METHOD FOR PRODUCING LOW-CARBON OLEFINS BY CONJUGATION OF METHANOL WITH MIXED HYDROCARBONS

Abstract

Disclosed is a method for preparing low-carbon olefins by coupling methanol with mixed hydrocarbons. The method comprises: introducing gasified methanol and mixed hydrocarbon raw materials into a reaction zone for contact with a catalyst for a reaction to generate stream I containing a product gas and the catalyst; subjecting stream I to gas-solid separation, then the catalyst entering a catalyst residence zone, and the product gas entering a downstream section; and part of the catalyst in the catalyst residence zone entering the reaction region, conveying part of the catalyst to a fluidized bed regenerator for regeneration, and the regenerated catalyst entering a fluidized bed reactor. By means of a fluidized bed reaction-regeneration process, the method achieves continuous preparation of low-carbon olefins by coupling methanol with mixed hydrocarbons. The reaction of preparing the low-carbon olefins from methanol is exothermic, thus providing heat for the catalytic cracking of the mixed hydrocarbons to prepare the low-carbon olefins, achieving self-heat balance. The reaction contact time of the product gas in the reactor is less than 2 s, the carbon-based selectivity for "ethylene + propylene" is greater than or equal to 75% wt, the single-pass conversion rate of methanol is greater than or equal to 99% wt, and the single-pass conversion rate of the mixed hydrocarbons is greater than or equal to 50% wt.

Description

A method for producing light olefins by coupling methanol and mixed hydrocarbons Technical Field

[0001] The present application relates to the field of chemical catalysis technology, and in particular to a method for producing light olefins by coupling methanol and mixed hydrocarbons. Background Art

[0002] Olefins are important basic organic chemical raw materials and the cornerstone of the modern chemical industry. Olefin production technologies primarily include naphtha cracking, methanol to olefins, propane dehydrogenation to propylene, alkane cracking to olefins, and olefin cracking to olefins. Light olefins are highly reactive and prone to reactions such as polymerization, alkylation, and aromatization, generating byproducts that reduce light olefin yields.

[0003] Methanol-to-olefins (MTO) technology targets ethylene and propylene. Methanol is converted over a molecular sieve catalyst into a mixture of ethylene, propylene, butenes, pentenes, and alkanes. The MTO reaction is highly exothermic, typically requiring a heat extractor to remove the heat released by the reaction and charring.

[0004] UOP has developed olefin catalytic cracking (OCP) technology, which converts C4-C8 olefin feedstocks into ethylene and propylene at high temperature and low pressure, with a propylene-to-ethylene ratio of approximately 4:1. The OCP unit consists of two radial flow reactors, one operating online and the other in standby after regeneration. The reactor regeneration cycle is 48 hours. Switching between online and offline regeneration is accomplished using valves located at the reactor inlet and outlet.

[0005] Sinopec has developed olefin catalytic cracking (OCC) technology, which cracks olefins contained in mixed C4-C6 feedstocks into propylene, ethylene, and other products over a molecular sieve catalyst. The OCC unit consists of two fixed-bed reactors, one in operation and one in standby. The reaction system operates using a continuous switching mechanism, and the catalyst regeneration process is controlled by an automatic switching regeneration program.

[0006] Catalytic cracking to produce light olefins is a highly endothermic process. Radial flow reactors and fixed-bed reactors typically use elevated feed temperatures to provide heat. However, excessively high preheat temperatures for feedstock components such as olefins, diolefins, and alkynes can lead to coking, hindering continuous operation. Furthermore, the catalyst gradually loses activity during the reaction, necessitating switching reactors to achieve continuous operation. These heating and deactivation challenges have limited the development and advancement of radial flow and fixed-bed reactor technologies.

[0007] Summary of the Invention

[0008] In view of this, the present application provides a method for producing light olefins by coupling methanol and mixed hydrocarbons, the main purpose of which is to solve the technical problems of low light olefin yield, low mixed hydrocarbon conversion rate and mixed hydrocarbon cracking heat supply.

[0009] Light olefins are highly reactive and prone to polymerization, alkylation, aromatization, and other reactions, generating byproducts that reduce light olefin yield. Reaction contact time is a key factor influencing light olefin selectivity in the catalytic cracking of mixed hydrocarbons to produce light olefins. Increasing the superficial linear velocity in the reaction zone of a fluidized bed reactor can reduce reaction contact time and improve light olefin selectivity. However, this typically results in a significant decrease in bed density and catalyst inventory, leading to a decrease in cracking feedstock conversion. Consequently, there is a negative correlation between light olefin selectivity and feedstock conversion.

