Lightweight coal tar dewaxing device

Abstract

The utility model belongs to the field of coal tar processing technology, and particularly relates to a light coal tar dewaxing device. The device comprises a feeding module, an adsorption module consisting of a first-stage fixed bed adsorption device and a second-stage fixed bed adsorption device which are connected in parallel, a recovery module and a control module, wherein the alternate operation of two-stage adsorption is realized by manually switching a control valve; during adsorption of a first-stage tower, a discharge valve is closed, and a second-stage tower can be started for supplementary adsorption; and after the adsorption is completed, switching to a desorption stage, and simultaneously switching to another tower for adsorption to realize continuous operation. A system pipeline of the device is coated with a thermal insulation material to ensure that light coal tar is kept in a gas form, a 5A molecular sieve adsorbent, N2 and other desorbents are adopted, real-time monitoring and thermal insulation measures are matched, the adsorption capacity and adsorption rate of n-alkanes can be improved, operation is easy and convenient, and design basic data are provided for industrial application.

Description

Technical Field

[0001] The utility model belongs to the field of coal tar processing technology, and in particular relates to a lightweight coal tar dewaxing device. Background Art

[0002] Light coal tar is a product produced by subjecting coal tar to thermal condensation and hydrogenation processes. During these processes, heavy components are converted to light components, thereby increasing the volatile matter content and quality of the coal tar. Light coal tar is primarily composed of C5-C11 alkanes and is a mixture of alkanes, cycloalkanes, aromatics, and olefins. At room temperature and pressure, light coal tar is a colorless, transparent liquid with a distinctive odor and a density of 0.72-0.80. It is insoluble in water but soluble in most organic solvents. Under certain processing conditions, light coal tar may contain small amounts of waxy components. These waxy components may be due to heavy components that were not completely removed during processing or may be byproducts of the process. Removing wax from lightweight coal tar improves its fluidity at low temperatures, significantly lowers its freezing point, and reduces impurity levels. Furthermore, in subsequent coal tar processing, such as hydrocracking and catalytic cracking, dewaxing can lower reaction temperatures, increase reaction rates and selectivity, thereby facilitating smooth processing and improving efficiency. Furthermore, the removed wax can be recycled, avoiding resource waste and environmental pollution.

[0003] Dewaxing units are often used to increase gasoline octane rating and yield low-pour-point coal and diesel. They also produce liquid paraffin, a crucial chemical feedstock. Liquid paraffin is primarily composed of straight-chain alkanes, particularly C16-C20 normal alkanes. The most promising and practical application of adsorption separation technology for liquid paraffin, or normal alkanes, is optimizing feedstocks for steam cracking to produce ethylene and catalytic reforming, increasing the yield of ethylene, aromatics, or gasoline per unit of naphtha, and reducing feedstock costs for steam cracking and catalytic reforming units. Removing normal alkanes through adsorption separation technology optimizes feedstock composition and improves yields of target products. Removing normal alkanes increases the proportion of crackable or reformable components in the feedstock, thereby increasing the yield of ethylene, aromatics, or gasoline per unit of naphtha production.

[0004] However, the equipment commonly used to achieve continuous adsorption separation of liquid paraffin is simulated moving bed (SMB) technology. This type of equipment has a complex structure, is difficult to maintain, and has a relatively limited scope of application and scenarios. Utility Model Content

[0005] In order to overcome the shortcomings of the above-mentioned prior art, the utility model proposes a lightweight coal tar dewaxing device, which designs a dual-tower parallel fixed bed adsorption / desorption system, increases insulation measures and introduces real-time monitoring of the adsorption rate, thereby achieving continuous operation and improving the adsorption capacity and adsorption rate of normal alkanes.

