Effect of Fuel Preheating on Engine Characteristics of Waste Animal Fat-Oil Biodiesel in Compression Ignition Engine

Gokul Raghavendra Srinivasan; Ranjitha Jambulingam; Amel Gacem; Akil Ahmad; Javed Khan Bhutto; Krishna Kumar Yadav; Amine Mezni; Omar Khulaif R Alharbi; Saiful Islam; Yongtae Ahn; Byong-Hun Jeon

doi:10.3390/polym14183896

Effect of Fuel Preheating on Engine Characteristics of Waste Animal Fat-Oil Biodiesel in Compression Ignition Engine

Polymers (Basel). 2022 Sep 18;14(18):3896. doi: 10.3390/polym14183896.

Authors

Affiliations

¹ Research and Development Department, Steamax Envirocare Private Limited, Delhi 110058, India.
² CO2 Research and Green Technologies Centre, Vellore Institute of Technology, Vellore 632014, India.
³ Department of Physics, Faculty of Sciences, University 20 Août 1955, Skikda 21000, Algeria.
⁴ Chemistry Department, College of Science and Humanities, Prince Sattam Bin Abdulaziz University, Al-Kharj 11942, Saudi Arabia.
⁵ Department of Electrical Engineering, College of Engineering, King Khalid University, Abha 61421, Saudi Arabia.
⁶ Faculty of Science and Technology, Madhyanchal Professional University, Ratibad, Bhopal 462044, India.
⁷ Department of Chemistry, College of Science, Taif University, P.O. Box 11099, Taif 21944, Saudi Arabia.
⁸ Civil Engineering Department, College of Engineering, King Khalid University, Abha 61421, Saudi Arabia.
⁹ Department of Earth Resources & Environmental Engineering, Hanyang University, 222-Wangsimni-ro, Seongdong-gu, Seoul 04763, Korea.

Abstract

The present study aims at understanding the effects of fuel preheating on engine characteristics of waste animal fat-oil (WAF-O) biodiesel in a single-cylinder CI engine, with the preheating technique proposed as an effective means for enhancing the fuel properties. To understand the effects of the preheated fuel, the WAF-O biodiesel was preheated at 60, 80, 100 and 120 °C and tested along with neat diesel and unheated WAF-O biodiesel. For this purpose, biodiesel was produced from different animal wastes by means of KOH-assisted ethanol-based transesterification, reporting its maximum yield as 96.37 ± 1.8%, with significant distribution of unsaturated oleic acid, saturated palmitic acid and stearic acid. Upon evaluating its fuel characteristics as per ASTM D6751 standards, a rise in preheating temperature by 1 °C reduced the density and kinematic viscosity of WAF-O biodiesel by 0.383 kg/m3 and 0.025 mm2/s, respectively, and was explained by the weakening of intermolecular forces between its fatty acid ester molecules. Preheated samples reported superior combustion characteristics by exhibiting increased in-cylinder pressure (2.24%, on average) and heat release rates in addition to their shortened ignition delay (1−4 °CA). Furthermore, preheating of WAF-O biodiesel reduced its specific fuel consumption and increased its brake thermal efficiency by 7.86% (on average) and 9.23% (on average), respectively. However, higher preheating temperatures (>120 °C) resulted in increased fuel consumption owing to its varied flow characteristics. In addition to the changes in combustion characteristics, preheating WAF-O bio-diesel also resulted in reduced carbon monoxide, nitrous oxide and hydrocarbon emission by 13.88%, 7.21% and 26.94%, respectively, and increased carbon dioxide emission by 7.58%. Summing up, the enhancements in overall engine characteristics of preheated samples were accounted for by their improvised fuel injection characteristics due to their reduced density and viscosity, which ensured for their effective combustion.

Keywords: animal wastes; atomization and vaporization; engine characteristics; flow characteristics; fuel preheating; waste animal fat-oil biodiesel.

Grants and funding

The authors extend their appreciation to the Deanship of Scientific Research at King Khalid University, Saudi Arabia, for funding this work through the Research Group Program under Grant No.: RGP 2/91/43. Taif University Researchers Supporting Project number (TURSP-2020/28), Taif University, Taif, Saudi Arabia. This work was supported by the Mid-Career Research Program (grant number 2020R1A2C3004237) of the National Research Foundation of the Republic of Korea.