CN116143576A - Heat removal method and heat removal system for reaction of preparing alpha-olefin by ethylene selective polymerization - Google Patents
Heat removal method and heat removal system for reaction of preparing alpha-olefin by ethylene selective polymerization Download PDFInfo
- Publication number
- CN116143576A CN116143576A CN202310182571.0A CN202310182571A CN116143576A CN 116143576 A CN116143576 A CN 116143576A CN 202310182571 A CN202310182571 A CN 202310182571A CN 116143576 A CN116143576 A CN 116143576A
- Authority
- CN
- China
- Prior art keywords
- ethylene
- gas
- polymerization reaction
- solvent
- heat removal
- 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.)
- Pending
Links
- 239000005977 Ethylene Substances 0.000 title claims abstract description 208
- VGGSQFUCUMXWEO-UHFFFAOYSA-N Ethene Chemical compound C=C VGGSQFUCUMXWEO-UHFFFAOYSA-N 0.000 title claims abstract description 206
- 238000006243 chemical reaction Methods 0.000 title claims abstract description 181
- 238000006116 polymerization reaction Methods 0.000 title claims abstract description 145
- 238000000034 method Methods 0.000 title claims abstract description 59
- 239000004711 α-olefin Substances 0.000 title claims abstract description 42
- 239000007788 liquid Substances 0.000 claims abstract description 134
- 238000001816 cooling Methods 0.000 claims abstract description 108
- 239000002904 solvent Substances 0.000 claims abstract description 107
- 238000000926 separation method Methods 0.000 claims abstract description 88
- 239000001273 butane Substances 0.000 claims abstract description 66
- IJDNQMDRQITEOD-UHFFFAOYSA-N n-butane Chemical compound CCCC IJDNQMDRQITEOD-UHFFFAOYSA-N 0.000 claims abstract description 66
- OFBQJSOFQDEBGM-UHFFFAOYSA-N n-pentane Natural products CCCCC OFBQJSOFQDEBGM-UHFFFAOYSA-N 0.000 claims abstract description 66
- 239000002994 raw material Substances 0.000 claims abstract description 60
- 230000008569 process Effects 0.000 claims abstract description 29
- 239000012071 phase Substances 0.000 claims description 122
- 238000009833 condensation Methods 0.000 claims description 72
- 230000005494 condensation Effects 0.000 claims description 72
- 239000007791 liquid phase Substances 0.000 claims description 55
- 239000011259 mixed solution Substances 0.000 claims description 46
- 238000010521 absorption reaction Methods 0.000 claims description 28
- 230000001105 regulatory effect Effects 0.000 claims description 23
- 239000002826 coolant Substances 0.000 claims description 21
- LIKMAJRDDDTEIG-UHFFFAOYSA-N 1-hexene Chemical compound CCCCC=C LIKMAJRDDDTEIG-UHFFFAOYSA-N 0.000 claims description 20
- KWKAKUADMBZCLK-UHFFFAOYSA-N 1-octene Chemical compound CCCCCCC=C KWKAKUADMBZCLK-UHFFFAOYSA-N 0.000 claims description 20
- VXNZUUAINFGPBY-UHFFFAOYSA-N 1-Butene Chemical compound CCC=C VXNZUUAINFGPBY-UHFFFAOYSA-N 0.000 claims description 12
- 238000003756 stirring Methods 0.000 claims description 11
- TVMXDCGIABBOFY-UHFFFAOYSA-N n-Octanol Natural products CCCCCCCC TVMXDCGIABBOFY-UHFFFAOYSA-N 0.000 claims description 10
- AFFLGGQVNFXPEV-UHFFFAOYSA-N 1-decene Chemical compound CCCCCCCCC=C AFFLGGQVNFXPEV-UHFFFAOYSA-N 0.000 claims description 8
- CRSBERNSMYQZNG-UHFFFAOYSA-N 1-dodecene Chemical compound CCCCCCCCCCC=C CRSBERNSMYQZNG-UHFFFAOYSA-N 0.000 claims description 8
- 230000000379 polymerizing effect Effects 0.000 claims description 7
- 230000017525 heat dissipation Effects 0.000 claims description 6
- 229940069096 dodecene Drugs 0.000 claims description 4
- 238000012545 processing Methods 0.000 claims description 4
- 238000010992 reflux Methods 0.000 claims description 4
- 238000006384 oligomerization reaction Methods 0.000 abstract description 12
- 238000004519 manufacturing process Methods 0.000 abstract description 11
- 230000008901 benefit Effects 0.000 abstract description 8
- 239000007789 gas Substances 0.000 description 154
- 239000003054 catalyst Substances 0.000 description 11
- 229920000642 polymer Polymers 0.000 description 10
- 239000007787 solid Substances 0.000 description 10
- 230000000694 effects Effects 0.000 description 8
- 230000001276 controlling effect Effects 0.000 description 6
- 238000005516 engineering process Methods 0.000 description 6
- 239000007792 gaseous phase Substances 0.000 description 6
- 230000009471 action Effects 0.000 description 4
- 239000000243 solution Substances 0.000 description 4
- 239000004698 Polyethylene Substances 0.000 description 3
- 238000002156 mixing Methods 0.000 description 3
- 230000006978 adaptation Effects 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- JRPSMDMQPAEKFW-UHFFFAOYSA-N butane;ethene Chemical compound C=C.CCCC JRPSMDMQPAEKFW-UHFFFAOYSA-N 0.000 description 2
- 239000007810 chemical reaction solvent Substances 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 229920001903 high density polyethylene Polymers 0.000 description 2
- 239000004700 high-density polyethylene Substances 0.000 description 2
- 238000012986 modification Methods 0.000 description 2
- 230000004048 modification Effects 0.000 description 2
- 229920006124 polyolefin elastomer Polymers 0.000 description 2
- 238000003786 synthesis reaction Methods 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 238000012546 transfer Methods 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 229920010126 Linear Low Density Polyethylene (LLDPE) Polymers 0.000 description 1
- 150000001336 alkenes Chemical class 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000013064 chemical raw material Substances 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 238000011161 development Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000012847 fine chemical Substances 0.000 description 1
- 230000008570 general process Effects 0.000 description 1
- 239000010687 lubricating oil Substances 0.000 description 1
- 239000003921 oil Substances 0.000 description 1
- 235000019198 oils Nutrition 0.000 description 1
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 229920000098 polyolefin Polymers 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000007670 refining Methods 0.000 description 1
- 239000003507 refrigerant Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 235000015112 vegetable and seed oil Nutrition 0.000 description 1
- 239000008158 vegetable oil Substances 0.000 description 1
- 238000004804 winding Methods 0.000 description 1
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2/00—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms
- C07C2/02—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition between unsaturated hydrocarbons
- C07C2/04—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition between unsaturated hydrocarbons by oligomerisation of well-defined unsaturated hydrocarbons without ring formation
- C07C2/06—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by addition between unsaturated hydrocarbons by oligomerisation of well-defined unsaturated hydrocarbons without ring formation of alkenes, i.e. acyclic hydrocarbons having only one carbon-to-carbon double bond
- C07C2/08—Catalytic processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0006—Controlling or regulating processes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0006—Controlling or regulating processes
- B01J19/0013—Controlling the temperature of the process
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J19/00—Chemical, physical or physico-chemical processes in general; Their relevant apparatus
- B01J19/0053—Details of the reactor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J4/00—Feed or outlet devices; Feed or outlet control devices
- B01J4/001—Feed or outlet devices as such, e.g. feeding tubes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J4/00—Feed or outlet devices; Feed or outlet control devices
- B01J4/008—Feed or outlet control devices
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Polymerisation Methods In General (AREA)
Abstract
The invention provides a heat removal process and a heat removal system for a reaction for preparing alpha-olefin by ethylene selective polymerization. The process for preparing the alpha-olefin by ethylene selective polymerization has the characteristic of remarkable economic benefit, but the reaction of the process is a strong exothermic reaction, and the effective withdrawal of the reaction heat is the key point and the difficulty of the process. The invention utilizes the combination of raw material low-temperature feeding and gas-phase external circulation to withdraw the ethylene selective polymerization reaction heat, cools the ethylene and butane solvent, uniformly mixes the cooled ethylene and butane solvent and enters a reaction kettle for reaction, utilizes the ethylene gas-phase external circulation to carry a large amount of butane, the butane flows back to the reaction kettle for cooling when encountering cold, and simultaneously the rest gas phase returns to the kettle through a circulating gas compressor, a circulating gas cooler and a gas-liquid separation tank in sequence, thereby taking away the polymerization reaction heat, and a plurality of efficient heat removal modes coexist, thereby achieving the aim of stably controlling the reaction temperature of the reaction kettle. The heat removal method provided by the invention can quickly and efficiently remove the reaction heat in the reaction kettle of the polymerization reaction, thereby ensuring that the ethylene selective oligomerization reaction is stably carried out.