[0006] In order to achieve the above purpose, the present invention adopts the following technical solutions:

[0007] The utility model proposes a light coal tar dewaxing device, comprising a feed module, an adsorption module, a recovery module and a control valve, wherein:

[0008] The feeding module includes a raw material tank, a desorbent tank and a heating furnace, and the raw material tank and the desorbent tank are connected to the feeding port of the heating furnace through material pipelines respectively; the adsorption module includes a primary fixed bed adsorption device and a secondary fixed bed adsorption device, and the outlet of the heating furnace is divided into two routes, which are respectively connected to the feeding ports of the primary fixed bed adsorption device and the secondary fixed bed adsorption device; the discharge port of the primary fixed bed adsorption device and the discharge port of the secondary fixed bed adsorption device are connected to the total discharge port of the adsorption module, forming a parallel two-stage adsorption system; the various devices of the adsorption module are connected by material pipelines; the recovery module includes a non-adsorption product tank and a desorption product tank, and the feeding ports of the non-adsorption product tank and the desorption product tank are respectively connected to the total discharge port of the adsorption module through material pipelines; the control valve includes a pressure regulating device and a control valve arranged on the material pipeline, which are used to control the inflow and outflow of various materials.

[0009] At least one control valve is connected in series on the feed pipeline of the first-stage fixed bed adsorption device, and at least two control valves are connected in series on the discharge pipeline; at least one control valve is connected in series on the feed pipeline of the second-stage fixed bed adsorption device, and at least two control valves are connected in series on the discharge pipeline.

[0010] The adsorption module also includes an adsorption detection device, which is connected in series to the discharge pipeline of the first-stage fixed bed adsorption device and the discharge pipeline of the second-stage fixed bed adsorption device respectively.

[0011] The adsorption detection device is arranged between at least two control valves connected in series on the discharge pipeline of the first-stage fixed bed adsorption device and the discharge pipeline of the second-stage fixed bed adsorption device.

[0012] The feeding module also includes a purge gas path connected to the heating furnace feeding port.

[0013] The fixed bed adsorption separation device is pumped with purge gas through the purge gas path, and the purge gas is N2.

[0014] The pressure regulating device comprises a first feed pump and a second feed pump which are respectively connected in series on the discharge port of the raw material tank and the discharge port pipeline of the desorbent tank.

[0015] A first condenser and a second condenser are respectively connected in series before the feed inlet of the non-adsorption product tank and the feed inlet of the desorption product tank.

[0016] The raw material tank, desorbent tank, non-adsorption product tank and desorption product tank are all opened on the top.

[0017] The feed module, adsorption module and control valve pipeline are all covered with insulation materials.

[0018] The adsorbent used in the fixed bed adsorption separation device is 5A molecular sieve, and the desorbent is solvents such as N2, isooctane, and n-pentane.

[0019] When the system is working:

[0020] The raw material is initially heated by the raw material tank's own heating system, then passed through the N2 carrier gas and the raw material feed pump to the heating furnace where it is heated until it vaporizes. It then enters the first-stage fixed-bed adsorption unit for adsorption, while the control valve at the first-stage fixed-bed adsorption unit's outlet is closed. During the adsorption process, the adsorption detection device can be simultaneously activated to monitor the product and determine if adsorption is complete.

[0021] After the adsorption is completed, the discharge valve is opened, and the unadsorbed raw materials are condensed through the condenser and enter the non-adsorbed product tank for recovery.

[0022] After the entire device is purged with N2, the desorbent is transported from the desorbent tank through the feed pump to the heating furnace for heating and vaporization, and further enters the first-stage fixed bed adsorption device for desorption, and then condensed by the condenser and enters the desorption product tank, thus completing the dewaxing process.

[0023] Except for the desorbent pipeline, N2 pipeline and non-adsorbed product pipeline after condensation, the remaining pipelines of the entire device are all insulated, which can effectively improve the adsorption capacity and adsorption rate.

[0024] When the primary fixed-bed adsorption unit reaches the end of adsorption, the control valve for the feed inlet of the secondary fixed-bed adsorption unit is opened, and the control valve for the discharge outlet is closed. The raw material, heated in the heating furnace, is then fed into the secondary fixed-bed adsorption unit for supplementary adsorption. During supplementary adsorption, the control valves for the feed and discharge lines of the secondary fixed-bed adsorption unit are closed. After supplementary adsorption is complete, the control valves for the inlet and outlet lines of the primary fixed-bed adsorption unit are opened to collect the unadsorbed / adsorbed raw material. This cycle is repeated to achieve continuous operation.

