CN111849565A

CN111849565A - Novel debenzolization tower for coking chemical products

Info

Publication number: CN111849565A
Application number: CN201910891303.XA
Authority: CN
Inventors: 李波; 李婵; 李凯; 侯建国; 李斌; 宋亚波; 李幸
Original assignee: Pingxiang Huaxing Environmental Protection Engineering Technology Co ltd
Current assignee: Pingxiang Huaxing Environmental Protection Engineering Technology Co ltd
Priority date: 2019-09-20
Filing date: 2019-09-20
Publication date: 2020-10-30

Abstract

The invention relates to the field of crude benzene distillation equipment of rich oil in the coking industry, and provides a novel debenzolization tower for coking chemical production, wherein a method of reduced pressure or negative pressure steam stripping is adopted, an oil gas inlet is designed on the tower, so that hot lean oil flowing out of a lean oil outlet is used as a heat source and enters the debenzolization tower again from the oil gas inlet, the dependence on the steam used as the heat source is greatly reduced, the superheated steam introduced into the debenzolization tower is obviously reduced, and the wastewater amount is reduced; an oil return port is designed, so that an oil-water mixture flowing out of an oil-water outlet enters the rectification section again from the oil return port after oil-water separation, and is subjected to desorption rectification again, and the recovery rate of benzene and naphthalene oil is improved; the tower body is also provided with a plurality of temperature monitoring ports for respectively detecting the temperature of each naphthalene oil collecting port, which is favorable for mastering the temperature distribution in the rectifying section, timely adjusts the heat source entering the tower and ensures the naphthalene oil collecting quality.

Description

Novel debenzolization tower for coking chemical products

Technical Field

The invention relates to the field of crude benzene distillation equipment for rich oil in coking industry, in particular to a novel debenzolization tower for coking chemical products.

Background

In the coking industry, coke oven gas generated in the coal coking process generally contains about 25-35g/Nm of benzene ³The benzene content after recovery is usually 0.4 to 0.6%. In order to better recycle the crude benzene, the benzene hydrocarbon in the coal gas is recycled by washing and absorbing equipment and using high-boiling-point wash oil as a washing and absorbing agent, the wash oil is changed into rich oil after absorbing the benzene, then the rich oil is distilled to separate out the crude benzene, and the rich oil is changed into the wash oil or called lean oil after being distilled and debenzolized. Most of the domestic debenzolization processes mainly adopt a method of reduced pressure or negative pressure steam stripping, high-temperature steam is used as a heat source, the partial pressure of oil steam is reduced, the gasification temperature of the benzene hydrocarbon in rich oil is reduced, and components such as crude benzene, naphthalene oil and the like are stripped and evaporated at a lower temperature. However, in the prior art, the same amount of waste water containing harmful substances of phenols is generated by water vapor, the waste water is difficult to treat, the treatment cost is very high, and the defects of low quality of recovered products, low recovery rate, high production consumption and the like exist.

Disclosure of Invention

The invention aims to solve the technical problem of providing a novel debenzolization tower for coking chemical products, which can reduce the consumption of water vapor and effectively improve the quality and the recovery efficiency of recovered products.

The technical scheme of the invention is that a novel debenzolization tower produced by coking is provided, which comprises a tower body, wherein the tower body is formed by connecting a rectifying section at the upper part and a stripping section at the lower part, a sealing cover is arranged at the top of the rectifying section, a tower kettle is arranged at the bottom of the stripping section, the tower kettle is arranged on a skirt, a plurality of layers of tower trays or fillers are arranged in the tower body of the rectifying section and the stripping section, an oil-rich inlet is arranged on the side wall of the tower body at the connecting part of the rectifying section and the stripping section, an oil-gas inlet and an overheated steam inlet are arranged on the side wall of the tower body below the tower trays or the fillers in the stripping section, a lean oil outlet is arranged at the bottom of the tower kettle, a tower bottom pressure gauge interface and a tower bottom thermometer interface are arranged at the lower part of the stripping section; a plurality of naphthalene oil side line outlets are formed in the tower wall in the middle of the rectifying section, each naphthalene oil side line outlet is connected with a corresponding tower disc layer or a corresponding packing layer, and a thermometer interface is arranged at the position corresponding to each naphthalene oil outlet; a crude benzene reflux port, an oil return port and an oil-water outlet are formed in the tower wall at the upper part of the rectifying section, a gas-phase communication hole is formed in the tower wall above the oil-water outlet, the oil-water outlet and the crude benzene reflux port are respectively connected with the uppermost tower disc layer or the packing layer, and the oil return port is connected with the tower disc layer or the packing layer below the crude benzene reflux port; the sealing cover is provided with a benzene steam outlet and a diffusing port, and the sealing cover is also provided with a tower top pressure interface and a tower top temperature interface.

