JPH0676205B2 - High-purity carbon dioxide recovery method - Google Patents
High-purity carbon dioxide recovery methodInfo
- Publication number
- JPH0676205B2 JPH0676205B2 JP62001822A JP182287A JPH0676205B2 JP H0676205 B2 JPH0676205 B2 JP H0676205B2 JP 62001822 A JP62001822 A JP 62001822A JP 182287 A JP182287 A JP 182287A JP H0676205 B2 JPH0676205 B2 JP H0676205B2
- Authority
- JP
- Japan
- Prior art keywords
- ethylene oxide
- tower
- gas
- carbon dioxide
- conduit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 title claims description 262
- 239000001569 carbon dioxide Substances 0.000 title claims description 131
- 229910002092 carbon dioxide Inorganic materials 0.000 title claims description 131
- 238000000034 method Methods 0.000 title claims description 45
- 238000011084 recovery Methods 0.000 title 1
- IAYPIBMASNFSPL-UHFFFAOYSA-N Ethylene oxide Chemical compound C1CO1 IAYPIBMASNFSPL-UHFFFAOYSA-N 0.000 claims description 270
- 239000007788 liquid Substances 0.000 claims description 126
- 238000010521 absorption reaction Methods 0.000 claims description 119
- 239000007789 gas Substances 0.000 claims description 102
- 238000000926 separation method Methods 0.000 claims description 51
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 claims description 48
- 239000005977 Ethylene Substances 0.000 claims description 48
- 230000018044 dehydration Effects 0.000 claims description 38
- 238000006297 dehydration reaction Methods 0.000 claims description 38
- 238000010438 heat treatment Methods 0.000 claims description 32
- 238000007254 oxidation reaction Methods 0.000 claims description 30
- 239000007795 chemical reaction product Substances 0.000 claims description 23
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 claims description 20
- 229910001882 dioxygen Inorganic materials 0.000 claims description 20
- 230000003647 oxidation Effects 0.000 claims description 20
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 claims description 13
- 239000003054 catalyst Substances 0.000 claims description 13
- 230000003197 catalytic effect Effects 0.000 claims description 13
- 229910052709 silver Inorganic materials 0.000 claims description 13
- 239000004332 silver Substances 0.000 claims description 13
- 239000012071 phase Substances 0.000 claims description 11
- 239000012808 vapor phase Substances 0.000 claims description 7
- 238000005194 fractionation Methods 0.000 claims description 4
- LYCAIKOWRPUZTN-UHFFFAOYSA-N ethylene glycol Natural products OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 49
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 41
- QTBSBXVTEAMEQO-UHFFFAOYSA-N Acetic acid Chemical compound CC(O)=O QTBSBXVTEAMEQO-UHFFFAOYSA-N 0.000 description 39
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 34
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 32
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 28
- 238000009792 diffusion process Methods 0.000 description 24
- 239000012535 impurity Substances 0.000 description 23
- 238000009835 boiling Methods 0.000 description 21
- 238000006243 chemical reaction Methods 0.000 description 17
- IKHGUXGNUITLKF-UHFFFAOYSA-N Acetaldehyde Chemical compound CC=O IKHGUXGNUITLKF-UHFFFAOYSA-N 0.000 description 16
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 16
- 239000011261 inert gas Substances 0.000 description 16
- 229910052757 nitrogen Inorganic materials 0.000 description 16
- WSFSSNUMVMOOMR-UHFFFAOYSA-N Formaldehyde Chemical compound O=C WSFSSNUMVMOOMR-UHFFFAOYSA-N 0.000 description 15
- 229910052786 argon Inorganic materials 0.000 description 14
- 239000000498 cooling water Substances 0.000 description 14
- UBAZGMLMVVQSCD-UHFFFAOYSA-N carbon dioxide;molecular oxygen Chemical compound O=O.O=C=O UBAZGMLMVVQSCD-UHFFFAOYSA-N 0.000 description 9
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 8
- 239000001301 oxygen Substances 0.000 description 8
- 229910052760 oxygen Inorganic materials 0.000 description 8
- 239000002518 antifoaming agent Substances 0.000 description 7
- 239000006227 byproduct Substances 0.000 description 7
- 238000004519 manufacturing process Methods 0.000 description 7
- 238000010992 reflux Methods 0.000 description 7
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 6
- 239000007864 aqueous solution Substances 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- BWHMMNNQKKPAPP-UHFFFAOYSA-L potassium carbonate Chemical compound [K+].[K+].[O-]C([O-])=O BWHMMNNQKKPAPP-UHFFFAOYSA-L 0.000 description 6
- 239000000047 product Substances 0.000 description 6
- 239000000243 solution Substances 0.000 description 6
- IKHGUXGNUITLKF-XPULMUKRSA-N acetaldehyde Chemical compound [14CH]([14CH3])=O IKHGUXGNUITLKF-XPULMUKRSA-N 0.000 description 5
- 125000002485 formyl group Chemical class [H]C(*)=O 0.000 description 5
- 230000002378 acidificating effect Effects 0.000 description 4
- 239000012267 brine Substances 0.000 description 4
- 239000013065 commercial product Substances 0.000 description 4
- 239000013505 freshwater Substances 0.000 description 4
- 238000006460 hydrolysis reaction Methods 0.000 description 4
- WSFSSNUMVMOOMR-NJFSPNSNSA-N methanone Chemical compound O=[14CH2] WSFSSNUMVMOOMR-NJFSPNSNSA-N 0.000 description 4
- 230000001590 oxidative effect Effects 0.000 description 4
- 238000012856 packing Methods 0.000 description 4
- 238000007086 side reaction Methods 0.000 description 4
- HPALAKNZSZLMCH-UHFFFAOYSA-M sodium;chloride;hydrate Chemical compound O.[Na+].[Cl-] HPALAKNZSZLMCH-UHFFFAOYSA-M 0.000 description 4
- 239000000126 substance Substances 0.000 description 4
- 239000002250 absorbent Substances 0.000 description 3
- 230000002745 absorbent Effects 0.000 description 3
- 238000001816 cooling Methods 0.000 description 3
- 239000003085 diluting agent Substances 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- VUZPPFZMUPKLLV-UHFFFAOYSA-N methane;hydrate Chemical compound C.O VUZPPFZMUPKLLV-UHFFFAOYSA-N 0.000 description 3
- 229910000027 potassium carbonate Inorganic materials 0.000 description 3
- 235000011181 potassium carbonates Nutrition 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- 239000012670 alkaline solution Substances 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 238000003795 desorption Methods 0.000 description 2
- 238000011010 flushing procedure Methods 0.000 description 2
- -1 glycol ethers Chemical class 0.000 description 2
- 238000007670 refining Methods 0.000 description 2
- HZAXFHJVJLSVMW-UHFFFAOYSA-N 2-Aminoethan-1-ol Chemical compound NCCO HZAXFHJVJLSVMW-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-L Carbonate Chemical compound [O-]C([O-])=O BVKZGUZCCUSVTD-UHFFFAOYSA-L 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- 241001494479 Pecora Species 0.000 description 1
- ZLMJMSJWJFRBEC-UHFFFAOYSA-N Potassium Chemical compound [K] ZLMJMSJWJFRBEC-UHFFFAOYSA-N 0.000 description 1
- UIIMBOGNXHQVGW-DEQYMQKBSA-M Sodium bicarbonate-14C Chemical compound [Na+].O[14C]([O-])=O UIIMBOGNXHQVGW-DEQYMQKBSA-M 0.000 description 1
- GSEJCLTVZPLZKY-UHFFFAOYSA-N Triethanolamine Chemical compound OCCN(CCO)CCO GSEJCLTVZPLZKY-UHFFFAOYSA-N 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- 150000001340 alkali metals Chemical class 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- ZBCBWPMODOFKDW-UHFFFAOYSA-N diethanolamine Chemical compound OCCNCCO ZBCBWPMODOFKDW-UHFFFAOYSA-N 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 229930195733 hydrocarbon Natural products 0.000 description 1
- 150000002430 hydrocarbons Chemical class 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 229910052700 potassium Inorganic materials 0.000 description 1
- 239000011591 potassium Substances 0.000 description 1
- 239000011736 potassium bicarbonate Substances 0.000 description 1
- 229910000028 potassium bicarbonate Inorganic materials 0.000 description 1
- 235000015497 potassium bicarbonate Nutrition 0.000 description 1
- TYJJADVDDVDEDZ-UHFFFAOYSA-M potassium hydrogencarbonate Chemical compound [K+].OC([O-])=O TYJJADVDDVDEDZ-UHFFFAOYSA-M 0.000 description 1
- 235000011118 potassium hydroxide Nutrition 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 229910052708 sodium Inorganic materials 0.000 description 1
- 239000011734 sodium Substances 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 235000017550 sodium carbonate Nutrition 0.000 description 1
- 235000011121 sodium hydroxide Nutrition 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02A—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE
- Y02A50/00—TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE in human health protection, e.g. against extreme weather
- Y02A50/20—Air quality improvement or preservation, e.g. vehicle emission control or emission reduction by using catalytic converters
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02C—CAPTURE, STORAGE, SEQUESTRATION OR DISPOSAL OF GREENHOUSE GASES [GHG]
- Y02C20/00—Capture or disposal of greenhouse gases
- Y02C20/40—Capture or disposal of greenhouse gases of CO2
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/151—Reduction of greenhouse gas [GHG] emissions, e.g. CO2
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P20/00—Technologies relating to chemical industry
- Y02P20/50—Improvements relating to the production of bulk chemicals
Landscapes
- Carbon And Carbon Compounds (AREA)
- Epoxy Compounds (AREA)
- Gas Separation By Absorption (AREA)
Description
【発明の詳細な説明】 （産業上の利用分野） 本発明は、エチレンオキシド製造プロセスから高純度二
酸化炭素を回収する方法に関するものである。TECHNICAL FIELD The present invention relates to a method for recovering high-purity carbon dioxide from an ethylene oxide production process.
詳しくは二酸化炭素吸収塔で二酸化炭素含有ガスをアル
カリ性溶液と接触せしめて二酸化炭素を吸収し、二酸化
炭素放散塔で二酸化炭素含有アルカリ性溶液を加熱して
二酸化炭素を放散せしめる工程から得られた放散二酸化
炭素含有ガスの熱エネルギーを回収し、高純度二酸化炭
素を回収する方法に関する。さらに詳しくはエチレンを
分子状酸素源として酸素を用いて、銀触媒の存在下、接
触気相酸化してエチレンオキシドを製造するいわゆるエ
チレンの酸素酸化法において、エチレンと分子状酸素と
の副反応で生成する二酸化炭素を含有するガスから高純
度二酸化炭素を製造する方法に関する。エチレンを銀接
触の存在下、分子状酸素含有ガスと接触気相酸化して生
成したエチレンオキシドを含有する反応生成ガスをエチ
レンオキシド吸収塔へ導入し吸収液と向流接触させ、エ
チレンオキシド吸収塔頂部よりのガスはエチレン酸化反
応工程へ循環し、エチレンオキシドを含むエチレンオキ
シド吸収塔底液はエチレンオキシド放散塔へ供給し、エ
チレンオキシド放散塔頂からエチレンオキシドを放散せ
しめ、エチレンオキシドおよび水を含む留出物を凝縮さ
せ、未凝縮ガスは脱水塔へ供給し、脱水塔で水分を分離
し、軽質分分離塔で軽質分を分離し、ついでエチレンオ
キシド精留塔でエチレンオキシドを精留する工程におい
て、軽質分分離塔の加熱エネルギーを低減させるエチレ
ンオキシドの精製方法および二酸化炭素の回収方法に関
するものである。Specifically, in the carbon dioxide absorption tower, the carbon dioxide-containing gas is brought into contact with the alkaline solution to absorb the carbon dioxide, and in the carbon dioxide diffusion tower, the carbon dioxide-containing alkaline solution is heated to dissipate the carbon dioxide. The present invention relates to a method for recovering thermal energy of a carbon-containing gas and recovering high-purity carbon dioxide. More specifically, in a so-called oxygen oxidation method of ethylene in which ethylene is used as a molecular oxygen source to produce ethylene oxide by catalytic gas phase oxidation in the presence of a silver catalyst, it is produced by a side reaction between ethylene and molecular oxygen. And a method for producing high-purity carbon dioxide from a gas containing carbon dioxide. In the presence of silver contact with ethylene, a reaction product gas containing ethylene oxide produced by catalytic gas-phase oxidation with a molecular oxygen-containing gas is introduced into an ethylene oxide absorption tower and is brought into countercurrent contact with the absorbing liquid, and the ethylene oxide absorption tower top The gas is circulated to the ethylene oxidation reaction step, the bottom liquid of the ethylene oxide absorption tower containing ethylene oxide is supplied to the ethylene oxide diffusion tower, ethylene oxide is diffused from the top of the ethylene oxide diffusion tower, and the distillate containing ethylene oxide and water is condensed and uncondensed. Gas is supplied to the dehydration tower, water is separated in the dehydration tower, light components are separated in the light fraction separation column, and then ethylene oxide rectification tower is used to rectify ethylene oxide. To a method for purifying ethylene oxide and a method for recovering carbon dioxide It is intended.
