CN110183301B - Methanol-to-propylene system and method for starting and feeding by using same - Google Patents
Methanol-to-propylene system and method for starting and feeding by using same Download PDFInfo
- Publication number
- CN110183301B CN110183301B CN201910468188.5A CN201910468188A CN110183301B CN 110183301 B CN110183301 B CN 110183301B CN 201910468188 A CN201910468188 A CN 201910468188A CN 110183301 B CN110183301 B CN 110183301B
- Authority
- CN
- China
- Prior art keywords
- reactor
- product stream
- methanol
- line
- temperature
- 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
- 238000000034 method Methods 0.000 title claims abstract description 57
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 claims abstract description 321
- 239000003054 catalyst Substances 0.000 claims abstract description 100
- 239000004215 Carbon black (E152) Substances 0.000 claims abstract description 88
- 229930195733 hydrocarbon Natural products 0.000 claims abstract description 88
- 150000002430 hydrocarbons Chemical class 0.000 claims abstract description 88
- LCGLNKUTAGEVQW-UHFFFAOYSA-N Dimethyl ether Chemical compound COC LCGLNKUTAGEVQW-UHFFFAOYSA-N 0.000 claims abstract description 68
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 62
- 238000010438 heat treatment Methods 0.000 claims abstract description 48
- QQONPFPTGQHPMA-UHFFFAOYSA-N propylene Natural products CC=C QQONPFPTGQHPMA-UHFFFAOYSA-N 0.000 claims abstract description 48
- 125000004805 propylene group Chemical group [H]C([H])([H])C([H])([*:1])C([H])([H])[*:2] 0.000 claims abstract description 48
- 238000006243 chemical reaction Methods 0.000 claims abstract description 47
- 239000000463 material Substances 0.000 claims abstract description 42
- 230000008569 process Effects 0.000 claims abstract description 33
- 238000003860 storage Methods 0.000 claims abstract description 14
- 238000007670 refining Methods 0.000 claims abstract description 8
- 238000005498 polishing Methods 0.000 claims description 14
- 238000000926 separation method Methods 0.000 claims description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 8
- 229910052757 nitrogen Inorganic materials 0.000 claims description 4
- 238000010926 purge Methods 0.000 claims description 4
- 238000001816 cooling Methods 0.000 claims description 3
- 239000000203 mixture Substances 0.000 claims description 2
- 238000010792 warming Methods 0.000 claims description 2
- 230000002194 synthesizing effect Effects 0.000 abstract description 8
- 238000004904 shortening Methods 0.000 abstract description 3
- 239000002994 raw material Substances 0.000 description 21
- 239000002699 waste material Substances 0.000 description 14
- 239000007789 gas Substances 0.000 description 7
- 230000018044 dehydration Effects 0.000 description 5
- 238000006297 dehydration reaction Methods 0.000 description 5
- 238000012840 feeding operation Methods 0.000 description 5
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000005265 energy consumption Methods 0.000 description 4
- 239000012530 fluid Substances 0.000 description 4
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 3
- 150000001336 alkenes Chemical class 0.000 description 3
- 229910052799 carbon Inorganic materials 0.000 description 3
- 239000012159 carrier gas Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- JRZJOMJEPLMPRA-UHFFFAOYSA-N olefin Natural products CCCCCCCC=C JRZJOMJEPLMPRA-UHFFFAOYSA-N 0.000 description 3
- 239000011148 porous material Substances 0.000 description 3
- 230000001105 regulatory effect Effects 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 230000008901 benefit Effects 0.000 description 2
- 238000004523 catalytic cracking Methods 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
- 239000003208 petroleum Substances 0.000 description 2
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 239000003245 coal Substances 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 238000005336 cracking Methods 0.000 description 1
- 230000003111 delayed effect Effects 0.000 description 1
- 230000008676 import Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000003345 natural gas Substances 0.000 description 1
- 239000011368 organic material Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
Images
Classifications
-
- 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
- B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
- B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
- B01J8/0242—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid flow within the bed being predominantly vertical
-
- 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
- B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
- B01J8/02—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds
- B01J8/04—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds
- B01J8/0446—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes with stationary particles, e.g. in fixed beds the fluid passing successively through two or more beds the flow within the beds being predominantly vertical
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C1/00—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon
- C07C1/20—Preparation of hydrocarbons from one or more compounds, none of them being a hydrocarbon starting from organic compounds containing only oxygen atoms as heteroatoms
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C41/00—Preparation of ethers; Preparation of compounds having groups, groups or groups
- C07C41/01—Preparation of ethers
- C07C41/09—Preparation of ethers by dehydration of compounds containing hydroxy groups
Abstract
The invention provides a methanol-to-propylene system and a method for starting and feeding materials by using the same, wherein the methanol-to-propylene system comprises a first reactor, a second reactor and a third reactor, wherein the first reactor is used for carrying out a reaction of synthesizing dimethyl ether from methanol to obtain a first product stream; the second reactor is used for performing the reaction of producing the propylene from the first product flow to obtain a second product flow; a first steam line for providing steam to the first reactor; heating means for heating a portion of the first product stream and the recycle hydrocarbon product stream to elevated temperatures; first and second side-line conduits for separately feeding portions of the first product stream and process water to the second to last catalyst beds; a refining unit for separating the second product stream to yield a recycle hydrocarbon product stream comprising C2, C4, C5, and C6 components; a recycle hydrocarbon storage tank for providing a recycle hydrocarbon product stream to the heating device. The system and the method for preparing propylene from methanol can control and even prevent temperature runaway conditions in the first reactor and the second reactor, thereby shortening the starting and feeding time.
Description
Technical Field
The invention belongs to the field of methanol to propylene, and particularly relates to a methanol to propylene system and a method for starting and feeding by using the same.
Background
Propylene is one of the most important chemical raw materials, and is mainly derived from petroleum routes such as FCC (catalytic cracking), naphtha cracking and the like at present. In recent years, the demand for propylene in China has increased sharply, but the petroleum yield in China is far from meeting the market demand, and the import rate is over 50%, under such a situation, the diversification of propylene production raw materials becomes a major problem related to the adjustment of national energy structure. The technology of synthesizing gas-phase methanol from natural gas and coal is mature, a good foundation is laid for the development of a process for preparing olefin from methanol, the process for preparing propylene from methanol becomes another important stable source after petrochemical industry, and the catalyst for preparing olefin from methanol is the core of the process technology.
The technology for preparing propylene from methanol is most representative of a fixed bed MTP (methanol to propylene) process successfully developed by Lurgi company in 20 th century at the end of 90 s, a reaction unit of the process is provided with two reactors of DME (dimethyl ether prepared from methanol) and MTP (propylene prepared from methanol), methanol raw materials enter the DME reactor from the top after being preheated, and methanol steam generates DME (dimethyl ether) under the action of an alumina-based catalyst (DME-1). A part of DME product is preheated and then sent into the bed layer of the MTP reactor from the side, and in addition, the DME product is mixed with C2-C6 circulating hydrocarbon from a refining unit and part of circulating water vapor, and then the mixture is heated by a heating furnace and then enters the MTP reactor.
