Integrated tar distillation method

Abstract

The integrated tar distillation method is characterized in that a tar distillation tower, an industrial naphthalene distillation tower and an asphalt reaction kettle are integrally arranged, and the integrated tar distillation method is characterized by comprising the following steps: a, raw material tar pressurized and sent by a raw material tank group through a tar pump is subjected to heat exchange through three-mixed oil, anthracene oil and medium-temperature modified asphalt and then enters a tar dehydration tower; b, the dehydrated anhydrous tar is pumped out from the bottom of the tower by an anhydrous tar pump, and a part of the dehydrated anhydrous tar is subjected to heat exchange through the anhydrous tar and high-temperature modified pitch heat exchanger and then enters a tar dehydrating tower, c, three-mixed oil is distilled out from the top of the tar distillation tower, d, anthracene oil is extracted from the top and the middle of the anthracene tower, and e, in a pitch reaction kettle, the anthracene oil is extracted from the top of the anthracene tower and the middle of the anthracene tower. The medium-temperature modified asphalt is produced from the medium-temperature asphalt through long-time standing polymerization reaction. The integrated tar distillation method has the advantages that energy consumption and carbon emission are reduced, energy consumption is reduced, heat loss is reduced, the occupied area is saved by about 30%, and energy consumption is saved by 46.7% compared with the standard energy consumption.

Description

Technical Field

[0001] The invention belongs to the technical field of coal tar processing, and specifically, is an integrated tar distillation method. Background Art

[0002] Coal tar is a by-product of the coking process, which is condensed from coking coal gas. Coal tar contains nearly 10,000 kinds of organic compounds, most of which are aromatic compounds and are important chemical raw materials. In 2023, my country's coal tar production reached 26.94 million tons. Usually, coal tar is first divided into light oil, phenol oil, naphthalene oil, washing oil, anthracene oil and asphalt through distillation, and then refined. Typical tar continuous distillation processes include atmospheric distillation, vacuum distillation and atmospheric and vacuum distillation processes.

[0003] The vacuum distillation process consists of dehydration and fraction distillation. That is, dehydration is carried out under normal pressure, and the dehydrated anhydrous tar is subjected to vacuum distillation in the fraction tower. The fractions of vacuum distillation are generally narrow fractions, that is, phenol oil, naphthalene oil, and washing oil are extracted separately. The temperature at the top of the tower is low, and the heat cannot be fully utilized. At the same time, for the convenience of operation, tar distillation and modified asphalt are generally arranged separately. The soft asphalt is cooled and stored before entering the modified asphalt, and then heated after entering the modified asphalt, resulting in a large waste of energy. Since tar distillation and modified asphalt are distributed in different areas, the entire tar processing occupies a huge area.

[0004] The conventional tower configuration of tar distillation and modified asphalt is a dehydration tower, a tar distillation tower, anthracene tower, an asphalt reactor, and a modification tower, with a total of 5 towers. The large number of towers makes the operation complex and occupies a large area. Modified asphalt has high viscosity and high temperature, and the pump used for transportation often needs to be repaired during operation, which makes the operation difficult.

[0005] Therefore, the known tar distillation configuration has the above-mentioned inconveniences and problems. Summary of the invention

[0006] The purpose of the present invention is to provide an integrated tar distillation method which integrates a dehydration tower, a tar distillation tower and a reforming tower.