（従来の技術） エチレンオキシドは一般につぎのようにして精製され
る。エチレンと分子状酸素含有ガスとを銀触媒上で接触
気相酸化いて生成するエチレンオキシドを含む反応生成
ガスをエチレンオキシド吸収塔へ導びき水を主とする吸
収液と向流接触させるエチレンオキシド水溶液として回
収し、ついでエチレンオキシド放散塔へ送りエチレンオ
キシド放散塔底部を加熱蒸気で加熱することによってエ
チレンオキシドを水溶液から放散させ、エチレンオキシ
ド放散塔底部より、実質的にエチレンオキシドを含まな
い水溶液は吸収液として循環使用し、エチレンオキシド
放散塔頂部より放散されるエチレンオキシド、水、二酸
化炭素、不活性ガス（窒素、アルゴン、メタン、エタ
ン、）の他ホルムアルデヒド等の低沸点不純物およびア
セトアルデヒド、酢酸等の高沸点不純物を含む放散物を
脱水工程、軽質分分離工程および重質分分離工程の各々
を経て精製しエチレンオキシドを製造することができ
る。(Prior Art) Ethylene oxide is generally purified as follows. A reaction product gas containing ethylene oxide produced by catalytic vapor-phase oxidation of ethylene and a molecular oxygen-containing gas on a silver catalyst is introduced to an ethylene oxide absorption tower and recovered as an aqueous solution of ethylene oxide which is brought into countercurrent contact with an absorption liquid mainly composed of water. Then, the ethylene oxide is sent from the aqueous solution to the ethylene oxide stripping tower by heating the bottom of the ethylene oxide stripping tower with heating steam, and the aqueous solution containing substantially no ethylene oxide is circulated from the bottom of the ethylene oxide stripping tower as an absorption liquid to disperse the ethylene oxide. Dehydration process of emission products containing ethylene oxide, water, carbon dioxide, inert gases (nitrogen, argon, methane, ethane, etc.) emitted from the top of the tower, as well as low-boiling impurities such as formaldehyde and high-boiling impurities such as acetaldehyde and acetic acid. , Light separation And purified over each of the heavies separation step can be produced ethylene oxide.
つぎにエチレンオキシドの製造プロセスにおいて、循環
ガス中から高純度の二酸化炭素を製造する方法について
説明する。Next, a method for producing high-purity carbon dioxide from the circulating gas in the ethylene oxide production process will be described.
エチレンと分子状酸素とを銀系触媒上で反応せしめる
と、 C2H4＋1/202→C2H4O ……（１） で示される主反応でエチレンオキシドが生成し、このほ
かに、 C2H4＋302→２CO2+2H2O ……（２） で示される副反応により二酸化炭素および水が生成する
ことが知られている。そしてエチレンを分子状酸素によ
り銀触媒の存在下、接触気相酸化してエチレンオキシド
を製造する方法において、エチレンオキシドの収率を高
めるため、エチレンの反応率を小さくし、前記反応式
（１）で示される主反応が起る方法、すなわちエチレン
の反応率を小さく、エチレンオキシドの選択率を大きく
する方法が採用され、未反応エチレンは反応帯へ再循環
されているのが一般的である。When ethylene and molecular oxygen are reacted on a silver-based catalyst, ethylene oxide is produced in the main reaction shown by C 2 H 4 +1/20 2 → C 2 H 4 O (1), and in addition to this, It is known that carbon dioxide and water are produced by the side reaction represented by C 2 H 4 +30 2 → 2CO 2 + 2H 2 O (2). In the method of producing ethylene oxide by catalytic vapor-phase oxidation of ethylene with molecular oxygen in the presence of a silver catalyst, the reaction rate of ethylene is reduced to increase the yield of ethylene oxide, and the reaction is represented by the above reaction formula (1). The main reaction that occurs is a method in which the reaction rate of ethylene is low and the selectivity of ethylene oxide is high is adopted, and unreacted ethylene is generally recycled to the reaction zone.
このような未反応エチレンを反応帯へ循環させる方法に
おいて、前記反応式（１）で生成する主反応生成物のエ
チレンオキシドおよび反応式（２）で生成する副反応生
成物の二酸化炭素、水並びに循環工程中に多分に導入さ
れる希釈ガス（メタン、エタン、窒素、炭酸ガス）の不
活性ガスを分離しなければ、一定ガス組成で反応を遂行
することが不可能に陥いる。In such a method of circulating unreacted ethylene to the reaction zone, carbon dioxide, water and circulation of ethylene oxide as the main reaction product produced by the reaction formula (1) and carbon dioxide as a side reaction product produced by the reaction formula (2) Unless the inert gas of the diluent gas (methane, ethane, nitrogen, carbon dioxide) that is mostly introduced during the process is separated, it becomes impossible to carry out the reaction with a constant gas composition.
この反応生成ガス流からエチレンオキシド、二酸化炭
素、水並びに不活性ガスを分離する方法として、次のエ
チレンの空気酸化法特公昭46-24004号公報およびエチレ
ンの空気酸化法特公昭38-19103号公報、特公昭38-21063
号公報、特公昭44-30244号公報の代表的なプロセスが知
られている。As a method for separating ethylene oxide, carbon dioxide, water and an inert gas from this reaction product gas stream, the following ethylene air oxidation method JP-B-46-24004 and ethylene air oxidation method JP-B-38-19103, Japanese Examined Japanese Patent Publication 38-21063
Representative processes of Japanese Patent Publication No. 44-30244 and Japanese Patent Publication No. 44-30244 are known.
エチレンを分子状酸素により銀触媒の存在下、接触気相
酸化して、エチレンオキシドを製造する方法において、
分子状酸素の供給源として、酸素を用いるエチレンの酸
素酸化法においては、エチレンオキシドを含む反応生成
ガスをエチレンオキシド吸収塔に導びき水を主とする吸
収液と向流接触させ反応生成ガス中のエチレンオキシド
を吸収液に吸収せしめて回収し、吸収液と吸収されなか
った未反応のエチレン、酸素および二酸化炭素、窒素、
アルゴン、メタン、エタン等からなる希釈ガスから、エ
チレンと分子状酸素との副反応で生成した二酸化炭素を
分離した後、反応帯へ、リサイクルし、そして反応に使
用されたエチレンおよび酸素ならびに反応帯と吸収工程
とのプロセスでわずかに漏出したガス分を補充すること
により反応原料ガス組成を調整し反応に共することであ
る。In the method for producing ethylene oxide by catalytic gas phase oxidation of ethylene with molecular oxygen in the presence of a silver catalyst,
In the oxygen oxidation method of ethylene using oxygen as a supply source of molecular oxygen, a reaction product gas containing ethylene oxide is introduced into an ethylene oxide absorption tower and is brought into countercurrent contact with an absorption liquid mainly composed of water to cause ethylene oxide in the reaction product gas. Absorbed and collected in an absorbing solution, unreacted ethylene, oxygen and carbon dioxide, nitrogen, which was not absorbed with the absorbing solution,
After separating carbon dioxide produced by the side reaction of ethylene and molecular oxygen from a diluent gas consisting of argon, methane, ethane, etc., it is recycled to the reaction zone, and the ethylene and oxygen used in the reaction and the reaction zone It is to adjust the composition of the reaction raw material gas and cooperate with the reaction by replenishing a slightly leaked gas in the processes of the absorption step and the absorption step.
従来、前記酸素法における二酸化炭素の分離法として、
エチレンオキシド吸収塔頂よりのガスの一部は反応帯へ
リサイクルし、残部を二酸化炭素ガス吸収塔へ導き、ア
ルカリ性吸収液たとえば熱炭酸カリ水溶液と向流接触さ
せて二酸化炭素ガスをアルカリ性吸収液に吸収せしめ、
ついで二酸化炭素ガスを含有するアルカリ性吸収液を二
酸化炭素ガス放散塔へ導き、二酸化炭素ガス放散塔底部
を加熱することにより二酸化炭素ガスを放散分離し、二
酸化炭素ガス放散塔頂より実質的に二酸化炭素を放散分
離した炭酸カリ水溶液は再び二酸化炭素吸収塔の吸収液
として使用する方法が採用されている。Conventionally, as a method for separating carbon dioxide in the oxygen method,
Part of the gas from the top of the ethylene oxide absorption tower is recycled to the reaction zone, the rest is led to the carbon dioxide gas absorption tower, and the carbon dioxide gas is absorbed by the alkaline absorption liquid such as hot potassium carbonate aqueous solution in countercurrent contact. Sir,
Then, an alkaline absorption liquid containing carbon dioxide gas is introduced into a carbon dioxide gas diffusion tower, carbon dioxide gas is diffused and separated by heating the bottom part of the carbon dioxide gas diffusion tower, and substantially carbon dioxide is emitted from the top of the carbon dioxide gas diffusion tower. The method of using the aqueous solution of potassium carbonate, which has been separated by diffusion, as the absorbing solution for the carbon dioxide absorption tower is adopted again.
（発明が解決しようとする問題点） しかしながら、このようなエチレンオキシドの精製方法
は軽質分分離塔における加熱蒸気量を多量に消費する問
題があった。本発明はこれらの軽質分分離工程における
省エネルギーについて研究した結果、二酸化炭素放散塔
頂部から放散される蒸気のエネルギーの有効利用に着眼
し本発明を完成した。(Problems to be Solved by the Invention) However, such a method for purifying ethylene oxide has a problem of consuming a large amount of heating steam in the light fraction separation column. As a result of research on energy saving in these light fraction separation steps, the present invention has completed the present invention with a focus on effective use of energy of vapor emitted from the top of a carbon dioxide emission column.
（問題点を解決するための手段） 本発明は、エチレンを銀触媒の存在下、分子状酸素含有
ガスと接触気相酸化して生成したエチレンオキシドを含
有する反応生成ガスをエチレンオキシド吸収塔へ導入し
吸収液と向流接触させ、エチレンオキシド吸収塔頂部よ
りのガスの一部はエチレン酸化反応工程へ循環し、残部
を二酸化炭素吸収塔へ導き、アルカリ性吸収液と向流接
触させて二酸化炭素をアルカリ性吸収液に吸収せしめ、
ついでアルカリ性吸収液を二酸化炭素放散塔へ導き、二
酸化炭素放散塔底部を加熱することにより二酸化炭素を
放散分離し、エチレンオキシドを含むエチレンオキシド
吸収塔底液はエチレンオキシド放散塔へ供給し、エチレ
ンオキシド放散塔頂からエチレンオキシドを放散せし
め、エチレンオキシドおよび水を含む留出物を凝縮さ
せ、未凝縮ガスは脱水塔へ供給し、水分を分離し、つい
で軽質分分離塔で軽質分を分離し、ついでエチレンオキ
シド精留塔でエチレンオキシドを精留する工程におい
て、二酸化炭素吸収で吸収され二酸化炭素含有吸収液を
二酸化炭素放散塔の気液接触部上へ供給し、該気液接触
部の上部で発生する放散ガスは分離し、該気液接触部以
下で発生する放散物を軽質分分離塔の加熱源に使用した
後、二酸化炭素を回収することを特徴とする高純度炭素
の回収方法に関するものである。(Means for Solving Problems) The present invention introduces a reaction product gas containing ethylene oxide produced by catalytic vapor phase oxidation of ethylene with a molecular oxygen-containing gas in the presence of a silver catalyst into an ethylene oxide absorption tower. Countercurrent contact with the absorption liquid, part of the gas from the top of the ethylene oxide absorption tower circulates to the ethylene oxidation reaction step, the rest is led to the carbon dioxide absorption tower, and countercurrent contact with the alkaline absorption liquid to absorb the carbon dioxide alkaline Let it absorb into the liquid,
Then, the alkaline absorption liquid is introduced into a carbon dioxide stripping tower, carbon dioxide is stripped and separated by heating the bottom part of the carbon dioxide stripping tower, the ethylene oxide absorption tower bottom liquid containing ethylene oxide is supplied to the ethylene oxide stripping tower, and from the ethylene oxide stripping tower top. Disperse ethylene oxide, condense the distillate containing ethylene oxide and water, supply the uncondensed gas to the dehydration column, separate the water, and then separate the light fraction with the light fraction separation column, and then with the ethylene oxide rectification column. In the step of rectifying ethylene oxide, a carbon dioxide-containing absorption liquid absorbed by carbon dioxide absorption is supplied onto the gas-liquid contact part of the carbon dioxide diffusion column, and the emission gas generated at the upper part of the gas-liquid contact part is separated, The carbon dioxide is recovered after using the emissions generated below the gas-liquid contact section as a heating source for the light fraction separation column. It relates a method of recovering high purity carbon, wherein.
本発明において二酸化炭素は、二酸化炭素吸収塔で吸収
された二酸化炭素含有吸収液が最初に供給される気液接
触より下に設けられた気相部より放散される放散物を軽
質分分離塔の加熱源に使用することによって本発明の目
的が達成される。Carbon dioxide in the present invention, the carbon dioxide-containing absorption liquid absorbed in the carbon dioxide absorption tower is the emission material emitted from the gas phase portion provided below the gas-liquid contact which is first supplied to the light fraction separation tower. Use of the heating source achieves the object of the present invention.
本発明の二酸化炭素含有とアルカリ性吸収液を接触させ
る際に使用するアルカリ性吸収液としては、炭酸ナトリ
ウム、炭酸カリウム、重炭酸ナトリウム、重炭酸カリウ
ム、水酸化ナトリウム、水酸化カリウム、モノエタノー
ルアミン、ジエタノールアミン、トリエタノールアミン
等のアルカノールアミン類、ジグリコールアミン類、グ
リコールエーテル類およびこれらの水溶液が使用され
る。Examples of the alkaline absorbing liquid used when the carbon dioxide-containing and the alkaline absorbing liquid of the present invention are contacted are sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydroxide, potassium hydroxide, monoethanolamine, diethanolamine. , Alkanolamines such as triethanolamine, diglycolamines, glycol ethers and aqueous solutions of these.
