CN114436745B - Method and device for preparing polymerization grade ethylene by dry gas - Google Patents
Method and device for preparing polymerization grade ethylene by dry gas Download PDFInfo
- Publication number
- CN114436745B CN114436745B CN202011216776.9A CN202011216776A CN114436745B CN 114436745 B CN114436745 B CN 114436745B CN 202011216776 A CN202011216776 A CN 202011216776A CN 114436745 B CN114436745 B CN 114436745B
- Authority
- CN
- China
- Prior art keywords
- tower
- demethanizer
- temperature
- absorption
- operating pressure
- 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.)
- Active
Links
- 239000005977 Ethylene Substances 0.000 title claims abstract description 87
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 title claims abstract description 86
- 238000000034 method Methods 0.000 title claims abstract description 54
- 238000006116 polymerization reaction Methods 0.000 title claims abstract description 23
- 238000010521 absorption reaction Methods 0.000 claims abstract description 99
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 83
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 83
- 238000003795 desorption Methods 0.000 claims abstract description 57
- 238000011282 treatment Methods 0.000 claims abstract description 39
- 238000000926 separation method Methods 0.000 claims abstract description 19
- 229920000642 polymer Polymers 0.000 claims abstract description 6
- 239000006096 absorbing agent Substances 0.000 claims description 26
- 239000007791 liquid phase Substances 0.000 claims description 14
- 239000012071 phase Substances 0.000 claims description 11
- 238000001816 cooling Methods 0.000 claims description 7
- 238000005191 phase separation Methods 0.000 claims description 3
- 208000016261 weight loss Diseases 0.000 claims 2
- 230000004580 weight loss Effects 0.000 claims 2
- 238000005265 energy consumption Methods 0.000 abstract description 12
- 239000007789 gas Substances 0.000 description 86
- 230000009102 absorption Effects 0.000 description 82
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 42
- 239000002250 absorbent Substances 0.000 description 39
- 230000002745 absorbent Effects 0.000 description 39
- 238000010438 heat treatment Methods 0.000 description 12
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 11
- OTMSDBZUPAUEDD-UHFFFAOYSA-N Ethane Chemical compound CC OTMSDBZUPAUEDD-UHFFFAOYSA-N 0.000 description 10
- 239000001257 hydrogen Substances 0.000 description 10
- 229910052739 hydrogen Inorganic materials 0.000 description 10
- 238000011084 recovery Methods 0.000 description 10
- 238000007670 refining Methods 0.000 description 9
- 239000000463 material Substances 0.000 description 8
- 230000006835 compression Effects 0.000 description 7
- 238000007906 compression Methods 0.000 description 7
- 230000000694 effects Effects 0.000 description 7
- 125000004432 carbon atom Chemical group C* 0.000 description 6
- 150000002431 hydrogen Chemical class 0.000 description 6
- 239000000203 mixture Substances 0.000 description 6
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 5
- 238000000605 extraction Methods 0.000 description 5
- 238000004519 manufacturing process Methods 0.000 description 5
- 229910052757 nitrogen Inorganic materials 0.000 description 5
- ATUOYWHBWRKTHZ-UHFFFAOYSA-N Propane Chemical compound CCC ATUOYWHBWRKTHZ-UHFFFAOYSA-N 0.000 description 4
- 238000001035 drying Methods 0.000 description 4
- 230000009103 reabsorption Effects 0.000 description 4
- 238000005406 washing Methods 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- 238000009825 accumulation Methods 0.000 description 3
- 239000002253 acid Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000002737 fuel gas Substances 0.000 description 3
- 239000003502 gasoline Substances 0.000 description 3
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 description 3
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 description 3
- 239000003381 stabilizer Substances 0.000 description 3
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 description 2
- OFBQJSOFQDEBGM-UHFFFAOYSA-N Pentane Chemical compound CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 description 2
- NNPPMTNAJDCUHE-UHFFFAOYSA-N isobutane Chemical compound CC(C)C NNPPMTNAJDCUHE-UHFFFAOYSA-N 0.000 description 2
- QWTDNUCVQCZILF-UHFFFAOYSA-N isopentane Chemical compound CCC(C)C QWTDNUCVQCZILF-UHFFFAOYSA-N 0.000 description 2
- YWAKXRMUMFPDSH-UHFFFAOYSA-N pentene Chemical compound CCCC=C YWAKXRMUMFPDSH-UHFFFAOYSA-N 0.000 description 2
- 239000001294 propane Substances 0.000 description 2
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 description 2
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 description 2
- 238000004064 recycling Methods 0.000 description 2
- 231100000987 absorbed dose Toxicity 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 238000004523 catalytic cracking Methods 0.000 description 1
- 238000004517 catalytic hydrocracking Methods 0.000 description 1
- 239000003518 caustics Substances 0.000 description 1
- 238000012824 chemical production Methods 0.000 description 1
- IAQRGUVFOMOMEM-ARJAWSKDSA-N cis-but-2-ene Chemical compound C\C=C/C IAQRGUVFOMOMEM-ARJAWSKDSA-N 0.000 description 1
- 238000004939 coking Methods 0.000 description 1
- 238000010668 complexation reaction Methods 0.000 description 1
- 230000001808 coupling effect Effects 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 238000006392 deoxygenation reaction Methods 0.000 description 1
- 238000006477 desulfuration reaction Methods 0.000 description 1
- 230000023556 desulfurization Effects 0.000 description 1
- AFABGHUZZDYHJO-UHFFFAOYSA-N dimethyl butane Natural products CCCC(C)C AFABGHUZZDYHJO-UHFFFAOYSA-N 0.000 description 1
- 229910001873 dinitrogen Inorganic materials 0.000 description 1
- 230000005611 electricity Effects 0.000 description 1
- 239000001282 iso-butane Substances 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 238000000197 pyrolysis Methods 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 238000005201 scrubbing Methods 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 238000004227 thermal cracking Methods 0.000 description 1
- IAQRGUVFOMOMEM-ONEGZZNKSA-N trans-but-2-ene Chemical compound C\C=C\C IAQRGUVFOMOMEM-ONEGZZNKSA-N 0.000 description 1
- 238000010977 unit operation Methods 0.000 description 1
- 239000002918 waste heat Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C7/00—Purification; Separation; Use of additives
- C07C7/005—Processes comprising at least two steps in series
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C7/00—Purification; Separation; Use of additives
- C07C7/04—Purification; Separation; Use of additives by distillation
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C7/00—Purification; Separation; Use of additives
- C07C7/11—Purification; Separation; Use of additives by absorption, i.e. purification or separation of gaseous hydrocarbons with the aid of liquids
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Analytical Chemistry (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Water Supply & Treatment (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
The invention relates to the technical field of dry gas separation, and discloses a method and a device for preparing polymer grade ethylene from dry gas. The method mainly comprises the following steps: (1) Introducing dry gas into an absorption tower for absorption treatment to obtain a tower kettle product containing two or more components; (2) Introducing the tower bottom product of the absorption tower into a demethanizer for demethanization treatment to further obtain a tower bottom product containing two or more components; (3) Introducing a tower bottom product of the demethanizer into a desorption tower for desorption treatment so as to obtain crude carbon two components from the top of the desorption tower; (4) Introducing the crude carbon bi-component obtained from the top of the desorption tower into a de-heavy tower for de-heavy treatment so as to obtain purified carbon bi-component from the top of the de-heavy tower; (5) Introducing the purified carbon two components obtained from the top of the heavy-removal tower into an ethylene rectifying tower for separation treatment to obtain the polymerization-grade ethylene. The method for preparing the polymerization grade ethylene by using the dry gas has the advantage of low energy consumption.
