Inhibition effect of biodiesel on the formation of oxidized insoluble matter in diesel: characteristics and mechanism

ABSTRACT

To address the problem that oxidized insoluble matter in diesel is easily generated in the process of using, we proposed the idea of blending biodiesel into diesel to inhibit the formation of oxidized insoluble matter. We also studied the effect of the biodiesel blending ratio on the generation of oxidized insoluble matter and revealed the mechanism of biodiesel inhibiting the formation of diesel oxidized insoluble matter. According to the results, the color of the blended fuel became darker with the increase in oxidation time for B0–B100 blended fuel. The generation of oxidized insoluble matter during the oxidation of B0–B30 was obvious since the amount increased with the enhancement of biodiesel ratio. The formation phenomenon of oxidizing insoluble matter in diesel disappeared, however,when the addition ratio of biodiesel increased from 0%–30% to 40%–100%. Based on the results from Fourier transform infrared spectroscopy and gas chromatography-mass spectroscopy, the main component of oxidizing insoluble matter was tetralone. At low blending ratios, small molecule compounds such as alcohols, aldehydes, and ketones, were rapidly generated with the oxidation process of biodiesel, which maybe acted as precursors for formation of oxidation insoluble matter, thereby increasing the amount of oxidized insoluble matter. For high blending ratios, oxidized insoluble matter was gradually dissolved in biodiesel, because the polarity between biodiesel and oxidized insoluble matter was similar. The dielectric constant of biodiesel was 3.35, which indicated that biodiesel was a weak polar liquid. Meanwhile the oxidized insoluble matter was a polar substance, and its dielectric constant was 6.28–13.59. The results showed that the blending of biodiesel was expected to slow down the appearance of oxidized insoluble matter in diesel, thereby optimizing the performance of diesel and reducing the carbon emissions of diesel.

KEYWORDS:

• Diesel
• biodiesel
• oxidized insoluble matter
• polar
• blending fuel

Abbreviation

Abbreviation	=	Definition
B0	=	100% diesel
B10	=	10% biodiesel, 90% diesel
B20	=	20% biodiesel, 80% diesel
B30	=	30% biodiesel, 70% diesel
B40	=	40% biodiesel, 60% diesel
B50	=	50% biodiesel, 50% diesel
B60	=	60% biodiesel, 40% diesel
B70	=	70% biodiesel, 30% diesel
B80	=	80% biodiesel, 20% diesel
B90	=	90% biodiesel, 10% diesel
B100	=	100% biodiesel

Highlights

This article has the following highlights:

• The polarity of blended fuel and oxidized insolubles before and after oxidation was analyzed by measuring the dielectric constant.

• The oxidation fuel was analyzed by infrared spectrum and GCMS, and the effect of biodiesel blending ratio on the generation of oxidizing insoluble matter and revealed the mechanism of biodiesel inhibiting the formation of diesel oxidizing insoluble matter.

Disclosure statement

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Author contributions

P: Yi Lou: Conceptualization, Methodology, Data curation, Writing – original draft. Shuang Wang and Fashe Li: Writing – review & editing, Funding acquisition, Supervision, Project administration. Meng Sui: Resources. Renyi Chen: Formal analysis.

Additional information

Funding

This work was funded by the Yunnan Fundamental Research Projects (202201AS070036, 202201BE070001-047, 202401AS070111); National Natural Science Foundation of China (52166013); Yunnan Major Scientific and Technological Projects (202302AG050011, 202202AG050017, 202302AF080005).

Notes on contributors

Yi Lou

Yi Lou is a master’s student at the Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology. His research focuses on the efficient use of biomass energy.

Fashe Li

Shuang Wang is an associate professor at the Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology. Her research focuses on the efficient conversion and utilization of biomass energy.

Shuang Wang

Meng Sui is currently working at the Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology. His research focus is on the development and utilization of new energy.

Meng Sui

Fashe Li is a professor at the Faculty of Metallurgical and Energy Engineering, Kunming University of Science and Technology. His research focuses on the efficient conversion and utilization of biomass energy.

Renyi Chen

Renyi Chen is currently working at Grandblue Environment Co., Ltd. Her research focus is on the development and utilization of new energy.