[0010] In order to improve the yield of light olefins and the conversion rate of raw materials, the present application provides a high-density fast fluidized bed reactor, which includes a reactor outer shell, a reactor inner shell and a conveying pipe;

[0011] The reactor outer shell is provided with at least a raw material inlet, a catalyst inlet, a gas phase product outlet and a catalyst outlet;

[0012] The reactor outer shell encloses an inner area;

[0013] The inner shell of the reactor is located at the lower part of the internal area, and the area enclosed by the inner shell of the reactor is the reaction zone;

[0014] The delivery pipe is located in the upper middle portion of the inner region, and the bottom of the delivery pipe is connected to the reaction zone;

[0015] The area enclosed by the reactor shell and the delivery pipe is a gas-solid separation area;

[0016] The delivery pipe is provided with an outlet, and the delivery pipe is connected to the gas-solid separation zone;

[0017] The annular area enclosed by the reactor outer shell and the reactor inner shell is the catalyst retention area;

[0018] The bottom of the reaction zone is connected to the bottom of the catalyst retention zone;

[0019] The catalyst retention zone is communicated with the gas-solid separation zone and is located below the gas-solid separation zone.

[0020] Optionally, the high-density fast fluidized bed reactor includes a catalyst distribution pipe, a fluidizing steam distributor, and a raw material distributor;

[0021] The catalyst distribution pipe passes through the inner shell of the reactor and connects the catalyst retention zone and the reaction zone;

[0022] The fluidizing steam distributor is arranged at the bottom of the catalyst retention zone;

[0023] The raw material distributor is arranged at the bottom of the reaction zone.

[0024] Optionally, a through hole is opened on the lower surface of the catalyst distribution tube.

[0025] Optionally, the high-density fast fluidized bed reactor includes a first gas-solid separation device and a second gas-solid separation device;

[0026] The first gas-solid separation equipment and the second gas-solid separation equipment are located in the gas-solid separation zone;

[0027] The inlet of the first gas-solid separation device is connected to the outlet of the conveying pipe;

[0028] The catalyst outlet of the first gas-solid separation device is located at the lower part of the gas-solid separation zone, and the gas outlet of the first gas-solid separation device is located at the upper part of the gas-solid separation zone;

[0029] Preferably, the inlet of the second gas-solid separation device is located at the upper part of the gas-solid separation zone;

[0030] The catalyst outlet of the second gas-solid separation device is located at the lower part of the gas-solid separation zone;

[0031] Optionally, the first gas-solid separation equipment is an inertial separator.

[0032] Optionally, the second gas-solid separation equipment is one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0033] Optionally, the high-density fast fluidized bed reactor includes a reactor gas collecting chamber and a product gas conveying pipe;

[0034] The reactor gas collecting chamber is located at the top of the high-density fast fluidized bed reactor;

[0035] The product gas delivery pipe is connected to the top of the reactor gas collecting chamber;

[0036] The gas outlet of the second gas-solid separation device is communicated with the reactor gas collecting chamber.

[0037] In a second aspect, the present application provides a device for producing light olefins from methanol and mixed hydrocarbons, the device comprising the above-mentioned high-density fast fluidized bed reactor and fluidized bed regenerator;

[0038] A catalyst extraction pipe passes through the outer shell of the reactor and is located at the lower part of the catalyst retention zone, and the catalyst extraction pipe is connected to the reactor stripper;

[0039] The inlet of the spent catalyst slide valve is connected to the bottom of the reactor stripper, the outlet of the spent catalyst slide valve is connected to the inlet of the spent catalyst delivery pipe, and the outlet of the spent catalyst delivery pipe is connected to the fluidized bed regenerator;

[0040] The regenerator stripper is located at the bottom of the fluidized bed regenerator; the inlet of the regeneration slide valve is connected to the bottom of the regenerator stripper, the outlet of the regeneration slide valve is connected to the inlet of the regeneration agent delivery pipe, and the outlet of the regeneration agent delivery pipe is connected to the lower part of the gas-solid separation zone of the high-density fast fluidized bed reactor.