Description
Technical Field
The invention relates to the technical field of dry gas separation, in particular to a method and a device for preparing polymer grade ethylene from dry gas.
Background
In the course of oil refining and chemical production a large quantity of dry gas can be produced, for example in the processes of catalytic cracking, thermal cracking, delayed coking and hydrocracking, and the produced dry gas mainly contains hydrogen gas, methane, ethylene, ethane and nitrogen gas, in addition to small quantity of C three, C four and C five fractions and trace quantity of C six and above components. If ethylene and ethane in the refinery dry gas are recovered, a large amount of pyrolysis raw oil can be saved, so that the ethylene production cost is greatly reduced, and the enterprises obtain better economic benefits.
The existing methods for recycling ethylene from refinery dry gas mainly comprise a cryogenic separation method, an oil absorption method, a complexation separation method, a pressure swing adsorption method and the like, and the methods generally have the problems of complex flow, high energy consumption and large investment.
CN109912379a discloses a method and apparatus for separating refinery dry gas, the process comprises steps of compression, absorption, desorption, purification, demethanization, ethylene rectification, etc., and has the advantages of low cost of absorbent, high recovery rate, etc. However, the energy consumption of the method is still relatively high, and the energy coupling effect and the carbon two recovery rate are still to be further improved.
Therefore, it is needed to provide a method and a device for preparing polymer grade ethylene by dry gas, which have the advantages of simple flow, low investment, low energy consumption and high recovery rate of carbon two.
Disclosure of Invention
The invention aims to solve the problems of complex flow, large investment and high energy consumption of the dry gas polymerization grade ethylene in the prior art, and provides a method and a device for preparing the polymerization grade ethylene by using the dry gas.
In order to achieve the above object, the present invention provides in one aspect a method for producing polymerization grade ethylene from dry gas, the method comprising the steps of:
(1) Introducing dry gas into an absorption tower for absorption treatment to obtain a tower kettle product containing two or more components;
(2) Introducing a tower bottom product of the absorption tower into a demethanizer for demethanization so as to further obtain a tower bottom product containing two or more components, wherein the operating pressure of the demethanizer is lower than that of the absorption tower;
(3) Introducing a tower bottom product of the demethanizer into a desorption tower for desorption treatment so as to obtain crude carbon two components from the top of the desorption tower;
(4) Introducing the crude carbon bi-component obtained from the top of the desorption tower into a de-heavy tower for de-heavy treatment so as to obtain purified carbon bi-component from the top of the de-heavy tower;
(5) Introducing the purified carbon two components obtained from the top of the heavy-removal tower into an ethylene rectifying tower for separation treatment to obtain the polymerization-grade ethylene.
In a second aspect, the invention provides an apparatus for dry gas polymerization grade ethylene, the apparatus comprising: the absorption tower is used for carrying out absorption treatment on the dry gas to obtain a tower kettle product containing two or more components;
The demethanizer is used for carrying out demethanization treatment on the tower bottom product of the absorber so as to further obtain the tower bottom product containing two or more components;
The desorber is used for carrying out desorption treatment on a tower kettle product of the demethanizer so as to obtain crude carbon two components from the top of the desorber;
the heavy-removal tower is used for carrying out heavy-removal treatment on the crude carbon bi-component obtained from the top of the desorption tower so as to obtain purified carbon bi-component from the top of the heavy-removal tower;
and the ethylene rectifying tower is used for separating the purified carbon two components obtained from the top of the heavy-removal tower to obtain the polymerization-grade ethylene.
Through the technical scheme, the invention has the following beneficial technical effects:
1, by arranging the absorption tower and the demethanizer, the pressure requirement of the demethanizing process is reduced, the demethanizing can be realized at the pressure lower than 3.3MPa, and the yield and purity of the product of the polymerization grade ethylene are ensured. Under the low pressure condition, only the tower bottom material flow of the desorption tower can be used as a heat source of a tower bottom reboiler of the demethanizer, so that the consumption of steam is saved;
2, according to the preferred embodiment of the invention, the tower bottom product of the desorption tower is used as a heating source of a tower bottom reboiler of the demethanizer, a tower top heat exchanger of the absorption tower and a tower bottom reboiler of the ethylene rectifying tower, so that the heat utilization rate is further improved, and the energy consumption in the production process of the polymerization grade B is reduced;
3, according to the preferred embodiment of the invention, the recovery rate of the carbon two components is further improved by arranging the balance tank;
4, according to a preferred embodiment of the present invention, the recovery rate of the polymerization grade ethylene can be up to 99% or more, and the ethylene purity is about 99.96%;
Drawings
FIG. 1 is a flow chart of a dry gas separation process according to a preferred embodiment of the present invention;
FIG. 2 is a flow chart of a dry gas separation process according to a preferred embodiment of the present invention;
fig. 3 is a flow chart of the dry gas separation process in comparative example 1.
Detailed Description
The endpoints and any values of the ranges disclosed herein are not limited to the precise range or value, and are understood to encompass values approaching those ranges or values. For numerical ranges, one or more new numerical ranges may be found between the endpoints of each range, between the endpoint of each range and the individual point value, and between the individual point value, in combination with each other, and are to be considered as specifically disclosed herein.
