Method for recovering naphthalene from sulfonated tail gas

Abstract

The invention relates to the technical field of 2-naphthol production, discloses a method for recovering naphthalene from sulfonated tail gas, and solves the problems of difficult recovery of sulfonated tail gas, high labor intensity and bad environment. The sulfonated tail gas enters a tail gas condenser, 50-60 DEG C hot water is introduced into a condensing pipe to cool the sulfonated tail gas,and the upper part is sprayed with a sodium sulfite solution to obtain a spraying solution; the spray liquid is led to a phase separation tower for phase separation, and then divided into two phases through density difference, wherein the upper layer is liquid naphthalene, and the lower layer is a sodium sulfite solution. According to the invention, the sodium sulfite solution is used as sprayingwater to neutralize dilute sulfuric acid carried in the tail gas, so that equipment is prevented from being corroded; the 50-60 DEG C hot water is used as cooling water, so that naphthalene solidification can be effectively avoided, and pipeline blockage can be avoided; and by using the phase separation tower, phase separation can be continuously realized, system equipment is simplified, and the recovery quality of refined naphthalene is improved.

Description

Technical field [0001] The invention relates to the technical field of dinaphthol production, in particular to a method for recovering naphthalene from sulfonated tail gas. Background technique [0002] The traditional production of dinaphthol is mainly composed of sulfonation, hydrolysis, naphthalene blowing, neutralization, cooling, filtration, alkali melting, dilution, acidification, boiling, drying, distillation and other units. In the process of sulfonation, refined naphthalene and sulfuric acid The reaction is a reversible reaction. The tail gas contains unreacted naphthalene, water vapor, and a very small amount of sulfuric acid. The crystallization point of naphthalene is 80°C. If the temperature is too low, it is easy to solidify and block the pipeline. Dilute sulfuric acid is very corrosive and is used for naphthalene recovery. Brings great challenges. [0003] The traditional process adopts the sodium naphthalene sulfonate filtrate wastewater cooling spray method to rec...

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Problems solved by technology

[0004] The present invention overcomes the deficiencies in the prior art, provides a high degree of automation and a continuous process for recovering naphthalene from sulfonated tail gas, and solves the problems that the traditional recovery method is not easy to recover sulfonated tail gas, and the labor intensity is high and the environment is bad.

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