Combined effects of biodiesel–alcohol blends and exhaust gas recirculation on diesel engine performance, combustion, and emissions: an experimental study

Hussain F., Satgunam M. A. P., Panchal M., Rajak U., Ağbulut Ü.

Journal of Thermal Analysis and Calorimetry, cilt.1, sa.1, ss.1-11, 2026 (SCI-Expanded, Scopus)

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 1 Sayı: 1
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1007/s10973-026-16431-1
  • Dergi Adı: Journal of Thermal Analysis and Calorimetry
  • Derginin Tarandığı İndeksler: Academic Search Ultimate (EBSCO), Engineering Source (EBSCO), Scopus, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest), Aerospace Database, Science Citation Index Expanded (SCI-EXPANDED), Chemical Abstracts Core, Chimica, Compendex, Index Islamicus, INSPEC
  • Sayfa Sayıları: ss.1-11
  • İstanbul Ticaret Üniversitesi Adresli: Evet

Özet

Oxygenated fuel blends such as biodiesel and alcohol have attracted considerable attention as promising alternatives to conventional diesel fuel because of their potential to improve combustion and reduce exhaust emissions. However, the use of these fuels may increase nitrogen oxide (NOₓ) emissions owing to their higher oxygen content. Exhaust gas recirculation (EGR) is an effective method for reducing the NOₓ formation, although excessive EGR may adversely affect combustion efficiency and increase carbon monoxide (CO), hydrocarbon (HC), and smoke emissions. Therefore, this paper experimentally investigates the combined effects of waste cooking oil biodiesel (WCB), n-butanol, and different EGR rates on the performance, combustion, and emission characteristics of a single-cylinder compression ignition engine. The experiments were conducted using biodiesel blends (10–20%), n-butanol (10%), and EGR rates of 5%, 10%, and 15% under a constant compression ratio of 18:1, engine speed of 1500 rpm, and injection timing of 23° bTDC. Engine performance, combustion behavior, and exhaust emissions were evaluated at four engine loads (3, 6, 9, and 12 kg). Among the tested fuels, the DB10nB10 blend (80% diesel, 10% waste cooking oil biodiesel, and 10% n-butanol) exhibited favourable overall performance under the investigated operating conditions. The maximum brake thermal efficiency (BTE) of 30.79% was achieved with the DB10nB10 blend at 5% EGR, whereas the minimum BTE of 24.72% was obtained for neat diesel at 15% EGR under full-load conditions. Among the tested fuels, the DB10nB10 blend achieved a BSFC comparable to diesel, while the DWCB20 blend exhibited the highest BSFC under the investigated conditions. Although EGR effectively suppressed NOₓ formation, it simultaneously increased CO, HC, and smoke emissions because of the reduced oxygen availability during combustion. Overall, the combination of waste cooking oil biodiesel, n-butanol, and an optimized EGR rate provided an effective balance between engine efficiency and emission control. The findings demonstrate that the DB10nB10 blend coupled with moderate EGR has strong potential as a sustainable alternative fuel for improving diesel engine performance while reducing harmful exhaust emissions.

Oxygenated fuel blends such as biodiesel and alcohol have attracted considerable attention as promising alternatives to conventional diesel fuel because of their potential to improve combustion and reduce exhaust emissions. However, the use of these fuels may increase nitrogen oxide (NOₓ) emissions owing to their higher oxygen content. Exhaust gas recirculation (EGR) is an effective method for reducing the NOₓ formation, although excessive EGR may adversely affect combustion efficiency and increase carbon monoxide (CO), hydrocarbon (HC), and smoke emissions. Therefore, this paper experimentally investigates the combined effects of waste cooking oil biodiesel (WCB), n-butanol, and different EGR rates on the performance, combustion, and emission characteristics of a single-cylinder compression ignition engine. The experiments were conducted using biodiesel blends (10–20%), n-butanol (10%), and EGR rates of 5%, 10%, and 15% under a constant compression ratio of 18:1, engine speed of 1500 rpm, and injection timing of 23° bTDC. Engine performance, combustion behavior, and exhaust emissions were evaluated at four engine loads (3, 6, 9, and 12 kg). Among the tested fuels, the DB10nB10 blend (80% diesel, 10% waste cooking oil biodiesel, and 10% n-butanol) exhibited favourable overall performance under the investigated operating conditions. The maximum brake thermal efficiency (BTE) of 30.79% was achieved with the DB10nB10 blend at 5% EGR, whereas the minimum BTE of 24.72% was obtained for neat diesel at 15% EGR under full-load conditions. Among the tested fuels, the DB10nB10 blend achieved a BSFC comparable to diesel, while the DWCB20 blend exhibited the highest BSFC under the investigated conditions. Although EGR effectively suppressed NOₓ formation, it simultaneously increased CO, HC, and smoke emissions because of the reduced oxygen availability during combustion. Overall, the combination of waste cooking oil biodiesel, n-butanol, and an optimized EGR rate provided an effective balance between engine efficiency and emission control. The findings demonstrate that the DB10nB10 blend coupled with moderate EGR has strong potential as a sustainable alternative fuel for improving diesel engine performance while reducing harmful exhaust emissions.