[0025] Therefore, the device can carry out single-column adsorption tests and double-tower continuous operation tests to achieve the purpose of laboratory small-scale tests and industrial simulation processes.

[0026] Compared with the prior art, the present invention has the following beneficial effects:

[0027] The present utility model proposes a light coal tar dewaxing device, which constructs a dual-tower parallel fixed bed adsorption / desorption device, and performs the adsorption / desorption process separately by manual switching, which can realize overall continuous operation. The device module is flexible to build and is suitable for a variety of application scenarios. At the same time, an adsorption detection device is also provided in the system, which can monitor the adsorption state in real time, thereby achieving the purpose of improving the adsorption capacity and adsorption rate of normal alkanes. Furthermore, the present utility model increases thermal insulation measures by coating the entire system pipeline with an insulation layer, thereby ensuring that the light coal tar is always above the boiling point and maintains its gaseous form, further increasing the adsorption rate. The present device is easy to operate, can monitor the adsorption rate in real time, increase thermal insulation measures, improve adsorption capacity and adsorption rate, can be used to evaluate and study the process, explore the best process parameters, obtain product distribution, product properties and other data through sampling analysis, evaluation, and data processing, and provide basic design data for the industrial application of molecular sieve dewaxing and the construction and design of industrial equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 This is a diagram of a lightweight coal tar dewaxing device according to the present invention;

[0029] Among them: raw material tank 1; desorbent tank 2; first feed pump 3; second feed pump 4; heating furnace 5; first control valve 6, second control valve 7; first fixed bed adsorption device 8; third control valve 9; first adsorption detection device 10; fourth control valve 11; fifth control valve 12; sixth control valve 13; second fixed bed adsorption device 14; seventh control valve 15; second adsorption detection device 16; eighth control valve 17; ninth control valve 18; tenth control valve 19; first condenser 20; second condenser 21; non-adsorption product tank 22; desorption product tank 23. DETAILED DESCRIPTION

[0030] In order to help those skilled in the art better understand the present invention, the following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts should fall within the scope of protection of the present invention.

[0031] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present invention described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0032] The present invention is described in further detail below with reference to the accompanying drawings:

[0033] like Figure 1 The light coal tar dewaxing device shown includes a feed module, an adsorption module, a recovery module and a control module.

[0034] The feed module is connected to the feed port of the heating furnace 5 by the raw material tank 1, the desorbent tank 2 and the purge gas source respectively, and the material outlet pipelines of the raw material tank 1 and the desorbent tank 2 are connected in series with the first feed pump 3 and the second feed pump 4 respectively.

[0035] The adsorption module includes a first-stage fixed bed adsorption device 8 and a second-stage fixed bed adsorption device 14 connected in parallel. The outlet of the heating furnace 5 is divided into two routes, which are respectively connected to the feed ports of the first-stage fixed bed adsorption device 8 and the second-stage fixed bed adsorption device 14; the discharge port of the first-stage fixed bed adsorption device 8 and the discharge port of the second-stage fixed bed adsorption device 14 are connected to the total discharge port of the adsorption module; the pipeline in front of the feed port of the first-stage fixed bed adsorption device 8 is connected in series with two-stage control valves, namely the first control valve 6 and the second control valve 7, and the pipeline of the discharge port is connected in series with two-stage control valves, namely the third control valve 9 and the fourth control valve 11, and the third control valve 12 is connected in series with the fourth control valve 13. A first adsorption detection device 10 is also connected in series on the pipeline between the valve 9 and the fourth control valve 11; two-stage control valves are connected in series on the pipeline in front of the feed port of the secondary fixed bed adsorption device 14, namely the fifth control valve 12 and the sixth control valve 13, and two-stage control valves are connected in series on the pipeline of the discharge port, namely the seventh control valve 15 and the eighth control valve 17, and a second adsorption detection device 16 is also connected in series on the pipeline between the seventh control valve 15 and the eighth control valve 17. The two-stage fixed bed adsorption device merges into a total material outlet pipeline after the last stage, the fourth control valve 11 and the eighth control valve 17, and is connected to the recovery module.

