A kind of tar dechlorination method

Abstract

The invention discloses a dechlorination method for tar. The method comprises the following steps: heating tar and water to 70-95 DEG C, and fully mixing the two, wherein the adding amount of the water accounts for 5-25% of the mixture of the tar and the water in percentage by mass; at a temperature of 80-95 DEG C, after the tar is fully standing, separating the tar so as to obtain an oil phase and an upper high-chlorine water phase, and then carrying out further centrifugal separation on the obtained oil phase by an ultracentrifuge at a temperature of 50-90 DEG C so as to obtain low-chloride tar and a high-chlorine water phase. According to the invention, through a water washing process, most of chlorine in tar is removed, so that an effect that no alkali is added in tar processing, no corrosion is increased, the metal content of asphalt products such as sodium ions and the like obtained by distillation is low, and useful substances such as phenol and ammonia and the like in the upper high-chlorine water phase obtained after separation also can be recycled is achieved, therefore, the method is economic and environmental-friendly.

Description

technical field [0001] The invention relates to the field of separation and purification, in particular to a tar dechlorination method. Background technique [0002] Atmospheric pressure distillation is used for tar distillation in most coking enterprises in China. The distillation tower is made of ordinary carbon steel or ordinary stainless steel. Some of them use 316L in the corrosion section (180~220°C). 4 Cl, (NH 4 ) 2 SO 4 , NH 4 CNS) will be decomposed into free acid and ammonia, causing corrosion of pipelines and equipment. Especially Cl - It also produces serious intergranular corrosion, stress corrosion, and general corrosion on the 316L material. Cl in tar - The content is about 30~110ppm. In order to reduce corrosion, Na is usually added to the raw tar 2 CO 3 To decompose fixed ammonium salts, neutralize hydrogen chloride, and form stable sodium salts. But this brings Na + All enter into the asphalt, cause the added value of the asphalt products produce...

AI Technical Summary

Problems solved by technology

Its process parameters such as temperature and separation time are not disclosed, and after the second mixing and separation, the water consumption reaches 100%, and the operation is difficult; the second centrifugal separation speed reaches 7000~7500rpm, which requires high equipment and is not easy to achieve in industry ;After vacuum distillation in the distillation tower, the cost of energy consumption is very high

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