There are two ways to increase the octane number of gasoline: simple - by adding antiknock agents (special additives) to it, and difficult - to apply a special technology that will increase the cost of the product. It is possible to "make" AI-92 from AI-76 gasoline, and AI-95 from AI-92. However, this also has its negative side. Poor-quality fuel at obscure gas stations, where the octane number is artificially increased, leads to serious and costly car breakdowns.
It is necessary
- - methyl tertiary butyl ether;
- - ethyl and methyl alcohol;
- - tetraethyl lead.
Instructions
Step 1
Add MTBE (methyl tertiary butyl ether) to gasoline, which is a flammable colorless liquid with a specific odor. It is one of the most commonly used octane boosters today. MTBE has a high octane number and is non-toxic. When adding 10-15 percent to the composition of gasoline, the increase will be approximately 6-12 units. Most high-octane gasolines are manufactured using this or a similar ester grade additive. The disadvantage of MTBE is its high volatility, since in hot weather it can evaporate from gasoline.
Step 2
Add alcohol (ethyl and methyl) to the gasoline. For example, a 10% addition of ethyl alcohol to Ai-92 raises the octane number to almost 95 units. In addition, the toxicity of the exhaust gases is reduced. But the use of alcohols leads to an increase in the pressure of saturated vapors. This can contribute to the formation of vapor lock in the fuel line. In addition, a significant problem is the good water solubility and hygroscopicity of ethyl alcohol. This requires special storage conditions for the mixture and periodic monitoring of the content of the alcohol component. If not observed, water may appear in gasoline, and this leads to increased fuel consumption, poor combustion, and with a large percentage of it, ice jams may appear in winter.
Step 3
Add tetraethyl lead Pb (C2H5) 4. TPP is considered one of the best antiknock agents. It is an oily, colorless liquid with a boiling point of about 200 ° C. They began to use TPP as an antiknock agent in 1921, and today it is one of the most effective and inexpensive means of concentration 0.05%. It makes it possible to increase the octane number of gasoline up to 15-17 points. Tetraethyl lead is not added in its pure form, because during combustion it forms carbon deposits - lead oxide, which is deposited on pistons, valves and other parts. To remove it from the combustion chamber, ethyl bromide, dibromopropane, dibromoethane should be used. During combustion, they form volatile compounds with lead, which are easily removed from the combustion chamber. A mixture of TPP with these components and a special dye is called ethyl liquid, gasoline with such components is called leaded. Today, the manufacture of leaded gasoline is prohibited, as it has a high degree of toxicity. Lead, accumulating in the body, causes multiple sclerosis, as it is a poison. Leaded gasoline must not be used in vehicles equipped with an exhaust gas catalytic converter. They are disabled when the engine is running after a few hours. Isooctane, neohexane, isopentane, benzene, toluene, acetone are also antiknock agents.
