(3):331-343. doi:10.64808/engineeringperspective.1894491

Chicago

Horoz, Emre, and Şükrü Ayhan Baydır. 2026. “Engine Speed–Dependent NOₓ Reduction Behavior of Safflower–Sunflower Biodiesel Blends in an SCR-Equipped Diesel Engine”. Engineering Perspective 6 (3): 331-43. https://doi.org/10.64808/engineeringperspective.1894491.

EndNote

Horoz E, Baydır ŞA (May 1, 2026) Engine Speed–Dependent NOₓ Reduction Behavior of Safflower–Sunflower Biodiesel Blends in an SCR-Equipped Diesel Engine. Engineering Perspective 6 3 331–343.

IEEE

[1]E. Horoz and Ş. A. Baydır, “Engine Speed–Dependent NOₓ Reduction Behavior of Safflower–Sunflower Biodiesel Blends in an SCR-Equipped Diesel Engine”, engineeringperspective, vol. 6, no. 3, pp. 331–343, May 2026, doi: 10.64808/engineeringperspective.1894491.

ISNAD

Horoz, Emre - Baydır, Şükrü Ayhan. “Engine Speed–Dependent NOₓ Reduction Behavior of Safflower–Sunflower Biodiesel Blends in an SCR-Equipped Diesel Engine”. Engineering Perspective 6/3 (May 1, 2026): 331-343. https://doi.org/10.64808/engineeringperspective.1894491.

JAMA

1.Horoz E, Baydır ŞA. Engine Speed–Dependent NOₓ Reduction Behavior of Safflower–Sunflower Biodiesel Blends in an SCR-Equipped Diesel Engine. engineeringperspective. 2026;6:331–343.

MLA

Horoz, Emre, and Şükrü Ayhan Baydır. “Engine Speed–Dependent NOₓ Reduction Behavior of Safflower–Sunflower Biodiesel Blends in an SCR-Equipped Diesel Engine”. Engineering Perspective, vol. 6, no. 3, May 2026, pp. 331-43, doi:10.64808/engineeringperspective.1894491.

Vancouver

1.Emre Horoz, Şükrü Ayhan Baydır. Engine Speed–Dependent NOₓ Reduction Behavior of Safflower–Sunflower Biodiesel Blends in an SCR-Equipped Diesel Engine. engineeringperspective. 2026 May 1;6(3):331-43. doi:10.64808/engineeringperspective.1894491