Description
Technical Field
The invention belongs to the technical field of thermodynamic cycle of an alpha-olefin reaction prepared by ethylene selective polymerization, relates to a heat removal process and a heat removal system of the alpha-olefin reaction prepared by ethylene selective polymerization, and particularly relates to a heat removal method and a heat removal system of the alpha-olefin reaction prepared by ethylene selective polymerization.
Background
The linear alpha-olefin is an important organic chemical raw material and an intermediate, can be used as an ethylene comonomer, and can also be used as raw materials for producing fine chemicals such as high-end lubricating oil, plasticizer alcohol, surfactant and the like. Among them, low molecular weight linear alpha-olefins (such as 1-butene, 1-hexene, 1-octene, etc.) are mainly used as ethylene comonomers for the production of high performance Linear Low Density Polyethylene (LLDPE), high Density Polyethylene (HDPE), and polyolefin elastomers (POE) to improve impact resistance, tensile resistance, tear resistance, etc. of polymers. In recent years, with the continued development of the polyolefin industry, the worldwide demand for α -olefins has grown rapidly.
According to different production processes, the production technology of linear alpha-olefin mainly comprises a wax cracking method, a mixed C4 separation method, an ethylene oligomerization process, an ethylene selective polymerization process, a Fischer-Tropsch synthesis (F-T) method, a vegetable oil method and the like. At present, the technology is basically eliminated because of the laggard technology of the wax cracking method and poor product quality. The raw materials of the mixed C4 separation technology are supported by a refining device of an oil refinery, and the target product is only 1-butene. Fischer-Tropsch synthesis relies on abundant coal resources, and the product has complex components and high separation cost, and is difficult to obtain high-purity single-component olefin. Thus, over 80% of the worldwide linear alpha-olefins are produced by ethylene selective polymerization processes and ethylene oligomerization processes.
The ethylene selective polymerization technology has the characteristics of high catalyst activity and high target product selectivity, and becomes a key technology for industrially producing low-carbon linear alpha-olefin. The ethylene selective polymerization reaction is a strong exothermic reaction, and the target product selectivity is poor and even the catalyst is deactivated due to the overtemperature reaction of the reaction kettle. Meanwhile, part of solid polymer is generated in the reaction, so that the solid polymer in the reaction kettle is prevented from winding and staying, the conventional condensing coil is not suitable for heat removal in the reaction kettle, the heat removal is difficult only by the jacket, and the effective withdrawal of the reaction heat in the reaction kettle is difficult to ensure.
Therefore, how to find a high-efficiency heat removal method for preparing alpha-olefin by ethylene selective polymerization, so as to quickly withdraw the heat of ethylene selective polymerization reaction from a reaction kettle, ensure long-period stable operation of the device, and become one of the technical problems to be solved by a plurality of first-line researchers in the technical field.
Disclosure of Invention
In view of the above, the technical problem to be solved by the present invention is to provide a heat removal process and a heat removal system for a reaction for producing α -olefins by selectively polymerizing ethylene. The heat removal method for the reaction for preparing the alpha-olefin by selectively polymerizing the ethylene can efficiently and quickly remove the heat of polymerization, and solves the technical problem that the heat of the reaction for preparing the alpha-olefin by selectively polymerizing the ethylene is difficult to remove from a reaction kettle in the prior art.
The invention provides a heat removal process for preparing alpha-olefin by ethylene selective polymerization, which comprises the steps of raw material heat removal and polymerization reaction device gas phase heat removal;
the heat removal of the raw materials comprises the following steps:
1) Cooling an ethylene raw material by an ethylene cooling device, and then entering an absorption device;
after being cooled by a solvent cooling device, the solvent is also sent into an absorption device and is uniformly mixed with ethylene to obtain a mixed solution;
2) Introducing the mixed solution obtained in the steps into a mixed solution buffer device, and then introducing the mixed solution into a polymerization reaction device;
the gas phase heat removal of the polymerization reaction device comprises the following steps:
and (3) carrying out external circulation on the gas phase of the polymerization reaction device, firstly sending the gas phase into a condensation liquid separation device for condensation liquid separation, then processing the liquid separated gas phase by a circulating gas compressor, then sending the gas phase into a circulating gas cooling device for cooling, then sending the gas phase into a gas-liquid separation device for gas-liquid separation, and finally respectively returning the gas phase and the liquid phase after gas-liquid separation to the polymerization reaction device.
Preferably, the alpha-olefin comprises one or more of 1-butene, 1-hexene, 1-octene, 1-decene, and 1-dodecene;
the solvent comprises butane;
the ethylene raw material is cooled by an ethylene cooling device, namely, the ethylene raw material is introduced into a tube side of the ethylene cooling device, and a cooling medium is introduced into a shell side of the ethylene cooling device;
the temperature of the ethylene raw material after passing through the ethylene cooling device is-20-5 ℃.
Preferably, the solvent is cooled by the solvent cooling device, namely, the solvent is introduced into a tube side of the solvent cooling device, and the cooling medium is introduced into a shell side of the solvent cooling device;
the temperature of the solvent after passing through the solvent cooling device is-30-20 ℃;
the mass ratio of the ethylene to the solvent is (10-50): 100;
the gas phase comprises ethylene and butane.
Preferably, the upper part of the condensation liquid separating device is provided with a condensation coil, and a cooling medium is connected into the coil;
the gas phase is sent to the middle lower part of the condensation liquid separating device;
after the condensation and liquid separation, the liquefied liquid phase returns to the polymerization reaction device;
the liquid phase comprises butane;
the liquid phase reflux amount returned to the polymerization reaction apparatus is controlled based on the temperature of the polymerization reaction apparatus.
