An investigation of the degradation of biodiesel blends in a heavy-duty diesel engine test
2022-01-0628
03/29/2022
- Content
- One way to reduce carbon dioxide emissions from the current heavy-duty vehicles fleet is to replace fossil fuel with renewable fuel. This can be done by blending into the standard diesel fuel with so-called drop-in fuels. However, problems such as insoluble impurities may arise when the fuels are mixed. These precipitates, known as soft particles, can cause deposits in the fuel system, i.e., injectors and fuel filters, reducing the engine´s performance. The most used drop-in fuel today is biodiesel which is blended to different levels. To better understand how soft particles are formed in the vehicle´s fuel system, the degradation of biodiesel blends in the engine has been investigated. This study explores biodiesel blends´ degradation process by comparing the incoming fuel with the return fuel from a modern diesel engine to investigate how the fuel is affected by this process. The engine was run using different blends of biodiesel fuel. To investigate the degradation of the biodiesel, engine tests at low, medium, and high torque with two engine speeds were performed. Fuel samples were collected before and after the test for comparison. The tested fuels were examined with different analytical techniques. i.e., Rancimat, Fourier-transform infrared spectroscopy, Inductively coupled plasma atomic emission spectroscopy, and chromatography-mass spectrometry. A filtration test method was developed to collect the soft particles from the tested fuels. The results did not show any signs of degradation in the tested fuels after the engine test. According to our expectations, the fuels showed better results in oxidation stability with Rancimat analysis after the engine test. The acid number showed no change between fuels before and after the engine. No correlation with different torque and engine speed when running the engine could be seen. Almost no variation in the filterability was seen for low biodiesel blends. Higher blends showed high variations, where B30 showed the highest. This could indicate that B30 is the most sensitive fuel.
- Citation
- Pach, M., Hittig, H., Ramden, A., and Bernemyr, H., "An investigation of the degradation of biodiesel blends in a heavy-duty diesel engine test ," SAE Technical Paper 2022-01-0628, 2022, .