Diesel Engine Performance, Emissions and Combustion Characteristics of Biodiesel and Its Blends Derived from Catalytic Pyrolysis of Waste Cooking Oil

Mohamed Mohamed; Chee-Keong Tan; Ali Fouda; Mohammed Saber Gad; Osayed Abu-Elyazeed; Abdel-Fatah Hashem

doi:10.3390/en13215708

Energies (Oct 2020)

Diesel Engine Performance, Emissions and Combustion Characteristics of Biodiesel and Its Blends Derived from Catalytic Pyrolysis of Waste Cooking Oil

Mohamed Mohamed,
Chee-Keong Tan,
Ali Fouda,
Mohammed Saber Gad,
Osayed Abu-Elyazeed,
Abdel-Fatah Hashem

Affiliations

Mohamed Mohamed: School of Engineering, University of South Wales, Pontypridd CF23 1DL, UK
Chee-Keong Tan: School of Engineering, University of South Wales, Pontypridd CF23 1DL, UK
Ali Fouda: Department of Mechanical Power Engineering, Faculty of Engineering, Mansoura University, Mansoura 35516, Egypt
Mohammed Saber Gad: Mechanical Engineering Department, Faculty of Engineering, Fayoum University, Fayoum 63514, Egypt
Osayed Abu-Elyazeed: Department of Mechanical Engineering, Faculty of Engineering, Helwan University, Mataria 11795, Egypt
Abdel-Fatah Hashem: Department of Mechanical Engineering, Faculty of Engineering, South Valley University, Qena 83523, Egypt

DOI: https://doi.org/10.3390/en13215708
Journal volume & issue: Vol. 13, no. 21
p. 5708

Abstract

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This paper first describes a slow catalytic pyrolysis process used for synthesizing biodiesel from waste cooking oil (WCO) as a feedstock. The influence of variations in the catalyst type (sodium hydroxide and potassium hydroxide), and catalyst concentration (0.5, 1.0, 3.0, 5.0, 7.0 and 10.0% by weight) on both the pyrolysis temperature range and biodiesel yield were investigated. The results suggested that sodium hydroxide (NaOH) was more effective than potassium hydroxide (KOH) as catalysts and that the highest yield (around 70 wt.%) was observed for a NaOH concentration of about 1 wt.% The resultant pyrolysis temperature range was also significantly lower for NaOH catalyst, thus suggesting overall lower energy consumption. Compared to conventional diesel, the synthesized biodiesel exhibited relatively similar physical properties and calorific value. The biodiesel was subsequently blended with diesel fuel in different blend ratios of 0, 20, 40, 60, 80 and 100% by volume of biodiesel and were later tested in a compression ignition engine. Brake thermal efficiency and specific fuel consumption were observed to be worse with biodiesel fuel blends particularly at higher engine load above 50%. However, NOx emission generally decreased with increasing blend ratio across all engine load, with greater reduction observed at higher engine load. Similar observation can also be concluded for CO emission. In contrast, lower hydrocarbon (HC) emission from the biodiesel fuel blends was only observed for blend ratios no higher than 40%. Particulate emission from the biodiesel fuel blends did not pose an issue given its comparable smoke opacity to diesel observed during the engine test. The in-cylinder peak pressures, temperature and heat release rate of biodiesel fuel blends were lower than diesel. Overall, biodiesel fuel blends exhibited shorter ignition delays when compared to diesel fuel.

Published in Energies

ISSN: 1996-1073 (Online)
Publisher: MDPI AG
Country of publisher: Switzerland
LCC subjects: Technology
Website: http://www.mdpi.com/journal/energies

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