Dividing wall tower for separating ethyl methyl carbonate and diethyl carbonate

Abstract

A dividing wall tower for separating ethyl methyl carbonate and diethyl carbonate comprises a dividing wall tower body (3), a condenser (4), a reflux tank (19), a reflux pump (7), a reboiler (15) and a tower kettle discharging pump (14). The utility model provides a dividing wall tower for separating ethyl methyl carbonate and diethyl carbonate, a light component tower and a heavy component tower of an original device are replaced, a dividing wall tower feeding hole is formed in one side of a dividing wall tower separating plate (18), a side line discharging hole is formed in the other side of the dividing wall tower separating plate (18), the energy consumption can be effectively reduced, the occupied area is saved, and the separating effect is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the production technical field of methyl ethyl carbonate and diethyl carbonate separation, especially to a kind of baffle column of methyl ethyl carbonate and diethyl carbonate separation. BACKGROUND

[0002] Methyl ethyl carbonate is a kind of asymmetric carbonate compound, compared with symmetric carbonate, it contains methyl and ethyl, has obvious structural advantage, when used as lithium battery non-aqueous electrolyte solvent, methyl ethyl carbonate is small in viscosity, large in dielectric constant, strong in solubility to lithium salt, is remarkable in promoting the energy density and discharge capacity of lithium battery.

[0003] Diethyl carbonate is low in toxicity due to its oxygen content of 40.6%, can replace hazardous methyl tert-butyl ether (MTBE), become a kind of environment-friendly oxygen-containing oil additive, not only can improve the combustion performance of fuel, but also can reduce the emission of carbon monoxide and volatile organic compounds. Diethyl carbonate can be used as lithium ion battery electrolyte, with the popularization of new energy vehicles, the demand of lithium ion battery electrolyte is rising, and the demand of diethyl carbonate is also rising.

[0004] The current mainstream method for producing methyl ethyl carbonate and diethyl carbonate is transesterification, raw material dimethyl carbonate and ethanol generate methyl ethyl carbonate and diethyl carbonate under the action of catalyst. The reacted material is evaporated to obtain a mixture of dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate, which is separated in a light component column, and dimethyl carbonate is returned to the reaction system for recycling. At the same time, methyl ethyl carbonate and diethyl carbonate crude products are separated, and then separated by a heavy component column. The two crude products are purified to obtain methyl ethyl carbonate and diethyl carbonate products. Methyl ethyl carbonate and diethyl carbonate are downstream products of dimethyl carbonate. The generated methanol in this method can be recycled as raw material for producing dimethyl carbonate. This method has milder reaction conditions, and the yield ratio of methyl ethyl carbonate and diethyl carbonate can be freely adjusted. The original process uses two rectification columns, light component column and heavy component column, to separate, which has large initial investment and large floor area. In actual production operation process, the energy consumption is high.

[0005] The baffle column has great advantage in separating multiple components. The baffle column can be equivalent to two rectification columns in the same shell. The feed inlet and side line outlet are separated by a partition plate in the column, high-purity products can be obtained in the side line, and the influence of feed on the content of side line products can be reduced. Compared with ordinary rectification column, the operation capacity of baffle column is larger, the energy saving can reach about 25%, the equipment investment can be saved by about 30%, the floor area can be saved, and the separation effect is improved. SUMMARY

[0006] The utility model wants to solve the technical problem, provide for methyl ethyl carbonate and diethyl carbonate separation partition wall tower, can reduce energy consumption, save the occupation, have extensive application prospect.

[0007] The utility model provides a kind of partition wall tower for methyl ethyl carbonate and diethyl carbonate separation, including partition wall tower (3), condenser (4), reflux tank (19), reflux pump (7), reboiler (15), tower cauldron discharge pump (14), partition wall tower (3) tower top material is connected with the inlet of condenser (4), the outlet of condenser (4) is connected with reflux tank (19), the bottom of reflux tank (19) is connected with the inlet of reflux pump (7), reflux pump (7) export material is divided into two, one is returned to the top of partition wall tower (3) as reflux, another connects light component extraction pipeline;Reboiler (15) bottom is connected with the bottom of partition wall tower (3), and the top of reboiler (15) is connected with the tower cauldron of partition wall tower (3), and the bottom of partition wall tower (3) is connected with tower cauldron discharge pump (14) inlet, and tower cauldron discharge pump (14) outlet is connected with heavy component extraction pipeline.

[0008] The partition wall tower (3) uses CY type silk screen corrugated packing, and the middle part is provided with a partition plate (18) in longitudinal direction, and the packing above the partition plate (18) is 6m, and the packing below the partition plate (18) is 6m;The feeding port is on one side of the partition plate (18), and the packing from the feeding port to the top of the partition plate (18) is 2m, and the packing from the feeding port to the bottom of the partition plate (18) is 7m;The side line discharge port is on the other side of the partition plate (18), and the packing from the side line discharge port to the top of the partition plate (18) is 6m, and the packing from the side line discharge port to the bottom of the partition plate (18) is 3m.

[0009] The partition wall tower (3) is provided with a tower top discharge flow meter (5) and a tower top discharge regulating valve (6) in the tower top discharge pipeline, and a reflux flow meter (8) and a reflux regulating valve (9) are arranged in the tower top reflux pipeline.

[0010] The feeding pipeline of the partition wall tower (3) is provided with a feeding flow meter (1) and a feeding regulating valve (2), and the side line discharge pipeline is provided with a side line discharge flow meter (10) and a side line discharge regulating valve (11), and the intermediate component extraction pipeline is connected.

[0011] The tower cauldron of the partition wall tower (3) is provided with a tower cauldron thermometer (20) and a tower cauldron liquid level meter (21), and the tower cauldron discharge pipeline is provided with a tower cauldron discharge flow meter (12) and a tower cauldron discharge regulating valve (13), and the tower cauldron liquid level meter (21), the tower cauldron discharge flow meter (12) and the tower cauldron discharge regulating valve (13) are controlled in cascade;The steam inlet pipeline of the reboiler is provided with a steam flow meter (16) and a steam regulating valve (17), and the tower cauldron thermometer (20), the steam flow meter (16) and the steam regulating valve (17) are controlled in cascade.

[0012] The partition wall column for separating methyl ethyl carbonate and diethyl carbonate provided by the application can effectively separate a mixture of dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate, continuously and efficiently provide crude methyl ethyl carbonate and crude diethyl carbonate to subsequent processes, and reduce energy consumption.

[0013] The utility model discloses a partition wall column for separating methyl ethyl carbonate and diethyl carbonate provided by the application can effectively separate a mixture of dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate, continuously and efficiently provide crude methyl ethyl carbonate and crude diethyl carbonate to subsequent processes, and reduce energy consumption.

[0014] 1, energy consumption is lower;

[0015] 2, the floor area is smaller;

[0016] 3, separation effect is better. DRAWINGS

[0017] Figure 1 It is partition wall column schematic drawing of the utility model. As shown in the figure, 1 - feed flow meter;2 - feed regulating valve;3 - partition wall column;4 - condenser;5 - overhead take-off flow meter;6 - overhead take-off regulating valve;7 - reflux pump;8 - reflux flow meter;9 - reflux regulating valve;10 - side take-off flow meter;11 - side take-off regulating valve;12 - column take-off flow meter;13 - column take-off regulating valve;14 - column take-off pump;15 - reboiler;16 - steam flow meter;17 - steam regulating valve;18 - partition plate;19 - reflux tank;20 - column bottom temperature meter;21 - column bottom level meter. DETAILED DESCRIPTION

[0018] The utility model is further described below in combination with the schematic diagram:

[0019] The mixture of dimethyl carbonate, methyl ethyl carbonate and diethyl carbonate obtained in the previous section is transported to the feed pipeline, and is transported to the partition wall column (3) through the feed flow meter (1) and the feed regulating valve (2) for rectification treatment. The dimethyl carbonate crude product is obtained at the top, is condensed in the condenser (4), and flows into the reflux tank (19) and the reflux pump (7) by gravity. After the reflux pump (7), the material is divided into two streams, one stream is taken out to the subsequent section through the overhead take-off flow meter (5) and the overhead take-off regulating valve (6), and the other stream is refluxed to the top of the partition wall column (3) through the reflux flow meter (8) and the reflux regulating valve (9).

[0020] The partition wall column (3) is three sections of packing, and the partition plate (18) is vertically arranged in the middle section of packing to separate the feed inlet and the side take-off port. The crude methyl ethyl carbonate is taken out at the side take-off port, and is transported to the subsequent section through the side take-off flow meter (10) and the side take-off regulating valve (11).

[0021] The reboiler (15) is a thermosyphon reboiler, and the material side is connected with the partitioned column (3) respectively. The heat source uses 0.5 MPa steam. The steam inlet pipeline is provided with a steam flow meter (16) and a steam regulating valve (17), and the column still temperature meter (20) arranged on the partitioned column (3) constitutes a cascade control. When the column still temperature meter (20) fluctuates, the steam flow is automatically adjusted to control the column still temperature.

