Method for reducing sulfur content of catalytically cracked gasoline

Abstract

The present invention provides a method of reducing sulfur content in fcc gasoline, the fraction below 250 DEG C from the main fractionator top of the catalytic cracking unit is stepped cooled to obtain a light gasoline fraction, a middle gasoline fraction and a heavy gasoline fraction, the light gasoline fraction enters in an alkali washing sweetening unit by a absorption and stabilization system of the catalytic cracking unit; the middle gasoline fraction processes selective hydrodesulfurization in a first hydrogenation region, the obtained hydrogenation middle gasoline fraction enters in the alkali washing sweetening unit to process deodorization; the heavy gasoline fraction processes hydrodesulfurization and octane number recovery reaction in a second hydrogenation region, the hydrodesulfurization heavy gasoline fraction is mixed with the light gasoline fraction after deodorized and the hydrodesulfurization middle gasoline fraction, a clean gasoline product is obtained. The method of the invention greatly reduces the sulfur content and the alkene content in fcc gasoline, the sulfur content of the product meets the need of sulfur in Europe IV discharging standard, the device has less investment, lower energy consumption because of the simple process of fcc gasoline hydrogenation.

Description

technical field [0001] The invention belongs to a method for refining hydrocarbon oil in the presence of hydrogen, more specifically, a method for reducing the sulfur content of catalytic cracking gasoline and producing clean gasoline products with low sulfur and olefins. Background technique [0002] With the rapid development of the automobile industry, the pollution of automobile exhaust to the environment is becoming more and more serious. In order to protect the environment, countries around the world have put forward stricter restrictions on the composition of motor gasoline to reduce the emission of harmful substances in automobile exhaust. The content of sulfur and olefins in gasoline can effectively reduce the emission of harmful substances in automobile exhaust. The United States requires that the sulfur content in gasoline be reduced to below 30 μg / g in 2006, and the olefin content is less than 14% by volume. In 2005, Europe began to implement gasoline specificat...

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Problems solved by technology

In this method, heavy naphtha is subjected to secondary hydrogenation, which increases the energy consumption of the device, and at the same time reduces the olefin content to a limited extent

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