本発明の二酸化炭素放散塔において吸収液を二酸化炭素
放散塔に供給する吸収液供給管の下部において気液接触
を実施する手段としては、棚段塔型式および充填塔型式
がある。棚段塔型式の蒸留塔の棚段としては種々あるが
バブルキヤップトレイ、ユニフラックストレイ、ターボ
グリッドトレイ、リップトレイ、フレキシトレイ、シー
プトリ、バラストトレイ等が挙げられる。また、充填塔
型式の放散塔の充填物としては、ラシヒリング、ポール
リング、サドル型リング、スパイラルリング、マクロホ
ンパッキング、インターロックスメタルパッキング（ノ
ートン社）、カスケードミニリング（ドッドウエル
社）、一理論段数あたり10mmHg以下の圧力損失を有する
充填物、織物または編物構造の金網積層板等が挙げられ
る。In the carbon dioxide stripping tower of the present invention, there are a plate column type and a packed column type as means for performing gas-liquid contact in the lower part of the absorbing liquid supply pipe for supplying the absorbing liquid to the carbon dioxide stripping column. There are various trays of the tray column type distillation column, and examples thereof include a bubble cap tray, a uniflux tray, a turbo grid tray, a lip tray, a flexi tray, a sheep tray, and a ballast tray. In addition, as the packing of the packed tower type diffusion tower, Raschig ring, pole ring, saddle type ring, spiral ring, macrophone packing, interlocks metal packing (Norton), cascade mini ring (Dodwell), one theoretical plate Examples thereof include a filler having a pressure loss of 10 mmHg or less, a wire mesh laminated plate having a woven or knit structure, and the like.
特に二酸化炭素放散塔としては、棚段塔型式および充填
塔型式の二酸化炭素放電塔が使用され、複数個の棚およ
び／または充填物を備えた塔が好ましい。In particular, as the carbon dioxide diffusion column, a tray column type and a packed column type carbon dioxide discharge column are used, and a column equipped with a plurality of shelves and / or packings is preferable.
本発明において気液接触部より下に設けられたの気相部
より放散される放散ガスを取得する方法としては、二酸
化炭素放散塔おいて吸収液を二酸化炭素放散塔に供給す
る吸収液供給管の下部に設けられたトレイとトレイの間
の気相部、充填層の気相部、充填層と充填層の間の気相
部が挙げられる。In the present invention, as a method for obtaining the emission gas emitted from the gas phase portion provided below the gas-liquid contact portion, an absorption liquid supply pipe for supplying the absorption liquid to the carbon dioxide emission tower in the carbon dioxide emission tower And the vapor phase portion between the trays provided at the lower part of the column, the vapor phase portion of the packed bed, and the vapor phase portion between the packed bed and the packed layer.
好ましくは少なくとも一理論段数以上に相当するトレイ
または充填層より放散二酸化炭素と取得することができ
る。Preferably, the carbon dioxide released can be obtained from a tray or a packed bed corresponding to at least one theoretical plate or more.
一方、本発明において二酸化炭素放散塔中段から取得し
た二酸化炭素には、水蒸気が同伴しており、高い熱エネ
ルギーを保有している。この熱エネルギーを有するガス
をエチレンオキシド精製工程の軽質分分離塔の加熱器に
導入し、軽質分分離塔の加熱源として使用することによ
り二酸化炭素放散塔蒸気の熱回収を行なうことができる
ものである。On the other hand, in the present invention, the carbon dioxide obtained from the middle stage of the carbon dioxide stripping tower is accompanied by water vapor and possesses high heat energy. By introducing the gas having this heat energy into the heater of the light fraction separation column in the ethylene oxide refining step and using it as the heating source of the light fraction separation column, the heat of the carbon dioxide stripping column vapor can be recovered. .
本発明においてエチレンオキシド吸収塔へ供給される吸
収液の温度は５〜40℃、好ましくは10〜35℃であり、吸
収液の組成はPHが５〜12、好ましくは６〜11、エチレン
グリコール濃度が１〜40重量％、好ましくは５〜30重量
％、消泡剤濃度が0.1ppm以上、好ましくは１〜100pmm、
残り水の範囲に制限される。吸収液中のエチレングリコ
ール濃度を一定に保持するためのエチレンオキシド吸収
塔とエチレンオキシド放散塔とを循環する吸収液の一部
をエチレンオキシド放散塔底部から抜き出し副生エチレ
ングリコールの濃縮塔へ送り、必要により新鮮な水が導
入され制御される。PHの調節は、たとえばカリウム、ナ
トリウムのようなアルカリ金属の水酸化物や炭酸塩等の
吸収液に溶解する化合物を添加することにより行うのが
好ましく、添加剤は具体的には水酸化カリウムまたは水
酸化ナトリウムが好ましい。In the present invention, the temperature of the absorption liquid supplied to the ethylene oxide absorption tower is 5 to 40 ° C., preferably 10 to 35 ° C., and the composition of the absorption liquid is PH 5 to 12, preferably 6 to 11, ethylene glycol concentration is 1 to 40% by weight, preferably 5 to 30% by weight, the concentration of the defoaming agent is 0.1 ppm or more, preferably 1 to 100 pmm,
Limited to the range of remaining water. A part of the absorption liquid that circulates in the ethylene oxide absorption tower and the ethylene oxide diffusion tower to keep the ethylene glycol concentration in the absorption liquid constant is extracted from the bottom of the ethylene oxide diffusion tower and sent to the concentration tower of ethylene glycol as a by-product, and fresh as necessary. Water is introduced and controlled. The pH is preferably adjusted by adding a compound that is soluble in an absorbing solution such as a hydroxide or carbonate of an alkali metal such as potassium or sodium. Specifically, the additive is potassium hydroxide or Sodium hydroxide is preferred.
消泡剤は、エチレンオキシド、副生エチレングリコール
等に不活性であり、吸収液の消泡効果を有するものであ
ればいかなる消泡剤でも使用でき、代表的な例としては
水溶性シリコンエマルジョンが吸収液での分散性、希釈
安定性、熱安定性が優れているので効果的である。The defoaming agent is inert to ethylene oxide, by-product ethylene glycol, etc., and any defoaming agent can be used as long as it has the defoaming effect of the absorbing liquid. As a typical example, water-soluble silicone emulsion is absorbed. It is effective because it has excellent dispersibility in liquid, dilution stability, and thermal stability.
エチレンオキシド吸収塔の操作条件は、反応生成ガス中
のエチレンオキシド濃度が0.5〜５容量％、好ましくは
1.0〜４容量％であり、エチレンオキシド吸収塔の操作
圧は２〜40Kg/cm2Ｇ、好ましくは10〜30Kg/cm2Ｇであ
る。The operating conditions of the ethylene oxide absorption tower are that the concentration of ethylene oxide in the reaction product gas is 0.5 to 5% by volume, preferably
It is 1.0 to 4% by volume, and the operating pressure of the ethylene oxide absorption tower is 2 to 40 Kg / cm 2 G, preferably 10 to 30 Kg / cm 2 G.
エチレンオキシド放散塔の操作上演は、エチレンオキシ
ド放散塔頂圧力0.1〜2kg/cm2G、好ましくは0.3〜0.6kg/
cm2G、エチレンオキシド放散塔頂温度85〜120℃、エチ
レンオキシド放散塔底温度100〜150℃、エチレンオキシ
ド放散塔底エチレンオキシド濃度は30ppm以下、好まし
くは0.5ppm以下である。The operation of the ethylene oxide stripping tower is performed at an ethylene oxide stripping tower top pressure of 0.1 to 2 kg / cm 2 G, preferably 0.3 to 0.6 kg /
cm 2 G, ethylene oxide stripping tower top temperature 85 to 120 ° C., ethylene oxide stripping tower bottom temperature 100 to 150 ° C., ethylene oxide stripping tower bottom ethylene oxide concentration is 30 ppm or less, preferably 0.5 ppm or less.
本発明の特徴は、エチレンを銀触媒の存在下、分子状酸
素含有ガスと接触気相酸化して生成したエチレンオキシ
ドを含有する反応生成ガスをエチレンオキシド吸収塔へ
導入し吸収液と向流触媒させ、エチレンオキシド吸収塔
頂部よりのガスの一部はエチレン酸化反応工程へ循環
し、残部を二酸化炭素吸収塔へ導き、アルカリ性吸収液
と向流接触させて二酸化炭素をアルカリ性吸収液に吸収
せしめ、ついでアルカリ性吸収液を二酸化炭素放散塔へ
導き、二酸化炭素放散塔底部を加熱することにより二酸
化炭素を放散分離し、エチレンオキシドを含むエチレン
オキシド吸収塔底液はエチレンオキシド放散塔へ供給
し、エチレンオキシド放散塔頂からエチレンオキシドを
放散せしめ、エチレンオキシドおよび水を含む留出物を
凝縮させ、未凝縮ガスは脱水塔へ供給し、水分を分離
し、ついで軽質分分離塔で軽質分を分離し、ついでエチ
レンオキシド精留塔でエチレンオキシドを精留する工程
において、二酸化炭素吸収塔で吸収された二酸化炭素含
有吸収液を二酸化炭素放散塔の気液接触部上へ供給し、
該気液接触部の上部で発生する放散ガスは分離し、該気
液接触部以下で発生する放散物を軽質分分離塔の加熱源
に使用した後、二酸化炭素を回収する方法が採用され
る。A feature of the present invention is that, in the presence of a silver catalyst, ethylene is introduced into a reaction product gas containing ethylene oxide produced by catalytic gas-phase oxidation with a molecular oxygen-containing gas and introduced into an ethylene oxide absorption tower to cause a countercurrent catalyst with an absorption liquid, Part of the gas from the top of the ethylene oxide absorption tower is circulated to the ethylene oxidation reaction step, the rest is led to the carbon dioxide absorption tower, and is brought into countercurrent contact with the alkaline absorption liquid to absorb the carbon dioxide into the alkaline absorption liquid, and then the alkaline absorption liquid. The liquid is led to a carbon dioxide stripping tower, carbon dioxide is stripped and separated by heating the bottom of the carbon dioxide stripping tower, the ethylene oxide absorption tower bottom liquid containing ethylene oxide is supplied to the ethylene oxide stripping tower, and ethylene oxide is stripped from the ethylene oxide stripping tower top. To condense the distillate containing ethylene oxide and water to form uncondensed gas. In the process of supplying water to the dehydration tower, separating water, then separating the light fraction in the light fraction separation tower, and then rectifying ethylene oxide in the ethylene oxide rectification tower, the carbon dioxide-containing absorption liquid absorbed in the carbon dioxide absorption tower Is supplied onto the gas-liquid contact part of the carbon dioxide stripping tower,
A method of separating carbon dioxide generated in the upper part of the gas-liquid contacting part, using the emitted gas generated in the gas-liquid contacting part or less as a heating source of a light fraction separation column, and then collecting carbon dioxide is adopted. .
本発明において脱水塔へ供給される供給液の温度は５〜
60℃、好ましくは10〜50℃であり、供給蒸気のエチレン
オキシド濃度は80〜98重量％の範囲である。In the present invention, the temperature of the feed liquid supplied to the dehydration tower is 5 to
The temperature is 60 ° C., preferably 10 to 50 ° C., and the ethylene oxide concentration of the feed steam is in the range of 80 to 98% by weight.
エチレンオキシドの脱水層の操作条件は、脱水塔頂圧力
0.1〜2.0kg/cm2G、好ましくは0.3〜0.6kg/cm2Gの範囲で
ある。The operating conditions for the dehydration layer of ethylene oxide are the top pressure of the dehydration tower.
The range is 0.1 to 2.0 kg / cm 2 G, preferably 0.3 to 0.6 kg / cm 2 G.
脱水塔頂温度は10〜40℃、脱水塔底温度は100〜150℃、
脱水塔底エチレンオキシド濃度は100ppm以下、好ましく
は10ppm以下の範囲である。The dehydration tower top temperature is 10 to 40 ° C, the dehydration tower bottom temperature is 100 to 150 ° C,
The ethylene oxide concentration in the bottom of the dehydration column is 100 ppm or less, preferably 10 ppm or less.
本発明においてエチレンオキシド軽質分分離塔へ供給さ
れる供給液の温度は０〜50℃、好ましくは５〜30℃であ
り、 供給液の組成は大部分がエチレンオキシドで、わずかの
ホルムアルデヒド類および水を含んでいる。In the present invention, the temperature of the feed liquid fed to the ethylene oxide light fractionation column is 0 to 50 ° C., preferably 5 to 30 ° C. The feed liquid composition is mostly ethylene oxide and contains a small amount of formaldehyde and water. I'm out.
軽質分分離塔の操作条件は、軽質分分離塔頂圧力１〜10
kg/cm2G好ましくは３〜7kg/cm2Gの範囲である。The operating conditions of the light separation column are:
kg / cm 2 G It is preferably in the range of 3 to 7 kg / cm 2 G.
軽質分分離塔頂温度30〜90℃、軽質分分離塔底温度30〜
90℃の範囲である。Lights separation tower top temperature 30-90 ℃, Lights separation tower bottom temperature 30-
It is in the range of 90 ° C.
軽質分分離塔底エチレンオキシド濃度は99.5重量％以
上、好ましくは99.5重量％以上の範囲である・ 本発明においてエチレンオキシド精留塔へ供給される供
給液の温度は30〜90℃、好ましくは50〜70℃であり、供
給液の組成はエチレンオキシド濃度が99.5重量％以上、
好ましくは99,95重量％以上の範囲に制御される。The light fraction separation bottom ethylene oxide concentration is in the range of 99.5% by weight or more, preferably 99.5% by weight or more.The temperature of the feed liquid supplied to the ethylene oxide rectification column in the present invention is 30 to 90 ° C, preferably 50 to 70%. ℃, the composition of the feed liquid is ethylene oxide concentration 99.5 wt% or more,
It is preferably controlled in the range of 99,95% by weight or more.
エチレンオキシド精留塔の操作条件は、精留塔頂圧力1.