[0036] The recovery module includes a non-adsorption product tank 22 and a desorption product tank 23. The feed ports of the non-adsorption product tank 22 and the desorption product tank 23 are respectively connected to the total discharge port of the adsorption module through material pipelines, and a first condenser 20 and a second condenser 21 are respectively connected in series on the inlet pipelines of the non-adsorption product tank 22 and the desorption product tank 23. A ninth control valve 18 and a tenth control valve 19 are respectively connected in series on the pipelines in front of the first condenser 20 and the second condenser 21 for controlling the flow of materials.

[0037] The various modules of the device proposed in this utility model are connected via material pipelines and are equipped with precision pressure gauges, pressure sensors, and safety valves. Temperature and pressure are automatically monitored by temperature and pressure sensors, respectively. Automatic temperature monitoring and control of the reaction tube core are implemented, and a secondary alarm is set, automatically returning the feed flow rate to zero and stopping feeding. Functions such as over-temperature power outage, over-pressure pump shutdown, and on-site reset are also included.

[0038] This device features a single gas feed: N2. After being depressurized by a pressure reducing valve from a gas filter, the N2 is split into two routes, serving as purge gas and nitrogen blanketing gas for the raw material tank. The depressurized N2 is then nitrogen-sealed for the raw material, which is then discharged from the top of the tank. The configuration software program programs a metering pump and electronic scale for interlocked feeding.

[0039] During operation, the device proposed in the present invention begins with the raw material, light coal tar, being initially heated by the heating system of the raw material tank 1 itself. Then, it is fed by N2 carrier gas through the first raw material feed pump 3 to the heating furnace 5, where it is heated until it is vaporized. The raw material then enters the first fixed-bed adsorption device 8 for adsorption, while the first control valve 6, second control valve 7, third control valve 9, first adsorption detection device 10, and fourth control valve 11 are closed. During the adsorption process, product monitoring can be performed by simultaneously opening the third control valve 9 and the first adsorption detection device 10 to determine whether adsorption is complete. After adsorption is complete, the valves are opened, and the unadsorbed raw material is condensed through the first condenser 20 and enters the non-adsorbed product tank 22. After the entire device is purged with N2, the desorbent is transferred from the desorbent tank 2 through the second feed pump 4 to the heating furnace 5, where it is heated until it is vaporized. The desorbent then enters the first fixed-bed adsorption device 8 for desorption, and is then condensed through the second condenser 21 before entering the desorption product tank 23, completing the dewaxing process.

[0040] The remaining material after adsorption separation exchanges heat with the refrigerant medium in the first condenser 20 before entering the non-adsorption product tank 22 for gas-liquid phase separation. The gas phase is discharged through a back-pressure valve to the dilution water wash tank and then to the tail gas pipeline. The liquid phase is discharged to the gas-liquid separation tank for sampling and analysis. The dewaxed product exchanges heat with the second condenser 21 and is cooled before entering the desorption product tank 23 for gas-liquid phase separation. The gas phase is discharged through a back-pressure valve to the water release water wash tank and then to the tail gas pipeline. The liquid phase is discharged to the gas-liquid separation tank for sampling and analysis.

[0041] Except for the desorbent pipeline, N2 pipeline, and non-adsorbed product pipeline after condensation, the remaining pipelines of the entire device are all insulated, which can effectively improve the adsorption capacity and adsorption rate.

[0042] When the first fixed-bed adsorption unit 8 reaches the final stage of adsorption, the fifth, sixth, and seventh control valves 12, 13, and 15 are opened. The second adsorption detection unit 16 and the eighth control valve 17 are closed. The heated feedstock is then passed into the second fixed-bed adsorption unit 14 for adsorption. The fifth, sixth, and seventh control valves 12, 13, and 15 are then closed. Next, the first, second, third, and fourth control valves 6, 7, 9, and 11 are opened to collect the unadsorbed and adsorbed feedstock. This cycle repeats to achieve continuous operation.

