Resource recycling method for tar residue of coal tar

Abstract

The invention provides a coal tar residue resource recycling method, and relates to the technical field of coal chemical industry tar residue resource utilization, the coal tar residue resource recycling method comprises the following steps: S1, mixing: mixing tar residue with a solvent according to a mass ratio to obtain mixed oil A; s2, dehydration: transferring the mixed oil A to a distillation kettle for dehydration, and stopping distillation when water is distilled until no reflux exists, so as to obtain mixed oil B; s3, dissolving and filtering: heating the mixed oil B, dissolving and filtering by using a screen; and S4, blending and recycling: blending the recycled tar residue with the heavy coal pitch. And S5, preparing pitch coke: carrying out delayed coking on the sample mixed and recycled in the step S4 to prepare the pitch coke. The tar residue is dissolved and recovered through the solvent and then is mixed with the heavy coal pitch in different proportions, so that the disposal cost and the environmental protection cost can be reduced, the economic benefit can be effectively improved by mixing the tar residue with the heavy coal pitch, and more benefits can be created for enterprises.

Description

Technical Field

[0001] The invention relates to the technical field of resource utilization of coal chemical tar residues, and in particular to a method for utilizing the recovery rate of coal tar tar residues. Background Art

[0002] In the coal chemical production process, high-boiling organic compounds condense to form coal tar. At the same time, coal powder, coke powder and ash entrained in the coal gas are mixed in the coal tar to form lumps of varying sizes, called tar residue. Tar residue is a viscous solid waste residue adsorbed with coal tar. It mainly comes from mechanized ammonia clarification tanks, tar ammonia separators, super centrifuges and tar storage tanks. Its main components are polycyclic aromatic hydrocarbons, phenols, naphthalene and other toxic carcinogens. It is extremely viscous at room temperature and difficult to use directly. The current treatment methods include coal coking; use as fuel; carbon-making materials, which are all good resource utilization and save solid waste treatment costs for enterprises. However, there are also shortcomings. Tar residue is directly coked with coal, and the energy utilization rate is not maximized; the use of tar residue as fuel oil will emit a large amount of pollutants such as nitrogen oxides and sulfur dioxide; carbon-making materials are more harmful to belts and equipment during transportation and production. Therefore, it is necessary to develop a new method to utilize tar residue as a resource.

[0003] For this reason, some companies that prepare coal-based needle coke use high-temperature coal tar to prepare needle coke. First, the high-temperature coal tar is pre-treated and dehydrated, and the light fraction oil is cut off through a distillation tower to obtain soft asphalt. The soft asphalt is refined into coking raw materials, and needle coke is prepared through coking. During the pre-treatment and dehydration stage of high-temperature coal tar, tar residue will be separated. The tar residue produced by the separation of high-temperature coal tar is mainly composed of aromatic-rich heavy oil and coal residue. Tar residue is usually incinerated as solid waste, but because tar residue contains 30% to 40% coal tar, coal tar loss is caused with tar incineration, which reduces product revenue and also causes resource waste. Summary of the invention

[0004] Taking into account the disposal cost and environmental protection cost of the solution proposed in the background technology, the purpose of the present invention is to recycle tar residue to reduce costs, protect the environment, and recover resources through this solution to improve economic benefits.

[0005] The technical solution adopted by the embodiment of the present application to solve the technical problem is:

[0006] A method for utilizing the recovery rate of coal tar tar residues comprises the following steps:

[0007] S1. Mixing: Mixing the tar residue and the solvent in a mass ratio to obtain a mixed oil A;

[0008] S2. Dehydration: The mixed oil A is transferred to a distillation kettle for dehydration. When the water is distilled to no reflux, the distillation is stopped to obtain the mixed oil B;

[0009] S3. Dissolution and filtration: The mixed oil B is heated, dissolved and filtered using a mesh;

[0010] S4. Mixing and recovery: Mix the recovered tar residue with heavy coal tar pitch at a ratio of 10:1-30:1.

[0011] S5. Preparation of pitch coke: The sample recovered from the mixing step S4 is subjected to delayed coking to prepare pitch coke.

[0012] According to some embodiments of the present application, in step S1, the solvent is at least one of anthracene oil, wash oil, and circulating oil.