0〜8.0kg/cm2G好ましくは1.2〜5.0kg/cm2G、精留頂温度
35〜75℃、精留底温度35〜80℃、精留塔底エチレンオキ
シド濃度は30〜90重量％、好ましくは40〜80重量％の範
囲である。The operating conditions of the ethylene oxide rectification column are the top pressure of the rectification column 1.
0 to 8.0 kg / cm 2 G, preferably 1.2 to 5.0 kg / cm 2 G, rectification top temperature
35 to 75 ° C, rectification bottom temperature 35 to 80 ° C, rectification tower bottom ethylene oxide concentration is in the range of 30 to 90% by weight, preferably 40 to 80% by weight.
本発明においてエチレンオキシド精留塔底液はアセトア
ルデヒド、水および酢酸等の高沸点不純物からなる重質
分である。In the present invention, the bottom liquid of the ethylene oxide rectification column is a heavy component composed of high boiling impurities such as acetaldehyde, water and acetic acid.
本発明をさらに詳しく述べるために図−１に基づいて説
明する。The present invention will be described with reference to FIG. 1 in order to describe the present invention in more detail.
図−１においてエチレンを銀触媒の存在下、分子状酸素
含有ガスにより触媒気相酸化して生成するエチレンオキ
シドを含む反応生成ガスを薄管（１）を通して、充填塔
あるいは棚段塔形式のエチレンオキシド吸収塔（２）の
下部へ供給し、導管（３）よりエチレンオキシド吸収塔
（２）の上部へ吸収液を導入し、反応生成ガスと向流接
触させ、反応生成ガス中の99重量％以上のエチレンオキ
シドを回収し、エチレンオキシド吸収塔（２）の塔頂よ
り吸収しなかったエチレン、酸素、二酸化炭素、不活性
ガス（窒素、アルゴン、メタン、エタン）、アルデヒ
ド、酸性物質等のガスは導管（４）を通して、その一部
はライン（５）より反応器（10）へ循環され、残部はラ
イン（６）を経て圧力２〜40Kg/cm2G、温度80〜120℃に
操作された二酸化炭素吸収塔（７）へ導かれ、二酸化炭
素放散塔（12）よりライン（16）を経て供給されるアル
カリ性吸収液と向流接触されて二酸化炭素の他に少量の
エチレン、酸素、二酸化炭素、不活性ガス（窒素、アル
ゴン、メタン、エタン）、アルデヒド、酸化物質等のガ
スが吸収される。二酸化炭素吸収塔（７）の塔頂より二
酸化炭素を吸収されたガスはライン（８）を経てライン
（９）へ送られ、新たに補充されるエチレン、希釈ガス
等と混合された後、反応器（10）へ循環される。二酸化
炭素吸収塔（７）で二酸化炭素ガスを吸収した二酸化炭
素ガス濃厚吸収液はライン（11）を経て圧力0.1〜5Kg/c
m2G、温度80〜120℃で操作され、塔底部にリボイラー
（17）を設置した二酸化炭素放散塔（12）の塔頂部に供
給される。二酸化炭素放散塔（12）の塔頂部の供給部に
おいて吸収液は二酸化炭素吸収塔（７）と二酸化炭素放
散塔（12）の圧力の差によって圧力フラッシュを起し、
吸収液中の10〜80容量％の二酸化炭素ガスと大部分のエ
チレン、酸素、二酸化炭素、不活性ガス（窒素、アルゴ
ン、メタン、エタン）はライン（13）を通して吸収液か
ら分離される。圧力フラッシュにより二酸化炭素ガスの
一部を分離された残りの二酸化炭素ガス吸収液は供給液
部の下方に設けた気液接触部（14）に入り、リボイラー
（17）より発生した蒸気および気液接触剤（14）以下の
部分から発生した二酸化炭素を主とするガスと向流接触
して吸収液中の二酸化炭素およびその他のイナートガス
の大部分が吸収液から分離される。吸収液供給部の下方
に設けた気液接触部（14）の最上部から下方、好ましく
は気液接触に必要な一理論段数以上に相当する気液接触
部（14）の下部の二酸化炭素放散塔（12）内部から高純
度二酸化炭素を取り出しライン（15）から放散されたガ
スは、軽質分分離塔（51）のリボイラー（70）に導入
し、加熱源として使用された後、導管（74）により高純
度二酸化炭素が得られる。In Figure 1, the reaction product gas containing ethylene oxide produced by catalytic gas phase oxidation of ethylene with a molecular oxygen-containing gas in the presence of a silver catalyst is passed through a thin tube (1) to absorb ethylene oxide in a packed or plate column format. It is supplied to the lower part of the tower (2), the absorption liquid is introduced from the conduit (3) to the upper part of the ethylene oxide absorption tower (2), and is brought into countercurrent contact with the reaction product gas, and 99% by weight or more of ethylene oxide in the reaction product gas. The gas such as ethylene, oxygen, carbon dioxide, inert gas (nitrogen, argon, methane, ethane), aldehyde, acidic substance, etc. which was not absorbed from the top of the ethylene oxide absorption tower (2) was recovered by the conduit (4). through, a part thereof is circulated from the line (5) to the reactor (10), the carbon dioxide absorption engineered remainder via line (6) pressure 2~40Kg / cm 2 G, the temperature 80 to 120 ° C. Introduced to the tower (7) and in countercurrent contact with the alkaline absorbing liquid supplied from the carbon dioxide desorption tower (12) through the line (16), and in addition to carbon dioxide, a small amount of ethylene, oxygen, carbon dioxide, inert gas. Gases such as gases (nitrogen, argon, methane, ethane), aldehydes, and oxidants are absorbed. The gas in which carbon dioxide is absorbed from the top of the carbon dioxide absorption tower (7) is sent to the line (9) via the line (8), and is mixed with newly supplemented ethylene, diluent gas, etc., and then reacted. It is circulated to the vessel (10). The carbon dioxide absorption liquid that has absorbed carbon dioxide in the carbon dioxide absorption tower (7) passes through the line (11) and has a pressure of 0.1 to 5 kg / c.
It is operated at m 2 G and a temperature of 80 to 120 ° C., and is supplied to the top of a carbon dioxide stripping column (12) having a reboiler (17) installed at the bottom of the column. In the supply section at the top of the carbon dioxide stripping tower (12), the absorbing liquid causes a pressure flush due to the difference in pressure between the carbon dioxide stripping tower (7) and the carbon dioxide stripping tower (12),
10-80% by volume of carbon dioxide gas and most of ethylene, oxygen, carbon dioxide and inert gases (nitrogen, argon, methane, ethane) in the absorbing liquid are separated from the absorbing liquid through the line (13). The remaining carbon dioxide gas absorption liquid from which part of the carbon dioxide gas has been separated by the pressure flush enters the gas-liquid contact part (14) provided below the supply liquid part, and the vapor and gas-liquid generated from the reboiler (17). Most of carbon dioxide and other inert gases in the absorbing liquid are separated from the absorbing liquid by countercurrently contacting carbon dioxide generated mainly from the contacting agent (14) and the parts below. Carbon dioxide emission below the uppermost part of the gas-liquid contact part (14) provided below the absorbing liquid supply part, preferably at the lower part of the gas-liquid contact part (14) corresponding to one or more theoretical plates required for gas-liquid contact. The high-purity carbon dioxide is taken out from the inside of the tower (12), and the gas released from the line (15) is introduced into the reboiler (70) of the light fraction separation tower (51) and used as a heating source, and then the conduit (74). High-purity carbon dioxide is obtained by).
気液接触部（14）での二酸化炭素ガス吸収液中に含まれ
る不活性ガス（窒素、アルゴン、メタン、エタン）は気
液接触部（14）の下部から上昇してくる極く微量の不活
性ガス（窒素、アルゴン、メタン、エタン）を含む二酸
化炭素ガスと水蒸気とによって気液接触部（14）内で向
流気液接触を起してた放散され、不活性ガス（窒素、ア
ルゴン、メタン、エタン）の濃度は極めて低くなる。し
たがって放散後の二酸化炭素ガスを取り出せば高純度二
酸化炭素が得られる。The inert gas (nitrogen, argon, methane, ethane) contained in the carbon dioxide gas absorption liquid in the gas-liquid contact part (14) rises from the lower part of the gas-liquid contact part (14) and is a very small amount of impurities. Carbon dioxide gas containing active gas (nitrogen, argon, methane, ethane) and steam caused countercurrent gas-liquid contact in the gas-liquid contact section (14) to be diffused, and inert gas (nitrogen, argon, The concentrations of methane and ethane) are extremely low. Therefore, high-purity carbon dioxide can be obtained by removing the carbon dioxide gas after the emission.
二酸化炭素塔（12）が充填塔の場合は充填層内および充
填層と充填層との間から、また棚段塔の場合はトレイと
トレイの間から吸収液を混入しないようにしてガスを抜
き出せば高純度二酸化炭素ガスのが得られる。When the carbon dioxide tower (12) is a packed tower, the gas should be extracted from within the packed bed and between packed beds and between trays when it is a tray tower so that the absorbent is not mixed. For example, high-purity carbon dioxide gas can be obtained.
本発明の高純度二酸化炭素ガスは二酸化炭素吸収塔で吸
収された二酸化炭素の20〜90容量％である。The high-purity carbon dioxide gas of the present invention is 20 to 90% by volume of carbon dioxide absorbed in the carbon dioxide absorption tower.
またエチレンオキシド吸収塔（２）の塔底液を導管（1
9）を通して熱交換器（20）へ送りエチレンオキシド放
散塔底液と熱交換して温度70〜110℃に高め、導管（2
1）により気液分離タンク（22）へ送られ一部エチレン
オキシドおよび水を含む軽質分ガスが導管（23）により
分離される。軽質分ガスをフラッシュした残部の吸収液
を導管（24）を通して塔頂圧力0.1〜2Kg/cm2G、温度85
〜120℃のエチレンオキシド放散塔（25）の上部へ供給
し、エチレンオキシド放散部（25）の加熱器（30）より
水蒸気またはダウサム（ダウ社商品）等の加熱媒体で導
管（31）を通して加熱するか、または接触エチレンオキ
シド放散塔（25）の底部へ水蒸気を導入する加熱方式に
より加熱し、吸収液中に含まれるエチレンオキシドの99
重量％以上を放散せしめ、エチレンオキシド放散塔（2
5）の底部よりエチレンオキシドを実質的に含まない温
度100〜150℃の放散塔底液の一部は導管（32）および導
管（34）を通して熱交換器（20）でエチレンオキシド吸
収塔（２）の塔底液と熱交換し、導管（35）を通して、
さらに導管（37）に冷却水が通る冷却器（36）により冷
却し、ついで吸収液中のエチレングリコール濃度を調節
するため新鮮な水を導管（39）を通して導入し、必要に
より、吸収液中のpHを調節するため水酸化カリウム水溶
液を添加し、吸収液中の消泡剤濃度を調節するため消泡
剤をエチレンオキシド吸収塔（２）へそれぞれ導入する
ことができる。In addition, the bottom liquid of the ethylene oxide absorption tower (2) is introduced into the conduit (1
9) to the heat exchanger (20) and heat exchange with the bottom liquid of ethylene oxide stripping tower to raise the temperature to 70-110 ℃,
The light component gas partially sent to the gas-liquid separation tank (22) by (1) and partially containing ethylene oxide and water is separated by the conduit (23). The remaining absorption liquid after flushing the light gas is passed through the conduit (24) and the top pressure is 0.1 to 2 kg / cm 2 G and the temperature is 85.
Is it supplied to the upper part of the ethylene oxide diffusion tower (25) at ~ 120 ° C and heated through the conduit (31) with steam or a heating medium such as Dowsome (commercial product from Dow) from the heater (30) of the ethylene oxide diffusion section (25)? Of the ethylene oxide contained in the absorption liquid by heating with a heating system in which steam is introduced into the bottom of the catalytic ethylene oxide stripping tower (25).
The ethylene oxide diffusion tower (2
From the bottom of 5), a part of the bottom liquid of the stripping tower at a temperature of 100 to 150 ° C which does not substantially contain ethylene oxide is passed through the conduit (32) and the conduit (34) through the heat exchanger (20) to the ethylene oxide absorption tower (2). Heat exchange with the bottom liquid, through the conduit (35),
Further, cooling is performed by a cooler (36) through which cooling water passes through the conduit (37), and then fresh water is introduced through the conduit (39) to adjust the ethylene glycol concentration in the absorbent, and if necessary, the An aqueous potassium hydroxide solution may be added to adjust the pH, and an antifoaming agent may be introduced into the ethylene oxide absorption tower (2) to adjust the concentration of the antifoaming agent in the absorbing solution.
エチレンを分子状酸素で酸化する酸化工程およびエチレ
ンオキシド放散工程の間で吸収液中にエチレンオキシド
と水との加水反応で生成する副生エチレングリコールお
よびホルムアルデヒド等の低沸点不純物、アセトアルデ
ヒドおよび酢酸等の高沸点不純物の増加を防ぐためエチ
レンオキシド放散塔（25）の塔底より導管（32）および
（33）を通してエチレンオキシド放散塔（25）の底液を
抜き出し、副生エチレングリコール濃度工程に送られ
る。Low boiling point impurities such as by-produced ethylene glycol and formaldehyde, and high boiling points such as acetaldehyde and acetic acid, which are produced by the hydrolysis reaction of ethylene oxide and water in the absorption liquid between the oxidation step of oxidizing ethylene with molecular oxygen and the ethylene oxide emission step In order to prevent the increase of impurities, the bottom liquid of the ethylene oxide stripping tower (25) is extracted from the bottom of the ethylene oxide stripping tower (25) through conduits (32) and (33) and sent to a by-product ethylene glycol concentration step.
