CN116265056A - Product separation refining device and method for preparing dimethyl carbonate by CO esterification - Google Patents
Product separation refining device and method for preparing dimethyl carbonate by CO esterification Download PDFInfo
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- IEJIGPNLZYLLBP-UHFFFAOYSA-N dimethyl carbonate Chemical compound COC(=O)OC IEJIGPNLZYLLBP-UHFFFAOYSA-N 0.000 title claims abstract description 406
- 238000000926 separation method Methods 0.000 title claims abstract description 194
- 230000032050 esterification Effects 0.000 title claims abstract description 51
- 238000005886 esterification reaction Methods 0.000 title claims abstract description 51
- 238000007670 refining Methods 0.000 title claims abstract description 42
- 238000000034 method Methods 0.000 title claims abstract description 38
- 239000002351 wastewater Substances 0.000 claims abstract description 36
- 238000011084 recovery Methods 0.000 claims abstract description 30
- 239000000463 material Substances 0.000 claims abstract description 20
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims description 154
- 238000000605 extraction Methods 0.000 claims description 38
- 239000007791 liquid phase Substances 0.000 claims description 12
- 238000001816 cooling Methods 0.000 claims description 9
- 238000000746 purification Methods 0.000 claims description 6
- 239000002131 composite material Substances 0.000 claims description 2
- 238000004064 recycling Methods 0.000 claims 1
- 238000005265 energy consumption Methods 0.000 abstract description 8
- CXHHBNMLPJOKQD-UHFFFAOYSA-M methyl carbonate Chemical compound COC([O-])=O CXHHBNMLPJOKQD-UHFFFAOYSA-M 0.000 abstract description 2
- 239000000047 product Substances 0.000 description 124
- TZIHFWKZFHZASV-UHFFFAOYSA-N methyl formate Chemical compound COC=O TZIHFWKZFHZASV-UHFFFAOYSA-N 0.000 description 76
- NKDDWNXOKDWJAK-UHFFFAOYSA-N dimethoxymethane Chemical compound COCOC NKDDWNXOKDWJAK-UHFFFAOYSA-N 0.000 description 59
- 239000007789 gas Substances 0.000 description 39
- 239000003054 catalyst Substances 0.000 description 11
- DNIAPMSPPWPWGF-UHFFFAOYSA-N Propylene glycol Chemical compound CC(O)CO DNIAPMSPPWPWGF-UHFFFAOYSA-N 0.000 description 10
- 238000006243 chemical reaction Methods 0.000 description 10
- 238000010992 reflux Methods 0.000 description 9
- 239000000203 mixture Substances 0.000 description 8
- LOMVENUNSWAXEN-UHFFFAOYSA-N Methyl oxalate Chemical compound COC(=O)C(=O)OC LOMVENUNSWAXEN-UHFFFAOYSA-N 0.000 description 7
- 238000011156 evaluation Methods 0.000 description 7
- 239000002994 raw material Substances 0.000 description 6
- 239000006227 byproduct Substances 0.000 description 5
- 238000009835 boiling Methods 0.000 description 4
- 238000006356 dehydrogenation reaction Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 229960004063 propylene glycol Drugs 0.000 description 4
- 235000013772 propylene glycol Nutrition 0.000 description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 3
- GOOHAUXETOMSMM-UHFFFAOYSA-N Propylene oxide Chemical compound CC1CO1 GOOHAUXETOMSMM-UHFFFAOYSA-N 0.000 description 3
- 238000010521 absorption reaction Methods 0.000 description 3
- 238000004458 analytical method Methods 0.000 description 3
- 239000007795 chemical reaction product Substances 0.000 description 3
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 description 2
- BZLVMXJERCGZMT-UHFFFAOYSA-N Methyl tert-butyl ether Chemical compound COC(C)(C)C BZLVMXJERCGZMT-UHFFFAOYSA-N 0.000 description 2
- 230000005540 biological transmission Effects 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 230000006315 carbonylation Effects 0.000 description 2
- 238000005810 carbonylation reaction Methods 0.000 description 2
- 239000000945 filler Substances 0.000 description 2
- 238000004817 gas chromatography Methods 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 239000012071 phase Substances 0.000 description 2
- RUOJZAUFBMNUDX-UHFFFAOYSA-N propylene carbonate Chemical compound CC1COC(=O)O1 RUOJZAUFBMNUDX-UHFFFAOYSA-N 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- DNIAPMSPPWPWGF-GSVOUGTGSA-N (R)-(-)-Propylene glycol Chemical compound C[C@@H](O)CO DNIAPMSPPWPWGF-GSVOUGTGSA-N 0.000 description 1
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 1
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- ZAMOUSCENKQFHK-UHFFFAOYSA-N Chlorine atom Chemical compound [Cl] ZAMOUSCENKQFHK-UHFFFAOYSA-N 0.000 description 1
- 229910021591 Copper(I) chloride Inorganic materials 0.000 description 1
- HBBGRARXTFLTSG-UHFFFAOYSA-N Lithium ion Chemical compound [Li+] HBBGRARXTFLTSG-UHFFFAOYSA-N 0.000 description 1
- YGYAWVDWMABLBF-UHFFFAOYSA-N Phosgene Chemical compound ClC(Cl)=O YGYAWVDWMABLBF-UHFFFAOYSA-N 0.000 description 1
- XSQUKJJJFZCRTK-UHFFFAOYSA-N Urea Chemical compound NC(N)=O XSQUKJJJFZCRTK-UHFFFAOYSA-N 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 239000004202 carbamide Substances 0.000 description 1
- SPFUWSBRIIKPOR-UHFFFAOYSA-N carbonyl dichloride;methanol Chemical compound OC.ClC(Cl)=O SPFUWSBRIIKPOR-UHFFFAOYSA-N 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 231100000481 chemical toxicant Toxicity 0.000 description 1
- 239000000460 chlorine Substances 0.000 description 1
- 229910052801 chlorine Inorganic materials 0.000 description 1
- OXBLHERUFWYNTN-UHFFFAOYSA-M copper(I) chloride Chemical compound [Cu]Cl OXBLHERUFWYNTN-UHFFFAOYSA-M 0.000 description 1
- 238000002425 crystallisation Methods 0.000 description 1
- 230000008025 crystallization Effects 0.000 description 1
- 230000007547 defect Effects 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 239000003814 drug Substances 0.000 description 1
- 239000003792 electrolyte Substances 0.000 description 1
- 238000004880 explosion Methods 0.000 description 1
- 239000002360 explosive Substances 0.000 description 1
- 239000003254 gasoline additive Substances 0.000 description 1
- 230000007062 hydrolysis Effects 0.000 description 1
- 238000006460 hydrolysis reaction Methods 0.000 description 1
- 239000002608 ionic liquid Substances 0.000 description 1
- 239000012948 isocyanate Substances 0.000 description 1
- 150000002513 isocyanates Chemical class 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 229910001416 lithium ion Inorganic materials 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- BLLFVUPNHCTMSV-UHFFFAOYSA-N methyl nitrite Chemical compound CON=O BLLFVUPNHCTMSV-UHFFFAOYSA-N 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000011943 nanocatalyst Substances 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 239000001301 oxygen Substances 0.000 description 1
- 229910052760 oxygen Inorganic materials 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 239000000575 pesticide Substances 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000000376 reactant Substances 0.000 description 1
- 230000008929 regeneration Effects 0.000 description 1
- 238000011069 regeneration method Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 230000001360 synchronised effect Effects 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 230000002194 synthesizing effect Effects 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
- 238000005809 transesterification reaction Methods 0.000 description 1
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Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D3/00—Distillation or related exchange processes in which liquids are contacted with gaseous media, e.g. stripping
- B01D3/14—Fractional distillation or use of a fractionation or rectification column
- B01D3/143—Fractional distillation or use of a fractionation or rectification column by two or more of a fractionation, separation or rectification step
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C68/00—Preparation of esters of carbonic or haloformic acids
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C68/00—Preparation of esters of carbonic or haloformic acids
- C07C68/08—Purification; Separation; Stabilisation
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- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)
Abstract
The invention discloses a product separation and refining device and method for preparing dimethyl carbonate by CO esterification. The device comprises a pre-separation tower, a DMC separation tower, a wastewater DMC recovery tower, a circulating gas separation tower, a DMM removal tower, an MF rectification tower, a DMM rectification tower, a pressurized DMC rectification tower and a normal pressure DMC rectification tower, wherein a methyl carbonate synthetic product feeding pipeline is connected with a pre-separation tower inlet, a pre-separation tower bottom outlet is connected with a wastewater DMC recovery tower inlet, a pre-separation tower lateral line outlet is connected with a DMC separation tower inlet, a pre-separation tower top outlet and a DMC separation tower top outlet are respectively connected with a circulating gas separation tower inlet, the circulating gas separation tower bottom is connected with a DMM removal inlet, and the DMM removal tower bottom is connected with a pressurized DMC rectification tower feeding port. The invention can be used for separating and refining dimethyl carbonate (DMC) product material flow, and has the characteristics of reasonable flow, low energy consumption and the like.
