CN115724819B - Device for preparing ethylene carbonate and preparation method of ethylene carbonate - Google Patents
Device for preparing ethylene carbonate and preparation method of ethylene carbonate Download PDFInfo
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- CN115724819B CN115724819B CN202111001753.0A CN202111001753A CN115724819B CN 115724819 B CN115724819 B CN 115724819B CN 202111001753 A CN202111001753 A CN 202111001753A CN 115724819 B CN115724819 B CN 115724819B
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- KMTRUDSVKNLOMY-UHFFFAOYSA-N Ethylene carbonate Chemical compound O=C1OCCO1 KMTRUDSVKNLOMY-UHFFFAOYSA-N 0.000 title claims abstract description 158
- 238000002360 preparation method Methods 0.000 title abstract description 7
- 238000010521 absorption reaction Methods 0.000 claims abstract description 146
- 239000007788 liquid Substances 0.000 claims abstract description 61
- 238000007670 refining Methods 0.000 claims abstract description 30
- 238000004519 manufacturing process Methods 0.000 claims abstract description 27
- 238000006243 chemical reaction Methods 0.000 claims abstract description 21
- 238000005262 decarbonization Methods 0.000 claims abstract description 18
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 claims description 26
- 239000006096 absorbing agent Substances 0.000 claims description 17
- 238000000034 method Methods 0.000 claims description 14
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 14
- 239000001569 carbon dioxide Substances 0.000 claims description 13
- 229910002092 carbon dioxide Inorganic materials 0.000 claims description 13
- 239000000463 material Substances 0.000 claims description 8
- 230000002745 absorbent Effects 0.000 claims description 7
- 239000002250 absorbent Substances 0.000 claims description 7
- 238000003795 desorption Methods 0.000 claims description 5
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 238000000926 separation method Methods 0.000 claims description 2
- 238000005406 washing Methods 0.000 claims description 2
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 abstract description 107
- 238000005265 energy consumption Methods 0.000 abstract description 7
- 239000007789 gas Substances 0.000 description 44
- 239000000047 product Substances 0.000 description 17
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 11
- 238000010992 reflux Methods 0.000 description 9
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 6
- MTHSVFCYNBDYFN-UHFFFAOYSA-N diethylene glycol Chemical compound OCCOCCO MTHSVFCYNBDYFN-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000012071 phase Substances 0.000 description 6
- 239000002994 raw material Substances 0.000 description 5
- 239000002699 waste material Substances 0.000 description 5
- IKHGUXGNUITLKF-UHFFFAOYSA-N Acetaldehyde Chemical compound CC=O IKHGUXGNUITLKF-UHFFFAOYSA-N 0.000 description 4
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- 239000007795 chemical reaction product Substances 0.000 description 4
- 239000007791 liquid phase Substances 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 4
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 4
- 238000001816 cooling Methods 0.000 description 3
- 238000005261 decarburization Methods 0.000 description 3
- 238000005086 pumping Methods 0.000 description 3
- 239000010865 sewage Substances 0.000 description 3
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 2
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 description 2
- 239000005977 Ethylene Substances 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 2
- 239000003054 catalyst Substances 0.000 description 2
- 238000005202 decontamination Methods 0.000 description 2
- 230000003588 decontaminative effect Effects 0.000 description 2
- 239000003599 detergent Substances 0.000 description 2
- 238000007599 discharging Methods 0.000 description 2
- 239000002360 explosive Substances 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 2
- 229910000027 potassium carbonate Inorganic materials 0.000 description 2
- TYJJADVDDVDEDZ-UHFFFAOYSA-M potassium hydrogencarbonate Chemical compound [K+].OC([O-])=O TYJJADVDDVDEDZ-UHFFFAOYSA-M 0.000 description 2
- 238000011084 recovery Methods 0.000 description 2
- ZIBGPFATKBEMQZ-UHFFFAOYSA-N triethylene glycol Chemical compound OCCOCCOCCO ZIBGPFATKBEMQZ-UHFFFAOYSA-N 0.000 description 2
- 238000004065 wastewater treatment Methods 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-UHFFFAOYSA-N 0.000 description 1
- 241000183024 Populus tremula Species 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 230000000711 cancerogenic effect Effects 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 231100000357 carcinogen Toxicity 0.000 description 1
- 239000003183 carcinogenic agent Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000004134 energy conservation Methods 0.000 description 1