一方、エチレンオキシド放散塔（25）の塔頂部より放散
されるエチレンオキシドを含む放散蒸気は導管（26）を
通して、導管（28）に冷却水が通る凝縮器（27）へ送
り、凝縮液は導管（29）を通してエチレンオキシド放散
塔（25）の塔頂部へ還流し、未凝縮蒸気は導管（40）を
通して脱水塔（41）へ供給される。On the other hand, the vaporized vapor containing ethylene oxide that is diffused from the top of the ethylene oxide stripping tower (25) is sent through the conduit (26) to the condenser (27) through which the cooling water passes through the conduit (28), and the condensate is discharged through the conduit (29). ) To the top of the ethylene oxide stripping tower (25), and the uncondensed vapor is supplied to the dehydration tower (41) through the conduit (40).
脱水塔（41）の加熱器（48）により水蒸気またはダウサ
ム（ダウ社商品）等の加熱媒体で導管（68）を通して加
熱するか、または直接脱水塔（41）の下部へ水蒸気を導
入する加熱方式により加熱し、脱水塔（41）の塔底より
導管（50）を通してエチレンオキシドを実質的に含まな
い水が抜き出される。A heating method in which the heater (48) of the dehydration tower (41) heats with steam or a heating medium such as Dowsome (commercial product of Dow Company) through the conduit (68) or directly introduces the steam into the lower part of the dehydration tower (41). Water is extracted from the bottom of the dehydration tower (41) through the conduit (50) and substantially free of ethylene oxide.
脱水塔（41）の塔頂部よりエチレンオキシドを含む蒸気
は導管（42）を通して、導管（44）に冷却水またはブラ
インが通る凝縮器（43）へ送り、凝縮液の一部は導管
（46）を通して脱水塔（41）の塔頂部へ還流し、凝縮器
（43）の未凝縮蒸気は導管（45）を通して再エチレンオ
キシド吸収塔（図示していない）へ供給される。Vapor containing ethylene oxide is sent from the top of the dehydration tower (41) to the condenser (43) through which the cooling water or brine passes through the conduit (42), and part of the condensate passes through the conduit (46). Refluxing to the top of the dehydration tower (41), the uncondensed vapor in the condenser (43) is supplied to the ethylene oxide absorption tower (not shown) through the conduit (45).
凝縮器（43）の凝縮液の他部は導管（47）を通して軽質
分分離塔（51）へ供給される。軽質分分離塔（51）の塔
頂部より軽質分ガスを含むエチレンオキシド蒸気は導管
（52）を通して凝縮器（53）へ送り、凝縮液は導管（5
6）を通して軽質分分離塔（51）の塔頂部へ還流し、未
凝縮蒸気は導管（55）を通してエチレンオキシドを回収
するため再エチレンオキシド吸収塔（図樹木しない）へ
供給される。The other part of the condensate of the condenser (43) is supplied to the light fraction separation column (51) through the conduit (47). Ethylene oxide vapor containing light gas is sent from the top of the light separation column (51) to the condenser (53) through the conduit (52), and the condensate is discharged through the conduit (5).
It is refluxed to the top of the light fraction separation column (51) through 6), and the uncondensed vapor is supplied to the re-ethylene oxide absorption column (no tree) for recovering ethylene oxide through the conduit (55).
軽質分分離塔（51）の加熱器（70）には二酸化炭素放散
塔（12）の棚段または充填層（14）の下部から導管（1
5）により二酸化炭素と水蒸気の混合蒸気が導入され加
熱源とした後、導管（71）により若干の水蒸気を含んだ
高純度二酸化炭素が得られる。The heater (70) of the light fractionation column (51) is connected to the tray (1) from the bottom of the tray or the packed bed (14) of the carbon dioxide stripping column (12).
After the mixed steam of carbon dioxide and steam is introduced by 5) and used as a heating source, high purity carbon dioxide containing a small amount of steam can be obtained by the conduit (71).
軽質分分離塔（51）の塔底液は導管（59）を通してエチ
レンオキシド精留塔（60）へ供給される。The bottom liquid of the light fraction separation column (51) is supplied to the ethylene oxide rectification column (60) through the conduit (59).
エチレンオキシド精留塔（60）の加熱器（67）により水
蒸気またはダウサム（ダウ社商品）等の加熱媒体で導管
（68）を通して加熱する方式により加熱し、エチレンオ
キシド精留塔（60）の塔底温度35〜85℃、エチレンオキ
シド精留塔底圧力1.1〜8.2Kg/cm2Gで精留を行ない、エ
チレンオキシド精留塔頂より塔頂温度29〜81℃、塔頂部
圧力１〜8kg/cm2Gのエチレンオキシド蒸気を導管（61）
を通して、エチレンオキシド凝縮器（62）へ送り、エチ
レンオキシドを液化し、一部は導管（65）を通してエチ
レンオキシド精留塔（60）の塔頂部へ還流液として供給
し、他部は導管（66）を通してエチレンオキシド製品と
して抜き出した。The heater (67) of the ethylene oxide rectification column (60) is heated by steam or a heating medium such as Dowsome (commercially available from Dow) through a conduit (68) to heat the bottom of the ethylene oxide rectification column (60). The rectification is performed at 35 to 85 ° C and the ethylene oxide rectification column bottom pressure of 1.1 to 8.2 Kg / cm 2 G. The ethylene oxide rectification column top temperature is 29 to 81 ° C and the column top pressure is 1 to 8 kg / cm 2 G. Pipes with ethylene oxide vapor (61)
Through an ethylene oxide condenser (62) to liquefy the ethylene oxide, a part of which is fed as a reflux liquid to the top of the ethylene oxide rectification column (60) through a conduit (65), and the other part of which is fed through a conduit (66). Extracted as a product.
エチレンオキシド精留塔（60）の塔底液はアセトアルデ
ヒド、水、および酢酸等の高沸点不純物の重質分分離の
ため必要により導管（69）を通して抜き出される。The bottom liquid of the ethylene oxide rectification column (60) is withdrawn through a conduit (69) as necessary for separating heavy components such as acetaldehyde, water, and high boiling point impurities such as acetic acid.
ここで二酸化炭素放散塔（12）より導管（15）を通して
軽質分分離塔（51）の加熱器（70）へ導入された二酸化
炭素と水蒸気の混合蒸気は所定の熱量を軽質分分離塔
（51）に与えた後、導管（73）に冷却水が通る冷却器
（72）へ送られ、一部の水蒸気を凝縮分離した後、導管
（74）により僅かの水分を含む高純度二酸化炭素が得ら
れる。つづいて導管（74）から脱水工程に送られ高純度
二酸化炭素が得られる。Here, the mixed vapor of carbon dioxide and steam introduced from the carbon dioxide stripping tower (12) through the conduit (15) into the heater (70) of the light fraction separating tower (51) gives a predetermined heat quantity to the light fraction separating tower (51). ) Is fed to a cooler (72) through which cooling water passes through a conduit (73) to condense and separate a part of water vapor, and then a conduit (74) yields high-purity carbon dioxide containing a small amount of water. To be Subsequently, it is sent to the dehydration process through the conduit (74) to obtain high-purity carbon dioxide.
本発明をさらに詳しく述べるために従来公知のエチレン
オキシド製造プロセスにおける二酸化炭素製造方法を図
−２に基づいて説明する。In order to describe the present invention in more detail, a carbon dioxide production method in a conventionally known ethylene oxide production process will be described with reference to FIG.
図−２においてエチレンを銀触媒の存在下、分子状酸素
含有ガスにより接触気相酸化して生成するエチレンオキ
シドを含む反応生成ガスを導管（１）を通して、充填塔
あるいは棚段塔形式のエチレンオキシド吸収塔（２）の
下部へ供給し、導管（３）よりエチレンオキシド供給塔
（２）の上部へ吸収液を導入し、反応生成ガスと向流接
触させ、反応生成ガス中の99重量％以上のエチレンオキ
シドを回収し、エチレンオキシド吸収塔（２）の塔頂よ
り吸収しなかったエチレン、酸素、二酸化炭素、不活性
ガス（窒素、アルゴン、メタン、エタン）、アルデヒ
ド、酸性物質等のガスは導管（４）を通して二酸化炭素
吸収工程および／または酸化反応工程へ循環される。こ
の吸収工程においてエチレンオキシドの他、エチレン、
酸素、二酸化炭素、不活性ガス（窒素、アルゴン、メタ
ン、エタン、）ならびにエチレン酸化反応工程で生成し
たホルムアルデヒド等の低沸点不純物、アセトアルデヒ
ド、酢酸等の高沸点不純物もその実質量が同時に吸収さ
れる。エチレンオキシド吸収塔（２）の塔底液を導管
（19）を通して熱交換器（20）へ送り、エチレンオキシ
ド放散塔底液と熱交換して温度70〜110℃に高め、導管
（21）により気液分離タンク（22）へ送られ一部エチレ
ンオキシド、水を含む不活性ガスの軽質分ガスが導管
（23）により分離される。軽質分ガスをスラッシュした
残部の吸収液を導管（24）を通して塔頂圧力0.1〜2Kg/c
m2G、温度85〜120℃のエチレンオキシド放散塔（25）の
上部へ供給し、エチレンオキシド放散塔（25）の加熱器
（30）より水蒸気またはダウサム（ダウ社、熱媒体商
品）等の加熱媒体で導管（31）を通して加熱するか、ま
たは直接エチレンオキシド放散塔（25）の底部へ水蒸気
を導入する加熱方式により加熱し、吸収液中に含まれる
エチレンオキシドの99重量％以上を放散せしめ、エチレ
ンオキシド放散塔（25）の底部よりエチレンオキシドを
実質的に含まない温度100〜150℃のエチレンオキシド放
散塔底液の一部は導管（32）および導管（34）を通して
熱交換器（20）でエチレンオキシド吸収塔（２）の塔底
液と熱交換し、導管（35）を通して、さらに導管（37）
に冷却水が通る冷却器（36）により冷却し、ついで吸収
液中のエチレングリコール濃度を調節するため新鮮な水
を導管（39）を通して導入し、必要により、吸収液中の
pHを調節するため水酸化カリウム水溶液を添加し、吸収
液中の消泡剤濃度を調節するため消泡剤をエチレンオキ
シド吸収塔（２）へそれぞれ導入することができる。エ
チレンを分子状酸素で酸化する酸化工程およびエチレン
オキシド放散工程の間で吸収液中にエチレンオキシドと
水との加水反応で生成する副性エチレングリコールおよ
びホルムアルデヒド等の低沸点不純物、アセトアルデヒ
ドおよび酢酸等の高沸点不純物の増加を防ぐためエチレ
ンオキシド放散塔（25）の塔底部より導管（32）および
（33）を通してエチレンオキシド放散塔（25）の塔底液
を抜き出し、副生エチレングリコール濃縮工程に送られ
る。In Fig. 2, a reaction product gas containing ethylene oxide produced by catalytic gas-phase oxidation of ethylene with a molecular oxygen-containing gas in the presence of a silver catalyst is passed through a conduit (1) through a packed column or a tray column type ethylene oxide absorption column. It is supplied to the lower part of (2), the absorption liquid is introduced from the conduit (3) to the upper part of the ethylene oxide supply tower (2), and is brought into countercurrent contact with the reaction product gas, and 99% by weight or more of ethylene oxide in the reaction product gas is introduced. Gases such as ethylene, oxygen, carbon dioxide, inert gases (nitrogen, argon, methane, ethane), aldehydes and acidic substances which were recovered and not absorbed from the top of the ethylene oxide absorption tower (2) were passed through the conduit (4). It is recycled to the carbon dioxide absorption step and / or the oxidation reaction step. In this absorption step, in addition to ethylene oxide, ethylene,
A substantial amount of oxygen, carbon dioxide, an inert gas (nitrogen, argon, methane, ethane) as well as low boiling impurities such as formaldehyde produced in the ethylene oxidation reaction step and high boiling impurities such as acetaldehyde and acetic acid are simultaneously absorbed. The bottom liquid of the ethylene oxide absorption tower (2) is sent to the heat exchanger (20) through the conduit (19) and heat-exchanged with the bottom liquid of the ethylene oxide diffusion tower to raise the temperature to 70 to 110 ° C. The inert gas light component gas containing a part of ethylene oxide and water is sent to the separation tank (22) and separated by the conduit (23). The residual absorption liquid after slushing the light component gas is passed through the conduit (24) and the column top pressure is 0.1 to 2 Kg / c.
Supply to the upper part of the ethylene oxide diffusion tower (25) with m 2 G and temperature of 85 to 120 ℃, and from the heater (30) of the ethylene oxide diffusion tower (25) steam or Dowsum (Dow Company, heat medium product) etc. heating medium The ethylene oxide diffusion tower is heated through the conduit (31) or by a heating method in which steam is directly introduced into the bottom of the ethylene oxide diffusion tower (25) to diffuse 99% by weight or more of the ethylene oxide contained in the absorption liquid. From the bottom of (25), a part of the bottom liquid of the ethylene oxide desorption column at a temperature of 100 to 150 ° C. which does not substantially contain ethylene oxide is passed through the conduit (32) and the conduit (34) through the heat exchanger (20) to the ethylene oxide absorption tower (2). ) Heat exchange with the bottom liquid of the above), through the conduit (35), and further through the conduit (37)
It is cooled by a cooler (36) through which cooling water passes, and then fresh water is introduced through a conduit (39) to adjust the ethylene glycol concentration in the absorption liquid, and if necessary,
An aqueous potassium hydroxide solution may be added to adjust the pH, and an antifoaming agent may be introduced into the ethylene oxide absorption tower (2) to adjust the concentration of the antifoaming agent in the absorbing solution. Low boiling point impurities such as ethylene glycol and formaldehyde, which are secondary by-products produced by the hydrolysis reaction of ethylene oxide and water in the absorption liquid between the oxidation step of oxidizing ethylene with molecular oxygen and the ethylene oxide emission step, and high boiling points of acetaldehyde and acetic acid In order to prevent the increase of impurities, the bottom liquid of the ethylene oxide stripping tower (25) is extracted from the bottom of the ethylene oxide stripping tower (25) through the conduits (32) and (33) and sent to the by-product ethylene glycol concentration step.