Description
Technical Field
The invention belongs to the technical field of chemical industry. In particular to a separation and refining device and a method of a reaction product system for preparing dimethyl carbonate by CO (carbon monoxide) esterification.
Background
Dimethyl carbonate (DMC) is a globally recognized green chemical, and is mainly used for producing Polycarbonate (PC), isocyanate, medicine and pesticide, and is used as a solvent for lithium ion battery electrolyte and paint, and is potentially used for replacing Methyl Tertiary Butyl Ether (MTBE) as a gasoline additive.
At present, 3 industrialized dimethyl carbonate synthesis technical routes exist, and 1 technical route with industrialized prospect:
(1) In the phosgene-methanol method, raw material phosgene is a highly toxic chemical, and byproduct HCl is highly corrosive, so that the route is eliminated.
(2) Transesterification process. According to the reactants, the industrialized technological route comprises:
(1) propylene oxide + CO2 + methanol → DMC + propylene glycol
The method has mild reaction condition and high yield. But the production raw material (propylene oxide) has high cost and the separation of the byproduct propylene glycol is difficult. In addition, the pollution of the raw material propylene oxide production process (chlorohydrination method) is large, the market of the byproduct propylene glycol is greatly excessive, and the sales are difficult.
(2) Urea+1, 2-propanediol- & gt propylene carbonate+liquid ammonia
Propylene carbonate + methanol → DMC + 1, 2-propanediol
The method has low yield and large equipment investment.
(3) Ethylene oxide+CO 2 +methanol→DMC+ethylene glycol
The invention provides a solid-supported ionic liquid catalyst in the process of Chinese academy of sciences, which has the advantages of high conversion per pass of ethylene oxide, strong raw material adaptability, no need of separation of the catalyst and the like, and realizes industrial demonstration application of mass production.
(3) Liquid phase methanol oxidation and carbonylation method
2CH 3 OH + CO + 0.5O 2 →DMC + H 2 O
The technical route has the defects that: the CuCl catalyst is unstable, short in service life and high in corrosiveness, and the catalyst regeneration circulation is difficult; the chlorine in the product affects the quality of the product; the byproducts are more; CO concentrations in oxygen are in the explosive limit range (12.5% -74%) and are prone to explosion.
(4) And (3) preparing dimethyl carbonate by CO esterification. The route catalyst adopts a supported metal nano catalyst, so that the space-time yield and the selectivity are both good; the reaction condition is mild, the pressure is low (0.2-0.5 MPag), the temperature is 100-150 ℃, and the method is a technical route with great industrial prospect.
The reaction principle of the preparation of the dimethyl carbonate by CO esterification is as follows:
CO+2CH 3 ONO → (CH 3 O) 2 CO+2NO
the raw materials are gaseous CO and methyl nitrite (CH) 3 ONO, abbreviated as MN), the main product is organic dimethyl carbonate, the byproducts are dimethyl oxalate (DMO), methyl Formate (MF), dimethoxymethane (DMM), methanol and the like, and the side reaction metering equation is as follows:
2CO＋2MN → DMO＋2NO
4MN → MF＋2CH3OH＋4NO
2MN+MeOH → DMM＋H 2 O
the boiling point of the dimethyl carbonate is 90 ℃, the melting point is 2-4 ℃, and the dimethyl carbonate is liquid at room temperature. Dimethyl oxalate has a boiling point of 174 ℃, a melting point of 54 ℃ and is solid at room temperature.
Chinese patent (CN 103901130B) discloses "an on-line evaluation device, an evaluation method and a production method of a catalyst for producing dimethyl carbonate". The evaluation device comprises a gas control pipeline system, a fixed bed reaction system, a product separation and purification system and an online gas chromatography analysis system, wherein the gas control pipeline system comprises three paths of gas control pipelines, and each path of gas control pipeline comprises a gas pipeline, a pressure stabilizing valve, a pressure gauge, a pressure stabilizing valve, a mass flow controller and a switching valve which are sequentially connected; the three gas pipelines are combined into one gas pipeline through the equal-diameter four-way joint, and a gas mixing box is arranged on the combined pipeline. The evaluation device can realize real-time synchronous analysis of all components of raw materials and products only by one online gas chromatography, has high analysis efficiency, accurate and reliable data and less investment, and can also efficiently produce, separate and purify the dimethyl carbonate.
The above patent provides a reaction route for preparing dimethyl carbonate (also called methyl formate by methanol carbonylation) by CO esterification, a catalyst evaluation method and a separation scheme suitable for laboratory scale and equipment, and does not provide a feasible engineering technical route suitable for industrialization.
Disclosure of Invention
The invention aims at providing a complete product separation and refining method and system which are suitable for industrialization aiming at a reaction system for preparing dimethyl carbonate by CO esterification, and has the characteristics of reasonable flow, low energy consumption and the like.
In order to achieve the aim of the invention, the invention provides a product separation and refining device and a product separation and refining method for preparing dimethyl carbonate (DMC) by CO esterification, and the specific technical scheme is as follows.