In a first aspect the present invention provides a process for dry gas polymerization grade ethylene comprising the steps of:
(1) Introducing dry gas into an absorption tower for absorption treatment to obtain a tower kettle product containing two or more components;
(2) Introducing a tower bottom product of the absorption tower into a demethanizer for demethanization so as to further obtain a tower bottom product containing two or more components, wherein the operating pressure of the demethanizer is lower than that of the absorption tower;
(3) Introducing a tower bottom product of the demethanizer into a desorption tower for desorption treatment so as to obtain crude carbon two components from the top of the desorption tower;
(4) Introducing the crude carbon bi-component obtained from the top of the desorption tower into a de-heavy tower for de-heavy treatment so as to obtain purified carbon bi-component from the top of the de-heavy tower;
(5) Introducing the purified carbon two components obtained from the top of the heavy-removal tower into an ethylene rectifying tower for separation treatment to obtain the polymerization-grade ethylene.
In the step (1), the step of (a),
In a preferred embodiment, the dry gas is introduced into the absorption column after compression and cooling, wherein the pressure of the compressed dry gas is 2-5.2MPa, preferably 2.8-4.3MPa; the temperature of the cooled dry gas is 1-30deg.C, preferably 15-20deg.C.
The pressure of the dry gas is generally required to be increased step by step, the number of the compressor sections is not particularly limited, and the method can be applied to the method in any operation capable of increasing the pressure of the dry gas to 2-5.2 MPa. Preferably, after compression, the outlet temperature of each section of dry gas does not exceed 120 ℃.
In a preferred embodiment, the absorbent used in the absorber contains carbon three, carbon four, carbon five, carbon six and above fractions, wherein the molar content of the carbon six and above fractions is 0-10%, preferably 0-5%, more preferably 0-2%.
Wherein the absorbent is used for absorbing the two or more fractions of carbon in the dry gas. In the present invention, the specific composition of each fraction in the absorbent is not particularly limited, and for example, carbon three may be selected from propane and/or propylene, carbon four may be selected from at least one of n-butane, isobutane, 1-butene, trans-2-butene, cis-2-butene, and carbon five may be selected from at least one of n-pentane, isopentane, and 1-pentene. The specific contents of carbon three, carbon four and carbon five in the absorbent are not particularly limited, as long as the molar content of the fraction of carbon six and above is not more than 10%.
The effect of the mole content of the fractions with six or more carbon atoms on the temperature level of the tower bottom of the absorption tower is relatively large, and the effect of reducing the energy consumption can be achieved by reasonably controlling the mole content of the fractions with six or more carbon atoms. The source of the absorbent is not particularly limited in the present invention, and if the content of carbon six in the source of the absorbent is too high, carbon four can be appropriately supplemented to reduce the content of carbon six.
In a preferred embodiment, the absorbent enters from the top of the absorption column, the feed temperature of the absorbent being in the range of 1 to 30 ℃, preferably 5 to 20 ℃.
In a preferred embodiment, the theoretical plate number of the absorption column in the absorption column is 10 to 50, preferably 15 to 30; the operating pressure is 2-5MPa, preferably 2.8-4.3MPa.
In a preferred embodiment, the top temperature of the absorber is from 1 to 30 ℃, preferably from 5 to 20 ℃; the temperature of the tower kettle is 10-30 ℃, preferably 15-25 ℃.
In a preferred embodiment, at least 1 mid-section cooler, preferably 2 mid-section coolers are provided in the absorber column. Wherein the middle section cooler is arranged at the middle section of the absorption tower, and the temperature of the middle section cooler is 1-30 ℃, preferably 5-25 ℃.
The temperature of the absorbent can be increased after the absorbent is absorbed, and the arranged middle-stage intercooler can cool the absorbent again so as to improve the absorption effect.
In a preferred embodiment, the top products of the absorber are predominantly hydrogen, methane and nitrogen.
Wherein, the hydrogen, methane and nitrogen extracted from the top of the absorption tower can be sent to the boundary area to be used as fuel gas. Because the pressure of the hydrogen, methane and nitrogen extracted from the top of the tower is relatively high, and the boundary area is generally a fuel gas pipe network, the pressure is relatively low, and in order to avoid throttling, the hydrogen, methane and nitrogen extracted from the top of the absorption tower are preferably heated and then are discharged to the fuel gas pipe network after being subjected to work by an expansion machine.
In a preferred embodiment, an overhead heat exchanger is provided at the top of the absorber column for heating the top product of the absorber column.
In the step (2), the step of (C),
In a preferred embodiment, the bottoms product of the absorber column enters the demethanizer from the top of the demethanizer.
In a preferred embodiment, the bottoms product of the demethanizer is predominantly carbon two and above.
In the absorber, in order to enhance the absorption of the carbon two component by the absorbent, the column pressure of the absorber is relatively high. But higher column pressure also results in an increase in the absorption capacity of the absorbent for methane, resulting in a decrease in the separation efficiency of the absorber. In order to remove methane from the absorbent, reduce the content of methane in the feed of the desorption tower and improve the product purity of the polymerization grade ethylene, the invention carries out the demethanization treatment before the tower bottom material of the absorption tower is sent to the desorption.
In a preferred embodiment, the operating pressure of the demethanizer is from 0.1 to 3MPa, preferably from 0.5 to 2MPa, lower than the operating pressure of the absorber.
In a preferred embodiment, the demethanizer has a theoretical plate number of 10 to 50, preferably 15 to 30, and an operating pressure of 1 to 3.3MPa, preferably 1.2 to 2.7MPa;
in a preferred embodiment, the demethanizer has a top temperature of from 1 to 40 ℃, preferably from 5 to 20 ℃, and a bottom temperature of from 30 to 100 ℃, preferably from 40 to 80 ℃.
In the operating condition of the demethanizer, the operating pressure is lower and the tower bottom temperature is lower on the premise of ensuring the demethanizing effect, so that the energy consumption can be further reduced and the investment can be reduced.
In a preferred embodiment, the bottom of the demethanizer is provided with a bottom reboiler, and the bottom temperature of the demethanizer is controlled by the bottom reboiler of the demethanizer so that the molar methane content in the bottom product of the demethanizer is 0-0.1%, preferably 0-0.05%.
In a demethanizer, although the molar content of methane in the demethanizer bottoms product can be made less than 0.1% by controlling the demethanizer bottoms temperature, this results in a small portion of the carbon bi-components entering the demethanizer overhead. In the invention, the top product of the demethanizer is composed of methane, hydrogen and a small amount of carbon two components, and in order to improve the recovery rate of the carbon two components, the top product of the demethanizer is mixed with dry gas, compressed and cooled and then returned to the absorption tower.
