CN213977484U - Device system for separating ethylene and ethane in catalytic dry gas - Google Patents
Device system for separating ethylene and ethane in catalytic dry gas Download PDFInfo
- Publication number
- CN213977484U CN213977484U CN202022855810.9U CN202022855810U CN213977484U CN 213977484 U CN213977484 U CN 213977484U CN 202022855810 U CN202022855810 U CN 202022855810U CN 213977484 U CN213977484 U CN 213977484U
- Authority
- CN
- China
- Prior art keywords
- tower
- ethylene
- gas
- ethane
- swing adsorption
- 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
Images
Landscapes
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Separation Of Gases By Adsorption (AREA)
Abstract
The patent of the utility model belongs to the technical field of retrieve the catalysis dry gas, especially, relate to a device system of ethylene and ethane in separation catalysis dry gas, its characterized in that: the device is provided with a gas-liquid separation mechanism, a pressure swing adsorption mechanism, a compression mechanism, a purification mechanism and a cryogenic rectification mechanism, wherein the gas-liquid separation mechanism is connected with the pressure swing adsorption mechanism, the pressure swing adsorption mechanism is connected with the compression mechanism, the compression mechanism is connected with the purification mechanism, and the purification mechanism is connected with the cryogenic rectification mechanism; all the mechanisms are connected into a whole through pipelines. The utility model discloses simple structure, easy operation, separation ethylene and ethane purity are high, and the production energy consumption is low, and the benefit is high.
Description
Technical Field
The utility model belongs to the technical field of retrieve the separation of catalytic dry gas and retrieve, especially, relate to a device system of ethylene and ethane in separation catalytic dry gas.
Background
Generally, 13 percent of ethylene and 13 percent of ethane exist in the catalytic dry gas, the content of the ethylene and the ethane in the catalytic dry gas is changed in a certain range along with the process adjustment of a catalytic device, and the ethylene and the ethane are both production raw materials of the ethylene and have high recovery value. At present, the industrial technology for recovering ethylene and ethane in catalytic dry gas comprises processes such as cryogenic separation, oil absorption, membrane separation, pressure swing adsorption and the like, the cryogenic separation technology utilizes boiling point difference to separate the ethylene and the ethane, the purity of the obtained ethylene product and the ethane product is high, but the cryogenic separation technology is suitable for large-scale catalytic dry gas recovery, otherwise, the energy consumption is high; membrane separation utilizes the difference of the diffusion performance of each component of the catalytic dry gas in the membrane for separation, but the membrane has poor separation of hydrocarbons from methane and is greatly influenced by sulfur and other impurities; the pressure swing adsorption separation technology utilizes the difference of adsorption performance of an adsorbent on dry gas components to separate, the dry gas components are adsorbed at normal temperature and under the pressure of the dry gas, the dry gas components are evacuated and desorbed at the normal temperature, the energy consumption of the recovery process is mainly the power consumption of a vacuum pump and the consumption of cooling water of the vacuum pump, so the energy consumption is particularly low, and the adsorbent can resist impurities such as sulfur, arsenic and the like after being modified, but the mixed gas of ethylene and ethane is obtained by a pressure swing adsorption method.
For small-scale catalytic dry gas. The method for separating ethylene and ethane by coupling the advantages of cryogenic separation and pressure swing adsorption is an economical and feasible method for obtaining high-purity ethylene and ethane.
The catalytic dry gas contains impurities such as carbon dioxide, sulfide, particularly hydrogen sulfide, nitrogen oxide, oxygen, water, arsenic, mercury and the like, the carbon dioxide and the water block pipelines in a low-temperature device, the nitrogen oxide and dinitrogen trioxide and dinitrogen tetroxide generated by the oxygen react with diolefin at the temperature of minus 80 ℃ to generate gummy nitride, and the gummy nitride is rapidly decomposed, combusted and exploded under the influence of temperature, so the low-temperature unit can be fed after the nitrogen oxide is removed. Hydrogen sulfide in the catalytic dry gas corrodes pipeline equipment and other sulfides which influence the activity of the catalyst in the subsequent use of ethylene, and the total sulfur S of a high-purity ethylene product is required to be less than or equal to 1.0mg/m3. Arsenic in the catalytic dry gas permanently deactivates the hydrogenation catalyst. Mercury in the catalytic dry gas accumulates in low-temperature equipment to damage the equipment, and the activity of the hydrogenation catalyst is also reduced. Therefore, the impurities in the catalytic dry gas need to be purified and removed.