[0013] According to some embodiments of the present application, in step S1, the tar residue and the solvent are mixed in a mass ratio of 1:0.2 to 1.5.

[0014] According to some embodiments of the present application, in step S2, the mixed oil A is transferred to a distillation kettle for dehydration at 105-125°C.

[0015] According to some embodiments of the present application, in step S3, the mixed oil B is heated to 120-160° C. and dissolved for 20-60 minutes.

[0016] According to some embodiments of the present application, in step S3, the mixed oil B is filtered using a sieve with a mesh size of 40 to 200.

[0017] The advantages of the embodiments of the present application are:

[0018] High-temperature coal tar tar residue is generally used for solid waste incineration, and its value is relatively low. Considering the disposal cost and environmental protection cost, the present invention recovers by dissolving, using different solvents, and can dissolve tar residue well at a certain proportion to recover coal tar, and mixes with heavy coal tar in different proportions, adjusts the softening point index, and sells it domestically or at the price of heavy coal tar to improve economic benefits. According to the solvent used in the present invention, an economic benefit analysis is conducted. According to a 150,000-ton coal tar processing device, tar residue accounts for about 0.4%, and the minimum annual revenue can be about 2.688 million yuan. If this technology is promoted nationwide, the coal tar production capacity will be 27 million tons in 2022, and it will generate about 627.938 million yuan in revenue each year, which will not only protect the environment, reduce disposal and environmental protection costs, but also generate revenue for enterprises. At the same time, the amount of solid waste incineration treatment is reduced, and carbon emissions are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments of the present application will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0020] Figure 1 A flow chart of a method for utilizing the recovery rate of coal tar tar residue provided in an embodiment of the present application. DETAILED DESCRIPTION

[0021] The technical solutions in the embodiments of the present application will be described below in conjunction with the drawings in the embodiments of the present application.

[0022] In order to make the purpose, technical solutions and advantages of the implementation methods of this application clearer, the technical solutions in the implementation methods of this application will be clearly and completely described below in conjunction with the drawings in the implementation methods of this application. Obviously, the described implementation methods are part of the implementation methods of this application, not all of the implementation methods. Based on the implementation methods in this application, all other implementation methods obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0023] The tar residue and the solvent are mixed in different mass ratios, the dissolution temperature is controlled, and the sieve mesh is filtered to separate them. The specific implementation cases are as follows:

[0024] The physical and chemical properties of the crude oil are as follows:

[0025] Table 1 Distillation range data of anthracene oil, wash oil and cycle oil

[0026]

[0027]

[0028] Implementation Case 1

[0029] like Figure 1 As shown, a method for utilizing the recovery rate of coal tar tar residue comprises the following steps:

[0030] Tar residue and anthracene oil are prepared in a dissolving tank in a ratio of 1:0.8 (anthracene oil refers to a compound with an aromatic hydrocarbon structure extracted from coal tar), heated to dissolve each other until the fluidity is good, and then transferred to a distillation kettle. The mixed solution prepared by the atmospheric distillation dehydration device is used to remove water. The temperature of the heater is controlled at 125°C. When the water is distilled to no reflux, the distillation is stopped, and the heating and stirring device is switched to dissolve and heated to 155°C for 60 minutes. The 40-mesh screen is used for filtration, and the undersize and oversize are weighed separately, and the recovery rate is calculated. The recovery rate of tar residue reaches 94.61%, and the proportion of coke residue in tar residue is 3.27%. The selection of anthracene oil to dissolve tar residue can dissolve tar residue well at a certain mass ratio for recycling, saving costs. The dissolved and recovered tar residue and heavy coal tar pitch were mixed in a ratio of 20:1. The physical and chemical indicators of the heavy coal tar pitch showed little difference, and the softening point difference could be adjusted by following the mixing ratio. The delayed coking device was used to control the pressure, temperature and other parameters to prepare asphalt coke, and the product fully met the requirements of asphalt coke. The results are shown in Table 2.

