The paper substantiates the need for the use of biofuels in diesel engines. It is shown that the choice for diesel alternative biofuel with a perspective should be carried out in accordance with the design features of the engine and during its primary tests. The paper studies such eco-friendly energy sources as methanol, ethanol and methyl ether of rapeseed oil. Methanol, ethanol and methyl ester of rapeseed oil potentially lead to some solutions to environmental problems, as for their production, there are quite abundant resources and these energy sources are characterized by relatively low emissions of harmful substances when burning. The ways of bioethanol production from various raw materials and the process of rapeseed oil methanolysis are considered. Experimental studies of biodiesel operating on alcohol-fuel emulsions, methanol and methyl ether of rapeseed oil were carried out.

The paper presents the results of studies of the volume content and mass concentration of nitrogen oxides in the cylinder of a diesel engine running on a gas-diesel process. At the same time, the fuel supply through the gas-diesel process was carried out in the following proportions: natural gas -80%, diesel fuel - 20%. According to the results of the research, a reliable reduction in the content of nitrogen oxides in the cylinder of a diesel engine running on a gas-diesel process was noted.

Combustion of the methane-air mixture can be accompanied by intensive formation and burning of soot, which will lead to an increase in heat losses and heat stress of the chilindro-piston group. The complexity and difficulty of registering the concentration of instantaneous soot particles make it difficult to study the laws of soot formation kinetics in gas diesel. The mechanism of soot formation during combustion of a methane-air mixture in a gas-diesel fuel is even more complex and less studied, since there is charge heterogeneity and other supercritical parameters. The paper proposes a mathematical model of soot formation and burnout in a gas diesel cylinder, which attempts to take into account the features of combustion of atomized fuel and methane-air mixture.

Currently, diesels are widely used as a power plant for the global automotive and tractor fleet. Undoubtedly, this cannot but affect the depletion of the world’s fossil fuel reserves and the rise in prices for oil and petroleum products. On the other hand, due to the constant increase in the number of power plants and the deteriorating environmental situation, it is no less important to maintain the required level of purity of diesel (D) exhaust gases (EG). This raises the question of finding new alternative energy sources and using them in existing engines. An important task in this case is to maintain the power and economic indicators at the level corresponding to the serial engine. The paper presents the results of studies of the working process of D using methanol (M) and rapeseed oil methyl ether (ROME). The minimum ignition portion of rapeseed oil methyl ether is set, which ensures stable operation of the D both at low loads and at idle, and over the entire load characteristic. The required composition of biofuels for the D under study is determined and recommended as optimal. The effective parameters of the D under load conditions when operating on M and ROME are studied in detail. At the same time, experimental characteristics of the effective indicators of a D running on these alternative fuels are established.

In order to improve the environmental performance of diesel engines, the use of renewable energy sources such as biofuels is justified. The factors influencing the processes of fuel combustion and issues allowing to properly provide the necessary conditions for the combustion of biofuels in the combustion chamber of diesel are considered. As a result of experimental studies developed biofuel for diesel engine consisting of methanol and methyl ester of rapeseed oil. Experimental studies of the efficiency and environmental performance of the diesel engine on this biofuel have been carried out.