- 239000000835 fiber Substances 0.000 description 1
- 239000002803 fossil fuel Substances 0.000 description 1
- PLHJDBGFXBMTGZ-WEVVVXLNSA-N furazolidone Chemical compound O1C([N+](=O)[O-])=CC=C1\C=N\N1C(=O)OCC1 PLHJDBGFXBMTGZ-WEVVVXLNSA-N 0.000 description 1
- 229960001625 furazolidone Drugs 0.000 description 1
- 239000004519 grease Substances 0.000 description 1
- 239000005431 greenhouse gas Substances 0.000 description 1
- 239000011261 inert gas Substances 0.000 description 1
- 229910052744 lithium Inorganic materials 0.000 description 1
- 230000001050 lubricating effect Effects 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 229910001507 metal halide Inorganic materials 0.000 description 1
- 150000005309 metal halides Chemical class 0.000 description 1
- 239000003960 organic solvent Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical class [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 231100000331 toxic Toxicity 0.000 description 1
- 230000002588 toxic effect Effects 0.000 description 1
- 238000005809 transesterification reaction Methods 0.000 description 1
- 239000002912 waste gas Substances 0.000 description 1
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention discloses a device for preparing ethylene carbonate and a preparation method of ethylene carbonate, wherein the device comprises an EO absorption tower, a light component removal tower, an EC reactor and an EC refining tower which are sequentially connected in series; the device also comprises a decarbonization unit connected with the top of the EO absorption tower; the EO-containing recycle gas generated by the EO reactor is sent into an EO absorption tower, a part of crude EC generated by the EC reactor flows back into the EO absorption tower, and the other part of crude EC enters an EC refining tower; a part of refined EC obtained by the EC refining tower flows back into the EO absorption tower, and the other part of the refined EC is output from the production line; the crude EC and the refined EC which flow back into the EO absorption tower are used as EO absorption liquid, EO in the circulating gas is absorbed and then enters an EC reactor after passing through a light component removal tower; CO 2 produced by the decarbonization unit is fed into the EC reactor. The preparation method of the invention adopts low-concentration ethylene oxide for reaction from the viewpoint of production safety, and has the advantages of high safety, low energy consumption and low production cost.
Description
Technical Field
The invention relates to a device for preparing ethylene carbonate and a method for preparing ethylene carbonate by adopting the device.
Background
Ethylene Carbonate (EC) is an excellent organic solvent that can dissolve a variety of polymers. Can also be used as an organic intermediate to replace ethylene oxide for dioxygenation reaction, and is a main raw material for producing dimethyl carbonate by transesterification; can also be used as raw materials for synthesizing furazolidone, water glass series slurry, fiber finishing agent and the like; in addition, the method is also applied to lithium battery electrolyte. The ethylene carbonate can also be used as an active intermediate for producing lubricating oil and lubricating grease, and has wide application range.
Ethylene Oxide (EO) is a toxic carcinogen that is flammable and explosive and not easily transported over long distances, and therefore is strongly regional. Carbon dioxide (CO 2) is a rich and inexpensive carbon resource on earth, and is also a major greenhouse gas, which is mainly derived from the combustion emissions of fossil fuels. Today, where modern industry is rapidly developing, the emission of CO 2 to the atmosphere by humans is increasing at a rate of 4% per year, which is a rapid growth rate, which is a human knock alarm, but limiting CO 2 emissions to a large extent affects the development of modern industry and economy, so how to effectively utilize CO 2 is attracting great attention.
Ethylene oxide and carbon dioxide are used as raw materials to produce ethylene carbonate, and the method can fix CO 2 and plays a positive role in reducing greenhouse effect. Thus, such production methods that meet the concepts of "atomic economics" and "green chemistry" have been attracting attention. However, most of the existing process methods adopt high-concentration ethylene oxide (the purity is more than or equal to 99.9%) to react with carbon dioxide, and the production process has extremely high risk due to the inflammable and explosive chemical characteristics of EO. And the research on the EC production process of EO and CO 2 synthesis is mostly aimed at the research on catalysts and reactors in the reaction process, and the process flow is optimized from the aspect of intrinsic safety.