The invention provides a product separation and refining device for preparing dimethyl carbonate by CO esterification, which is characterized in that:
the device comprises a pre-separation tower, a DMC (dimethyl carbonate) separation tower, a wastewater DMC recovery tower, a circulating gas separation tower, a DMM (dimethoxy methane) removal tower, an MF (multi-frequency) rectification tower, a DMM rectification tower, a pressurized DMC rectification tower and an atmospheric DMC rectification tower, wherein a dimethyl carbonate synthetic product feeding pipeline is connected with an inlet of the pre-separation tower;
the pre-separation tower bottom outlet is connected with the wastewater DMC recovery tower inlet, the wastewater DMC recovery tower bottom is connected with a wastewater extraction pipeline, the pre-separation tower is provided with a side outlet, the pre-separation tower side outlet is connected with the DMC separation tower inlet, the pre-separation tower top outlet and the DMC separation tower top outlet are respectively connected with the circulating gas separation tower inlet, and the wastewater DMC recovery tower top outlet and the DMC separation tower bottom outlet are respectively connected with the DMC product extraction pipeline;
the outlet of the top of the circulating gas separation tower is connected with a circulating gas extraction pipeline, the outlet of the bottom of the circulating gas separation tower is connected with the inlet of a DMM removal tower, the upper outlet of the DMM removal tower is connected with the inlet of an MF rectifying tower, the outlet of the top of the MF rectifying tower is connected with an MF product extraction pipeline, the outlet of the bottom of the MF rectifying tower is connected with the inlet of the DMM rectifying tower, the outlet of the top of the DMM rectifying tower is connected with the DMM product extraction pipeline, the outlet of the bottom of the DMM rectifying tower is connected with an outlet pipeline for recovering methanol A, and the outlet of the bottom of the DMM removal tower is connected with the inlet of a pressurized DMC rectifying tower;
the top of the pressurized DMC rectifying tower is provided with a light component outlet, the outlet of the bottom of the pressurized DMC rectifying tower is connected with a DMC product extraction pipeline, a lateral line outlet is arranged on the lateral line of the pressurized DMC rectifying tower, the lateral line outlet is connected with the inlet of the normal pressure DMC rectifying tower, the upper outlet of the normal pressure DMC rectifying tower is connected with the inlet of the pressurized DMC rectifying tower, and the bottom of the normal pressure DMC rectifying tower is provided with a recovered methanol B outlet.
The product separation and refining device for preparing the dimethyl carbonate by CO esterification also comprises an electronic grade DMC heavy-removal tower and an electronic grade DMC light-removal tower, wherein a DMC product extraction pipeline is directly connected with a primary product DMC outlet pipeline, or the DMC product extraction pipeline is divided into two paths, one path is connected with the primary product DMC outlet pipeline, the other path is connected with an electronic grade DMC heavy-removal tower inlet, the electronic grade DMC heavy-removal tower top is connected with the electronic grade DMC light-removal tower inlet, the electronic grade DMC heavy-removal tower bottom is connected with a heavy component outlet pipeline, the electronic grade DMC light-removal tower top is connected with a pressurized DMC rectifying tower inlet, and the electronic grade DMC dehydrogenation tower bottom is connected with the electronic grade DMC outlet pipeline.
The product separation refining device for preparing dimethyl carbonate by CO esterification comprises a pre-separation tower, a DMC separation tower, a wastewater DMC recovery tower, a circulating gas separation tower, a DMM removal tower, an MF rectification tower, a DMM rectification tower, a pressurized DMC rectification tower, an atmospheric DMC rectification tower, an electronic grade DMC weight removal tower and an electronic grade DMC light removal tower which are all filler towers or plate towers or filler and plate type composite towers.
According to the invention, 90-150 theoretical plates are preferably arranged in the pre-separation tower, and the side extraction position of the pre-separation tower is 10-30 theoretical plates, preferably 15-25 theoretical plates, away from the top of the pre-separation tower; 30-50 theoretical plates, preferably 35-45 theoretical plates, are arranged in the DMC separation tower; 90-150 theoretical plates, preferably 110-130 theoretical plates, are arranged in the wastewater DMC recovery tower; 20-60 theoretical plates, preferably 25-45 theoretical plates, are arranged in the circulating gas separation tower; 35-65 theoretical plates, preferably 45-55 theoretical plates, are arranged in the DMM removal tower; 40-70 theoretical plates, preferably 50-65 theoretical plates, are arranged in the MF rectifying tower; 40-70 theoretical plates, preferably 50-65 theoretical plates, are arranged in the DMM rectifying tower; 60-100 theoretical plates, preferably 75-85 theoretical plates, are arranged in the pressurized DMC rectifying tower; 60-90 theoretical plates, preferably 65-80 theoretical plates, are arranged in the normal pressure DMC rectifying tower; 70-120 theoretical plates, preferably 85-110 theoretical plates, are arranged in the electronic-grade DMC weight removal tower; 30-50 theoretical plates, preferably 35-45 theoretical plates, are arranged in the electronic-grade DMC light-removal tower; and the lateral line extraction position of the pressurized DMC rectifying tower is positioned 5-20 theoretical plates, preferably 8-12 theoretical plates, away from the top of the pressurized DMC rectifying tower.
The invention provides a product separation and refining method for preparing dimethyl carbonate by CO esterification, which is characterized by comprising the following steps:
1) Cooling and condensing a product stream for preparing dimethyl carbonate by CO esterification, then, enabling the product stream to enter a pre-separation tower for pre-separation, and then, recombining and distributing the tower bottom separated by the pre-separation tower to a wastewater DMC recovery tower to remove wastewater to obtain DMC products, wherein a liquid phase side line separated by the pre-separation tower is extracted and sent to the DMC separation tower for separation, DMC products are obtained at the tower bottom after separation, a DMC separation tower top stream and a tower top stream separated by the pre-separation tower are respectively sent to a circulating gas separation tower, the tower top pressure of the pre-separation tower is 0.1-0.5 MPag, the tower top temperature is 30-70 ℃, and the tower bottom temperature is 120-170 ℃;
2) After removing heavy components, circulating gas is pumped out from the top of a circulating gas separation tower, heavy components at the bottom of the circulating gas separation tower enter a DMM removal tower, the material flow at the top of the DMM removal tower enters an MF rectifying tower for rectification to obtain an MF product, heavy material flow at the bottom of the MF rectifying tower enters a DMM rectifying tower for rectification to obtain a DMM product and recovered methanol A, and the heavy components at the bottom of the DMM removal tower enter a pressurized DMC rectifying tower;
3) The material flow entering the pressurized DMC rectifying tower is further rectified, the light component obtained after rectification of the pressurized DMC rectifying tower is discharged from the top of the pressurized DMC rectifying tower, the DMC product material flow obtained after rectification of the pressurized DMC rectifying tower is discharged from the bottom of the pressurized DMC rectifying tower, the mixed liquid phase material flow obtained after rectification of the pressurized DMC rectifying tower is discharged from the side line of the pressurized DMC rectifying tower, then the mixed liquid phase material flow enters the normal pressure DMC rectifying tower for rectification, the recovered methanol B is obtained from the bottom of the normal pressure DMC rectifying tower, and the material flow of the normal pressure DMC rectifying tower is returned to the pressurized DMC rectifying tower.