The overtemperature condition of the reactor often appears in the feeding and commissioning process of the methanol-to-propylene device, and the runaway condition also appears when the overtemperature condition is serious, so that the temperature of a catalyst bed layer in the reactor is quickly raised and seriously deviates from a design value, and great harm is caused to reaction and equipment. In order to reduce the influence of over-temperature and temperature runaway on the catalyst and the components in the reactor, long time is needed to be spent, the feeding operation is carried out under a mild control condition, the starting feeding time of the reaction system is at least 10-12 hours, and the materials generated in the process need to be treated by a torch, so that the material consumption and the energy consumption of the MTP device are greatly increased, and huge economic loss is caused.
Disclosure of Invention
The first purpose of the invention is to provide a methanol-to-propylene system, which has a simple flow, and can prevent the influence of the over-temperature condition of a reactor on the feeding duration in the rapid start-up feeding process, thereby shortening the start-up feeding period and reducing the material consumption and energy consumption in the start-up feeding process.
The second purpose of the invention is to provide a method for starting and feeding by using the methanol to propylene system, which is simple and can prevent the influence of the over-temperature condition of the reactor on the feeding time in the process of quick starting and feeding, thereby shortening the starting and feeding period and reducing the material consumption and energy consumption in the process of starting and feeding.
In order to achieve the first purpose of the invention, the following technical scheme is adopted:
a methanol-to-propylene system, comprising:
a first reactor for carrying out a methanol to dimethyl ether reaction to obtain a first product stream; the first product stream comprises dimethyl ether, water, and unreacted methanol; the first product stream is output via a first product stream line; the first product stream lines include a flare line, a first line and a second line for outputting the first product streams from the first reactor separately, and the flare line for outputting a portion of the first product stream from the first reactor to a flare system;
a second reactor for performing the reaction of the first product stream to produce propylene to obtain a second product stream; and a plurality of catalyst beds are arranged in the second reactor along the longitudinal direction;
a first steam line for providing steam to the first reactor;
heating means for heating the first product stream from the first line and the recycle hydrocarbon product stream from the recycle hydrocarbon product stream line to an elevated temperature for feeding to the first catalyst bed as a top feed to the second reactor;
A first side line conduit for receiving the first product stream from the second line and passing the received material to the second to last catalyst beds respectively;
a second side line conduit for delivering water to the second to last catalyst beds, respectively;
a polishing unit for separating the second product stream to yield a recycle hydrocarbon product stream comprising C2, C4, C5, and C6 components, the recycle hydrocarbon product stream being fed at least in part through the recycle hydrocarbon product stream line to the heating unit;
a recycle hydrocarbon storage tank 18 for providing a recycle hydrocarbon product stream to the heating device.
Preferably, the methanol to propylene system further comprises a second steam line for supplying steam to the second reactor from the top; the heating device is used for heating the first product stream from the first pipeline, the water vapor from the second water vapor pipeline and the circulating hydrocarbon product stream from the circulating hydrocarbon product stream pipeline to raise the temperature so as to send the first product stream and the water vapor to the first catalyst bed layer as the top feeding of the second reactor.
Preferably, the methanol to propylene system further comprises a first heat exchanger for warming the water vapor from the first water vapor line to be fed as a top feed of the first reactor together with methanol from the methanol line;
Preferably, the first product stream line further comprises a third line for outputting a portion of the first product stream from the first reactor; the methanol-to-propylene system further comprises a second heat exchanger, and the second heat exchanger is used for cooling the first product stream from the third pipeline and then sending the cooled first product stream into the first side pipeline.
Preferably, the methanol to propylene system further comprises a third steam line for feeding steam into the first side line.
In order to achieve the second object of the present invention, the present invention provides a method for starting up a car and feeding materials by using the above methanol to propylene system, the method comprising the following steps:
(1) purging and heating the methanol-to-propylene system to 180-220 ℃ sequentially by using nitrogen, then supplying water vapor to the first reactor by using the first water vapor pipeline to heat the catalyst bed layer in the first reactor to 255-260 ℃, then performing a methanol-to-dimethyl ether reaction in the first reactor by using input methanol to obtain a first product stream, and outputting the first product stream from the first reactor to a flare system by using a flare pipeline;
(2) when the temperature difference between the inlet and outlet of the first reactor is not more than +/-5 ℃ and the temperature of the catalyst bed layer reaches 265- -1(at this time, after the pressure in the first reactor reaches 1.0-1.45Mpa), outputting the first product stream from the first reactor to the heating device through the first pipeline, raising the temperature to 460 ℃ and then sending the first product stream to the first catalyst bed layer as the top feed of the second reactor, and performing a methanol-to-propylene reaction in the second reactor (2) to obtain a second product stream; the second product stream is then passed to the polishing unit;
(3) when the outlet temperature of the first reactor reaches 325-; then continuing to convey the second product stream to the polishing unit for separation to yield a recycle hydrocarbon product stream comprising C2, C4, C5, and C6 components;
then the recycle hydrocarbon product stream from the refining unit is also input into the heating device, and after the temperature of the recycle hydrocarbon product stream is raised to 460 ℃ together with the first product stream output by the first pipeline and the recycle hydrocarbon product stream from the recycle hydrocarbon storage tank 18, the recycle hydrocarbon product stream is continuously sent to the first catalyst bed as the top feed of the second reactor to continuously generate the reaction of preparing propylene from methanol to obtain a second product stream; to the extent that the recycle hydrocarbon product stream from the polishing unit can continue to meet the feed requirements of the second reactor, the supply of recycle hydrocarbon product stream from recycle hydrocarbon storage tank 18 to the heating means is stopped;
(4) And when the outlet temperature of the first reactor reaches 360-375 ℃, receiving the first product flow output by the second pipeline by using the first side pipeline, receiving water by using the second side pipeline, respectively sending the received materials to the second to last catalyst bed layers as side feeding of the second reactor to continue the reaction of preparing propylene from methanol to obtain a second product flow, and adjusting the temperature of the catalyst bed layer of the second reactor to 480-490 ℃ and maintaining the temperature to complete the process of starting and feeding.
It is understood that the methanol fed into the first reactor is preheated at a temperature of 250-280 ℃.
Preferably, the feeding space velocity of the methanol is 0.5-0.6h-1。
Preferably, in the step (1), the temperature of the water vapor is raised to 200-220 ℃ by using the first heat exchanger before being supplied to the first reactor.
Preferably, in the step (3), the top feed of the second reactor further comprises steam, and the steam is conveyed to the heating device through the second steam line, and is heated together with the first product stream output through the first line and the recycled hydrocarbon product stream from the recycled hydrocarbon product stream line to the temperature of 420-460 ℃, and then is sent to the first catalyst bed as the top feed of the second reactor.
Preferably, in the step (3), the flow rate of the water vapor from the second water vapor pipeline is Q1, the flow rate of the circulating hydrocarbon product stream from the circulating hydrocarbon product stream pipeline is Q2, and the flow rate of the methanol from the methanol pipeline is Q3, then the temperature of the catalyst bed layer which is fed from the top of the second reactor to the second reactor in the step (3) reaches 480-.