Preferably, the volume ratio of the gas phase circulation amount per hour of the external circulation to the ethylene feed amount per hour of the polymerization reaction device is (2-10): 1, a step of;
the gas phase is sent to a tube side of the circulating gas cooling device after being processed by a circulating gas compressor, and a cooling medium is introduced to a shell side of the circulating gas cooling device;
the temperature of the cooling medium is-20 ℃;
the ratio of the gas phase and the liquid phase after the gas-liquid separation returned to the polymerization reaction device is controlled based on the temperature of the polymerization reaction device;
the volume ratio of the gas phase and the liquid phase after gas-liquid separation returned to the polymerization reaction device is (2-10): 1.
the invention also provides a heat removal system for the reaction of preparing alpha-olefin by ethylene selective polymerization, wherein the heat removal device comprises a raw material heat removal system and a polymerization reaction device gas phase heat removal system;
the raw material heat removal system comprises:
an ethylene cooling unit connected to an ethylene feed source;
a solvent cooling device connected to a solvent feed source;
absorption means connected to said ethylene cooling means and said solvent cooling means;
a mixed liquid buffer device connected with the absorption device;
the mixed solution buffer device is connected with the polymerization reaction device;
the polymerization reaction device gas phase heat removal system comprises:
a polymerization reaction device;
the condensation liquid separation device is connected with the polymerization reaction device;
a recycle gas compressor connected with the condensation liquid separation device;
the circulating gas cooling device is connected with the circulating gas compressor;
the gas-liquid separation device is connected with the circulating gas cooling device;
the gas phase outlet and the liquid phase outlet of the gas-liquid separation device are respectively connected with the polymerization reaction device.
Preferably, an ethylene flow regulator is further arranged between the ethylene feed source pipeline and the ethylene cooling device;
a solvent flow regulator is also arranged between the solvent feed source pipeline and the solvent cooling device;
the ethylene cooling device comprises a shell and tube cooler;
and the outlet of the ethylene flow regulator is connected with the tube side of the ethylene cooling device.
Preferably, the solvent cooling device comprises a shell and tube cooler;
the outlet of the solvent flow regulator is connected with the tube side of the solvent cooling device;
the upper part of the condensation liquid separation device is provided with a condensation coil;
the cold medium pipeline is connected into a condensing coil of the condensing liquid-separating device;
the height-diameter ratio of the condensation liquid separating device is (5-10): 1.
preferably, a circulating gas phase outlet of the polymerization reaction device is connected with a gas phase inlet at the middle lower part of the condensation liquid separation device;
a gas phase connecting pipeline of the condensation liquid separation device and the polymerization reaction device is provided with a flow regulating device;
the liquid phase outlet of the condensation liquid separation device is connected with the polymerization reaction device;
and a liquid phase flow regulating device is arranged on a liquid phase connecting pipeline of the condensation liquid separating device and the polymerization reaction device.
Preferably, the gas phase outlet of the circulating gas compressor is connected with the tube side of the circulating gas cooling device;
a gas phase flow regulating device is arranged on a pipeline connected with the polymerization reaction device at a gas phase outlet of the gas-liquid separation device;
a liquid phase flow regulating device is arranged on a pipeline connected with the polymerization reaction device at a liquid phase outlet of the gas-liquid separation device;
one or more of a heat dissipation jacket, a stirring paddle and a temperature sensor are arranged on the polymerization reaction device.
The invention provides a heat removal process for preparing alpha-olefin by ethylene selective polymerization, which comprises the steps of raw material heat removal and polymerization reaction device gas phase heat removal; the raw material heat removal comprises the following steps that firstly, an ethylene raw material is cooled by an ethylene cooling device and then enters an absorption device; after being cooled by a solvent cooling device, the solvent is also sent into an absorption device and is uniformly mixed with ethylene to obtain a mixed solution; then the mixed solution obtained in the steps is introduced into a mixed solution buffer device and then is introduced into a polymerization reaction device; the gas phase heat removal of the polymerization reaction device comprises the following steps of externally circulating the gas phase of the polymerization reaction device, firstly sending the gas phase into a condensation liquid separation device for condensation liquid separation, then sending the separated gas phase into a circulating gas cooling device for cooling after the gas phase is treated by a circulating gas compressor, then sending the gas phase into a gas-liquid separation device for gas-liquid separation, and finally respectively returning the gas phase and the liquid phase after the gas-liquid separation to the polymerization reaction device. Compared with the prior art, the heat removal method of the invention is mainly divided into two parts, namely, a raw material heat removal part: the raw material ethylene and the solvent are cooled by a cooler respectively, and the low-temperature raw material and the solvent are mixed uniformly and then enter a reaction kettle. The other part is a gas phase external circulation heat removal part of the reaction kettle: the reaction kettle is used for ethylene selective oligomerization reaction, a condensing liquid separating tank communicated with the reaction kettle, a circulating gas compressor connected with the condensing liquid separating tank, a cooler connected with the circulating gas compressor, and a gas-liquid separating tank connected with the cooler, wherein gas phase and liquid phase of the gas-liquid separating tank are both communicated with the reaction kettle. The process for preparing alpha-olefin (including 1-hexene, 1-octene, etc.) by ethylene selective polymerization is a hot spot studied in recent years and has the characteristic of remarkable economic benefit, the reaction of the process is a strong exothermic reaction, and the effective withdrawal of the reaction heat is the key point and the difficulty of the process. The heat removal method provided by the invention can quickly and efficiently remove the reaction heat in the reaction kettle of the polymerization reaction, thereby ensuring that the ethylene selective oligomerization reaction is stably carried out.
The invention provides a heat removal method and a heat removal system, which mainly comprise the steps that raw materials of ethylene and butane solvent enter respective coolers through a flow controller according to a certain proportion to cool, after the temperature is reduced to a certain temperature, the ethylene and butane are uniformly mixed at an absorption tank, ethylene butane mixed solution enters a mixed solution buffer tank to be buffered, the mixed solution is pressurized by a pump and enters a reaction kettle, low-temperature raw materials are in direct contact with reaction solution in the reaction kettle, part of reaction heat can be removed, and meanwhile, the ethylene in butane is gasified and rapidly removed. The butane solvent is carried in the gaseous phase ethylene from the top of the reaction kettle into a condensation liquid separating tank, most butane is cooled at a condensing coil pipe at the upper part of the condensation liquid separating tank and then returned to the reaction kettle from the bottom, partial butane carried in the gaseous phase ethylene comes out from the top of the condensation pipe, the gaseous phase ethylene enters a gas-liquid separation tank after being pressurized and cooled by a compressor and a cooler in sequence, uncondensed ethylene gas returns to the reaction kettle through the top of the condensation liquid separating tank, butane and partial liquefied ethylene return to the reaction kettle from the bottom of the condensation liquid separating tank, the proportion of gas phase and liquid phase in the condensation liquid separating tank can be regulated and controlled according to the temperature in the reaction kettle, the ethylene carries butane and returns to the reaction kettle after being cooled circularly, most of reaction heat in the reaction kettle can be withdrawn, and the reaction kettle is further provided with a cooling jacket and a stirring paddle, so that the effective withdrawal of ethylene selective polymerization reaction heat in the reaction kettle and stable operation of the device are further ensured. The heat removal process provided by the invention has the advantages that the process flow is simple, a plurality of heat removal modes coexist, butane is adopted as a reaction solvent, the property that butane is easy to vaporize and liquefy is utilized, the gas-phase external circulation heat removal capacity of the reaction kettle is increased, the work load of a circulating air compressor is reduced, and meanwhile, the heat removal modes of raw material low-temperature feeding and a heat dissipation jacket of the reaction kettle are adopted, so that the ethylene selective polymerization reaction heat can be rapidly and efficiently removed from the reaction kettle, and the polymerization reaction is ensured to run stably in the reaction kettle.
Experimental results show that the heat removal method and the heat removal system provided by the invention are adopted to run experiments on the reaction of preparing alpha-olefin by ethylene selective oligomerization of 400 tons/year, ethylene and solvent are mixed at low temperature and then fed, a jacket of a reaction kettle is used for controlling the temperature, and when the gas phase external circulation quantity is about 600kg/h, the polymerization reaction heat in the reaction kettle can be completely removed, the temperature of the reaction kettle is ensured to be stable, and the long-period stable running of the device is ensured. If the reaction kettle is not timely removed, the reaction kettle can be overheated, so that a large amount of solids are generated, and the long-period operation of the reaction kettle is seriously verified to be influenced.