The invention relates to a product separation refining method for preparing dimethyl carbonate by CO esterification, which comprises the steps of taking DMC products obtained by a wastewater DMC recovery tower, DMC products obtained by a DMC separation tower and DMC products obtained by a pressurized DMC rectifying tower bottom as product external transmission, or taking part of the DMC products as product external transmission, and delivering the other part of the DMC products to an electronic grade DMC heavy removal tower, extracting heavy components from the electronic grade DMC heavy removal tower bottom, delivering an electronic grade DMC heavy removal tower top flow to an electronic grade DMC light removal tower, obtaining electronic grade DMC products from the electronic grade DMC light removal tower bottom, and returning an electronic grade DMC dehydrogenation tower top flow to the pressurized DMC rectifying tower.
According to the product separation and refining method for preparing the dimethyl carbonate by CO esterification, the temperature of the top of a DMC separation tower is 100-150 ℃, preferably 110-140 ℃, and the pressure of the top of the tower is 0.1-0.8 MPa, preferably 0.3-0.6 MPa; the bottom temperature is 145-170 ℃, preferably 150-165 ℃.
According to the product separation and refining method for preparing dimethyl carbonate by CO esterification, the pressure of the DMC recovery tower top of the wastewater is 0.05-0.12 MPa, preferably 0.75-0.10 MPa, and the temperature of the DMC recovery tower top is 95-135 ℃, preferably 100-130 ℃; the bottom temperature is 110-150 ℃, preferably 115-140 ℃.
According to the product separation and refining method for preparing dimethyl carbonate by CO esterification, the pressure of the top of the circulating gas separation tower is 0.08-0.4 MPa, preferably 0.1-0.3 MPa, and the temperature of the top of the tower is-50 to-20 ℃, preferably-40 to-25 ℃; the bottom temperature is 60-120 ℃, preferably 70-110 ℃.
According to the product separation and refining method for preparing dimethyl carbonate by CO esterification, the pressure of the top of the DMM removing tower is 0.07-0.2 MPa, preferably 0.08-0.13 MPa, the temperature of the top of the tower is 35-75 ℃, preferably 40-65 ℃, and the temperature of the bottom of the tower is 70-110 ℃, preferably 80-100 ℃.
According to the product separation and refining method for preparing dimethyl carbonate by CO esterification, the pressure of the top of the MF rectifying tower is 0.07-0.2 MPa, preferably 0.08-0.13 MPa, and the temperature of the top of the tower is 35-70 ℃, preferably 40-60 ℃; the bottom temperature is 50-85 ℃, preferably 55-80 ℃.
According to the product separation and refining method for preparing dimethyl carbonate by CO esterification, the pressure of the top of the DMM rectifying tower is 0.06-0.14 MPa, preferably 0.07-0.13 MPa, and the temperature of the top of the tower is 35-70 ℃, preferably 40-60 ℃; the bottom temperature is 50-85 ℃, preferably 55-80 ℃.
According to the product separation and refining method for preparing dimethyl carbonate by CO esterification, the pressure of the top of the pressurized DMC rectifying tower is 1.0-1.5 MPa, preferably 1.1-1.3 MPa, and the temperature of the top of the tower is 120-160 ℃, preferably 130-150 ℃; the bottom temperature is 170-210 ℃, preferably 185-200 ℃.
According to the product separation and refining method for preparing dimethyl carbonate by CO esterification, the pressure of the top of the normal pressure DMC rectifying tower is 0.06-0.15 MPa, preferably 0.0-0.10 MPa, and the temperature of the top of the tower is 65-90 ℃, preferably 70-85 ℃; the bottom temperature is 70-100 ℃, preferably 75-95 ℃.
According to the product separation and refining method for preparing dimethyl carbonate by CO esterification, the pressure of the top of the electronic-grade DMC heavy-removal tower is 0.06-0.15 MPa, preferably 0.07-0.10 MPa, and the temperature of the top of the tower is 95-120 ℃, preferably 100-115 ℃; the bottom temperature is 105-140 ℃, preferably 110-130 ℃.
According to the product separation and refining method for preparing dimethyl carbonate by CO esterification, the pressure of the top of the electronic-grade DMC light-removal tower is 0.06-0.15 MPa, preferably 0.07-0.10 MPa, and the temperature of the top of the tower is 80-120 ℃, preferably 90-115 ℃; the bottom temperature is 105-140 ℃, preferably 110-130 ℃.
The bottom product flow from the DMM removal tower and the top product flow from the pressurized DMC rectifying tower are DMC methanol mixture, DMC can be respectively fed into different positions of the pressurized DMC rectifying tower according to the DMC concentration contained in the DMC mixture, the bottom product flow of the pressurized DMC rectifying tower is DMC product, the side extract flow of the pressurized DMC rectifying tower is DMC-methanol azeotrope under the pressurized condition, and trace light components (noncondensable gas) are discharged from the top of the pressurized DMC rectifying tower. DMC-methanol azeotrope extracted from the lateral line of the upper part of the pressurized DMC rectifying tower enters the normal pressure DMC rectifying tower. The bottom of the normal pressure DMC rectifying tower is a methanol product, and can be recycled in the device. The top material flow of the normal pressure DMC rectifying tower is DMC-methanol mixture, and the mixture is sent to the feeding port of the pressurized DMC rectifying tower.
The invention can be used for separating and refining dimethyl carbonate product flow, and is mainly used for separating and refining products of preparing dimethyl carbonate by CO esterification.
Compared with the prior art, the product separation and refining device and method for preparing the dimethyl carbonate by CO esterification have the beneficial effects that:
(1) Aiming at a reaction system for preparing the dimethyl carbonate by CO esterification, the invention provides a complete product separation and refining method and system which are suitable for industrialization, and the method and the system have the characteristics of reasonable flow, low energy consumption and the like.
(2) The invention is provided with the pre-separation tower and the DMC light-removal tower, can pre-separate 70-90% of DMC yield, reduces DMC treatment capacity in subsequent processes, and especially has extremely high energy consumption for DMC-methanol system (azeotrope exists) separation, thereby greatly saving energy consumption. The bottom product of the pre-separation tower is subjected to heavy component removal through the DMC heavy component removal tower, so that a primary product DMC can be obtained, in addition, the bottom product of the DMC light component removal tower is also the primary product DMC, and the primary product DMC obtained by adding the two components accounts for about 80-95% of the total amount.
(3) The invention adopts the main products (MF, DMC, methanol, DMM) in the medium-cooling separation recycle gas. Compared with the conventional methanol absorption technical route, the methanol absorption agent is avoided, so that only a small amount of methanol generated by the reaction in the product separation system is reacted, and the flow entering the DMC-methanol separation part is greatly reduced. Because DMC-methanol separation energy consumption is extremely high, energy consumption can be saved by a wide margin.