In the present invention, in order to improve the product purity of the polymerization grade ethylene and the recovery rate of the carbon two components, the operations of step (1) and step (2) may be further performed according to the following methods: in a preferred embodiment, the dry gas is compressed and cooled, then introduced into a balance tank, the gas phase at the top of the balance tank is introduced into an absorption tower for absorption treatment, the gas phase contacts with an absorbent in the absorption tower to complete absorption operation, the tower top product of the absorption tower is sent out of a boundary region after the absorption operation is completed, the tower bottom product of the absorption tower is mixed with the compressed dry gas, and then cooled and returned to the balance tank; the liquid phase at the bottom of the balance tank is introduced into a demethanizer for demethanization, after the demethanization operation is finished, the top product of the demethanizer is mixed with dry gas and then is compressed and cooled to return to the balance tank, and the bottom product of the demethanizer is introduced into a desorption tower for desorption treatment, wherein the specific process flow is shown in figure 2.
In the present invention, the balance tank refers to a container that can complete gas-liquid phase separation. The gas phase at the tank top of the balance tank is mainly composed of a large amount of hydrogen, methane and carbon two or more components, and the liquid phase at the tank bottom of the balance tank is mainly composed of a small amount of hydrogen, a small amount of methane and a large amount of carbon two or more components; the tower top product of the absorption tower mainly comprises methane, hydrogen and nitrogen, the tower bottom product of the absorption tower mainly comprises carbon two or more components containing trace hydrogen and a small amount of methane, the tower top product of the demethanizer mainly comprises methane, hydrogen and a small amount of carbon two or more components, and the tower bottom product of the demethanizer mainly comprises carbon two or more components.
The top product of the demethanizer is compressed and cooled together with the dry gas and then returned to the balance tank, so that the recovery rate of the components with two or more carbon atoms is improved. The invention returns the tower bottom product of the absorption tower, the dry gas and the returned demethanizer top product to the balance tank after cooling, so as to realize the pre-absorption of the gas phase components entering the absorption tower by reducing the temperature of the product extracted from the bottom of the absorption tower and improve the recovery rate of the carbon two.
In a preferred embodiment, the dry gas is subjected to a cooling treatment after 2 compression treatments. Wherein the pressure of the dry gas after the 1 st compression is 1.0-3.2MPa, preferably 1.2-2.6MPa, and is mixed with the product extracted from the top of the demethanizer; the pressure of the dry gas after the 2 nd compression is 2.0-5.2MPa, preferably 2.0-4.5MPa, and the dry gas is mixed with the product extracted from the tower bottom of the absorption tower and enters a cooler, and the temperature of the cooled mixture is 1-30 ℃, preferably 5-20 ℃.
In a preferred embodiment, the operating conditions of the balancing tank include: the operating pressure is 2-5.2MPa, preferably 2-4.5MPa, and the operating temperature is 1-30deg.C, preferably 5-20deg.C.
In the step (3), the step of (c),
In the present invention, the purpose of the desorber is to initially separate the carbon bi-component from the bottoms product of the demethanizer. The tower top product extracted from the top of the desorption tower is coarse carbon two components and mainly comprises carbon two components, a small amount of carbon three or more components and trace methane, and the tower bottom product extracted from the tower bottom of the desorption tower is mainly carbon three or more components and mainly comprises carbon three, carbon four, carbon five, carbon six or more components.
In a preferred embodiment, the theoretical plate number of the desorber is 10 to 80, preferably 15 to 50; the operating pressure is 1-4.5MPa, preferably 1.6-3.2MPa.
In a preferred embodiment, the top temperature of the desorber is 5-100 ℃, preferably 10-70 ℃; the temperature of the tower kettle is 80-180 ℃, preferably 100-160 ℃.
In a preferred embodiment, the top of the desorption tower is provided with a condenser, and the bottom of the desorption tower is provided with a reboiler.
In a preferred embodiment, the crude carbon two components withdrawn from the top of the desorber column are introduced into the desorber column after a refining process, wherein the refining process comprises caustic washing and drying. In the present invention, the purpose of the refining treatment is to remove acid gases and water from the top product of the desorber.
In a preferred embodiment, the refining treatment further comprises one or more unit operations of amine scrubbing, deoxygenation and nitrogen oxides, desulfurization, dearsenification and demercuration, the specific operations and being selected according to actual requirements.
In a preferred embodiment, the bottoms product of the desorber is returned to the absorber. In the invention, the tower bottom product of the analysis tower is mainly absorbent, and the absorbent is returned to the absorption tower, so that the recycling of the absorbent can be realized, and the effect of reducing the cost is further achieved. In the production process, if the absorbent needs to be supplemented, the absorbent to be supplemented and a tower bottom product of the desorption tower can be mixed and then enter the absorption tower together.
In a preferred embodiment, a part of the bottoms product from the desorption column is returned to the absorption column and a part is withdrawn and sent outside the boundary zone. The extraction is to prevent accumulation of heavy components in the absorbent, and the amount of the extraction can be adjusted according to the actual situation, and the invention is not particularly limited.
In the step (4), the step of (c),
In the invention, the purpose of the heavy-removal tower is to purify the crude carbon bi-component, and further improve the purity of the carbon bi-component in the purified carbon bi-component. The tower top product extracted from the top of the heavy-removal tower is a purified carbon two component, and the purified carbon two component mainly comprises a carbon two component, a small amount of carbon three or more components and a trace amount of methane. Wherein the molar content of the three or more carbon components in the purified carbon two component is less than 5%, preferably less than 3%, more preferably less than 2%; the tower kettle product extracted from the heavy-removal tower kettle is mainly composed of three or more carbon components.
In a preferred embodiment, the theoretical plate number of the de-weight column is 5 to 50, preferably 10 to 35; the operating pressure is 1-3.8MPa, preferably 1.5-2.9MPa.
In a preferred embodiment, the top temperature of the de-weight column is from-30 ℃ to 30 ℃, preferably from-20 ℃ to 0 ℃; the temperature of the tower kettle is 60-180 ℃, preferably 80-140 ℃.
In a preferred embodiment, a condenser is arranged at the top of the heavy-removal tower, and a reboiler is arranged at the tower bottom of the heavy-removal tower.
The invention can remove carbon three or more components entrained in the ethylene rectifying tower feed by arranging the heavy-removal tower, so that the temperature of the ethylene rectifying tower kettle can be adjusted, and the temperature of the ethylene rectifying tower kettle is between-10 ℃ and 0 ℃.
In a preferred embodiment, the bottoms product from the de-heavies column bottoms is used to return to the absorber column.