Compared with the prior art, the invention has the following advantages:

the novel debenzolization tower for coking and chemical production adopts a method of reduced pressure or negative pressure steam stripping, and is also provided with an oil gas inlet, so that hot lean oil flowing out of a lean oil outlet is used as a heat source and enters the debenzolization tower again from the oil gas inlet, the dependence on the steam used as the heat source is greatly reduced, the superheated steam introduced into the debenzolization tower is obviously reduced, and the amount of wastewater is reduced; an oil return port is also designed, so that an oil-water mixture flowing out of the oil-water outlet enters the rectification section again from the oil return port after oil-water separation, and is subjected to desorption rectification again, and the recovery rate of benzene and naphthalene oil is improved; the tower body of the novel debenzolization tower for coking and chemical production is provided with a plurality of temperature monitoring ports for respectively detecting the temperature of each naphthalene oil collecting port, which is favorable for mastering the temperature distribution in the rectifying section, timely adjusts the heat source entering the tower and ensures the naphthalene oil collecting quality.

Preferably, twenty layers of vertical sieve tray trays are arranged in the tower body of the rectifying section.

Preferably, four side outlets of the naphthalene oil are arranged and are correspondingly connected with a fifteenth layer, a thirteenth layer, a eleventh layer and a ninth layer of vertical sieve tray from bottom to top in sequence.

Preferably, the oil-water outlet and the crude benzene reflux port are respectively connected to two sides of the tray on the uppermost layer, and the oil return port is connected with the tray on the second layer.

Preferably, ten layers of stainless steel perforated plate corrugated fillers are arranged in the tower body of the stripping section.

Preferably, a tower top manhole and a rectifying section manhole are respectively arranged on the tower walls at the top and the middle part of the rectifying section, a stripping section manhole is arranged on the tower wall at the top of the stripping section, and a tower bottom manhole is arranged on the tower wall at the top of the tower kettle. Manholes are arranged at each part in the tower, so that the top and the middle of the rectifying section and the top and the bottom of the stripping section can be cleaned conveniently, and tar hardened in the tower body can be removed in time.

Drawings

FIG. 1 is a schematic structural diagram of a novel debenzolization tower for coking and chemical production.

As shown in fig. 1: 1. a tower body, 2, a rectifying section, 2-1, a vertical sieve tray, 3, a stripping section, 4, a rich oil inlet, 5, a groove distributor, 6, an oil gas inlet, 7, a superheated steam inlet, 8, a crude benzene reflux port, 9, an oil return port, 10, a lean oil outlet, 11, a benzene steam outlet, 12-1, a first naphthalene oil outlet, 12-2, a second naphthalene oil outlet, 12-3, a third naphthalene oil outlet, 12-4, a fourth naphthalene oil outlet, 13, an oil water outlet, 14, a gas phase communication hole, 15-1, an on-site liquid level meter upper interface, 15-2, an on-site liquid level meter lower interface, 16-1, a liquid level meter upper interface, 16-2, an instrument liquid level meter lower interface, 17-1, a tower top interface, 17-2, a tower bottom interface, 18-1 and a tower top thermometer interface, 18-2 parts of a middle tower thermometer interface, 18-3 parts of a tower bottom thermometer interface, 19-1 parts of a first thermometer interface, 19-2 parts of a second thermometer interface, 19-3 parts of a third thermometer interface, 19-4 parts of a fourth thermometer interface, 20 parts of a dispersion port, 21-1 parts of a tower top manhole, 21-2 parts of a rectification section manhole, 21-3 parts of a stripping section manhole, 21-4 parts of a tower bottom manhole, 22 parts of a skirt inlet.