[0041] Optionally, the fluidized bed regenerator includes a regenerator shell, a regenerator distributor, a third gas-solid separation device, a regenerator gas collecting chamber, and a flue gas conveying pipe;

[0042] The regenerator distributor is located at the bottom of the fluidized bed regenerator;

[0043] The third gas-solid separation equipment is located at the upper part of the fluidized bed regenerator, the inlet of the third gas-solid separation equipment is located at the upper part of the fluidized bed regenerator, the gas outlet of the third gas-solid separation equipment is connected to the regenerator gas collecting chamber, the catalyst outlet of the third gas-solid separation equipment is located at the lower part of the fluidized bed regenerator, the regenerator gas collecting chamber is located at the top of the fluidized bed regenerator, and the flue gas conveying pipe is connected to the top of the regenerator gas collecting chamber.

[0044] Optionally, the inlet pipe of the regenerator stripper penetrates the regenerator shell and opens above the regenerator distributor.

[0045] Optionally, the third gas-solid separation equipment adopts one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0046] In a third aspect, the present application provides a method for producing light olefins by coupling methanol and mixed hydrocarbons, which is carried out using the above-mentioned device.

[0047] Optionally, the method for preparing light olefins comprises the following steps:

[0048] The vaporized raw materials including methanol and mixed hydrocarbons are introduced into the reaction zone, contacted with the catalyst, and reacted to generate a product gas containing light olefins and a stream I of the catalyst;

[0049] The stream I is subjected to gas-solid separation to obtain a product gas and a catalyst;

[0050] The product gas is transported to the downstream section;

[0051] A portion of the catalyst enters the reaction zone, and another portion of the catalyst is regenerated, and the regenerated catalyst enters the reaction zone.

[0052] Optionally, the logistics I enters the first gas-solid separation equipment through a conveying pipe, and the catalyst after the first gas-solid separation enters the catalyst retention area.

[0053] Optionally, the mixed hydrocarbons in the feedstock are C4+ hydrocarbons, including alkanes and alkenes with carbon atoms ≥4.

[0054] Optionally, the catalyst is selected from ZSM-5 molecular sieve catalyst.

[0055] Optionally, the process operating conditions of the reaction zone of the high-density fast fluidized bed reactor include:

[0056] The gas superficial velocity is 1.5-7.0 m / s, the temperature is 500-680°C, the pressure is 50-250 kPa, and the bed density is 150-500 kg / m 3 , the reaction contact time is 0.5 to 2s.

[0057] Optionally, the superficial linear velocity of the gas in the reaction zone is selected from any value among 1.5m / s, 2m / s, 2.5m / s, 3m / s, 3.5m / s, 4m / s, 4.5m / s, 5m / s, 5.5m / s, 6m / s, 6.5m / s, 7m / s or any range between two of them.

[0058] Optionally, the temperature of the reaction zone is selected from any value among 500°C, 550°C, 600°C, 650°C, 680°C or any range therebetween.

[0059] Optionally, the pressure of the reaction zone is selected from any value among 50 kPa, 100 kPa, 150 kPa, 200 kPa, 250 kPa, or any range between the two values.

[0060] Optionally, the bed density in the reaction zone is selected from 150 kg / m 3 , 200kg / m 3 , 250kg / m 3 300kg / m 3 、350kg / m 3 , 400kg / m 3 450kg / m 3 , 500kg / m 3 Any value in between or any range of values ​​between them.

[0061] Optionally, the reaction contact time of the reaction zone is selected from any value among 0.5s, 1s, 1.5s, 2s or any range value therebetween.

[0062] Optionally, the process operating conditions of the catalyst residence zone include:

[0063] The gas superficial velocity is 0.02-0.2 m / s, the temperature is 500-680°C, and the bed density is 600-800 kg / m 3 .

[0064] Optionally, the catalyst circulation intensity from the catalyst retention zone to the reaction zone is 500 to 1000 kg / m 2 ·s.

[0065] Optionally, the superficial linear velocity of the gas in the catalyst residence zone is selected from any value among 0.02 m / s, 0.05 m / s, 0.08 m / s, 0.1 m / s, 0.12 m / s, 0.15 m / s, 0.18 m / s, 0.20 m / s or any range between two values.

[0066] Optionally, the temperature of the catalyst residence zone is selected from any value among 500°C, 550°C, 600°C, 650°C, 680°C or any range between them.