一方、エチレンオキシド放散塔（25）の塔頂部より放散
されるエチレンオキシドを含む放散蒸気に導管（26）を
通して、導管（28）に冷却水が通る凝縮器（27）へ送
り、凝縮液は導管（29）を通してエチレンオキシド放散
塔（25）の塔頂部へ還流し、未凝縮蒸気は導管（40）を
通して脱水塔（41）へ供給される。On the other hand, the vaporized steam containing ethylene oxide that is diffused from the top of the ethylene oxide stripping tower (25) is sent through a conduit (26) to a condenser (27) through which cooling water passes through the conduit (28), and the condensate is discharged from the conduit (29). ) To the top of the ethylene oxide stripping tower (25), and the uncondensed vapor is supplied to the dehydration tower (41) through the conduit (40).
脱水塔（41）の加熱器（48）により水蒸気またはダウサ
ム（ダウ社商品）等の加熱媒体で導管（49）を通して加
熱するか、または直接脱水塔（41）の下部へ水蒸気を導
入する加熱方式により加熱し、脱水塔（41）の塔底より
導管（50）を通してエチレンオキシドを含まない水が抜
き出される。A heating method in which the heater (48) of the dehydration tower (41) heats with steam or a heating medium such as Dowsome (commercial product of Dow Company) through the conduit (49) or directly introduces the steam into the lower part of the dehydration tower (41). And water containing no ethylene oxide is extracted from the bottom of the dehydration tower (41) through the conduit (50).
脱水塔（41）の塔頂部よりエチレンオキシドを含む蒸気
は導管（42）を通して、導管（44）に冷却水またはブラ
インが通る凝縮器（43）へ送り、凝縮液は導管（46）を
通して脱水塔（41）の塔頂部へ還流し、凝縮器（43）の
未凝縮蒸気は導管（45）を通して再エチレンオキシド吸
収塔（図示していない）へ供給される。The vapor containing ethylene oxide from the top of the dehydration tower (41) is sent through the conduit (42) to the condenser (43) through which cooling water or brine passes through the conduit (44), and the condensate is passed through the conduit (46). After refluxing to the top of 41), the uncondensed vapor in the condenser (43) is fed to the ethylene oxide absorption tower (not shown) through the conduit (45).
凝縮器（43）の凝縮液の他部は導管（47）を通して軽質
分分離塔（51）へ供給される。The other part of the condensate of the condenser (43) is supplied to the light fraction separation column (51) through the conduit (47).
軽質分分離塔（51）の加熱器（57）へ水蒸気またはダウ
サム（ダウ社商品）部の加熱媒体で導管（58）を通して
加熱する方式により加熱し、軽質分分離塔（51）の塔頂
部より軽質分を含むエチレンオキシド蒸気は導管（52）
を通して凝縮器（53）へ送り、凝縮液は導管（56）を通
して軽質分分離塔（51）の塔頂部へ還流し、未凝縮蒸気
は導管（55）を通してエチレンオキシドを回収するため
再エチレンオキシド吸収塔（図示してない）ヘ供給され
る。軽質分分離塔（51）の塔底より導管（59）を通して
エチレンオキシド精留塔（60）へ供給される。Heating is performed by heating the heater (57) of the light fraction separation column (51) with steam or a heating medium of Dow Sam (commercial product of Dow) through the conduit (58), and then heating from the top of the light fraction separation column (51). Pipes for ethylene oxide vapor containing light components (52)
To the condenser (53) through the conduit (56) to reflux to the top of the light fraction separation column (51), and the uncondensed vapor through the conduit (55) to recover ethylene oxide and the ethylene oxide absorption tower ( (Not shown). It is supplied to the ethylene oxide rectification column (60) from the bottom of the light fraction separation column (51) through the conduit (59).
エチレンオキシド精留塔（60）の加熱器（67）により水
蒸気またはダウサム（ダウ社商品）等の加熱媒体で導管
（68）を通して加熱する方式により加熱し、エチレンオ
キシド精留塔（60）の加熱器（67）へ導管（68）より圧
力2.2kg/cm2Gの水蒸気を供給し、エチレンオキシド精留
塔（60）の塔底温度62℃、エチレンオキシド精留塔底圧
3.7kg/cm2Gで精留を行ない、エチレンオキシド精留塔頂
より塔頂温度54℃、塔頂圧3.5kg/cm2Gのエチレンオキシ
ド蒸気を導管（61）を通して、凝縮器（62）へ送りエチ
レンオキシド蒸気は液化し、液化した一部は導管（65）
を通してエチレンオキシド精留塔（60）の塔頂部へ還流
液として導入し、液化した他部は導管（66）を通してエ
チレンオキシド製品として抜き出される。The ethylene oxide rectification tower (60) is heated by a heater (67) through a conduit (68) with steam or a heating medium such as Dowsome (commercially available from Dow) to heat the ethylene oxide rectification tower (60). 67) is supplied with steam of pressure 2.2 kg / cm 2 G from the conduit (68), the bottom temperature of the ethylene oxide rectification column (60) is 62 ° C, the ethylene oxide rectification column bottom pressure
Fractionation is carried out at 3.7 kg / cm 2 G, and ethylene oxide vapor with a column top temperature of 54 ° C and a column top pressure of 3.5 kg / cm 2 G is sent from the top of the ethylene oxide rectification column to the condenser (62) through the conduit (61). Ethylene oxide vapor liquefies, part of the liquefied conduit (65)
Is introduced into the top of the ethylene oxide rectification column (60) as a reflux liquid, and the other liquefied part is withdrawn as an ethylene oxide product through a conduit (66).
エチレンオキシド精留塔（60）の凝縮器（62）の未凝縮
蒸気は導管（64）を通してエチレンオキシドを回収する
ため再エチレンオキシド吸収塔（図示しない）へ供給さ
れる。The uncondensed vapor in the condenser (62) of the ethylene oxide rectification column (60) is supplied to a re-ethylene oxide absorption column (not shown) for recovering ethylene oxide through the conduit (64).
エチレンオキシド精留塔（60）の塔底液はアセトアルデ
ヒド、水、および酢酸等の高沸点不純物の重質分分離の
ため必要により導管（69）を通して抜き出される。The bottom liquid of the ethylene oxide rectification column (60) is withdrawn through a conduit (69) as necessary for separating heavy components such as acetaldehyde, water, and high boiling point impurities such as acetic acid.
このプロセスにおいて、二酸化炭素放散塔（12）の塔頂
部より水蒸気を含む二酸化炭素が導管（13）により、導
管（77）に水が通る凝縮器（76）へ送られ、二酸化炭素
に同伴している水蒸気が凝縮分離された後、導管（79）
により、不純物を含有する二酸化炭素は、二酸化炭素精
製工程に送られ不純物を除去した後、純度の高い二酸化
炭素として得られる。In this process, carbon dioxide containing water vapor is sent from the top of the carbon dioxide stripping tower (12) by a conduit (13) to a condenser (76) through which water passes through the conduit (77) and is entrained in the carbon dioxide. After water vapor is condensed and separated, conduit (79)
Thus, the carbon dioxide containing impurities is sent to the carbon dioxide refining step to remove the impurities, and then obtained as high-purity carbon dioxide.
（実施例） 以下、実施例により本発明をさらに詳細に説明する。し
かし本発明はこの実施例のみによって本発明の範囲を規
制するものでない。(Examples) Hereinafter, the present invention will be described in more detail with reference to Examples. However, the present invention does not limit the scope of the present invention by this embodiment alone.
実施例１ 図−１において、エチレンを銀触媒の存在下、分子状酸
素含有ガスにより接触気相酸化して生成するエチレンオ
キシドを含む反応生成ガスを導管（１）を通して、充填
塔あるいは棚段塔形式のエチレンオキシド吸収塔（２）
の下部へ供給し、導管（３）よりエチレンオキシド吸収
塔（２）の上部へ吸収液を導入し、反応生成ガスと向流
接触させ、反応生成ガス中の99重量％以上のエチレンオ
キシドを回収し、エチレンオキシド吸収塔（２）の塔頂
より吸収しなかったエチレン、酸素、二酸化炭素、不活
性ガス（窒素、アルゴン、メタン、エタン）、アルデヒ
ド、酸性物質等のガスは導管（４）を通して二酸化炭素
吸収工程および／または酸化反応工程へ循環した。この
吸収工程においてエチレンオキシドの他、エチレン、酸
素、二酸化炭素、不活性ガス（窒素、アルゴン、メタ
ン、エタン、）ならびにエチレン酸化反応工程で生成し
たホルムアルデヒド等の低沸点不純物、アセトアルデヒ
ド、酢酸等の高沸点不純物もその実質量が同時に吸収さ
れた、エチレンオキシド吸収塔（２）の塔底液を導管
（19）を通して熱交換器（20）へ送り、エチレンオキシ
ド放散塔底液と熱交換して温度105℃に高め、導管（2
1）により気液分離タンク（22）へ送り、一部エチレン
オキシドおよび水を含む軽質分分離ガスが導管（23）に
より分離された。軽質分ガスをフラッシュした残部の吸
収液は導管（24）を通して塔頂圧力0.4Kg/cm2G、温度9
9.6℃のエチレンオキシド放散塔（25）の上部へ供給
し、エチレンオキシド放散器（25）の加熱器（30）より
水蒸気を通して加熱し、吸収液中に含まれるエチレンオ
キシドの99重量％以上を放散せしめ、エチレンオキシド
放散塔（25）の底部よりエチレンオキシドを実質的に含
まない温度114℃のエチレンオキシド放散塔底液の一部
は導管（32）および導管（34）を通して熱交換器（20）
でエチレンオキシド吸収塔（２）の塔底液と熱交換し、
導管（35）を通して、さらに導管（37）に冷却水が通る
冷却器（36）により冷却し、ついで吸収液中のエチレン
グリコール濃度を調節するため新鮮な水を導管（39）を
通して導入した。エチレンを分子状酸素で酸化する酸化
工程およびエチレンオキシド放散工程の間で吸収液中に
エチレンオキシドと水との加水反応で生成する副生エチ
レングリコールおよびホルムアルデヒド等の低沸点不純
物、アセトアルデヒドおよび酢酸等の高沸点不純物の増
加を防ぐためエチレンオキシド放散塔（25）の塔底より
導管（32）および（33）を通してエチレンオキシド放散
塔（25）の底液を抜き出し、副生エチレングリコール濃
縮工程に送った。Example 1 In FIG. 1, a reaction product gas containing ethylene oxide produced by catalytic gas-phase oxidation of ethylene with a molecular oxygen-containing gas in the presence of a silver catalyst is passed through a conduit (1) to form a packed column or a plate column. Ethylene oxide absorption tower (2)
Of the ethylene oxide absorption tower (2) through the conduit (3), and brought into countercurrent contact with the reaction product gas to recover 99% by weight or more of ethylene oxide in the reaction product gas. Gases such as ethylene, oxygen, carbon dioxide, inert gases (nitrogen, argon, methane, ethane), aldehydes and acidic substances that have not been absorbed from the top of the ethylene oxide absorption tower (2) are absorbed by carbon dioxide through the conduit (4). It was recycled to the process and / or the oxidation reaction process. In this absorption process, in addition to ethylene oxide, ethylene, oxygen, carbon dioxide, inert gases (nitrogen, argon, methane, ethane, etc.) and low boiling impurities such as formaldehyde produced in the ethylene oxidation reaction process, high boiling points such as acetaldehyde and acetic acid. The bottom liquid of the ethylene oxide absorption tower (2), in which a substantial amount of impurities were absorbed at the same time, is sent to the heat exchanger (20) through the conduit (19) and heat-exchanged with the bottom liquid of the ethylene oxide diffusion tower to raise the temperature to 105 ° C. , Conduit (2
It was sent to the gas-liquid separation tank (22) by 1), and the light separation gas containing a part of ethylene oxide and water was separated by the conduit (23). The remaining absorption liquid after flushing the light gas was passed through the conduit (24) to obtain a top pressure of 0.4 kg / cm 2 G and a temperature of 9
It is supplied to the upper part of the ethylene oxide stripping tower (25) at 9.6 ° C and heated through steam from the heater (30) of the ethylene oxide stripper (25) to dissipate 99% by weight or more of the ethylene oxide contained in the absorption liquid. From the bottom of the stripping tower (25), a part of the ethylene oxide stripping tower bottom liquid at a temperature of 114 ° C which does not substantially contain ethylene oxide is passed through the conduits (32) and (34) to the heat exchanger (20).
Heat exchange with the bottom liquid of the ethylene oxide absorption tower (2),
Cooling was carried out through the conduit (35) and further by cooling water (36) through which cooling water passed through the conduit (37), and then fresh water was introduced through the conduit (39) in order to adjust the ethylene glycol concentration in the absorption liquid. Low boiling point impurities such as by-produced ethylene glycol and formaldehyde, and high boiling points such as acetaldehyde and acetic acid, which are produced by the hydrolysis reaction of ethylene oxide and water in the absorption liquid between the oxidation step of oxidizing ethylene with molecular oxygen and the ethylene oxide emission step In order to prevent the increase of impurities, the bottom liquid of the ethylene oxide stripping column (25) was withdrawn from the bottom of the ethylene oxide stripping column (25) through conduits (32) and (33) and sent to a by-product ethylene glycol concentration step.
