In connection with the depletion of oil reserves and increasing complexity of its production, much attention is paid to the use of alternative fuels for road transport non-petroleum origin. They can completely replace the fuel derived from petroleum, or serve as additives, reducing fuel consumption. Of greatest interest are the fuel in use that do not require significant changes to the existing engine design. Developed technology for producing fuels such as oil derived from using coal, oil shale, etc. However, the cost of such fuels is still quite high. More promising is the use as fuel alcohols (methanol, ethanol) or their mixtures with gasoline. Alcohols have a greater than gasoline octane, but lower heating value, high specific heat of vaporization and a low boiling point.
When using mixture of gasoline, 15% methanol and 7% of isobutyl alcohol consumption of gasoline was reduced by 14%, and with separate supply of methanol and gasoline – by 20%. Work is underway to use hydrogen as fuel. Significant progress has been made in using mixtures benzinovodorodnyh to significantly reduce fuel consumption. Greatest practical importance is the use of hydrocarbon gases. These gases can be applied in liquid form under pressure 1.6 … 2.0 MPa (butane, propane and mixtures thereof) or in the form in which they are mined – methane, ethane, etc. The use of hydrocarbon gases, except for saving fuel oil origin, also leads to lower consumption of lubricants and reduce engine wear.
However, lower heat of combustion of natural gas for the same causes with a petrol engine compression reduction in engine power by 15 … 20%, and the time at 20 … 25%. As a result, the transport light weight cylinders containing gas is reduced by 10 … 15% capacity and more than 2 times – cruising range due to the limited availability of fuel (inexpedient to carry extra cylinders). However, by increasing the degree of compression of cylinders of polymeric or composite materials, these shortcomings can be largely eliminated.