[0067] Optionally, the bed density of the catalyst retention zone is 600 kg / m 3 、650kg / m 3 , 700kg / m 3 , 750kg / m 3 , 800kg / m 3 Any value in between or any range of values ​​between them.

[0068] Optionally, the catalyst circulation intensity is selected from any value among 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000 or any range between two values, and the unit is kg / (m 2 ·s).

[0069] Optionally, the process operating conditions of the fluidized bed regenerator are: gas superficial velocity of 0.5-2.0 m / s, regeneration temperature of 600-750°C, regeneration pressure of 50-250 kPa, bed density of 200-800 kg / m 3 .

[0070] Optionally, the superficial linear velocity of the gas in the fluidized bed regenerator is selected from any value among 0.5 m / s, 1 m / s, 1.5 m / s, 2 m / s, or any range between the two values.

[0071] Optionally, the regeneration temperature of the fluidized bed regenerator is selected from any value among 600, 650, 700, 750 or any range between them.

[0072] Optionally, the regeneration pressure of the fluidized bed regenerator is any value among 50 kPa, 100 kPa, 150 kPa, 200 kPa, 250 kPa, or a range between any two values.

[0073] Optionally, the bed density of the fluidized bed regenerator is 200 kg / m 3 , 250kg / m 3 300kg / m 3 、350kg / m 3 , 400kg / m 3 450kg / m 3 , 500kg / m 3 , 550kg / m 3 、600kg / m 3 、650kg / m 3 , 700kg / m 3 , 750kg / m 3 , 800kg / m 3 Any value in between or any range of values ​​between them.

[0074] Optionally, the regeneration gas is air.

[0075] Optionally, steam enters the catalyst retention zone from the fluidized steam distributor, and the steam carries a portion of the catalyst in the catalyst retention zone into the gas-solid separation zone; the product gas in the gas-solid separation zone and a portion of the catalyst carried by the steam enter the second gas-solid separation equipment, and the gas after the second gas-solid separation enters the reactor gas collection chamber, and the separated catalyst returns to the catalyst retention zone.

[0076] Optionally, the product gas and steam after the second gas-solid separation enter the downstream section through the product gas conveying pipe; the first part of the catalyst in the catalyst retention area enters the reaction zone through the catalyst distribution pipe; the second part of the catalyst in the catalyst retention area enters the bottom of the reaction zone through the bottom of the catalyst retention area; the third part of the catalyst in the catalyst retention area enters the reactor stripper through the catalyst extraction pipe.

[0077] The present application provides a specific methanol and mixed hydrocarbon production light olefins device, comprising: a reactor outer shell, a reactor inner shell, a delivery pipe, a raw material distributor, a first gas-solid separation device, a fluidized steam distributor, a catalyst distribution pipe, a second gas-solid separation device, a reactor gas collecting chamber, a product gas delivery pipe, a catalyst extraction pipe, a reactor stripper, a slide valve to be regenerated, and a delivery pipe for the catalyst to be regenerated;

[0078] The area enclosed by the reactor inner shell is the reaction zone, the annular area enclosed by the reactor outer shell and the reactor inner shell is the catalyst retention zone, the bottom of the reaction zone is connected to the bottom of the catalyst retention zone, the area enclosed by the reactor outer shell and the delivery pipe is the gas-solid separation zone, the catalyst retention zone is connected to the gas-solid separation zone and is located below the gas-solid separation zone;

[0079] The raw material distributor is located at the bottom of the reaction zone, the delivery pipe is located in the central area of ​​the upper part of the high-density fast fluidized bed reactor, the bottom end of the delivery pipe is connected to the top of the reaction zone, and the outlet of the delivery pipe is connected to the inlet of the first gas-solid separation device; the first gas-solid separation device is located in the gas-solid separation zone, the catalyst outlet of the first gas-solid separation device is located at the lower part of the gas-solid separation zone, and the gas outlet of the first gas-solid separation device is located at the upper part of the gas-solid separation zone;

[0080] The fluidized steam distributor is located at the bottom of the catalyst retention zone; the catalyst distribution pipe passes through the inner shell of the reactor to connect the catalyst retention zone and the reaction zone, and the lower surface of the catalyst distribution pipe has holes;

[0081] The second gas-solid separation device is located in the gas-solid separation zone, the inlet of the second gas-solid separation device is located in the gas-solid separation zone, the gas outlet of the second gas-solid separation device is connected to the reactor gas collecting chamber, and the catalyst outlet of the second gas-solid separation device is located at the bottom of the gas-solid separation zone; the reactor gas collecting chamber is located at the top of the high-density fast fluidized bed reactor, and the product gas conveying pipe is connected to the top of the reactor gas collecting chamber;