[0031] The above technology uses coal tar tar residue as raw material, dissolves and filters it through a variety of aromatic-rich oils, and can recover coal tar to separate coal powder and other residues, thereby recycling resources very well. At the same time, the dissolved coal tar can also regulate the softening point of heavy coal tar, thereby achieving resource reuse and maximizing economic benefits.

[0032] Implementation Case 2

[0033] like Figure 1 As shown, a method for utilizing the recovery rate of coal tar tar residue comprises the following steps:

[0034] Tar residue and washing oil are prepared in a dissolving tank at a ratio of 1:0.8 (washing oil is an absorption oil used to wash out benzene or naphthalene compounds from coal gas), heated and dissolved until the fluidity is good, and then transferred to a distillation kettle. The mixed solution prepared by the atmospheric distillation dehydration device is used to remove water. The temperature of the heater is controlled at 125°C. When the water is distilled to no reflux, the distillation is stopped, and the heating stirring device is switched to dissolve and heated to 155°C for 60 minutes. The 40-mesh screen is used for filtration, and the undersize and oversize are weighed separately, and the recovery rate is calculated. The coke residue accounts for only 1.9%, and the recovery rate of the tar residue reaches 92.72%. At this ratio, it is prepared with heavy coal tar pitch at a ratio of 30:1. The physical and chemical indicators of the heavy coal tar pitch change little, and the softening point difference can be adjusted with the preparation ratio. The pressure, temperature and other parameters are controlled by the delayed coking device to prepare asphalt coke. The product fully meets the requirements of asphalt coke. The results are shown in Table 2.

[0035] The above technology uses coal tar tar residue from the company's solid waste incineration as raw material, dissolves and filters it through a variety of aromatic-rich oils, and can recover coal tar and separate coal powder and other residues, thus recycling resources very well. At the same time, the dissolved coal tar can also regulate the softening point of heavy coal tar, achieving resource reuse and maximizing economic benefits.

[0036] Implementation Case 3

[0037] like Figure 1 As shown, a method for utilizing the recovery rate of coal tar tar residue comprises the following steps:

[0038] Tar residue and circulating oil are prepared in a dissolution tank in a 1:1 ratio (circulating oil is a kind of light oil product, which is processed by a primary processing atmospheric and vacuum device, a secondary processing of catalytic cracking, an intermediate distillate oil, and a desulfurization device). They are heated to dissolve each other until the fluidity is good, and then transferred to a distillation kettle. The mixed solution prepared by a normal pressure distillation dehydration device is used to remove water. The temperature of the heater is controlled at 125°C. When the water is distilled to no reflux, the distillation is stopped and the heating and stirring device is switched to dissolve and the temperature is raised to 155°C for dissolution for 60 minutes. Using a 40-mesh sieve to filter, the undersize and oversize materials were weighed separately, and the recovery rate was calculated. The coke residue accounted for only 2.89%, and the tar recovery rate reached 94.24%. At this ratio, it was mixed with heavy coal tar in a ratio of 10:1. The physical and chemical indicators of the heavy coal tar were slightly different, and the softening point difference could be adjusted with the mixing ratio. The delayed coking device was used to control parameters such as pressure and temperature to prepare asphalt coke, and the product fully met the requirements of asphalt coke. The results are shown in Table 2.

[0039] The above technology uses coal tar tar residue as raw material, dissolves and filters it through a variety of aromatic-rich oils, and can recover coal tar to separate coal powder and other residues, thereby recycling resources very well. At the same time, the dissolved coal tar can also regulate the softening point of heavy coal tar, thereby achieving resource reuse and maximizing economic benefits.

[0040] Comparative Example 1

[0041] Pure heavy coal tar pitch was subjected to delayed coking to prepare asphalt coke, and the experimental parameters were controlled to be the same as those in Example 1, Example 2, and Example 3, and the test results of the prepared green coke were shown in Table 2. Compared with Example 1, Example 2, and Example 3, different solvents were used to dissolve the tar residue, and the recovered mother liquor was prepared with heavy coal tar pitch in a certain ratio and applied to the preparation of asphalt coke. The prepared product was compared with Comparative Example 1, and the results were almost the same, which provided a good method for regenerating coal tar residue.

