A secondary utilization device and utilization process of coking crude benzene separation water

Abstract

The invention relates to a device and process for secondarily utilizing coked crude benzene separation water. Separation water distilled by a debenzolization tower for a crude benzene coking procedure serves as a raw material, crude benzene separation water separated by a light benzene control separator is introduced into a final cooling tower as updating supplementation water through a pipeline, and a trace amount of a NaOH solution with the concentration of 40 percent for ammonia still is supplemented into the final cooling tower, so that the separation water and the NaOH solution are mixed to form an alkaline solution; after final cooling circulation, the redundant solution is directly fed into a surplus ammonia water tank from an outlet of a circulating pump and enters an ammonia still system. The separation water serves as the supplemented water, so that a great amount of industrial new water is saved, acid mist carried in coal gas can be absorbed and neutralized by supplementing the trace amount of the NaOH solution, packing supporting of the final cooling tower is prevented, and corrosion prevention of equipment is realized; moreover, part of benzene in the separation water in contact with the coal gas is volatilized, directly enters the coal gas, and reaches a benzene washing tower, and part of light benzene in the separation water is recycled. The process is simple in operation, environmentally-friendly, energy-saving, low in investment cost, and safe and reliable to operate.

Description

technical field [0001] The invention relates to a device and a process for secondary utilization of coking crude benzene separation water, in particular to a device and process for secondary utilization of the separated water after the distillation of a debenzene tower passes through a control separator, and belongs to the technical field of coke oven gas purification . Background technique [0002] At present, in the process of producing crude benzene or light benzene, coking plants generally adopt the steam debenzene method. When using this method, a certain amount of separated water is often produced, and this part of the separated water of crude benzene is about 0.8-1.2 times the output of light benzene. Coking plants basically use gas pipelines that are collected and concentrated to send and suck gas, and then mixed into the ammonia water system for treatment. , basically cannot be effectively utilized, and a certain amount of volatile benzene contained in the separate...

AI Technical Summary

Problems solved by technology

The process uses crude benzene separation water to dilute the final cooling circulating liquid in the final cooling tower, which reduces the concentration of acid in the final cooling circulating liquid to a certain extent, and reduces the corrosion of the final cooling system due to the acid content of the final cooling circulating liquid; The solution is used as the acid distribution of the ammonium sulfate plant and the flushing water of the spray saturator, which effectively reduces the consumption of new industrial water in the final cooling tower. However, because the crude benzene separation water contains a high concentration of benzene, this part of the separation water Sent into the saturator as supplementary water, in the full flow tank of the saturator, because the temperature is about 55°C, a large amount of light benzene will be volatilized, polluting the environment and affecting the health of the workers. Benzene, the centrifuge separation process also produces a large amount of benzene gas, which seriously endangers the personal safety of centrifuge operators

[0003] Chinese patent "a coking indirect final cooling tower circulation washing process", patent number: CN200910067457, the invention relates to a coking indirect final cooling tower circulation washing process, the process is to use crude benzene to separate water and mix tar, and then use The naphthalene washing treatment of the final cooling tower combines the indirect final cooling technology, crude benzene separation water and tar mixed washing technology, but the process has great defects. First: because the process is blended with tar, the original The gas degreased by the electric tar collector will be tarred again, which will cause serious blockage to the subsequent gas pipeline and the user's nozzle, which is not advisable

Second: After the tar is added, the gas will contain a large amount of tar. In the benzene washing tower, the washing oil is used to wash the gas, and a large part of the tar will be dissolved in the washing oil, and the washing oil will be sent to the tube furnace for benzene removal. Towers and heat exchangers, etc., will cause serious blockage of equipment and affect the efficiency of benzene removal

The process uses crude benzene separation water to dilute the final cooling circulating liquid in the final cooling tower, which reduces the concentration of acid in the final cooling circulating liquid to a certain extent, and reduces the corrosion of the final cooling system due to the acid content of the final cooling circulating liquid; The solution is used as the acid distribution of the ammonium sulfate plant and the flushing water of the spray saturator, which effectively reduces the consumption of new industrial water in the final cooling tower. However, because the crude benzene separation water contains a high concentration of benzene, this part of the separation water Sent into the saturator as supplementary water, in the full flow tank of the saturator, because the temperature is about 55°C, a large amount of light benzene will be volatilized, polluting the environment and affecting the health of the workers. Benzene, the centrifuge separation process also produces a large amount of benzene gas, which seriously endangers the personal safety of centrifuge operators

[0005] It can be seen that the existing technical solutions have not completely and effectively solved the above-mentioned technical problems that have plagued the industry for a long time.

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