CN113171625A - Device and method for preparing liquid carbon dioxide in low-temperature methanol washing process - Google Patents
Device and method for preparing liquid carbon dioxide in low-temperature methanol washing process Download PDFInfo
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Abstract
The invention provides a device and a method for preparing liquid carbon dioxide in a low-temperature methanol washing process, wherein the device comprises a heat exchanger E1, a heat exchanger E2 and a flash tank V1 which are sequentially arranged, a gas-phase outlet of the flash tank V1 is connected to a gas-liquid separation tank V2 through a first heat exchanger E3, and a liquid-phase outlet of the gas-liquid separation tank V2 is a liquid carbon dioxide outlet; and a liquid phase outlet of the flash tank V1 is connected to a methanol collecting system after heat exchange by taking a heat exchanger E1 as a heat exchange medium. The operation method comprises the following specific steps: s1, heating the carbon dioxide-rich methanol obtained from the low-temperature methanol washing process, and then feeding the heated carbon dioxide-rich methanol into a flash tank for thermal desorption; and S2, carrying out gas-liquid separation on the gas separated by thermal desorption after heat exchange and condensation to obtain liquid carbon dioxide. The invention heats the methanol rich in carbon dioxide to resolve high-pressure gas, and the resolved gas can be liquefied to obtain liquid carbon dioxide by freezing and liquefying. The method does not need the power consumption of gas pressure increase, and provides an economic route for the byproduct carbon dioxide of low-temperature methanol washing.
Description
Technical Field
The invention belongs to the field of gas separation, relates to the separation of carbon dioxide in gas, and more particularly relates to a device and a method for preparing liquid carbon dioxide in a low-temperature methanol washing process.
Background
Global warming is a consequence of earth climate change caused by human behavior, with the greenhouse gas carbon dioxide being one of the major causes. In recent years, natural disasters occur frequently around the world, and one of the main reasons is caused by excessive use of fossil energy by human beings and emission of carbon dioxide. In order to slow down and prevent global warming from lowering and protect the world environment, low carbon emission is more and more accepted by various countries in the world.
The carbon dioxide has high civil and industrial value on the other side of valuable resources, and has good development prospect in the fields of greenhouse gas fertilizer, vegetable and meat preservation, oil displacement in oil fields, degradable plastic production and the like.
The low-temperature methanol washing discharges a large amount of carbon dioxide while purifying the process gas, the carbon dioxide is captured in the process, carbon dioxide products are obtained, the additional output value is improved, and the enterprise benefit is improved.
Disclosure of Invention
The invention provides a device and a method for preparing liquid carbon dioxide in a low-temperature methanol washing process, which can reduce the emission of carbon dioxide, produce carbon dioxide products and improve the enterprise benefit.
The device for preparing liquid carbon dioxide in the low-temperature methanol washing process comprises a heat exchanger E1, a heat exchanger E2 and a flash tank V1 which are sequentially arranged, wherein a gas-phase outlet of the flash tank V1 is connected to a gas-liquid separation tank V2 through a first heat exchanger E3, and a liquid-phase outlet of the gas-liquid separation tank V2 is a liquid carbon dioxide outlet; and a liquid phase outlet of the flash tank V1 is connected to a methanol collecting system after heat exchange by taking a heat exchanger E1 as a heat exchange medium.
Further, a pressure control valve PV1 is arranged on a pipeline between the heat exchanger E2 and the flash tank V1; a pressure control valve PV2 is arranged on a pipeline between the flash tank V1 and the gas-liquid separation tank V2.
Furthermore, a liquid level control valve LV1 is arranged on a pipeline between the liquid phase outlet of the flash tank V1 and the heat exchanger E1, and a liquid level control valve LV2 is arranged on a pipeline at the liquid phase outlet of the gas-liquid separation tank V2.
The invention also relates to a method for preparing liquid carbon dioxide in the low-temperature methanol washing process, which comprises the following steps:
s1, heating the carbon dioxide-rich methanol obtained from the low-temperature methanol washing process, and then feeding the heated carbon dioxide-rich methanol into a flash tank for thermal desorption;
and S2, carrying out gas-liquid separation on the gas separated by thermal desorption after heat exchange and condensation to obtain liquid carbon dioxide.
Further, the liquid methanol thermally desorbed from the flash tank is conveyed to a heat exchanger E1 through a pipeline to be used as a heat exchange medium of the liquid methanol, and the liquid methanol is used for preheating the methanol rich in carbon dioxide.
Further, the pressure of the carbon dioxide-rich methanol obtained from the low-temperature methanol washing process is 3-5.6 MPa.
Further, the temperature of the carbon dioxide-rich methanol is 40 ℃ or higher after heating.
Further, the pressure of the flash tank is 1.5 to 4MPa when the flash tank is subjected to thermal desorption.
Further, the pressure of the gas-liquid separation tank is controlled to be 1.1-1.3 MPa.
Further, the gas phase obtained by the gas-liquid separation contains H2And CO gas, recycling; the obtained liquid phase is a crude liquid carbon dioxide product and is sent to a downstream process for refining.
In the traditional process, the total low-temperature methanol washing is to absorb and remove carbon dioxide in the process gas by methanol under high pressure and resolve the carbon dioxide under low pressure, and the resolved gas carbon dioxide has relatively low pressure. If the carbon dioxide product needs to be prepared, the pressure of the low-pressure carbon dioxide resolved by the methanol needs to be increased, and the low-pressure carbon dioxide is frozen and liquefied, so that the corresponding power for increasing the pressure is consumed in the process.
The invention heats and analyzes the methanol absorbing the carbon dioxide under high pressure, and the analyzed high-pressure gas can be frozen and liquefied to obtain a liquid carbon dioxide product, thereby saving the power consumption for improving the pressure. Not only can high-efficiently retrieve carbon dioxide, the output carbon dioxide product promotes the performance of enterprises, can also reduce carbon dioxide and discharge. Provides an economic route for the byproduct carbon dioxide in the low-temperature methanol washing process.
Drawings
FIG. 1 is a diagram of the device structure and process flow provided by the present invention.
Detailed Description
Embodiments of the present invention will be described in detail below with reference to examples, but those skilled in the art will appreciate that the following examples are only illustrative of the present invention and should not be construed as limiting the scope of the present invention.
As shown in fig. 1, in the low-temperature methanol washing process, carbon dioxide-rich methanol at the outlet of the carbon washing tower, which absorbs carbon dioxide, is heated and heated by heat exchangers E1 and E2, hot carbon dioxide-rich methanol enters a flash tank V1 for desorption, the desorption pressure of the hot carbon dioxide-rich methanol is controlled by a pressure control valve PV1, and methanol output from the bottom of the flash tank V1 is subjected to heat exchange by a heat exchanger E1 and is sent to a downstream regeneration process; the analysis gas output from the top of the flash tank V1 is frozen through a heat exchanger E3, the frozen analysis gas is subjected to pressure reduction under the control of a pressure control valve PV2 and enters a gas-liquid separation tank V2 for gas-liquid separation, and the gas containing H2 and CO output from the top of the gas-liquid separation tank V2 is recycled; liquid carbon dioxide output from the bottom of the gas-liquid separation tank V2 is sent to downstream refining processes to prepare carbon dioxide products meeting the requirements.