[0022] The crude diethyl carbonate is concentrated in the column still of the partitioned column (3) and is taken out to the subsequent section through the column still discharge pump (14). The column still discharge pump (14) is provided with a column still discharge flow meter (12) and a column still discharge regulating valve (13) after the column still discharge pump (14), and the column still liquid level meter (21) arranged on the partitioned column (3) constitutes a cascade control. When the column still liquid level meter (21) fluctuates, the column still discharge flow is automatically adjusted to control the column still liquid level.

[0023] The packing of the partitioned column uses CY type wire mesh corrugated packing. The packing has the advantages of high spraying density, good liquid redistribution effect, large specific surface area, small gas resistance, more sufficient gas-liquid contact and larger separation effect. In the system of the dimethyl carbonate, the methyl ethyl carbonate and the diethyl carbonate mixture, the dimethyl carbonate is most easily separated from the other two substances. Since the dimethyl carbonate taken out from the top is finally returned to the reaction process for reuse, a small amount of the methyl ethyl carbonate in the dimethyl carbonate taken out from the top is appropriately allowed, so that a high rectification section is not required. Therefore, the feed inlet is arranged slightly higher than the side line take-off port, so that a longer stripping section is obtained for separating the methyl ethyl carbonate and the diethyl carbonate, and the consequence that the material is directly connected from the feed inlet to the side line take-off port due to the loose connection of the partition plate (18) and then affects the purity of the crude methyl ethyl carbonate is avoided.

[0024] The following table is a comparison before and after the device is modified:

[0025]

[0026] After the modification, the dimethyl carbonate content of the top, the methyl ethyl carbonate content of the side line and the diethyl carbonate content of the column still are all improved, and the steam consumption is reduced by 19%.

[0027] The above embodiment is only one implementation form of the present application. According to other deformations of the scheme provided by the present application, the components or steps are increased or reduced, or the present application is applied to the similar technical field of the present application, which all belong to the protection scope of the present application.

Claims

1. A partition wall column for separating methyl ethyl carbonate and diethyl carbonate, comprising a partition wall column (3), a condenser (4), a reflux tank (19), a reflux pump (7), a reboiler (15), and a bottom discharge pump (14), characterized in that... The top material of the partition wall tower (3) is connected to the inlet of the condenser (4), the outlet of the condenser (4) is connected to the reflux tank (19), the bottom of the reflux tank (19) is connected to the inlet of the reflux pump (7), and the outlet material of the reflux pump (7) is divided into two streams, one of which is returned to the top of the partition wall tower (3) as reflux, and the other is connected to the light component extraction pipeline; the partition wall tower (3) uses CY type wire mesh corrugated packing, and a partition plate (18) is set longitudinally in the middle. The packing above the partition plate (18) is 6m in total, and the packing below the partition plate (18) is 6m in total; one side of the partition plate (18) is the feed inlet, and the feed inlet is located above the feed inlet to the top of the condenser (4). The top packing of the partition plate (18) is 2m long, and the packing from the bottom of the feed inlet to the bottom of the partition plate (18) is 7m long. The other side of the partition plate (18) is the side outlet. The packing from the top of the side outlet to the top of the partition plate (18) is 6m long, and the packing from the bottom of the side outlet to the bottom of the partition plate (18) is 3m long. The bottom of the reboiler (15) is connected to the bottom of the partition wall tower (3), the top of the reboiler (15) is connected to the bottom of the partition wall tower (3), the inlet of the bottom discharge pump (14) is connected to the bottom of the partition wall tower (3), and the outlet of the bottom discharge pump (14) is connected to the heavy component extraction pipeline.

2. The indirect-wall column for separating methyl ethyl carbonate and diethyl carbonate according to claim 1, characterized in that... The top discharge pipeline is equipped with a top discharge flow meter (5) and a top discharge regulating valve (6), and the top return pipeline is equipped with a return flow meter (8) and a return regulating valve (9).

3. The indirect-wall column for separating methyl ethyl carbonate and diethyl carbonate according to claim 1, characterized in that... The feed pipeline is equipped with a feed flow meter (1) and a feed regulating valve (2), and the side discharge pipeline is equipped with a side discharge flow meter (10) and a side discharge regulating valve (11), and is connected to the intermediate component extraction pipeline.

4. The indirect-wall column for separating methyl ethyl carbonate and diethyl carbonate according to claim 1, characterized in that... The reboiler is equipped with a thermometer (20) and a level gauge (21) in the bottom of the column. The bottom discharge pipeline is equipped with a bottom discharge flow meter (12) and a bottom discharge regulating valve (13). The bottom level gauge (21), bottom discharge flow meter (12), and bottom discharge regulating valve (13) are controlled in cascade. The reboiler is equipped with a steam flow meter (16) and a steam regulating valve (17) in the steam inlet pipeline. The bottom thermometer (20), steam flow meter (16), and steam regulating valve (17) are controlled in cascade.

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