(4) The invention adopts the main products (MF, DMC, methanol, DMM) in the medium-cooling separation recycle gas. Compared with the conventional methanol absorption technical route, the concentration of the feed DMC entering the DMC-methanol separation part is greatly improved, the concentration exceeds the normal pressure DMC-methanol azeotrope, and the energy required by DMC concentration of the normal pressure DMC rectifying tower is saved, so that the energy consumption of the DMC-methanol separation part is further reduced.
The invention will now be described in further detail with reference to the drawings and the detailed description, without limiting the scope of the invention.
Drawings
FIG. 1 is a schematic diagram of a product separation and refining device for preparing methyl formate by CO esterification.
The reference numerals shown in the figures are:
1-synthetic product feed line, 2-pre-separation column, 3-DMC separation column, 4-wastewater DMC recovery column, 5-recycle gas separation column, 6-DMM removal column, 7-MF rectification column, 8-DMM rectification column, 9-pressurized DMC rectification column, 10-normal pressure DMC rectification column, 11-electronic grade DMC de-heavies column, 12-electronic grade DMC light ends removal column, 13-wastewater extraction line, 14-DMC product extraction line, 15-first grade DMC outlet line, 16-recycle gas extraction line, 17-MF product extraction line, 18-DMM product extraction line, 19-recovered methanol A outlet line, 20-recovered methanol B outlet line, 21-heavy fraction outlet line, 22-electronic grade DMC outlet line.
As shown in figure 1, the product separation and refining device for preparing dimethyl carbonate by CO esterification comprises a pre-separation tower 2, a DMC (dimethyl carbonate) separation tower 3, a wastewater DMC recovery tower 4, a circulating gas separation tower 5, a DMM (dimethoxy methane) removal tower 6, an MF rectifying tower 7, a DMM rectifying tower 8, a pressurized DMC rectifying tower 9 and an atmospheric DMC rectifying tower 10, wherein a methyl carbonate synthetic product feeding pipeline 1 is connected with an inlet of the pre-separation tower 2;
the bottom outlet of the pre-separation tower 2 is connected with the inlet of the wastewater DMC recovery tower 4, the bottom of the wastewater DMC recovery tower is connected with a wastewater extraction pipeline 13, the pre-separation tower 2 is provided with a side outlet, the side outlet of the pre-separation tower 2 is connected with the inlet of the DMC separation tower 3, the top outlet of the pre-separation tower and the top outlet of the DMC separation tower are respectively connected with the inlet of the recycle gas separation tower 5, and the top outlet of the wastewater DMC recovery tower and the bottom outlet of the DMC separation tower are respectively connected with a DMC product extraction pipeline 14;
the outlet of the top of the circulating gas separation tower is connected with a circulating gas extraction pipeline 16, the outlet of the bottom of the circulating gas separation tower is connected with the inlet of a DMM removal tower 6, the upper outlet of the DMM removal tower 6 is connected with the inlet of an MF rectifying tower 7, the outlet of the top of the MF rectifying tower is connected with an MF product extraction pipeline 17, the outlet of the bottom of the MF rectifying tower is connected with the inlet of a DMM rectifying tower 8, the outlet of the top of the DMM rectifying tower is connected with a DMM product extraction pipeline 18, the outlet of the bottom of the DMM rectifying tower is connected with a recovered methanol A outlet pipeline 19, and the outlet of the bottom of the DMM removal tower is connected with the inlet of a pressurized DMC rectifying tower 9;
the top of the pressurized DMC rectifying tower is provided with a light component outlet, the bottom of the pressurized DMC rectifying tower is connected with a DMC product extraction pipeline 14, a lateral line of the pressurized DMC rectifying tower 9 is provided with a lateral line outlet, the lateral line outlet is connected with the inlet of the normal pressure DMC rectifying tower 10, the upper outlet of the normal pressure DMC rectifying tower 10 is connected with the inlet of the pressurized DMC rectifying tower 9, the bottom of the normal pressure DMC rectifying tower is provided with a recovered methanol B outlet, and the recovered methanol B outlet is connected with a recovered methanol B outlet pipeline.
As shown in figure 1, the product separation and refining device for preparing dimethyl carbonate by CO esterification further comprises an electronic-grade DMC heavy-removal tower 11 and an electronic-grade DMC light-removal tower 12, wherein a DMC product extraction pipeline 14 is directly connected with a primary-grade DMC outlet pipeline 15, or the DMC product extraction pipeline 14 is divided into two paths, one path is connected with the primary-grade DMC outlet pipeline 15, the other path is connected with the inlet of the electronic-grade DMC heavy-removal tower 11, the electronic-grade DMC heavy-removal tower top is connected with the inlet of the electronic-grade DMC light-removal tower 12, the electronic-grade DMC heavy-removal tower bottom is connected with a heavy-component outlet pipeline 21, the electronic-grade DMC light-removal tower top is connected with the inlet of the pressurized DMC rectifying tower 9, and the electronic-grade DMC dehydrogenation tower bottom is connected with an electronic-grade DMC outlet pipeline 22.
In the present invention, unless otherwise specified, the rectifying column in the apparatus of the present invention means a rectifying column system comprising a rectifying column body and attached equipment such as a bottom reboiler, a bottom product transfer pump, a top condenser, a top reflux drum, a top reflux and a product transfer pump.
CO esterification to synthesize dimethyl carbonate.
Under the conditions of 110-150 ℃ and 0.1-0.6 MPag, the following reaction occurs under the action of a catalyst:
CO＋2CH 3 ONO (MN) → C 3 H 6 O 3 (DMC)＋2NO
2CO＋2CH 3 ONO (MN) → C 4 H 6 O 4 (DMO)＋2NO
2CO+H 2 +2CH 3 ONO (MN) → 2HCOOCH 3 (MF) +2NO
2MN+MeOH → DMM＋H 2 O＋2NO
4MN → MF＋2CH 3 OH＋4NO
the catalyst used for synthesizing the dimethyl carbonate by CO esterification is not limited, and the catalyst and the evaluation method disclosed in Chinese patent CN103901130B are preferably adopted.
According to the preferred catalyst and evaluation method, the reactor outlet gas phase composition is as follows:
DMC：12~20%、MF：1~3%、DMM：1~4%、DMO：0.01~0.1%、MeOH：1~3%、MN+NO：20~32%、CO：1~3%、N 2 and other components: 40-60%.
