CN108329186B

CN108329186B - Methanol conversion method of cascade moving bed

Info

Publication number: CN108329186B
Application number: CN201710038113.4A
Authority: CN
Inventors: 李明罡; 罗一斌; 廖祖维; 张巍; 舒兴田
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2017-01-18
Filing date: 2017-01-18
Publication date: 2021-01-08
Anticipated expiration: 2037-01-18
Also published as: CN108329186A

Abstract

The invention provides a methanol conversion method of a cascade moving bed, which comprises a reaction process in n moving bed reactors and a process of activating catalysts in n-1 catalyst lifters. The method avoids the increase of energy consumption and catalyst poisoning caused by the process water serving as a return diluent, promotes the conversion of the catalyst to methanol and improves the selectivity of propylene by the reaction of the aromatic hydrocarbon-containing material flow and the carbon deposition catalyst, reduces the energy consumption and ensures the stability of the product distribution.

Description

Methanol conversion method of cascade moving bed

Technical Field

The present invention relates to a process and a reaction system for the conversion of methanol, and more particularly to a process for the conversion of methanol to propylene using a moving bed.

Background

Propylene is an important petrochemical basic raw material next to ethylene, and is mainly derived from catalytic cracking of petroleum, steam cracking of naphtha, dehydrogenation of propane (butane) and the like. In recent years, the global demand for propylene has rapidly increased due to the pulling of downstream industries of propylene, and the trend of shortage of propylene resource supply has been intensified year by year.

The coal resources in China are rich, the large-scale industrial technology for preparing methanol from coal is mature day by day, and with the industrialization of the MTP technology for producing propylene from methanol, a feasible way is opened for producing propylene by a clean coal chemical route.

The technological route of Methanol To Propylene (MTP) technology generally adopts a 'two-stage method' reaction process, namely a first stage methanol to dimethyl ether (MTD) reactor converts part of methanol into dimethyl ether (DME), a first stage reaction product is mixed with a diluent and then enters a second stage MTP reactor for hydrocarbon synthesis reaction, and a second stage reaction product is separated, compressed and refined to obtain a qualified product. In the other 'one-step' MTP process, methanol is directly mixed with diluent and then enters an MTP reactor for hydrocarbon synthesis reaction, and the reaction product is separated, compressed and refined to obtain a qualified product.

U.S. patent application 2003/0139635A1 discloses a process for producing propylene from methanol. Methanol is partially converted into dimethyl ether through a first reactor, and then a propylene-containing product is generated through a second fixed bed reactor filled with a Pentasil type shape selective zeolite catalyst. The catalyst has a particle size of 300-600 m²Specific surface area per gram, pore volume of 0.3-0.8 mL/g, alkali metal content less than 380ppm and ZnO and CdO content less than 0.1%. Wherein part of the first reaction outlet material and steam directly enter the second reactor, and part of the intermediate product after the propylene is separated is recycled and recycled to the second reactor. The reaction temperature of the second reactor was 350-.

Still other techniques use co-feeding of methanol and petroleum hydrocarbons to modulate the product distribution and selectivity of the product light olefins. Chinese patent application No. 99806355, X proposes that under the action of zeolite catalyst with alpha value less than 10, reaction temperature of 350-480 deg.C and partial pressure of methanol and/or dimethyl ether over 70kPa, the co-feed of methanol and/or dimethyl ether and aromatic compound is controlled to have conversion rate of methanol and/or dimethyl ether less than 90%, so as to obtain light olefin product, especially to raise the selectivity of feed aromatic hydrocarbon to ethylene. Aromatic co-feeds include organic feeds having an aromatics content greater than 10 wt%, including but not limited to benzene, toluene, xylenes, C₉₊Heavy monoliths, light reformate, full range reformate or any straight run, coker gasoline fraction, FCC naphtha and coal derived aromatics, and may also include fractions produced by the aromatization reaction of the methanol feed itself. The molar ratio of methanol and/or dimethyl ether to aromatic feed is generally greater than 5: avoiding too high a concentration of aromatics leading to excessive coking, increased separation volume and recycle flow and reduced added value of product selectivity.

Chinese patent application 200710180086.0 proposes C to be produced by itself in a methanol-to-propylene device₇The aromatics feed is recycled to the oxygenate to olefins reactor for co-feeding with the oxygenate feed to achieve the simultaneous production of aromatics and light olefins.

Chinese patent application 201010607910.8 discloses the use of modified ZSM-5 molecular sievesA method for catalyzing methanol coupled naphtha catalytic cracking reaction by using a catalyst. The method uses a ZSM-5 molecular sieve catalyst containing lanthanum and phosphorus, the reaction temperature is 550-^-1Under the reaction conditions of (1).

Chinese patent application 201310512646.3 discloses a method for preparing aromatic hydrocarbon from methanol or dimethyl ether, wherein the methanol or dimethyl ether is mixed with one or more of dry gas, rich gas, liquefied gas, straight run gasoline and light naphtha to contact and react with a catalyst under the conditions of reaction temperature of 350-650 ℃ and pressure of 0.1-2.0 MPa.

U.S. patent application No. US6680418B2 discloses a process for producing light olefins in which a co-feed of methanol and/or dimethyl ether and at least 10 wt.% of polymethylbenzene is contacted with a porous crystalline material catalyst. The reaction temperature is 250 ℃ and 500 ℃, and the partial pressure of the methanol and/or the dimethyl ether is 35-1725 kPa.

In these fixed bed processes for producing olefins from methanol, the initial catalyst operation can bring the methanol conversion rate close to 100%, but as the operation time increases, the catalyst surface carbon deposition causes the methanol conversion rate and the olefin selectivity to gradually decrease. In a typical MTP process, the average one-way lifetime of a shape-selective catalyst is about 667h, and the total service life is about 8000h [ guangzhou chemical, 2013, 41 (17): 192]. The MTP reaction is a typical acid catalytic reaction, and olefin generated in the reaction is very active and is easy to further condense to generate carbon deposit, so that the coverage of acid centers on the surface of the catalyst and the blockage of pore channels are caused, and the activity and the selectivity of the catalyst are gradually reduced. Thus, the MTP catalyst has a relatively short on-stream period and requires frequent regeneration. To ensure continuous production, the MTP reactor is usually operated with two reactors and one reactor.

Moving bed technology allows continuous reaction regeneration of the catalyst to the attention of researchers. CN101023047B discloses a process for converting alcoholic oxygenates to propylene using moving bed technology and an etherification step. The process method comprises the steps of firstly converting methanol into dimethyl ether in a first reaction zone by using a gamma-Al 2O3 catalyst, then converting a return hydrocarbon consisting of an effluent mixture of the first reaction zone, part of by-product water, ethylene and part of C4+ olefin into a product rich in propylene in a second reaction zone by using a moving bed reactor and a ZSM-5 or SAPO-34 molecular sieve catalyst, wherein the residence time of the catalyst in the reaction zone is shorter than 300 h.

CN101367701A discloses a method for converting oxygen-containing compounds into propylene by using moving bed technology, which adopts two-stage reaction zones, the oxygen-containing compound raw material is generated into products in the first stage reaction zone, and then C in the products is converted₅The components are introduced into a second reaction zone to regenerate the catalyst for pre-carbon deposition, the catalyst of the pre-carbon deposition in the second reaction zone is recycled for the reaction in the first reaction zone, and finally the catalyst is introduced into a regenerator.

CN102344328A discloses a semi-continuous process for converting methanol to propylene using moving bed technology, comprising: mixing a molecular sieve catalyst and a diluent, introducing the mixture into a first reaction zone, introducing a methanol raw material into the first reaction zone, and carrying out contact reaction with the molecular sieve catalyst to generate a first material flow; introducing the first material flow into a second reaction zone to contact and react with a molecular sieve catalyst to generate a second material flow; after heat exchange, the second stream of methanol raw material is dehydrated and deoxidized and then separated to obtain a second reaction zone return material, a second reaction zone discharge material and a third reaction zone feed material, wherein the second reaction zone return material is merged into the first stream of material; feeding the feed into the third reaction zone to contact with a molecular sieve catalyst to generate a third material flow; the molecular sieve catalyst is conveyed to a regenerating device periodically by a catalyst collector for regeneration and is intermittently merged into the molecular sieve catalyst for circulation.

CN102942435A discloses a reaction process for converting methanol into propylene using moving bed technology, comprising the following steps: (1) mixing and heating a methanol raw material and return hydrocarbon, introducing the mixture into a pre-reaction zone together, and contacting the mixture with a regenerated catalyst to carry out etherification reaction to generate a primary product stream; (2) the primary product flow is subjected to heat exchange with a diluent and then is introduced into a main reaction zone to carry out olefin preparation reaction with a primary carbon-deposited catalyst, and a secondary product flow rich in propylene is obtained from the outlet of the reactor; (3) sending the secondary product flow to a separation zone, dehydrating and deoxidizing to obtain propylene and other byproducts, and removing ethylene and part C in the other byproducts₄Olefin, C₄Alkane, C₅Hydrocarbons, C₆The hydrocarbons are combined and returned to the pre-reaction zone as return hydrocarbons.

The process method utilizing continuous reaction-regeneration relates to the transportation of the catalyst between reaction zones and reaction regeneration zones, needs a special stripping device, needs great transportation power and consumes excessive energy; in addition, the technical defects that the energy consumption is increased by adopting the process water generated by converting the methanol as the return diluent and the process water contains impurities to poison the catalyst are overcome.

Disclosure of Invention

The object of the present invention is to provide a methanol conversion process which differs from the prior art processes in which the reaction is carried out using a moving bed.

The methanol conversion method of the cascade moving bed provided by the invention comprises a reaction process in n moving bed reactors and a process of activating catalysts in n-1 catalyst lifters, wherein n is more than or equal to 2;

dividing a mixed material of an oxygen-containing compound raw material containing methanol and return hydrocarbon into n parts, wherein the first part is introduced into a first moving bed reactor to be in contact reaction with a regenerated catalyst to generate a first product flow rich in propylene; the carbon-deposited catalyst flows out of the bottom of the first moving bed reactor;

contacting a reactivator containing aromatic hydrocarbon material flow with a catalyst of carbon deposit in a first catalyst lifter and lifting the reactivator and the catalyst to the top of a second moving bed reactor to generate a first aromatic hydrocarbon mixed material flow and an activated catalyst;

introducing a second part of the mixture of the oxygen-containing compound raw material containing methanol and the returned hydrocarbon which is divided into n parts into a second moving bed reactor to carry out contact reaction with an activated catalyst to generate a second product flow rich in propylene; the carbon-deposited activated catalyst flows out of the bottom of the second moving bed reactor;

the reactivating agent containing aromatic hydrocarbon material flow is contacted with the activated catalyst of carbon deposit in a second catalyst lifter and lifted to the top of a second moving bed reactor to generate a second aromatic hydrocarbon mixed material flow and the activated catalyst; until the time when the user wants to use the device,

introducing an n-1 part of a mixed material which is divided into n parts of an oxygen-containing compound raw material containing methanol and returned hydrocarbon into an n-1 moving bed reactor to carry out contact reaction with an activated catalyst to generate an n-1 product flow rich in propylene; contacting a reactivator containing aromatic hydrocarbon material flow with an activated catalyst of carbon deposit in an n-1 catalyst lifter and lifting the reactivator and the activated catalyst to the top of an n-1 moving bed reactor to generate an n-1 aromatic hydrocarbon mixed material flow and the activated catalyst;

introducing the nth part of the mixture of the oxygen-containing compound raw material containing methanol and the return hydrocarbon into the nth moving bed reactor to carry out contact reaction with the activated catalyst to generate an nth product flow rich in propylene; the activated catalyst with carbon deposit flows out of the bottom of the nth moving bed reactor and enters a regenerator for coke burning regeneration to obtain the regenerated catalyst which is circulated back to the first moving bed reactor;

feeding the first to nth product streams rich in propylene and the first to nth-1 aromatic mixture streams into a three-phase separator for separation, wherein a water phase is recovered as a sewage stream, an oil phase is fed into a dearomatization tower for separation, and a gas phase is fed into a deethanization tower;

c at the top of the dearomatization tower₅And C₆The hydrocarbon stream is partially used as a product and the remaining portion is used as a part of the returned hydrocarbons; part of aromatic hydrocarbon-containing material flow at the bottom of the dearomatization tower is taken as a product, and the rest part is taken as at least one part of the aromatic hydrocarbon-containing material flow;

a portion of the overhead stream from said deethanizer is used as fuel gas product and the remainder is used as a portion of said return hydrocarbons; the tower bottom material flow of the deethanizer enters into the de-C₄A tower;

said de-C₄The overhead stream of the tower enters a propylene product separation system, and the C removal is carried out₄The bottom stream of the column, partly as C₄Hydrocarbon product, the remainder being part of said returned hydrocarbons.

The method of the invention adopts continuous reaction regeneration circulation, the carbon deposition catalyst is treated by using the material flow containing aromatic hydrocarbon, the activity of the catalyst can be kept stable, more reaction raw materials containing methanol are treated under a unit catalyst, the composition of the product is stable, and the selectivity of propylene is improved; the process water is not used as a diluent and is returned to the oxygen-containing compound conversion reactor, so that the increase of energy consumption and catalyst poisoning are avoided, the device is stable to operate, and the energy consumption is saved.

Drawings

FIG. 1 is a schematic diagram of a methanol to propylene process with a two-stage cascade moving bed reactor according to the present invention.

FIG. 2 is a schematic diagram of a methanol to propylene process with three cascaded moving bed reactors according to the present invention.

FIG. 3 is a schematic diagram of a methanol to propylene process with a four-stage cascade moving bed reactor according to the present invention.

Detailed Description

The methanol conversion method of the cascade moving bed provided by the invention comprises a reaction process in n moving bed reactors and a process of activating catalysts in n-1 catalyst lifters, wherein n is more than or equal to 2.

The method provided by the invention is at least carried out in n moving bed reactors and n-1 catalyst lifters. Said n is preferably 2, 3, 4 or 5. For example, when n is 2, it is a combination of "2 moving bed reactors and 1 catalyst riser"; when n is 2, the catalyst is the combination of 3 moving bed reactors and 2 catalyst lifters; when n is 4, it is a combination of "4 moving bed reactors, 3 catalyst lifters", or the like.

The oxygenate feedstock of the present invention may comprise methanol, dimethyl ether or a mixture comprising methanol and dimethyl ether.

The invention uses a small ball catalyst containing a shape-selective molecular sieve in the moving bed methanol-to-propylene reactor to convert oxygen-containing compounds and return hydrocarbon into hydrocarbon products rich in propylene. The reaction conditions are that the reaction temperature is 300-550 ℃, the reaction pressure is 0.01-1.0 MPa, and the mass airspeed of the oxygen-containing compound is 0.01-100 h^-1The mass ratio of the returned hydrocarbon to the oxygen-containing compound is 0-10.0, and the residence time of the catalyst in the reactor is 1-1000 h. The preferable reaction temperature is 450-500 ℃, the reaction pressure is 0.05-0.3 MPa, and the mass space velocity of the oxygen-containing compound feeding is 0.1-10 h^-1Returning substances of hydrocarbons and oxygen-containing compoundsThe amount ratio is 0.2-2.0, and the residence time of the catalyst in the reactor is 50-500 h.

The shape-selective molecular sieve pellet catalyst comprises a molecular sieve porous crystalline material with the pore diameter larger than the critical diameter of an aromatic compound, and the material can catalyze methanol gas-phase dehydration reaction to generate hydrocarbon products such as ethylene, propylene and the like. Such shape selective molecular sieves include, but are not limited to, ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, MCM-22, IM-5, MOR, Beta, SAPO-11, SAPO-5, SAPO-31, and the like, with ZSM-5 and ZSM-11 being preferred.

The shape-selective molecular sieve pellet catalyst can be prepared by mixing the molecular sieve porous crystalline material with various binders or filling matrix materials into pellets with the diameter of 1.0-3.0 mm so as to meet the filling requirement of a moving bed MTP reactor. The binder comprises one or a mixture of more of silicon oxide, aluminum oxide, amorphous silicon aluminum, titanium oxide, zirconium oxide and magnesium oxide. The filling matrix material comprises one or more of clay, diatomite, attapulgite, hydrotalcite and the like.

In the method, one of the functions of the catalyst lifter is that the aromatic hydrocarbon-containing fraction is contacted with the carbon deposition catalyst, the aromatic hydrocarbon-containing fraction is subjected to disproportionation and other reactions on the surface of the catalyst, and the composition of active intermediates on the surface of the catalyst is modulated, so that the conversion rate of methanol and the selectivity of propylene are greatly improved after the aromatic hydrocarbon-containing fraction enters a subsequent cascade of moving bed reactors. Another function of the catalyst riser is to lift the coked catalyst from the bottom of the moving bed reactor to a height above the top of the moving bed to accommodate the movement of catalyst in the secondary MTP reactor. The reaction temperature in the catalyst lifter is 250-550 ℃, the reaction pressure is 0.05-1 MPa, and the mass space velocity of the aromatic hydrocarbon-containing fraction is 0.01-10 h^-1The contact time is 0.01-100 h; the preferable reaction temperature is 350-500 ℃, the reaction pressure is 0.1-0.5 MPa, and the mass space velocity of the fraction containing aromatic hydrocarbon is 0.03-3 h^-1The contact time is 0.1-50 h.

In the process of the present invention, the regenerator removes carbonaceous material from the catalyst by burning the char from the catalyst at a sufficient temperature and oxygen concentration. The conditions employed are those well known to those skilled in the art.

In the method of the invention, the return hydrocarbon in the mixed feed of the moving bed reactor comprises C generated after the conversion of the oxygen-containing compound₂-、C₄、C₅And C₆Product, but not water produced by oxygenate conversion or added. This is because the vaporization cycle of water consumes a lot of energy, and the cycle water may contain harmful impurities to permanently poison the catalyst, and more importantly, the reaction in the catalyst riser of the present invention improves the activity and selectivity of the catalyst, thereby avoiding the use of steam diluent and still obtaining high propylene yield.

The process of the invention, when n is 2, is carried out in a reactor comprising two moving beds and a catalyst riser.

A methanol conversion method of a cascade moving bed comprises a reaction process carried out in a first moving bed reactor and a second moving bed reactor and a process of activating a catalyst in a catalyst lifter:

introducing a first part of a mixed material of an oxygen-containing compound raw material containing methanol and returned hydrocarbon into a first moving bed reactor to perform contact reaction with a regenerated catalyst to generate a first product flow rich in propylene; the carbon-deposited catalyst flows out of the bottom of the first moving bed reactor;

contacting aromatic hydrocarbon-containing material flow and carbon-deposited catalyst in a catalyst lifter and lifting the catalyst to the top of a second moving bed reactor to generate aromatic hydrocarbon-mixed material flow and activated catalyst;

introducing the oxygen-containing compound raw material containing methanol and a second part in the mixed flow of the returned hydrocarbon into a second moving bed reactor to perform contact reaction with the activated catalyst to generate a second product flow rich in propylene; the carbon deposited catalyst flows out of the bottom of the second moving bed reactor, enters a regenerator for coke burning regeneration to obtain the regenerated catalyst and circulates back to the first moving bed reactor;

feeding the first product flow rich in propylene, the second product flow rich in propylene and the mixed aromatic substance flow into a three-phase separator for separation, wherein a water phase is recovered as a sewage substance flow, an oil phase is fed into a dearomatization tower for separation, and a gas phase is fed into a deethanization tower;

c at the top of the dearomatization tower₅And C₆The hydrocarbon stream is partially used as a product and the remaining portion is used as a part of the returned hydrocarbons; part of aromatic hydrocarbon-containing material flow at the bottom of the dearomatization tower is taken as a product, and the rest part of the aromatic hydrocarbon-containing material flow is taken as a part of the aromatic hydrocarbon-containing material flow;

FIG. 1 is a schematic diagram of a methanol to propylene process with two cascaded moving bed reactors of the present invention, illustrating the process of the present invention including the reaction processes in the first and second moving bed reactors and the catalyst activation process in one catalyst riser. In order to simplify the description of the invention, the figures do not include illustrations of heaters, heat exchangers, coolers, valves, control devices, and conventional devices known to those skilled in the art, except for the equipment necessary to understand the invention.

In FIG. 1, preheated oxygenate feed 10 is combined with three streams from the system's subsequent separation system, including C from deethanizer 17₂Stream 174, self-deC₄C of column 18₄Stream 184 and C from dearomatization column 19₅C₆Stream 194, a mixed feed is obtained and heated, a part of stream 111 of the mixed feed enters the first moving bed reactor 11 to contact with the pellet catalyst containing the shape-selective molecular sieve, the oxygenate is converted into a first product stream 112 rich in propylene and flows out from the top of the first moving bed reactor 11, and the pellet catalyst material 113 regenerated by the regenerator 13 enters from the top of the first moving bed reactor 11Then the carbon deposit on the surface of the carbon deposit contacted with the material flow 111 flows out from the bottom of the first moving bed reactor 11 to form a carbon deposit catalyst 114, the carbon-deposited catalyst 114 is lifted by contacting with an aromatic hydrocarbon-containing stream 196 flowing out of a dearomatization tower 19 in a catalyst lifter 21, a first mixed aromatic product stream 212 at the outlet of the catalyst lifter 21 is mixed with the first product stream 112, an activated catalyst 123 at the outlet of the catalyst lifter 21 enters from the top of the second moving bed reactor 12, and the other part of the feed stream 121 separated from the mixed feed reacts in a contact manner, so that the oxygen-containing compounds are converted into a second product stream 122 rich in propylene, the second product stream 122 flows out from the top of the reactor 12, the second product stream 122 is mixed with the first product stream 112 and the first mixed aromatic product stream 212 into a mixed product stream 151, the coked catalyst 124 flowing out from the bottom of the second moving bed reactor enters a regenerator 13 to be burnt in a contact manner with the oxygen-containing gas stream, and the burnt regenerated catalyst 113 is recycled to the top of the first moving bed reactor 11. The mixed product flow 151 enters the three-phase separator 15 to be separated into a water phase, an oil phase and a gas phase, wherein the water phase product flow 153 flows out to be recovered as sewage; the oil phase product stream 191 is separated via dearomatization column 19, upper C₅C₆Fraction stream 192, partially as C₅C₆Product stream 195, remainder as C₅C₆Return hydrocarbon stream 194 is mixed with oxygenate feed 10; the bottom of the dearomatization tower 19 contains an aromatic hydrocarbon material flow 193, part of the aromatic hydrocarbon material flow is used as a product aromatic hydrocarbon material flow 197, and the rest aromatic hydrocarbon material flow 196 is used as a catalyst lifting medium of a lifter 21 to contact with a carbon deposition catalyst to activate the catalyst; the gas phase product stream 152 at the outlet of the three-phase separator 15 is boosted by a compressor 16 to obtain a boosted pressure stream 171, the boosted pressure stream enters a deethanizer 17 for separation, and the top stream C flows out₂Fuel gas stream 172, partly as fuel gas product 173 and the remainder as C₂Return hydrocarbon stream 174 is mixed with oxygenate feed 10; the bottom stream 181 of the deethanizer 17 enters C₄The separation column 18, the overhead propylene-rich product stream 183 enters a propylene separation system, the bottom C₄Stream 182 is partially designated as C₄Product stream 185 with the remainder as C₄The return hydrocarbon stream 184 is mixed with the oxygenate feed 10.

The process of the invention, when n is 3, is carried out in a reactor comprising three moving beds and two catalyst lifters.

A methanol conversion method of a cascade moving bed comprises a reaction process carried out in a first moving bed reactor, a second moving bed reactor and a third moving bed reactor and a process of activating catalysts in a first catalyst lifter and a second catalyst lifter:

introducing a first part of a mixed material of an oxygen-containing compound raw material containing methanol and returned hydrocarbon into a first moving bed reactor to perform contact reaction with a regenerated catalyst to generate a first product flow rich in propylene; the catalyst with carbon deposit flows out of the bottom of the first moving bed reactor, and the aromatic hydrocarbon material flow and the catalyst with carbon deposit contact in the first catalyst lifter and are lifted to the top of the second moving bed reactor to generate a first aromatic hydrocarbon mixture material flow and an activated catalyst;

introducing the oxygen-containing compound raw material containing methanol and a second part in the mixed flow of the returned hydrocarbon into a second moving bed reactor to perform contact reaction with the activated catalyst to generate a second product flow rich in propylene; the activated catalyst with carbon deposit flows out of the bottom of the second moving bed reactor, and the aromatic hydrocarbon-containing material flow and the catalyst with carbon deposit are contacted in the second catalyst lifter and lifted to the top of the third moving bed reactor to generate a second aromatic hydrocarbon-mixed material flow and the activated catalyst;

introducing the oxygen-containing compound raw material containing methanol and a third part of the mixed material flow of the returned hydrocarbon into a third moving bed reactor to perform contact reaction with the activated catalyst to generate a third product flow rich in propylene; the carbon-deposited activated catalyst flows out of the bottom of the third moving bed reactor, enters a regenerator and is burnt and regenerated to obtain the regenerated catalyst, and the regenerated catalyst is circulated back to the first moving bed reactor;

sending the first, second and third product flows rich in propylene and the first and second aromatic mixture flows into a three-phase separator for separation, wherein a water phase is recovered as a sewage flow, an oil phase enters a dearomatization tower for separation, and a gas phase enters a deethanization tower;

c at the top of the dearomatization tower₅And C₆The hydrocarbon stream is partly used as product and the remainder as saidA portion of the returned hydrocarbons of (1); part of aromatic hydrocarbon-containing material flow at the bottom of the dearomatization tower is taken as a product, and the rest part of the aromatic hydrocarbon-containing material flow is taken as a part of the aromatic hydrocarbon-containing material flow;

Fig. 2 is a schematic diagram of a methanol to propylene process with three cascaded moving bed reactors according to the present invention, illustrating the process of the present invention including reaction processes performed in the first, second, and third moving bed reactors and a process of activating the catalyst in the first and second catalyst risers. In order to simplify the description of the invention, the figures do not include illustrations of heaters, heat exchangers, coolers, valves, control devices, and conventional devices known to those skilled in the art, except for the equipment necessary to understand the invention.

In FIG. 2, preheated oxygenate feed 10 is mixed with return hydrocarbons from three streams of the process' subsequent separation system, including C from deethanizer 17₂Stream 174, from the decarbonation₄C of column 18₄Stream 184 and C from dearomatization column 19₅C₆And a material flow 194, after the mixed feeding is obtained and heated, a part of material flow 111 of the mixed feeding enters the first moving bed reactor 11 to contact with a small ball catalyst containing a shape-selective molecular sieve, oxygen-containing compounds are converted into a first product flow 112 rich in propylene and flows out of the top of the first moving bed reactor 11, a regenerated small ball catalyst material 113 enters from the top of the first moving bed reactor 11, the surface of the small ball catalyst material is coked after contacting with the feeding material flow 111, the first product flow flows out of the bottom of the reactor 11 to form a carbon-deposited catalyst 114, the carbon-deposited catalyst 114 is activated by contacting and lifting the carbon-deposited catalyst in a catalyst lifter 21 through an aromatic hydrocarbon-containing material flow 196 flowing out of the dearomatization tower 19The first mixed aromatic product stream 212 at the outlet of the catalyst riser 21 is mixed with the first product stream 112, the activated catalyst stream 123 at the outlet of the catalyst riser 21 enters from the top of the second moving bed reactor 12, contacts and reacts with another part stream 121 of the mixed feed to convert the oxygen-containing compounds into a second product stream 122 rich in propylene and exits from the top of the second moving bed reactor 12, the second product stream 122 is mixed with the first product stream 112 and the first mixed aromatic product stream 212, the carbon-deposited catalyst 124 exits from the bottom of the second moving bed reactor, the carbon-deposited catalyst 124 contacts and lifts in the second catalyst riser 22 via the aromatic-containing stream 198 exiting from the dearomatization tower 19, the second mixed aromatic product stream 222 at the outlet of the riser 22 is mixed with the first product stream 112, the first mixed aromatic product stream 212 and the second product stream 122, the activated catalyst stream 133 at the outlet of the second riser 22 enters from the top of the third moving bed reactor 13, the other part of the feed stream 131 separated from the mixed feed reacts in a contact manner, so that the oxygen-containing compounds are converted into a third product stream 132 rich in propylene, the third product stream 132 flows out from the top of the third moving bed reactor 13, the third product stream 132 is mixed with the first product stream 112, the first mixed aromatic product stream 212, the second product stream 122 and the second mixed aromatic product stream 222 to form a mixed product stream 151, the coked catalyst 134 flowing out from the bottom of the third moving bed reactor enters a regenerator 23 to be burnt in a contact manner with the oxygen-containing gas stream, and the burnt regenerated catalyst stream 113 is recycled to the top of the first moving bed reactor 11; the mixed product stream 151 enters the three-phase separator 15 to be separated into a water phase, an oil phase and a gas phase; wherein the water phase product stream 153 is recovered as sewage, the oil phase product stream 191 is separated by dearomatization column 19, the upper part C₅C₆Fraction stream 192, partially as C₅C₆Product stream 195, remainder as C₅C₆Return hydrocarbon stream 194 is mixed with oxygenate feed 10; the bottom of the dearomatization tower 19 contains an aromatic hydrocarbon material flow 193, part of the aromatic hydrocarbon material flow is used as a product aromatic hydrocarbon material flow 197, part of the aromatic hydrocarbon material flow 196 is used as a catalyst lifting medium of a first catalyst lifter 21 to contact with the carbon deposit catalyst, and the rest of the aromatic hydrocarbon material flow 198 is used as a catalyst lifting medium of a second catalyst lifter 22 to contact with the carbon deposit catalyst; the vapor product stream 152 at the outlet of the three-phase separator 15 is boosted in pressure via compressor 16 to yield a boostA pressure stream 171 is sent into a deethanizer 17 for separation, and a top stream C is discharged₂Fuel gas stream 172, partly as fuel gas product 173 and the remainder as C₂Return hydrocarbon stream 174 is mixed with oxygenate feed 10; the bottom stream 181 of the deethanizer 17 enters C₄The separation column 18, the overhead propylene-rich product stream 183 enters a propylene separation system, the bottom C₄Stream 182 is partially designated as C₄Product stream 185 with the remainder as C₄The return hydrocarbon stream 184 is mixed with the oxygenate feed 10.