Drawings
FIG. 1 is a schematic and schematic illustration of the process flow for the heat removal of the reaction for producing alpha-olefins by the selective polymerization of ethylene provided by the invention.
Detailed Description
For a further understanding of the present invention, preferred embodiments of the invention are described below in conjunction with the examples, but it should be understood that these descriptions are merely intended to illustrate further the features and advantages of the invention and are not limiting of the patent claims of the invention.
All the raw materials of the present invention are not particularly limited in their sources, and may be purchased on the market or prepared according to conventional methods well known to those skilled in the art.
The purity of all the raw materials of the present invention is not particularly limited, and the present invention is preferably carried out with a conventional purity in the field of industrial purity or ethylene selective polymerization production.
All processes and equipment of the present invention, the abbreviations thereof are conventional in the art, each abbreviation is clearly understood within the art of its associated use, and the skilled artisan will understand the general process steps and equipment configuration thereof based on the abbreviations.
The invention provides a heat removal process for preparing alpha-olefin by ethylene selective polymerization, which comprises the steps of raw material heat removal and polymerization reaction device gas phase heat removal;
the heat removal of the raw materials comprises the following steps:
1) Cooling an ethylene raw material by an ethylene cooling device, and then entering an absorption device;
after being cooled by a solvent cooling device, the solvent is also sent into an absorption device and is uniformly mixed with ethylene to obtain a mixed solution;
2) Introducing the mixed solution obtained in the steps into a mixed solution buffer device, and then introducing the mixed solution into a polymerization reaction device;
the gas phase heat removal of the polymerization reaction device comprises the following steps:
and (3) carrying out external circulation on the gas phase of the polymerization reaction device, firstly sending the gas phase into a condensation liquid separation device for condensation liquid separation, then processing the liquid separated gas phase by a circulating gas compressor, then sending the gas phase into a circulating gas cooling device for cooling, then sending the gas phase into a gas-liquid separation device for gas-liquid separation, and finally respectively returning the gas phase and the liquid phase after gas-liquid separation to the polymerization reaction device.
Firstly, cooling an ethylene raw material by an ethylene cooling device, and then, feeding the cooled ethylene raw material into an absorption device;
after being cooled by a solvent cooling device, the solvent is also sent into an absorption device and is uniformly mixed with ethylene to obtain a mixed solution;
in the present invention, the α -olefin preferably includes one or more of 1-butene, 1-hexene, 1-octene, 1-decene, and 1-dodecene, more preferably 1-butene, 1-hexene, 1-octene, 1-decene, or 1-dodecene.
In the present invention, the solvent preferably includes butane.
In the present invention, the ethylene raw material is cooled by the ethylene cooling device, preferably, the ethylene raw material is introduced into the tube side of the ethylene cooling device, and the cooling medium is introduced into the shell side of the ethylene cooling device.
In the present invention, the temperature of the ethylene raw material after passing through the ethylene cooling apparatus is preferably-20 to 5 ℃, more preferably-15 to 0 ℃, and still more preferably-10 to-5 ℃.
In the present invention, the solvent is cooled by the solvent cooling device, preferably, the solvent is introduced into the tube side of the solvent cooling device, and the cooling medium is introduced into the shell side of the solvent cooling device.
In the present invention, the temperature of the solvent after passing through the solvent cooling device is preferably-30 to 20 ℃, more preferably-20 to 10 ℃, and still more preferably-10 to 0 ℃.
In the present invention, the mass ratio of the ethylene to the solvent is preferably (10 to 50): 100, more preferably (15 to 45): 100, more preferably (20 to 40): 100, more preferably (25 to 35): 100.
the mixed solution obtained in the steps is introduced into a mixed solution buffer device and then is introduced into a polymerization reaction device;
the gas phase heat removal of the polymerization reaction device comprises the following steps:
and (3) carrying out external circulation on the gas phase of the polymerization reaction device, firstly sending the gas phase into a condensation liquid separation device for condensation liquid separation, then processing the liquid separated gas phase by a circulating gas compressor, then sending the gas phase into a circulating gas cooling device for cooling, then sending the gas phase into a gas-liquid separation device for gas-liquid separation, and finally respectively returning the gas phase and the liquid phase after gas-liquid separation to the polymerization reaction device.
In the invention, the upper part of the condensation liquid separating device is preferably provided with a condensation coil, and a cooling medium is connected into the coil.
In the present invention, the gas phase is preferably fed to the middle lower part of the condensate separating device.
In the present invention, the gas phase preferably includes ethylene and butane.
In the present invention, the liquefied liquid phase is preferably returned to the polymerization reaction apparatus after the condensed liquid is separated.
In the present invention, the liquid phase preferably comprises butane.
In the present invention, the liquid phase reflux amount to the polymerization reaction apparatus is preferably controlled based on the temperature of the polymerization reaction apparatus.
In the present invention, an external circulation of gas phase is established before the normal reaction feeding, and the gas phase circulation amount per hour of the external circulation is 2 to 10 times of the ethylene feeding amount per hour of the polymerization reaction device. Namely, the ratio by volume of the gas phase circulation amount per hour of the external circulation to the ethylene feed amount per hour of the polymerization reaction apparatus is preferably (2 to 10): 1, more preferably (3 to 9): 1, more preferably (5 to 7): 1.
in the present invention, the gas phase sent to the circulating gas cooling device is cooled, preferably, after being processed by the circulating gas compressor, sent to the tube side of the circulating gas cooling device, and the cooling medium is introduced into the shell side of the circulating gas cooling device
In the present invention, the temperature of the cooling medium is preferably-20 to 20 ℃, more preferably-10 to 10 ℃, and still more preferably 0 to 1 ℃.
In the present invention, the ratio of the gas phase and the liquid phase after the gas-liquid separation returned to the polymerization reactor is preferably controlled based on the temperature of the polymerization reactor.
In the present invention, the volume ratio of the gas phase and the liquid phase after the gas-liquid separation returned to the polymerization reaction apparatus is preferably (2 to 10): 1, more preferably (3 to 9): 1, more preferably (5 to 7): 1.
in the present invention, the selective polymerization includes selective oligomerization.
According to the method for removing the ethylene selective polymerization reaction heat by utilizing the combination of the raw material low-temperature feeding and the gas-phase external circulation, the ethylene and butane solvent are cooled and then uniformly mixed into the reaction kettle to react, a large amount of butane is carried in the ethylene gas-phase external circulation, the butane flows back to the reaction kettle to cool when encountering cold, and meanwhile, the rest gas phase sequentially returns to the reaction kettle through the circulating gas compressor, the circulating gas cooler and the gas-liquid separation tank, so that the polymerization reaction heat is taken away, various efficient heat removing modes coexist, and the aim of stably controlling the reaction temperature of the reaction kettle is fulfilled.
The invention provides a heat removal system for the reaction of preparing alpha-olefin by ethylene selective polymerization, which comprises a raw material heat removal system and a gas phase heat removal system of a polymerization reaction device.
The raw material heat removal system comprises:
an ethylene cooling unit connected to an ethylene feed source;
a solvent cooling device connected to a solvent feed source;
absorption means connected to said ethylene cooling means and said solvent cooling means;
a mixed liquid buffer device connected with the absorption device;
the mixed solution buffer device is connected with the polymerization reaction device;
the polymerization reaction device gas phase heat removal system comprises:
a polymerization reaction device;
the condensation liquid separation device is connected with the polymerization reaction device;
a recycle gas compressor connected with the condensation liquid separation device;
the circulating gas cooling device is connected with the circulating gas compressor;
the gas-liquid separation device is connected with the circulating gas cooling device;
the gas phase outlet and the liquid phase outlet of the gas-liquid separation device are respectively connected with the polymerization reaction device.