[0042] Table 2 Needle coke coking monitoring and analysis data

[0043] Test items Comparative Example 1 Embodiment 1 Embodiment 2 Embodiment 3 Moisture,% 0.21 0.18 0.20 0.22 Ash content, % 0.02 0.01 0.01 0.02 Volatile matter, % 5.19 6.32 6.48 5.72 <![CDATA[True density, (g / cm 3 )]]> 1.479 1.458 1.466 1.488 sulfur,% 0.44 0.46 0.44 0.42 nitrogen,% 0.49 0.51 0.41 0.35

[0044] Economic benefit analysis of the present invention: high-temperature coal tar tar residue is generally used for solid waste incineration and has a low value. Considering the disposal cost and environmental protection cost, the present invention recovers by dissolving and using different solvents. The tar residue can be well dissolved in a certain proportion to recover coal tar, and mixed with heavy coal tar pitch in different proportions, and the softening point index is adjusted. The heavy coal tar pitch price is used for domestic sales to prepare asphalt coke or sell it to improve economic benefits. The economic benefit analysis is carried out according to the solvent used in the present invention. According to the 150,000-ton coal tar processing device, the tar residue accounts for about 0.4%, and about 600 tons of tar residue are produced each year. The tar residue is dissolved with anthracene oil, wash oil, and circulating oil respectively. The economic benefits are calculated according to the yield and the heavy coal tar pitch in different proportions:

[0045] The unit price of anthracene oil is about 3,950 yuan / ton, generating annual revenue of about 2.852 million yuan;

[0046] The unit price of wash oil is about 4,050 yuan / ton, generating annual revenue of about 2.688 million yuan;

[0047] The unit price of circulating oil is about 2,900 yuan / ton, generating annual revenue of about 3.489 million yuan.

[0048] Regardless of the solvent, it can bring considerable benefits. If the technology is promoted nationwide, the coal tar production capacity will be 27 million tons in 2022. Using recycled oil as solvent, it will generate annual revenue of about 627.938 million yuan. It will not only protect the environment, reduce disposal and environmental protection costs, but also generate economic income for enterprises.

[0049] In summary, tar residue is recovered by solvent dissolution and mixed with heavy coal tar in different proportions, which can not only reduce disposal costs and environmental protection costs, but also effectively improve economic benefits by mixing with heavy coal tar, thus creating more benefits for the enterprise.

[0050] Finally, it should be noted that: Obviously, the above embodiments are only examples for clearly explaining the present application, and are not intended to limit the implementation methods. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived from this are still within the scope of protection of the present application.

Claims

1. A method for utilizing the recovery rate of coal tar tar residue, It is characterized in that The steps include: S1. Mixing: Mixing the tar residue and the solvent in a mass ratio to obtain a mixed oil A; S2. Dehydration: The mixed oil A is transferred to a distillation kettle for dehydration. When the water is distilled to no reflux, the distillation is stopped to obtain the mixed oil B; S3. Dissolution and filtration: The mixed oil B is heated, dissolved and filtered using a mesh; S4. Mixing and recovery: Mix the recovered tar residue with heavy coal tar pitch at a ratio of 10:1-30:

1. S5. Preparation of pitch coke: The sample recovered from the mixing step S4 is subjected to delayed coking to prepare pitch coke.

2. The method for utilizing the recovery rate of coal tar tar residue as claimed in claim 1, It is characterized in that In the step S1, the solvent is at least one of anthracene oil, wash oil, and circulating oil.

3. The method for utilizing the recovery rate of coal tar tar residue as claimed in claim 1, It is characterized in that In the step S1, the tar residue and the solvent are mixed in a mass ratio of 1:0.2 to 1.

5.

4. The method for utilizing the recovery rate of coal tar tar residue as claimed in claim 1, It is characterized in that In the step S2, the mixed oil A is transferred to a distillation kettle for dehydration at 105-125°C.

5. The method for utilizing the recovery rate of coal tar tar residue as claimed in claim 1, It is characterized in that In step S3, the mixed oil B is heated to 120-160° C. and dissolved for 20-60 minutes.

6. The method for utilizing the recovery rate of coal tar tar residue as claimed in claim 1, It is characterized in that In the step S3, the mixed oil B is filtered using a 40-200 mesh sieve.

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