In the step (5), the step of (c),
In the present invention, the purpose of the ethylene rectification column is to separate ethylene from ethane to obtain polymer grade ethylene. Wherein the overhead product withdrawn from the top of the ethylene rectification column is a non-condensable gas, which is mainly methane and ethylene, preferably, the non-condensable gas can be returned to the compressor in step (1); the line product taken from the top side of the ethylene rectification column is polymer grade ethylene, wherein the molar content of ethylene is greater than 99%, preferably greater than 99.9%, and more preferably greater than 99.95%; the bottoms product from the ethylene rectifying tower is an ethane-rich gas, wherein the ethane-rich gas comprises ethane and a small amount of carbon three and above components, and the molar content of the ethane is more than 90 percent, preferably more than 92 percent, and more preferably more than 94 percent.
In a preferred embodiment, the theoretical plate number of the ethylene rectification column is 80 to 200, preferably 100 to 150; the operating pressure is 1.2-2.8MPa, preferably 1.4-2.5MPa.
In a preferred embodiment, the top temperature of the ethylene rectification column is from-38 ℃ to-15 ℃, preferably from-33 ℃ to-20 ℃; the temperature of the tower bottom is-15 ℃ to 0 ℃, preferably-10 ℃ to 0 ℃.
In a preferred embodiment, the top of the ethylene rectifying tower is provided with a condenser and a side line extraction line, and the bottom of the ethylene rectifying tower is provided with a reboiler.
In order to fully utilize the hot materials in the invention and reduce energy consumption, in a preferred embodiment, the tower bottom product of the desorption tower is used as a heat source of an absorption tower top heat exchanger, a demethanizer tower bottom reboiler and an ethylene rectifying tower bottom reboiler.
The tower bottom product of the desorption tower can be divided into three parts and used as heat sources of an absorption tower top heat exchanger, a demethanizer tower bottom reboiler and an ethylene rectifying tower bottom reboiler respectively, or can be used as a heat source of an absorption tower top heat exchanger and/or a demethanizer tower bottom reboiler firstly and used as a heat source of an ethylene rectifying tower bottom reboiler.
In the invention, the tower bottom product of the desorption tower can be directly used as heat sources of an absorption tower top heat exchanger, a demethanizer tower bottom reboiler and an ethylene rectifying tower bottom reboiler, and the respective heat exchange requirements can be met by adjusting the flow of the tower bottom product of the desorption tower.
In a further preferred embodiment, in order to ensure stable operation of the ethylene rectification column, a cooler is preferably provided to regulate the temperature of the desorber bottoms product entering the ethylene rectification column bottoms reboiler to strictly control the feed temperature of the ethylene rectification column bottoms reboiler hot stream prior to use of the desorber bottoms product as the ethylene rectification column bottoms reboiler heat source.
According to the method for preparing the polymerization grade ethylene from the dry gas, provided by the invention, the tower bottom product of the desorption tower is used as a heating source of a tower bottom reboiler of the demethanizer, a tower top heat exchanger of the absorption tower and a tower bottom reboiler of the ethylene rectifying tower, so that the heat utilization rate is improved; by arranging the absorption tower and the demethanizer, the operating pressure of the demethanizer is reduced, so that a tower kettle reboiler of the demethanizer can only utilize a tower kettle product of the desorption tower as a heat source, and the consumption of steam is saved; by arranging the balance tank, the recovery rate of the carbon two components is further improved.
In a second aspect the present invention provides a dry gas polymerization grade ethylene plant, as shown in figure 1, comprising:
the absorption tower T1 is used for carrying out absorption treatment on the dry gas to obtain a tower kettle product containing two or more components;
The demethanizer T5 is used for carrying out demethanization treatment on the tower bottom product of the absorption tower so as to further obtain the tower bottom product containing two or more components;
A desorption tower T2 for carrying out desorption treatment on a tower bottom product of the demethanizer so as to obtain crude carbon two components from the top of the desorption tower;
A de-heavy tower T3 for de-heavy treatment of the crude carbon bi-component obtained from the top of the desorption tower to obtain a purified carbon bi-component from the top of the de-heavy tower;
and the ethylene rectifying tower T4 is used for separating the purified carbon two components obtained from the top of the heavy component removal tower to obtain the polymerization grade ethylene.
In a preferred embodiment, at least 1 mid-section cooler, preferably 2 mid-section coolers are provided in the absorber column.
In a preferred embodiment, the apparatus further comprises a compressor C1 for increasing the pressure of the dry gas and a cooler E1 for cooling the dry gas, the cooler E1.
In a preferred embodiment, a tower top heat exchanger is arranged at the tower top of the absorption tower, and tower bottom reboilers are respectively arranged at tower bottom of the demethanizer and the ethylene rectifying tower;
preferably, the tower bottom product of the desorption tower is used as heat sources of an absorption tower top heat exchanger, a demethanizer tower bottom reboiler and an ethylene rectifying tower bottom reboiler.
In a preferred embodiment, the apparatus further comprises a cooler E3, said cooler E3 being used to regulate the temperature of the stripper bottoms product entering the ethylene rectification column reboiler.
In a preferred embodiment, to prevent accumulation of heavy components in the absorbent, the stripper bottoms product is partially returned to the absorber and partially withdrawn. The invention is not particularly limited in the extraction stage, and extraction is completed before the ethylene rectifying tower enters the tower kettle reboiler.
In a preferred embodiment, as shown in fig. 2, the apparatus further comprises a balancing tank V1, wherein the compressor C1, the cooler E1 and the balancing tank V1 are connected in sequence, the top of the balancing tank is connected to the absorber tower T1, the bottom of the balancing tank is connected to the demethanizer tower T5, the bottom of the absorber tower is connected to the cooler E1, and the top of the demethanizer tower is connected to the compressor C1.
The dry gas is compressed by a compressor C1 and cooled by a cooler E1, and then is introduced into a balance tank V1 for gas-liquid phase separation treatment; introducing gas phase at the top of the balance tank into an absorption tower T1 for absorption treatment, and introducing liquid phase at the bottom of the balance tank into a demethanizer T5 for demethanization treatment; mixing a tower bottom product of the absorption tower with the dry gas compressed by the compressor C1, and cooling the mixture by the cooler E1 to return to the balance tank V1; the top product of the demethanizer is mixed with dry gas, compressed by a compressor C1 and cooled by a cooler E1, and then returned to the balance tank V1.
In a preferred embodiment, the apparatus further comprises an absorbent precooler E2 for cooling the material entering the absorption column. Wherein, the materials entering the absorption tower comprise absorbent, a tower bottom product of the desorption tower and a tower bottom product of the de-duplication tower.
