Efficient extraction tower

Abstract

The utility model relates to the field of extraction towers, in particular to an efficient extraction tower. Comprising an extractive distillation tower, a solvent recovery tower, an extractive distillation tower kettle liquid pump, an extractive distillation tower feeding heat exchanger, an extractive distillation tower condenser, an extractive distillation tower reflux tank, an extractive distillation tower reflux pump, an extractive distillation tower intermediate reboiler, a solvent recovery tower kettle liquid pump, a solvent regeneration tank, a regenerated solvent preheater, a lean solvent cooler and a lean solvent filter, the device comprises a solvent recovery tower reboiler, an extractive distillation tower reboiler, a solvent recovery tower condenser, a solvent recovery tower reflux tank, a solvent recovery tower reflux pump and a carclazyte tank feeding pump. Rich solvent at the bottom of the extractive distillation tower is fed into the solvent recovery tower, aromatic hydrocarbon and lean solvent are separated through vacuum distillation, the aromatic hydrocarbon is extracted from the top of the tower, high-purity benzene and methylbenzene are separated through the benzene tower, and the lean solvent at the bottom of the tower is fed to the upper part of the extractive distillation tower for recycling, so that the stability of the process is improved, and the efficient extraction tower work is realized.

Description

Technical Field

[0001] The utility model relates to the field of extraction towers, in particular to a high-efficiency extraction tower. Background Art

[0002] The sulfolane extractive distillation process is an extractive distillation process that uses sulfolane as a selective solvent. This process can be used to extract high-purity aromatic hydrocarbons from mixed hydrocarbons, such as hydrogenated oil, pyrolysis gasoline or reformed oil. The hydrogenated oil BT is sent to the extractive distillation tower, and non-aromatic hydrocarbons are directly separated by extractive distillation under the action of sulfolane. The rich solvent at the bottom of the extractive distillation tower is sent to the solvent recovery tower, and the aromatic hydrocarbons are separated from the lean solvent by vacuum distillation. The aromatic hydrocarbons are extracted from the top of the tower and separated into high-purity benzene and toluene through the benzene tower. The lean solvent at the bottom of the tower is sent to the upper part of the extractive distillation tower for recycling.

[0003] As the processing load increases, the frequency of fluctuations in the extraction tower increases. At the process level, corresponding adjustments are made mainly to the flooding of the extraction tower. Through the adjustments, the operation of the extraction tower is basically stable but fluctuations still occur. Affected by the flooding fluctuations, the non-aromatic benzene content remains high. If the solvent circulation volume is slightly increased, the extraction tower will show signs of flooding, and the process stability is difficult to guarantee.

[0004] Therefore, those skilled in the art provide a high-efficiency extraction tower to solve the problems raised in the above background technology. Utility Model Content

[0005] In order to solve the above technical problems, the utility model provides a high-efficiency extraction tower.

[0006] The invention comprises an extractive distillation tower, a solvent recovery tower, an extractive distillation tower condenser and an extractive distillation tower reflux tank. The outer side of the extractive distillation tower is connected with an extractive distillation tower kettle liquid pump and an extractive distillation tower feed heat exchanger. A rich solvent pipe is connected between the extractive distillation tower kettle liquid pump and the solvent recovery tower. An extractive distillation tower feed 2 is connected between the extractive distillation tower and the extractive distillation tower feed heat exchanger. An extractive distillation tower feed pipe 1 is connected to one side of the extractive distillation tower feed heat exchanger. An extractive distillation tower condenser feed pipe is connected between the extractive distillation tower and the extractive distillation tower condenser. An extractive distillation tower condenser discharge pipe is connected between the extractive distillation tower condenser and the extractive distillation tower reflux tank. An extractive distillation tower reflux pump and a water pipe 1 are connected to the outer side of the extractive distillation tower reflux tank. An extractive distillation tower reflux pipe is connected between the extractive distillation tower reflux pump and the extractive distillation tower.

[0007] Preferably, an intermediate reboiler of the extractive distillation tower is connected to the outside of the extractive distillation tower, a loop is formed between the intermediate reboiler of the extractive distillation tower and the extractive distillation tower, and a solvent recovery tower bottom liquid pump is connected to the outside of the solvent recovery tower, and a lean solvent pipe 1 is connected between the solvent recovery tower bottom liquid pump and the intermediate reboiler of the extractive distillation tower.

[0008] Preferably, a solvent regeneration tank is connected to the outer side of the lean solvent pipe 1 via a regeneration solvent pipe, and a regeneration solvent steam pipe is connected between the solvent regeneration tank and the solvent recovery tower.