Preferably, in the step (4), when the outlet temperature of the first reactor reaches 360-.
Preferably, in the step (4), when the outlet temperature of the first reactor reaches 360-375 ℃, the third steam pipeline is also used for providing steam to the second reactor from the side line; and the water vapor from the third water vapor pipeline and the mixed material of the material from the second heat exchanger and the first product stream from the second pipeline are respectively sent to the second to the last catalyst beds by using the first side pipeline so as to adjust the feeding temperature of the second to the last catalyst beds.
The invention has the beneficial effects that:
the invention relates to a methanol-to-propylene system and a method for starting and feeding materials by using the same,
the first steam pipe line is arranged to provide steam to the first reactor, so that on one hand, a catalyst bed layer in the first reactor 1 is heated to raise the temperature, the catalyst bed layer in the first reactor 1 reaches the reaction temperature of the reaction for synthesizing dimethyl ether by methanol gas phase dehydration as soon as possible, the feeding time is shortened, on the other hand, the heat of adsorption of the steam in a catalyst pore passage and the heat of reaction for synthesizing dimethyl ether by methanol gas phase dehydration are sequentially and respectively released, and temperature runaway caused by superposition of the two kinds of heat is prevented;
the second steam pipeline is arranged to provide steam to the second reactor from the top, and on one hand, the steam can be used as a carrier to play a role of a carrier gas, so that the partial pressure of raw material methanol/DME is reduced, and the reaction selectivity and the yield of propylene products are improved; on the other hand, the method can dilute the raw material methanol, so that less raw material methanol is contacted with the catalyst in the second reactor to delay the generation of carbon on the surface of the catalyst;
by arranging a second heat exchanger such that the side feed to the second reactor comprises at least two parts: part of the first product flow directly coming from the first reactor and the first product flow cooled by the second heat exchanger, so that the catalyst bed temperature of the second reactor is further regulated and controlled through the respective feeding amounts of the two parts of materials to prevent temperature runaway;
Providing steam to the second reactor from a side stream by providing a third steam line such that the side stream feed to the second reactor comprises at least three portions: part of the first product flow directly coming from the first reactor, the first product flow cooled by the second heat exchanger and the steam coming from the third steam pipeline, so that the catalyst bed layer temperature of the second reactor is further regulated and controlled by the respective feeding amounts of the three parts of materials to prevent temperature runaway;
through the control of the flying temperature condition in the starting and feeding process, the feeding speed is improved, the starting and feeding time is greatly shortened from 10-12 hours to 2 hours, and the material waste and the energy waste are reduced; the start-up feeding time is shortened, the consumption of methanol raw materials of a torch system is reduced, the yield of products (including propylene, LPG and mixed aromatic hydrocarbon) is increased, and the two aspects are added, so that the improvement and efficiency increase of 117 ten thousand yuan plus 34.81 ten thousand yuan (151.81 ten thousand yuan) can be realized by one-time start-up feeding.
Drawings
Fig. 1 is a flow chart of a methanol-to-propylene system according to an embodiment of the present invention.
Detailed Description
The technical solution and effects of the present invention will be further described below by way of specific embodiments. The following embodiments are merely illustrative of the present invention, and the present invention is not limited to the following embodiments or examples. Simple modifications of the invention applying the inventive concept are within the scope of the invention as claimed.
As shown in fig. 1, the methanol-to-propylene system of the present invention includes:
a first reactor 1 for carrying out a methanol to dimethyl ether reaction to obtain a first product stream; the first product stream comprises dimethyl ether, water, and unreacted methanol; the first product stream is output via a first product stream line; the first product stream lines include a flare line 6, a first line 15 and a second line 16 for outputting the first product streams from the first reactor 1, respectively, and the flare line 6 for outputting a portion of the first product stream from the first reactor 1 to a flare system;
a second reactor 2 for performing the reaction of the first product stream to produce propylene to obtain a second product stream; and a plurality of catalyst beds are arranged in the second reactor 2 along the longitudinal direction;
a first steam line 3 for supplying steam to the first reactor 1;
Heating means 7 for heating the first product stream from the first line 15 and the recycle hydrocarbon product stream from the recycle hydrocarbon product stream line to a temperature such that they are fed to the first catalyst bed as the top feed to the second reactor 2;
a first side line 9 for receiving a first product stream from the second line 16 and sending the received materials to the second to last catalyst beds, respectively;
a second side line conduit 10 for sending water to the second to last catalyst beds, respectively;
a polishing unit 11 for separating the second product stream to obtain a recycle hydrocarbon product stream comprising C2, C4, C5 and C6 components, the recycle hydrocarbon product stream being fed at least in part through the recycle hydrocarbon product stream line 8 to the heating unit 7;
a recycle hydrocarbon storage tank 18 for providing a recycle hydrocarbon product stream to the heating means 7.
It will be appreciated by those skilled in the art that the first reactor 1 is a DME reactor (i.e. a methanol to dimethyl ether reactor) and the second reactor 2 is an MTP reactor (i.e. a methanol to propylene reactor).
It will be understood by those skilled in the art that in the present invention, the water may be process water, and the sources of the process water include water produced when methanol is reacted to produce dimethyl ether, water produced when methanol/dimethyl ether is reacted to produce olefin, and water produced when water vapor introduced into the methanol to propylene system is condensed, and the sum of these three parts is called process water, and the process water is mainly used for distinguishing from circulating water used in plants. The process steam is steam generated by using process water as a raw material and heating the raw material by a reboiler at the bottom of a process steam tower. The process steam is mainly to be distinguished from low-pressure, high-pressure, medium-pressure and the like steam. Steam in this application refers to the process steam described above.
Sources of the recycled hydrocarbon product stream include two: one source is the tank farm, i.e., the separation of the second product stream from the second reactor from the previous start-up charge; the second source is obtained by separating a second product flow of the second reactor during the starting and feeding of the vehicle; the second product stream from the second reactor 2 is supplied to the circulating hydrocarbon when the whole system is in steady operation, and the steady operation of the whole system can be ensured without introducing the circulating hydrocarbon product stream from the tank field.
When the refining unit 11 separates the second product stream, the second product stream is cooled and compressed, and then is subjected to gas-liquid separation; the separated liquid hydrocarbon (C4 and above components) enters a debutanizer to separate residual low-boiling components C4, DME and a small amount of C3 components, and enters a debutanizer from the bottom of the debutanizer, and C5 and C6 components are obtained at the top of the debutanizer; the separated gas hydrocarbon (C3 and the following components) and the overhead product C3 of the debutanizer and DME components enter a depropanizer together for separation, C2 and C3 components are separated from the tower top, and C4 components are obtained from the tower bottom; the C2 and C3 components at the top of the depropanizing tower enter a deethanizing tower for further separation to obtain a C2 component at the top of the depropanizing tower and a C3 component at the bottom of the depropanizing tower; thereby producing a recycle hydrocarbon product stream comprising C2, C4, C5, and C6 components.
The system for preparing the propylene from the methanol is provided with the first steam pipeline 3 to provide steam for the first reactor 1, so that the catalyst bed layer in the first reactor 1 is heated to raise the temperature on one hand, the catalyst bed layer in the first reactor 1 can reach the reaction temperature of the reaction for synthesizing the dimethyl ether by dehydrating the methanol in a gas phase as soon as possible, and the feeding time is shortened; on the other hand, the heat of adsorption of the water vapor in the catalyst pore passage and the heat of reaction for synthesizing dimethyl ether by gas phase dehydration of methanol can be sequentially and respectively released, so that the condition that the temperature runaway of the first reactor 1 is caused by the superposition of the two types of heat in the first reactor 1 is prevented. Because the temperature runaway has great influence on the catalyst and the reactor internal components, if the first steam pipeline 3 is not arranged, the long time is needed to be spent, and the feeding operation is carried out under the mild control condition, so that the influence of the temperature runaway on the catalyst and the reactor internal components is reduced; the temperature runaway condition of the first reactor 1 can be effectively controlled and even prevented by arranging the first steam pipeline 3, so that the temperature runaway condition in the first reactor 1 can be controlled in the starting and feeding processes, the feeding speed is improved, the starting and feeding time is shortened, and the material waste and the energy waste are reduced.
In one embodiment, the methanol to propylene system further comprises a second steam line 12 for supplying steam from the top to the second reactor 2; the heating device 7 is used for heating the first product stream from the first pipeline 15, the water vapor from the second water vapor pipeline 12 and the recycle hydrocarbon product stream from the recycle hydrocarbon product stream pipeline 8 to raise the temperature, so that the first product stream is fed to the first catalyst bed layer as the top feed of the second reactor 2.
The second steam pipeline 12 is arranged to provide steam to the second reactor 2 from the top, and on one hand, the steam can be used as a carrier to play a role of a carrier gas, so that the partial pressure of raw material methanol/DME is reduced, and the reaction selectivity and the yield of propylene products are improved; on the other hand, the method can dilute the raw material methanol, so that less raw material methanol is contacted with the catalyst in the second reactor 2 to delay the generation of carbon on the surface of the catalyst.
In one embodiment, the methanol to propylene system further comprises a first heat exchanger 4 for heating the water vapor from the first water vapor line 3 to feed it together with the methanol from the methanol line 5 as the top of the first reactor 1, so that the bed temperature of the first reactor 1 reaches the temperature required for the reaction as soon as possible to shorten the feeding time.
In one embodiment, the first product stream line further comprises a third line 17 for outputting a portion of the first product stream from the first reactor 1; the methanol-to-propylene system further comprises a second heat exchanger 13 for cooling the first product stream from the third pipeline 17 and feeding the cooled first product stream into the first side pipeline 9.
The second heat exchanger 13 is arranged so that the side feed to the second reactor 2 comprises at least two parts: the first product flow directly coming from the first reactor 1 and the first product flow cooled by the second heat exchanger 13 further regulate and control the catalyst bed temperature of the second reactor 2 through the respective feeding amounts of the two parts of materials so as to prevent the temperature runaway condition in the second reactor 2. Because the temperature runaway has great influence on the catalyst and the reactor internal components, if the second heat exchanger 13 is not arranged, a long time is needed to be spent, and the feeding operation is carried out under a mild control condition, so that the influence of the temperature runaway on the catalyst and the reactor internal components is reduced; the second heat exchanger 13 can conveniently control the temperature runaway condition in the second reactor 2, even prevent the temperature runaway condition in the second reactor 2, so that the temperature runaway condition in the second reactor 2 can be controlled in the starting and feeding processes, the feeding speed is further improved, the starting and feeding time is further shortened, and the material waste and the energy waste are reduced.
In one embodiment, the methanol to propylene system further comprises a third steam line 14 for feeding steam into the first side line conduit 9.
The third steam line 14 is arranged such that the side feed to the second reactor 2 comprises at least three portions: a part of the first product flow directly coming from the first reactor 1, the first product flow cooled by the second heat exchanger 13 and the steam coming from the third steam pipeline 14, so that the catalyst bed temperature of the second reactor 2 is further regulated and controlled by the respective feeding amounts of the three parts of materials to prevent the temperature runaway condition in the second reactor 2. Because the temperature runaway has great influence on the catalyst and the reactor internal components, if the second heat exchanger 13 is not arranged, the feeding operation needs to be carried out for a long time under a mild control condition, so that the influence of the temperature runaway on the catalyst and the reactor internal components is reduced; the third steam pipeline 14 can effectively control the temperature runaway condition in the second reactor 2, even prevent the temperature runaway condition in the second reactor 2, so that the temperature runaway condition in the second reactor 2 can be further controlled in the starting and feeding process, the feeding speed is further improved, the starting and feeding time is further shortened, and the material waste and the energy waste are reduced.
It will be understood by those skilled in the art that each pipeline and conduit is provided with a switch valve and/or a flow valve to control whether the material flow on the corresponding pipeline or conduit is transmitted or not, or even to control the proportion of the material flow on the corresponding pipeline or conduit through the opening degree of the switch valve or flow valve, so as to adjust the material temperature entering each catalyst bed layer in the reactor, thereby preventing the temperature runaway condition in the reactor. For example, the feed amount of three parts of side feeds (the part of the first product stream directly from the first reactor 1, the first product stream after being cooled by the second heat exchanger 13 and the steam from the third steam line 14) of the second reactor 2 is respectively adjusted by an on-off valve and/or a flow valve to adjust the material temperature finally fed into the second to last catalyst beds of the second reactor 2 through the side feed, so as to adjust the temperature of the second to last catalyst beds of the second reactor 2, thereby preventing the temperature runaway condition in the second reactor 2.
The invention also provides a method for starting the vehicle and feeding materials by using the system for preparing propylene from methanol, which comprises the following steps:
(1) purging and heating the methanol to propylene system to 180-220 ℃ (preferably 190-210 ℃, such as 195 ℃, 200 ℃ and 205 ℃) in sequence by using nitrogen, then supplying water vapor to the first reactor 1 by using the first water vapor pipeline 3 to heat the catalyst bed layer in the first reactor 1 to 255-260 ℃ (such as 256 ℃, 257 ℃ and 258 ℃), generating a methanol to dimethyl ether reaction in the first reactor 1 by using input methanol to obtain a first product stream, and outputting the first product stream from the first reactor 1 to a flare system by using a flare pipeline 6;
(2) When the temperature difference between the inlet and outlet of the first reactor 1 is not more than +/-5 ℃ and the temperature of the catalyst bed layer reaches 265-320 ℃ (preferably 275-305 ℃, such as 282 ℃, 290 ℃ and 300 ℃), the flare pipeline 6 is closed, and the feed space velocity of the methanol is raised to 0.65-0.75h-1(preferably 0.68-0.72 h)-1For example 0.7h-1) (at this time, after the pressure in the first reactor 1 reaches 1.0-1.45Mpa), the first product from the first reactor 1 is output to the heating device 7 through the first pipeline 15, heated to 420-; then the second product stream is fed to the refining unit 11 (in the stage after the closing of the flare line 6 and before the outlet temperature of the first reactor 1 reaches 325- For separation, however, when the outlet temperature of the first reactor 1 reaches 325-;
(3) when the outlet temperature of the first reactor 1 reaches 325-; the second product stream is then passed on to the polishing unit 11 for separation to yield a recycle hydrocarbon product stream comprising C2, C4, C5 and C6 components;
then the recycle hydrocarbon product stream from the refining unit 11 is also fed into the heating device 7 to be heated up to 420-460 ℃ (preferably 430-450 ℃, such as 440 ℃) together with the first product stream output through the first pipeline 15 and the recycle hydrocarbon product stream from the recycle hydrocarbon storage tank 18, and then is continuously fed into the first catalyst bed as the top feed of the second reactor 2 to continuously perform the reaction of methanol to propylene to obtain a second product stream; the supply of the recycle hydrocarbon product stream from recycle hydrocarbon storage tank 18 to heating means 7 is stopped until the feed demand to the second reactor 2 is continuously met (i.e. the recycle hydrocarbon product stream from the polishing unit 11 can be stably supplied to the second reactor 2 in sufficient quantity, or in addition to, an excess of recycle hydrocarbon product stream, which excess can be sent to a tank farm for storage for the next start-up charge, or for another use);
(4) When the outlet temperature of the first reactor 1 reaches 360-.
When the temperature of the catalyst bed layer of the first reactor 1 reaches 255-260 ℃, the catalyst has higher activity, and the initial top feeding of the first reactor 1 helps to improve the methanol conversion rate and DME selectivity of the reaction for preparing dimethyl ether from methanol.
When the first reactor 1 is fed, the reaction raw materials penetrate through the catalyst from top to bottom, and because the reaction is an exothermic reaction, the hotspot temperature (i.e. the highest temperature point) of the catalyst continuously moves downwards along with the extension of the feeding time, and the inlet and outlet temperatures of the first reactor 1 show the following trends: a first stage, the inlet temperature is higher than the outlet temperature; in the second stage, the inlet temperature is equivalent to the outlet temperature; and in the third stage, the inlet temperature is lower than the outlet temperature.
The temperature difference between the inlet and the outlet of the first reactor 1 is not more than +/-5 ℃, and after the temperature of the catalyst bed layer reaches 265-320 ℃, the raw material methanol begins to dehydrate to generate dimethyl ether, the temperature difference of the catalyst bed layer (the temperature difference between the temperature of the top feed inlet and the temperature of the outlet of the reactor) is increased, most of the methanol is converted, the accumulated amount of reaction heat is reduced, and the heat effect is reduced. Therefore, when the temperature difference between the inlet and outlet of the first reactor 1 is not more than + -5 ℃ and the temperature of the catalyst bed layer reaches 265-.
Before the temperature of the catalyst bed in the first reactor 1 is stabilized, the first product stream generated from the first reactor 1 should be output to a flare system for combustion treatment to prevent the organic materials therein from threatening the safe operation of the plant. When the first steam pipeline 3 is not arranged, the temperature of the materials in the first reactor 1 cannot be adjusted, so that the temperature runaway condition cannot be controlled or prevented, and in order to avoid great influence on the catalyst and the components in the reactor, the feeding operation can be carried out only under the mild control condition, so that the longer time is spent. After the first steam pipeline 3 is arranged, on one hand, the catalyst bed layer in the first reactor 1 is heated to raise the temperature, so that the catalyst bed layer in the first reactor 1 reaches the reaction temperature of the reaction of synthesizing dimethyl ether by methanol gas phase dehydration as soon as possible, and the feeding time is shortened; on the other hand, the heat of adsorption of the water vapor in the catalyst pore passage and the heat of reaction for synthesizing dimethyl ether by gas phase dehydration of methanol can be sequentially and respectively released, so that the condition that the temperature runaway of the first reactor 1 is caused by the superposition of the two types of heat in the first reactor 1 is prevented. Through the control of the flying temperature condition in the first reactor 1 in the starting feeding process, the feeding speed is improved, so that the starting feeding time is shortened, the material quantity output to a torch system is reduced, and the material waste and the energy waste are reduced.
When the outlet temperature of the first reactor 1 reaches 325-345 ℃, the first reactor 1 reaches a stable feeding state. Because the first reactor 1 and the second reactor 2 can be regarded as two units connected in series during the starting and feeding, if the first unit does not reach a steady state, the second unit has no basis for adjustment, and even if the first unit is controlled to reach balance and slightly fluctuates, the second unit can be affected. Thus, the feeding of the recycled hydrocarbon product stream and the heating of the feed (here the feed refers to the recycled hydrocarbon product stream and the first product stream output via said first line 15) to the heating means 7 to 460 ℃ for feeding to the second reactor 2 are started when the outlet temperature of the first reactor 1 reaches 325-.
When the temperature of the catalyst bed layer in the second reactor 2 is 420-460 ℃, the catalyst has higher activity, and the conversion rate and the propylene selectivity of the catalyst are lower when the temperature is lower than the temperature range; above this temperature range, the catalyst will undergo an exothermic reaction, resulting in an over-temperature of the catalyst in the lower layer, and therefore, the outlet material temperature of the heating device 7 is 420-.
In one embodiment, in step (1), the nailThe feeding space velocity of the alcohol is 0.5-0.6h-1Preferably 0.53-0.57h-1For example 0.55h-1。
In one embodiment, in the step (1), the temperature of the water vapor is raised to 200-.
In one embodiment, in the step (3), the top feed of the second reactor 2 further comprises steam and is delivered to the heating device 7 through the second steam line 12, and is heated to 460 ℃ C (preferably 430 ℃ C. and 450 ℃ C., such as 440 ℃ C.) together with the first product stream output through the first line 15 and the recycle hydrocarbon product stream from the recycle hydrocarbon product stream line 8, and then sent to the first catalyst bed as the top feed of the second reactor 2.
The second reactor 2 is supplied with water vapor from the top through a second water vapor line 12, and on one hand, the water vapor can be used as a carrier to play a role of a carrier gas so as to reduce the partial pressure of raw material methanol/DME and improve the reaction selectivity and the yield of propylene products; on the other hand, the raw material methanol can be diluted, so that less raw material methanol is contacted with the catalyst in the second reactor 2, and the generation of carbon on the surface of the catalyst is delayed.
In one embodiment, in the step (3), the flow rate of the water vapor from the second water vapor line 12 is Q1, the flow rate of the recycled hydrocarbon product stream from the recycled hydrocarbon product stream line 8 is Q2, and the flow rate of the methanol from the methanol line 5 is Q3, then the temperature of the catalyst bed fed from the top of the second reactor 2 to the second reactor 2 in the step (3) reaches 480 ℃, -the ratio of (Q1+ Q2)/Q3 is increased from 1:1 to 1.2: 1.
The flow rate is the amount of fluid flowing through the effective cross section of a closed pipeline or an open channel in unit time, and is also called instantaneous flow rate. When the amount of fluid is expressed in volume, it is called the volumetric flow; when fluid volume is expressed as mass, it is referred to as mass flow. The volume of fluid flowing through a section of pipe per unit time, referred to as the volume flow of the cross-section, referred to as flow for short, is denoted by Q. The flow rate in the present invention means a volume flow rate.
In one embodiment, in the step (4), when the outlet temperature of the first reactor 1 reaches 360-.
The temperature of the side line feeding of the second heat exchanger 13 is controlled by respectively adjusting the feeding amount or the feeding proportion of the material from the second heat exchanger 13 and the first product flow from the second pipeline 16, so that the temperature runaway condition in the second heat exchanger 13 is prevented, the starting and feeding time is shortened, and the material waste and the energy waste are reduced.
In one embodiment, in the step (4), when the outlet temperature of the first reactor 1 reaches 360-; and the water vapor from the third water vapor line 14 and the mixed material of the material from the second heat exchanger 13 and the first product stream from the second line 16 are sent to the second to last catalyst beds respectively by using the first side line 9 to adjust the feed temperature of the second to last catalyst beds.
By respectively adjusting the feeding amount or the feeding proportion of the water vapor from the third water vapor pipeline 14, the material from the second heat exchanger 13 and the first product stream from the second pipeline 16, the temperature of the side feeding of the second heat exchanger 13 is further controlled, and the temperature runaway condition in the second heat exchanger 13 is prevented, so that the starting feeding time is further shortened, and the material waste and the energy waste are reduced.
The feeding amount of different materials can be adjusted through the feeding flow of different pipelines in the starting feeding process, so that the temperature of catalyst beds of the first reactor 1 and the second reactor 2 is adjusted, the damage to the catalyst and components in the reactors due to the temperature runaway condition in the feeding process is prevented, the feeding speed is increased, and the feeding time is shortened.
The driving process will be further explained with reference to the following examples
Example 1
The methanol-to-propylene system shown in figure 1 of the invention is used for starting and feeding, and the feeding process is as follows:
(1) purging and heating the methanol-to-propylene system to about 200 ℃ with nitrogen in sequence, then supplying steam to the first reactor 1 by using the first steam pipeline 3 to heat the catalyst bed layer in the first reactor 1 to about 257 ℃, then feeding the steam and methanol input through the methanol pipeline 5 into the first reactor 1 from the top to perform a methanol-to-dimethyl ether reaction to obtain a first product stream, and outputting the first product stream from the first reactor 1 to a flare system by using a flare pipeline 6;
(2) when the temperature difference between the inlet and outlet of the first reactor 1 is not more than +/-5 ℃ and the temperature of the catalyst bed layer reaches about 290 ℃, closing the flare pipeline 6 and feeding the space velocity of the methanol for 0.55h from the beginning -1The lifting time is 0.7h-1Then, the first product stream from the first reactor 1 is output to the heating device 7 through the first pipeline 15, and after the temperature is raised to about 440 ℃, the first product stream is sent to the first catalyst bed layer as the top feed of the second reactor 2, and a methanol-to-propylene reaction occurs in the second reactor 2 to obtain a second product stream; the second product stream is then passed to the polishing unit 11;
(3) when the outlet temperature of the first reactor 1 reaches about 335 ℃, inputting the recycled hydrocarbon product stream from the recycled hydrocarbon storage tank 18 and the steam from the second steam pipeline 12 into the heating device 7, raising the temperature to about 440 ℃ together with the first product stream output through the first pipeline 15, sending the recycled hydrocarbon product stream and the steam to the first catalyst bed layer of the second reactor 2 as the top feed of the second reactor 2, and continuing the methanol-to-propylene reaction in the second reactor 2 to obtain a second product stream; the second product stream is then passed on to the polishing unit 11 for separation to yield a recycle hydrocarbon product stream comprising C2, C4, C5 and C6 components;
then the recycled hydrocarbon product stream from the refining unit 11 is also fed into the heating device 7 to be heated to about 440 ℃ together with the first product stream output through the first pipeline 15, the recycled hydrocarbon product stream from the recycled hydrocarbon storage tank 18 and the steam from the second steam pipeline 12, and then is continuously fed to the first catalyst bed as the top feed of the second reactor 2 to continue the methanol-to-propylene reaction to obtain a second product stream; to the extent that the recycle hydrocarbon product stream from the polishing unit 11 is able to continuously meet the feed requirements of the second reactor 2, the supply of recycle hydrocarbon product stream from recycle hydrocarbon storage tank 18 to the heating means 7 is stopped;
(4) When the outlet temperature of the first reactor 1 reaches about 365 ℃, the first product flow from the third pipeline 17 is cooled to about 225 ℃ by the second heat exchanger 13, then the mixed material of the water vapor from the third water vapor pipeline 14, the material from the second heat exchanger 13 and the first product flow from the second pipeline 16 is respectively sent to the second to the last catalyst bed layer through the first side pipeline 9, and the water from the second side pipeline 10 is also sent to the second to the last catalyst bed layer, so as to adjust the temperature of the second to the last catalyst bed layer, when the temperature of the catalyst bed layer of the second reactor 2 is stabilized at about 485 ℃, the start-up feeding process is completed, and the start-up feeding time is only 2 hours.
Comparative example 1
Compared with the example 1, in the methanol to propylene system for startup and feed, the first steam pipeline 3 for supplying steam to the first reactor 1, the first heat exchanger 4 for raising the temperature of the steam from the first steam pipeline 3, the second steam pipeline 12 for supplying steam to the second reactor 2 from the top, the third pipeline 17 for outputting part of the first product stream from the first reactor 1 to feed the second reactor 3 from the side line, the second heat exchanger 13 for lowering the temperature of the first product stream from the third pipeline 17 and then feeding the first product stream to the first side line pipeline 9, and the third steam pipeline 14 for feeding the steam to the first side line pipeline 9 are not provided;
Compared with the example 1, during the feeding process, only methanol is fed to the top of the first reactor 1, and water vapor is not fed; feeding only the recycle hydrocarbon product stream and the first product stream, and no steam, to the heating device 7; the first product stream from the second line 16 is fed to the side of the second reactor 2 only via the first side line 9, without feeding steam and the first product stream from the third line 17 and reduced in temperature via the second heat exchanger 13; the starting and feeding time is 11 hours.
Comparison of results
In example 1, the start-up and feed time was 2 hours, and the methanol feed consumption of the torch system was 128 tons, calculated as the methanol consumption of the first reactor and the second reactor, each having a 100% feed load, of 110 t/h; the yield of propylene is 22.53 percent, the yield of LPG is 7.79 percent, the yield of mixed aromatics is 9.7 percent, and the total yield is 40.08 percent;
the methanol amount of the methanol raw material entering the second reactor 2 to participate in the reaction is calculated according to 220 tons, and is calculated according to the market price of 2000 yuan/ton methanol, 8000 yuan/ton propylene, 5000 yuan/ton LPG and 6000 yuan/ton mixed aromatic hydrocarbon, in the feeding of one-time driving,
the consumption of methanol was: x1 ═ 2000 yuan/ton × (128+220) ton;
the income of the product is as follows: y1 is 8000 yuan/ton × 220 ton × 22.53% (propylene) +5000 yuan/ton × 220 ton × 7.79% (LPG) +6000 yuan/ton × 220 ton × 9.7% (mixed aromatics).
In comparative example 1, the amount of methanol consumed by the torch system was 713 tons, also calculated as the methanol consumption of 110t/h for 100% feed load in both the first reactor and the second reactor; the yield of propylene is 8.27 percent, the yield of LPG is 6.92 percent, the yield of mixed aromatic hydrocarbon is 3.0 percent, and the total yield is 18.19 percent;
the methanol amount of the methanol raw material entering the second reactor 2 to participate in the reaction is calculated according to 220 tons, and is calculated according to the market price of 2000 yuan/ton methanol, 8000 yuan/ton propylene, 5000 yuan/ton LPG and 6000 yuan/ton mixed aromatic hydrocarbon, so that the consumption of the methanol in the feeding of one-time driving is as follows: x2 ═ 2000 yuan/ton X (713+220) ton;
the income of the product is as follows: y2 is 8000 yuan/ton × 220 ton × 8.27% (propylene) +5000 yuan/ton × 220 ton × 6.92% (LPG) +6000 yuan/ton × 220 ton × 3.0% (mixed aromatics).
Therefore, compared with the start-up feeding time of 11 hours in comparative example 1, in the example 1 of the present application, the start-up feeding time is only 2 hours, which shortens 9 hours, and not to say, the labor cost and energy consumption in the 9 hours, only considering the saving of methanol raw material and the improvement of product yield, the economic benefit in one start-up feeding process is as follows:
X2-X1 ═ 2000 yuan/ton × (713-;
Y2-Y1 is 8000 yuan/ton × 220 ton x (22.53% -8.27%) +5000 yuan/ton × 220 ton x (7.79% -6.92%) +6000 yuan/ton × 220 ton x (9.7% -3.0%) + 34.81 ten thousand yuan;
the total amount is 151.81 ten thousand yuan.
Therefore, the system and the method for feeding the methanol can greatly shorten the time for feeding the methanol, save a large amount of methanol raw materials, improve the product yield and bring huge economic benefits.
Claims (11)
1. A method for starting a car and feeding materials by using a methanol-to-propylene system is characterized in that the methanol-to-propylene system comprises the following steps:
a first reactor (1) for carrying out a methanol to dimethyl ether reaction to obtain a first product stream; the first product stream comprises dimethyl ether, water, and unreacted methanol; the first product stream is output via a first product stream line; the first product stream lines comprise a flare line (6), a first line (15) and a second line (16) for outputting the first product streams from the first reactor (1) respectively, and the flare line (6) for outputting a part of the first product streams from the first reactor (1) to a flare system;
a second reactor (2) for carrying out the reaction of the first product stream to propylene to obtain a second product stream; and a plurality of catalyst beds are arranged in the second reactor (2) along the longitudinal direction;
A first steam line (3) for providing steam to the first reactor (1);
heating means (7) for heating the first product stream from the first line (15) and the recycle hydrocarbon product stream from the recycle hydrocarbon product stream line (8) to elevated temperatures for feeding to the first catalyst bed as a top feed to the second reactor (2);
a first side line (9) for receiving a first product stream from the second line (16) and feeding the received material to the second to last catalyst beds, respectively;
a second side line (10) for feeding water to the second to last catalyst beds, respectively;
a polishing unit (11) for separating the second product stream to obtain a recycle hydrocarbon product stream comprising C2, C4, C5 and C6 components, the recycle hydrocarbon product stream being fed at least in part through the recycle hydrocarbon product stream line (8) to the heating device (7);
a recycle hydrocarbon storage tank (18) for providing a recycle hydrocarbon product stream to the heating device (7);
the method comprises the following steps:
(1) purging and heating the methanol to propylene system to 180-220 ℃ sequentially by using nitrogen, then supplying water vapor to the first reactor (1) by using the first water vapor pipeline (3) to heat the catalyst bed layer in the first reactor (1) to 255-260 ℃, then performing a methanol to dimethyl ether reaction in the first reactor (1) by using the input methanol to obtain a first product stream, and outputting the first product stream from the first reactor (1) to a flare system by using a flare pipeline (6);
(2) When the temperature difference between the inlet and outlet of the first reactor (1) is not more than +/-5 ℃ and the temperature of the catalyst bed layer reaches 265--1Outputting the first product flow from the first reactor (1) through the first pipeline (15) to the heating device (7) for temperature increaseAfter the temperature is up to 420 ℃ and 460 ℃, the second product is taken as the top feed of the second reactor (2) and sent to the first catalyst bed layer, and the reaction of preparing propylene from methanol occurs in the second reactor (2) to obtain a second product stream; the second product stream is then conveyed to the polishing unit (11);
(3) when the outlet temperature of the first reactor (1) reaches 325-; then continuing to convey the second product stream to the polishing unit (11) for separation to yield a recycle hydrocarbon product stream comprising C2, C4, C5, and C6 components;
Then the recycled hydrocarbon product stream from the refining unit (11) is also input into the heating device (7) and is heated to 420 ℃ and 460 ℃ together with the first product stream output by the first pipeline (15) and the recycled hydrocarbon product stream from the recycled hydrocarbon storage tank (18), and then the recycled hydrocarbon product stream is continuously used as the top feed of the second reactor (2) and sent to the first catalyst bed layer to continuously generate the methanol-to-propylene reaction in the second reactor (2) to obtain a second product stream; to the extent that the recycle hydrocarbon product stream from the polishing unit (11) can continue to meet the feed requirements of the second reactor (2), stopping the supply of recycle hydrocarbon product stream from recycle hydrocarbon storage tank (18) to the heating means (7);
(4) when the outlet temperature of the first reactor (1) reaches 360-.
2. The method according to claim 1, wherein the methanol to propylene system further comprises a second steam line (12) for supplying steam overhead to the second reactor (2); the heating device (7) is used for heating the first product flow from the first pipeline (15), the water vapor from the second water vapor pipeline (12) and the circulating hydrocarbon product flow from the circulating hydrocarbon product flow pipeline (8) to increase the temperature, so that the first product flow is fed to the first catalyst bed layer as the top feed of the second reactor (2).
3. The method according to claim 2, wherein the methanol to propylene system further comprises a first heat exchanger (4) for warming the water vapor from the first water vapor line (3) to feed it together with methanol from the methanol line (5) as top of the first reactor (1).
4. The method according to claim 3, wherein in the methanol to propylene system, the first product stream line further comprises a third line (17) for outputting a part of the first product stream from the first reactor (1); the methanol-to-propylene system further comprises a second heat exchanger (13) for cooling the first product stream from the third line (17) and feeding the cooled first product stream into the first side line pipeline (9).