The present invention will be described in detail by examples. Wherein the composition of the dry gas is shown in Table 1:
TABLE 1
Example 1
The process flow of the method for preparing the polymerization grade ethylene by adopting the dry gas is shown in figure 2, and a dry gas separation device is used, wherein the dry gas separation device comprises a compressor C1, a cooler E1, a balance tank V1, absorption towers T1 and K1-expansion machines, a demethanizer T5, a desorption tower T2 and U1-refining units, a weightlessness tower T3, an ethylene rectifying tower T4 and E2 absorbent precooler and a cooler E3. S1, dry gas, S2, tower top products of an absorption tower, S3, an absorbent, S4, tower bottom products of a resolving tower, S5, polymerization grade ethylene, S6, ethane-rich gas, S7 and tower top noncondensable gas of an ethylene rectifying tower.
The dry gas separation method comprises the following steps:
(1) The dry gas S1 is compressed and pressurized to 1.80MPa and then mixed with the gas phase component at the top of the demethanizer, compressed and pressurized to 4.0MPa and then mixed with the liquid phase of the absorption tower kettle, cooled to 14 ℃ and introduced into a balance tank.
(2) The operating pressure of the balance tank is 3.96MPa, and the temperature is 14 ℃. The balance tank top gas phase is introduced into the absorption tower. The absorbent was cooled to 5 ℃ and then fed into the absorber from the top of the absorber. Wherein the theoretical plate number of the absorption tower is 21, the operating pressure is 3.8MPa, the tower top temperature is 8.5 ℃, and the tower bottom temperature is 15 ℃. Two intercoolers are added in the absorption tower, wherein the temperature of the intercoolers is 13 ℃. S2 extracted from the top of the absorption tower is heated by using a desorption tower kettle product as a heat source, then steam condensate is used as a heat source to be heated to 100 ℃, the heat source is acted by an expander and then sent out of the boundary, the absorption tower kettle product is boosted to 4.2MPa by a pump, and then is mixed with dry gas at the outlet of a compressor, cooled to 14 ℃, and then enters a balance tank.
(2) The liquid phase product at the bottom of the balance tank V1 is further cooled to 10 ℃ and then enters from the top of the demethanizer, the theoretical plates of the demethanizer are 19, the pressure is 2.2MPa, the temperature of the top of the tower is 8.3 ℃, and the temperature of the bottom of the tower is 66.9 ℃. The demethanizer reboiler uses the stripper bottoms liquid stream as a heat source for heating. The top product of the demethanizer is returned to the space between the compressor sections and is mixed with dry gas of 1.8MPa to be further compressed and boosted. The bottom product of the demethanizer is mainly composed of two or more carbon components, and 0.04mol percent methane gas is entrained in the bottom product and sent to a desorption tower.
(3) The theoretical plates of the desorber are 40, the operating pressure is 2.6MPa, the temperature of the tower top is 55.5 ℃, and the temperature of the tower bottom is 135.9 ℃. In order to prevent heavy components in the absorbent from accumulating, a part of S4 is extracted from a product of a tower bottom of a desorption tower and sent out of the boundary, the rest part is sequentially used as a heating source of a reboiler of the tower bottom of the demethanizer and a heat exchanger at the top of the absorption tower, then the heating source is cooled to 51 ℃ by a cooler, then the heating source is used as a heating source of the reboiler of the tower bottom of the ethylene rectifying tower, and finally the heating source is returned to the absorption tower. The crude carbon two components extracted from the top of the desorption tower enter a refining unit, are sequentially subjected to alkaline washing and drying processes to remove acid gas and water, and are then sent into a heavy-removal tower.
(4) The theoretical plates of the weight-removing tower are 20, the operating pressure is 2.1MPa, the tower top temperature is-13.5 ℃, and the tower bottom temperature is 113.8 ℃. And returning the components with three or more carbon atoms extracted from the tower bottom of the heavy-removal tower to the absorption tower to be used as an absorbent. The mol content of the components with three or more carbon atoms in the purified carbon two component S5 extracted from the top of the heavy-removal tower is 1.7 percent, and the purified carbon two component S5 is sent to an ethylene rectifying tower.
(5) The theoretical plate number of the ethylene rectifying tower is 102, the operating pressure is 1.85MPa, the tower top temperature is-30.3 ℃, the tower bottom temperature is-4.1 ℃, the tower top noncondensable gas S7 returns to the space between the compressor sections, the tower bottom side line is used for extracting liquid phase polymerization grade ethylene S5, and the tower bottom is used for extracting ethane-rich gas S6.
Wherein the composition in streams S1-7 and the energy consumption in the separation process are shown in Table 2:
TABLE 2
Comparative example 1
Ethylene is separated by adopting a refinery dry gas separation method in CN109912379A, and the process flow is shown in figure 3: wherein, the device comprises a c 1-compressor, a first e 1-cooler, a second e 2-cooler, a third e 3-cooler, a t 1-absorption tower, a t 2-desorption tower, a t 3-demethanizer, a t 4-ethylene rectifying tower, a t 5-reabsorption tower, a t 6-gasoline stabilizer, a u 1-refining unit (comprising alkaline washing and drying), a k 1-expansion machine, s 1-dry gas, a top gas phase of a s 2-reabsorption tower, s 3-supplementary fresh absorbent, s 4-part tower kettle material discharge, s 5-polymerization grade ethylene product, s 6-ethane-rich product and s 7-noncondensable gas.
The dry gas separation method comprises the following steps:
(1) The dry gas is compressed and pressurized to 3.80MPa.
(2) The gas phase obtained by the compression treatment was cooled to 15 ℃.
(3) The absorbent contains 0.04% of propane, 0.4% of propylene, 68.0% of n-butane and 7.2% or more of carbon six. The absorbent is cooled to 13 ℃ and then enters from the top of the absorption tower to absorb the fractions with two or more carbon atoms in the dry gas.
(4) The theoretical plates of the absorption tower are 33, the pressure is 3.8MPag, the tower top temperature is 15.8 ℃, and the tower bottom temperature is 98.8 ℃. The top gas of the absorber column is sent to a reabsorption column. The absorption section of the absorption tower is added with 2 intercoolers to improve the absorption effect, and the temperature of the intercoolers is 13 ℃.2 middle boilers are added in the stripping section of the absorption tower, and a desorption tower kettle material flow is used as a heat source of the middle boilers. The methane content in the tower bottom product is 0.2 mol percent, and the product is sent to a desorption tower.
(5) The theoretical plates of the desorber are 40, the operating pressure is 2.6MPa, the tower top temperature is 36.0 ℃, and the tower bottom temperature is 139.3 ℃. And returning the tower bottom product of the desorption tower to the absorption tower to be used as an absorbent. In order to fully utilize the system waste heat, the product of the desorption tower kettle is sequentially used as a heat source for heating the gas phase of the boiling device in the 2 stripping sections of the absorption tower and the top of the reabsorption tower. Then cooled to 40 ℃ by an e2 absorbent water cooler, and finally cooled to 13 ℃ by an e3 absorbent cooler.