[0082] The catalyst extraction pipe passes through the reactor shell and is located at the lower part of the catalyst retention zone; the reactor stripper is connected to the catalyst extraction pipe, the inlet of the spent catalyst slide valve is connected to the bottom of the reactor stripper, the outlet of the spent catalyst slide valve is connected to the inlet of the spent catalyst delivery pipe, and the outlet of the spent catalyst delivery pipe is connected to the fluidized bed regenerator;

[0083] The first gas-solid separation equipment adopts an inertial separator to achieve rapid separation of product gas and catalyst; the second gas-solid separation equipment adopts one or more groups of gas-solid cyclone separators, each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator;

[0084] The fluidized bed regenerator for regenerating the catalyst comprises: a regenerator shell, a regenerator distributor, a third gas-solid separation device, a regenerator gas collecting chamber, a flue gas conveying pipe, a regenerator stripper, a regeneration slide valve and a regeneration agent conveying pipe;

[0085] The regenerator distributor is located at the bottom of the fluidized bed regenerator; the third gas-solid separation device is located at the upper part of the fluidized bed regenerator, the inlet of the third gas-solid separation device is located at the upper part of the fluidized bed regenerator, the gas outlet of the third gas-solid separation device is connected to the regenerator gas collecting chamber, the catalyst outlet of the third gas-solid separation device is located at the lower part of the fluidized bed regenerator, the regenerator gas collecting chamber is located at the top of the fluidized bed regenerator, and the flue gas conveying pipe is connected to the top of the regenerator gas collecting chamber;

[0086] The regenerator stripper is located outside the regenerator shell, the inlet pipe of the regenerator stripper penetrates the regenerator shell and opens above the regenerator distributor, the inlet of the regeneration slide valve is connected to the bottom of the regenerator stripper, the outlet of the regeneration slide valve is connected to the inlet of the regeneration agent delivery pipe, and the outlet of the regeneration agent delivery pipe is connected to the lower part of the gas-solid separation zone of the high-density fast fluidized bed reactor;

[0087] The third gas-solid separation equipment adopts one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0088] The present application provides a specific method for producing light olefins by coupling methanol and mixed hydrocarbons, comprising:

[0089] a. The catalyst from the regeneration agent delivery pipe enters the gas-solid separation zone of the high-density fast fluidized bed reactor and then enters the catalyst retention zone;

[0090] The gasified raw materials enter the reaction zone from the raw material distributor, contact with the catalyst, and generate product gas containing light olefins. The product gas carries the catalyst through the conveying pipe and enters the first gas-solid separation equipment. After gas-solid separation, the catalyst enters the catalyst retention area; steam enters the catalyst retention area from the fluidized steam distributor, and the steam carries a small amount of catalyst from the catalyst retention area into the gas-solid separation area; the product gas and steam in the gas-solid separation area carry the catalyst and enter the second gas-solid separation equipment. After gas-solid separation, the gas enters the reactor gas collection chamber, and the catalyst returns to the catalyst retention area; the product gas and steam enter the downstream section through the product gas conveying pipe; the catalyst in the catalyst retention area enters the reaction zone through the catalyst distribution pipe; the catalyst in the catalyst retention area enters the bottom of the reaction zone through the bottom of the catalyst retention area; the catalyst in the catalyst retention area enters the reactor stripper through the catalyst extraction pipe. After stripping, the catalyst enters the middle part of the fluidized bed regenerator through the regenerated slide valve and the regenerated agent conveying pipe;

[0091] b. The regeneration gas enters the bottom of the fluidized bed regenerator from the regenerator distributor. In the fluidized bed regenerator, the regeneration gas contacts the catalyst, and the carbon deposits in the catalyst are burned and eliminated. The flue gas generated by the combustion carries the catalyst into the third gas-solid separation device. After gas-solid separation, the flue gas enters the regenerator gas collection chamber and then enters the downstream flue gas treatment system through the flue gas conveying pipe. The catalyst returns to the bottom of the fluidized bed regenerator. The catalyst in the fluidized bed regenerator enters the regenerator stripper. After stripping, it enters the high-density fast fluidized bed reactor through the regeneration slide valve and the regeneration agent conveying pipe.