Disclosure of Invention
The invention aims to: the invention aims to provide a device for preparing ethylene carbonate, which has high safety and low energy consumption; it is another object of the present invention to provide a process for preparing ethylene carbonate using the above apparatus.
The technical scheme is as follows: the device for preparing ethylene carbonate comprises an EO absorption tower, a light component removing tower, an EC reactor and an EC refining tower which are sequentially connected in series; the device also comprises a decarbonization unit connected with the top of the EO absorption tower; the EO-containing recycle gas generated by the EO reactor is sent into an EO absorption tower, a part of crude EC generated by the EC reactor flows back into the EO absorption tower, and the other part of crude EC enters an EC refining tower; a part of refined EC obtained by the EC refining tower flows back into the EO absorption tower, and the other part of the refined EC is output from the production line; the crude EC and the refined EC which flow back into the EO absorption tower are used as EO absorption liquid, EO in the circulating gas is absorbed and then enters an EC reactor after passing through a light component removal tower; CO 2 produced by the decarbonization unit is fed into the EC reactor.
The EO absorption tower is a plate tower and is divided into four sections for absorption, the lower section is a decontamination section, water is used as a detergent to absorb byproducts formaldehyde and acetaldehyde in circulating gas so as to ensure the purity of absorption liquid in the middle section, the absorption process of the detergent is exothermic, absorption water in the decontamination section is pumped out and enters a circulating cooler for cooling, the cooled absorption water enters the lower section of the EO absorption tower for circulating absorption, and meanwhile, the absorption water is pumped out and discharged out of the pump so as to finish pollution discharge, and the discharged absorption water enters a waste alcohol recovery unit to recover waste alcohol; the middle section is a circulating EC absorption section, a stream of material is extracted from an outlet of an EC reactor and is used as circulating EC absorption liquid for absorption, and EO in circulating gas is absorbed; the middle-upper section is a refined EC absorption section, and adopts a stream of refined ethylene carbonate extracted from an EC refining tower as a lean absorption liquid to absorb, so that EO in the circulating gas is further absorbed; the rich absorption liquid after two sections of absorption is pumped up and enters a light component removing tower; removing light components such as methane, ethylene and the like in a light component removing tower through steam stripping; the upper section is a water washing section, absorbs a small amount of EC carried out in the circulating gas, and prevents the EC from entering the decarburization unit to influence the subsequent decarburization reaction. From the similar miscibility point of view, EC as an absorbent can absorb EO better, and four-stage absorption is more energy efficient. As the reaction proceeds, noncondensable gases in the circulating gas are accumulated continuously, and the discharge point of the noncondensable gases is the top of the light component removal tower.
Wherein the number of trays of the EO absorber is not more than 15. In the EO absorber of the traditional ethylene oxide/ethylene glycol production device, water is used as an absorbent, so that the same absorption effect is achieved (the representation of the absorption effect is simulated by Aspen and means the concentration of EO in the absorbent), and the theoretical plate number is far more than 15. Therefore, in the invention, the EO absorption tower adopts EC as absorption liquid, thereby greatly reducing equipment investment and achieving better absorption effect, namely, the concentration of EO in the absorption liquid is higher.
Wherein the decarbonization unit comprises a CO 2 absorption tower and a CO 2 desorption tower; after the EO-free recycle gas from the top of the EO absorber absorbs CO 2 in the CO 2 absorber by using hot potassium carbonate solution, the top gas is returned to the EO reaction unit, the potassium carbonate-rich solution generated in the tower bottom is sent to the CO 2 desorber to remove the absorbed CO 2, and the regenerated carbonate-lean solution is pumped back to the CO 2 absorber through the CO 2 desorber tower bottom; the gas phase at the top of the CO 2 desorber is sent to a cooler at the top of the CO 2 desorber, cooled and sent to a CO 2 emptying liquid separating tank; the liquid phase is sent to wastewater treatment, and the gas phase containing CO 2 is sent to an EC reactor for reaction.