(6) To maintain a stable circulating absorbed dose, a fresh absorbent of n-butane needs to be replenished. In order to prevent the accumulation of heavy components in the absorbent, a strand of the product is extracted from the desorber kettle and sent out of the boundary.
(7) The gas at the top of the absorption tower enters a reabsorption tower, the theoretical plates of the reabsorption tower are 15, the operation pressure is 3.6MPa, the temperature at the top of the tower is 17.4 ℃, and the temperature at the bottom of the tower is 31.5 ℃. And heating the steam condensate to 100 ℃ by using the steam condensate as a heat source, and then performing work by an expander and sending out the heat source. And the tower bottom product enters a gasoline stabilizer.
(8) The theoretical plates of the gasoline stabilizer are 33, the operating pressure is 0.70MPa, the tower top temperature is 63 ℃, and the tower bottom temperature is 158.5 ℃. And one part of liquid phase at the top of the tower returns to the absorption tower to be used as a circulating absorbent, and the other part of liquid phase is used as reflux.
(9) The gas at the top of the desorption tower enters a refining unit and is sequentially subjected to alkaline washing and drying processes to remove the acid gas and water.
(10) The number of theoretical plates of the demethanizer is 25, the operating pressure is 2.1MPa, the tower top temperature is-20.7 ℃, and the tower bottom temperature is-12.2 ℃. And the liquid phase in the tower bottom enters an ethylene rectifying tower.
(11) The theoretical plate number of the ethylene rectifying tower is 102, the operating pressure is 1.85MPa, the tower top temperature is-30.3 ℃, and the tower bottom temperature is 14.3 ℃. The non-condensable gas at the top of the tower returns to the space between the compressor sections, the liquid phase polymerization grade ethylene product is extracted from the side line of the tower kettle, and the ethane-rich product is extracted from the tower kettle.
Wherein the composition of streams s1-8 and the energy consumption during separation are shown in Table 3:
TABLE 3 Table 3
Compared with example 1, the electricity consumption of comparative example 1 was 9962 kwh/hr, increased by 21.6%, and the steam consumption was 33.5 tons/hr, increased by 74.7%. On the one hand, in the invention, the operation pressure of the demethanizer is lower than that of the absorber by arranging the absorber and the demethanizer, so that the tower bottom material flow of the desorber can be used as the heat source of the reboiler of the demethanizer, and the consumption of steam is saved. On the other hand, the tower bottom product of the desorption tower is used as a heating source of the heat exchanger at the top of the absorption tower and the reboiler at the tower bottom of the ethylene rectifying tower, so that the heat utilization rate is further improved, and the energy consumption in the production process of the polymerization grade B is reduced.
The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, a number of simple variants of the technical solution of the invention are possible, including combinations of the individual technical features in any other suitable way, which simple variants and combinations should likewise be regarded as being disclosed by the invention, all falling within the scope of protection of the invention.
Claims (23)
1. A process for dry gas polymerization grade ethylene, comprising the steps of:
(1) Introducing dry gas into an absorption tower for absorption treatment to obtain a tower kettle product containing two or more components;
(2) Introducing a tower bottom product of the absorption tower into a demethanizer for demethanization so as to further obtain a tower bottom product containing two or more components, wherein the operating pressure of the demethanizer is lower than that of the absorption tower; the top temperature of the demethanizer is 1-40 ℃, the operating pressure is 1-3.3MPa, and the bottom temperature is 30-100 ℃; the operating pressure of the demethanizer is 0.1-3MPa lower than the operating pressure of the absorber;
(3) Introducing a tower bottom product of the demethanizer into a desorption tower for desorption treatment so as to obtain crude carbon two components from the top of the desorption tower;
(4) Introducing the crude carbon bi-component obtained from the top of the desorption tower into a de-heavy tower for de-heavy treatment so as to obtain purified carbon bi-component from the top of the de-heavy tower;
(5) Introducing the purified carbon two components obtained from the top of the heavy-removal tower into an ethylene rectifying tower for separation treatment to obtain polymer grade ethylene;
Wherein the method further comprises: after compressing and cooling, introducing dry gas into a balance tank for gas-liquid phase separation treatment; introducing a gas phase at the top of the balance tank into an absorption tower for absorption treatment, and introducing a liquid phase at the bottom of the balance tank into a demethanizer for demethanization treatment;
Wherein, the tower bottom product of the absorption tower is mixed with the compressed dry gas and then is cooled and returned to the balance tank; the top product of the demethanizer is mixed with dry gas and then is compressed and cooled to return to the balance tank;
Wherein, a tower top heat exchanger is arranged at the tower top of the absorption tower, and tower kettle reboilers are respectively arranged at the tower bottoms of the demethanizer and the ethylene rectifying tower;
wherein the method further comprises: returning the tower bottom product of the desorption tower to the absorption tower;
And using the product of the tower bottom of the desorption tower as heat sources of a heat exchanger at the top of the absorption tower, a reboiler at the tower bottom of the demethanizer and a reboiler at the tower bottom of the ethylene rectifying tower.
2. The process of claim 1, wherein the operating pressure of the demethanizer is from 0.5 to 2 MPa lower than the operating pressure of the absorber.
3. The process according to claim 1 or 2, wherein in step (1), the theoretical plate number of the absorption column is 10 to 50 and the operating pressure is 2 to 5MPa.
4. A process according to claim 3, wherein in step (1), the theoretical plate number of the absorption column is 15 to 30, and the operating pressure is 2.8 to 4.3MPa.
5. The process according to claim 1 or 2, wherein the absorber tower top temperature is 1-30 ℃ and the tower bottom temperature is 10-30 ℃.
6. The process according to claim 5, wherein the temperature at the top of the absorption column is 5-20 ℃ and the temperature at the bottom of the column is 15-25 ℃.
7. The process of claim 1, wherein in step (2), the demethanizer has a theoretical plate number of 10 to 50.
8. The process of claim 7 wherein in step (2) the demethanizer has a theoretical plate number of 15 to 30 and an operating pressure of 1.2 to 2.7MPa.
9. The process of claim 1 wherein the demethanizer overhead temperature is from 5 to 20 ℃ and the bottoms temperature is from 40 to 80 ℃.
10. The method of claim 1, wherein the operating conditions of the balancing tank include: the operating pressure is 2-5.2MPa, and the operating temperature is 1-30 ℃.
