Deep desulfurization method of refinery C4

Abstract

The invention discloses a deep desulfurization method of refinery C4, which comprises the following steps that at least two fixed bed reactors are adopted; a C4 fraction is subjected to adsorption desulfurization by the action of an adsorbent loaded with a hydrogenated active component; the C4 fraction is switched to another reactor for the adsorption desulfurization after adsorption saturation; hydrogen is supplied to the adsorption saturated fixed bed reactor for a hydrogenated desulfurization reaction; and the adsorbent loaded with the hydrogenated active component is regenerated. Refinery C4 desulfurized by the method can directly serve as a raw production material of MTBE (methyl tert-butyl ether), and isobutylene in the C4 fraction is sufficiently protected and utilized.

Description

technical field [0001] The invention belongs to the desulfurization technology of C4 in a refinery, and in particular relates to a deep desulfurization method of C4 in a refinery. Background technique [0002] The main use of C4 in my country's refineries is to use isobutene to produce methyl tert-butyl ether (MTBE) as a gasoline blending component, and C4 after ether is further used as civil fuel or chemical raw material. [0003] In the process of petroleum refining, refinery C4 produced by coking, atmospheric and vacuum, catalytic cracking and other devices contains a large amount of sulfide, except for H 2 In addition to S, there are various forms of organic sulfur, such as COS, CH 3 SH, C 2 h 5 SH, CH 3 SCH 3 etc., mainly CH 3 sh. The presence of these sulfur will cause poisoning and deactivation of the catalyst in the subsequent processing, which will have a very adverse effect on downstream product processing, environmental protection and equipment corrosion pr...

AI Technical Summary

Problems solved by technology

Although the above-mentioned oxidative extraction and mercaptan removal technology can significantly increase the solubility of mercaptans in alkaline solution and improve the removal rate of mercaptans, this method still has the following disadvantages: (1) Cobalt phthalocyanine catalysts are in the alkali phase and are prone to aggregation and loss. active, resulting in frequent replacement of the catalyst, and the cost of the catalyst is quite high; (2) C4 in the refinery uses lye containing catalyst for mercaptan extraction. Under the condition of catalyst, sodium mercaptide is easy to generate disulfide and bring it into the refined Among the C4 products in the refinery, the desulfurization rate is low, and the total sulfur content of C4 in the refinery exceeds the standard; (3) Due to the use of caustic soda, the pressure on environmental protection has been aggravated. , use ammonia water instead of liquid caustic soda to carry out carbon four pre-alkali washing in refineries, and use gas stripping device to treat ammonia water to regenerate and recycle ammonia, but in this way, gas equipment must be added, and ammonia water is weak in alkalinity and organic sulfur is difficult to elute

It is also possible to wash with solid alkali instead of liquid alkali, and then mix it with active agent into the deodorization tower for deodorization, but it needs to add a special deodorizer, which increases the cost of desulfurization and the desulfurization effect is not ideal

[0005] We know that hydrodesulfurization is an effective and clean method for removing sulfur compounds from petroleum hydrocarbons, but hydrodesulfurization for refinery carbon four is usually difficult to achieve because the hydrogenation activity of carbon four olefins is much higher than that of refinery carbon Hydrodesulfurization activity of organosulfur compounds in four, the hydrodesulfurization process will seriously change the composition of carbon four in the refinery, so that a large amount of isobutene will be saturated, and lose the function of etherification to MTBE

Adopted in CN1900232A is carrier with alumina, cobalt, the hydrogenation desulfurization catalyst of molybdenum bimetallic active component carries out hydrodesulfurization to the liquefied gas of low-sulfur content of refinery carbon four that extracts propylene, butene component, reaction The temperature is 145~300℃, the hydrogen partial pressure is 1.0~2.0MPa, and the liquid hourly volume space velocity is 1.0~5.0. This method adopts the method of extraction to separate olefins, and a large amount of residual olefins will still be hydrogenated and saturated, resulting in olefins In addition, the extraction process is lengthy, and the solvent needs to be regenerated, which increases the processing cost

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