CN111732971A

CN111732971A - Treatment method of tar residues

Info

Publication number: CN111732971A
Application number: CN202010504317.4A
Authority: CN
Inventors: 田振军
Original assignee: Shaanxi Zhenhou Energy Technology Co ltd
Current assignee: Shaanxi Zhenhou Energy Technology Co ltd
Priority date: 2020-06-05
Filing date: 2020-06-05
Publication date: 2020-10-02

Abstract

The invention belongs to the field of chemical industry, and discloses a tar residue treatment method, which comprises the following steps: step 1, heating tar residues by a preheater to obtain heated tar residues; step 2, adding water into the heated tar residues through a dilution tank for dilution to obtain diluted tar residues; step 3, centrifuging the diluted tar residue by using a centrifuge to obtain liquid and solid; step 4, sending the liquid into a clarifying tank for clarification to obtain water and tar; step 5, feeding the solid into a carbonization pyrolysis furnace for pyrolysis to obtain tar and coke particles; cooling the tar by a condenser to obtain cooled tar; the tar residue treatment method is simple, easy to operate and implement and low in cost, and the recovery rate of tar components in the tar residue reaches 90%, so that the purposes of recycling, reducing and harmlessly treating the tar residue are really achieved; meanwhile, the coke particles separated from the tar residues are sent into a powder storage to be treated as fuel, so that the resource utilization rate is further improved.

Description

Treatment method of tar residues

Technical Field

The invention relates to the field of chemical industry, in particular to a tar residue treatment method.

Background

The tar residue is mainly derived from deposits in the coal tar tank produced by the coke-oven plant. In the coking production process, after raw coke oven gas escaping from a coke oven is cooled in a gas collecting pipe and a primary cooler, high-boiling-point organic compounds are condensed to form coal tar; meanwhile, coal dust, semicoke, graphite and ash content carried in the coal gas are mixed in the coal tar to form lumps with different sizes, and the lumps are the tar residues. The fixed carbon content in the tar residue is about 60 percent, the volatile content is about 33 percent, and the ash content is about 4 percent; the porosity of the tar residue is about 63%, and the true density is 1.27-1.30 t/m; the main components of the coal tar oil comprise coal powder, coke powder, heavy tar and the like.

The tar residues are dangerous solid wastes, contain various harmful substances such as benzene and the like, and if the tar residues are directly discharged, the tar residues not only pollute the atmospheric environment, but also pollute underground water sources after permeating into the ground, and harm the physical and mental health of people. The conventional treatment method at present comprises the following steps: firstly, directly adding tar residues into coking coal or preparing molded coal for coking; transporting the uncompensated or extremely low price to rural areas in suburbs to be used as the soil kiln fuel; and thirdly, re-purifying the tar residue. The second method is, among others, prohibited by national regulations. The third method is too high in production cost, and the temperature is 600 ℃ and 900 ℃. The first method, tar residue blending coal coking, is to mix and extrude the pulverized blended coal in the coal preparation working area as the raw material and the tar residue produced in the gas purification working area as the binder to produce the molded coal, and finally blend the molded coal in proportion into the coking coal for coking, and the method has the following problems:

a) because the tar residues contain part of tar, the caking property is high, the tar residues are attached to a belt to cause serious belt pollution, sometimes cause the belt to fluctuate, and increase the coal falling amount. b) The tar residue collected by the tar residue hopper is not uniform, generally, the bottom is the tar residue, and the middle upper part is ammonia water, so that the preparation of the molded coal is not uniform. c) Because the tar residue contains ammonia water, the heat consumption of the coke oven is increased after the briquette is prepared. d) The tar residues generated by digging the storage tank are concentrated, the briquette has insufficient treatment capacity and needs to be stored for a period of time, and a large amount of tar residues flow along with rainwater in rainy days, thereby seriously polluting the environment. e) The tar residues are sticky substances, are easy to freeze into blocks in winter, and need to be melted by adding steam in the using process. In the heating process, various toxic substances such as ammonia, benzene, phenols, naphthalene and the like are easy to volatilize and escape, the environment is polluted, and the corrosion to molded coal equipment and environment-friendly equipment is serious.

Disclosure of Invention

Aiming at the problems in the prior art, the invention aims to provide a tar residue treatment method which is simple, easy to operate and implement and low in cost, and can achieve the purposes of recycling, reducing and harmlessly treating tar residues, wherein the recovery rate of tar components in the tar residues reaches 90%; meanwhile, the coke particles separated from the tar residues are sent into a powder storage to be treated as fuel, so that the resource utilization rate is further improved.

In order to achieve the purpose, the invention is realized by adopting the following technical scheme.