11. The method of claim 10, wherein the operating conditions of the balancing tank include: the operating pressure is 2-4.5MPa, and the operating temperature is 5-20 ℃.
12. The process according to claim 1, wherein in step (3), the theoretical plate number of the desorber is 10 to 80 and the operating pressure is 1 to 4.5MPa.
13. The process according to claim 12, wherein in step (3), the theoretical plate number of the desorber is 15 to 50 and the operating pressure is 1.6 to 3.2MPa.
14. The process according to claim 1, wherein the top temperature of the desorber is 5-100 ℃ and the bottom temperature is 80-180 ℃.
15. The process of claim 14, wherein the desorber has a top temperature of 10-70 ℃ and a bottom temperature of 100-160 ℃.
16. The process according to claim 1, wherein in step (4), the theoretical plate number of the weight-loss column is 5 to 50 and the operating pressure is 1 to 3.8MPa.
17. The process according to claim 16, wherein in step (4), the theoretical plate number of the weight-loss column is 10 to 35 and the operating pressure is 1.5 to 2.9MPa.
18. The method of claim 1, wherein the de-weight column has a top temperature of-30 ℃ to 30 ℃ and a bottom temperature of 60-180 ℃.
19. The method of claim 18, wherein the de-weight column has a top temperature of-20 ℃ to 0 ℃ and a bottom temperature of 80-140 ℃.
20. The process according to claim 1, wherein in step (5), the theoretical plate number of the ethylene rectification column is 80 to 200 pieces and the operating pressure is 1.2 to 2.8MPa.
21. The process according to claim 20, wherein in step (5), the theoretical plate number of the ethylene rectification column is 100 to 150 pieces and the operating pressure is 1.4 to 2.5MPa.
22. The process of claim 1, wherein the ethylene rectification column has a top temperature of-38 ℃ to-15 ℃ and a bottom temperature of-15 ℃ to 0 ℃.
23. The process of claim 22, wherein the ethylene rectification column has a top temperature of-33 ℃ to-20 ℃ and a bottom temperature of-10 ℃ to 0 ℃.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011216776.9A CN114436745B (en) | 2020-11-04 | 2020-11-04 | Method and device for preparing polymerization grade ethylene by dry gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011216776.9A CN114436745B (en) | 2020-11-04 | 2020-11-04 | Method and device for preparing polymerization grade ethylene by dry gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114436745A CN114436745A (en) | 2022-05-06 |
| CN114436745B true CN114436745B (en) | 2024-07-02 |
Family
ID=81361623
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011216776.9A Active CN114436745B (en) | 2020-11-04 | 2020-11-04 | Method and device for preparing polymerization grade ethylene by dry gas |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114436745B (en) |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103030494A (en) * | 2012-12-21 | 2013-04-10 | 天津大学 | Absorption and hydration coupling device and method for separating ethylene and ethane in catalytic cracking dry gas or ethylene pyrolysis gas |
| CN109912380A (en) * | 2017-12-12 | 2019-06-21 | 中国石油化工股份有限公司 | A kind of cracking gas separation method and device |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104892340A (en) * | 2015-06-10 | 2015-09-09 | 天津大学 | Three-tower device and method for recycling ethylene and ethane from dry gas through oil absorption |
| CN107602333B (en) * | 2016-07-12 | 2021-05-11 | 中国石油化工股份有限公司 | Separation method of methanol-to-olefin reaction gas |
| CN109678635B (en) * | 2017-10-19 | 2022-03-15 | 中国石油化工股份有限公司 | Saturated hydrocarbon cracking gas separation system and utilization method of ethane/propane-rich saturated hydrocarbon |
| CN109912379B (en) * | 2017-12-12 | 2022-07-12 | 中国石油化工股份有限公司 | Refinery dry gas separation method and device |
| CN111320522B (en) * | 2018-12-14 | 2022-12-13 | 中国石油化工股份有限公司 | Method and device for separating ethylene from refinery dry gas |
-
2020
- 2020-11-04 CN CN202011216776.9A patent/CN114436745B/en active Active
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103030494A (en) * | 2012-12-21 | 2013-04-10 | 天津大学 | Absorption and hydration coupling device and method for separating ethylene and ethane in catalytic cracking dry gas or ethylene pyrolysis gas |
| CN109912380A (en) * | 2017-12-12 | 2019-06-21 | 中国石油化工股份有限公司 | A kind of cracking gas separation method and device |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114436745A (en) | 2022-05-06 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109912379B (en) | Refinery dry gas separation method and device | |
| CN109912380B (en) | Pyrolysis gas separation method and device | |
| CN104557387B (en) | Refinery mixed dry gas recovery system and recovery method | |
| CN104557384A (en) | Refinery mixed dry gas recovery system and recovery method | |
| CN212833550U (en) | Propane dehydrogenation product separation device | |
| CN102502634B (en) | Technological method for preparing food-grade CO2 based on high-concentration carbon dioxide exhaust gas | |
| CN107954815B (en) | Separation method of propane dehydrogenation reaction gas | |
| CN103030494B (en) | Absorption and hydration coupling device and method for separating ethylene and ethane in catalytic cracking dry gas or ethylene pyrolysis gas | |
| CN112410070B (en) | Energy-saving process and device for recovering carbon dioxide from refinery dry gas | |
| CN107602325B (en) | Separation method of methanol-to-olefin reaction gas | |
| CN110950733B (en) | Separation device and method for preparing olefin gas from methanol | |
| CN114436745B (en) | Method and device for preparing polymerization grade ethylene by dry gas | |
| CN111320523B (en) | Method and device for separating ethylene from refinery dry gas | |
| CN111004079B (en) | Separation method and device for reaction gas for preparing ethylene by oxidative coupling of methane | |
| CN104560194B (en) | Refinery saturated dry gas recovery system and recovery method | |
| CN107602331B (en) | Separation method of methanol-to-olefin reaction gas | |
| CN107602333B (en) | Separation method of methanol-to-olefin reaction gas | |
| CN112194550B (en) | Method and device for separating carbon-rich two-carbon three-dry gas | |
| CN112410071B (en) | Method and system for separating refinery unsaturated dry gas | |
| US20230332061A1 (en) | Energy-saving process and device for recovering c2 from refinery dry gas | |
| CN111004082A (en) | System and method for removing carbon dioxide from C2 fraction | |
| CN114436747B (en) | Method and system for preparing polymerization grade ethylene by using dry gas | |
| CN106631664A (en) | Separation method for methanol-to-olefin reaction gas | |
| CN112410067B (en) | Method for separating saturated dry gas of refinery plant | |
| CN210711336U (en) | Front deethanization separation device of ethane cracking device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant |