What does clean gasoline rely on to increase its octane rating?
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The standards for gasoline are becoming increasingly strict, and the pressure to make it more environmentally friendly is growing. What methods are used by various facilities to raise the standards for gasoline? What approaches are employed to increase its octane rating? What is the typical level of olefins allowed in gasoline these days?
Typically, MTBE is used to improve the octane number of gasoline. High-octane alkylated gasoline is also produced by constructing alkylation units. The sulfur content in gasoline is reduced through selective hydrogenation. The requirements for olefin content under Euro 3 and Euro 4 standards are less than 18%, while in China, the standard for Grade 3 gasoline requires that the combined amount of aromatics and olefins be less than 60%
The control limit for the olefin content in gasoline is not more than 35 (v/v).
Isooctane and n-heptane are added to improve the octane rating.
There are several methods to increase the octane rating of gasoline: First, alter the chemical composition of gasoline by increasing the content of isoparaffins and aromatics. Catalytic cracking, catalytic reforming, isomerization, etc., can be used for processing. II. Add a small amount of octane-boosting additive. III. Add other high-octane components, such as oxygen-containing organic compounds like ethers and alcohols, such as MTBE. Currently, in our country, the olefin content in vehicle gasoline is required to be below 35%, the aromatic content to be no more than 40%, the benzene content to be no more than 2.5%, and the sulfur content to be no more than 500 μg/g. Starting in March 2008, Beijing implemented local standards for vehicle gasoline, requiring that the olefin content in gasoline not exceed 25%, the combined content of olefins and aromatics not exceed 60%, the benzene content not exceed 10%, and the sulfur content not exceed 50μg/g. I’m in the catalysis unit; our main method for reducing olefins is to use the MIP olefin reduction process developed by the Chinese Academy of Sciences.
Additional note: The measures taken in our country to reduce olefins in gasoline include: 1. Optimizing process operating conditions while using olefin-reducing catalysts or additives; 2. Employing olefin-reduction processes such as MIP-CGP (which is the technology we use, as mentioned earlier), MGD technology, and FDFCC technology. 3. Use gasoline desulfurization additives (such as MS-011, etc.). 4. Employ technologies such as the catalytic gasoline hydrogenation isomerization to reduce olefins (RIDOS) developed by the Chinese Academy of Petroleum Sciences.
In the past, MTBE was commonly used to boost the octane rating of gasoline; nowadays, it is mainly achieved by altering the chemical composition of gasoline by increasing the content of isoparaffins and aromatics. Catalytic cracking, catalytic reforming, isomerization, and alkylation units can be used to produce high-octane gasoline. In China, clean gasoline is required to have an olefin content of less than 35% (v/v).
MTBE is no longer allowed to be used; for specific requirements, refer to the Euro III and Euro IV standards as a guide.