Detailed Description

For a better understanding of the present application, various aspects of the present application will be described in more detail with reference to the accompanying drawings. It should be understood that the detailed description is merely illustrative of exemplary embodiments of the present application and does not limit the scope of the present application in any way. Like reference numerals refer to like elements throughout the specification.

In the drawings, the thickness, size, and shape of an object have been slightly exaggerated for convenience of explanation. The figures are purely diagrammatic and not drawn to scale.

It will be further understood that the terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "including," and/or "containing," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. Further, when a statement such as "… at least one" appears after the list of listed features, the entire listed feature is modified rather than modifying individual elements in the list.

As shown in figure 1, the novel debenzolization tower for coking chemical products comprises a tower body 1, wherein the tower body 1 is formed by connecting a rectifying section 2 at the upper part and a stripping section 3 at the lower part, a sealing cover is arranged at the top of the rectifying

section

2, 20 layers of vertical sieve plate trays 2-1 are arranged in the tower body of the rectifying section 2 from top to bottom, 10 layers of stainless steel perforated plate corrugated fillers are arranged in the tower body of the stripping section 3, the fillers are supported by stainless steel arches, a tower kettle is arranged at the bottom of the stripping section 3 and is arranged on a skirt, and a skirt inlet 22 is arranged on the skirt. A rich oil inlet 4 is arranged on the tower body side wall at the connecting part of the rectifying section 2 and the stripping section 3, a groove type distributor 5 is arranged in the tower body below the rich oil inlet 4, an oil gas inlet 6 and an overheated steam inlet 7 are arranged on the tower body side wall below the stainless steel pore plate corrugated packing in the stripping section 3 from top to bottom, a lean oil outlet 10 is arranged at the bottom of the tower kettle, a tower bottom manhole 21-4 is arranged on the tower wall at the top of the tower kettle, a field liquid level meter lower interface 15-2 and an instrument liquid level meter lower interface 16-2 are arranged on the tower wall corresponding to the tower bottom manhole 21-4, a field liquid level meter upper interface 15-1 and an instrument liquid level meter upper interface 16-1 are arranged on the tower wall corresponding to the rich oil inlet 4, a tower bottom pressure meter interface 17-2 is arranged on the tower wall corresponding to the overheated steam inlet 7, a tower bottom thermometer interface 18-3 is arranged on the tower wall below the, a stripping section manhole 21-3 is also arranged on the tower wall at the top of the stripping section 3. A side outlet of naphthalene oil is arranged on the tower wall in the middle of the rectifying section 2, the side outlet corresponds to a tray with a vertical sieve plate on the 15 th layer, the 13 th layer, the 11 th layer and the 9 th layer from top to bottom respectively, a first naphthalene oil outlet 12-1, a second naphthalene oil outlet 12-2, a third naphthalene oil outlet 12-3 and a fourth naphthalene oil outlet 12-4 are sequentially arranged at the positions corresponding to the naphthalene oil outlets, and a thermometer interface 18-2 in the middle of the tower, a first thermometer interface 19-1, a second thermometer interface 19-2 and a third thermometer interface 19-3 are respectively arranged at the positions corresponding to the naphthalene oil outlets. A fourth thermometer interface 19-4 is arranged on the tower wall corresponding to the 9 th vertical sieve plate tower tray, an oil return port 9, an oil-water outlet 13 and a crude benzene return port 8 are sequentially arranged on the tower walls corresponding to the 3 rd, the 2 nd and the 1 st vertical sieve plate tower trays respectively, a gas phase communication hole 14 is also arranged on the tower wall above the oil-water outlet 13, and a rectifying section manhole 21-2 and a tower top manhole 21-1 are respectively arranged on the tower walls at the middle part and the top part of the rectifying section 2. The sealing cover is provided with a benzene steam outlet 11, a tower top pressure interface 17-1, a tower top temperature interface 18-1 and a diffusing port 20. In other embodiments, a designed number of trays or packing may be provided in both stripping section 3 and rectifying section 2, and is not limited to the configuration in this embodiment. The corrugated packing in stripping section 3 can also be formed by connecting horizontal corrugated packing and vertical corrugated packing.