[0092] The raw materials are methanol and mixed hydrocarbons, preferably, the mixed hydrocarbons are C4+ hydrocarbons, including alkanes and olefins with carbon atoms ≥ 4; the catalyst is a ZSM-5 molecular sieve catalyst;

[0093] The process operating conditions of the reaction zone of the high-density fast fluidized bed reactor are: gas superficial linear velocity of 1.5-7.0 m / s, temperature of 500-680°C, pressure of 50-250 kPa, bed density of 150-500 kg / m 3 , the reaction contact time is 0.5-2s;

[0094] The process operating conditions of the catalyst retention zone are: gas superficial velocity of 0.02-0.2m / s, temperature of 500-680℃, bed density of 600-800kg / m 3 The catalyst circulation intensity of the catalyst retention zone to the reaction zone is 500-1000kg / (m 2 ·s); the regeneration gas is air;

[0095] The process operating conditions of the fluidized bed regenerator are: gas superficial velocity of 0.5-2.0 m / s, regeneration temperature of 600-750 ° C, regeneration pressure of 50-250 kPa, bed density of 200-800 kg / m 3 .

[0096] The method described in this application has a methanol single-pass conversion rate of ≥99% wt, a mixed hydrocarbon single-pass conversion rate of ≥50% wt, an "ethylene + propylene" carbon-based selectivity of ≥75% wt, and a propylene / ethylene (mass ratio) of ≥3.

[0097] The method described in this application, the calculation method of methanol single-pass conversion rate, mixed hydrocarbon single-pass conversion rate, and "ethylene + propylene" carbon-based selectivity is as follows:

[0098] Methanol single-pass conversion rate = (1-mass flow rate of methanol in product gas / mass flow rate of methanol feed) × 100%

[0099] Mixed hydrocarbon single-pass conversion rate = (1-mass flow rate of C4+ hydrocarbons in product gas / mass flow rate of C4+ hydrocarbon feed) × 100%;

[0100] "Ethylene + propylene" carbon-based selectivity = mass flow rate of "ethylene + propylene" in product gas / (mass flow rate of product gas - mass flow rate of water in product gas - mass flow rate of methanol in product gas - mass flow rate of C4 + hydrocarbons in product gas) × 100%

[0101] Compared with the prior art, this application has the following beneficial effects:

[0102] (1) This application discloses a high-density fast fluidized bed reactor, which mainly comprises a reaction zone, a catalyst retention zone and a gas-solid separation zone. The catalyst circulation intensity flowing from the catalyst retention zone to the reaction zone is as high as 500-1000 kg / (m 2 ·s), thereby increasing the bed density in the reaction zone, achieving high bed density under high superficial velocity conditions, and overcoming the negative correlation between light olefin selectivity and feed conversion rate.

[0103] (2) According to the method described in the present application, the reaction contact time of the product gas in the high-density fast fluidized bed reactor is less than 2s, which effectively improves the carbon-based selectivity of "ethylene + propylene".

[0104] (3) In the method described in the present application, the methanol to light olefins reaction releases heat, which provides heat for the catalytic cracking of C4+ hydrocarbons to light olefins reaction, thus achieving self-heating balance.

[0105] (4) The method described in this application realizes a continuous process of producing light olefins by coupling methanol and mixed hydrocarbons through a fluidized bed reaction-regeneration process. BRIEF DESCRIPTION OF THE DRAWINGS

[0106] FIG1 is a schematic diagram of an apparatus according to an embodiment of the present application.

[0107] The reference numerals in Figure 1 are explained as follows: 1-high-density fast fluidized bed reactor; 1-1 reactor outer shell, 1-2 reactor inner shell, 1-3 conveying pipe, 1-4 raw material distributor, 1-5 first gas-solid separation equipment, 1-6 fluidized steam distributor, 1-7 catalyst distribution pipe, 1-8 reactor heat extractor, 1-9 reactor gas collecting chamber; 1-10 product gas conveying pipe; 1-11 catalyst extraction pipe; 1-12 reactor stripper; 1-13 slide valve to be regenerated; 1-14 regenerated agent conveying pipe; 2-fluidized bed regenerator; 2-1 regenerator shell, 2-2 regenerator distributor, 2-3 third gas-solid separation equipment, 2-4 regenerator gas collecting chamber, 2-5 flue gas conveying pipe, 2-6 regenerator stripper, 2-7 regeneration slide valve, 2-8 regeneration agent conveying pipe. DETAILED DESCRIPTION

[0108] The present application is described in detail below with reference to embodiments, but the present application is not limited to these embodiments.