In the present invention, an ethylene flow regulator is preferably provided between the ethylene feed source line and the ethylene cooling means.
In the present invention, a solvent flow regulator is preferably provided between the solvent feed source line and the solvent cooling device.
In the present invention, the ethylene cooling apparatus preferably comprises a shell-and-tube cooler.
In the present invention, the outlet of the ethylene flow regulator is preferably connected to the tube side of the ethylene cooling apparatus.
In the present invention, the solvent cooling means preferably comprises a tube array cooler.
In the present invention, the outlet of the solvent flow regulator is preferably connected to the tube side of the solvent cooling device.
In the present invention, the condensing coil is preferably provided at the upper part of the condensate separating device.
In the present invention, the refrigerant line preferably opens into the condensing coil of the condensate distributor.
In the present invention, the height-to-diameter ratio of the condensation liquid separation apparatus is preferably (5 to 10): 1, more preferably (6 to 9): 1, more preferably (7 to 8): 1.
in the present invention, the circulating gas phase outlet of the polymerization reaction apparatus is preferably connected to the gas phase inlet at the lower part of the condensation liquid separation apparatus.
In the present invention, a flow rate adjusting device is preferably provided on the gas phase connection line between the condensation liquid separation device and the polymerization reaction device.
In the present invention, the liquid phase outlet of the condensation liquid separation apparatus is preferably connected to the polymerization reaction apparatus.
In the present invention, a liquid phase flow rate adjusting device is preferably provided on a liquid phase connecting line between the condensation liquid separation device and the polymerization reaction device.
In the present invention, the gas phase outlet of the recycle gas compressor is preferably connected to the tube side of the recycle gas cooling device.
In the present invention, a gas phase flow rate adjusting device is preferably provided on a pipe connecting the gas phase outlet of the gas-liquid separation device and the polymerization reaction device.
In the invention, a liquid phase flow regulating device is preferably arranged on a pipeline connected with the liquid phase outlet of the gas-liquid separation device and the polymerization reaction device.
In the present invention, the polymerization reaction apparatus is preferably provided with one or more of a heat-dissipating jacket, a stirring paddle, and a temperature sensor, more preferably provided with a heat-dissipating jacket, a stirring paddle, or a temperature sensor.
The invention is a complete and refined integral technical proposal, better improves the heat removal effect, further improves the long-period stable operation of the reaction system, and the heat removal process and the heat removal system for the reaction of preparing alpha-olefin by ethylene selective polymerization preferably comprise the following contents:
referring to fig. 1, fig. 1 is a schematic and simplified flow chart of a heat removal process for a reaction for producing alpha-olefins by selectively polymerizing ethylene. Wherein, 1-ethylene flow regulator, 2-solvent flow regulator, 3-ethylene cooler, 4-solvent cooler, 5, absorption tank, 6-mixed liquor buffer tank, 7-mixed liquor feed pump, 8-reaction kettle, 9-condensate liquid separating tank, 10-circulating gas compressor, 11-circulating gas cooler, 12-gas-liquid separating tank, 13-gas phase flow regulating valve, 14-liquid phase flow regulating valve, 15-liquid phase flow regulating valve, 16-flow regulating valve.
The heat removing method for the reaction of ethylene selective polymerization to prepare alpha-olefin comprises the aspects of raw material heat removing and reaction kettle gas phase heat removing;
in the aspect of heat removal of raw materials, an ethylene raw material enters an absorption tank (5) through an ethylene cooler (3), a butane solvent enters the absorption tank (5) through a solvent cooler (4) and is uniformly mixed with ethylene, then ethylene and butane mixed solution is introduced into a mixed solution buffer tank (6), and then the ethylene and butane mixed solution enters a reaction kettle (8) through a mixed solution feed pump (7).
The gas phase heat removal aspect of the reaction kettle comprises a reaction kettle (8) for carrying out ethylene selective oligomerization reaction, a condensation liquid separating tank (9) connected with the reaction kettle (8), a circulating gas compressor (10) connected with the condensation liquid separating tank, and a circulating gas cooler (11) connected with the circulating gas compressor, wherein the circulating gas enters a gas-liquid separation tank (12) after being cooled, and the gas phase and the liquid phase of the gas-liquid separation tank (12) are both communicated with the reaction kettle (8).
Further, the reaction heat removal method for preparing alpha-olefin by ethylene selective polymerization provided by the invention comprises the steps of raw material low-temperature feeding heat removal and reaction kettle gas phase external circulation heat removal, and a heat dissipation jacket, a temperature sensor and stirring paddles are arranged on the reaction kettle.
In the aspect of low-temperature feeding and heat removal of raw materials, the method comprises the steps of cooling an ethylene raw material to a certain temperature through an ethylene cooler, then, entering an absorption tank, cooling a butane solvent through a solvent cooler, then, entering the absorption tank, uniformly mixing with ethylene, then, introducing mixed solution of ethylene and butane into a mixed solution buffer tank, pressurizing the mixed solution of ethylene and butane in the mixed solution buffer tank through a mixed solution feeding pump, and then, entering a reaction kettle.
Specifically, the ethylene cooler (3) is a shell-and-tube cooler, the ethylene passes through the tube side of the ethylene cooler (3), the cooling medium is connected into the shell side of the ethylene cooler, and the temperature of the cooled ethylene is-20-5 ℃.
Specifically, the solvent cooler (4) is a shell-and-tube cooler, the solvent passes through the tube side of the solvent cooler (4), the cooling medium is connected into the shell side of the solvent cooler (4), and the temperature of the cooled solvent is-30-20 ℃.
Specifically, an ethylene flow controller (1) and a solvent flow controller (2) are respectively arranged between an ethylene and butane solvent feeding pipeline and an ethylene cooler (3) and a solvent cooler (4) and are used for controlling the proportion of ethylene and butane feeding and controlling the ethylene proportion in butane solvent to be 10-50%.
Further, an ethylene flow controller is arranged on the ethylene feeding pipeline, a solvent flow controller is arranged on the butane solvent feeding pipeline, the proportion of ethylene and butane entering the absorption tank can be regulated through the flow controller, and the ethylene proportion in the mixed solution buffer tank is controlled to be 10-50%. The low-temperature ethylene and the low-temperature solvent are mixed in advance, so that the polymerization reaction heat in part of the reaction kettle can be taken away, the mass transfer process of the ethylene in the reaction kettle solution is enhanced, and the stable operation of the polymerization reaction is facilitated.
The invention relates to a gas phase external circulation heat removal aspect of a reaction kettle, which comprises the reaction kettle for ethylene selective oligomerization, a condensation liquid separating tank connected with the reaction kettle, a circulating gas compressor connected with the condensation liquid separating tank, and a circulating gas cooler connected with the circulating gas compressor, wherein the circulating gas enters a gas-liquid separation tank after being cooled, and the gas phase and the liquid phase of the gas-liquid separation tank are both communicated with the reaction kettle.
The low-temperature ethylene and the low-temperature solvent are mixed in advance, so that the polymerization reaction heat in part of the reaction kettle can be taken away, the mass transfer process of the ethylene in the reaction kettle solution is enhanced, and the stable operation of the polymerization reaction is facilitated.
Specifically, a condensing coil is arranged at the upper part of the condensing liquid separating tank (9), a cooling medium is connected into the coil, and the height-diameter ratio of the condensing liquid separating tank is 5:1-10:1.