[0043] The device can conduct single-column adsorption tests and dual-tower continuous operation tests, achieving the purpose of laboratory pilot tests and industrial simulation processes. Through manual switching, the adsorption / desorption processes are carried out separately, and the overall continuous operation is mainly used to evaluate and study process flows and explore optimal process parameters. Through sampling analysis, evaluation, and data processing, data such as product distribution and product properties are obtained, providing basic design data for the industrial application of molecular sieve dewaxing and the construction and design of industrial equipment.

[0044] The above content is only for explaining the technical idea of the present invention and cannot be used to limit the protection scope of the present invention. Any changes made on the basis of the technical solution in accordance with the technical idea proposed by the present invention shall fall within the protection scope of the claims of the present invention.

Claims

1. A light coal tar dewaxing device, characterized in that: It includes a feed module, an adsorption module, a recovery module and a control module, wherein: A feed module comprises a raw material tank (1), a desorbent tank (2) and a heating furnace (5), wherein the raw material tank (1) and the desorbent tank (2) are respectively connected to the feed port of the heating furnace (5) through a material pipeline; The adsorption module comprises a first-stage fixed-bed adsorption device (8) and a second-stage fixed-bed adsorption device (14) equipped with an adsorbent. The outlet of the heating furnace (5) is divided into two paths, which are respectively connected to the feed ports of the first-stage fixed-bed adsorption device (8) and the second-stage fixed-bed adsorption device (14). The discharge port of the first-stage fixed-bed adsorption device (8) and the discharge port of the second-stage fixed-bed adsorption device (14) are connected to the main discharge port of the adsorption module to form a parallel two-stage adsorption system. The devices of the adsorption module are connected by material pipelines. The recovery module comprises a non-adsorption product tank (22) and a desorption product tank (23), wherein the feed ports of the non-adsorption product tank (22) and the desorption product tank (23) are respectively connected to the total discharge port of the adsorption module through a material pipeline; The control module includes a pressure regulating device at least arranged on the material pipeline of the feed module and an adsorption detection device and a control valve at least arranged on the adsorption module.

2. The light coal tar dewaxing device according to claim 1, characterized in that: At least one control valve is connected in series on the feed pipeline of the first-stage fixed bed adsorption device (8), and at least two control valves are connected in series on the discharge pipeline; at least one control valve is connected in series on the feed pipeline of the second-stage fixed bed adsorption device (14), and at least two control valves are connected in series on the discharge pipeline.

3. The light coal tar dewaxing device according to claim 2, characterized in that: The adsorption detection device comprises at least two groups, which are respectively connected in series to the discharge pipeline of the first-stage fixed bed adsorption device (8) and the discharge pipeline of the second-stage fixed bed adsorption device (14).

4. The light coal tar dewaxing device according to claim 3, characterized in that: The adsorption detection device is arranged between at least two control valves connected in series on the discharge pipeline of the first-stage fixed bed adsorption device (8) and the discharge pipeline of the second-stage fixed bed adsorption device (14).

5. The light coal tar dewaxing device according to claim 1, characterized in that: The feed module further comprises a purge gas path connected to the feed port of the heating furnace (5).

6. The light coal tar dewaxing device according to claim 5, characterized in that: The purge gas is pumped into the purge gas line, and the purge gas is N2.

7. The light coal tar dewaxing device according to claim 1, characterized in that: The pressure regulating device comprises a first feed pump (3) and a second feed pump (4) which are respectively connected in series to the discharge port of the raw material tank (1) and the discharge port pipeline of the desorbent tank (2).

8. The light coal tar dewaxing device according to claim 1, characterized in that: A first condenser (20) and a second condenser (21) are respectively connected in series before the feed port of the non-adsorption product tank (22) and the feed port of the desorption product tank (23).

9. The light coal tar dewaxing device according to claim 1, characterized in that: The feed module, adsorption module and control valve pipeline are coated with thermal insulation materials.

10. The light coal tar dewaxing device according to claim 1, characterized in that: The adsorbent is 5A molecular sieve, and the desorbent is N2, isooctane or n-pentane.

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