Effects of oxidation degree and antioxidant addition on the carbon deposition tendency of jatropha biodiesel

ABSTRACT

The residual carbon value and existent gum content were used to evaluate the carbon deposition tendency of the jatropha biodiesel with different oxidation degrees. The chemical components of residual carbon and existent gum of the jatropha biodiesel were analyzed before and after oxidation by Gas chromatography-mass spectrometry (GC-MS) and infrared spectrometer. The results showed that in the short-term oxidation process, both the residual carbon and existent gum content decreased first, and then increased with oxidation time. In the long-term oxidation process, these two indicators monotonically increased with oxidation time. The residual carbon and existent gum content increased from 1140 mg/100 mL to 11,300 mg/100 mL and from 0.0272% to 0.277%, respectively. After oxidation, the aromatic compounds in the residual carbon as well as the content in the existent gum such as cyclic ether, carboxylic acid, ketone carbonyl and some fat-soluble impurities significantly increased. The addition of antioxidants showed inhibitive effect on the formation of carbon residue and existent gum. Butylated hydroxytoluene reduced the gum content by 58.3%, and methyl gallate reduced the residual carbon value by 21.1%. These findings prove that the antioxidants can effectively inhibit the auto-oxidation of biodiesel, and thus, reduce the carbon deposition tendency of biodiesel.

KEYWORDS:

• Biodiesel
• oxidation
• carbon deposition
• existent gum
• carbon residue
• antioxidant

Abbreviations

MG Methyl gallateBHT Butylated hydroxytolueneDTBHQ Di-tert-butylhydroquinonePPD p-PhenylenediamineGC-MS Gas chromatography-mass spectrometryCO Carbon monoxidePG Propyl gallateTBHQ Tert-butyl hydroquinoneOPD o-PhenylenediamineFTIR Fourier transform infrared spectrometerB10 Diesel-biodiesel blend containing 10% biodiesel in volumePM Particulate matter

Disclosure statement

No potential conflict of interest was reported by the authors.

Data availability statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China (52166013); Yunnan Fundamental Research Projects (202101AS070115)

Notes on contributors

Zhenyu Dong

Zhenyu Dong is a MEng researcher in Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, China. His research interests mainly about combustion and emission control of biomass fuel.

Fashe Li

Fashe Li, PhD, is Professor at Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, China. His research interests mainly focus on short process-efficient preparation of biomass fuel, biomass fuel performance regulation and optimization of biomass fuel, efficient clean combustion technology of liquid fuel. He is author of 143 publications, 3 books and 23 patents and has participated in several projects and contracts with Industry and academia.

Huicong Zhang

Huicong Zhang is Lecturer at Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, China. Dr Zhang's current research focuses on biomass energy conversion and utilization, pollutant emissions and control. He has published 17 academic papers, including 9 papers published by the first/corresponding author in the Journal of Hazardous Materials, Fuel and other authoritative academic journals (332 cites).

Yaozong Duan

Yaozong Duan is an assistant professor at Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, China. He received his PhD degree in Power Engineering and Engineering Thermophysics from Shanghai Jiao Tong University in June 2022. Dr. Duan's current research focuses on fuel spray dynamics, combustion chemistry, theoretical chemical kinetics for low-carbon fuels. He has published more than 20 journal papers in these areas.

Zhongjin Zhao

Zhongjin Zhao is a MEng researcher in Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, China. His research interests mainly about optimization of thermophysical parameters of biodiesel.

Yuzeng Zheng

Yuzeng Zheng is a MEng researcher in Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, China. His research interests mainly about optimization of lubrication performance of biodiesel.

Wenchao Wang

Wenchao Wang is a PhD researcher in Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology, China. His research interests mainly about Conversion and application of bioenergy. Wenchao Wang works have been published in prestigious journals, such as Energy, Fuel, and Renewable Energy.