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Renewable fuels have an important role to create sustainable energy systems. In this paper the focus is on biodiesel, which is produced from vegetable oils or animal fats. Today biodiesel is mostly used as a drop-in fuel, mixed into conventional diesel fuels to reduce their environmental impact. Low quality drop-in fuel can lead to deposits throughout the fuel systems of heavy duty vehicles. In a previous study fuel filters from the field were collected and analyzed with the objective to determine the main components responsible for fuel filter plugging. The identified compounds were constituents of soft particles. In the current study, the focus was on metal carboxylates since these have been found to be one of the components of the soft particles and associated with other engine malfunctions as well. Hence the measurement of metal carboxylates in the fuel is important for future studies regarding the fuel’s effect on engines.

Biofuel can enable a sustainable transport solution and lower greenhouse gas emissions compared to standard fuels. This study focuses on biodiesel, implemented in the easiest way as drop in fuel. When mixing biodiesel into diesel one can run into problems with solubility causing contaminants precipitating out as insolubilities. These insolubilities, also called soft particles, can cause problems such as internal injector deposits and nozzle fouling. One way to overcome the problem of soft particles is by filtration. It is thus of great interest to be able to quantify fuel filters’ ability to intercept soft particles. The aim of this study is to test different fuel filters for heavy-duty engines and their ability to filter out synthetic soft particles. A custom-built fuel filter rig is presented, together with some of its general design requirements. For evaluation of the efficiency of the filters, fuel samples were taken before and after the filters.

Renewable fuels are essential in the field of heavy duty transportation if we are to reach a fossil-free society in the foreseeable future. However renewable diesel fuels based on fatty acid methyl ester (FAME) might face problems with degradation and with cold flow properties. From the perspective of an engine, this may cause problems in the fuel injection system, such as fuel filter clogging and injector deposits. These phenomena, especially fuel filter clogging, can be connected to gel-like soft particles, which could originate from degradation products as well as from byproducts created during biodiesel refining. In this study, soft particles from the degradation of bio-based diesel fuel were examined. The tested fuels included hydrogenated vegetable oils (HVO), rapeseed methyl ester (RME) and 10% blend of rapeseed methyl ester with standard diesel (B10).

The global demand for decreased emission from engines and increased efficiency drives manufactures to develop more advanced fuel injection systems. Today's compression-ignited engines use common rail systems with high injection pressures and fuel injector nozzles with small orifice diameters. These systems are highly sensitive to small changes in orifice diameters since these could lead to deteriorations in spray characteristics, thus reducing engine performance and increasing emissions. Phenomena that could create problems include nozzle fouling caused by metal carboxylates or biofuels. The problems increase with extended use of biofuels. This paper reports on an experimental study of nozzle hole fouling performed on a single-cylinder engine. The aim was to identify if the solubility of the fuel has an effect on deposit build-up and, thus, the reduction in fuelling with associated torque loss, and if there is a probability of regenerating the contaminated injectors.

In order to mitigate the effect of fossil fuels on global warming, biodiesel is used as drop in fuel. However, in the mixture of biodiesel and diesel, soft particles may form. These soft particles are organic compounds, which can originate from the production and degradation of biodiesel. Further when fuel is mixed with unwanted contaminants such as engine oil the amount soft particles can increase. The presence of these particles can cause malfunction in the fuel system of the engine, such as nozzle fouling, internal diesel injector deposits (IDID) or fuel filter plugging. Soft particles and the mechanism of their formation is curtail to understand in order to study and prevent their effects on the fuel system. This paper focuses on one type of soft particles, which are metal soaps. More precisely on the role of the short chain fatty acids (SCFA) during their formation. In order to do so, aged and unaged B10 was studied.

Heavy-duty transportation accounts for significant part of the greenhouse gas emissions. Currently the most common powertrain for long-haul trucks is compression-ignited engines. In order to reduce the greenhouse gas emissions of these engines, renewable fuels, such as biodiesel can be used. Today biodiesel is used as a drop-in fuel, however when biodiesel is mixed with conventional diesel, soft particles may form. Soft particles have been identified as a mixture of insoluble impurities and degradation products in the fuel. These soft particles can lead to deposits in the injection and fuel filtration system, leading to reduced engine performance. In this paper, zinc-neodecanoate and soft particles from the degradation of biodiesel is studied. In both cases, the emphasis is on soap type contaminants. Zinc-neodecanoate has shown to lead to nozzle fouling, while soft particles from degradation of biodiesel have been found in diesel fuel filters.

Fuel filters serve as a safety belt for modern compression ignition engines. To meet the requirements from environmental regulations these engines use the common rail injection system, which is highly susceptible to contamination from the fuel. Furthermore, the public awareness towards global warming is raising the need for renewable fuels such as biodiesel. An increased fuel variety brings a higher requirement for fuel filters as well. To better understand the process of filtration, awareness of the different possible contaminants from the field is needed. This study used several chemical characterization techniques to examine the deposits from plugged fuel filters collected from the field. The vehicle was run with a biodiesel blend available on the market.