Furthermore, the invention uses the characteristic of low boiling point of butane and relatively light molecular weight, and particularly selects butane as a selective polymerization solvent. When ethylene enters the gas-phase external circulation system, a large amount of butane is entrained, after ethylene and butane in the reaction kettle enter the condensation liquid separation tank from a position below the middle part, butane is cooled and liquefied by the condensation coil pipe upwards, and then returns to the reaction kettle again from the bottom of the condensation liquid separation tank.
The gas phase of the condensing liquid separating tank enters the circulating gas compressor for pressurization, enters the circulating gas cooler for cooling, and then returns to the reaction kettle after passing through the gas-liquid separating tank.
Specifically, butane in a gas-phase ethylene entrainment part of the reaction kettle (8) enters a position of the middle part of the condensation liquid separation tank (9) which is lower, after being cooled by a condensing coil at the upper part of the condensation liquid separation tank (9), butane is liquefied and then returns to the reaction kettle (8), and a gas-phase part of the condensation liquid separation tank (9) enters a circulating gas compressor (10).
Specifically, a flow regulating valve (6) is arranged on a feed line from the gas phase of the reaction kettle (8) to the condensation liquid separating tank (9), and the opening of the flow regulating valve (16) is regulated according to the temperature condition in the reaction kettle, so that the circulation quantity of the gas phase external circulation in the reaction kettle (8) is controlled.
Specifically, a pipeline from the liquid phase of the gas-liquid separation tank (9) to the reaction kettle (8) is provided with a liquid phase flow regulating valve (15), and the liquid phase reflux quantity can be controlled according to the temperature of the reaction kettle.
Specifically, the circulating gas compressor (10) is connected with the tube side of the circulating gas cooler (11), the cooling medium is connected with the shell side of the circulating gas cooler (11), and the temperature of the cooling medium of the circulating gas cooler (11) is controlled to be-20 ℃.
Specifically, a gas phase pipeline from the gas-liquid separation tank (12) to the reaction kettle (8) is provided with a gas phase flow regulating valve (13), and a liquid phase pipeline is provided with a liquid phase flow regulating valve (14), so that the gas phase and liquid phase return kettle distribution ratio is regulated according to the temperature of the reaction kettle.
Specifically, the reaction kettle (8) is provided with a heat dissipation jacket, a stirring paddle and a temperature sensor.
The invention provides a heat removal method and a heat removal system for the reaction of preparing alpha-olefin by selectively polymerizing ethylene. The heat removing method of the invention is mainly divided into two parts, namely a raw material heat removing part: the raw material ethylene and the solvent are cooled by a cooler respectively, and the low-temperature raw material and the solvent are mixed uniformly and then enter a reaction kettle. The other part is a gas phase external circulation heat removal part of the reaction kettle: the reaction kettle is used for ethylene selective oligomerization reaction, a condensing liquid separating tank communicated with the reaction kettle, a circulating gas compressor connected with the condensing liquid separating tank, a cooler connected with the circulating gas compressor, and a gas-liquid separating tank connected with the cooler, wherein gas phase and liquid phase of the gas-liquid separating tank are both communicated with the reaction kettle. The process for preparing alpha-olefin (including 1-hexene, 1-octene, etc.) by ethylene selective polymerization is a hot spot studied in recent years and has the characteristic of remarkable economic benefit, the reaction of the process is a strong exothermic reaction, and the effective withdrawal of the reaction heat is the key point and the difficulty of the process. The heat removal method provided by the invention can quickly and efficiently remove the reaction heat in the reaction kettle of the polymerization reaction, thereby ensuring that the ethylene selective oligomerization reaction is stably carried out.
The invention provides a heat removal method and a heat removal system, which mainly comprise the steps that raw materials of ethylene and butane solvent enter respective coolers through a flow controller according to a certain proportion to cool, after the temperature is reduced to a certain temperature, the ethylene and butane are uniformly mixed at an absorption tank, ethylene butane mixed solution enters a mixed solution buffer tank to be buffered, the mixed solution is pressurized by a pump and enters a reaction kettle, low-temperature raw materials are in direct contact with reaction solution in the reaction kettle, part of reaction heat can be removed, and meanwhile, the ethylene in butane is gasified and rapidly removed. The butane solvent is carried in the gaseous phase ethylene from the top of the reaction kettle into a condensation liquid separating tank, most butane is cooled at a condensing coil pipe at the upper part of the condensation liquid separating tank and then returned to the reaction kettle from the bottom, partial butane carried in the gaseous phase ethylene comes out from the top of the condensation pipe, the gaseous phase ethylene enters a gas-liquid separation tank after being pressurized and cooled by a compressor and a cooler in sequence, uncondensed ethylene gas returns to the reaction kettle through the top of the condensation liquid separating tank, butane and partial liquefied ethylene return to the reaction kettle from the bottom of the condensation liquid separating tank, the proportion of gas phase and liquid phase in the condensation liquid separating tank can be regulated and controlled according to the temperature in the reaction kettle, the ethylene carries butane and returns to the reaction kettle after being cooled circularly, most of reaction heat in the reaction kettle can be withdrawn, and the reaction kettle is further provided with a cooling jacket and a stirring paddle, so that the effective withdrawal of ethylene selective polymerization reaction heat in the reaction kettle and stable operation of the device are further ensured. The heat removal process provided by the invention has the advantages that the process flow is simple, a plurality of heat removal modes coexist, butane is adopted as a reaction solvent, the property that butane is easy to vaporize and liquefy is utilized, the gas-phase external circulation heat removal capacity of the reaction kettle is increased, the work load of a circulating air compressor is reduced, and meanwhile, the heat removal modes of raw material low-temperature feeding and a heat dissipation jacket of the reaction kettle are adopted, so that the ethylene selective polymerization reaction heat can be rapidly and efficiently removed from the reaction kettle, and the polymerization reaction is ensured to run stably in the reaction kettle.
Experimental results show that the heat removal method and the heat removal system provided by the invention are adopted to run experiments on the reaction of preparing alpha-olefin by ethylene selective oligomerization of 400 tons/year, ethylene and solvent are mixed at low temperature and then fed, when the temperature of the mixed solution is controlled between minus 10 ℃ and 10 ℃, the proper gas phase external circulation quantity is controlled, so that the polymerization reaction heat in the reaction kettle can be completely removed, the temperature of the reaction kettle is ensured to be stable, and the long-period stable running of the device is ensured.
For further explanation of the present invention, a heat removal process and a heat removal system for a reaction for selectively polymerizing ethylene to produce α -olefins are described in detail below with reference to examples, but it should be understood that these examples are implemented on the premise of the technical scheme of the present invention, and detailed embodiments and specific operation procedures are given only for further explanation of the features and advantages of the present invention, and not limitation of the claims of the present invention, and the scope of protection of the present invention is not limited to the examples described below.
Example 1
As shown in figure 1, the method for removing heat in the reaction of preparing alpha-olefin by ethylene selective polymerization provided by the invention comprises the steps of cooling raw material ethylene to-10 ℃ through an ethylene cooler, then entering an absorption tank, cooling butane solvent to-10 ℃ through a solvent cooler, uniformly mixing the butane solvent with ethylene in the absorption tank, then passing through a mixed solution buffer tank, pressurizing mixed solution of ethylene and butane in the mixed solution buffer tank through a mixed solution feed pump, and then entering a reaction kettle. The butane solvent is returned to the reaction kettle from the bottom of the condensation liquid separating tank after cooling, the circulating gas compressor is connected from the top of the condensation liquid separating tank, and the circulating gas cooler is connected from the circulating gas compressor, and the circulating gas enters the gas-liquid separation tank after cooling, and the gas phase and the liquid phase of the gas-liquid separation tank are both communicated with the reaction kettle. And the jacket temperature of the reaction kettle is set between 30 and 50 ℃.
As is known from test run, when the polymerization reaction heat is withdrawn by adopting the combined action of the low-temperature feeding of raw materials, the jacket of the reaction kettle and the heat removal of gas phase external circulation, the ethylene selective polymerization reaction occurs in the reaction kettle under the action of a catalyst when the ethylene feeding amount is 50kg/h and the butane feeding amount is 70kg/h, the reaction temperature is controlled to be about 60 ℃, and the load of a circulating gas compressor is controlled to be about 350 kg/h. After running the apparatus for 500 hours, the catalyst activity was 2000Kg/gCr . h, the selectivity of the target product 1-hexene is 15%, the selectivity of 1-octene is 68%, and the solid is solidThe calculated value of the polymer PE is about 0.3%.
The device has stable temperature control, stable catalyst activity and product selectivity, and slow increase of stirring current of the reaction kettle.
Example 2
As shown in figure 1, the method for removing heat in the reaction of preparing alpha-olefin by ethylene selective polymerization provided by the invention has the advantages that raw materials of ethylene and solvent are directly and respectively fed into a reaction kettle at normal temperature without being cooled by a cooler. The butane solvent is returned to the reaction kettle from the bottom of the condensation liquid separating tank after cooling, the circulating gas compressor is connected from the top of the condensation liquid separating tank, and the circulating gas cooler is connected from the circulating gas compressor, and the circulating gas enters the gas-liquid separation tank after cooling, and the gas phase and the liquid phase of the gas-liquid separation tank are both communicated with the reaction kettle.
As is known from test run, when the polymerization reaction heat is withdrawn by adopting a reaction kettle jacket and gas phase external circulation heat removal, the ethylene feeding amount is 50kg/h, the butane feeding amount is 70kg/h, the ethylene selective polymerization reaction occurs in the reaction kettle under the action of a catalyst, the reaction temperature is controlled to be about 60 ℃, and the load of a circulating gas compressor is 500kg/h. After the device is operated for 500 hours, the catalyst activity is 1900Kg/gCr.h, the selectivity of the target product 1-hexene is 16%, the selectivity of 1-octene is 66%, and the calculated value of the solid polymer PE is about 0.35%.
It is found that the reduction of the heat removal of the low-temperature feed of the raw material results in a great increase in the operating load of the compressor, and the temperature control is slightly unstable, so that the overall catalyst activity, the product selectivity and the solid polymer production are not greatly affected.
Comparative example
As shown in figure 1, the provided method for removing heat in the reaction of preparing alpha-olefin by ethylene selective polymerization comprises the steps of cooling raw material ethylene to-10 ℃ through an ethylene cooler, then entering an absorption tank, cooling a solvent to-10 ℃ through a solvent cooler, uniformly mixing the solvent and ethylene in the absorption tank, then passing through a mixed solution buffer tank, pressurizing mixed solution of ethylene and butane in the mixed solution buffer tank through a mixed solution feed pump, and then entering a reaction kettle. The reaction kettle is internally provided with a conventional condensing coil, the reaction temperature is controlled by controlling the temperature of a cooling medium in the coil, and meanwhile, the reaction heat is withdrawn by adopting a jacket of the reaction kettle.
When the raw materials are fed at low temperature, the condensing coil of the reaction kettle and the jacket of the reaction kettle are jointly withdrawn from the polymerization reaction heat, the ethylene feeding amount is 50kg/h, the butane feeding amount is 70kg/h, the ethylene selective polymerization reaction is carried out in the reaction kettle under the action of a catalyst, and the reaction temperature is controlled to be about 60 ℃. After 100h of operation, the catalyst activity is 1100Kg/gCr.h, the target product 1-hexene selectivity is 13%, the 1-octene selectivity is 58%, and the calculated value of the solid polymer PE is about 1.0%.
Because the reaction heat is not withdrawn timely, an overtemperature event of the reaction kettle often occurs, when the temperature of the reaction kettle is overtemperature, the solid polymer is obviously increased, and the solid polymer is separated out on a condensing coil, so that the liquid phase space of the reaction kettle is greatly reduced, and the activity of the catalyst and the selectivity of the product are affected. As solid polymer is continuously accumulated in the reaction kettle, the stirring current is rapidly increased, and finally the stirring cannot rotate, so that the reaction is forced to be stopped, and the single longest operation time of the device is 120 hours.
According to the method for removing the ethylene selective polymerization reaction heat by utilizing the combination of the raw material low-temperature feeding and the gas-phase external circulation, disclosed by the invention, the ethylene and butane solvents are cooled and then uniformly mixed into the reaction kettle to react, a large amount of butane is carried in the gas-phase external circulation of the ethylene, the butane flows back to the reaction kettle to be cooled when encountering cold, and meanwhile, the rest gas phase sequentially returns to the reaction kettle through the circulating gas compressor, the circulating gas cooler and the gas-liquid separation tank to take away the polymerization reaction heat, so that a plurality of efficient heat removing modes coexist, and the aim of stably controlling the reaction temperature of the reaction kettle is fulfilled.
The foregoing has outlined, rather broadly, the principles and embodiments of the present invention by providing a heat removal process and heat removal system for the selective polymerization of ethylene to produce alpha-olefins, wherein specific examples are set forth herein to aid in the understanding of the process and its core concepts, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems, and performing any incorporated methods. It should be noted that it will be apparent to those skilled in the art that various modifications and adaptations of the invention can be made without departing from the principles of the invention and these modifications and adaptations are intended to be within the scope of the invention as defined in the following claims. The scope of the patent protection is defined by the claims and may include other embodiments that occur to those skilled in the art. Such other embodiments are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.
Claims (10)
1. The heat removing process for the reaction of preparing alpha-olefin by ethylene selective polymerization is characterized by comprising the steps of removing heat from raw materials and removing heat from a gas phase of a polymerization reaction device;
the heat removal of the raw materials comprises the following steps:
1) Cooling an ethylene raw material by an ethylene cooling device, and then entering an absorption device;
after being cooled by a solvent cooling device, the solvent is also sent into an absorption device and is uniformly mixed with ethylene to obtain a mixed solution;
2) Introducing the mixed solution obtained in the steps into a mixed solution buffer device, and then introducing the mixed solution into a polymerization reaction device;
the gas phase heat removal of the polymerization reaction device comprises the following steps:
and (3) carrying out external circulation on the gas phase of the polymerization reaction device, firstly sending the gas phase into a condensation liquid separation device for condensation liquid separation, then processing the liquid separated gas phase by a circulating gas compressor, then sending the gas phase into a circulating gas cooling device for cooling, then sending the gas phase into a gas-liquid separation device for gas-liquid separation, and finally respectively returning the gas phase and the liquid phase after gas-liquid separation to the polymerization reaction device.
2. The heat removal process of claim 1, wherein the α -olefin comprises one or more of 1-butene, 1-hexene, 1-octene, 1-decene, and 1-dodecene;
the solvent comprises butane;
the ethylene raw material is cooled by an ethylene cooling device, namely, the ethylene raw material is introduced into a tube side of the ethylene cooling device, and a cooling medium is introduced into a shell side of the ethylene cooling device;
the temperature of the ethylene raw material after passing through the ethylene cooling device is-20-5 ℃.
3. The heat removal process of claim 1, wherein the solvent is cooled by a solvent cooling device, specifically, the solvent is introduced into a tube side of the solvent cooling device, and the cooling medium is introduced into a shell side of the solvent cooling device;
the temperature of the solvent after passing through the solvent cooling device is-30-20 ℃;
the mass ratio of the ethylene to the solvent is (10-50): 100;
the gas phase comprises ethylene and butane.
4. The heat removal process according to claim 1, wherein the upper part of the condensation liquid separation device is provided with a condensation coil, and a cooling medium is introduced into the coil;
the gas phase is sent to the middle lower part of the condensation liquid separating device;
after the condensation and liquid separation, the liquefied liquid phase returns to the polymerization reaction device;
the liquid phase comprises butane;
the liquid phase reflux amount returned to the polymerization reaction apparatus is controlled based on the temperature of the polymerization reaction apparatus.
5. The heat removal process according to claim 1, wherein the volume ratio of the gas phase circulation amount per hour of the external circulation to the ethylene feed amount per hour of the polymerization reaction apparatus is (2 to 10): 1, a step of;
the gas phase is sent to a tube side of the circulating gas cooling device after being processed by a circulating gas compressor, and a cooling medium is introduced to a shell side of the circulating gas cooling device;
the temperature of the cooling medium is-20 ℃;
the ratio of the gas phase and the liquid phase after the gas-liquid separation returned to the polymerization reaction device is controlled based on the temperature of the polymerization reaction device;
the volume ratio of the gas phase and the liquid phase after gas-liquid separation returned to the polymerization reaction device is (2-10): 1.
6. the heat removal system for the reaction of preparing alpha-olefin by selectively polymerizing ethylene is characterized in that the heat removal device comprises a raw material heat removal system and a gas phase heat removal system of a polymerization reaction device;
the raw material heat removal system comprises:
an ethylene cooling unit connected to an ethylene feed source;
a solvent cooling device connected to a solvent feed source;
absorption means connected to said ethylene cooling means and said solvent cooling means;
a mixed liquid buffer device connected with the absorption device;
the mixed solution buffer device is connected with the polymerization reaction device;
the polymerization reaction device gas phase heat removal system comprises:
a polymerization reaction device;
the condensation liquid separation device is connected with the polymerization reaction device;
a recycle gas compressor connected with the condensation liquid separation device;
the circulating gas cooling device is connected with the circulating gas compressor;
the gas-liquid separation device is connected with the circulating gas cooling device;
the gas phase outlet and the liquid phase outlet of the gas-liquid separation device are respectively connected with the polymerization reaction device.
7. The heat removal system of claim 6, wherein an ethylene flow regulator is further disposed between the ethylene feed source line and the ethylene cooling apparatus;
a solvent flow regulator is also arranged between the solvent feed source pipeline and the solvent cooling device;
the ethylene cooling device comprises a shell and tube cooler;
and the outlet of the ethylene flow regulator is connected with the tube side of the ethylene cooling device.
8. The heat removal system of claim 6, wherein said solvent cooling means comprises a tube array cooler;
the outlet of the solvent flow regulator is connected with the tube side of the solvent cooling device;
the upper part of the condensation liquid separation device is provided with a condensation coil;
the cold medium pipeline is connected into a condensing coil of the condensing liquid-separating device;
the height-diameter ratio of the condensation liquid separating device is (5-10): 1.
9. the heat removal system of claim 6, wherein a circulating gas phase outlet of said polymerization reaction means is connected to a gas phase inlet at a lower middle portion of said condensation liquid separation means;
a gas phase connecting pipeline of the condensation liquid separation device and the polymerization reaction device is provided with a flow regulating device;
the liquid phase outlet of the condensation liquid separation device is connected with the polymerization reaction device;
and a liquid phase flow regulating device is arranged on a liquid phase connecting pipeline of the condensation liquid separating device and the polymerization reaction device.
10. The heat removal system of claim 6, wherein a gas phase outlet of said recycle gas compressor is connected to a tube side of said recycle gas cooling device;
a gas phase flow regulating device is arranged on a pipeline connected with the polymerization reaction device at a gas phase outlet of the gas-liquid separation device;
a liquid phase flow regulating device is arranged on a pipeline connected with the polymerization reaction device at a liquid phase outlet of the gas-liquid separation device;
one or more of a heat dissipation jacket, a stirring paddle and a temperature sensor are arranged on the polymerization reaction device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310182571.0A CN116143576A (en) | 2023-02-24 | 2023-02-24 | Heat removal method and heat removal system for reaction of preparing alpha-olefin by ethylene selective polymerization |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310182571.0A CN116143576A (en) | 2023-02-24 | 2023-02-24 | Heat removal method and heat removal system for reaction of preparing alpha-olefin by ethylene selective polymerization |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116143576A true CN116143576A (en) | 2023-05-23 |
Family
ID=86359919
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310182571.0A Pending CN116143576A (en) | 2023-02-24 | 2023-02-24 | Heat removal method and heat removal system for reaction of preparing alpha-olefin by ethylene selective polymerization |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116143576A (en) |
-
2023
- 2023-02-24 CN CN202310182571.0A patent/CN116143576A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US8013201B2 (en) | High energy reduction in a propane dehydrogenation unit by utilizing a high pressure product splitter column | |
| EP0099701B1 (en) | Process and apparatus for converting olefins into gasoline and distillate | |
| US10556845B2 (en) | System and producing method for preparing alkylated oil by using sulfuric acid as catalyst | |
| CN113233951B (en) | Production device and production process for producing linear alpha-olefin by selective oligomerization of ethylene | |
| US20120330078A1 (en) | PROCESS FOR PREPARING LINEAR alpha-OLEFINS | |
| CN113511949A (en) | Production process for co-producing 1-hexene and 1-octene through ethylene selective oligomerization | |
| CN205730772U (en) | The system of hydrocarbon mixture is reclaimed from polyolefin row's torch gas | |
| JP2001506977A (en) | Method and reactor for epoxidation with energy recovery | |
| US6927260B2 (en) | Optimization of heat removal in a gas-phase fluidized-bed process | |
| CN114957530A (en) | Solution polymerization method of ethylene and alpha-olefin | |
| CN208883740U (en) | A kind of expense drags synthesis tail gas deep cooling recyclable device | |
| CN101092325A (en) | Method for preparing propylene by catalytic cracking olefin of containing carbon | |
| CN116143576A (en) | Heat removal method and heat removal system for reaction of preparing alpha-olefin by ethylene selective polymerization | |
| CN112830861B (en) | Device and method for producing n-butane | |
| CN110804112A (en) | Reactant recycling system and chemical reaction system | |
| CN111747814B (en) | Method for coupling deethanization process and propane dehydrogenation process before hydrocarbon steam cracking | |
| US5962761A (en) | Process for linear alpha-olefin production | |
| CN114210287A (en) | Device and process for producing 1-octene through ethylene selective oligomerization | |
| JP7250399B2 (en) | Alpha-olefin manufacturing method and alpha-olefin manufacturing apparatus | |
| WO2014202715A1 (en) | Process for the production of epdm elastomers in solution and polymerisation reactor for use in said process. | |
| CN111848327B (en) | Method for coupling depropanization process and propane dehydrogenation process before hydrocarbon steam cracking | |
| CN107285981B (en) | Demethanizer heat exchange system and heat exchange method | |
| JP7195688B2 (en) | Oligomer production method and oligomer production apparatus | |
| JP3344594B2 (en) | Reaction method | |
| CN111992174A (en) | Alkylation reaction system and matched alkylation reaction process method thereof |
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 | ||
| TA01 | Transfer of patent application right | ||
| TA01 | Transfer of patent application right |
Effective date of registration: 20231221 Address after: Room G297, Office Building 2, Bonded Port Area, Xinyingwan District, Yangpu Economic Development Zone, Haikou City, Hainan Province, 578001 Applicant after: Hainan Beiouyi Technology Co.,Ltd. Address before: 256500 Jingbo Industrial Park, Boxing Economic Development Zone, Binzhou, Shandong, China Applicant before: SHANDONG CHAMBROAD PETROCHEMICALS Co.,Ltd. |