一方、エチレンオキシド放散塔（25）の塔頂部より放散
されるエチレンオキシドを含む放散蒸気は導管（26）を
通して、導管（28）に冷却水が通る凝縮器（27）へ送
り、凝縮液は導管（29）を通してエチレンオキシド放散
塔（25）の塔頂部へ還流し、未凝縮蒸気は導管（40）を
通して脱水塔（41）へ供給された。On the other hand, the vaporized vapor containing ethylene oxide that is diffused from the top of the ethylene oxide stripping tower (25) is sent through the conduit (26) to the condenser (27) through which the cooling water passes through the conduit (28), and the condensate is discharged through the conduit (29). ) To the top of the ethylene oxide stripping tower (25), and the uncondensed vapor was supplied to the dehydration tower (41) through the conduit (40).
また脱水塔（41）の加熱は直接、脱水塔（41）の下部へ
水蒸気を導入する加熱方式により加熱し、脱水塔（41）
の塔底より導管（50）を通して実質的にエチレンオキシ
ドを含まない水が抜き出された。The dehydration tower (41) is heated directly by a heating method in which steam is introduced into the lower part of the dehydration tower (41),
Water substantially free of ethylene oxide was extracted from the bottom of the column through the conduit (50).
脱水塔（41）の塔頂部よりエチレンオキシドを含む蒸気
は導管（42）を通して、導管（44）にブラインが通る凝
縮器（43）へ送り、凝縮液の一部は導管（46）を通して
脱水塔（41）の塔頂部へ還流し、凝縮器（43）の未凝縮
蒸気は導管（45）を通して再エチレンオキシド吸収塔
（図示していない）へ供給した。Vapor containing ethylene oxide is sent from the top of the dehydration tower (41) to the condenser (43) through which the brine passes through the conduit (44), and a part of the condensate flows through the conduit (46) to the dehydration tower ( It was refluxed to the top of 41), and the uncondensed vapor in the condenser (43) was supplied to the ethylene oxide absorption tower (not shown) through the conduit (45).
凝縮液の他部は導管（47）を通して軽質分分離塔（51）
へ供給した。The other part of the condensate is passed through the conduit (47) to the light separation column (51).
Supplied to.
軽質分分離塔（51）の加熱器（70）に、二酸化炭素放散
塔（12）の充填層（14）の下部から導管（15）により二
酸化炭素と水蒸気の混合蒸気を導入し、軽質分分離塔
（51）に熱量を与え、70℃まで混合蒸気は温度低下し
た。さらに軽質分分離塔（51）の加熱器（70）を出た混
合蒸気は導管（71）を通して、導管（73）に冷却水が冷
却器（72）に導き、水蒸気を凝縮分離した後、導管（7
4）より高純度二酸化炭素が得られた。導管（74）の二
酸化炭素中の不純物温度は乾燥二酸化炭素に対してエチ
レン、メタン、エタン等の炭化水素の合計量は0.1容量p
pm、酸素２容量ppmおよび窒素４容量ppmであった。A mixed vapor of carbon dioxide and water vapor is introduced into the heater (70) of the light separation column (51) through the conduit (15) from the lower part of the packed bed (14) of the carbon dioxide stripping tower (12) to separate the light fraction. Heat was applied to the tower (51), and the temperature of the mixed vapor decreased to 70 ° C. Further, the mixed vapor discharged from the heater (70) of the light fraction separation column (51) passes through the conduit (71), the cooling water is guided to the cooler (72) through the conduit (73), and the steam is condensed and separated. (7
4) Higher purity carbon dioxide was obtained. The impurity temperature of carbon dioxide in the conduit (74) is dry carbon dioxide, and the total amount of hydrocarbons such as ethylene, methane and ethane is 0.1 volume p.
pm, 2 ppm by volume of oxygen and 4 ppm by volume of nitrogen.
軽質分分離塔（41）の塔頂部より軽質分ガスを含むエチ
レンオキシド蒸気は導管（52）を通して凝縮器（53）へ
送り、凝縮液は導管（56）を通して軽質分分離塔（51）
の塔頂部へ還流し、未凝縮蒸気は導管（55）を通してエ
チレンオキシドを回収するため再エチレンオキシド吸収
塔（図示してない）へ供給した。軽質分分離塔851）の
塔底液は導管（59）を通してエチレンオキシド精留塔
（60）へ供給した。From the top of the light fraction separation column (41), ethylene oxide vapor containing light fraction gas is sent to the condenser (53) through the conduit (52), and the condensate is passed through the conduit (56) to the light fraction separation column (51).
Was refluxed to the top of the column and uncondensed vapor was fed to a re-ethylene oxide absorption column (not shown) for recovering ethylene oxide through a conduit (55). The bottom liquid of the light fraction separation column 851) was supplied to the ethylene oxide rectification column (60) through a conduit (59).
エチレンオキシド精留塔（60）の加熱器（67）により水
蒸気で導管（68）を通して加熱する方式により加熱し、
エチレンオキシド精留塔（60）の塔底温度60℃、エチレ
ンオキシド精留塔底圧力3.2kg/cm2Gで精留を行ない、エ
チレンオキシド精留塔より塔頂温度51℃、塔頂部圧力3.
0kg/cm2Gのエチレンオキシド蒸気を導管（61）を通し
て、エチレンオキシド凝縮器（62）へ送り、エチレンオ
キシドを液化し、一部は導管（65）を通してエチレンオ
キシド精留塔（60）の塔頂部へ還流液として供給し、他
部は導管（66）を通してエチレンオキシド製品として抜
き出した。The ethylene oxide rectification column (60) is heated by a heater (67) with steam through a conduit (68).
The ethylene oxide rectification column (60) has a bottom temperature of 60 ° C. and an ethylene oxide rectification column bottom pressure of 3.2 kg / cm 2 G for rectification. The ethylene oxide rectification column has a top temperature of 51 ° C. and a top pressure of 3.
0 kg / cm 2 G ethylene oxide vapor is sent to the ethylene oxide condenser (62) through the conduit (61) to liquefy ethylene oxide, and part of it is refluxed to the top of the ethylene oxide rectification column (60) through the conduit (65). The other part was withdrawn as an ethylene oxide product through the conduit (66).
エチレンオキシド凝縮器（62）の未凝縮蒸気は導管（6
4）を通してエチレンオキシドを回収するため再エチレ
ンオキシド吸収塔（図示してない）へ供給した。The uncondensed vapor in the ethylene oxide condenser (62) is
It was fed to a re-ethylene oxide absorption tower (not shown) to recover ethylene oxide through 4).
エチレンオキシド精留塔（60）の塔底液はアセトアルデ
ヒド、水および酢酸等の高沸点不純物の重質分分離のた
め必要により導管（69）を通して抜き出された。The bottom liquid of the ethylene oxide rectification column (60) was withdrawn through a conduit (69) as necessary for the separation of heavy components such as acetaldehyde, water and acetic acid having high boiling points.
表−１にこのプロセスの連続操作条件を一括して表示す
る。Table 1 shows the continuous operating conditions of this process all together.
比較例１ 図−２においてエチレンを銀触媒の存在下、分子状酸素
含有ガスにより接触気相酸化して生成するエチレンオキ
シドを含む反応生成ガスを導管（１）を通して、充填塔
あるいは棚段塔形式のエチレンオキシド吸収塔（２）の
下部へ供給し、導管（３）よりエチレンオキシド吸収塔
（２）の上部へ吸収液を導入し、反応生成ガスと向流接
触させ、反応生成ガス中の99重量％以上のエチレンオキ
シドを回収し、エチレンオキシド吸収塔（２）の塔頂よ
り吸収しなかったエチレン、酸素、二酸化炭素、不活性
ガス（窒素、アルゴン、メタン、エタン）、アルデヒ
ド、酸性物質等のガスは導管（４）を通して二酸化炭素
吸収工程および／または酸化反応工程へ循環した。この
吸収工程においてエチレンオキシドの他、エチレン、酸
素、二酸化炭素、不活性ガス（窒素、アルゴン、メタ
ン、エタン、）ならびにエチレン酸化反応工程で生成し
たホルムアルデヒド等の低沸点不純物、アセトアルデヒ
ド、酢酸等の高沸点不純物もその実質量が同時に吸収さ
れ、エチレンオキシド吸収塔（２）の塔底液を導管（1
9）を通して熱交換器（20）へ送りエチレンオキシド放
散塔底液と熱交換して温度105℃に高め、導管（21）に
より気液分離タンク（22）へ送られ一部エチレンオキシ
ドを含む軽質分ガスが導管（23）により分離した、軽質
分ガスをフラッシュした残部の吸収液を導管（24）を通
して塔頂圧力0.4Kg/cm2G、温度99.6℃のエチレンオキシ
ド放散塔（25）の上部へ供給し、エチレンオキシド放散
塔（25）の加熱器（30）より水蒸気により加熱し、吸収
液中に含まれるエチレンオキシドの99重量％以上を放散
せしめ、エチレンオキシド放散塔（25）の底部よりエチ
レンオキシドを実質的に含まない温度114℃のエチレン
オキシド放散塔底液の一部は導管（32）および導管（3
4）を通して熱交換器（20）でエチレンオキシド吸収塔
（２）の塔底液と熱交換し、導管（35）を通して、さら
に導管（37）に冷却水が通る冷却器（36）により冷却
し、ついで吸収液中のエチレングリコール温度を調節す
るため新鮮な水を導管（39）を通して導入した。エチレ
ンを分子状酸素で酸化する酸化工程およびエチレンオキ
シド放散工程の間で吸収液中にエチレンオキシドと水と
の加水反応で生成する副生エチレングリコールおよびホ
ルムアルデヒド等の低沸点不純物、アセトアルデヒドお
よび酢酸等の高沸点不純物の増加を防ぐためエチレンオ
キシド放散塔（25）の塔底より導管（32）および（33）
を通してエチレンオキシド放散塔（25）の底液を抜き出
し、副生エチレングリコール濃縮工程に送った。Comparative Example 1 In FIG. 2, a reaction product gas containing ethylene oxide produced by catalytic gas-phase oxidation of ethylene with a molecular oxygen-containing gas in the presence of a silver catalyst is passed through a conduit (1) to form a packed column or a plate column. Supply to the lower part of the ethylene oxide absorption tower (2), introduce the absorption liquid to the upper part of the ethylene oxide absorption tower (2) through the conduit (3), make countercurrent contact with the reaction product gas, and 99% by weight or more of the reaction product gas Of ethylene oxide, which was not absorbed from the top of the ethylene oxide absorption tower (2), such as ethylene, oxygen, carbon dioxide, inert gases (nitrogen, argon, methane, ethane), aldehydes, acidic substances, etc. It was circulated through 4) to the carbon dioxide absorption step and / or the oxidation reaction step. In this absorption process, in addition to ethylene oxide, ethylene, oxygen, carbon dioxide, inert gases (nitrogen, argon, methane, ethane, etc.) and low boiling impurities such as formaldehyde produced in the ethylene oxidation reaction process, high boiling points such as acetaldehyde and acetic acid. A substantial amount of impurities are absorbed at the same time, and the bottom liquid of the ethylene oxide absorption tower (2) is introduced into the conduit (1
It is sent to the heat exchanger (20) through 9) and exchanges heat with the bottom liquid of the ethylene oxide stripping tower to raise the temperature to 105 ° C, and is sent to the gas-liquid separation tank (22) through the conduit (21) and a light fraction gas partially containing ethylene oxide. Was separated by the conduit (23) and the remaining absorption liquid after flashing the light gas was supplied to the upper part of the ethylene oxide stripping tower (25) at a column top pressure of 0.4 kg / cm 2 G and a temperature of 99.6 ° C through the conduit (24). , Heated by steam from the heater (30) of the ethylene oxide diffusion tower (25) to disperse 99% by weight or more of ethylene oxide contained in the absorption liquid, and substantially contain ethylene oxide from the bottom of the ethylene oxide diffusion tower (25) Part of the bottom liquid of the ethylene oxide stripping tower, which has a temperature of 114 ° C, is
Heat exchange with the bottom liquid of the ethylene oxide absorption tower (2) in the heat exchanger (20) through 4) and cooling by the cooler (36) through which the cooling water passes through the conduit (35) and further through the conduit (37), Fresh water was then introduced through conduit (39) to control the temperature of ethylene glycol in the absorbent. Low boiling point impurities such as by-produced ethylene glycol and formaldehyde, and high boiling points such as acetaldehyde and acetic acid, which are produced by the hydrolysis reaction of ethylene oxide and water in the absorption liquid between the oxidation step of oxidizing ethylene with molecular oxygen and the ethylene oxide emission step Conduit (32) and (33) from the bottom of the ethylene oxide stripping tower (25) to prevent the increase of impurities
The bottom liquid of the ethylene oxide stripping tower (25) was withdrawn through and sent to the by-product ethylene glycol concentration step.
一方、エチレンオキシド放散塔（25）の塔頂部より放散
されるエチレンオキシドを含む放散蒸気は導管（26）を
通して、導管（28）に冷却水が通る凝縮器（27）へ送
り、凝縮器（27）へ送り、凝縮液は導管（29）を通して
エチレンオキシド放散塔（25）の塔頂部へ還流し、未凝
縮蒸気は導管（40）を通して脱水塔（41）へ供給した。On the other hand, the emitted vapor containing ethylene oxide which is emitted from the top of the ethylene oxide diffusion tower (25) is sent to the condenser (27) through which the cooling water passes through the conduit (28) and then to the condenser (27). The sent condensate was refluxed to the top of the ethylene oxide stripping tower (25) through the conduit (29), and the uncondensed vapor was supplied to the dehydration tower (41) through the conduit (40).
