Effects of Aging on Carbon Residue of Biodiesel Fuels
Open Access
- Author:
- Terbovich, Andrew George
- Area of Honors:
- Environmental Systems Engineering
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Andre Louis Boehman, Thesis Supervisor
Andre Louis Boehman, Thesis Supervisor
Mark Stephen Klima, Thesis Honors Advisor - Keywords:
- biodiesel
carbon residue
ramsbottom test
fuel coking
fuel oxidation
micro method
conradson - Abstract:
- Biodiesel fuels have long been known to experience changes in fuel characteristics and quality as it ages and oxidizes. Due to several chemical factors of the fuel, notably the unsaturated nature of the hydrocarbon chains, this oxidation readily takes place under typical storage conditions of the fuel. As a large amount of biodiesel fuel is already present in our fuel supply and its usage is poised to grow in the near future, it is important to have a full understanding of the fuel’s lifespan and storability. Focusing specifically on the effects of oxidation on carbon deposition characteristics of biodiesel fuels, two experiments were carried out utilizing the Ramsbottom test to determine carbon residue. The first tested several types of biodiesel fuels and standard ultra low-sulfur diesel fuel before and after a storage period of several months. During the storage period, the fuels were stored at room temperature in small glass vials with adequate air space for autoxidation. The results of this testing did not show a conclusive change in the Ramsbottom carbon residue of any of the fuels tested, however the diesel fuel did have a significant decrease in carbon residue. The biodiesel did generate lower levels of carbon residue than the diesel fuel. The second experiment carried out tested a specific biodiesel fuel over time as it oxidized. A high-quality, commercially-made biodiesel fuel with an antioxidant additive package was tested to simulate what a consumer would purchase from a large manufacturer. The fuel was artificially oxidized in a heated sealed reaction chamber with a constant flow of oxygen through the device. The fuel was tested before, during, and after a 24 hour period in the reaction chamber. Testing results showed that the fuel did not experience any significant changes in Ramsbottom carbon residue. This indicates that long-term storage would not create a problem for carbon depositions when using a high-quality, chemically treated biodiesel fuel.