And (4) completing high-pressure thermal desorption of the carbon dioxide-rich methanol, and preparing liquid carbon dioxide by freezing, liquefying and separating the desorption gas.
a. In the low-temperature methanol washing process, carbon dioxide-rich methanol (01) which absorbs carbon dioxide and is at the outlet of a carbon washing tower is preheated by a heat exchanger (E1) and heated by a heat exchanger (E2);
b. the hot carbon dioxide-rich methanol (03) is decompressed by a pressure control valve PV1 and then enters a flash tank (V1) for desorption, and the pressure of the desorption gas is regulated by a control valve PV 1;
c. the amount of methanol (05) output from the bottom of the flash tank (V1) is regulated by a control valve LV1 so as to control the liquid level of the flash tank (V1);
d. the methanol (06) output by the liquid level control valve LV1 is cooled by a heat exchanger (E1), and the cooled methanol (07) is sent to a downstream regeneration process;
e. the desorption gas (08) output from the top of the flash tank (V1) is cooled by a heat exchanger (E3);
f. the pressure of an output medium (09) of the heat exchanger (E3) is regulated by a pressure control valve PV2 to enter a gas-liquid separation tank (V2), and gas-liquid separation is carried out in the gas-liquid separation tank (V2);
g. recycling the gas (11) containing H2 and CO output from the top of the gas-liquid separation tank (V2);
h. the amount of the liquid carbon dioxide (12) output from the bottom of the gas-liquid separation tank (V2) is adjusted by a control valve LV2 so as to control the liquid level of the gas-liquid separation tank (V2)
i. The crude liquid carbon dioxide (13) output by the liquid level control valve LV2 is sent to a downstream refining process to prepare the carbon dioxide which meets the requirement.
The amount of residual gas in the methanol (05) is determined by the temperature heated by the heat exchanger (E2) and the flash pressure of a flash tank (V1), and simultaneously determines the amount of desorbed gas of the carbon dioxide-rich methanol; the temperature of the gas to be analyzed after being frozen by the heat exchanger (E3) and the pressure of the gas-liquid separation tank (V2) determine the amount of the circulating gas produced by the gas to be analyzed and determine the yield of the liquid carbon dioxide. The higher the temperature of the analysis gas quantity is, the larger the analysis gas quantity is; the lower the analytic pressure is, the larger the analytic gas quantity is; freezing and condensing the desorption gas rich in the carbon dioxide methanol, wherein the freezing temperature of the desorption gas determines the yield of the carbon dioxide product, and the yield of the carbon dioxide product is higher when the temperature is lower.
Example 1
Gas purification process for low-temperature methanol washing hydrogen production with pressure grade of 3.5Mpa
3.2Mpa, -18.5 ℃ and 8500kmol/H, and the composition is H2：30.855kmol/h，CO:0.595kmol/h，CO2:1877.055kmol/h，CH36591.495kmol/h low-temperature methanol washing process, wherein carbon dioxide-rich methanol (01) which absorbs carbon dioxide and is at the outlet of a carbon washing tower is preheated by a heat exchanger (E1) and heated by a heat exchanger (E2); reducing the pressure of the heated carbon dioxide-rich methanol (03) through a pressure control valve (PV1), feeding a gas-liquid mixed medium (04) after the pressure control valve (PV1) into a flash tank (V1) for analysis, regulating the amount of methanol (05) output from the bottom of the flash tank (V1) through a liquid level control valve (LV1), controlling the liquid level of the flash tank (V1), reducing the temperature of the methanol (06) output from the liquid level control valve (LV1) through a heat exchanger (E1), and feeding the methanol (07) cooled to-14.5 ℃ to a downstream process for regeneration; the desorption gas (08) output from the top of the flash tank (V1) is frozen to-36 ℃ through a heat exchanger (E3), the-36 ℃ medium (09) output from the heat exchanger (E3) is decompressed through a pressure control valve (PV2), the decompressed gas-liquid mixed medium (10) enters a gas-liquid separation tank (V2) for gas-liquid separation after the pressure control valve (PV2), and H-containing gas output from the top of the gas-liquid separation tank (V2)2And CO gas (11) is recycled as recycle gas, the amount of liquid carbon dioxide (12) output from the bottom of the gas-liquid separation tank (V2) is adjusted by a liquid level control valve (LV2) so as to control the liquid level of the gas-liquid separation tank (V2), and crude liquid carbon dioxide (13) output from the liquid level control valve (LV2) is sent to a downstream refining process to prepare required product carbon dioxide.
The higher the temperature of the heated carbon dioxide-rich methanol (03) and the lower the pressure of the flash tank (V1), the more gas is desorbed and the higher the yield of liquid carbon dioxide (10) is obtained.
The product parameters output by the device are as follows:
working condition 1
Heating the carbon dioxide-rich methanol (03) to 65 ℃, wherein the desorption pressure of a flash tank (V1) is 3.0Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.1Mpa
01 #: -18.5 ℃, 3.2Mpa, 8500kmol/H of a liquid wherein H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
02 #: 43.96 deg.C, 3.19MPa, 8500kmol/H gas-liquid mixture, wherein H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
03 #: 65 ℃ and 3.18MPa, 8500kmol/H of a gas-liquid mixture in which H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
05 #: 64.12 deg.C, 3.00Mpa, 7452.57kmol/H liquid, wherein H2:1.50364kmol/h、CO:0.0537kmol/h、CO2:904.127kmol/h、CH3OH:6546.89kmol/h；
07 #: -14.5 ℃, 2.99MPa, 7452.57kmol/H of a liquid wherein H2:1.50364kmol/h、CO:0.0537kmol/h、CO2:904.127kmol/h、CH3OH:6546.89kmol/h；
08#: 64.12 deg.C, 3.00Mpa, 1047.43kmol/H gas, wherein H2:29.3514kmol/h、CO:0.5413kmol/h、CO2:972.929kmol/h、CH3OH:44.61kmol/h；
09 #: -36 ℃ and 2.99MPa 1047.43kmol/H of a gas-liquid mixture, wherein H2:29.3514kmol/h、CO:0.5413kmol/h、CO2:972.929kmol/h、CH3OH:44.61kmol/h；
11 #: -46.49 ℃ gas at 1.1MPa 108.699kmol/H, wherein H2:28.3496kmol/h、CO:0.45151kmol/h、CO2:79.89kmol/h、CH3OH:0.00766kmol/h；
13 #: -46.69 deg.C, 1.1MPa, 938.732kmol/H of a liquid wherein H2:1.00kmol/h、CO:0.0898kmol/h、CO2:893.039kmol/h、CH3OH:44.602kmol/h；
40736kg/h of crude liquid carbon dioxide are obtained in the process, 47.5766% of the carbon dioxide in the carbon dioxide-rich methanol is liquefied.
Working condition 2
Heating the carbon dioxide-rich methanol (03) to 65 ℃, wherein the desorption pressure of a flash tank (V1) is 1.5Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.1Mpa
01 #: -18.5 ℃, 3.2Mpa, 8500kmol/H of a liquid wherein H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
02 #: 34.982 deg.C, 3.19Mpa, 8500kmol/H gas-liquid mixture, wherein H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
03 #: 65 ℃ and 3.18MPa, 8500kmol/H of a gas-liquid mixture in which H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
05 #: 55.036 deg.C, 1.5Mpa, 6975.83kmol/H of liquid, wherein H2:0.42463kmol/h、CO:0.01653kmol/h、CO2:465.764kmol/h、CH3OH:6509.62kmol/h；
07 #: -14.5 ℃ at 1.49MPa 6975.83kmol/H of a liquid wherein H2:0.42463kmol/h、CO:0.01653kmol/h、CO2:465.764kmol/h、CH3OH:6509.62kmol/h；
08#: 55.036 deg.C, 1.5Mpa, 1524.17kmol/H gas, wherein H2:30.4304kmol/h、CO:0.578467kmol/h、CO2:1411.29kmol/h、CH3OH:81.8726kmol/h；
09 #: -36 ℃ and 1.49MPa 1524.17kmol/H of a gas-liquid mixture wherein H2:30.4304kmol/h、CO:0.578467kmol/h、CO2:1411.29kmol/h、CH3OH:81.8726kmol/h；
11 #: -42.36 ℃ under 1.1MPa 195.64kmol/H of a gas wherein H2:29.557kmol/h、CO:0.50133kmol/h、CO2:165.561kmol/h、CH3OH:0.02042kmol/h；
13 #: -42.36 ℃ 1.1MPa 1328.53kmol/H of a liquid wherein H2:0.8734kmol/h、CO:0.07714kmol/h、CO2:1245.73kmol/h、CH3OH:81.8521kmol/h；
57451kg/h of crude liquid carbon dioxide are obtained in the process, 66.3661% of carbon dioxide in carbon dioxide-rich methanol is liquefied.
Working condition 3
Heating the carbon dioxide-rich methanol (03) to 40 ℃, wherein the desorption pressure of a flash tank (V1) is 3.0Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.1Mpa
01 #: -18.5 ℃, 3.2Mpa, 8500kmol/H of a liquid wherein H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
02 #: 29.192 deg.C, 3.19Mpa, 8500kmol/H gas-liquid mixture, wherein H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
03 #: a gas-liquid mixture of 40 ℃, 3.18Mpa and 8500kmol/H, wherein H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
05 #: 38.953 deg.C, 3.0Mpa, 7964.8kmol/H of liquid, wherein H2:2.96874kmol/h、CO:0.108215kmol/h、CO2:1377.8kmol/h、CH3OH:6583.92kmol/h；
07 #: -14.5 ℃, 2.99MPa, 7964.8kmol/H of a liquid wherein H2:2.96874kmol/h、CO:0.108215kmol/h、CO2:1377.8kmol/h、CH3OH:6583.92kmol/h；
08#: 38.9529 deg.C, 3.0Mpa, 535.204kmol/H gas, wherein H2:27.8863kmol/h、CO:0.486785kmol/h、CO2:499.254kmol/h、CH3OH:7.5769kmol/h；
09 #: -36 ℃ and 2.99MPa 535.204kmol/H of a gas-liquid mixture, wherein H2:27.8863kmol/h、CO:0.486785kmol/h、CO2:499.254kmol/h、CH3OH:7.5769kmol/h；
11 #: -49 ℃ and 1.1MPa 84.9536kmol/H of a gas, wherein H2:27.3059kmol/h、CO:0.431692kmol/h、CO2:57.2119kmol/h、CH3OH:0.00416kmol/h；
13 #: at-49 ℃ and 1.1MPa 450.25kmol/hLiquid in which H2:0.580403kmol/h、CO:0.0551kmol/h、CO2:442.042kmol/h、CH3OH:7.57269kmol/h；
19699.5kg/h of crude liquid carbon dioxide are obtained in the process, 23.5497% of carbon dioxide in carbon dioxide-rich methanol is liquefied.
Working condition 4
Heating the carbon dioxide-rich methanol (03) to 40 ℃, wherein the desorption pressure of a flash tank (V1) is 1.5Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.1Mpa
01 #: -18.5 ℃, 3.2Mpa, 8500kmol/H of a liquid wherein H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
02 #: 17.192 deg.C, 3.19Mpa, 8500kmol/H gas-liquid mixture, wherein H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
03 #: a gas-liquid mixture of 40 ℃, 3.18Mpa and 8500kmol/H, wherein H2:30.855kmol/h、CO:0.595kmol/h、CO2:1877.06kmol/h、CH3OH:6591.5kmol/h；
05 #: 27.33 ℃, 1.5Mpa, 7346.9kmol/H of liquid, wherein H2:0.571254kmol/h、CO:0.0240845kmol/h、CO2:771.508kmol/h、CH3OH:6574.77kmol/h；
07 #: -14.5 ℃ at 1.49MPa 7346.9kmol/H of a liquid wherein H2:0.571254kmol/h、CO:0.0240845kmol/h、CO2:771.508kmol/h、CH3OH:6574.77kmol/h；
08#: 27.3296 deg.C, 1.5Mpa, 1153.13kmol/H gas, wherein H2:30.2838kmol/h、CO:0.570916kmol/h、CO2:1105.55kmol/h、CH3OH:16.7289kmol/h；
09 #: -36 ℃ and 1.49MPa 1153.13kmol/H of a gas-liquid mixture wherein H2:30.2838kmol/h、CO:0.570916kmol/h、CO2:1105.55kmol/h、CH3OH:16.7289kmol/h；
11 #: -42.7 ℃ under 1.1MPa 190.007kmol/H of a gas wherein H2:29.6054kmol/h、CO:0.50835kmol/h、CO2:159.877kmol/h、CH3OH:0.01626kmol/h；
13 #: -42.7 ℃ at 1.1MPa 963.123kmol/H of a liquid wherein H2:0.678334kmol/h、CO:0.0625659kmol/h、CO2:945.67kmol/h、CH3OH:16.7126kmol/h；
42157.4kg/h of crude liquid carbon dioxide are obtained in the process, and 50.38% of carbon dioxide in the carbon dioxide-rich methanol is liquefied.
Example 2
Gas purification process for preparing methanol by low-temperature methanol washing with pressure grade of 3.5Mpa
3.2Mpa, -18.5 ℃ and 8500kmol/H, and the composition is H2：28.75kmol/h，CO:43.15kmol/h，CO2:1488.8kmol/h，CH36939.3kmol/h low-temperature methanol washing process, wherein carbon dioxide-rich methanol (01) which absorbs carbon dioxide and is at the outlet of a carbon washing tower is preheated by a heat exchanger (E1) and heated by a heat exchanger (E2); reducing the pressure of the heated carbon dioxide-rich methanol (03) through a pressure control valve (PV1), feeding a gas-liquid mixed medium (04) after the pressure control valve (PV1) into a flash tank (V1) for analysis, regulating the amount of methanol (05) output from the bottom of the flash tank (V1) through a liquid level control valve (LV1), controlling the liquid level of the flash tank (V1), reducing the temperature of the methanol (06) output from the liquid level control valve (LV1) through a heat exchanger (E1), and feeding the methanol (07) cooled to-14.5 ℃ to a downstream process for regeneration; the desorption gas (08) output from the top of the flash tank (V1) is frozen to-36 ℃ through a heat exchanger (E3), the-36 ℃ medium (09) output from the heat exchanger (E3) is decompressed through a pressure control valve (PV2), the decompressed gas-liquid mixed medium (10) enters a gas-liquid separation tank (V2) for gas-liquid separation after the pressure control valve (PV2), and H-containing gas output from the top of the gas-liquid separation tank (V2)2And CO gas (11) is recycled as recycle gas, the amount of liquid carbon dioxide (12) output from the bottom of the gas-liquid separation tank (V2) is adjusted by a liquid level control valve (LV2) so as to control the liquid level of the gas-liquid separation tank (V2), and crude liquid carbon dioxide (13) output from the liquid level control valve (LV2) is sent to a downstream refining process to prepare required product carbon dioxide.
The higher the temperature of the heated carbon dioxide-rich methanol (03) and the lower the pressure of the flash tank (V1), the more gas is desorbed and the higher the yield of liquid carbon dioxide (10) is obtained.
The product parameters output by the device are as follows:
working condition 1
Heating the carbon dioxide-rich methanol (03) to 65 ℃, wherein the desorption pressure of a flash tank (V1) is 3.0Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.1Mpa
01 #: -18.5 ℃, 3.2Mpa, 8500kmol/H of a liquid wherein H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
02 #: 49.67 deg.C, 3.19MPa, 8500kmol/H of a gas-liquid mixture, wherein H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
03 #: 65 ℃ and 3.18MPa, 8500kmol/H of a gas-liquid mixture in which H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
05 #: 64.265 deg.C, 3.00Mpa, 7786.42kmol/H liquid, wherein H2:2.04979kmol/h、CO:5.59133kmol/h、CO2:870.1kmol/h、CH3OH:6908.68kmol/h；
07 #: -14.5 ℃, 2.99MPa, 7786.42kmol/H of a liquid wherein H2:2.04979kmol/h、CO:5.59133kmol/h、CO2:870.1kmol/h、CH3OH:6908.68kmol/h；
08#: 64.265 deg.C, 3.00Mpa, 713.581kmol/H gas, wherein H2:26.7kmol/h、CO:37.5587kmol/h、CO2:618.699kmol/h、CH3OH:30.6231kmol/h；
09 #: -36 ℃ and 2.99MPa 713.581kmol/H of a gas-liquid mixture, wherein H2:26.7kmol/h、CO:37.5587kmol/h、CO2:618.699kmol/h、CH3OH:30.6231kmol/h；
11 #: -51.5376 deg.C, 1.1MPa, 156.788kmol/H of a gas wherein H2:26.3426kmol/h、CO:34.7086kmol/h、CO2:95.7292kmol/h、CH3OH:0.007093kmol/h；
13 #: -51.5376 deg.C, 1.1MPa, 556.794kmol/H of a liquid wherein H2:0.357598kmol/h、CO:2.85005kmol/h、CO2:522.97kmol/h、CH3OH:30.616kmol/h；
24077.4kg/h of crude liquid carbon dioxide are obtained in the process, 35.1269% of carbon dioxide in carbon dioxide-rich methanol is liquefied.
Working condition 2
Heating the carbon dioxide-rich methanol (03) to 65 ℃, wherein the desorption pressure of a flash tank (V1) is 1.5Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.1Mpa
01 #: -18.5 ℃, 3.2Mpa, 8500kmol/H of a liquid wherein H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
02 #: 40.214 deg.C, 3.19Mpa, 8500kmol/H gas-liquid mixture, wherein H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
03 #: 65 ℃ and 3.18MPa, 8500kmol/H of a gas-liquid mixture in which H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
05 #: 56.228 deg.C, 1.5Mpa, 7334.1kmol/H of liquid, wherein H2:0.538718kmol/h、CO:1.61952kmol/h、CO2:458.591kmol/h、CH3OH:6873.35kmol/h；
07 #: -14.5 ℃ at 1.49MPa 7334.1kmol/H of a liquid wherein H2:0.538718kmol/h、CO:1.61952kmol/h、CO2:458.591kmol/h、CH3OH:6873.35kmol/h；
08#: 56.228 deg.C, 1.5Mpa, 1165.9kmol/H gas, wherein H2:28.2113kmol/h、CO:41.5305kmol/h、CO2:1030.219kmol/h、CH3OH:65.9533kmol/h；
09 #: -36 ℃ and 1.49MPa 1165.9kmol/H of a gas-liquid mixture wherein H2:28.2113kmol/h、CO:41.5305kmol/h、CO2:1030.219kmol/h、CH3OH:65.9533kmol/h；
11 #: -43.4434 deg.C, 1.1MPa, 362.296kmol/H of a gas wherein H2:27.9485kmol/h、CO:39.5906kmol/h、CO2:294.722kmol/h、CH3OH:0.0354724kmol/h；
13#：-43.4434℃、1.1Mpa、803.607kmol/H of a liquid in which H2:0.262837kmol/h、CO:1.9399kmol/h、CO2:735.486kmol/h、CH3OH:65.9178kmol/h；
34535.6kg/h of crude liquid carbon dioxide are obtained in the process, and 49.4% of carbon dioxide in the carbon dioxide-rich methanol is liquefied.
Working condition 3
Heating the carbon dioxide-rich methanol (03) to 40 ℃, wherein the desorption pressure of a flash tank (V1) is 3.0Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.1Mpa
01 #: -18.5 ℃, 3.2Mpa, 8500kmol/H of a liquid wherein H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
02 #: 31.468 deg.C, 3.19Mpa, 8500kmol/H gas-liquid mixture, wherein H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
03 #: a gas-liquid mixture of 40 ℃, 3.18Mpa and 8500kmol/H, wherein H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
05 #: 39.353 deg.C, 3.0Mpa, 8147.72kmol/H of liquid, wherein H2:3.88782kmol/h、CO:10.6362kmol/h、CO2:1199kmol/h、CH3OH:6934.19kmol/h；
07 #: -14.5 ℃, 2.99MPa, 8147.72kmol/H of a liquid wherein H2:3.88782kmol/h、CO:10.6362kmol/h、CO2:1199kmol/h、CH3OH:6934.19kmol/h；
08#: 39.353 deg.C, 3MPa, 352.284kmol/H gas, wherein H2:24.8622kmol/h、CO:32.5139kmol/h、CO2:289.796kmol/h、CH3OH:5.112kmol/h；
09 #: -36 ℃ and 2.99MPa 352.284kmol/H of a gas-liquid mixture, wherein H2:24.8622kmol/h、CO:32.5139kmol/h、CO2:289.796kmol/h、CH3OH:5.112kmol/h；
11 #: -52.1279 deg.C, 1.1MPa, 125.464kmol/H of a gas wherein H2:24.6947kmol/h、CO:31.1443kmol/h、CO2:69.6206kmol/h、CH3OH:0.004034kmol/h；
13 #: -52.1279 deg.C, 1.1MPa, 226.821kmol/H of a liquid wherein H2:0.16748kmol/h、CO:1.36952kmol/h、CO2:220.176kmol/h、CH3OH:5.10804kmol/h；
9892.26kg/h of crude liquid carbon dioxide are obtained in the process, 14.788% of carbon dioxide in carbon dioxide-rich methanol is liquefied.
Working condition 4
Heating the carbon dioxide-rich methanol (03) to 40 ℃, wherein the desorption pressure of a flash tank (V1) is 1.5Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.1Mpa
01 #: -18.5 ℃, 3.2Mpa, 8500kmol/H of a liquid wherein H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
02 #: 21.115 deg.C, 3.19Mpa, 8500kmol/H gas-liquid mixture, wherein H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
03 #: a gas-liquid mixture of 40 ℃, 3.18Mpa and 8500kmol/H, wherein H2:28.75kmol/h、CO:43.15kmol/h、CO2:1488.8kmol/h、CH3OH:6939.3kmol/h；
05 #: at 30.31 deg.C and 1.5MPa 7639.72kmol/H, wherein H2:0.726973kmol/h、CO:2.34366kmol/h、CO2:711.936kmol/h、CH3OH:6924.71kmol/h；
07 #: -14.5 ℃ at 1.49MPa 7639.72kmol/H of a liquid wherein H2:0.726973kmol/h、CO:2.34366kmol/h、CO2:711.936kmol/h、CH3OH:6924.71kmol/h；
08#: at 30.31 deg.C, 1.5MPa, 860.28kmol/H gas, wherein H2:28.023kmol/h、CO:40.8063kmol/h、CO2:776.864kmol/h、CH3OH:14.5871kmol/h；
09 #: -36 ℃ and 1.49MPa 860.28kmol/H of a gas-liquid mixture wherein H2:28.023kmol/h、CO:40.8063kmol/h、CO2:776.864kmol/h、CH3OH:14.5871kmol/h；
11 #: -43.6462 ℃, 1.1MPa, 360.041kmol/h of gas,wherein H2:27.8508kmol/h、CO:39.4891kmol/h、CO2:292.67kmol/h、CH3OH:0.03088kmol/h；
13 #: -43.6462 deg.C, 1.1MPa, 500.239kmol/H of a liquid wherein H2:0.172238kmol/h、CO:1.31729kmol/h、CO2:484.193kmol/h、CH3OH:14.5562kmol/h；
21812.9kg/h of crude liquid carbon dioxide are obtained in the process, and 32.52% of carbon dioxide in the carbon dioxide-rich methanol is liquefied.
Example 3
Body purification process for preparing methanol by low-temperature methanol washing with pressure grade of 5.6Mpa
5.53Mpa, -14.5 ℃, 11758kmol/H, and the composition is H2：52.45kmol/h，CO:1.55kmol/h，CO2:3848kmol/h，CH37856kmol/h of low-temperature methanol washing process, wherein carbon dioxide-rich methanol (01) which absorbs carbon dioxide and is at the outlet of a carbon washing tower is preheated by a heat exchanger (E1) and heated by a heat exchanger (E2); reducing the pressure of the heated carbon dioxide-rich methanol (03) through a pressure control valve (PV1), feeding a gas-liquid mixed medium (04) after the pressure control valve (PV1) into a flash tank (V1) for analysis, regulating the amount of methanol (05) output from the bottom of the flash tank (V1) through a liquid level control valve (LV1), controlling the liquid level of the flash tank (V1), reducing the temperature of the methanol (06) output from the liquid level control valve (LV1) through a heat exchanger (E1), and feeding the methanol (07) with the temperature reduced to-10.5 ℃ to a downstream process for regeneration; the desorption gas (08) output from the top of the flash tank (V1) is frozen to-36 ℃ through a heat exchanger (E3), the-36 ℃ medium (09) output from the heat exchanger (E3) is decompressed through a pressure control valve (PV2), the decompressed gas-liquid mixed medium (10) enters a gas-liquid separation tank (V2) for gas-liquid separation after the pressure control valve (PV2), and H-containing gas output from the top of the gas-liquid separation tank (V2)2And CO gas (11) is recycled as recycle gas, the amount of liquid carbon dioxide (12) output from the bottom of the gas-liquid separation tank (V2) is adjusted by a liquid level control valve (LV2) so as to control the liquid level of the gas-liquid separation tank (V2), and crude liquid carbon dioxide (13) output from the liquid level control valve (LV2) is sent to a downstream refining process to prepare required product carbon dioxide.
The higher the temperature of the heated carbon dioxide-rich methanol (03) and the lower the pressure of the flash tank (V1), the more gas is desorbed and the higher the yield of liquid carbon dioxide (10) is obtained.
The product parameters output by the device are as follows:
working condition 1
Heating the carbon dioxide-rich methanol (03) to 65 ℃, wherein the analytic pressure of a flash tank (V1) is 4.0Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.3Mpa
01 #: -14.5 ℃ 5.53MPa 11758kmol/H of a liquid wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
02 #: 39.363 deg.C, 5.52Mpa, 11758kmol/H gas-liquid mixture, wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
03 #: a gas-liquid mixture at 65 ℃ and 5.51Mpa 11758kmol/H, wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
05 #: 58.088 deg.C, 4.00Mpa, 9522.43kmol/H liquid, wherein H2:2.3kmol/h、CO:0.12558kmol/h、CO2:1723.46kmol/h、CH3OH:7796.55kmol/h；
07 #: -10.5 ℃, 3.99MPa, 9522.43kmol/H of a liquid, wherein H2:2.3kmol/h、CO:0.12558kmol/h、CO2:1723.46kmol/h、CH3OH:7796.55kmol/h；
08#: 58.088 deg.C, 4.00Mpa, 2235.57kmol/H gas, wherein H2:50.1495kmol/h、CO:1.42442kmol/h、CO2:2124.54kmol/h、CH3OH:59.4559kmol/h；
09 #: -36 ℃ 3.99MPa 2235.57kmol/H of a gas-liquid mixture wherein H2:50.1495kmol/h、CO:1.42442kmol/h、CO2:2124.54kmol/h、CH3OH:59.4559kmol/h；
11 #: -43.3294 deg.C, 1.3MPa, 165.92kmol/H of a gas wherein H2:47.1051kmol/h、CO:1.057146kmol/h、CO2:117.745kmol/h、CH3OH:0.0126288kmol/h；
13 #: -43.3294 deg.C, 1.3MPa, 2069.65kmol/H of a liquid wherein H2:3.04446kmol/h、CO:0.367276kmol/h、CO2:2006.8kmol/h、CH3OH:59.4433kmol/h；
90239.8kg/h of crude liquid carbon dioxide are obtained in the process, 52.1517% of carbon dioxide in carbon dioxide-rich methanol is liquefied.