また脱水塔（41）の加熱は直接脱水塔（41）の下部へ水
蒸気を導入する加熱方式により加熱し、脱水塔（41）の
塔底より導管（50）を通してエチレンオキシドを含まな
い水が抜き出された。The dehydration tower (41) is heated by a heating method in which steam is directly introduced into the lower part of the dehydration tower (41), and water free of ethylene oxide is extracted from the bottom of the dehydration tower (41) through a conduit (50). Was done.
脱水塔（41）の塔頂部よりエチレンオキシドを含む蒸気
は導管（42）を通して、導管（44）にブラインが通る凝
縮器（43）へ送り、凝縮液の一部は導管（46）を通して
脱水塔（41）の塔頂部へ還流し、凝縮器（43）の未凝縮
蒸気は導管（45）を通して再エチレンオキシド吸収塔
（図示しない）へ供給した。Vapor containing ethylene oxide is sent from the top of the dehydration tower (41) to the condenser (43) through which the brine passes through the conduit (44), and a part of the condensate flows through the conduit (46) to the dehydration tower ( It was refluxed to the top of 41), and the uncondensed vapor in the condenser (43) was supplied to a re-ethylene oxide absorption tower (not shown) through the conduit (45).
凝縮器（43）の凝縮液の他部は導管（47）を通して軽質
分分離塔（51）へ供給された。The other part of the condensate of the condenser (43) was supplied to the light fraction separation column (51) through the conduit (47).
軽質分分離塔（51）の加熱器（57）により水蒸気を導管
（58）を通して加熱する方式により加熱し、軽質分分離
塔（51）の塔頂部より軽質分を含むエチレンオキシド蒸
気は導管（52）を通して凝縮器（53）へ送り、凝縮液は
導管（56）を通して軽質分分離塔（51）の塔頂部へ還流
し、未凝縮蒸気は導管（55）を通してエチレンオキシド
を回収するため再エチレンオキシド吸収塔（図示してな
い）へ供給された。Steam is heated by the heater (57) of the light fraction separation column (51) through the conduit (58), and ethylene oxide vapor containing light components is introduced from the top of the light fraction separation column (51) into the conduit (52). To the condenser (53) through the conduit (56) to reflux to the top of the light fraction separation column (51), and the uncondensed vapor through the conduit (55) to recover ethylene oxide and the ethylene oxide absorption tower ( (Not shown).
軽質分分離塔（51）の塔底より導管（59）を通してエチ
レンオキシド精留塔（60）へ供給された。It was supplied to the ethylene oxide rectification column (60) through the conduit (59) from the bottom of the light fraction separation column (51).
エチレンオキシド精留塔（60）の加熱器（67）により水
蒸気を導管（68）を通して加熱する方式により加熱し、
エチレンオキシド精留塔（60）の加熱器（67）へ導管
（68）より圧力2.2kg/cm2Gの水蒸気を供給し、エチレン
オキシド精留塔（60）の塔底温度60℃、エチレンオキシ
ド精留塔底圧力3.2kg/cm2Gで精留を行ない、エチレンオ
キシド精留塔頂より塔頂温度51℃、塔頂圧力3.0kg/cm2G
のエチレンオキシド蒸気を導管（61）を通して、凝縮器
（62）へ送りエチレンオキシド蒸気は液化し、液化した
一部は導管（65）を通してエチレンオキシド精留塔（6
0）の塔頂部へ還流液として導入し、液化した他部は導
管（66）を通してエチレンオキシド製品として抜き出さ
れた。The steam is heated by the heater (67) of the ethylene oxide rectification tower (60) through the conduit (68),
Steam of pressure 2.2 kg / cm 2 G is supplied from the conduit (68) to the heater (67) of the ethylene oxide rectification column (60), the bottom temperature of the ethylene oxide rectification column (60) is 60 ° C, and the ethylene oxide rectification column is Rectification is carried out at a bottom pressure of 3.2 kg / cm 2 G, a top temperature of 51 ° C from the top of the ethylene oxide rectification column, and a top pressure of 3.0 kg / cm 2 G
Of the ethylene oxide vapor is sent to the condenser (62) through the conduit (61), the ethylene oxide vapor is liquefied, and a part of the liquefied ethylene oxide vapor is passed through the conduit (65) to the ethylene oxide rectification column (6
It was introduced as a reflux liquid into the top of column 0), and the other liquefied portion was withdrawn as an ethylene oxide product through a conduit (66).
エチレンオキシド精留塔（60）の凝縮器（62）の未凝縮
蒸気は導管（64）を通してエチレンオキシドを回収する
ため再エチレンオキシド吸収塔（図示してない）へ供給
された。The uncondensed vapor in the condenser (62) of the ethylene oxide rectification column (60) was fed through a conduit (64) to a re-ethylene oxide absorption column (not shown) to recover ethylene oxide.
エチレンオキシド精留塔（60）の塔底液はアセトアルデ
ヒド、水および酢酸等の高沸点不純物の重質分分離のた
め必要により導管（69）を通して抜き出された。The bottom liquid of the ethylene oxide rectification column (60) was withdrawn through a conduit (69) as necessary for the separation of heavy components such as acetaldehyde, water and acetic acid having high boiling points.
表−２にこのプロセスの連続操作条件を一括して表示す
る。Table 2 shows the continuous operating conditions of this process all together.
このプロセスにおいて、二酸化炭素放散塔（12）の塔頂
蒸気は導管（13）を通して、導管（77）に冷却水が通る
凝縮器（76）へ送られ、同伴している水蒸気は凝縮分離
し、少量の水を同伴している二酸化炭素は、導管（79）
を通して得られた。このガスの組成は、乾燥二酸化炭素
に対してエチレン3000容量ppm、メタン3500容量ppm、酸
素4000容量ppmであった。In this process, the overhead vapor of the carbon dioxide stripping column (12) is sent through a conduit (13) to a condenser (76) through which cooling water passes through a conduit (77), and the accompanying water vapor is condensed and separated. Carbon dioxide accompanied by a small amount of water, conduit (79)
Obtained through. The composition of this gas was 3000 vol ppm of ethylene, 3500 vol ppm of methane, and 4000 vol ppm of oxygen with respect to dry carbon dioxide.
（発明の効果） 本発明の方法によれば、二酸化炭素放散塔の中段より、
ガスを抜き出すことにより高純度二酸化炭素を取得する
ことが可能になり、同時にエチレンオキシド精製工程中
の軽質分分離塔の加熱に要する外部からの加熱蒸気を大
幅に減少することができる効果を有するものである。 (Effect of the invention) According to the method of the present invention, from the middle stage of the carbon dioxide stripping tower,
By extracting the gas, it becomes possible to obtain high-purity carbon dioxide, and at the same time, it has the effect of significantly reducing the heating steam from the outside required for heating the light fraction separation column during the ethylene oxide purification process. is there.
図−１は、本発明のエチレンオキシド精留方法の好まし
い具体例を示す一例である。 図−２は、本発明に関連する公知のエチレンオキシド精
留方法を示す一例である。 （２）……エチレンオキシド吸収塔 （20）……熱交換器 （７）……二酸化炭素吸収塔 （10）……反応器、 （12）……二酸化炭素放散塔 （17）……二酸化炭素放散塔加熱器 （22）……気液分離タンク （25）……エチレンオキシド放散器 （30）……エチレンオキシド放散塔加熱器 （36）……吸収液冷却器 （27）……エチレンオキシド放散塔凝縮器 （41）……脱水塔 （48）……脱水塔加熱器 （43）……脱水塔凝縮器 （51）……軽質分分離塔 （57）……軽質分分離塔加熱器 （53）……軽質分分離塔凝縮器 （60）……エチレンオキシド精留塔 （67）……エチレンオキシド精留塔加熱器 （62）……エチレンオキシド精留塔凝縮器 （70）……軽質分分離塔加熱器 （76）……二酸化炭素放散塔凝縮器FIG. 1 is an example showing a preferred specific example of the ethylene oxide rectification method of the present invention. FIG. 2 is an example showing a known ethylene oxide rectification method related to the present invention. (2) …… Ethylene oxide absorption tower (20) …… Heat exchanger (7) …… Carbon dioxide absorption tower (10) …… Reactor, (12) …… Carbon dioxide emission tower (17) …… Carbon dioxide emission Tower heater (22) …… Gas-liquid separation tank (25) …… Ethylene oxide diffuser (30) …… Ethylene oxide diffuser heater (36) …… Absorption liquid cooler (27) …… Ethylene oxide diffuser condenser ( 41) …… Dehydration tower (48) …… Dehydration tower heater (43) …… Dehydration tower condenser (51) …… Light fraction separation tower (57) …… Light fraction separation tower heater (53) …… Light fraction Separation tower condenser (60) …… Ethylene oxide rectification tower (67) …… Ethylene oxide rectification tower heater (62) …… Ethylene oxide rectification tower condenser (70) …… Light fraction separation tower heater (76) ...... Carbon dioxide emission tower condenser
Claims (1)
有ガスと接触気相酸化して生成したエチレンオキシドを
含有する反応生成ガスをエチレンオキシド吸収塔へ導入
し吸収液と向流接触させ、エチレンオキシド吸収塔頂部
よりのガスの一部はエチレン酸化反応工程へ循環し、該
エチレンオキシド吸収塔頂部よりのガスの一部を二酸化
炭素吸収塔へ導き、アルカリ性吸収液と向流接触させて
二酸化炭素をアルカリ性吸収液に吸収せしめたアルカリ
性吸収液を二酸化炭素放散塔へ導き、二酸化炭素を放散
分離し、該エチレンオキシド吸収塔のエチレンオキシド
吸収塔底液はエチレンオキシド放散塔へ供給し、エチレ
ンオキシド放散塔頂からのガスは凝縮液と未凝縮ガスに
分離して未凝縮ガスは脱水塔へ供給し、脱水塔底部より
水分を分離し、脱水塔頂からのガスは凝縮液と未凝縮ガ
スに分離し、凝縮液の一部は加熱器を備えた軽質分分離
塔に供給する工程において、二酸化炭素吸収塔底液を二
酸化炭素放散塔の気液接触部上へ供給し、フラッシュし
た放散ガスは分離し、該気液接触部より下に設けられた
気相部より放散される放散ガスを軽質分分離塔の加熱器
の加熱源に使用した後、二酸化炭素を回収することを特
徴とする高純度二酸化炭素の回収方法。1. A reaction product gas containing ethylene oxide produced by catalytic vapor-phase oxidation of ethylene with a molecular oxygen-containing gas in the presence of a silver catalyst is introduced into an ethylene oxide absorption tower and countercurrently contacted with the absorbing liquid to obtain ethylene oxide. Part of the gas from the top of the absorption tower is circulated to the ethylene oxidation reaction step, and part of the gas from the top of the ethylene oxide absorption tower is introduced to the carbon dioxide absorption tower, and the carbon dioxide is alkalinized by making countercurrent contact with the alkaline absorption liquid. The alkaline absorption liquid absorbed in the absorption liquid is introduced into a carbon dioxide stripping tower, carbon dioxide is stripped and separated, the ethylene oxide absorption tower bottom liquid of the ethylene oxide absorption tower is supplied to the ethylene oxide stripping tower, and the gas from the ethylene oxide stripping tower top is It is separated into condensate and uncondensed gas, and the uncondensed gas is supplied to the dehydration tower. The gas from the top of the tower is separated into condensate and uncondensed gas, and part of the condensate is supplied to the light fractionation tower equipped with a heater. The flash gas that was supplied to the liquid contact part and was flashed was separated, and the gas that was diffused from the gas phase part provided below the gas-liquid contact part was used as the heating source of the heater of the light separation column. After that, a method for recovering high-purity carbon dioxide, which comprises recovering carbon dioxide.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62001822A JPH0676205B2 (en) | 1987-01-09 | 1987-01-09 | High-purity carbon dioxide recovery method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62001822A JPH0676205B2 (en) | 1987-01-09 | 1987-01-09 | High-purity carbon dioxide recovery method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS63170206A JPS63170206A (en) | 1988-07-14 |
| JPH0676205B2 true JPH0676205B2 (en) | 1994-09-28 |
Family
ID=11512253
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62001822A Expired - Fee Related JPH0676205B2 (en) | 1987-01-09 | 1987-01-09 | High-purity carbon dioxide recovery method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0676205B2 (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE4417830C1 (en) * | 1994-05-20 | 1995-10-19 | Linde Ag | Production of high-purity carbon dioxide |
| JP5687917B2 (en) * | 2011-02-16 | 2015-03-25 | 株式会社日本触媒 | Method for purifying ethylene oxide |
| JP5828793B2 (en) * | 2012-03-30 | 2015-12-09 | 株式会社日本触媒 | Method for recovering carbon dioxide in ethylene oxide production process |
| JP6391913B2 (en) * | 2013-03-29 | 2018-09-19 | 株式会社日本触媒 | Method for producing ethylene oxide |
| JP6174352B2 (en) * | 2013-03-29 | 2017-08-02 | 株式会社日本触媒 | Method for producing ethylene oxide |
| JP6117027B2 (en) | 2013-07-04 | 2017-04-19 | 株式会社神戸製鋼所 | Absorption method and apparatus using fine flow path |
| US11618739B2 (en) | 2018-08-10 | 2023-04-04 | Nippon Shokubai Co., Ltd. | Method of producing ethylene oxide and ethylene glycol |
| CN115461127B (en) * | 2020-05-01 | 2024-07-30 | 东邦瓦斯株式会社 | Carbon dioxide recovery device |
-
1987
- 1987-01-09 JP JP62001822A patent/JPH0676205B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS63170206A (en) | 1988-07-14 |
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