Method for separating and recycling naphthalene residual oil

Abstract

The invention discloses a method for separating and recycling naphthalene residual oil. The method sequentially includes steps of feeding a raw material which is the naphthalene residual oil; removinglight components, to be more specific, separating the light components in the naphthalene residual oil and delivering tower bottom discharged materials to naphthalene removal towers; removing naphthalene, to be more specific, condensing tower top gas phase by the aid of condensers, then delivering a part to tower tops to be used as reflux, delivering another part to naphthalene refining sectionsand delivering tower bottom discharged materials to benzothiophene towers; removing benzothiophene, to be more specific, condensing tower top gas phase by the aid of condensers, then feeding condensedfluid into condensed fluid tanks, delivering a part to tower tops to be used as reflux, delivering another part into static crystallizers, delivering tower bottom discharged materials to byproduct storage tanks and returning mother liquor to light component removal towers by means of circulation. The method has the advantages that benzothiophene products in the naphthalene residual oil are extracted, accordingly, the naphthalene content can be increased, refined naphthalene can be processed in crystallizers, and resources can be optimally effectively utilized; naphthalene residual oil recycling is coupled with naphthalene refining devices, accordingly, naphthalene consumption can be reduced and can reach 1.04 tons industrial naphthalene / ton refined naphthalene, and the benzothiophene yield can reach 70% at least.

Description

technical field [0001] The invention discloses a method for separating and recovering naphthalene residual oil, which belongs to the technical field of coal tar washing oil processing. Background technique [0002] Under normal circumstances, the raw material industrial naphthalene with a naphthalene content of about 95.9% is further crystallized by a crystallizer to increase the naphthalene content to 99.3%, and the remaining naphthalene residue (containing about 50% naphthalene and 30% benzothiophene) is mixed into the carbon black oil Production of carbon black, although this utilization method solves the outlet problem of the by-product naphthalene residual oil, it also brings disadvantages: 1) The benzothiophene in the naphthalene residual oil contains 23.8% sulfur, and the sulfur concentration in the carbon black tail gas increases, which is easy to It pollutes the environment and increases the cost of tail gas desulfurization; 2) 50% of naphthalene and 30% of benzothi...

AI Technical Summary

Problems solved by technology

[0002] Under normal circumstances, the raw material industrial naphthalene with a naphthalene content of about 95.9% is further crystallized by a crystallizer to increase the naphthalene content to 99.3%, and the remaining naphthalene residue (containing about 50% naphthalene and 30% benzothiophene) is mixed into the carbon black oil Production of carbon black, although this utilization method solves the outlet problem of the by-product naphthalene residual oil, it also brings disadvantages: 1) The benzothiophene in the naphthalene residual oil contains 23.8% sulfur, and the sulfur concentration in the carbon black tail gas increases, which is easy to It pollutes the environment and increases the cost of tail gas desulfurization; 2) 50% of naphthalene and 30% of benzothiophene in naphthalene residual oil are burned in vain, resulting in a great waste of resources

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