[0109] Unless otherwise specified, the raw materials and catalysts in the examples of this application were purchased from commercial sources.

[0110] In a specific embodiment, the present application provides an apparatus of an embodiment, a schematic structural diagram of which is shown in FIG1 , and the apparatus comprises a high-density fast fluidized bed reactor (1) and a fluidized bed regenerator (2).

[0111] a. The high-density fast fluidized bed reactor (1) comprises: a reactor outer shell (1-1), a reactor inner shell (1-2), a conveying pipe (1-3), a raw material distributor (1-4), a first gas-solid separation device (1-5), a fluidized steam distributor (1-6), a catalyst distribution pipe (1-7), a second gas-solid separation device (1-8), a reactor gas collecting chamber (1-9), a product gas conveying pipe (1-10), a catalyst extraction pipe (1-11), a reactor stripper (1-12), a slide valve to be regenerated (1-13) and a conveying pipe for a catalyst to be regenerated (1-14); the area enclosed by the reactor inner shell (1-2) is a reaction zone (A), and the area enclosed by the reactor outer shell (1-1) and the reactor inner shell (1-2) is a reaction zone (A). The annular area is the catalyst retention area (B), the bottom of the reaction area (A) and the bottom of the catalyst retention area (B) are connected, the area enclosed by the reactor shell (1-1) and the conveying pipe (1-3) is the gas-solid separation area (C), the catalyst retention area (B) and the gas-solid separation area (C) are connected and located below the gas-solid separation area (C); the raw material distributor (1-4) is located at the bottom of the reaction area (A), the conveying pipe (1-3) is located in the central area of ​​the middle and upper parts of the high-density fast fluidized bed reactor, the bottom end of the conveying pipe (1-3) is connected to the top of the reaction area (A), and the outlet of the conveying pipe (1-3) is connected to the inlet of the first gas-solid separation device (1-5); the first gas-solid separation device (1-5) is located in the gas-solid separation area (C) The catalyst outlet of the first gas-solid separation device (1-5) is located at the lower part of the gas-solid separation zone (C), and the gas outlet of the first gas-solid separation device (1-5) is located at the upper part of the gas-solid separation zone (C); the fluidized steam distributor (1-6) is located at the bottom of the catalyst retention zone (B); the catalyst distribution pipe (1-7) passes through the inner shell (1-2) of the reactor to connect the catalyst retention zone (B) and the reaction zone (A), and the lower surface of the catalyst distribution pipe (1-7) is opened; the second gas-solid separation device (1-8) is located in the gas-solid separation zone (C), the inlet of the second gas-solid separation device (1-8) is located in the gas-solid separation zone (C), the gas outlet of the second gas-solid separation device (1-8) is connected to the reactor gas collecting chamber (1-9), and the second gas-solid separation device (1-8) is connected to the reactor gas collecting chamber (1-9). The catalyst outlet of the preparation (1-8) is located at the lower part of the gas-solid separation zone (C); the reactor gas collecting chamber (1-9) is located at the top of the high-density fast fluidized bed reactor, and the product gas conveying pipe (1-10) is connected to the top of the reactor gas collecting chamber (1-9); the catalyst extraction pipe (1-11) passes through the reactor outer shell (1-1) and is located at the lower part of the catalyst retention zone (B); the reactor stripper (1-12) is connected to the catalyst extraction pipe (1-11), the inlet of the to-be-generated slide valve (1-13) is connected to the bottom of the reactor stripper (1-12), the outlet of the to-be-generated slide valve (1-13) is connected to the inlet of the to-be-generated catalyst conveying pipe (1-14), and the outlet of the to-be-generated catalyst conveying pipe (1-14) is connected to the fluidized bed regenerator (2).