Working condition 2
Heating the carbon dioxide-rich methanol (03) to 65 ℃, the desorption pressure of a flash tank (V1) being 2.0Mpa, and the pressure of a gas-liquid separation tank (V2) being 1.3Mpa
01 #: -14.5 ℃ 5.53MPa 11758kmol/H of a liquid wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
02 #: 27.391 deg.C, 5.52Mpa, 11758kmol/H gas-liquid mixture, wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
03 #: a gas-liquid mixture at 65 ℃ and 5.51Mpa 11758kmol/H, wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
05 #: a liquid at 45.91 ℃ and 2.00MPa and 8680.25kmol/H, wherein H2:0.62kmol/h、CO:0.0377kmol/h、CO2:908.777kmol/h、CH3OH:7770.81kmol/h；
07 #: -10.5 ℃, 1.99MPa, 8680.25kmol/H of a liquid, wherein H2:0.62kmol/h、CO:0.0377kmol/h、CO2:908.777kmol/h、CH3OH:7770.81kmol/h；
08#: at 45.91 deg.C, 2.00MPa, 3077.76kmol/H gas, wherein H2:51.8296kmol/h、CO:1.51228kmol/h、CO2:2939.23kmol/h、CH3OH:85.19kmol/h；
09 #: -36 ℃ and 1.99MPa 3077.76kmol/H of a gas-liquid mixture wherein H2:51.8296kmol/h、CO:1.51228kmol/h、CO2:2939.23kmol/h、CH3OH:85.19kmol/h；
11 #: -41.0546 deg.C, 1.3MPa, 211.427kmol/H of a gas wherein H2:48.29181kmol/h、CO:1.0969kmol/h、CO2:162.0195kmol/h、CH3OH:0.01966588kmol/h；
13 #: -41.0546 deg.C, 1.3MPa, 2866.17kmol/H of a liquid wherein H2:3.53775kmol/h、CO:0.41538kmol/h、CO2:2777.21kmol/h、CH3OH:85.17kmol/h；
124972kg/h of crude liquid carbon dioxide are obtained in the process, 72.1727% of carbon dioxide in carbon dioxide-rich methanol is liquefied.
Working condition 3
Heating the carbon dioxide-rich methanol (03) to 45 ℃, wherein the desorption pressure of a flash tank (V1) is 4.0Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.3Mpa
01 #: -14.5 ℃ 5.53MPa 11758kmol/H of a liquid wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
02 #: 28.124 deg.C, 5.52Mpa, 11758kmol/H gas-liquid mixture, wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
03 #: a gas-liquid mixture at 45 ℃ and 5.51Mpa, 11758kmol/H, wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
05 #: 37.358 deg.C, 4.00Mpa, 10463.5kmol/H liquid, wherein H2:4.4012kmol/h、CO:0.244718kmol/h、CO2:2616.46kmol/h、CH3OH:7842.4kmol/h；
07 #: -10.5 ℃, 3.99MPa, 10463.5kmol/H of a liquid, wherein H2:4.4012kmol/h、CO:0.244718kmol/h、CO2:2616.46kmol/h、CH3OH:7842.4kmol/h；
08#: 37.3581 deg.C, 4.00Mpa, 1294.52kmol/H gas, wherein H2:48.0489kmol/h、CO:1.30529kmol/h、CO2:1231.57kmol/h、CH3OH:13.6018kmol/h；
09 #: -36 ℃ 3.99MPa 1294.52kmol/H of a gas-liquid mixture wherein H2:48.0489kmol/h、CO:1.30529kmol/h、CO2:1231.57kmol/h、CH3OH:13.6018kmol/h；
11 #: -45.4335 deg.C, 1.3MPa, 139.283kmol/H of a gas wherein H2:46.1131kmol/h、CO:1.0557kmol/h、CO2:92.1062kmol/h、CH3OH:0.00761523kmol/h；
13 #: -45.4335 deg.C, 1.3MPa, 1155.24kmol/H of a liquid wherein H2:1.93589kmol/h、CO:0.249586kmol/h、CO2:2777.21kmol/h、CH3OH:13.59427kmol/h；
50593.9kg/h of crude liquid carbon dioxide are obtained in the process, 29.6118% of carbon dioxide in carbon dioxide-rich methanol is liquefied.
Working condition 4
Heating the carbon dioxide-rich methanol (03) to 45 ℃, wherein the desorption pressure of a flash tank (V1) is 2.0Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.3Mpa
01 #: -14.5 ℃ 5.53MPa 11758kmol/H of a liquid wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
02 #: 11 ℃ and 11758kmol/H of a gas-liquid mixture at 5.52MPa, wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
03 #: a gas-liquid mixture at 45 ℃ and 5.51Mpa, 11758kmol/H, wherein H2:52.45kmol/h、CO: 1.55kmol/h、CO2:3848kmol/h、CH3OH:7856kmol/h；
05 #: 21.478 deg.C, 2.00Mpa, 9345.91kmol/H liquid, wherein H2:0.8643112kmol/h、CO:0.0567kmol/h、CO2:1508.7kmol/h、CH3OH:7836.28kmol/h；
07 #: -10.5 ℃, 1.99MPa, 9345.91kmol/H of a liquid, wherein H2:0.8643112kmol/h、CO:0.0567kmol/h、CO2:1508.7kmol/h、CH3OH:7836.28kmol/h；
08#: 21.4778 deg.C, 2.00Mpa, 2412.07kmol/H gas, wherein H2:51.5857kmol/h、CO:1.49329kmol/h、CO2:2339.28kmol/h、CH3OH:19.7175kmol/h；
09 #: -36 ℃ under 1.99MPa of 2412.07kmol/H of a gas in which H is2:51.5857kmol/h、CO:1.49329kmol/h、CO2:2339.28kmol/h、CH3OH:19.7175kmol/h；
11#: -41.616 deg.C, 1.3MPa, 203.419kmol/H of a gas wherein H2:48.6968kmol/h、CO:1.13725kmol/h、CO2:153.571kmol/h、CH3OH:0.01444kmol/h；
13 #: -41.616 deg.C, 1.3MPa, 2208.65kmol/H of a liquid wherein H2:2.88884kmol/h、CO:0.356038kmol/h、CO2:2185.7kmol/h、CH3OH:19.703kmol/h；
96839.5kg/h of crude liquid carbon dioxide are obtained in the process, and 56.8% of carbon dioxide in the carbon dioxide-rich methanol is liquefied.