Chinese patent ZL00113109.5 'method for separating and recovering ethylene, ethane, propylene and hydrogen from mixed gas containing hydrocarbons' discloses a method for separating and obtaining ethylene, ethane, propylene and hydrogen from mixed gas containing hydrocarbons by combining absorption, temperature swing adsorption, pressure swing adsorption and cryogenic separation in sequence. An absorption unit is arranged before pressure swing adsorption to remove acid gas in the mixed gas so as to lead CO to be2The purification precision reaches 1.0ml/m3And to remove H2Sulfides other than S, in particular mercaptan sulfides, are not able to reach 1.0ml/m3The purification precision of (2); before pressure swing adsorption, a temperature swing adsorption unit is arranged to remove C5 heavy hydrocarbon in the mixed gas to 1.0ml/m3The recovery energy consumption is increased, and the purification of impurities such as arsenic, mercury, nitrogen oxides and the like in the catalytic dry gas is not mentioned.
Chinese patent ZL201410220969.X discloses a method and a device for clearly separating and refining catalytic cracking dry gas with high yield and high purity, which discloses that the catalytic cracking dry gas is sequentially pressurized and purified, separated by a first pressure swing adsorption tower and a second pressure swing adsorption tower, repressurized and then subjected to membrane separation, and non-permeable steam after the membrane separation enters a cryogenic separation system to obtain methane, ethylene, ethane and propylene. According to the catalytic cracking dry gas purification method, the pressure of the catalytic cracking dry gas is firstly increased to 0.7-1.2 MPa by a compressor, and then the catalytic cracking dry gas is purified by methods such as mercaptan and carbonyl sulfide removal in a hydrogenation reduction reactor, so that subsequent poisoning conditions such as a pressure swing adsorbent and a membrane module are avoided; the ethylene-rich dry gas of the first pressure swing adsorption unit and part of desorption gas of the second pressure swing adsorption unit are mixed and pressurized to 1.0-3.5 MPa, and then enter a membrane separation unit, the process needs to be pressurized by a compressor for 2 times, and the operation pressure is higher; in the patent, the adsorbent and the membrane of the pressure swing adsorption unit are affected by sulfide and other impurities to be poisoned and disabled, so that the catalytic cracking dry gas is purified before pressure swing adsorption, the scale and the cost of the purification unit are increased, and the purification unit comprises: the conventional hydrodeoxygenation reactor deoxygenation, the conventional hydrodeoxygenation reactor desulfurization alcohol and carbonyl sulfide generally need to increase the temperature of catalytic cracking dry gas for hydrogenation reaction, and the thioether treatment mode possibly existing in the catalytic cracking dry gas is not mentioned; removing arsenic and mercury in the catalytic dry gas by using a molecular sieve; oxygen and nitrogen oxides are respectively removed by arranging a hydrogenation reactor, and people in the field know that the purification method and the process flow of the patent cause the technology of the patent to have high energy consumption for operation and harsh operating conditions for use.
Chinese patent ZL201210042148.2 "method for producing ethylene-propylene copolymer by recycling ethylene and hydrogen in refinery catalytic dry gas" discloses a method for producing ethylene-propylene copolymer by recycling ethylene and hydrogen in refinery catalytic dry gas through the processes of desulfurization, decarburization, deoxidation, dearsenization, heavy hydrocarbon removal, drying and pressure swing adsorption of special adsorbents for olefins such as zeolite molecular sieves, complex copper systems, silver systems and the like. Because of the special adsorbent process of pressure swing adsorption in the patent, the processes of desulfurization, decarburization and drying pre-purification are required before pressure swing adsorption, so as to avoid poisoning of the adsorbent in the subsequent process. The pressure swing adsorption temperature is 50-200 ℃, preferably 80-150 ℃, the obtained ethylene content is more than 85%, and the process energy consumption is high.
From the above analysis, most of the existing conventional technologies have the technical problems of complex process flow and high energy consumption, and the process is simplified in order to reduce the energy consumption for separating ethylene and ethane from catalytic dry gas, so that a novel device system with low energy consumption and simple process is urgently needed.
SUMMERY OF THE UTILITY MODEL
In order to solve the technical problem, the utility model provides a device system of ethylene and ethane in separation catalysis dry gas, simple structure, easy operation, separation ethylene and ethane purity are high, and the production energy consumption is low, and the benefit is high.
Solve technical problem above the utility model provides a device system of ethylene and ethane in separation catalysis dry gas, its characterized in that: the device is provided with a gas-liquid separation mechanism, a pressure swing adsorption mechanism, a compression mechanism, a purification mechanism and a cryogenic rectification mechanism, wherein the gas-liquid separation mechanism is connected with the pressure swing adsorption mechanism, the pressure swing adsorption mechanism is connected with the compression mechanism, the compression mechanism is connected with the purification mechanism, and the purification mechanism is connected with the cryogenic rectification mechanism; all the mechanisms are connected into a whole through pipelines.