[0009] Preferably, the high-efficiency extraction tower also includes a regenerated solvent preheater, a water pipe four is connected between the regenerated solvent preheater and the solvent regeneration tank, the regenerated solvent preheater is connected to a lean solvent cooler via a lean solvent pipe four, the lean solvent cooler is connected to a lean solvent filter via a lean solvent pipe five, and a lean solvent pipe is connected between the lean solvent filter and the extraction distillation tower.

[0010] Preferably, a solvent recovery tower reboiler is connected to the outside of the solvent recovery tower, a loop is formed between the solvent recovery tower and the solvent recovery tower reboiler, and an extractive distillation tower reboiler is connected to the outside of the extractive distillation tower, a reflux is formed between the extractive distillation tower reboiler and the extractive distillation tower.

[0011] Preferably, the high-efficiency extraction tower also includes a solvent recovery tower condenser and a solvent recovery tower reflux tank, a recovery tower condenser feed pipe is connected between the solvent recovery tower condenser and the solvent recovery tower, a recovery tower condenser discharge pipe is connected between the solvent recovery tower reflux tank and the solvent recovery tower condenser, and a solvent recovery tower reflux pump and a kaolin tank feed pump are connected to the outer side of the solvent recovery tower reflux tank, a recovery tower reflux pipe is connected between the solvent recovery tower reflux pump and the solvent recovery tower, and a BT distillation pipe one and a BT distillation pipe two are connected to one side of the kaolin tank feed pump.

[0012] Preferably, a solvent recovery tower vacuum aftercooler is connected to the outer side of the solvent recovery tower reflux tank, a recovery tower aftercooler feed pipe and a recovery tower aftercooler condensate pipe are connected between the solvent recovery tower vacuum aftercooler and the solvent recovery tower reflux tank, and a solvent recovery tower vacuum unit is connected to the outer side of the solvent recovery tower reflux tank, and a recovery tower non-condensable gas pipe is connected between the solvent recovery tower vacuum unit and the solvent recovery tower vacuum aftercooler.

[0013] Preferably, the outside of the solvent recovery tower reflux tank is connected to a co-solvent tank via a second water pipe, one side of the co-solvent tank is connected to a co-solvent pump, and the outside of the co-solvent pump is connected to a third water pipe.

[0014] Preferably, the outer side of the extractive distillation tower feed heat exchanger is connected with a second lean solvent pipe and a third lean solvent pipe, and the outer side of the extraction tower reflux pipe is connected with a non-aromatic hydrocarbon pipe.

[0015] Preferably, the extractive distillation tower is provided with 70 floating valve trays in total, the upper 8 trays are mainly used to recover a small amount of solvent in the vapor evaporated from the top of the extraction tower, and the 62nd tray is a sensitive tray, and the aromatics after removal of non-aromatics are separated from the lean solvent in the recovery tower.

[0016] Technical effects and advantages of the utility model:

[0017] The utility model sends the rich solvent at the bottom of the extractive distillation tower to a solvent recovery tower, separates aromatic hydrocarbons from lean solvents through vacuum distillation, extracts aromatic hydrocarbons from the top of the tower, separates high-purity benzene and toluene through a benzene tower, and the lean solvent at the bottom of the tower is sent to the upper part of the extractive distillation tower for recycling, thereby improving the stability of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a high-efficiency extraction tower provided in an embodiment of the present application;

[0019] In the figure:

[0020] C-1201, extractive distillation tower, C-1202, solvent recovery tower, P-1202A / B, extractive distillation tower bottom liquid pump, E-1201, extractive distillation tower feed heat exchanger, E-1204, extractive distillation tower condenser, V-1201, extractive distillation tower reflux tank, P-1201A / B, extractive distillation tower reflux pump, E-1202, extractive distillation tower intermediate reboiler, P-1203A / B, solvent recovery tower bottom liquid pump, V-1202, solvent regeneration tank, E-1220, regenerated solvent preheater, E-1209, lean solvent cooler, F I-1201, lean solvent filter, E-1205, solvent recovery tower reboiler, E-1203, extraction distillation tower reboiler, E-1206, solvent recovery tower condenser, V-1203, solvent recovery tower reflux tank, P-1204A / B, solvent recovery tower reflux pump, P-1206A / B, kaolin tank feed pump, E-1207, solvent recovery tower vacuum aftercooler, X-1201, solvent recovery tower vacuum unit, V-1205, co-solvent tank, P-1205A / B, co-solvent pump, 146, extraction tower feed pipe 1, 148, extraction tower feed 2, 149, lean solvent pipe, 150, extraction tower condenser feed pipe, 151, extraction tower condenser discharge pipe, 152. Extraction tower reflux pipe, 153. Non-aromatic hydrocarbon pipe, 154. Water pipe one, 155. Rich solvent pipe, 156. Recovery tower condenser feed pipe, 157. Recovery tower condenser discharge pipe, 158. Recovery tower aftercooler feed pipe, 159. Recovery tower aftercooler condensate pipe, 160. Recovery tower non-condensable gas pipe, 161. Recovery tower reflux pipe, 162. BT fraction pipe one, 162-1. BT fraction pipe two, 163. Water pipe two, 164. Regeneration solvent pipe, 165. Water pipe three, 166. Water pipe four, 167. Regeneration solvent steam pipe, 168. Lean solvent pipe one, 169. Lean solvent pipe two, 170. Lean solvent pipe three, 171. Lean solvent pipe four, 172. Lean solvent pipe five. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments. The embodiments of the present invention are provided for the purpose of illustration and description, and are not intended to be exhaustive or to limit the present invention to the disclosed forms. Many modifications and variations are obvious to those of ordinary skill in the art. The embodiments are selected and described in order to better illustrate the principles and practical applications of the present invention, and to enable those of ordinary skill in the art to understand the present invention and thereby design various embodiments with various modifications suitable for specific purposes.

[0022] Example 1

[0023] See also Figure 1 In this embodiment, a high-efficiency extraction tower is provided.

[0024] It includes an extractive distillation tower C-1201 and a solvent recovery tower C-1202, the outer side of the extractive distillation tower C-1201 is connected with an extractive distillation tower bottom liquid pump P-1202A / B and an extractive distillation tower feed heat exchanger E-1201, a rich solvent pipe 155 is connected between the extractive distillation tower bottom liquid pump P-1202A / B and the solvent recovery tower C-1202, an extractive tower feed second 148 is connected between the extractive distillation tower C-1201 and the extractive distillation tower feed heat exchanger E-1201, and one side of the extractive distillation tower feed heat exchanger E-1201 is connected with an extractive tower feed pipe one 146;

[0025] It also includes an extractive distillation tower condenser E-1204 and an extractive distillation tower reflux tank V-1201, wherein an extractive distillation tower condenser feed pipe 150 is connected between the extractive distillation tower C-1201 and the extractive distillation tower condenser E-1204, an extractive distillation tower condenser discharge pipe 151 is connected between the extractive distillation tower condenser E-1204 and the extractive distillation tower reflux tank V-1201, an extractive distillation tower reflux pump P-1201A / B and a water pipe 154 are connected to the outer side of the extractive distillation tower reflux tank V-1201, and an extractive distillation tower reflux pipe 152 is connected between the extractive distillation tower reflux pump P-1201A / B and the extractive distillation tower C-1201;

[0026] The outer side of the extractive distillation tower C-1201 is connected with an intermediate reboiler E-1202 of the extractive distillation tower, a loop is formed between the intermediate reboiler E-1202 of the extractive distillation tower and the extractive distillation tower C-1201, and the outer side of the solvent recovery tower C-1202 is connected with a solvent recovery tower bottom liquid pump P-1203A / B, a lean solvent pipe 168 is connected between the solvent recovery tower bottom liquid pump P-1203A / B and the intermediate reboiler E-1202 of the extractive distillation tower, and the outer side of the lean solvent pipe 168 is connected with a solvent regeneration tank V-1202, a regeneration solvent pipe 164 is connected between the solvent regeneration tank V-1202 and the lean solvent pipe 168, and a regeneration solvent steam pipe 167 is connected between the solvent regeneration tank V-1202 and the solvent recovery tower C-1202.

[0027] The present scheme also includes a regenerated solvent preheater E-1220, a water pipe four 166 is connected between the regenerated solvent preheater E-1220 and the solvent regeneration tank V-1202, a lean solvent cooler E-1209 is connected to the outer side of the regenerated solvent preheater E-1220, a lean solvent pipe four 171 is connected between the lean solvent cooler E-1209 and the regenerated solvent preheater E-1220, a lean solvent filter FI-1201 is connected to the outer side of the lean solvent cooler E-1209, a lean solvent pipe five 172 is connected between the lean solvent filter FI-1201 and the lean solvent cooler E-1209, and a lean solvent pipe 149 is connected between the lean solvent filter FI-1201 and the extractive distillation tower C-1201.

[0028] The outer side of the solvent recovery tower C-1202 is connected to a solvent recovery tower reboiler E-1205, and a loop is formed between the solvent recovery tower C-1202 and the solvent recovery tower reboiler E-1205. The outer side of the extractive distillation tower C-1201 is connected to an extractive distillation tower reboiler E-1203, and a reflux is formed between the extractive distillation tower reboiler E-1203 and the extractive distillation tower C-1201.

[0029] The high-efficiency extraction tower also includes a solvent recovery tower condenser E-1206 and a solvent recovery tower reflux tank V-1203. A recovery tower condenser feed pipe 156 is connected between the solvent recovery tower condenser E-1206 and the solvent recovery tower C-1202. A recovery tower condenser discharge pipe 157 is connected between the solvent recovery tower reflux tank V-1203 and the solvent recovery tower condenser E-1206.

[0030] The outer side of the solvent recovery tower reflux tank V-1203 is connected with a solvent recovery tower reflux pump P-1204A / B and a kaolin tank feed pump P-1206A / B, a recovery tower reflux pipe 161 is connected between the solvent recovery tower reflux pump P-1204A / B and the solvent recovery tower C-1202, and one side of the kaolin tank feed pump P-1206A / B is connected with a BT distillation pipe 162 and a BT distillation pipe 2 162-1. When kaolin tank adsorption is required, the kaolin tank feed pump P-1206A / B is connected to the BT distillation pipe 162, and when kaolin tank adsorption is not required, the kaolin tank feed pump P-1206A / B is connected to the BT distillation pipe 2 162-1.

[0031] The outer side of the solvent recovery tower reflux tank V-1203 is connected with a solvent recovery tower vacuum aftercooler E-1207, and a recovery tower aftercooler feed pipe 158 and a recovery tower aftercooler condensate pipe 159 are connected between the solvent recovery tower vacuum aftercooler E-1207 and the solvent recovery tower reflux tank V-1203. The outer side of the solvent recovery tower reflux tank V-1203 is connected with a solvent recovery tower vacuum unit X-1201, and a recovery tower non-condensable gas pipe 160 is connected between the solvent recovery tower vacuum unit X-1201 and the solvent recovery tower vacuum aftercooler E-1207.

[0032] The outer side of the solvent recovery tower reflux tank V-1203 is connected to a co-solvent tank V-1205, and the co-solvent tank V-1205 and the solvent recovery tower reflux tank V-1203 are connected through a water pipe 2 163. One side of the co-solvent tank V-1205 is connected to a co-solvent pump P-1205A / B, and the outer side of the co-solvent pump P-1205A / B is connected to a water pipe 3 165.

[0033] The outer side of the extractive distillation tower feed heat exchanger E-1201 is connected with a lean solvent pipe 2 169 and a lean solvent pipe 3 170, and the outer side of the extraction tower reflux pipe 152 is connected with a non-aromatic hydrocarbon pipe 153.

[0034] The present solution also includes multiple groups of valves required during actual use.

[0035] When the utility model is used, the scheme realizes the separation of aromatic hydrocarbons and non-aromatic hydrocarbons. By adding sulfolane to the BT fraction, the vapor pressure of each component in the raw material changes, so that non-aromatic hydrocarbons such as paraffins and cycloalkanes are separated from aromatic hydrocarbons, and a rich solvent containing high-purity aromatic hydrocarbons is obtained at the bottom of the tower. The upper section of the tower (above the solvent feed port) is the solvent recovery section, the middle section of the tower is the extraction distillation section, and the lower section is the aromatic hydrocarbon concentration section;

[0036] The raw material passing through the extractive distillation tower enters the intermediate reboiler E-1202 of the extractive distillation tower through the extractive tower feed pipe 146 to exchange heat with the lean solvent at a heat exchange temperature of 95°C. After the heat exchange, it is sent to the middle of the extractive distillation tower C-1201 through flow control;

[0037] The lean solvent from the solvent recovery tower recovers heat through the regeneration solvent preheater E-1220 and enters the lean solvent water cooler E-1209. The lean solvent temperature is adjusted to 115-125°C by controlling the bypass of the heat exchanger. The lean solvent passes through the lean solvent filter FI-1201 to remove mechanical impurities and then enters the extractive distillation tower C-1201 from the 9th tray. The lean solvent flow rate is adjusted to maintain the solvent / feed ratio of about 5.1 to 7.1. Under the selective action of sulfolane, the separation of aromatics and non-aromatics is achieved.

[0038] The gas evaporated from the top of the extractive distillation tower C-1201 includes all non-aromatic hydrocarbons, a small amount of aromatic hydrocarbons and a trace amount of solvent sulfolane. The solvent is recovered in the upper solvent recovery section of the tower. The non-aromatic hydrocarbons are condensed by the extraction tower condenser (E-1204), and the condensate enters the extraction tower reflux tank V-1201. A small amount of water (40°C) is separated in the reflux tank water separator and flows to the co-solvent tank V-1205 by gravity. After being heated (116°C) by the regeneration solvent preheater E-1220 through the co-solvent pump P1205A / B, it enters the solvent regeneration tank V-1202 as a recovery tower to remove steam;

[0039] Part of the non-aromatic hydrocarbons are refluxed to the extraction distillation tower through the extraction tower reflux pump P-1201A / B, and part of them are sent to the tank farm as by-products;

[0040] The bottom products of the extractive distillation tower C-1201 mainly include sulfolane and aromatics, which become rich solvents and are sent to the middle of the solvent recovery tower C-1202 for stripping after flow control by the rich solvent pump P-1202A / B. The top pressure of the extractive distillation tower C-1201 is achieved through the split-range control of the air venting control valve and the nitrogen supplement control valve of the extraction tower reflux tank. The heat source of the extraction tower reboiler E-1203 adopts circulating heat transfer oil.

[0041] Since the feed is C5-C8 fraction, the boiling point range is very wide. An intermediate reboiler (E-1202) is designed in the middle of the extractive distillation tower to enhance the effect of removing heavy non-aromatic hydrocarbons in the extractive distillation tower C-1201. This reboiler can also avoid the formation of gas-liquid-liquid three-phase in the upper part of the extractive distillation tower, and the heat source uses the hot lean oil at the bottom of the solvent recovery tower C-1202.

[0042] The pH value of the lean solvent is controlled by injecting monoethanolamine into the system, and a toluene solution containing 5% defoamer is injected into the lean solvent to avoid foaming in the extractive distillation column. The amount of defoamer is controlled at 1-3 mg / kg lean solvent. The operating objectives of the extractive distillation column are as follows:

[0043] Ensure that the aromatic hydrocarbons enriched in sulfolane at the bottom of the tower do not contain non-aromatic hydrocarbons (benzene + toluene ≥ 99.95%); ensure that the content of aromatic hydrocarbons and solvents in the vapor at the top of the tower is as low as possible.

[0044] The extractive distillation tower is equipped with 70 floating valve trays, of which the top 8 trays are mainly used to recover a small amount of solvent in the vapor evaporated from the top of the extraction tower. The 62nd tray is a sensitive tray. Aromatics after removal of non-aromatics are separated from the lean solvent in the recovery tower (C-1202).

[0045] Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field and related fields without creative work should fall within the scope of protection of the present invention. Structures, devices and operating methods not specifically described and explained in the present invention shall be implemented according to conventional means in the field unless otherwise specified and limited.

Claims

1. A high-efficiency extraction tower, characterized in that: It comprises an extractive distillation tower (C-1201) and a solvent recovery tower (C-1202), wherein the outer side of the extractive distillation tower (C-1201) is connected with an extractive distillation tower bottom liquid pump (P-1202A / B) and an extractive distillation tower feed heat exchanger (E-1201), a rich solvent pipe (155) is connected between the extractive distillation tower bottom liquid pump (P-1202A / B) and the solvent recovery tower (C-1202), an extractive tower feed second (148) is connected between the extractive distillation tower (C-1201) and the extractive distillation tower feed heat exchanger (E-1201), and one side of the extractive distillation tower feed heat exchanger (E-1201) is connected with an extractive tower feed pipe one (146); It also includes an extractive distillation tower condenser (E-1204) and an extractive distillation tower reflux tank (V-1201), wherein an extractive distillation tower condenser feed pipe (150) is connected between the extractive distillation tower (C-1201) and the extractive distillation tower condenser (E-1204), an extractive distillation tower condenser discharge pipe (151) is connected between the extractive distillation tower condenser (E-1204) and the extractive distillation tower reflux tank (V-1201), an extractive distillation tower reflux pump (P-1201A / B) and a water pipe (154) are connected to the outer side of the extractive distillation tower reflux tank (V-1201), and an extractive distillation tower reflux pipe (152) is connected between the extractive distillation tower reflux pump (P-1201A / B) and the extractive distillation tower (C-1201).

2. A high-efficiency extraction tower according to claim 1, characterized in that: The outer side of the extractive distillation tower (C-1201) is connected to an intermediate reboiler (E-1202) of the extractive distillation tower, a loop is formed between the intermediate reboiler (E-1202) of the extractive distillation tower and the extractive distillation tower (C-1201), and the outer side of the solvent recovery tower (C-1202) is connected to a solvent recovery tower bottom liquid pump (P-1203A / B), and a lean solvent pipe (168) is connected between the solvent recovery tower bottom liquid pump (P-1203A / B) and the intermediate reboiler (E-1202) of the extractive distillation tower.

3. A high-efficiency extraction tower according to claim 2, characterized in that: The outer side of the lean solvent pipe (168) is connected to a solvent regeneration tank (V-1202) via a regeneration solvent pipe (164), and a regeneration solvent steam pipe (167) is connected between the solvent regeneration tank (V-1202) and the solvent recovery tower (C-1202).

4. A high-efficiency extraction tower according to claim 3, characterized in that: The high-efficiency extraction tower also includes a regenerated solvent preheater (E-1220), a water pipe four (166) is connected between the regenerated solvent preheater (E-1220) and the solvent regeneration tank (V-1202), the regenerated solvent preheater (E-1220) is connected to a lean solvent cooler (E-1209) via a lean solvent pipe four (171), the lean solvent cooler (E-1209) is connected to a lean solvent filter (FI-1201) via a lean solvent pipe five (172), and a lean solvent pipe (149) is connected between the lean solvent filter (FI-1201) and the extraction distillation tower (C-1201).

5. A high-efficiency extraction tower according to claim 4, characterized in that: The outer side of the solvent recovery tower (C-1202) is connected to a solvent recovery tower reboiler (E-1205), and a loop is formed between the solvent recovery tower (C-1202) and the solvent recovery tower reboiler (E-1205). The outer side of the extractive distillation tower (C-1201) is connected to an extractive distillation tower reboiler (E-1203), and a reflux is formed between the extractive distillation tower reboiler (E-1203) and the extractive distillation tower (C-1201).

6. A high-efficiency extraction tower according to claim 5, characterized in that: The high-efficiency extraction tower also includes a solvent recovery tower condenser (E-1206) and a solvent recovery tower reflux tank (V-1203). A recovery tower condenser feed pipe (156) is connected between the solvent recovery tower condenser (E-1206) and the solvent recovery tower (C-1202). A recovery tower condenser discharge pipe (157) is connected between the solvent recovery tower reflux tank (V-1203) and the solvent recovery tower condenser (E-1206). The outer side of the tower reflux tank (V-1203) is connected to a solvent recovery tower reflux pump (P-1204A / B) and a bleaching clay tank feed pump (P-1206A / B), a recovery tower reflux pipe (161) is connected between the solvent recovery tower reflux pump (P-1204A / B) and the solvent recovery tower (C-1202), and one side of the bleaching clay tank feed pump (P-1206A / B) is connected to BT distillation pipe one (162) and BT distillation pipe two (162-1).

7. A high-efficiency extraction tower according to claim 6, characterized in that: The outer side of the solvent recovery tower reflux tank (V-1203) is connected to a solvent recovery tower vacuum aftercooler (E-1207), a recovery tower aftercooler feed pipe (158) and a recovery tower aftercooler condensate pipe (159) are connected between the solvent recovery tower vacuum aftercooler (E-1207) and the solvent recovery tower reflux tank (V-1203), and the outer side of the solvent recovery tower reflux tank (V-1203) is connected to a solvent recovery tower vacuum unit (X-1201), and a recovery tower non-condensable gas pipe (160) is connected between the solvent recovery tower vacuum unit (X-1201) and the solvent recovery tower vacuum aftercooler (E-1207).

8. A high-efficiency extraction tower according to claim 7, characterized in that: The outside of the solvent recovery tower reflux tank (V-1203) is connected to a co-solvent tank (V-1205) via a second water pipe (163), one side of the co-solvent tank (V-1205) is connected to a co-solvent pump (P-1205A / B), and the outside of the co-solvent pump (P-1205A / B) is connected to a third water pipe (165).

9. A high-efficiency extraction tower according to claim 8, characterized in that: The outer side of the extractive distillation tower feed heat exchanger (E-1201) is connected to a lean solvent pipe 2 (169) and a lean solvent pipe 3 (170), and the outer side of the extraction tower reflux pipe (152) is connected to a non-aromatic hydrocarbon pipe (153).

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