5. The method of claim 4, wherein the methanol to propylene system further comprises a third steam line (14) for feeding steam into the first side line conduit (9).
6. The method of claim 5,
in the step (1), the feeding airspeed of the methanol is 0.5-0.6h-1。
7. The method of claim 6,
in the step (1), the temperature of the steam is raised to 200-220 ℃ by using the first heat exchanger (4) before being supplied to the first reactor (1).
8. The method of claim 6 or 7,
in the step (3), the top feed of the second reactor (2) further comprises steam, and is delivered to the heating device (7) through the second steam line (12), and is heated to 460 ℃ together with the first product stream outputted through the first line (15) and the recycle hydrocarbon product stream from the recycle hydrocarbon product stream line (8), and then is sent to the first catalyst bed as the top feed of the second reactor (2).
9. The process according to claim 8, wherein in step (3), the flow rate of the steam from the second steam line (12) is Q1, the flow rate of the recycled hydrocarbon product stream from the recycled hydrocarbon product stream line (8) is Q2, and the flow rate of the methanol from the methanol line (5) is Q3, and the catalyst bed temperature in step (3) which is fed overhead from the second reactor (2) to the second reactor (2) reaches 480 ℃. + 490 ℃, and the ratio of (Q1+ Q2)/Q3 is increased from 1:1 to 1.2: 1.
10. Method according to any of claims 6, 7 and 9, characterized in that in step (4), when the outlet temperature of the first reactor (1) reaches 360-375 ℃, the first product stream from the third line (17) is further cooled to 220-235 ℃ by the second heat exchanger (13), and then the cooled material is received by the first side line pipeline (9) and sent to the second to last catalyst beds respectively as side feed of the second reactor (2) together with the first product stream from the second line (16) to adjust the feed temperature of the second to last catalyst beds.
11. The method as claimed in claim 10, wherein in step (4), when the outlet temperature of the first reactor (1) reaches 360-375 ℃, the third steam pipeline (14) is used to supply steam to the second reactor (2) from the side; and the water vapor from the third water vapor line (14) and the mixture of the material from the second heat exchanger (13) and the first product stream from the second line (16) are sent to the second to last catalyst beds respectively by means of the first side line conduit (9) to adjust the feed temperature of the second to last catalyst beds.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910468188.5A CN110183301B (en) | 2019-05-31 | 2019-05-31 | Methanol-to-propylene system and method for starting and feeding by using same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910468188.5A CN110183301B (en) | 2019-05-31 | 2019-05-31 | Methanol-to-propylene system and method for starting and feeding by using same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110183301A CN110183301A (en) | 2019-08-30 |
| CN110183301B true CN110183301B (en) | 2022-06-28 |
Family
ID=67719198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910468188.5A Active CN110183301B (en) | 2019-05-31 | 2019-05-31 | Methanol-to-propylene system and method for starting and feeding by using same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110183301B (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101130488A (en) * | 2007-08-08 | 2008-02-27 | 四川泸天化绿源醇业有限责任公司 | Catalyzer temperature-elevating method used for producing dimethyl ether by vapor phase method |
| CN101629090A (en) * | 2009-08-14 | 2010-01-20 | 山西恒扬科技有限公司 | Technique for producing hydrocarbon products rich in propylene by methanol |
| CN103980082A (en) * | 2014-05-22 | 2014-08-13 | 神华集团有限责任公司 | Method for preparing propylene from methanol |
| CN106831288A (en) * | 2017-03-06 | 2017-06-13 | 江苏天诺新材料科技股份有限公司 | The MTP methods of mixed alcohol side entry feed |
| CN110054539A (en) * | 2019-05-10 | 2019-07-26 | 国家能源投资集团有限责任公司 | A kind of preparing propylene from methanol device and method |
-
2019
- 2019-05-31 CN CN201910468188.5A patent/CN110183301B/en active Active
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101130488A (en) * | 2007-08-08 | 2008-02-27 | 四川泸天化绿源醇业有限责任公司 | Catalyzer temperature-elevating method used for producing dimethyl ether by vapor phase method |
| CN101629090A (en) * | 2009-08-14 | 2010-01-20 | 山西恒扬科技有限公司 | Technique for producing hydrocarbon products rich in propylene by methanol |
| CN103980082A (en) * | 2014-05-22 | 2014-08-13 | 神华集团有限责任公司 | Method for preparing propylene from methanol |
| CN106831288A (en) * | 2017-03-06 | 2017-06-13 | 江苏天诺新材料科技股份有限公司 | The MTP methods of mixed alcohol side entry feed |
| CN110054539A (en) * | 2019-05-10 | 2019-07-26 | 国家能源投资集团有限责任公司 | A kind of preparing propylene from methanol device and method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110183301A (en) | 2019-08-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US20140194663A1 (en) | Oxidative Coupling of Hydrocarbons as Heat Source | |
| CN102337154B (en) | Method for catalytic conversion production of propylene and light aromatics | |
| CN103571530B (en) | Wax catalysis cracking is for the method for low-carbon alkene | |
| CN102276386B (en) | Production method of light olefins | |
| CN103772092B (en) | Methanol conversion is the reaction unit of low-carbon alkene | |
| CN101898927B (en) | Method for preparing light olefins from alcohols | |
| CN105349172A (en) | Naphtha raw material catalysis cracking method | |
| CN103936542B (en) | A kind of olefins by catalytic cracking system and method improving alkene total conversion rate | |
| CN101293804B (en) | Fluidizer and method for preparing ethylene with ethanol dehydration | |
| CN101293801A (en) | Method for preparing dimethyl ether, low carbon olefin hydrocarbon with combination of methanol dehydration catalytic pyrolysis | |
| CN106831288B (en) | The MTP method of mixed alcohol side entry feed | |
| CN105130729A (en) | Durene-poly-generation technological method and production system for preparing light hydrocarbon through methyl alcohol | |
| CN103333040B (en) | Low energy consumption propylene production technology | |
| CN110183301B (en) | Methanol-to-propylene system and method for starting and feeding by using same | |
| CN105130730A (en) | Technological method for preparing light hydrocarbons through methanol by means of continuous regeneration moving beds and production system | |
| CN107721791B (en) | Preparation system and preparation method for preparing propylene from methanol | |
| CN102875294B (en) | Start-up method of reaction-regeneration device for preparing low-carbon olefins from methanol | |
| CN101700483B (en) | Gasoline producing riser reactor | |
| CN103435432B (en) | A kind of take petroleum naphtha as the method for raw materials for ethylene production propylene | |
| CN203170305U (en) | Combined-heat-exchange multi-shell-side fixed bed production equipment for preparing olefin from methanol | |
| CN103739418B (en) | Improve the method for yield of light olefins in preparing light olefins from methanol technique | |
| CN105396514A (en) | Apparatus and method for preparing gasoline from methanol | |
| CN102875288B (en) | Method for producing low-carbon olefins | |
| CN102875295B (en) | Production method of low-carbon olefins | |
| CN102875304B (en) | Method for preparing low carbon olefins from methanol and naphtha |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |