Processing method of middle and low temperature coal tar

Abstract

The invention relates to a processing method of middle and low temperature coal tar. The processing method comprises the following steps: completing countercurrent contact wash and separation at least twice on narrow fraction phenol oil PO and alkali liquid SHW which are obtained by fractionating raw coal tar to obtain a water solution of oil-containing sodium phenolate and dephenolized phenol oil; washing the dephenolized phenol oil with washing water to obtain washed dephenolized phenol oil DPO and oil washing water, wherein at least part of the oil washing water is circulated to be used as the washing water, and the residual oil washing water enters an alkali washing process for the phenol oil; and further, fractionating the washed dephenolized phenol oil to obtain tower bottom residual liquid DLO the yield of which is lower than 5% and refined dephenolized phenol oil, wherein the washed dephenolized phenol oil DPO or the refined dephenolized phenol oil TDPO enters a hydro-upgrading process of the raw coal tar distillate oil, and the tower bottom residual liquid DLO enters a coking unit of raw coal tar residual oil to complete the coking process and recycle the coke products. The processing method provided by the invention has the advantages of reducing the consumption of the alkali liquid, reducing the quantity of alkali metal ions in the dephenolized phenol oil, and the like, integrates the coal tar hydro-upgrading process and the coal residual oil coking process into a combined technique, and is especially suitable for the comprehensive utilization of the middle and low temperature coal tar.

Description

technical field [0001] The invention relates to a method for processing medium and low temperature coal tar, which comprises fractionating medium and low temperature coal tar to obtain narrow-fraction phenol oil, and processing the narrow-fraction phenol oil to obtain crude phenol and dephenolized oil suitable for use as raw material oil in the hydrogenation upgrading process; especially In other words, the present invention relates to a comprehensive processing method of medium and low temperature coal tar, which combines the phenol extraction process, coal tar distillate oil hydrogenation upgrading process and coal tar residue coking process to form a combined process to realize the production of medium and low temperature coal tar full fractions. deep processing. Background technique [0002] As we all know, phenols are one of the main chemical products in coal tar. The composition and yield of phenols in coal tar are related to the composition of coal blending, the prope...

AI Technical Summary

Problems solved by technology

[0010] The disadvantage of the process of extracting phenol from medium and low temperature coal tar is: the process produces phenol-containing wastewater

[0016] ③Phenol oil alkali washing process usually adopts two-stage countercurrent washing, and the recovery rate of phenol is low;

[0017] ④ There is no water washing process for dephenolized oil, and the amount of alkali metal ions carried in the dephenolized oil is large;

[0018] ⑤The distillation and refining process of dephenolized oil after water washing is not set up, and the deep dehydration and deep dealkalization of metal ions cannot be realized to prepare the raw material oil for the hydrogenation upgrading process;

[0019] ⑥Phenol residue obtained from the refining process of neutral oil or crude phenol cannot be used as raw material oil in the hydrogenation upgrading process

[0020] The process of extracting phenols from medium and low temperature coal tar and taking into account the process of dehydrogenation and upgrading of dephenolized oil has not been reported.

Images