Method for producing low-sulfur gasoline from catalytically cracked gasoline

Abstract

The invention discloses a method for producing low-sulfur oil with catalytic cracking gasoline. The method comprises the following steps: full cut catalytic cracking gasoline is subjected to fixed-bed oxidative deodorization to convert a majority of mercaptan into disulphides and then distillated to give light boiling range naphtha, mediate boiling range naphtha and heavy boiling range naphtha; the mediate boiling range naphtha serves as a reforming prehydrogenation material and can improve the octane number and reduce content of sulfur; the heavy boiling range naphtha is subjected to selective hydrodesulphurization treatment to give a low-sulfur product which is mixed with the light boiling range naphtha to give a clean gasoline product. Compared with the prior art, the method reduces the content of sulfur in distillation cut of inferior naphtha to below 10mu g / g, achieves small loss of octane number, qualified mercaptan content and gives high quality clean gasoline products. The method can deal with materials of different properties, has wide adaptability, flexibility, mature process technology and high reliability.

Description

technical field [0001] The invention relates to a method for deep desulfurization of catalytic cracking gasoline to produce clean gasoline, in particular, the invention relates to a process for producing clean gasoline with sulfur content less than 10 μg / g by catalytic cracking gasoline. Background technique [0002] Reducing the sulfur content of gasoline can greatly reduce the emission of harmful substances in automobile exhaust. Therefore, the new standards of clean gasoline in various countries in the world have put forward stricter and stricter restrictions on sulfur content. The European Class IV vehicle exhaust emission standard (EU2005 standard) stipulates that after 2005, the sulfur content of gasoline is ≯50μg / g, and the olefin content is ≯18v%. Europe plans to implement "sulfur-free gasoline (ULSG)" with a sulfur content of less than 10μg / g in 2009 new standard. The US U.S.EPA Tier 2-II standard stipulates that the sulfur content of American clean gasoline after ...

AI Technical Summary

Problems solved by technology

The disadvantage of this patented method is that because the heavy fraction HDS product contains H 2 The larger molecular mercaptans generated by the secondary rearrangement of S and olefins, on the one hand, reduce the depth of HDS, on the other hand, subsequent dethiol treatment must be carried out

The desulfurization rate of this patented method is usually 80.0%-90.0%, the sulfur content of the product is generally 50μg / g-200μg / g, and the octane number (RON) loss of the research method is ≯2.0 units, which cannot meet the sulfur content of clean gasoline produced by refineries. ≯10μg / g technical requirement

[0010] In the existing technology, the main problem of FCC gasoline production of low-sulfur clean gasoline products is that several contradictions cannot be solved at the same time, such as the contradiction between desulfurization depth and octane number loss, sulfide removal and sulfur removal under hydrodesulfurization conditions. The contradiction between alcohol generation, deodorization and desulfurization, etc., make it impossible to obtain clean gasoline products with low sulfur, less octane loss and qualified mercaptan at the same time with existing technology

In addition, the prior art method has poor flexibility and poor adaptability to different raw materials

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