The increasing fuel demand, decreasing natural reserves and environmental consciousness have together led to the testing and implementation of new fuels and blending components for internal combustion engines. Biofuels are very commonly added to fossil fuels, most commonly ethanol to gasoline and FAME to diesel. Harmonizing their properties with the engines is a great challenge for the automotive and oil industry. The increasing demand for diesel and decreasing demand for gasoline in Europe raised the question of how it is possible to increase the amount of bio extenders in diesel. Butanol as a potential second generation biofuel could be a future option for blending with diesel. A comprehensive analytical and empirical testing sequence was carried out in the MOL Group's Product Development laboratories to check the application properties of butanol-diesel mixtures. More than 20 chemical and physical parameters of blends were tested regarding flash point, cetane number, viscosity and cold filter plugging point (CFPP). The effects of butanol blending were also tested on power, fuel consumption and injector cleanness. Based on our results it can be said that low butanol blends (up to 5vol% butanol content) appear to be a good alternative for compression ignition engine utilization: they hold the cetane number limits without extra cetane booster additivisation; they allow nearly the same fuel consumption level along with a considerable increase in injector cleanness. The test results support that the utilization of butanol as a diesel extender could be very advantageous, if the difficulties of flash point reduction can be handled in the logistical chain.

Increasing fuel demand, decreasing natural reserves and environmental consciousness have together led to testing and implementing new fuels and blending components of compression ignition engines. Biofuels are very commonly added to fossil fuels, mostly ethanol to gasoline and FAME to diesel. Harmonizing their properties with engines is a great challenge for automotive and oil industry. Increasing demand for diesel oil in Europe raised the question about the possibility of increasing the amount of bio extenders. There were and certainly there are a number of experiments aimed at substituting or blending diesel with other fuels. One group of such fuels makes bioethanol– biodiesel–diesel oil mixtures. The paper proposes a global overview on literature and presents the obtained results. The article explores the possibility of using bioethanol–biodiesel–diesel oil mixtures in vehicles and agricultural compression ignition engines. The main aspect of researches was to find blends substitutable for compression ignition engines. Investigations were made to determine the maximum volume of a renewable part thus reaching the same or similar power output with lowering emissions. The received results were used for environmental and economical investigations. The valorisation of the results shows that bioethanol–biodiesel–diesel blends fulfil the cetane number, viscosity and lubricity requirements for standard diesel. Practical measurements and engine tests show that the utilization of a new fuel decreases emissions from the engine. The results of agricultural feedstock calculation indicate that in Hungary the biofuel part of the investigated fuels can be produced from an overflow.

Natural gas (NG) is favored for transportation due to its availability and lower CO₂ emissions than fossil fuels, despite drawbacks like poor lean combustion ability and slow burning. According to a few recent studies, using hydrogen (H₂) alongside NG and diesel in Tri-fuel mode addresses these drawbacks while enhancing efficiency and reducing emissions, making it a promising option for diesel engines. Due to the importance and novelty of this, the continuation of ongoing research, and insufficient literature studies on HNG–diesel engine emissions that are considered helpful to researchers, this research has been conducted. This review summarizes the recent research on the HNG–diesel Tri-fuel engines utilizing hydrogen-enriched natural gas (HNG). The research methodology involved summarizing the effect of engine design, operating conditions, fuel mixing ratios and supplying techniques on the CO, CO₂, NO_x and HC emissions separately. Previous studies show that using natural gas with diesel increases CO and HC emissions while decreasing NO_x and CO₂ compared to pure diesel. However, using hydrogen with diesel reduces CO, CO₂, and HC emissions but increases NO_x. On the other hand, HNG–diesel fuel mode effectively mitigates the disadvantages of using these fuels separately, resulting in decreased emissions of CO, CO₂, HC, and NO_x. The inclusion of hydrogen improves combustion efficiency, reduces ignition delay, and enhances heat release and in-cylinder pressure. Additionally, operational parameters such as engine power, speed, load, air–fuel ratio, compression ratio, and injection parameters directly affect emissions in HNG–diesel Tri-fuel engines. Overall, the Tri-fuel approach offers promising emissions benefits compared to using natural gas or hydrogen separately as dual-fuels.

This article aims to investigate the development path of fuel development. From fossil fuel to alternative fuel technologies and drivetrains. Various technologies have been emerged in the recent years in the transport sector in order to facilitate the decrease of environmental pollution of the road vehicle.

Modern Diesel engines have complex exhaust gas recirculation (EGR) systems. Due to the high temperatures, it is a typical issue to measure EGR mass flow rates in these complex control systems. Therefore, it is expedient to estimate it. Several sensed values can help the estimation: the fresh air mass flow rate, the fuel consumption, pressures, temperatures and mass fractions in the air path system. In most of the articles, the EGR mass flow rate estimation is done by the pressures. However, gas composition based models usually would be better for control aims. In this paper, nine EGR estimation methods will be presented: an important outcome is to present the required sensor architectures and estimation challenges. The comparison will be made by measurement results both in stationary operation points and transient cycles. The estimated EGR mass flow rates will be evaluated by verification conditions. The results will prove that the intake and exhaust side oxygen sensors can give verifiable signals for EGR mass flow rate estimation. In contrast, the applied fresh air mass flow rate and the nitrogen-oxide signals are not accurate enough to provide verifiable EGR mass flow rates in every operating condition. The effects of sensor inaccuracies will also be considered.