The pressure swing adsorption mechanism is formed by connecting 5 or more than 5 adsorbers in parallel into a whole, and each adsorber is internally provided with an adsorbent. The ethylene-rich concentrated gas obtained from the lower part of the adsorber is sent to a compression unit, and the hydrogen-rich methane gas obtained from the top can be used as fuel or hydrogen extraction raw material.
The adsorption temperature in the pressure swing adsorption mechanism is 25-40 ℃, and the operation steps comprise adsorption, replacement, pressure equalization reduction, reverse discharge, evacuation, pressure boosting and the like.
The compression mechanism is an ethylene-rich concentrated gas compressor, and the ethylene-rich concentrated gas obtained by pressure swing adsorption is pressurized to 0.8-2.0 MPag.
The purification mechanism is provided with an amine absorption tower, a fine desulfurization tower, an arsenic removal mercury tower, a denitrogenation oxide tower, an alkali absorption tower and a drying tower, wherein the amine absorption tower is connected with the fine desulfurization tower; the towers are connected into a whole through pipelines.
The compressor is connected with the lower part of the amine absorption tower, and the top end part of the amine absorption tower is connected with the fine desulfurization tower.
The low-temperature rectification mechanism is provided with a refrigeration system, a decarburization three-tower, a demethanizer and a separation ethylene and ethane tower, wherein the refrigeration system is connected with the decarburization three-tower, the top end part of the decarburization three-tower is connected with the demethanizer, the demethanizer is connected with the separation ethylene and ethane tower, and the drying tower is connected with the refrigeration system. The methane-rich gas is output from the demethanizer, the mixed hydrocarbon is output from the lower part of the decarbonization three-tower, the high-purity ethylene is output from the top end part of the ethylene and ethane separation tower, and the ethane is output from the lower part of the ethylene and ethane separation tower.
The refrigeration system is a refrigerator.
After gas-liquid separation, the catalytic dry gas is subjected to pressure swing adsorption unit comprising adsorption, replacement, pressure equalization reduction, reverse release, evacuation and pressure boosting steps to remove most of hydrogen, oxygen, nitrogen and methane in the catalytic dry gas, and hydrocarbon components above carbon two are concentrated to obtain ethylene-rich gas; the compression unit pressurizes the ethylene-rich concentrated gas to 0.8-2.0 MPag; then the wastewater enters a purification unit to remove carbon dioxide, sulfide, arsenic and mercury, nitrogen oxide and water; the purified gas enters a cryogenic rectification unit to separate ethylene and ethane, and ethylene with the purity of more than 99.9 percent, ethane with the purity of more than 98 percent and mixed hydrocarbon are obtained. And after gas-liquid separation, the liquid enters other devices for treatment.
The utility model discloses with pressure swing adsorption separation mechanism, purification mechanism and cryogenic rectification mechanism coupling, updated the adsorbent, adsorption temperature is 25 ~ 40 ℃, the adsorbent has better adsorption and desorption performance to heavy hydrocarbon, guarantee the long-term use of adsorbent, thereby cancelled the temperature swing adsorption unit who gets rid of heavy hydrocarbons such as C5 among the catalysis dry gas, the catalysis dry gas utilizes direct entering pressure swing adsorption unit absorption behind the conventional vapour and liquid separator separation liquid material of catalysis dry gas, process flow has been simplified, the regeneration energy consumption of temperature swing adsorption unit has been cancelled; the compression of the catalytic dry gas is reduced, the pressure of the catalytic dry gas is utilized for direct adsorption and separation, and the compression energy consumption of the catalytic dry gas is cancelled; a fine desulfurization process is added in the purification unit, and the process adopts a desulfurizing agent to remove sulfides such as mercaptan, thioether and the like at normal temperature, so that the total sulfur in the ethylene concentrated gas is less than or equal to 1.0mg/m3, and the energy consumption of desulfurization is avoided; in the arsenic and mercury removing process in the purification unit, the arsenic and mercury removing agent is used for removing at normal temperature, and energy consumption is avoided. All purifying agents except the drying agent do not need to be regenerated, and are directly replaced after the service life period, so that the operation is simple; in the whole process, only the ethylene-rich concentrated gas subjected to pressure swing adsorption needs to be pressurized, the pressure is only 0.8-2.0 MPag, and the compression energy consumption is low.