Example 4
Body purification process for preparing methanol by low-temperature methanol washing with pressure grade of 5.6Mpa
5.53Mpa, -15.9 ℃, 10792.4kmol/H, and the composition is H2：46.12kmol/h，CO:74.84kmol/h，CO2:2886kmol/h，CH37785.44kmol/h low-temperature methanol washing process, wherein carbon dioxide-rich methanol (01) which absorbs carbon dioxide and is at the outlet of a carbon washing tower is preheated by a heat exchanger (E1) and heated by a heat exchanger (E2); reducing the pressure of the heated carbon dioxide-rich methanol (03) through a pressure control valve (PV1), feeding a gas-liquid mixed medium (04) after the pressure control valve (PV1) into a flash tank (V1) for analysis, regulating the amount of methanol (05) output from the bottom of the flash tank (V1) through a liquid level control valve (LV1), controlling the liquid level of the flash tank (V1), reducing the temperature of the methanol (06) output from the liquid level control valve (LV1) through a heat exchanger (E1), and feeding the methanol (07) cooled to-11.9 ℃ to a downstream process for regeneration; the desorption gas (08) output from the top of the flash tank (V1) is frozen to-36 ℃ through a heat exchanger (E3), the-36 ℃ medium (09) output from the heat exchanger (E3) is decompressed through a pressure control valve (PV2), the decompressed gas-liquid mixed medium (10) enters a gas-liquid separation tank (V2) for gas-liquid separation after the pressure control valve (PV2), and H-containing gas output from the top of the gas-liquid separation tank (V2)2And CO gas (11) is recycled as recycle gas, the amount of liquid carbon dioxide (12) output from the bottom of the gas-liquid separation tank (V2) is adjusted by a liquid level control valve (LV2) so as to control the liquid level of the gas-liquid separation tank (V2), and crude liquid carbon dioxide (13) output from the liquid level control valve (LV2) is sent to a downstream refining process to prepare required product carbon dioxide.
The higher the temperature of the heated carbon dioxide-rich methanol (03) and the lower the pressure of the flash tank (V1), the more gas is desorbed and the higher the yield of liquid carbon dioxide (10) is obtained.
Working condition 1
Heating the carbon dioxide-rich methanol (03) to 65 ℃, wherein the analytic pressure of a flash tank (V1) is 4.0Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.3Mpa
01 #: -15.9 ℃, 5.53MPa, 10792.4kmol/H of a liquid, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
02 #: 43.565 deg.C, 5.52Mpa, 10792.4kmol/H gas-liquid mixture, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
03 #: a gas-liquid mixture at 65 ℃ and 5.51Mpa 10792.4kmol/H, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
05 #: 59.304 deg.C, 4.00Mpa, 9296.97kmol/H liquid, wherein H2:2.8093kmol/h、CO:8.29336kmol/h、CO2:1542.31kmol/h、CH3OH:7743.56kmol/h；
07 #: -11.9 ℃, 3.99MPa, 9296.97kmol/H of a liquid wherein H2:2.8093kmol/h、CO:8.29336kmol/h、CO2:1542.31kmol/h、CH3OH:7743.56kmol/h；
08#: 59.304 deg.C, 4.00Mpa, 1495.43kmol/H gas, wherein H2:43.31kmol/h、CO:66.5466kmol/h、CO2:1343.69kmol/h、CH3OH:41.8839kmol/h；
09 #: -36 ℃ 3.99MPa 1495.43kmol/H of a gas-liquid mixture wherein H2:43.31kmol/h、CO:66.5466kmol/h、CO2:1343.69kmol/h、CH3OH:41.8839kmol/h；
11 #: -48.808 deg.C, 1.3MPa, 241.713kmol/H of a gas wherein H2:42.2529kmol/h、CO:58.0911kmol/h、CO2:141.357kmol/h、CH3OH:0.01164kmol/h；
13 #: -48.808 deg.C, 1.3MPa, 1253.72kmol/H of a liquid wherein H2:1.05784kmol/h、CO:8.45555kmol/h、CO2:1202.33kmol/h、CH3OH:41.8722kmol/h；
54495kg/h of crude liquid carbon dioxide are obtained in the process, and 41.66% of carbon dioxide in the carbon dioxide-rich methanol is liquefied.
Working condition 2
Heating the carbon dioxide-rich methanol (03) to 65 ℃, the desorption pressure of a flash tank (V1) being 2.0Mpa, and the pressure of a gas-liquid separation tank (V2) being 1.3Mpa
01 #: -15.9 ℃, 5.53MPa, 10792.4kmol/H of a liquid, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
02 #: 31.504 deg.C, 5.52Mpa, 10792.4kmol/H gas-liquid mixture, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
03 #: a gas-liquid mixture at 65 ℃ and 5.51Mpa 10792.4kmol/H, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
05 #: 48.4145 deg.C, 2.00Mpa, 8542.59kmol/H liquid, wherein H2:0.7260392kmol/h、CO:2.39704kmol/h、CO2:823.853kmol/h、CH3OH:7715.61kmol/h；
07 #: -11.9 ℃ at 1.99MPa 8542.59kmol/H of a liquid wherein H2:0.7260392kmol/h、CO:2.39704kmol/h、CO2:823.853kmol/h、CH3OH:7715.61kmol/h；
48.415 deg.C, 2.00Mpa, 2249.82kmol/H gas, wherein H2:45.394kmol/h、CO:72.443kmol/h、CO2:2062.15kmol/h、CH3OH:69.8289kmol/h；
09 #: -36 ℃ and 1.99MPa 2249.82kmol/H of a gas-liquid mixture wherein H2:45.394kmol/h、CO:72.443kmol/h、CO2:2062.15kmol/h、CH3OH:69.8289kmol/h；
11 #: -43.647 deg.C, 1.3MPa, 359.499kmol/H of a gas wherein H2:44.1768kmol/h、CO:63.172kmol/h、CO2:252.122kmol/h、CH3OH:0.027717kmol/h；
13 #: -43.647 deg.C, 1.3MPa, 1890.32kmol/H of a liquid wherein H2:1.217184kmol/h、CO:9.271kmol/h、CO2:1810.03kmol/h、CH3OH:69.8012kmol/h；
82157.7kg/h of crude liquid carbon dioxide are obtained in the process, 62.7175% of carbon dioxide in carbon dioxide-rich methanol is liquefied.