[0007] To achieve the above purpose, the technical solution of the present invention is: An integrated tar distillation method, wherein a tar distillation tower, an industrial naphthalene distillation tower, and an asphalt reactor are arranged in an integrated manner, characterized in that the method comprises the following steps: a. The raw tar, which is pressurized by the tar pump and sent from the raw material tank group, is heat exchanged with three-mixed oil, anthracene oil and medium-temperature modified asphalt, and then enters the tar dehydration tower; light oil and water evaporate from the top of the tar dehydration tower, and after condensation and cooling in the light oil condensation cooler, they are sent to the oil-water separation tank for oil-water separation; the light oil separated in the oil-water separation tank is pressurized by the light oil delivery pump, and part of it returns to the tar dehydration tower, and the other part is sent to the light oil tank of the product tank group for storage; the phenol-containing wastewater separated from the bottom of the oil-water separation tank flows by gravity to the wastewater tank of the raw material tank group; b. The dehydrated anhydrous tar is pumped out from the bottom of the tower by an anhydrous tar pump. One part of it enters the tar dehydration tower after heat exchange with the high-temperature modified asphalt heat exchanger to supply heat to the tar dehydration tower; the other part is sent to the tar distillation tower after heat exchange with the anhydrous tar / light oil heat exchanger and modified asphalt light oil; c. In the tar distillation tower, the three-mixed oil evaporated from the top of the tower is heat exchanged with the raw tar and the three-mixed oil heat exchanger and the raw tar, and then cooled by the three-mixed oil cooler, and then enters the three-mixed oil tank, and then is pressurized by the three-mixed oil delivery pump, and a part is sent to the industrial naphthalene distillation tower, and a part is returned to the top of the tar distillation tower as a tower top reflux; the soft asphalt at the bottom of the tower is pressurized by the tar distillation tower circulation pump, a part of it is heated by the tar heating furnace as a heat source of the tar distillation tower, and the other part is sent to the anthracene tower for further distillation; d. In the anthracene tower, anthracene oil is produced at the top and the middle of the tower; the anthracene oil at the top of the tower is subjected to heat exchange with the raw material tar in the tar and anthracene oil heat exchanger, and then cooled in the anthracene oil condenser cooler before entering the anthracene oil tank, and then a part of it is sent to the finished product tank group through the anthracene oil delivery pump, and the other part is sent back to the top of the anthracene tower as anthracene oil tower top reflux; the anthracene oil in the middle of the tower is produced through the side line and cooled in the anthracene oil cooler, and then enters the anthracene oil tank, and then a part of it is sent to the finished product tank group through the anthracene oil delivery pump, and the other part is returned to the middle of the anthracene tower as the middle tower reflux; the medium-temperature asphalt produced in the kettle of the anthracene tower is pressurized by the bottom pump of the anthracene tower, and a part of it is heated by the anthracene oil heating furnace and returned to the anthracene tower as the anthracene tower hot oil, and the rest enters the asphalt reactor; e. In the asphalt reactor, the medium-temperature asphalt is subjected to a long-term static polymerization reaction to produce medium-temperature modified asphalt; after the modified asphalt in the asphalt reactor is pressurized by the medium-temperature modified asphalt product pump, a part of the medium-temperature modified asphalt is sent to the anhydrous tar and medium-temperature modified asphalt heat exchanger for cooling, and then sent to the asphalt tank group for storage, and the other part is heated by the asphalt heating furnace to supplement the heat of the asphalt reactor; the remaining part of the modified asphalt is sent to the modification tower, flashed under vacuum conditions, and the flashed modified oil is heat-exchanged by the anhydrous tar / light oil heat exchanger, and the modified oil after heat exchange is cooled and sent to the anthracene oil tank. The high-temperature modified asphalt at the bottom of the modification tower is heat-exchanged by the anhydrous tar / asphalt heat exchanger and sent to the modified asphalt tank.

[0008] The integrated tar distillation method of the present invention can also be further implemented by adopting the following technical measures.

[0009] In the above method, the anthracene oil is extracted from the top and the middle of the anthracene tower respectively, and the anthracene oils with different compositions are stored separately; if it is not necessary to store the anthracene oils with different compositions separately, the anthracene oils with different compositions are mixed and then enter the anthracene oil storage tank. After adopting the above technical solution, the integrated tar distillation method of the present invention has the following advantages: 1. The gas phase three-mixed fraction is extracted from the top of the tar distillation tower, and the three-mixed fraction is fully heat-exchanged with the raw material tar to reduce energy consumption and carbon emissions; 2. Hot-mix operation of tar distillation and modified asphalt can reduce energy consumption through sufficient heat exchange; 3. The integrated layout of tar distillation, industrial naphthalene distillation and modified asphalt reduces heat loss and saves about 30% of land; 4. The comprehensive energy consumption of tar processing can reach 40kgce / t tar. According to Article 6.1.3 of the "Design Standard for Coal Coking Tar Processing Engineering" (GB / T51331-2018), the unit product energy consumption of coal tar processing engineering should not exceed 75kgce / t tar, which saves 46.7% compared with the standard energy consumption; 5. The dehydration tower, tar distillation tower and modification tower are integrated into a tar distillation tower, which not only saves floor space, but also reduces equipment investment. At the same time, it solves the problem of difficult transportation of modified asphalt. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is a flow chart of an integrated tar processing energy-saving process with top mining, three-mixing and sufficient heat exchange according to an embodiment of the present invention; Figure 2 It is a schematic diagram of another integrated arrangement of a tar distillation tower, an industrial naphthalene distillation tower, and an asphalt reactor according to an embodiment of the present invention; Figure 3 It is a schematic diagram of the integrated arrangement of a tar distillation tower, an industrial naphthalene distillation tower, and an asphalt reactor according to an embodiment of the present invention. DETAILED DESCRIPTION

[0011] The present invention is further described below in conjunction with embodiments and accompanying drawings. Example

[0012] Please refer to Figures 1 to 3 The integrated tar distillation method of the present invention comprises the following steps: 1. The raw tar sent by the raw material tank group through the tar pump is pressurized and then heat-exchanged with three-mixed oil, anthracene oil, and medium-temperature modified asphalt, and then enters the tar dehydration tower. Light oil and water evaporate from the top of the tar dehydration tower, and after condensation and cooling in the light oil condensation cooler, they are sent to the oil-water separation tank for oil-water separation. The light oil separated in the oil-water separation tank is pressurized by the light oil delivery pump, and part of it returns to the tar dehydration tower, and the other part is sent to the light oil tank of the product tank group for storage. The phenol-containing wastewater separated from the bottom of the oil-water separation tank flows by gravity to the wastewater tank of the raw material tank group.

[0013] 2. The dehydrated anhydrous tar is pumped out from the bottom of the tower by an anhydrous tar pump. One part enters the tar dehydration tower after heat exchange between anhydrous tar and high-temperature modified asphalt heat exchanger to supply heat to the tar dehydration tower; the other part is sent to the tar distillation tower after heat exchange between anhydrous tar / light oil heat exchanger and modified asphalt light oil.

[0014] 3. In the tar distillation tower, the three-mixed oil evaporated from the top of the tower is heat exchanged with the raw tar and the three-mixed oil heat exchanger, and then cooled by the three-mixed oil cooler, and then enters the three-mixed oil tank, and then pressurized by the three-mixed oil delivery pump, part of which is sent to industrial naphthalene distillation, and part of which returns to the top of the tar distillation tower as the top reflux. The soft asphalt at the bottom of the tower is pressurized by the tar distillation tower circulation pump, part of which is heated by the tar heating furnace as the heat source of the tar distillation tower, and the other part is sent to the anthracene tower for further distillation.

[0015] In the anthracene tower, anthracene oil is produced from the top and middle of the tower. The anthracene oil at the top of the tower is heat exchanged with the raw tar in the tar and anthracene oil heat exchanger, and then cooled in the anthracene oil condenser cooler before entering the anthracene oil tank. Then, part of it is sent to the finished product tank group through the anthracene oil delivery pump, and the other part is sent back to the top of the anthracene tower as anthracene oil top reflux. Similarly, the anthracene oil in the middle of the tower is produced through the side line and cooled in the anthracene oil cooler before entering the anthracene oil tank. Then, part of it is sent to the finished product tank group through the anthracene oil delivery pump, and the other part is returned to the middle of the anthracene tower as the middle tower reflux. The medium-temperature asphalt produced in the anthracene tower kettle is pressurized by the anthracene tower bottom pump, and part of it is heated by the anthracene oil heating furnace and returned to the anthracene tower as anthracene tower hot oil, and the rest enters the asphalt reactor.

[0016] 4. Anthracene oil is extracted from the top and middle of the anthracene tower respectively. The extracted anthracene oil has different components. If it does not need to be stored separately, it can be mixed and put into the anthracene oil storage tank at the same time. There are two advantages of this setting. First, the tower has been used in many projects, and the operating parameters and structure are very mature and there is no risk. Second, if the refined anthracene facilities are added later, it is very easy to achieve.

[0017] 5. In the asphalt reactor, the medium-temperature asphalt is subjected to a long-term static polymerization reaction to produce medium-temperature modified asphalt. After the modified asphalt in the asphalt reactor is pressurized by the medium-temperature modified asphalt product pump, a part of the medium-temperature modified asphalt is sent to the anhydrous tar and medium-temperature modified asphalt heat exchanger for cooling, and then sent to the asphalt tank group for storage, and the other part is heated by the asphalt heating furnace to supplement the heat of the asphalt reactor; the remaining part of the modified asphalt is sent to the modification tower, flashed under vacuum conditions, and the flashed modified oil is heat-exchanged by the anhydrous tar / light oil heat exchanger. The modified oil after heat exchange is cooled and sent to the anthracene oil tank. The high-temperature modified asphalt at the bottom of the modification tower is heat-exchanged by the anhydrous tar / asphalt heat exchanger and sent to the modified asphalt tank.

[0018] The present invention has substantial characteristics and significant technical progress. The integrated tar distillation method of the present invention integrates the dehydration tower, the tar distillation tower and the reforming tower into an integrated tar distillation tower. The reforming tower is located at the top and is directly sent to the reformed asphalt tank after gravity heat exchange, which can reduce the asphalt pump. Tar distillation, industrial naphthalene distillation and reformed asphalt are arranged in an integrated manner to reduce heat loss and save space. After tar distillation and reformed asphalt are arranged together, tar distillation can make full use of the heat of reformed asphalt.

[0019] The integrated tar distillation method of the present invention is used in the tar distillation project of Baotou Baokai Carbon Material Co., Ltd. with remarkable effect. The national standard stipulates that the unit product energy consumption of coal tar processing engineering should not be greater than 75kgce / t tar. Compared with the standard energy consumption, the present invention saves 46.7%.

[0020] The above embodiments are only for the purpose of illustrating the present invention, but not for limiting the present invention. A person skilled in the art may make various changes or modifications without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should also belong to the scope of the present invention and should be defined by the claims.

Claims

1. An integrated tar distillation method, wherein a tar distillation tower, an industrial naphthalene distillation tower, and an asphalt reactor are arranged in an integrated manner, characterized in that The following steps are involved: a. The raw tar, which is pressurized by the tar pump and sent from the raw material tank group, is heat exchanged with three-mixed oil, anthracene oil and medium-temperature modified asphalt, and then enters the tar dehydration tower; light oil and water evaporate from the top of the tar dehydration tower, and after condensation and cooling in the light oil condensation cooler, they are sent to the oil-water separation tank for oil-water separation; the light oil separated in the oil-water separation tank is pressurized by the light oil delivery pump, and part of it returns to the tar dehydration tower, and the other part is sent to the light oil tank of the product tank group for storage; the phenol-containing wastewater separated from the bottom of the oil-water separation tank flows by gravity to the wastewater tank of the raw material tank group; b. The dehydrated anhydrous tar is pumped out from the bottom of the tower by an anhydrous tar pump. One part of it enters the tar dehydration tower after heat exchange with the high-temperature modified asphalt heat exchanger to supply heat to the tar dehydration tower; the other part is sent to the tar distillation tower after heat exchange with the anhydrous tar / light oil heat exchanger and modified asphalt light oil; c. In the tar distillation tower, the three-mixed oil evaporated from the top of the tower is heat exchanged with the raw tar and the three-mixed oil heat exchanger and the raw tar, and then cooled by the three-mixed oil cooler, and then enters the three-mixed oil tank, and then is pressurized by the three-mixed oil delivery pump, and a part is sent to the industrial naphthalene distillation tower, and a part is returned to the top of the tar distillation tower as a tower top reflux; the soft asphalt at the bottom of the tower is pressurized by the tar distillation tower circulation pump, a part of it is heated by the tar heating furnace as a heat source of the tar distillation tower, and the other part is sent to the anthracene tower for further distillation; d. In the anthracene tower, anthracene oil is produced at the top and the middle of the tower; the anthracene oil at the top of the tower is subjected to heat exchange with the raw material tar in the tar and anthracene oil heat exchanger, and then cooled in the anthracene oil condenser cooler before entering the anthracene oil tank, and then a part of it is sent to the finished product tank group through the anthracene oil delivery pump, and the other part is sent back to the top of the anthracene tower as anthracene oil tower top reflux; the anthracene oil in the middle of the tower is produced through the side line and cooled in the anthracene oil cooler, and then enters the anthracene oil tank, and then a part of it is sent to the finished product tank group through the anthracene oil delivery pump, and the other part is returned to the middle of the anthracene tower as the middle tower reflux; the medium-temperature asphalt produced in the kettle of the anthracene tower is pressurized by the bottom pump of the anthracene tower, and a part of it is heated by the anthracene oil heating furnace and returned to the anthracene tower as the anthracene tower hot oil, and the rest enters the asphalt reactor; e. In the asphalt reactor, the medium-temperature asphalt is subjected to a long-term static polymerization reaction to produce medium-temperature modified asphalt; after the modified asphalt in the asphalt reactor is pressurized by the medium-temperature modified asphalt product pump, a part of the medium-temperature modified asphalt is sent to the anhydrous tar and medium-temperature modified asphalt heat exchanger for cooling, and then sent to the asphalt tank group for storage, and the other part is heated by the asphalt heating furnace to supplement the heat of the asphalt reactor; the remaining part of the modified asphalt is sent to the modification tower, flashed under vacuum conditions, and the flashed modified oil is heat-exchanged by the anhydrous tar / light oil heat exchanger, and the modified oil after heat exchange is cooled and sent to the anthracene oil tank; The high-temperature modified asphalt at the bottom of the modifying tower is sent to the modified asphalt tank after heat exchange through the anhydrous tar / asphalt heat exchanger.

2. The integrated tar distillation method according to claim 1, characterized in that: The anthracene oil with different components is respectively extracted from the top and the middle of the anthracene tower; if it is not necessary to store the anthracene oil with different components separately, the anthracene oil with different components is mixed and then enters the anthracene oil storage tank.

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