The utility model discloses in adopt pressure swing adsorption technique, purification technique and cryogenic rectification technical coupling separation catalysis ethylene and ethane in the dry gas, obtain the ethylene that purity is greater than 99.9%, the ethane that purity is greater than 98%. Wherein the impurity CO of the ethylene is less than or equal to 1.0ml/m3、CO2
≤5.0ml/m3、H2≤1.0ml/m3、O2≤1.0ml/m3、S≤1.0mg/m3、H2O≤5.0ml/m3、CH4+C2H6≤500ml/m3。
Drawings
The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments:
FIG. 1, FIG. 2 and FIG. 3 are schematic structural views of the present invention
FIG. 4 is a schematic view of the pressure swing adsorption structure of the present invention
1. Gas-liquid separator, pressure swing adsorption mechanism 2, compressor 3, amine absorption tower 4, fine desulfurization tower 5, dearsenifying mercury tower 6, denitrogenation oxide tower 7, alkali absorption tower 8, drying tower 9, decarbonization tower 10, demethanization tower 11, ethylene and ethane separating tower 12, purifying mechanism 13, pipeline 14, absorber 15, program control valve 16, insulating layer 17, pressure gauge 18, regulating valve 19, hydrogen-rich methane gas output pipe 20, semi-product gas output pipe 21, vacuum pump 22, vacuum pump 23, raw material input pipe 24, refrigerating system 24
Detailed Description
The present invention will be further explained with reference to the following embodiments, in which the structure of the refrigerating system, the gas-liquid separator, the absorber, the compressor and other devices is conventional:
example 1
A device system for separating ethylene and ethane in catalytic dry gas is provided with a gas-liquid separation mechanism, a pressure swing adsorption mechanism, a compression mechanism, a purification mechanism and a cryogenic rectification mechanism, wherein the gas-liquid separation mechanism is connected with the pressure swing adsorption mechanism, the pressure swing adsorption mechanism is connected with the compression mechanism, the compression mechanism is connected with the purification mechanism, and the purification mechanism is connected with the cryogenic rectification mechanism; all the mechanisms are connected into a whole through pipelines.
Wherein the gas-liquid separation mechanism is a gas-liquid separator; the pressure swing adsorption mechanism is formed by connecting 5 or more than 5 adsorbers in parallel into a whole, each adsorber is internally provided with an adsorbent, the bottom end part of the adsorber is connected with a vacuum pump through a program control valve, and the lower part of the adsorber obtains ethylene-rich concentrated gas to be sent to a compression unit; the top end of the pressure swing adsorption mechanism is connected with a fuel gas pipe network or a hydrogen extraction device, and the hydrogen-rich methane gas obtained from the top can be used as fuel or hydrogen extraction raw material. The gases obtained in the cryogenic rectification plant are separately conveyed out of the plant.
The compression mechanism is an ethylene-rich concentrated gas compressor, and the ethylene-rich concentrated gas obtained by pressure swing adsorption is pressurized to 0.8-2.0 MPag.
The purification mechanism is provided with an amine absorption tower, a fine desulfurization tower, an arsenic removal tower, a nitrogen and oxide removal tower, an alkali absorption tower and a drying tower, wherein the amine absorption tower is connected with the fine desulfurization tower; the towers are connected into a whole through pipelines.
The compressor is connected with the lower part of the amine absorption tower, and the top end part of the amine absorption tower is connected with the fine desulfurization tower.
The low-temperature rectification mechanism is provided with a refrigeration system, a decarburization three-tower, a demethanizer and a separation ethylene and ethane tower, wherein the refrigeration system is connected with the decarburization three-tower, the top end part of the decarburization three-tower is connected with the demethanizer, the demethanizer is connected with the separation ethylene and ethane tower, the drying tower is connected with the refrigeration system, and the refrigeration system is connected with the decarburization three-tower. The methane-rich gas is output from the demethanizer, the mixed hydrocarbon is output from the lower part of the decarbonization tower, the high-purity ethylene is output from the top end part of the ethylene and ethane separation tower, and the ethane is output from the lower part of the ethylene and ethane separation tower.
Specifically, the pressure swing adsorption mechanism is provided with a pressure swing adsorption device, a hydrogen-rich methane gas output pipe and a semi-product output pipe, wherein the pressure swing adsorption device is provided with 5 or more adsorbers, program control valves, a pressure gauge and a vacuum pump, the adsorbers are connected in parallel, the upper end and the lower end of each adsorber are respectively provided with the program control valves, and the hydrogen-rich methane gas output pipe is connected with the top ends of the adsorbers through the program control valves; one end of the vacuum pump is connected with the bottom end of the absorber through a program control valve, and the other end of the vacuum pump is connected with an output pipe of the ethylene-rich concentrated semi-product gas; the pressure gauge is arranged between the top end of the adsorber and the program control valve. The inlet of the compressor is connected with the outlet of the vacuum pump through a pipeline and a program control valve, the hydrogen-rich methane gas passes through the program control valve and a pipeline discharge device which are connected with the upper outlet of the adsorber, the lower outlet of the adsorber is connected with the vacuum pump through a pipeline and a program control valve, and the concentrated gas pumped by the vacuum pump is compressed by the semi-product compressor and then output to the purification mechanism; all units are connected through pipelines; wherein the working state and the gas trend of the adsorber of the pressure swing mechanism are controlled by a program control valve. The outer surface of the absorber is provided with a heat-insulating layer. And a regulating valve is also arranged between the hydrogen-rich methane gas output pipe and the program control valve.
The pressure swing adsorption device is a continuous operation system consisting of 5 or more than 5 adsorbers, and the adsorbers are connected in parallel. The adsorbers are filled with adsorbent, and each adsorber sequentially undergoes the steps of adsorption, replacement, pressure equalization reduction, reverse discharge, evacuation, pressure boosting and the like.
The method comprises the following specific steps:
(1) adsorption
The catalytic dry gas after gas-liquid separation is sent into an adsorption tower from bottom to top through a pipeline and a program control valve for adsorption, the adsorbent in the adsorption tower adsorbs components above carbon two in the dry gas, and the unadsorbed hydrogen-rich methane gas is discharged from the top of the adsorption tower to the adsorption tower and is sent to a fuel gas pipe network or a hydrogen extraction device. And after the adsorption is finished, closing the program control valve for the catalytic dry gas to enter, stopping the catalytic dry gas from entering the adsorption tower, and stopping the adsorption.
(2) And (3) replacement: and (3) opening the replacement program control valve, returning part of the ethylene-rich concentrated gas to the adsorption tower for replacing the adsorption bed layer so as to improve the concentration of the components above the carbon two in the tower, and closing the replacement program control valve after replacement is finished.
(3) Pressure equalization and reduction:
and (3) opening the pressure equalization pressure reduction program control valve to enable the gas in the adsorption tower which finishes the adsorption step to enter the adsorption tower which finishes the evacuation step through the pressure equalization pressure increase program control valve along the adsorption direction until the pressure of 2 adsorption towers is consistent, so that the pressure in the adsorption tower which finishes the adsorption is reduced, and the ethylene ethane in the space of the adsorption tower is recovered.
(4) Reverse amplification: and opening the reverse-release program control valve, continuously reducing the pressure of the adsorption tower to be close to atmospheric pressure, discharging desorbed gas depressurized by the adsorption bed layer as ethylene-rich concentrated gas from the lower part of the adsorption tower, and closing the reverse-release program control valve after the reverse-release step is completed.
(5) Vacuumizing:
the pressure of an adsorption bed layer is further reduced by using a vacuum pump to the adsorption tower close to the normal pressure, air is pumped out to flow out of the adsorption tower as ethylene-rich concentrated gas, and the vacuum degree of the bed layer reaches-0.085 MPa in the step.
(6) Pressure balance rise
And (4) boosting the pressure of the adsorption tower after the evacuation step by using the hydrogen-rich methane gas flowing out of the top of the adsorption tower in the pressure equalization reduction step until the pressure of the two adsorption towers is consistent.
(7) Final boost
After the pressure equalization rising step is completed, the adsorption tower is continuously boosted by hydrogen-rich methane gas, and the pressure is raised to be close to the adsorption pressure for the next adsorption.
Each adsorption tower will go through the same steps, staggered in time sequence to ensure that the separation process is continuous.
In the utility model, after gas-liquid separation, the catalytic dry gas is firstly subjected to pressure swing adsorption unit consisting of adsorption, replacement, pressure equalization reduction, reverse release, evacuation and pressure boosting steps to remove most of hydrogen, oxygen, nitrogen and methane in the catalytic dry gas, and hydrocarbon components above the concentrated carbon dioxide are used to obtain ethylene-rich gas; the compression unit pressurizes the ethylene-rich concentrated gas to 0.8-2.0 MPag; then the wastewater enters a purification unit to remove carbon dioxide, sulfide, arsenic and mercury, nitrogen oxide and water; the purified gas enters a cryogenic rectification unit to separate ethylene and ethane, and the ethylene with the purity of more than 99.9 percent and the ethane with the purity of more than 98 percent are obtained.
The detailed process steps of the utility model are as follows:
(1) a pressure swing adsorption concentration unit: the catalytic dry gas after gas-liquid separation enters from the bottom of an adsorption tower of a pressure swing adsorption unit, and after the steps of adsorption, replacement, pressure equalization reduction, reverse discharge, evacuation, pressure boosting and the like, gas rich in hydrogen, oxygen, nitrogen, carbon monoxide and methane is obtained from the top of the adsorption tower and is used as a fuel or a raw material for hydrogen extraction, ethylene-rich concentrated gas is obtained from the lower part of the adsorption tower, and an ethylene-rich compressor is removed; the adsorption temperature is 25-40 ℃. The liquid separated in the gas-liquid separation mechanism is processed in other devices or steps.
(2) A compression unit: the ethylene-rich concentrated gas from the pressure swing adsorption unit is pressurized to 0.8-2.0 MPag by a compressor.
(3) A purification unit: the ethylene-rich concentrated gas from the compressor is purified and removed of impurities in the ethylene-rich concentrated gas through various working procedures in a purification unit. And a monoethanolamine or diethanolamine absorption procedure: and (2) feeding the ethylene concentrated gas from the lower part of the amine absorption tower, feeding the monoethanolamine or diethanolamine liquid from the upper part of the amine absorption tower, and removing most of carbon dioxide and hydrogen sulfide in the ethylene concentrated gas after the two material flows are fully contacted reversely, and then removing the refined sulfur.
A fine desulfurization process: the concentrated ethylene gas is passed through amine absorption step and fine desulfurizing step to eliminate sulfide, such as thioalcohol thioether, at normal temperature to lower sulfide content to 1.0mg/m3。
The arsenic and mercury removing process adopts arsenic and mercury removing agent to remove arsenic and mercury at normal temperature, so that the arsenic is less than or equal to 5.0 mu g/Kg and the mercury is less than or equal to 1.0 mu g/Kg.
The process of removing nitrogen oxide adopts catalyst hydrogenation to remove nitrogen oxide in the ethylene-rich concentrated gas, and makes its content be less than or equal to 10.0 microliter/m3。
An alkali absorption step: the ethylene concentrated gas reversely contacts with sodium hydroxide solution in an absorption tower, and carbon dioxide is removed to 1.0ml/m through sodium hydroxide absorption3。
A drying procedure: the ethylene concentrated gas is subjected to temperature swing adsorption in the drying process to remove water in the ethylene concentrated gas so as to enable the water to containThe amount is less than 1.0ml/m3. Avoiding the water from blocking the pipeline in the ethylene purification unit.
(4) A cryogenic rectification unit: the unit adopts CH4、C2H4、C3H6The mixture is used as a refrigerant, and the refrigerant is recycled. Cooling the ethylene concentrated gas, feeding the ethylene concentrated gas into a third decarbonizing tower, rectifying the ethylene concentrated gas to obtain mixed hydrocarbon at the tower bottom, feeding the tower top material flow into a demethanizer, removing oxyhydrogen methane components in the demethanizer, and extracting methane-rich gas from the tower top. And (3) feeding the demethanizer residue into an ethylene and ethane separation tower, and rectifying to obtain high-purity ethylene at the tower top. High-purity ethane is obtained at the bottom of the tower.
Test example 1
16000Nm of catalytic dry gas3The composition is shown in Table 1, the pressure is 0.7MPa and the temperature is 40 ℃.
TABLE 1 catalytic Dry gas composition (v%)
(1) Pressure swing adsorption unit
16000Nm after gas-liquid separation3The method comprises the steps of introducing catalytic dry gas into a pressure swing adsorption unit under the working condition that the pressure is 0.7MPag and the temperature is 40 ℃, allowing 8 adsorption towers to respectively undergo adsorption, replacement, pressure equalization reduction, reverse release, evacuation, pressure boosting and the like, adsorbing hydrocarbons with more than C2 components such as ethylene and ethane by using an adsorbent in the adsorption tower, discharging most of components such as nitrogen, oxygen, carbon monoxide, methane, a small amount of ethane and the like out of the adsorption tower from the top of the adsorption tower to a fuel gas pipe network or a hydrogen extraction device, and discharging desorbed gas subjected to pressure reduction by an adsorption bed layer as ethylene-rich concentrated gas from the lower part of the adsorption tower to enter a compressor.
(2) Compression unit
The hydrocarbon-rich concentrated gas of the pressure swing adsorption unit is compressed and pressurized to 1.7MPa by a compressor, and the condensate is separated and enters a purification unit.
(3) Purification unit
Monoethanolamine or diethanolamine absorption process
The method comprises the following steps that ethylene-rich concentrated gas from a compressor enters from the lower part of an amine absorption tower, monoethanolamine or diethanolamine liquid enters from the upper part of the amine absorption tower, and after two streams are fully contacted reversely, most of acidic substances such as carbon dioxide and hydrogen sulfide in the ethylene concentrated gas are removed, and then the ethylene concentrated gas is subjected to a fine desulfurization process.
