Studies on FCC Gasoline to Light Olefins and High Octane Number Gasoline with Low Olefin Content

摘要

Light olefins are major basic chemical materials. With the development of global economy the demand for ethylene and propylene is increasing greatly. Presently, 90% ethylene and 70% propylene in the world are produced by thermal cracking of hydrocarbons. However, this process has many disadvantages such as high reaction temperature, large energy consumption, expensive and specially made units, low yield of propylene, etc. In order to improve the production of light olefins, many studies have been carried out worldwide, in which the catalytic pyrolysis with heavy oil as the feed is a very important aspect. The olefin content in FCC gasoline which contributes about 80% commercial gasoline in China can not meet the new gasoline specifications. The current methods of reducing olefin content may lead to a significant loss of octane number, for the octane number of olefins is higher. If we crack olefins in FCC gasoline selectively to light olefins by using specially made catalysts at appropriate conditions, then on one hand light olefins can be produced and on the other hand the octane number of gasoline may be retained or enhanced as aromatics content increases.