Working condition 3
Heating the carbon dioxide-rich methanol (03) to 45 ℃, wherein the desorption pressure of a flash tank (V1) is 4.0Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.3Mpa
01 #: -15.9 ℃, 5.53MPa, 10792.4kmol/H of a liquid, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
02 #: 30.983 deg.C, 5.52Mpa, 10792.4kmol/H gas-liquid mixture, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
03 #: a gas-liquid mixture at 45 ℃ and 5.51Mpa, 10792.4kmol/H, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
05 #:39.847 deg.C, 4.00Mpa, 9900kmol/H liquid, wherein H2:4.820271kmol/h、CO:14.3804kmol/h、CO2:2105.98kmol/h、CH3OH:7774.82kmol/h；
07 #: -11.9 ℃, 3.99MPa, 9900kmol/H of a liquid, wherein H2:4.820271kmol/h、CO:14.3804kmol/h、CO2:2105.98kmol/h、CH3OH:7774.82kmol/h；
39.847 deg.C, 4.00Mpa, 892.413kmol/H gas, wherein H2:41.2998kmol/h、CO:60.4599kmol/h、CO2:780.037kmol/h、CH3OH:10.61621kmol/h；
09 #: -36 ℃ 3.99MPa 892.413kmol/H of a gas-liquid mixture wherein H2:41.2998kmol/h、CO:60.4599kmol/h、CO2:780.037kmol/h、CH3OH:10.61621kmol/h；
11 #: -51.1775 ℃, 1.3MPa, 207.087kmol/h of gas,wherein H2:40.666kmol/h、CO:55.1868kmol/h、CO2:111.227kmol/h、CH3OH:0.00723503kmol/h；
13 #: -51.1775 deg.C, 1.3MPa, 685.326kmol/H of a liquid wherein H2:0.633833kmol/h、CO:5.27312kmol/h、CO2:668.81kmol/h、CH3OH:10.609kmol/h；
29923.1kg/h of crude liquid carbon dioxide are obtained in the process, 23.1743% of carbon dioxide in carbon dioxide-rich methanol is liquefied.
Working condition 4
Heating the carbon dioxide-rich methanol (03) to 45 ℃, wherein the desorption pressure of a flash tank (V1) is 2.0Mpa, and the pressure of a gas-liquid separation tank (V2) is 1.3Mpa
01 #: -15.9 ℃, 5.53MPa, 10792.4kmol/H of a liquid, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
02 #: 16.523 deg.C, 5.52Mpa, 10792.4kmol/H gas-liquid mixture, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
03 #: a gas-liquid mixture at 45 ℃ and 5.51Mpa, 10792.4kmol/H, wherein H2:46.12kmol/h、CO: 74.84kmol/h、CO2:2886kmol/h、CH3OH:7785.44kmol/h；
05 #: 26.8875 deg.C, 2.00Mpa, 9005.191kmol/H liquid, wherein H2:0.957017kmol/h、CO:3.36293kmol/h、CO2:1235.01kmol/h、CH3OH:7765.87kmol/h；
07 #: -11.9 ℃ at 1.99MPa 9005.191kmol/H of a liquid wherein H2:0.957017kmol/h、CO:3.36293kmol/h、CO2:1235.01kmol/h、CH3OH:7765.87kmol/h；
08#: 26.8875 deg.C, 2.00Mpa, 1787.21kmol/H gas, wherein H2:45.163kmol/h、CO:71.4771kmol/h、CO2:1651kmol/h、CH3OH:19.5733kmol/h；
09 #: -36 ℃ and 1.99MPa 1787.21kmol/H of a gas-liquid mixture wherein H2:45.163kmol/h、CO:71.4771kmol/h、CO2:1651kmol/h、CH3OH:19.5733kmol/h；
11 #: -44.1324 deg.C, 1.3MPa, 351.402kmol/H of a gas wherein H2:44.2022kmol/h、CO:63.9172kmol/h、CO2:243.26kmol/h、CH3OH:0.0223141kmol/h；
13 #: -44.1324 deg.C, 1.3MPa, 1435.81kmol/H of a liquid wherein H2:0.960757kmol/h、CO:7.55992kmol/h、CO2:1407.74kmol/h、CH3OH:19.551kmol/h；
62794.3kg/h of crude liquid carbon dioxide are obtained in the process, 48.7781% of carbon dioxide in carbon dioxide-rich methanol is liquefied.
Claims (10)
1. A device for preparing liquid carbon dioxide in a low-temperature methanol washing process is characterized in that: the device comprises a heat exchanger E1, a heat exchanger E2 and a flash tank V1 which are arranged in sequence, wherein a gas-phase outlet of the flash tank V1 is connected to a gas-liquid separation tank V2 through a first heat exchanger E3, and a liquid-phase outlet of the gas-liquid separation tank V2 is a liquid carbon dioxide outlet; and a liquid phase outlet of the flash tank V1 is connected to a methanol collecting system after heat exchange by taking a heat exchanger E1 as a heat exchange medium.
2. The apparatus of claim 1, wherein: a pressure control valve PV1 is arranged on a pipeline between the heat exchanger E2 and the flash tank V1; a pressure control valve PV2 is arranged on a pipeline between the flash tank V1 and the gas-liquid separation tank V2.
3. The apparatus of claim 1, wherein: a liquid level control valve LV1 is arranged on a pipeline between the liquid phase outlet of the flash tank V1 and the heat exchanger E1, and a liquid level control valve LV2 is arranged on a pipeline at the liquid phase outlet of the gas-liquid separation tank V2.
4. The method for preparing liquid carbon dioxide in the low-temperature methanol washing process according to any one of claims 1 to 3 is characterized by comprising the following steps:
s1, heating the carbon dioxide-rich methanol obtained from the low-temperature methanol washing process, and then feeding the heated carbon dioxide-rich methanol into a flash tank for thermal desorption;
and S2, carrying out gas-liquid separation on the gas separated by thermal desorption after heat exchange and condensation to obtain liquid carbon dioxide.
5. The method of claim 4, wherein: liquid methanol thermally resolved by the flash tank is conveyed to a heat exchanger E1 through a pipeline to be used as a heat exchange medium of the heat exchanger E1 for preheating carbon dioxide-rich methanol.
6. The method of claim 4, wherein: the pressure of the carbon dioxide-rich methanol obtained by the low-temperature methanol washing process is 3-5.6 MPa.
7. The method of claim 4, wherein: the temperature of the carbon dioxide-rich methanol is above 40 ℃ after heating.
8. The method of claim 4, wherein: when the flash tank carries out thermal desorption, the pressure is 1.5-4 MPa.
9. The method of claim 4, wherein: the pressure of the gas-liquid separation tank is controlled to be 1.1-1.3 MPa.
10. The method of claim 4, wherein: the gas phase obtained by gas-liquid separation contains H2And CO gas, recycling; the obtained liquid phase is a crude liquid carbon dioxide product and is sent to a downstream process for refining.
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| CN110093191A (en) * | 2019-04-19 | 2019-08-06 | 崔静思 | A kind of low-temp methanol washes the recyclable device and method of effective gas in the process |
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| CN115501632A (en) * | 2022-10-19 | 2022-12-23 | 北京石油化工工程有限公司 | Carbon dioxide purification process and carbon dioxide purification system |
| CN115501632B (en) * | 2022-10-19 | 2024-06-04 | 北京石油化工工程有限公司 | Carbon dioxide purification process and carbon dioxide purification system |
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