Fine desulfurization process
The ethylene-rich concentrated gas enters a fine desulfurization process, and sulfides such as mercaptan sulfide and the like are removed by using a fine desulfurizing agent at normal temperature to ensure that the sulfides are less than or equal to 1.0mg/m3。
Dearsenifying and hydrargyrum removing procedure
The concentrated gas rich in ethylene enters the arsenic and mercury removal process through the fine desulfurization process, and arsenic and mercury are removed by using an arsenic removal mercurial agent at normal temperature, so that the arsenic is less than or equal to 5.0 mu g/Kg, and the mercury is less than or equal to 1.0 mu g/Kg.
Denitrification oxide process
The ethylene-rich concentrated gas enters a denitrogenation oxidation process through an arsenic and mercury removal process, and nitrogen oxides in the hydrocarbon-rich concentrated gas are removed by hydrogenation through a catalyst, so that the content of the nitrogen oxides is less than or equal to 10.0 mu l/m3。
Alkali absorption step
The ethylene-rich concentrated gas is reversely contacted with sodium hydroxide solution in an absorption tower, and is absorbed by two sections of alkali and then washed by water to remove carbon dioxide to 1.0ml/m3。
Drying step
The ethylene-rich concentrated gas is subjected to temperature swing adsorption to remove water in the ethylene-rich concentrated gas in 2 dryers, and the content of water in the ethylene-rich concentrated gas is less than or equal to 1.0ml/m through continuous cycle operation of adsorption regeneration3。
(4) Cryogenic rectification unit
The unit adopts CH4、C2H4、C3H6The mixture is used as a refrigerant, and the refrigerant is recycled. The concentrated ethylene gas is cooled and then enters a three-decarbonization tower, the mixed hydrocarbon is obtained at the bottom of the tower after rectification, the material flow at the top of the tower enters a demethanizer, the oxyhydrogen methane component is removed in the demethanizer, and the methane-rich gas is pumped out from the top of the tower and enters other devices. The demethanizer bottoms enter an ethylene and ethane separation tower, high-purity ethylene shown in the table 2 is obtained at the tower top through rectification, and ethane with the purity of more than 98% is obtained at the tower bottom.
TABLE 2 ethylene product gas Specification (v%)
| CH4 | CO | CO2 | C2H6 | C2H4 | S mg/m3 | H20ml/m3 | As,μg/Kg | Hg,μg/Kg | NOxml/m3 |
| 0.026 | 0.0002 | 0.0005 | 0.0161 | 99.957 | ≤1.0 | ＜1.0 | ＜5.0 | ＜1.0 | ＜10 |
Compared with the patents disclosed in Chinese patent ZL00113109.5, such as 'method for separating and recovering ethylene, ethane, propylene and hydrogen from hydrocarbon-containing mixed gas', the method has the advantages that (firstly) raw material catalytic dry gas is not required to be pressurized; secondly, the pressure for pressurizing the ethylene-rich concentrated gas after the pressure swing adsorption unit is low; thirdly, the purifying unit only processes the ethylene-rich concentrated gas with little gas; the operation temperature of the desulfurization and dearsenification mercury unit is normal temperature, so the energy consumption is greatly reduced.
The basic principles and main features of the present invention and the advantages of the present invention have been shown and described above, and the above embodiments and description have been described only to illustrate the principles of the present invention without departing from the spirit and scope of the present invention, which will also have various changes and modifications, all of which will fall within the scope of the claimed invention. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (7)
1. A device system for separating ethylene and ethane in catalytic dry gas is characterized in that: the device is provided with a gas-liquid separation mechanism, a pressure swing adsorption mechanism, a compression mechanism, a purification mechanism and a cryogenic rectification mechanism, wherein the gas-liquid separation mechanism is connected with the pressure swing adsorption mechanism, the pressure swing adsorption mechanism is connected with the compression mechanism, the compression mechanism is connected with the purification mechanism, and the purification mechanism is connected with the cryogenic rectification mechanism; all the mechanisms are connected into a whole through pipelines.
2. The system of claim 1, wherein the system comprises: the pressure swing adsorption mechanism is formed by connecting 5 or more than 5 adsorbers in parallel into a whole, and each adsorber is internally provided with an adsorbent.
3. The system of claim 1, wherein the system comprises: the purification mechanism is provided with an amine absorption tower, a fine desulfurization tower, an arsenic removal mercury tower, a denitrogenation oxide tower, an alkali absorption tower and a drying tower, wherein the amine absorption tower is connected with the fine desulfurization tower; the towers are connected into a whole through pipelines.
4. The apparatus system of claim 3, wherein the apparatus system for separating ethylene and ethane from the catalytic dry gas comprises: the compressor is connected with the lower part of the amine absorption tower, and the top end part of the amine absorption tower is connected with the fine desulfurization tower.
5. The apparatus system of claim 3, wherein the apparatus system for separating ethylene and ethane from the catalytic dry gas comprises: the drying procedure comprises connecting more than 2 driers in series to remove water in the ethylene concentrated gas.
6. The system of claim 1, wherein the system comprises: the low-temperature rectification mechanism is provided with a refrigeration system, a decarburization three tower, a demethanizer and a separation ethylene and ethane tower, the drying tower is connected with the refrigeration system, the refrigeration system is connected with the decarburization three tower, the top end part of the decarburization three tower is connected with the demethanizer, the demethanizer is connected with the separation ethylene and ethane tower, methane-rich gas is output from the demethanizer, mixed hydrocarbon is output from the lower part of the decarburization three tower, high-purity ethylene is output from the top end part of the separation ethylene and ethane tower, and ethane is output from the lower part of the separation ethylene and ethane tower.
7. The apparatus system of claim 6, wherein the apparatus system for separating ethylene and ethane from the catalytic dry gas comprises: the refrigeration system is a refrigerator.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022855810.9U CN213977484U (en) | 2020-12-02 | 2020-12-02 | Device system for separating ethylene and ethane in catalytic dry gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202022855810.9U CN213977484U (en) | 2020-12-02 | 2020-12-02 | Device system for separating ethylene and ethane in catalytic dry gas |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN213977484U true CN213977484U (en) | 2021-08-17 |
Family
ID=77239208
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202022855810.9U Active CN213977484U (en) | 2020-12-02 | 2020-12-02 | Device system for separating ethylene and ethane in catalytic dry gas |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN213977484U (en) |
-
2020
- 2020-12-02 CN CN202022855810.9U patent/CN213977484U/en active Active
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN105749699B (en) | Full-temperature-range pressure swing adsorption gas separation, purification and purification method | |
| CN107789949B (en) | Gas separation method by negative pressure swing adsorption | |
| CN107433107B (en) | Two-stage concentration PSA method for recovering C2+ from refinery dry gas | |
| CN104030875B (en) | High yield highly purified catalytic cracked dry gas sharp separation process for purification and device | |
| CN103450941A (en) | Method for producing ethylene cracking raw material from coking dry gas | |
| US11760632B2 (en) | Regeneration schemes for a two-stage adsorption process for Claus tail gas treatment | |
| CN107778124B (en) | Full-temperature range adsorption extraction separation method for recovering H2 and C2+ from refinery dry gas | |
| CN113200518A (en) | Method for recovering and purifying hydrogen from semi-coke tail gas | |
| CN102659104B (en) | Process for extracting carbon dioxide and hydrogen jointly by decarburization-pressure swing adsorption of shift gas | |
| CN113184850A (en) | Method and device for purifying high-purity carbon dioxide gas | |
| CN112521245A (en) | Method for producing high-purity ethylene | |
| CN109502547B (en) | Method for separating and purifying hydrogen from refinery tail gas | |
| CN112374959B (en) | Method for separating ethylene and ethane in catalytic dry gas | |
| CN102659105B (en) | Technology for extracting carbon dioxide and hydrogen by combining medium temperature shift gas decarbonization-stationary bed-pressure swing adsorption | |
| CN213977484U (en) | Device system for separating ethylene and ethane in catalytic dry gas | |
| CN1273374C (en) | Technology of combined extreacting carbon dioxide and hydrogen using medium varying gas decarbonization-varying pressure adsorption | |
| CN209052640U (en) | It is a kind of to utilize coke-stove gas synthesis of methanol with joint production LNG, richness H2Device | |
| CN111548824A (en) | Combined process for recovering and separating refinery dry gas | |
| CN112723976A (en) | Method and system for recycling refinery dry gas as ethylene raw material by using metal organic framework material | |
| CN114712984B (en) | Substitution process for recycling CO2 through full-temperature-range pressure swing adsorption for amine absorption decarburization in natural gas SMB hydrogen production | |
| CN214088345U (en) | Device system for producing high-purity ethylene | |
| CN212492394U (en) | Device system for recovering nitrogen in polyethylene device flare gas | |
| CN210030042U (en) | Decarbonization gas hydrogen stripping system | |
| CN108014598A (en) | One kind removes non-methane hydrocarbon and recycling C in broken coal low-temperature methanol washing tail-gas2+The system and method for hydrocarbon | |
| CN113735079A (en) | Method for extracting ultra-high purity helium gas at normal temperature and production device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| GR01 | Patent grant | ||
| GR01 | Patent grant |