The operation method of the product separation and refining device for preparing the dimethyl carbonate by CO esterification is simple as follows:
1) Cooling and condensing a product stream for preparing dimethyl carbonate by CO esterification, then, enabling the product stream to enter a pre-separation tower 2 for pre-separation, and re-distributing the product stream separated by the pre-separation tower 2 to a wastewater DMC recovery tower 4 for recovering DMC products in wastewater, wherein a liquid phase lateral line separated by the pre-separation tower is extracted and sent to a DMC separation tower 3 for separation, DMC products are obtained at the bottom of the DMC separation tower after separation, a DMC separation tower top stream and a tower top stream separated by the pre-separation tower 2 are respectively sent to a circulating gas separation tower 5, the tower top pressure of the pre-separation tower 2 is 0.1-0.5 MPag, the tower top temperature is 30-70 ℃, and the tower bottom temperature is 120-170 ℃;
2) After the flow entering the circulating gas separation tower 5 is subjected to weight removal, circulating gas is pumped out from the top of the circulating gas separation tower, heavy components at the bottom of the circulating gas separation tower enter a DMM removal tower 6, the flow at the top of the DMM removal tower enters an MF rectifying tower 7 to be rectified to obtain an MF product, the MF product is discharged through an MF product pumping pipeline 17, heavy flow at the bottom of the MF rectifying tower enters a DMM rectifying tower 8 to be rectified to obtain a DMM product and recovered methanol A, the DMM product is discharged through a DMM product pumping pipeline 18, the recovered methanol A is discharged through a recovered methanol A outlet pipeline 19, and heavy components at the bottom of the DMM removal tower enter a pressurized DMC rectifying tower 9;
3) The material flow entering the pressurized DMC rectifying tower 9 is further rectified, the light component obtained after rectification of the pressurized DMC rectifying tower 9 is discharged from the top of the pressurized DMC rectifying tower, the DMC product material flow obtained after rectification of the pressurized DMC rectifying tower 9 is discharged from the bottom of the pressurized DMC rectifying tower, the mixed liquid phase material flow obtained after rectification of the pressurized DMC rectifying tower 9 is discharged from the side line of the pressurized DMC rectifying tower 9, then enters the normal pressure DMC rectifying tower 10 for rectification, the recovered methanol B is obtained from the bottom of the normal pressure DMC rectifying tower, the recovered methanol B is discharged from the outlet pipeline 20 of the recovered methanol B, and the material flow of the normal pressure DMC rectifying tower is returned to the pressurized DMC rectifying tower 9.
The DMC product obtained from the wastewater DMC recovery tower 4, the DMC product obtained from the DMC separation tower 3 and the DMC product obtained from the bottom of the pressurized DMC rectifying tower 9 in FIG. 1 can be taken as product external output through DMC product extraction pipeline 14 or one part of the DMC product is taken as product external output, the other part of the DMC product is sent to an electronic grade DMC heavy-removal tower 11, heavy components at the bottom of the electronic grade DMC heavy-removal tower are extracted through a heavy component outlet pipeline 21, the electronic grade DMC heavy-removal tower top is sent to an electronic grade DMC light-removal tower 12, the electronic grade DMC product is obtained from the bottom of the electronic grade DMC light-removal tower, the electronic grade DMC product is sent out through an electronic grade DMC product outlet pipeline 22, and the electronic grade DMC dehydrogenation tower top stream returns to the pressurized DMC rectifying tower 9.
And cooling and condensing the product stream of the dimethyl carbonate prepared by CO esterification to 55-80 ℃ and then entering a pre-separation tower 2 for pre-separation, wherein a heat exchanger is preferably adopted for cooling and condensing, and the cooling and condensing exchanges heat with a proper stream (for example, a stream entering a reactor).
The main function of the pre-separation column 2 is to separate the heavy components (H) 2 O, DMO, etc.), a high-concentration DMC and methanol mixture is sidewise withdrawn. The preseparation column is a rectifying column with side offtake, typically provided with a bottom reboiler, a liquid phase side offtake, an overhead condenser and a reflux drum.
The circulating gas separation column 5 has the functions of: the main products (MF, DMC, methanol, DMM) are separated from the reaction product recycle gas, and the overhead gas phase may be returned to the esterification unit.
The DMC-methanol separation part has the main functions of separating DMC from methanol, and can adopt the technical routes of pressure-variable rectification, extraction rectification, constant boiling rectification and the like. The DMC-methanol separation section includes a pressurized DMC rectifying column 9 and an atmospheric DMC rectifying column 10.
The main function of the DMM removal column 6 is to separate the reaction products, with MF and DMM as the main components at the top and DMC and methanol as the main components at the bottom. The DMM removal tower 6 is a rectifying tower, a reboiler is arranged at the bottom of the rectifying tower, and a condenser and a reflux tank are arranged at the top of the rectifying tower.
The main function of the DMC separation column 3 is to separate the liquid-phase offtake side of the pre-separation column 2 into light components and DMC product. The DMC light-removing tower 3 is a rectifying tower, a reboiler is arranged at the bottom of the rectifying tower, and a condenser and a reflux tank are arranged at the top of the rectifying tower. The liquid phase extraction side line from the pre-separation tower 2 enters the DMC light-removal tower 3, DMC, methanol and other light components are taken as the top product, DMC products (more than or equal to 99.5%) are taken as the bottom product, and the product can be used as the output of the product or can be sent to the electronic grade DMC refining part, and finally is used as the output of the electronic grade DMC.
The main function of MF rectifying column 7 is to separate the feed into an overhead MF product, a bottom DMM and methanol mixture. The MF rectifying tower 7 is a rectifying tower, a reboiler is arranged at the bottom of the rectifying tower, and a condenser and a reflux tank are arranged at the top of the rectifying tower.
The tower top product from the DMM removal tower 6 enters an MF rectifying tower 7, and the tower top product is an MF superior product (more than or equal to 96 percent), can be directly used as a product, and can also be sent to a hydrolysis unit; the bottom product is a mixture of DMM and methanol and is fed to the feed inlet of DMM rectifying column 14.
The DMM rectifying column 8 mainly serves to separate the feed into the overhead DMM product, methanol at the bottom. The DMM rectifying tower 8 is a rectifying tower, a reboiler is arranged at the bottom of the rectifying tower, and a condenser and a reflux tank are arranged at the top of the rectifying tower.
The top product of the DMM rectifying tower 8 is DMM (which is divided into three product specifications according to the concentration of 85%, 90% and 99%), and is directly used as the product for output; the bottom product is methanol flow and can be recycled.
The DMC-methanol separation part has the main functions of separating DMC from methanol, and can adopt the technical routes of pressure-variable rectification, extraction rectification, constant boiling rectification and the like. The DMC-methanol separation section includes an atmospheric DMC rectifying column 10 and a pressurized DMC rectifying column 9.
The normal pressure DMC rectifying tower 10 and the pressurized DMC rectifying tower 9 are rectifying towers, and each tower is provided with a reboiler, a tower top condenser and a reflux tank.
The main function of the electronic grade DMC refining part is to refine DMC (more than or equal to 99.5%) to obtain electronic grade DMC (more than or equal to 99.99%). Common technical routes include crystallization, rectification, etc., and the rectification method is preferred in the present invention.
The electronic grade DMC refining part comprises an electronic grade DMC heavy-removing tower 11 and an electronic grade DMC light-removing tower 12 which are rectifying towers, and each tower is provided with a reboiler, a tower top condenser and a reflux tank.
Claims (11)
1. A product separation refining device for preparing dimethyl carbonate by CO esterification is characterized in that: the device comprises a pre-separation tower, a DMC separation tower, a wastewater DMC recovery tower, a circulating gas separation tower, a DMM removal tower, an MF rectification tower, a DMM rectification tower, a pressurized DMC rectification tower and an atmospheric DMC rectification tower, wherein a dimethyl carbonate synthetic product feeding pipeline is connected with an inlet of the pre-separation tower;
the pre-separation tower bottom outlet is connected with the wastewater DMC recovery tower inlet, the wastewater DMC recovery tower bottom outlet is connected with a wastewater extraction pipeline, the pre-separation tower is provided with a side outlet, the pre-separation tower side outlet is connected with the DMC separation tower inlet, the pre-separation tower top outlet and the DMC separation tower top outlet are respectively connected with the circulating gas separation tower inlet, and the wastewater DMC recovery tower top outlet and the DMC separation tower bottom outlet are respectively connected with the DMC product extraction pipeline;
the outlet of the top of the circulating gas separation tower is connected with a circulating gas extraction pipeline, the outlet of the bottom of the circulating gas separation tower is connected with the inlet of a DMM removal tower, the upper outlet of the DMM removal tower is connected with the inlet of an MF rectifying tower, the outlet of the top of the MF rectifying tower is connected with an MF product extraction pipeline, the outlet of the bottom of the MF rectifying tower is connected with the inlet of the DMM rectifying tower, the outlet of the top of the DMM rectifying tower is connected with the DMM product extraction pipeline, the outlet of the bottom of the DMM rectifying tower is connected with an outlet pipeline for recovering methanol A, and the outlet of the bottom of the DMM removal tower is connected with the inlet of a pressurized DMC rectifying tower;
the top of the pressurized DMC rectifying tower is provided with a light component outlet, the outlet of the bottom of the pressurized DMC rectifying tower is connected with a DMC product extraction pipeline, a lateral line outlet is arranged on the lateral line of the pressurized DMC rectifying tower, the lateral line outlet is connected with the inlet of the normal pressure DMC rectifying tower, the upper outlet of the normal pressure DMC rectifying tower is connected with the inlet of the pressurized DMC rectifying tower, and the bottom of the normal pressure DMC rectifying tower is provided with a recovered methanol B outlet.
2. The product separation and purification device for preparing dimethyl carbonate by CO esterification according to claim 1, which is characterized in that: the product separation refining device for preparing the dimethyl carbonate by CO esterification further comprises an electronic grade DMC heavy removal tower and an electronic grade DMC light removal tower, wherein a DMC product extraction pipeline is connected with a primary product DMC outlet pipeline, or the DMC product extraction pipeline is divided into two paths, one path is connected with the primary product DMC outlet pipeline, the other path is connected with an electronic grade DMC heavy removal tower inlet, the electronic grade DMC heavy removal tower top is connected with an electronic grade DMC light removal tower inlet, the electronic grade DMC heavy removal tower bottom is connected with a heavy component outlet pipeline, the electronic grade DMC light removal tower top is connected with a pressurized DMC rectifying tower inlet, and the electronic grade DMC light removal tower bottom is connected with an electronic grade DMC outlet pipeline.
3. The product separation and purification device for preparing dimethyl carbonate by CO esterification according to claim 1 or 2, which is characterized in that: the pre-separation tower, the DMC separation tower, the wastewater DMC recovery tower, the circulating gas separation tower, the DMM removal tower, the MF rectification tower, the DMM rectification tower, the pressurized DMC rectification tower, the normal pressure DMC rectification tower, the electronic grade DMC heavy removal tower and the electronic grade DMC light removal tower are all filled towers, or plate type towers, or filled and plate type composite towers.
4. The product separation and purification device for preparing dimethyl carbonate by CO esterification according to claim 3, wherein the product separation and purification device is characterized in that: 90-150 theoretical plates are arranged in the pre-separation tower, the side line extraction position of the pre-separation tower is located at a distance of 10-30 theoretical plates from the pre-separation tower top, 30-50 theoretical plates are arranged in the DMC separation tower, 90-150 theoretical plates are arranged in the wastewater DMC recovery tower, 20-60 theoretical plates are arranged in the circulating gas separation tower, 35-65 theoretical plates are arranged in the DMM stripping tower, 40-70 theoretical plates are arranged in the MF rectifying tower, 40-70 theoretical plates are arranged in the DMM rectifying tower, 60-100 theoretical plates are arranged in the pressurized DMC rectifying tower, 60-90 theoretical plates are arranged in the normal pressure DMC stripping tower, 70-120 theoretical plates are arranged in the electronic grade DMC stripping tower, 30-50 theoretical plates are arranged in the pressurized DMC rectifying tower, and 5-20 theoretical plates are located at a distance of the pressurized DMC rectifying tower top.
5. The product separation and purification device for preparing dimethyl carbonate by CO esterification according to claim 4, which is characterized in that: the pre-separation tower side line extraction position is located 15-25 theoretical plates away from the pre-separation tower top, 35-45 theoretical plates are arranged in the DMC separation tower, 110-130 theoretical plates are arranged in the wastewater DMC recovery tower, 25-45 theoretical plates are arranged in the circulating gas separation tower, 45-55 theoretical plates are arranged in the DMM stripping tower, 50-65 theoretical plates are arranged in the MF rectifying tower, 50-65 theoretical plates are arranged in the DMM rectifying tower, 75-85 theoretical plates are arranged in the pressurized DMC rectifying tower, 65-80 theoretical plates are arranged in the normal pressure DMC rectifying tower, 85-110 theoretical plates are arranged in the electronic grade DMC stripping tower, 35-45 theoretical plates are arranged in the electronic grade DMC stripping tower side line, and 8-12 theoretical plates away from the pressurized DMC rectifying tower top are located at the pressurized DMC rectifying tower top extraction position.
6. The method of the product separation and refining device for preparing the dimethyl carbonate by CO esterification is characterized by comprising the following steps:
1) Cooling and condensing a product stream for preparing dimethyl carbonate by CO esterification, then enabling the product stream to enter a pre-separation tower for pre-separation, and re-distributing the product stream to the bottom of the pre-separation tower for recycling DMC products in wastewater by a wastewater DMC recovery tower, wherein a liquid phase side line separated by the pre-separation tower is extracted and sent to the DMC separation tower for separation, DMC products are obtained at the bottom of the DMC separation tower after separation, a DMC separation tower top stream and a tower top stream separated by the pre-separation tower are respectively sent to a circulating gas separation tower, the tower top pressure of the pre-separation tower is 0.1-0.5 MPag, the tower top temperature is 30-70 ℃, and the tower bottom temperature is 120-170 ℃;
2) After removing heavy components, circulating gas is pumped out from the top of a circulating gas separation tower, heavy components at the bottom of the circulating gas separation tower enter a DMM removal tower, the material flow at the top of the DMM removal tower enters an MF rectifying tower for rectification to obtain an MF product, heavy material flow at the bottom of the MF rectifying tower enters a DMM rectifying tower for rectification to obtain a DMM product and recovered methanol A, and the heavy components at the bottom of the DMM removal tower enter a pressurized DMC rectifying tower;
3) The material flow entering the pressurized DMC rectifying tower is further rectified, the light component obtained after rectification of the pressurized DMC rectifying tower is discharged from the top of the pressurized DMC rectifying tower, the DMC product material flow obtained after rectification of the pressurized DMC rectifying tower is discharged from the bottom of the pressurized DMC rectifying tower, the mixed liquid phase material flow obtained after rectification of the pressurized DMC rectifying tower is discharged from the side line of the pressurized DMC rectifying tower, then the mixed liquid phase material flow enters the normal pressure DMC rectifying tower for rectification, the recovered methanol B is obtained from the bottom of the normal pressure DMC rectifying tower, and the material flow of the normal pressure DMC rectifying tower is returned to the pressurized DMC rectifying tower.
7. The method for separating and refining the product of preparing the dimethyl carbonate by CO esterification according to claim 6, which is characterized by comprising the following steps: the DMC product obtained by the wastewater DMC recovery tower, the DMC product obtained by the DMC separation tower and the DMC product obtained by the pressurized DMC rectifying tower bottom are used as the product external transportation or part of the DMC product is used as the product external transportation, the other part of the DMC product is sent to the electronic grade DMC heavy-removal tower, the heavy components at the electronic grade DMC heavy-removal tower bottom are extracted, the electronic grade DMC heavy-removal tower top flow is sent to the electronic grade DMC light-removal tower, the electronic grade DMC product is obtained at the electronic grade DMC light-removal tower bottom, and the electronic grade DMC light-removal tower top flow returns to the pressurized DMC rectifying tower.
8. The method for separating and refining the product of preparing the dimethyl carbonate by CO esterification according to claim 6 or 7, which is characterized by comprising the following steps: the temperature of the DMC separation tower top is 100-150 ℃, the pressure of the DMC separation tower top is 0.1-0.8 MPa, and the temperature of the DMC separation tower bottom is 145-170 ℃; the pressure of the DMC recovery tower top of the wastewater is 0.05-0.12 MPa, the temperature of the tower top is 95-135 ℃, and the temperature of the tower bottom is 110-150 ℃; the pressure of the top of the circulating gas separation tower is 0.08-0.4 MPa, the temperature of the top of the tower is-50 to-20 ℃, and the temperature of the bottom of the tower is 60-120 ℃; the pressure of the top of the DMM removing tower is 0.07-0.2 MPa, the temperature of the top of the tower is 35-75 ℃, and the temperature of the bottom of the tower is 70-110 ℃; the pressure of the MF rectifying tower top is 0.07-0.2 MPa, the temperature of the tower top is 35-70 ℃, and the temperature of the tower bottom is 50-85 ℃; the pressure of the top of the DMM rectifying tower is 0.06-0.14 MPa, the temperature of the top of the tower is 35-70 ℃, and the temperature of the bottom of the tower is 50-85 ℃; the pressure of the top of the pressurized DMC rectifying tower is 1.0-1.5 MPa, the temperature of the top of the tower is 120-160 ℃, and the temperature of the bottom of the tower is 170-210 ℃; the pressure of the top of the normal pressure DMC rectifying tower is 0.06-0.15 MPa, the temperature of the top of the tower is 65-90 ℃, and the temperature of the bottom of the tower is 70-100 ℃; the pressure of the top of the electronic-grade DMC heavy removal tower is 0.06-0.15 MPa, the temperature of the top of the tower is 95-120 ℃, and the temperature of the bottom of the tower is 105-140 ℃; the pressure of the top of the electronic-grade DMC light-removal tower is 0.06-0.15 MPa, the temperature of the top of the tower is 80-120 ℃, and the temperature of the bottom of the tower is 105-140 ℃.
9. The method for separating and refining the product of preparing the dimethyl carbonate by CO esterification, which is characterized by comprising the following steps of: the temperature of the DMC separation tower top is 110-140 ℃, the pressure of the DMC separation tower top is 0.3-0.6 MPa, and the temperature of the DMC separation tower bottom is 150-165 ℃; the pressure of the DMC recovery tower top of the wastewater is 0.75-0.10 MPa, the temperature of the tower top is 100-130 ℃, and the temperature of the tower bottom is 115-140 ℃; the pressure of the top of the circulating gas separation tower is 0.1-0.3 MPa, the temperature of the top of the tower is-40 to-25 ℃, and the temperature of the bottom of the tower is 70-110 ℃; the pressure of the top of the DMM removing tower is 0.08-0.13 MPa, the temperature of the top of the tower is 40-65 ℃, and the temperature of the bottom of the tower is 80-100 ℃; the pressure of the MF rectifying tower top is 0.08-0.13 MPa, the temperature of the tower top is 40-60 ℃, and the temperature of the tower bottom is 55-80 ℃; the pressure of the top of the DMM rectifying tower is 0.07-0.13 MPa, the temperature of the top of the tower is 40-60 ℃, and the temperature of the bottom of the tower is 55-80 ℃; the pressure of the top of the pressurized DMC rectifying tower is 1.1-1.3 MPa, the temperature of the top of the tower is 130-150 ℃, and the temperature of the bottom of the tower is 185-200 ℃; the pressure of the top of the normal pressure DMC rectifying tower is 0.0-0.10 MPa, the temperature of the top of the tower is 70-85 ℃, and the temperature of the bottom of the tower is 75-95 ℃; the pressure of the top of the electronic-grade DMC heavy removal tower is 0.07-0.10 MPa, the temperature of the top of the tower is 100-115 ℃, and the temperature of the bottom of the tower is 110-130 ℃; the pressure of the top of the electronic-grade DMC light-removing tower is 0.07-0.10 MPa, the temperature of the top of the tower is 90-115 ℃, and the temperature of the bottom of the tower is 110-130 ℃.
10. The method for separating and refining the product of preparing the dimethyl carbonate by CO esterification according to claim 9, which is characterized by comprising the following steps: and cooling and condensing the product stream of the dimethyl carbonate prepared by CO esterification to 55-80 ℃ and then entering a pre-separation tower for pre-separation.
11. The method for separating and refining the product of preparing the dimethyl carbonate by CO esterification according to claim 1, which is characterized by comprising the following steps: the bottom product stream from the DMM removal and the top product stream from the pressurized DMC rectifier enter different locations of the pressurized DMC rectifier, respectively, depending on the DMC concentration contained therein.
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| CN116531789A (en) * | 2023-07-06 | 2023-08-04 | 山东海科新源材料科技股份有限公司 | Purification device and method for dimethyl carbonate |
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| CN116531789A (en) * | 2023-07-06 | 2023-08-04 | 山东海科新源材料科技股份有限公司 | Purification device and method for dimethyl carbonate |
| CN116531789B (en) * | 2023-07-06 | 2023-09-19 | 山东海科新源材料科技股份有限公司 | Purification method of dimethyl carbonate |
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