The novel debenzolization tower for coking chemical products is used for carrying out rich oil debenzolization, and the specific process comprises the following steps:

the benzene steam outlet 11 is connected with a vacuum pump, after the vacuum pump is started, the non-condensable gas in the tower is discharged to a coal gas negative pressure system, so that the pressure in the debenzolization tower is controlled to be-60 to 15KPa (absolute pressure) at the tower top and-45 to 45KPa (absolute pressure) at the tower bottom, and a pressure gauge is respectively connected with a pressure gauge at a pressure gauge interface 17-1 at the tower top and a pressure gauge interface 17-2 at the tower bottom to accurately measure the pressure value; introducing high-temperature steam into the debenzolization tower from a superheated steam inlet 7, controlling the temperature in the debenzolization tower to be 65-93 ℃ at the top of the tower, controlling the temperature at the bottom of the tower to be 175-220 ℃, and respectively connecting thermometers to a thermometer interface 18-1 at the top of the tower and a thermometer interface 18-3 at the bottom of the tower to accurately measure the temperature values; rich oil is preheated to 175-; the gas phase mixture is contacted with a vertical sieve plate tray 2-1 in the rectifying section 2 layer by layer in the ascending process, the temperature is continuously reduced, the naphthalene oil is gradually separated out from the gasified benzene hydrocarbon and flows out from a side outlet of the naphthalene oil, the naphthalene oil content collected from a first naphthalene oil outlet 12-1, a second naphthalene oil outlet 12-2, a third naphthalene oil outlet 12-3 and a fourth naphthalene oil outlet 12-4 is gradually reduced according to the difference of the separation temperature, and a thermometer interface 18-2, a first thermometer interface 19-1, a second thermometer interface 19-2 and a third thermometer interface 19-3 in the middle of the tower can monitor the separation temperature of the naphthalene oil; after the rest gas phase mixture completely passes through the top layer of the vertical sieve plate tray 2-1, a part of the rest gas phase mixture is condensed into an oil-water mixture and flows out from an oil-water outlet 13, and the rest non-condensed steam is discharged from a benzene steam outlet 11 through a vacuum pump; the main component discharged from the benzene steam outlet 11 is crude benzene steam, and after the crude benzene steam is condensed and subjected to oil-water separation, the obtained crude benzene is sent back to the rectification section 2 through the crude benzene reflux port 8 for secondary resolution and rectification; the liquid phase mixture flowing out from the oil-water outlet 13 is sent back to the rectifying section 2 through the oil return port 9 after oil-water separation, and is subjected to resolution rectification again. The hot lean oil flowing out of the lean oil outlet 10 is divided into two parts according to a certain designed quantity, one part of the hot lean oil is used as a heat source and enters the debenzolization tower again from the oil gas inlet 6, and the other part of the hot lean oil enters the regenerator for regeneration. When the debenzolization tower is produced at normal pressure, the operation of the vacuum pump is stopped, the diffusing port 20 is opened, and the non-condensable gas in the tower is discharged to the coal gas negative pressure system through the diffusing port 20.

In the novel debenzolization tower for coking and chemical production, the gas-phase communication hole 14 arranged above the oil-water outlet 13 can ensure that an oil-water mixture and naphthalene oil smoothly flow out from the oil-water outlet 13 and each naphthalene oil outlet respectively; a tower top manhole 21-1, a rectifying section manhole 21-2, a stripping section manhole 21-3 and a tower bottom manhole 21-4 are respectively used for cleaning the top and middle of the rectifying section 2 and the top and bottom of the stripping section 3; the upper interface 15-1 of the field liquid level meter and the upper interface 16-1 of the instrument liquid level meter are used for detecting or monitoring the highest liquid level of the oil level in the stripping section 3, and the lower interface 15-2 of the field liquid level meter and the lower interface 16-2 of the instrument liquid level meter are used for detecting or monitoring the lowest liquid level of the oil level in the stripping section 3. The stainless steel pore plate corrugated packing used in the novel debenzolization tower for coking and chemical production has the advantages of regular geometric structure, regular arrangement, large porosity, provision of a gas-liquid flow path, improvement of a channeling flow avoiding phenomenon, large flux, low pressure reduction and high separation efficiency, and has good anti-blocking performance compared with other packing.

The novel debenzolization tower for coking and chemical production adopts a method of reduced pressure or negative pressure steam stripping, and is also provided with the oil gas inlet 6, so that hot lean oil flowing out from the lean oil outlet 10 is used as a heat source and enters the debenzolization tower from the oil gas inlet 6 again, the dependence on steam used as the heat source is greatly reduced, superheated steam introduced into the debenzolization tower is obviously reduced, and the amount of wastewater is reduced; an oil return port 9 is also designed, so that an oil-water mixture flowing out of the oil-water outlet 13 is subjected to oil-water separation and then enters the rectification section 2 again from the oil return port 9 for re-analytical rectification, and the recovery rate of benzene and naphthalene oil is improved; the tower body of the novel debenzolization tower for coking and chemical production is provided with a plurality of temperature monitoring ports for respectively detecting the temperature of each naphthalene oil collecting port, which is favorable for mastering the temperature distribution in the rectifying section 2, timely adjusts the heat source entering the tower and ensures the collection quality of the naphthalene oil.

Claims

1. A novel debenzolization tower for coking production comprises a tower body (1), wherein the tower body (1) is formed by connecting a rectifying section (2) at the upper part and a stripping section (3) at the lower part, a sealing cover is arranged at the top of the rectifying section (2), a tower kettle is arranged at the bottom of the stripping section (3), the tower kettle is arranged on a skirt, a plurality of layers of tower trays or fillers are arranged in the tower body of the rectifying section (2) and the stripping section (3), the novel debenzolization tower is characterized in that an oil-rich inlet (4) is arranged on the side wall of the tower body at the connecting part of the rectifying section (2) and the stripping section (3), an oil-gas inlet (6) and an overheated steam inlet (7) are arranged on the side wall of the tower body at the lower part of the stripping section (3), an oil-poor-outlet (10) is arranged at the bottom of the tower, a tower bottom pressure gauge interface (17-2) and a tower bottom, a liquid level meter upper interface and a liquid level meter lower interface are also arranged below the rich oil inlet (4); a plurality of naphthalene oil side line outlets are formed in the tower wall in the middle of the rectifying section (2), each naphthalene oil side line outlet is connected with a corresponding tower disc layer or a corresponding packing layer, and a thermometer interface is arranged at the position corresponding to each naphthalene oil outlet; a crude benzene reflux port (8), an oil return port (9) and an oil-water outlet (13) are arranged on the tower wall at the upper part of the rectifying section (2), a gas-phase communication hole (14) is also arranged on the tower wall above the oil-water outlet (13), the oil-water outlet (13) and the crude benzene reflux port (8) are respectively connected with the uppermost tower disc layer or the packing layer, and the oil return port (9) is connected with the tower disc layer or the packing layer below the crude benzene reflux port (8); the sealing cover is provided with a benzene steam outlet (11) and a diffusing port (20), and is also provided with a tower top pressure interface (17-1) and a tower top temperature interface (18-1).

2. The coking chemical production novel debenzolization tower as recited in claim 1, characterized in that twenty layers of vertical sieve trays are installed in the tower body of the rectification section (2).

3. The coking chemical production novel debenzolization tower as claimed in claim 2, wherein four side outlets of naphthalene oil are correspondingly connected with a fifteenth layer, a thirteenth layer, a eleventh layer and a ninth layer of vertical sieve tray from bottom to top in sequence.

4. The coking chemical production novel debenzolization tower as recited in claim 2, characterized in that the oil-water outlet (13) and the crude benzene return port (8) are respectively connected with the two sides of the tray at the uppermost layer, and the oil return port (9) is connected with the tray at the second layer.

5. The coking and chemical production novel debenzolization tower as recited in claim 1, characterized in that the tower body of the stripping section (3) is internally provided with ten layers of stainless steel perforated plate corrugated packing.

6. The novel debenzolization tower for coking production according to claim 1, characterized in that a tower top manhole (21-1) and a rectifying section manhole (21-2) are respectively arranged on the tower wall at the top and the middle of the rectifying section (2), a stripping section manhole (21-3) is arranged on the tower wall at the top of the stripping section (3), and a tower bottom manhole (21-4) is arranged on the tower wall at the top of the tower kettle.