A tar residue treatment method comprises the following steps:

step 1, heating tar residues by a preheater to obtain heated tar residues;

step 2, adding water into the heated tar residues through a dilution tank for dilution to obtain diluted tar residues;

step 3, centrifuging the diluted tar residue by using a centrifuge to obtain liquid and solid;

step 4, sending the liquid into a clarifying tank for clarification to obtain water and tar;

step 5, feeding the solid into a carbonization pyrolysis furnace for pyrolysis to obtain tar and coke particles; and cooling the tar by a condenser to obtain the cooled tar.

Preferably, in step 1, the heating is to 50-70 ℃.

Preferably, in step 4, the water separated from the clarifying tank is sent to the diluting tank for recycling.

Preferably, in step 5, the temperature of the pyrolysis is 350-450 ℃.

Preferably, in step 5, the cooling is to 45-55 ℃.

Preferably, the method also comprises a step 6 of mixing the tar in the step 4 with the tar cooled in the step 5, and naturally settling to remove water to obtain crude tar; and distilling the crude tar by using a rectifying tower to separate light oil, heavy oil, residual oil and water.

Compared with the prior art, the invention has the beneficial effects that:

the tar residue treatment method is simple and easy to operate and implement, the tar residue is treated in a mode of combining centrifugal separation and high-temperature thermal cracking, the recovery rate of tar components in the tar residue can reach 90%, and the purposes of recycling, reducing and harmlessly treating the tar residue are really achieved. In addition, the coke particles separated from the tar residues are sent to a powder storage to be treated as fuel, so that the resource utilization rate is further improved.

Drawings

The invention is described in further detail below with reference to the figures and specific embodiments.

FIG. 1 is a flow chart of the tar residue treatment method of the present invention.

Detailed Description

Embodiments of the present invention will be described in detail below with reference to examples, but it will be understood by those skilled in the art that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.

A tar residue treatment method comprises the following steps:

step 1, heating tar residues to 60 ℃ by using a preheater to obtain heated tar residues.

And 2, adding water into the heated tar residues through a dilution tank for dilution to obtain diluted tar residues, so as to facilitate subsequent centrifugal operation.

And 3, performing solid-liquid separation on the diluted tar residues by using a high-efficiency centrifugal machine to obtain liquid (containing water and tar) and solid.

Step 4, sending the liquid into a clarifying tank for oil-water separation to obtain water and tar; wherein, the water separated from the clarifying tank can be sent into the diluting tank to be used as the diluting water fed by the centrifugal machine for recycling; the tar is sent to a water-containing coal tar storage tank for subsequent treatment.

And 5, feeding the solid separated by the centrifuge into a carbonization pyrolysis furnace for pyrolysis, wherein the carbonization pyrolysis furnace adopts a continuous feeding mode, the temperature is set at 400 ℃, hot flue gas generated by burning diesel oil and unique heat-conducting mesons in the carbonization pyrolysis furnace are used for dispersing and heating, the materials are prevented from coking and adhesion, and tar gas phase and coke particle solid phase are generated after the solid is pyrolyzed. Wherein, the tar gas phase is extracted as oil component, is cooled to 50 ℃ after being condensed by a first-stage condenser and a second-stage condenser, and is sent to a tar storage tank for subsequent treatment; the solid phase of the coke particles is sent to a powder storehouse to be treated as fuel, and can be sold outside. Most of the flue gas is recycled, the heat is recovered, and the discharged part of the flue gas is sent to a desulfurization and denitrification treatment system to be discharged after reaching the standard.

And 6, mixing the tar separated by the centrifuge in the step 4 with the tar extracted by the carbonization pyrolysis furnace in the step 5, naturally settling and layering to remove water, continuously separating the obtained crude tar by adopting a three-layer rectifying tower, and separating light oil, heavy oil, residual oil and water.

Although the present invention has been described in detail in this specification with reference to specific embodiments and illustrative embodiments, it will be apparent to those skilled in the art that modifications and improvements can be made thereto based on the present invention. Accordingly, such modifications and improvements are intended to be within the scope of the invention as claimed.

Claims

1. The tar residue treatment method is characterized by comprising the following steps:

step 1, heating tar residues by a preheater to obtain heated tar residues;

step 3, centrifuging the diluted tar residue by using a centrifugal machine to obtain liquid and solid;

2. The tar slag treatment method according to claim 1, wherein the heating is performed to 50 to 70 ℃ in step 1.

3. The tar slag treatment method according to claim 1, wherein in step 4, the water separated from the clarifier is sent to a dilution tank for recycling.

4. The tar slag treatment method as claimed in claim 1, wherein the pyrolysis temperature in step 5 is 350-450 ℃.

5. The tar slag treatment method according to claim 1, wherein the cooling is to 45 to 55 ℃ in step 5.

6. The tar residue treatment method according to claim 1, further comprising a step 6 of mixing the tar of the step 4 with the tar cooled in the step 5, and naturally settling to remove water to obtain crude tar; and distilling the crude tar by using a rectifying tower to separate light oil, heavy oil, residual oil and water.