The method for preparing the ethylene carbonate by adopting the device comprises the following steps:
(1) Contacting a portion of the crude EC produced by the EC reactor with EO-containing recycle gas from the EO reactor in an EO absorber as a recycle EC absorber and a portion of the purified EC produced by the EC purifier as a lean absorber, the absorber absorbing EO in the recycle gas;
(2) The EO-containing rich absorption liquid is pumped into an EC reactor after passing through a light component removal tower, and reacts with CO 2 generated by a decarbonization unit in the EC reactor to generate EC.
The method specifically comprises the following steps: the EO-containing circulating gas generated by the EO reactor enters an EO absorption tower, one stream of material discharged from the outlet of the EC reactor enters a subsequent EC refining tower, and the other stream of material is used as circulating EC absorption liquid to flow back into the EO absorption tower; one stream of refined EC produced by the EC refining tower is used as lean absorption liquid to flow back into the EO absorption tower, and the other stream is used as an EC product output production line; the EO in the circulating gas is absorbed by the circulating EC absorption liquid, the EO in the circulating gas is absorbed by the lean absorption liquid, and the rich absorption liquid after two-stage absorption is pumped up and enters the light component removal tower; the rich absorption liquid after the light component removal is pumped into an EC reactor after being cooled from the bottom of the light component removal tower; the rich absorption liquid reacts with CO 2 entering an EC reactor to generate EC, and crude EC generated by the EC reactor enters an EC refining tower to obtain refined EC; part of EO-free recycle gas discharged from the top of the EO absorption tower returns to the EO reactor to participate in the reaction, and the other part of EO-free recycle gas enters the decarbonization unit, and CO 2 separated by the decarbonization unit is mixed with external carbon dioxide and enters the EC reactor.
Wherein in step (1), the mass ratio of the circulating EC absorbing liquid to the lean absorbing liquid is 1:2 to 4, preferably the mass ratio of circulating EC absorption liquid to lean absorption liquid is 1:3. compared with the circulating EC absorption liquid, the absorption effect of the refined EC as the absorbent on EO is better, but the more the lean absorption liquid is, the higher the energy consumption is, so that the absorption effect on EO can be further increased by adopting a two-stage absorption mode, and the energy consumption can be effectively reduced on the one hand.
Wherein in step (2), the molar ratio of EC to EO in the EC reactor is from 6 to 9, preferably the molar ratio of EC to EO is 7. The EC content is effective to reduce the EO mass concentration in the EC reactor, i.e., to dilute the EO mass concentration. The EC reactor is a jacketed reactor, and the main reaction in the reactor is that ethylene oxide reacts with carbon dioxide to generate ethylene carbonate; in an EC reactor, too low or too high a molar ratio of EC to EO affects EO conversion; when the molar ratio of EC to EO is 7, the conversion rate of EO is 95%, and compared with the reaction in the EC reactor in the prior art by adopting pure EO, the mass concentration of EO in the EC reactor is 11% -14%, so that the production safety of the EC reactor can be effectively ensured, and the conversion rate of EO can be ensured to be about 95%.
In the preparation device, the EC refining tower comprises a controller and sensor equipment such as a temperature sensor, a flowmeter and the like which are connected with the controller; the controller comprises the following calculation modules:
calculation module X: q 1＝LR*{0.6*(TV-TL) +1}
Wherein L R is the mass flow of the external reflux measured by FT 3;
T V is the overhead gas phase temperature measured by TT 2;
t L is the liquid phase reflux temperature measured by TT 3;
the calculation module Y: q 2＝LR*{0.6*(TV-TL)+1}-LD
Wherein L D is the side offtake mass flow measured by FT 2;
Calculation module Z:
Wherein Q 2SP is the set value of Q 2;
The calculation module W: q 4＝Q1-Q3
The gas phase temperature T V at the top of the EC refining tower is measured by TT2, the liquid phase reflux temperature T L is measured by TT3, and the mass flow L R of external reflux is measured by FT 3. In the calculation module X, an output value Q 1 is obtained according to mass conservation and energy conservation, wherein Q 1 is required to meet the requirement that Q 1＝LR*{0.6*(TV-TL)+1}.Q1 is the side line product extraction quantity plus the internal reflux quantity. Conservation of mass: l c+LR＝LIR+LD,Lc is the amount of condensation, L R is the mass flow of the outer reflux, L IR is the mass flow of the inner reflux, and L D is the mass flow of the side draw.
FT2 is measured as the side offtake mass flow rate L D. In the calculation module Y, an output value Q 2 is obtained according to mass conservation, where Q 2 needs to satisfy Q 2＝LR*{0.6*(TV-TL)+1}-LD. Q2 is the measurement of internal reflux.
In the calculation module Z, given a set value Q 2SP of the calculation module, an output value Q 3 of the calculation module Z is calculated. Q3 is the output value of the inner reflux.
In the computing module W, according to the output value Q 1 of the computing module X and the output value Q 3 of the computing module Z, the output value Q 4 of the computing module W is obtained, where Q 4 needs to satisfy the requirement that Q 4＝Q1-Q3.Q4 is the product amount of side-draw.
The control scheme of the EC refining tower is to compensate the pressure fluctuation in the tower, so that the quality and purity of the product extracted from the side line are greatly improved. The slight pressure change in the tower will influence the relation between temperature and components, thus influence the product quality, the control scheme of the invention is differential control, realize the compensation to the pressure fluctuation through controlling the temperature difference (T V-TL), thus maintain the steady operation load of the tower, prevent the emergence of the flooding phenomenon, thus guarantee the product that the side line draws meets the product index, reach four nine standards.
The beneficial effects are that: compared with the prior art, the invention has the remarkable advantages that: the invention solves the problems of large equipment quantity, high energy consumption and high risk of the existing production process that the refined EO and CO 2 are required to react to generate EC, and the preparation method of the invention is used for producing the raw material ethylene oxide of ethylene carbonate, namely, the recycle gas generated by an EO reactor of an ethylene oxide/glycol device enters the EC reactor after passing through an EO absorption tower and a light component removal tower, and directly reacts with CO 2 to generate ethylene carbonate; in the process, no EO region with high concentration exists, so that the production method is optimized from the aspect of the process flow, and the production safety is improved; simultaneously, raw material carbon dioxide for producing ethylene carbonate comes from tail gas of a CO 2 emptying liquid separation tank in a decarbonization unit of an ethylene oxide/ethylene glycol device, so that self-production and self-sales of waste gas are realized, and waste materials are changed into valuable materials; the preparation method of the invention adopts low-concentration ethylene oxide for reaction from the viewpoint of production safety, thereby not only simplifying the equipment quantity, reducing the energy consumption of the device, but also greatly improving the production safety; has the advantages of high production safety, low energy consumption and low production cost.
Drawings
FIG. 1 is a schematic system diagram of an apparatus for producing ethylene carbonate according to the present invention.
Detailed Description
The technical scheme of the invention is further described below with reference to specific embodiments.
As shown in FIG. 1, the device for preparing ethylene carbonate comprises an EO absorption tower, a light component removing tower, an EC reactor and an EC refining tower which are sequentially connected in series; the device also comprises a decarbonization unit connected with the top of the EO absorption tower; the EO-containing recycle gas generated by the EO reactor is sent into an EO absorption tower, a part of crude EC generated by the EC reactor flows back into the EO absorption tower, and the other part of crude EC enters an EC refining tower; a part of refined EC obtained by the EC refining tower flows back into the EO absorption tower, and the other part of the refined EC is output from the production line; the crude EC and the refined EC which flow back into the EO absorption tower are used as EO absorption liquid, EO in the circulating gas is absorbed and then enters an EC reactor after passing through a light component removal tower; CO 2 produced by the decarbonization unit is fed into the EC reactor.
The decarbonization unit comprises a CO 2 absorption tower and a CO 2 desorption tower; after the EO-free recycle gas from the top of the EO absorber absorbs CO 2 in the CO 2 absorber by using hot potassium carbonate solution, the top gas is returned to the EO reaction unit, the potassium carbonate-rich solution generated in the tower bottom is sent to the CO 2 desorber to remove the absorbed CO 2, and the regenerated carbonate-lean solution is pumped back to the CO 2 absorber through the CO 2 desorber tower bottom; the gas phase at the top of the CO 2 desorber is sent to a cooler at the top of the CO 2 desorber, cooled and sent to a CO 2 emptying liquid separating tank; the liquid phase is sent to wastewater treatment, and the gas phase containing CO 2 is sent to an EC reactor for reaction.
In the ethylene oxide/glycol device, EO-containing circulating gas after passing through an EO reactor enters an EO absorption tower, one stream of material discharged from an outlet of the EC reactor enters a subsequent EC refining tower, and the other stream of material is used as circulating EC absorption liquid to flow back into the EO absorption tower; one stream of refined EC produced by the EC refining tower is used as lean absorption liquid to flow back into the EO absorption tower, and the other stream of refined EC is used as a product output production line of ethylene carbonate; the EO in the EO circulating gas is absorbed by the circulating EC absorption liquid, the EO in the circulating gas is absorbed by the lean absorption liquid, the rich absorption liquid after two sections of absorption is pumped up and enters a light component removal tower, and light components such as methane, ethylene and the like are removed in the light component removal tower through steam stripping; the rich absorption liquid after the light component removal is pumped into an EC reactor after being cooled from the bottom of the light component removal tower; the rich absorption liquid reacts with carbon dioxide entering the EC reactor to produce ethylene carbonate. And (3) returning one part of reaction products passing through the EC reactor as circulating EC absorption liquid to the middle section of the EO absorption tower, rectifying and separating the other part of reaction products into components such as diethylene glycol, triethylene glycol and the like in an EC refining tower, wherein the tower top product is water, carbon dioxide, light components such as monoethylene glycol and the like, and part of refined EC in the EC refining tower is cooled as lean absorption liquid by a cooler and then is fed into the middle-upper section of the EO absorption tower, so that the residual ethylene carbonate is taken as an electronic grade product, and the concentration of the product grade ethylene carbonate taken from a side line is more than 99.99wt%.
The invention relates to a method for preparing ethylene carbonate, the yield of which is 2 ten thousand tons/year, which comprises the following steps: the EO-containing recycle gas after passing through the EO reactor had a flow rate of 32532.23kg/hr, a pressure of 1561.33kPa, a temperature of 56℃and a EO content (in mass%) of 4.92%.
Introducing circulating sewage with flow rate of 20286.49kg/hr and temperature of 37.8deg.C into the lower section of EO absorption tower, absorbing by-product formaldehyde and acetaldehyde in circulating gas to ensure purity of absorption liquid (absorption liquid is circulating EC absorption liquid and lean EC absorption liquid) of absorption unit, discharging the corresponding absorption process of the sewage section to release heat, introducing the cooled water into cooler for cooling after pumping at 49.4deg.C, introducing the cooled water into the lower section of EO absorption tower for circulating absorption, discharging 217.11kg/hr of absorption water at pump outlet to complete sewage discharge, introducing the discharged absorption water into waste alcohol recovery unit, and recovering waste alcohol; the absorption unit is divided into a circulating EC absorption section and a refined EC absorption section. The circulating EC absorption section adopts crude EC product of 5050.41kg/hr unrefined at the outlet of the EC reactor to carry out EO absorption, and the refined EC absorption section adopts 17236.2kg/hr electronic grade EC product produced at the side line of the EC refining tower to carry out EO absorption; the temperature of the absorbed rich absorption liquid is 55.8 ℃, the rich absorption liquid is rich in 6.59 weight percent of EO and inert gas partially dissolved in the ethylene carbonate absorption liquid, and the absorbed rich absorption liquid enters a light component removing tower after being pumped up; the inlet flow rate of the light component removal tower is 23925.4kg/hr, the tower top pressure is 1000kPa, the tower top extraction amount is 45kg/hr, and the discharged gas at the tower top is a small amount of gas which is mainly dissolved in ethylene carbonate; the rich absorption liquid after the light component removal enters a cooler from the bottom of the light component removal tower to be cooled, the temperature of the cooled rich absorption liquid is 12 ℃, and the cooled rich absorption liquid is pumped into an EC reactor; the total flow rate of the carbon dioxide gas passing through the decarburization unit and the supplemented fresh carbon dioxide gas is 1725.62kg/hr, and the carbon dioxide gas and the cooled rich absorption liquid are sent into the EC reactor together for reaction.
The flow rate of the recycle gas for EO removal through the EO absorber was 30870.2kg/hr, and fed to the compressor for pressurization to 1931kPa.8113.63kg/hr of circulating gas is directly returned to the EO reactor to participate in the reaction, 22503.9kg/hr of circulating gas is preheated to 63.3 ℃ and then is sent to a CO 2 absorption tower to be absorbed by 18744.9kg/hr of carbonate solution at 62.2 ℃ to carry out CO 2. 18871.9kg/hr of the carbonate-rich solution having absorbed CO 2 was fed to the top of a CO 2 stripper, where the stripping produced 60 ℃,134.3kPa,316.324kg/hr CO 2 gas was mixed with 1409.3kg/hr fresh CO 2 as feed to the EC reactor, and 18744.9kg/hr of the carbonate-lean solution was stripped at the bottom.
The EC reactor is filled with a metal halide catalyst, a jacketed reactor is used, the operating temperature is set to 130 ℃, the operating pressure is set to 2801.33kPa, EO absorbed by ethylene carbonate is converted into ethylene carbonate, the reaction is exothermic, and the outlet temperature of the EO reactor is set to 95 ℃. The product flow through the EC reactor was 25606kg/hr. Cooling a part of the reaction product to 36 ℃, pumping the cooled part of the reaction product to a circulating EC absorption section (middle section) of an EO absorption tower for EO absorption, and pumping the rest EC product to an EC refining tower for rectifying and separating components such as diethylene glycol, triethylene glycol and the like; the top product of the EC refining tower is light component with boiling point lower than that of ethylene carbonate, the pressure of the top of the tower is 10kPa, the flow rate of the top product of the tower is 203.8kg/hr, the temperature is 63 ℃, 20345kg/hr of electronic grade ethylene carbonate is extracted from the side line of the EC refining tower, wherein 17236.2kg/hr of refined EC is cooled to 36 ℃ and then pumped to the fine EC absorption section (middle upper section) of the EO absorption tower for EO absorption.
Claims (6)
1. An apparatus for preparing ethylene carbonate, characterized in that: comprises an EO absorption tower, a light component removing tower, an EC reactor and an EC refining tower which are sequentially connected in series; the device also comprises a decarbonization unit connected with the top of the EO absorption tower; sending EO-containing recycle gas generated by the EO reactor into an EO absorption tower, wherein part of crude EC generated by the EC reactor flows back into the EO absorption tower, and the rest part of crude EC enters an EC refining tower; a part of refined EC obtained by the EC refining tower flows back into the EO absorption tower, and the rest is output from the production line; the crude EC and the refined EC which flow back into the EO absorption tower are used as EO absorption liquid, EO in the circulating gas is absorbed and then enters an EC reactor after passing through a light component removal tower; delivering CO 2 generated by the decarbonization unit into an EC reactor;
The EO absorption tower is a plate tower, and consists of four sections of absorption sections: the lower section of the washing agent is water, the middle section of the circulating EC absorption liquid is coarse EC, the middle section of the lean EC absorption liquid is refined EC, and the upper section of the absorption agent is water; the number of the tower plates of the EO absorption tower is not more than 15;
the decarbonization unit comprises a CO 2 absorption tower and a CO 2 desorption tower; after the EO-free recycle gas at the top of the EO absorption tower absorbs CO 2 in the CO 2 absorption tower, the top gas returns to the EO reaction unit, the rich absorbent generated at the tower bottom is sent to the CO 2 desorption tower to remove CO 2 absorbed by the absorbent, and the regenerated lean absorbent is pumped back to the CO 2 absorption tower through the CO 2 desorption tower bottom; the gas phase at the top of the CO 2 desorber is cooled and then sent to a CO 2 emptying liquid separation tank, and the gas phase containing CO 2 is mixed with external carbon dioxide and sent to an EC reactor.
2. A method of preparing ethylene carbonate using the apparatus of claim 1, comprising the steps of:
(1) Contacting a portion of the crude EC produced by the EC reactor with EO-containing recycle gas from the EO reactor in an EO absorber as a recycle EC absorber and a portion of the purified EC produced by the EC purifier as a lean absorber, the absorber absorbing EO in the recycle gas;
(2) The EO-containing rich absorption liquid is pumped into an EC reactor after passing through a light component removal tower, and reacts with CO 2 generated by a decarbonization unit in the EC reactor to generate EC.
3. The process for preparing ethylene carbonate according to claim 2, characterized in that it comprises in particular: the EO-containing circulating gas generated by the EO reactor enters an EO absorption tower, one stream of material discharged from the outlet of the EC reactor enters a subsequent EC refining tower, and the other stream of material is used as circulating EC absorption liquid to flow back into the EO absorption tower; one stream of refined EC produced by the EC refining tower is used as lean absorption liquid to flow back into the EO absorption tower, and the other stream is used as an EC product output production line; the EO in the circulating gas is absorbed by the circulating EC absorption liquid, the EO in the circulating gas is absorbed by the lean absorption liquid, and the rich absorption liquid after two-stage absorption is pumped up and enters the light component removal tower; the rich absorption liquid after the light component removal is pumped into an EC reactor after being cooled from the bottom of the light component removal tower; and (3) reacting the rich absorption liquid with CO 2 entering an EC reactor to generate EC, and entering the crude EC generated by the EC reactor into an EC refining tower to obtain refined EC.
4. A process for preparing ethylene carbonate according to claim 3, characterized in that: part of EO-free recycle gas discharged from the top of the EO absorption tower returns to the EO reactor to participate in the reaction, and the other part of EO-free recycle gas enters the decarbonization unit, and CO 2 separated by the decarbonization unit is mixed with external carbon dioxide and enters the EC reactor.
5. The method for producing ethylene carbonate according to claim 2, characterized in that: in step (1), the mass ratio of the circulating EC absorbing liquid to the lean absorbing liquid is 1: 2-4.
6. The method for producing ethylene carbonate according to claim 2, characterized in that: in the step (2), the molar ratio of EC to EO in the EC reactor is 6-9.
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Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101037424A (en) * | 2007-04-27 | 2007-09-19 | 中国石油化工股份有限公司 | Device and method for reducing temperature of poor-absorption liquid feed material of Ethylene Oxide absorption tower |
| CN106478583A (en) * | 2015-08-28 | 2017-03-08 | 中国石油化工股份有限公司 | The synthetic method of ethylene carbonate |
| CN106478586A (en) * | 2015-08-28 | 2017-03-08 | 中国石油化工股份有限公司 | The synthesis technique of ethylene carbonate |
| CN106608865A (en) * | 2015-10-21 | 2017-05-03 | 中国石油化工股份有限公司 | Energy-saving method for synthesizing ethylene carbonate |
| CN108467383A (en) * | 2018-06-04 | 2018-08-31 | 吕庆霖 | A kind of method of ethylene oxide device coproduction ethylene carbonate |
| CN111471033A (en) * | 2020-04-29 | 2020-07-31 | 中国科学院过程工程研究所 | Device and method for preparing cyclic carbonate by integrating absorption separation and catalytic reaction |
| CN112705124A (en) * | 2019-10-25 | 2021-04-27 | 中国石油化工股份有限公司 | Reactor, system for synthesizing carbonic ester and method for synthesizing carbonic ester |
-
2021
- 2021-08-30 CN CN202111001753.0A patent/CN115724819B/en active Active
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101037424A (en) * | 2007-04-27 | 2007-09-19 | 中国石油化工股份有限公司 | Device and method for reducing temperature of poor-absorption liquid feed material of Ethylene Oxide absorption tower |
| CN106478583A (en) * | 2015-08-28 | 2017-03-08 | 中国石油化工股份有限公司 | The synthetic method of ethylene carbonate |
| CN106478586A (en) * | 2015-08-28 | 2017-03-08 | 中国石油化工股份有限公司 | The synthesis technique of ethylene carbonate |
| CN106608865A (en) * | 2015-10-21 | 2017-05-03 | 中国石油化工股份有限公司 | Energy-saving method for synthesizing ethylene carbonate |
| CN108467383A (en) * | 2018-06-04 | 2018-08-31 | 吕庆霖 | A kind of method of ethylene oxide device coproduction ethylene carbonate |
| CN112705124A (en) * | 2019-10-25 | 2021-04-27 | 中国石油化工股份有限公司 | Reactor, system for synthesizing carbonic ester and method for synthesizing carbonic ester |
| CN111471033A (en) * | 2020-04-29 | 2020-07-31 | 中国科学院过程工程研究所 | Device and method for preparing cyclic carbonate by integrating absorption separation and catalytic reaction |
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