Continuous refining separation device and method for coal gasification crude phenol

Abstract

The invention discloses a continuous rectification separation device and a continuous rectification separation method for coal gasification crude phenol. The device comprises a first-level pretreatment acidifying unit consisting of a film scraping evaporator, a primary acid regulating tank group and a buffer tank, a second-level pretreatment oxidizing unit consisting of a static mixer and a secondary acid regulating tank and a rectifying tower system consisting of a deslagging tower, a dehydrating tower, a phenol refining tower, an o-cresol refining tower and a m, p-cresol refining tower, wherein the first-level pretreatment acidifying unit is connected with the phenol deslagging tower; and the phenol deslagging tower is connected with the second-level pretreatment oxidizing unit and is connected with each rectifying tower system respectively. By the device and the method, the raw material of the coal gasification crude phenol is subjected to decoloration, deodorization, desulfuration, impurity removal and the like effectively, so that products of high-purity phenol with the purity of more than 99.5 weight percent, high-purity o-cresol with the purity of more than 96.0 weight percent, high-purity m, p-cresol with the purity of more than 99.0 weight percent, mixed xylenol and phenol residual oil can be obtained. The method has the characteristics of reasonable process, high automaticity, low process energy consumption, high quality of products, high stability and the like, and is an efficient and feasible continuous rectification separation process for the coal gasification crude phenol.

Description

technical field [0001] The invention relates to a refining method of coal gasification crude phenol, in particular to a device and method for continuous rectification and separation of coal gasification crude phenol. Background technique [0002] Coal gasification phenols are one of the main chemical products extracted from coal gas washing water and coal tar. The yield and composition of coal gasification crude phenols are related to the properties of coal gasification raw material coal and its gasification operating conditions. In the coal chemical industry, the source of coal gasification crude phenol comes from the phenolic compounds extracted from the phenol-containing wastewater produced during the coal gasification process, and the phenol oil fraction produced by the fractionation of coal tar on the other hand, two sources The crude phenolic components of crude oil basically contain impurities such as phenol, o-cresol, m-p-cresol, xylenol, higher phenols, water, and n...

AI Technical Summary

Problems solved by technology

At present, most of the refining treatment methods for phenolic compounds involve the refining process of chemically synthesized phenols, and few involve the continuous treatment of coal gasification crude phenols. In the domestic literature, there is only a continuous refining and separation device for coking crude phenols patented by China. and method (CN200910228047.2) discloses a separation device and method for continuous rectification of coked crude phenol, although a series of pretreatment methods have been adopted for the continuous process, but in the whole process due to a large amount of high-grade Phenol has been polluted by sulfuric acid, so it can no longer be used for subsequent treatment, resulting in a large waste of resources, and in the process of pretreatment and acid adjustment, due to the instability of crude phenol raw materials and the hysteresis of detection feedback, the crude phenol after acid adjustment The fluctuation of raw material pH is unstable, and it is impossible to ensure that the pH is always in the optimal range, which will affect the deslagging effect of the subsequent process and the continuous stability of the whole process. Obviously, this method is not suitable for coal gasification where high-grade phenols can be effectively used. Continuous stabilization of crude phenol

[0005] In foreign literature, there is also Japanese patent JP62-12731, which uses hydrogen peroxide and white clay to refine the method to pretreat crude phenol, which can convert the mercaptan and other compounds of the raw material into disulfides with less odor and then refine them by white clay. Crude phenol, experiments show that this kind of pretreatment has good deodorization and desulfurization effects, but its decolorization effect is very poor, and the product quality after refining crude phenol is quite unstable, which seriously affects the refining effect and quality of coal gasification crude phenol Recovery value

[0006] Although the total amount of crude phenol raw materials accounts for a small proportion in the total coal chemical products, the modern coal chemical industry, especially China's coal chemical industry, is very large, and the corresponding total amount of crude phenol raw materials for a coal chemical project is also It has reached tens of thousands of tons or more. Therefore, the intermittent vacuum distillation process with simple equipment and less investment used by domestic and foreign companies in the past is to use two-tower or three-tower batch distillation tower devices and processes to complete slag removal, Several processes such as dehydration, phenol refining, cresol refining and xylenol refining are far from being able to meet the needs of such a huge processing capacity.

As we all know, due to the process characteristics of batch rectification and the heat-sensitive characteristics of phenolic compounds, there must be phenomena such as decomposition, polymerization, coking, and carbonization of phenolic compounds in the separation process of batch rectification, which will affect the quality and yield of products, so that The stability of the product quality of the whole process is relatively poor. At the same time, in the process of batch rectification, there are too many transitional fractions between the various components, which requires repeated rectification, which also results in a large energy consumption in the whole separation process. Obviously, from the perspective of process reliability and In terms of economy, the process of continuous distillation, purification and separation of crude phenol is more suitable for large-scale treatment of crude phenol in coal gasification

Images