The process of the invention, when n is 4, is carried out in a reactor comprising four moving beds and three catalyst risers.

A methanol conversion method of a cascade moving bed comprises a reaction process carried out in a first, a second, a third and a fourth moving bed reactors and a process of activating catalysts in a first, a second and a third catalyst lifters:

introducing the oxygen-containing compound raw material containing methanol and a third part of the mixed material flow of the returned hydrocarbon into a third moving bed reactor to perform contact reaction with the activated catalyst to generate a third product flow rich in propylene; the activated catalyst with carbon deposit flows out of the bottom of the third moving bed reactor, and the aromatic hydrocarbon-containing material flow and the catalyst with carbon deposit are contacted in a third catalyst lifter and lifted to the top of a fourth moving bed reactor to generate a third aromatic hydrocarbon-mixed material flow and the activated catalyst;

introducing a fourth part of the mixed material flow containing the oxygen-containing compound raw material containing the methanol and the return hydrocarbon into a fourth moving bed reactor to perform contact reaction with the activated catalyst to generate a fourth product flow rich in the propylene; the carbon-deposited activated catalyst flows out of the bottom of the fourth moving bed reactor, enters a regenerator and is burnt and regenerated to obtain the regenerated catalyst, and the regenerated catalyst is circulated back to the first moving bed reactor;

feeding the first, second, third and fourth product streams rich in propylene and the first, second and third aromatic mixture streams into a three-phase separator for separation, wherein a water phase is recovered as a sewage stream, an oil phase is fed into a dearomatization tower for separation, and a gas phase is fed into a deethanization tower;

Fig. 3 is a schematic diagram of a methanol to propylene process with four-stage cascade moving bed reactors of the present invention, illustrating the process of the present invention including the reaction process performed in the first, second, third, and fourth moving bed reactors and the process of activating the catalyst in the first, second, and third catalyst risers. In order to simplify the description of the invention, the figures do not include illustrations of heaters, heat exchangers, coolers, valves, control devices, and conventional devices known to those skilled in the art, except for the equipment necessary to understand the invention.

In FIG. 3, preheated oxygenate feed 10 is mixed with return hydrocarbons from three streams of the process' subsequent separation system, including C from deethanizer 17₂Stream 174, from the decarbonation₄C of column 18₄Stream 184 and C from dearomatization column 19₅C₆Stream 194, after obtaining a mixed feed and heating, a part of stream 111 of the mixed feed enters the first moving bed reactor 11 to contact with the small spherical catalyst containing the shape-selective molecular sieve, the oxygenate is converted into a first product stream 112 rich in propylene and flows out from the top of the reactor 11, the regenerated small spherical catalyst material 113 enters from the top of the first moving bed reactor 11, the surface of the small spherical catalyst material is coked after contacting with the stream 111, the first product stream flows out from the bottom of the first moving bed reactor 11 to form a coked catalyst 114, the coked catalyst 114 is lifted in contact with an aromatic hydrocarbon-containing stream 196 flowing out from the dearomatization tower 19 in the first catalyst lifter 21, the first mixed aromatic product stream 212 at the outlet of the first catalyst lifter 21 is mixed with the first product stream 112, the activated catalyst stream 123 at the outlet of the first catalyst lifter 21 enters from the top of the second moving bed reactor 12 to contact with another part of the feed stream 121 separated from the mixed feed, a second product stream 122 for converting the oxygen-containing compounds into the propylene-rich product flows out from the top of the second moving bed reactor 12, the second product stream 122 is mixed with the first product stream 112 and the first mixed aromatic product stream 212, the carbon-deposited catalyst stream 124 flowing out from the bottom of the second moving bed reactor is in contact with and activated to lift in the second catalyst lifter 22 through the aromatic-containing stream 198 flowing out from the dearomatization tower 19, the second mixed aromatic product stream 222 at the outlet of the second catalyst lifter 22 is mixed with the first product stream 112, the first mixed aromatic product stream 212 and the second product stream 122, the activated catalyst stream 133 at the outlet of the second catalyst lifter 22 enters from the top of the third moving bed reactor 13 and is in contact with the other part of the feed stream 131 separated from the mixed feed to react, and the oxygen-containing compounds are converted into the propylene-rich third productStream 132 exits the top of reactor 13, this third product stream 132 is mixed with first product stream 112, first mixed aromatics product stream 212, second product stream 122 and second mixed aromatics product stream 222, the coked catalyst 134 exiting the bottom of the third moving bed reactor is actively lifted by contact with aromatic-containing stream 199 exiting dearomatization column 19 in third catalyst riser 23, third mixed aromatics product stream 232 exiting third catalyst riser 23 is mixed with first product stream 112, first mixed aromatics product stream 212, second product stream 122, second mixed aromatics product stream 222 and third product stream 132, the active catalyst 143 exiting third catalyst riser 23 enters the top of fourth moving bed reactor 14, reacts by contact with another portion of feed stream 141 from which the mixed feed is split, and the oxygenate is converted to propylene-rich fourth product stream 142 exiting the top of fourth moving bed reactor 14, the fourth product stream 142 is mixed with the first product stream 112, the first mixed aromatic product stream 212, the second product stream 122, the second mixed aromatic product stream 222, the third product stream 132 and the third mixed aromatic product stream 232 to form a mixed product stream 151, the coked catalyst 144 flowing out from the bottom of the fourth moving bed reactor enters the regenerator 23 to contact with the oxygen-containing gas stream for burning, and the burnt regenerated catalyst 113 is recycled to the top of the first moving bed reactor 11; the mixed product flow 151 enters the three-phase separator 15 to be separated into a water phase, an oil phase and a gas phase, wherein the water phase product flow 153 flows out to be recovered as sewage; oil phase product stream 191 is separated via dearomatization column 19, top C₅C₆Fraction stream 192, partially as C₅C₆Product stream 195, remainder as C₅C₆Return hydrocarbon stream 194 is mixed with oxygenate feed 10; the bottom of the dearomatization tower 19 contains an aromatic hydrocarbon stream 193, part of the aromatic hydrocarbon stream is used as a product aromatic hydrocarbon stream 197, part of the aromatic hydrocarbon stream 196 is used as a catalyst lifting medium of the first catalyst lifter 21 to contact with the carbon deposit catalyst, part of the aromatic hydrocarbon stream 198 is used as a catalyst lifting medium of the second catalyst lifter 22 to contact with the carbon deposit catalyst, and the rest of the aromatic hydrocarbon stream 199 is used as a catalyst lifting medium of the third catalyst lifter 23 to contact with the carbon deposit catalyst; the gas phase product stream 152 at the outlet of the three-phase separator 15 is boosted in pressure by a compressor 16 to obtain a boosted pressure stream 171, which is sent to a deethanizer 17 for separationFrom the top of the column₂Fuel gas stream 172, partly as fuel gas product 173 and the remainder as C₂Return hydrocarbon stream 174 is mixed with oxygenate feed 10; the bottom stream 181 of the deethanizer 17 enters C₄The separation column 18, the overhead propylene-rich product stream 183 enters a propylene separation system, the bottom C₄Stream 182 is partially designated as C₄Product stream 185 with the remainder as C₄The return hydrocarbon stream 184 is mixed with the oxygenate feed 10.

The process of the present invention is further illustrated by the following examples, which are not intended to be limiting.

Comparative example

This comparative example illustrates the results of an experiment simulating a moving bed reactor on a small atmospheric fixed bed microreaction device to carry out the reaction of methanol to propylene.

The atmospheric fixed bed micro-reverse evaluation device consists of a sample introduction system, a reactor, a product collection system and a temperature control system. The loading amount of a catalyst in the reactor is 5 g, the catalyst is swept to the reaction temperature by high-purity nitrogen when preheating and heating are carried out in reaction evaluation, a methanol raw material is injected into the reactor by a micro-metering pump, a product at the outlet of the reactor is cooled and then separated from a gas-liquid product, the gas-phase product is metered by a wet flowmeter and subjected to chromatographic analysis, and the liquid-phase product is collected and then subjected to chromatographic analysis; and after the evaluation reaction is finished, purging the reactor to reduce the temperature, discharging the carbon deposited catalyst, and roasting and regenerating the carbon deposited catalyst in a muffle furnace. The methanol used was analytical grade. And when the simulation lifter is operated and treated, the methanol raw material is changed into the raw material containing aromatic hydrocarbon to be fed to react with the carbon deposition catalyst, and after the reaction is finished, the methanol raw material is switched back to carry out the reaction of preparing propylene from methanol. The running time and actual methanol throughput (g methanol/g catalyst) were counted in stages and the average propylene/ethylene (P/E) mass ratio and propylene carbon based yield were calculated.

The conversion of methanol was calculated according to formula (1) and the yield of propylene on carbon basis was calculated according to formula (2):

methanol conversion rate (mass of methanol fed-mass of methanol in product)/mass of methanol fed x 100% … … (1)

Propylene carbon-based yield ═ mass of carbon in propylene/mass of carbon in feed methanol × 100% … … … (2)

The MTP catalyst is a ZSM-5 molecular sieve catalyst (containing 80% of a commercial brand ZRP-5 molecular sieve produced by Jian Chang petrochemical Co., Ltd. in Hunan, the balance is silicon oxide, and a rolling forming method is adopted to form 1-1.2 mm small balls by taking silica sol as a binder). Sieving catalyst with 20-40 mesh sieve at 480 deg.C under normal pressure for 2 hr at 100% steam feeding mass space velocity^-1The next treatment is carried out for 12 h.

The MTP reaction of the first moving bed is simulated, the test is evaluated, the reaction pressure is normal pressure, and the tube core temperature of the MTP reactor is controlled to be 480 +/-5 ℃. According to the methanol feeding mass airspeed of 1h^-1And accumulating the operation for 144h, reducing the conversion rate of the methanol from the initial 100 percent to 95.03 percent, and stopping the operation. The MTP catalyst is considered to be carbon-deposited and deactivated, and should be moved out of the moving bed reactor for coke burning regeneration. The methanol handling capacity of 138 g of methanol/g of catalyst, the average propylene/ethylene (P/E) mass ratio of 7.76 and the propylene carbon-based yield of 39.54 percent.

Example 1

This example illustrates the results of a small atmospheric fixed bed microreaction device simulated two moving bed reactors in a methanol to propylene reaction.

The small atmospheric fixed bed micro-reactor and the MTP catalyst used were the same as in comparative example 1. Sieving catalyst with 20-40 mesh sieve at 480 deg.C under normal pressure for 2 hr at 100% steam feeding mass space velocity^-1The next treatment is carried out for 12 h.

The MTP reaction of the first moving bed is simulated, the test is evaluated, the reaction pressure is normal pressure, and the tube core temperature of the MTP reactor is controlled to be 480 +/-5 ℃. According to the methanol feeding mass space velocity of 0.96h^-1And accumulating the operation for 144h, reducing the conversion rate of the methanol from the initial 100 percent to 95.03 percent, and stopping the operation. The MTP catalyst is considered to have been deactivated by carbon deposition and should be removed from the moving bed reactor. The methanol handling capacity of 138 g of methanol/g of catalyst, the average propylene/ethylene (P/E) mass ratio of 7.76 and the propylene carbon-based yield of 39.54 percent.

Simulating the reaction of a catalyst lifter, simulating aromatic hydrocarbon-containing materials by using methylbenzene (analytically pure, Tianjin Kemiou chemical reagent Co., Ltd.) to perform an evaluation test, wherein the reaction pressure is normal pressure, and the tube core temperature of the MTP reactor is controlled to be 470 +/-5 ℃. Switching to toluene feeding mass space velocity of 1h^-1The operation was stopped after 14 hours of cumulative operation.

And (3) simulating a second moving bed MTP reaction evaluation test, wherein the reaction pressure is normal pressure, and the tube core temperature of the MTP reactor is controlled to be 480 +/-5 ℃. According to the methanol feeding mass space velocity of 0.91h^-1And accumulating the operation for 96h, reducing the conversion rate of the methanol from the initial 100 percent to 94.53 percent, and stopping the operation. The MTP catalyst is considered to be carbon-deposited and deactivated, and is moved out of the moving bed reactor to be sent to coke burning regeneration. The methanol handling capacity is 87 g methanol/g catalyst, the average P/E mass ratio is 9.37, and the propylene carbon base yield is 42.34%. The reaction of two continuous simulated moving beds is summed, the methanol handling capacity is 225 g methanol/g catalyst, the average P/E mass ratio is 8.38, and the propylene carbon-based yield is 40.62%.

Example 2

This example illustrates the results of a simulation of three moving bed reactors on a small atmospheric fixed bed microreaction apparatus for the methanol to propylene reaction.

The evaluation of example 1 is followed, the catalyst lifter reaction is simulated, the aromatic hydrocarbon-containing material is simulated by toluene for evaluation test, the reaction pressure is normal pressure, and the tube core temperature of the MTP reactor is controlled at 475 +/-5 ℃. Switching to toluene feeding mass space velocity of 0.5h^-1The operation was stopped after 16 hours of cumulative operation.

And (3) simulating a third moving bed MTP reaction evaluation test, wherein the reaction pressure is normal pressure, and the tube core temperature of the MTP reactor is controlled to be 480 +/-5 ℃. According to the methanol feeding mass space velocity of 0.85h^-1And the operation is accumulated for 82 hours, the conversion rate of the methanol is reduced from the initial 100 percent to 93.54 percent, and the operation is stopped. The MTP catalyst is considered to be carbon-deposited and deactivated, and is moved out of the moving bed reactor to be sent to coke burning regeneration. The methanol handling capacity is 70 g methanol/g catalyst, the average P/E mass ratio is 9.33, and the propylene carbon base yield is 42.55%.

The total of three continuous simulated moving bed reactions, the methanol treatment capacity of 295 g methanol/g catalyst, the average P/E mass ratio of 8.61 and the propylene carbon-based yield of 41.08 percent.

Example 3

This example illustrates the results of an experiment simulating four moving bed reactors in a small atmospheric fixed bed microreaction device to perform a methanol to propylene reaction.

Following the evaluation of example 2, a catalyst riser reaction was simulated. Gasoline (evaluated and retained by MTG in a laboratory and containing 33.9 wt% of aromatic hydrocarbon, 12.69 wt% of olefin and other alkanes and cyclanes) obtained by a methanol-to-gasoline (MTG) process is used as a reactivator, the bed temperature of the MTP catalyst is controlled to be 470 +/-5 ℃, the space velocity is 0.5h < -1 >, and the reaction is carried out for 16h under normal pressure.

And (3) simulating a fourth moving bed MTP reaction evaluation test, wherein the reaction pressure is normal pressure, and the tube core temperature of the MTP reactor is controlled to be 480 +/-5 ℃. According to the methanol feeding mass space velocity of 0.8h^-1And the operation is carried out for 72 hours in a cumulative way, the conversion rate of the methanol is reduced from the initial 100 percent to 93.4 percent, and the operation is stopped. The MTP catalyst is considered to be carbon-deposited and deactivated, and is moved out of the moving bed reactor to be sent to coke burning regeneration. The methanol handling capacity is 58 g methanol/g catalyst, the average P/E mass ratio is 9.1, and the propylene carbon base yield is 42.12%.

The total of four continuous simulated moving bed reactions, the methanol handling capacity of 353 g methanol/g catalyst, the average P/E mass ratio of 8.69 and the propylene carbon-based yield of 41.25 percent.

Example 4

This example illustrates the results of a methanol to propylene experiment conducted on two moving beds in a medium duty unit operated in continuous reaction regeneration.

The pellets of the same composition as in example 1 were used as the catalyst, and the pellets were sieved to obtain particles of 1.6 to 1.8 mm. The first moving bed reactor for preparing propylene from methanol has inlet temperature of 450 deg.C, reaction pressure of 0.15MPa and oxygen-containing compound feeding mass space velocity of 1.0h^-1，C₂-、C₄Hydrocarbons, C₅C₆The mass ratio of total hydrocarbon return to oxygenate feed was 0.9 and the residence time of the catalyst in the reactor was 100 h.

The operation conditions of the riser are as follows, the reaction temperature is 460 ℃, the reaction pressure is 0.17MPa, and the mass space velocity of the fraction containing aromatic hydrocarbon is 0.5h^-1And the contact time is 8 h.

The second moving bed reactor for preparing propylene from methanol has inlet temperature of 455 ℃, reaction pressure of 0.15MPa and mass airspeed of oxygen-containing compound feeding of 0.9h^-1，C₂-、C₄Hydrocarbons, C₅C₆The mass ratio of total hydrocarbon return to oxygenate feed was 0.9,the residence time of the catalyst in the reactor was 80 h.

The regenerator was operated at a mixed nitrogen inlet temperature of 435 ℃ with an oxygen content of 3% by volume, a regeneration pressure of 0.4MPa and a mixed nitrogen feed GHSV of 1000h^-1。

Collecting the product from the apparatus, analyzing the methanol content in the water phase, calculating to obtain a methanol conversion of 99.6%, and obtaining a hydrocarbon product yield percentage content of propylene 73.55%, liquefied gas of 8.23%, and C on a dry basis₅+ gasoline 15.4%, C₂2.82% of fuel gas.

Example 5

This example illustrates the results of a methanol to propylene experiment conducted on three moving beds in a medium-sized unit operated for continuous reaction regeneration.

The pellets of the same composition as in example 1 were used as the catalyst, and the pellets were sieved to obtain particles of 1.6 to 1.8 mm. The first moving bed reactor for preparing propylene from methanol has inlet temperature of 450 deg.C, reaction pressure of 0.13MPa and oxygen-containing compound feeding mass space velocity of 1.0h^-1，C₂-、C₄Hydrocarbons, C₅C₆The mass ratio of total hydrocarbon return to oxygenate feed was 0.9 and the residence time of the catalyst in the reactor was 96 h.

The operating conditions of the first riser are as follows, the reaction temperature is 460 ℃, the reaction pressure is 0.16MPa, and the mass space velocity of the fraction containing aromatic hydrocarbon is 0.5h^-1And the contact time is 8 h.

The second moving bed reactor for preparing propylene from methanol has inlet temperature of 455 ℃, reaction pressure of 0.13MPa and mass airspeed of oxygen-containing compound feeding of 0.9h^-1，C₂-、C₄Hydrocarbons, C₅C₆The mass ratio of total hydrocarbon return to oxygenate feed was 0.9 and the residence time of the catalyst in the reactor was 72 h.

The operating conditions of the second riser are as follows, the reaction temperature is 460 ℃, the reaction pressure is 0.16MPa, and the mass space velocity of the fraction containing aromatic hydrocarbon is 1.0h^-1Contact time 4 h.

The third moving bed reactor for preparing propylene from methanol has the inlet temperature of 460 ℃, the reaction pressure of 0.13MPa and the mass airspeed of oxygen-containing compound feeding of 0.85h^-1，C₂-、C₄Hydrocarbons, C₅C₆The mass ratio of total hydrocarbon return to oxygenate feed was 0.9 and the residence time of the catalyst in the reactor was 48 h.

Collecting the product from the apparatus, analyzing the methanol content in the water phase, calculating to obtain a methanol conversion rate of 99.7%, and obtaining the hydrocarbon product yield percentage content of 74.45% propylene, 8.53% liquefied gas and C on a dry basis₅+ gasoline 13.8%, C₂3.22% of fuel gas.

Example 6

This example illustrates the results of a methanol to propylene experiment conducted on four moving beds in a medium duty unit operated in continuous reaction regeneration.

The pellets of the same composition as in example 1 were used as the catalyst, and the pellets were sieved to obtain particles of 1.6 to 1.8 mm. The first moving bed reactor for preparing propylene from methanol has inlet temperature of 455 deg.C, reaction pressure of 0.18MPa and oxygen-containing compound feeding mass space velocity of 1.0h^-1，C₂-、C₄Hydrocarbons, C₅C₆The mass ratio of total hydrocarbon return to oxygenate feed was 1.2 and the residence time of the catalyst in the reactor was 72 h.

The operation conditions of the riser are as follows, the reaction temperature is 470 ℃, the reaction pressure is 0.2MPa, and the mass space velocity of the fraction containing aromatic hydrocarbon is 0.5h^-1And the contact time is 16 h.

The second moving bed reactor for preparing propylene from methanol has inlet temperature of 458 ℃, reaction pressure of 0.18MPa and mass space velocity of oxygen-containing compound feeding of 0.9h^-1，C₂-、C₄Hydrocarbons, C₅C₆The mass ratio of total hydrocarbon return to oxygenate feed was 1.2 and the residence time of the catalyst in the reactor was 60 h.

The operating conditions of the second riser are as follows, the reaction temperature is 460 ℃, the reaction pressure is 0.22MPa, and the mass space velocity of the fraction containing aromatic hydrocarbon is 1.0h^-1And the contact time is 8 h.

The third moving bed reactor for preparing propylene from methanol has the inlet temperature of 460 ℃, the reaction pressure of 0.18MPa and the mass airspeed of oxygen-containing compound feeding of 0.85h^-1，C₂-、C₄Hydrocarbons, C₅C₆The mass ratio of total hydrocarbon return to oxygenate feed was 1.2 and the residence time of the catalyst in the reactor was 48 h.

The third riser has the following operating conditions that the reaction temperature is 470 ℃, the reaction pressure is 0.2MPa, and the mass space velocity of the aromatic hydrocarbon-containing fraction is 1.5h^-1And the contact time is 6 h.

The fourth moving bed reactor for preparing propylene from methanol has the inlet temperature of 460 ℃, the reaction pressure of 0.18MPa and the mass space velocity of oxygen-containing compound feeding of 0.85h^-1，C₂-、C₄Hydrocarbons, C₅C₆The mass ratio of total hydrocarbon return to oxygenate feed was 1.2 and the residence time of the catalyst in the reactor was 36 h.

The regenerator was operated at a mixed nitrogen inlet temperature of 445 deg.C with an oxygen content of 3% by volume, a regeneration pressure of 0.4MPa, and a mixed nitrogen feed GHSV of 1500h^-1。

Collecting the product from the apparatus, analyzing the methanol content in the water phase, calculating to obtain a methanol conversion rate of 99.8%, and obtaining the hydrocarbon product yield percentage content of propylene 71.25%, liquefied gas 8.43%, and C on a dry basis₅+ gasoline 17.2%, C₂3.12% of fuel gas.

Claims

1. A methanol conversion method of a cascade moving bed comprises a reaction process in n moving bed reactors and a process of activating catalysts in n-1 catalyst lifters, wherein n is more than or equal to 2;

dividing a mixed material of an oxygen-containing compound raw material containing methanol and return hydrocarbon into n parts, wherein the first part is introduced into a first moving bed reactor to be in contact reaction with a regenerated catalyst to generate a first product flow rich in propylene; the carbon-deposited catalyst flows out of the bottom of the first moving bed reactor; contacting a reactivator containing aromatic hydrocarbon material flow with a catalyst of carbon deposit in a first catalyst lifter and lifting the reactivator and the catalyst to the top of a second moving bed reactor to generate a first aromatic hydrocarbon mixed material flow and an activated catalyst;

introducing a second part of the mixture of the oxygen-containing compound raw material containing methanol and the returned hydrocarbon which is divided into n parts into a second moving bed reactor to carry out contact reaction with an activated catalyst to generate a second product flow rich in propylene; the carbon-deposited activated catalyst flows out of the bottom of the second moving bed reactor; the reactivating agent containing aromatic hydrocarbon material flow is contacted with the activated catalyst of carbon deposit in a second catalyst lifter and lifted to the top of a second moving bed reactor to generate a second aromatic hydrocarbon mixed material flow and the activated catalyst;

part of the tower top material flow of the deethanizer is used as fuel gas products, and the rest isThe lower portion being a portion of said returned hydrocarbons; the tower bottom material flow of the deethanizer enters into the de-C₄A tower;

2. A methanol conversion method of a cascade moving bed comprises a reaction process carried out in a first moving bed reactor and a second moving bed reactor and a process of activating a catalyst in a catalyst lifter:

c at the top of the dearomatization tower₅And C₆The hydrocarbon stream is partially used as a product and the remaining portion is used as a part of the returned hydrocarbons; part of aromatic hydrocarbon-containing material flow at the bottom of the dearomatization tower is taken as a product, and the rest part is taken as a productAs part of said aromatic-containing stream;

3. A methanol conversion method of a cascade moving bed comprises a reaction process carried out in a first moving bed reactor, a second moving bed reactor and a third moving bed reactor and a process of activating catalysts in a first catalyst lifter and a second catalyst lifter:

4. A methanol conversion method of a cascade moving bed comprises a reaction process carried out in a first, a second, a third and a fourth moving bed reactors and a process of activating catalysts in a first, a second and a third catalyst lifters:

5. The process of any one of claims 1 to 4 wherein the catalyst is a shape selective molecular sieve pellet catalyst.

6. The process of claim 5, wherein the shape selective molecular sieve is a porous crystalline material of the molecular sieve type having a pore size larger than the critical diameter of the aromatic compound.

7. The process of claim 6 wherein said shape selective molecular sieve is selected from one or more of ZSM-5, ZSM-11, ZSM-12, ZSM-22, ZSM-23, ZSM-35, ZSM-48, MCM-22, IM-5, MOR, Beta, SAPO-11, SAPO-5, and SAPO-31.

8. The process of claim 6 wherein said shape selective molecular sieve is ZSM-5 and/or ZSM-11.

9. The process of claim 5, wherein the selective molecular sieve beads have a diameter of 1.0 to 3.0 mm.

10. The process of claim 9, wherein the shape selective molecular sieve pellet catalyst is prepared by mixing a porous crystalline material of molecular sieve type with various binders or matrix-filling materials, the binders comprise one or more mixtures of silica, alumina, amorphous silica-alumina, titania, zirconia and magnesia, and the matrix-filling materials comprise one or more mixtures of clay, diatomaceous earth, attapulgite and hydrotalcite.

11. The process of claim 1 wherein the aromatic-containing stream contacted with the coked catalyst in the catalyst riser is a hydrocarbon fraction containing not less than 10 wt.% aromatics.

12. The process of claim 11 wherein said aromatic-containing stream is a hydrocarbon fraction having an aromatic content of not less than 20 wt.%.

13. The process of claim 11 wherein the aromatic hydrocarbon is selected from one or more of benzene, toluene, xylene, trimethylbenzene, tetramethylbenzene, ethylbenzene, methylethylbenzene, and tetrahydronaphthalene.

14. The process of claim 11 wherein said hydrocarbon fraction is selected from the group consisting of naphtha reformate, FCC gasoline fraction, coker gasoline fraction, hydrocracked naphtha, coal derived aromatic fraction, methanol aromatization derived fraction.

15. The process of claim 11 wherein said hydrocarbon fraction is C produced in an MTP process₇₊And (6) cutting.

16. A process according to any one of claims 1 to 4 wherein the aromatic hydrocarbon-containing stream is derived entirely from the base of the dearomatization column.