Crude oil is a mixture of various kinds of oil and residual oil (asphalt). After distillation and purification in the refinery, the temperature required for the distillation equipment to produce products is from low to high, followed by tower top gas (similar to natural gas), gasoline, kerosene, diesel oil, residual oil (asphalt), and the product density increases in turn.
In practice, most refineries mix kerosene products with half gasoline and half diesel, but do not produce kerosene products.
汽油燃点低，可由活塞点燃，汽油机体积小，重量轻，所以动力小的汽车如汽车、摩托车、三轮车都是用汽油机。汽油标签常用有92 #、95 #、98 #等，它指的是相对燃烧稳定性，标签越大，爆炸性越好。
Gasoline has a low ignition point and can be ignited by a piston. Gasoline engines are small in size and light in weight. Therefore, automobiles with small power such as automobiles, motorcycles and tricycles all use gasoline engines. There are 92, 95 and 98 gasoline labels, which refer to the relative combustion stability. The larger the label, the better the explosiveness.
柴油燃点高，需要用压缩高温空气点火。然而，高温高压决定了柴油发动机相对较重，但柴油发动机可以提供大量的动力。因此，柴油机主要用于船舶、起重机、拖拉机、卡车和坦克等大功率机械。柴油的一般编号为0 #，-10 #，表示柴油的凝固点温度。
Diesel fuel has a high ignition point, so it needs to be ignited with compressed high temperature air. However, the diesel engine is relatively heavy because of high temperature and high pressure, but it can provide a lot of power. Therefore, diesel engine is mainly used in ships, cranes, tractors, trucks, tanks and other high-power machinery. The general number of diesel oil is 0 ? - 10 ?, indicating the freezing point temperature of diesel oil.
Kerosene has a burning point between the first two, which can be ignited by an electric piston, and the combustion is stable. In the early days of liberation, kerosene was used in most rural areas. On the other hand, aviation kerosene needs special purification and mixing. Its combustion stability is very high. It burns in the engine of the aircraft, and then ejects rapidly, providing enough power for the aircraft.
1. Gasoline is volatile, while diesel is not. Therefore, gasoline vehicles have fuel evaporation emissions, which are composed of hydrocarbons (HC).
2. Gasoline is easy to mix with air, and it is not easy to separate after mixing. Gasoline and air can be mixed very evenly, almost no local too thick or too thin and liquid oil drops. Gasoline molecules are smaller. The mixture of diesel and air is uneven. Under high temperature and hypoxia, oil is easy to form soot. When diesel oil burns, it will produce some unpleasant organic gases. As a result, diesel emissions have a peculiar smell.
3. Chemical difference: gasoline has fewer carbon atoms (8-10), while diesel has 12-15, so diesel has more energy. Diesel does not need to be ignited, it will automatically ignite at higher pressure, so it is more efficient (in fact, the maximum utilization rate is only 30%), but it is bulky and noisy. Gasoline needs to be ignited, so the gasoline engine is small in size and low in noise (efficiency is only 15%).