[0112] b. The fluidized bed regenerator (2) comprises: a regenerator shell (2-1), a regenerator distributor (2-2), a third gas-solid separation device (2-3), a regenerator gas collecting chamber (2-4), a flue gas conveying pipe (2-5), a regenerator stripper (2-6), a regeneration slide valve (2-7) and a regeneration agent conveying pipe (2-8); the regenerator distributor (2-2) is located at the bottom of the fluidized bed regenerator (2); the third gas-solid separation device (2-3) is located at the upper part of the fluidized bed regenerator (2), the inlet of the third gas-solid separation device (2-3) is located at the upper part of the fluidized bed regenerator (2), the gas outlet of the third gas-solid separation device (2-3) is connected to the regenerator gas collecting chamber (2-4), and the catalyst outlet of the third gas-solid separation device (2-3) is connected to the catalyst outlet of the third gas-solid separation device (2-3). The inlet of the regenerator stripper (2-6) is located at the lower part of the fluidized bed regenerator (2), the regenerator gas collecting chamber (2-4) is located at the top of the fluidized bed regenerator (2), and the flue gas conveying pipe (2-5) is connected to the top of the regenerator gas collecting chamber (2-4); the regenerator stripper (2-6) is located outside the regenerator shell (2-1), the inlet pipe of the regenerator stripper (2-6) penetrates the regenerator shell (2-1) and opens above the regenerator distributor (2-2), the inlet of the regeneration slide valve (2-7) is connected to the bottom of the regenerator stripper (2-6), the outlet of the regeneration slide valve (2-7) is connected to the inlet of the regeneration agent conveying pipe (2-8), and the outlet of the regeneration agent conveying pipe (2-8) is connected to the lower part of the gas-solid separation zone (C) of the high-density fast fluidized bed reactor (1).

[0113] In a preferred embodiment, the first gas-solid separation device (1-5) uses an inertial separator to achieve rapid separation of the product gas and the catalyst.

[0114] In a preferred embodiment, the second gas-solid separation equipment (1-8) adopts one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0115] In a preferred embodiment, the third gas-solid separation equipment (2-3) adopts one or more groups of gas-solid cyclone separators, and each group of gas-solid cyclone separators includes a first-stage gas-solid cyclone separator and a second-stage gas-solid cyclone separator.

[0116] In a specific embodiment, a method for producing light olefins by coupling methanol and mixed hydrocarbons of the present application comprises the following steps:

[0117] a. The catalyst from the regeneration agent delivery pipe (2-8) enters the gas-solid separation zone (C) of the high-density fast fluidized bed reactor (1) and then enters the catalyst retention zone (B); the gasified raw material enters the reaction zone (A) from the raw material distributor (1-4), contacts with the catalyst, and generates product gas containing light olefins. The product gas carries the catalyst through the delivery pipe (1-3) and enters the first gas-solid separation device (1-5). After gas-solid separation, the catalyst enters the catalyst retention zone (B); steam enters the catalyst retention zone (B) from the fluidized steam distributor (1-6), and the steam carries a small amount of catalyst from the catalyst retention zone (B) into the gas-solid separation zone (C); the product gas and steam in the gas-solid separation zone (C) carry the catalyst into the first gas-solid separation device (1-5). Second gas-solid separation equipment (1-8), after gas-solid separation, the gas enters the reactor gas collecting chamber (1-9), and the catalyst returns to the catalyst retention zone (B); the product gas and steam enter the downstream section through the product gas conveying pipe (1-10); the catalyst in the catalyst retention zone (B) enters the reaction zone (A) through the catalyst distribution pipe (1-7); the catalyst in the catalyst retention zone (B) enters the bottom of the reaction zone (A) through the bottom of the catalyst retention zone (B); the catalyst in the catalyst retention zone (B) enters the reactor stripper (1-12) through the catalyst extraction pipe (1-11), and after stripping, the catalyst enters the middle part of the fluidized bed regenerator (2) through the regeneration slide valve (1-13) and the regeneration agent conveying pipe (1-14);

[0118] b. The regeneration gas enters the bottom of the fluidized bed regenerator (2) from the regenerator distributor (2-2). In the fluidized bed regenerator (2), the regeneration gas contacts the catalyst, and the carbon deposits in the catalyst are burned and eliminated. The flue gas formed by the combustion carries the catalyst into the third gas-solid separation device (2-3). After gas-solid separation, the flue gas enters the regenerator gas collection chamber (2-4) and then enters the downstream flue gas treatment system through the flue gas conveying pipe (2-5). The catalyst returns to the bottom of the fluidized bed regenerator (2). The catalyst in the fluidized bed regenerator (2) enters the regenerator stripper (2-6). After stripping, it enters the high-density fast fluidized bed reactor (1) through the regeneration slide valve (2-7) and the regeneration agent conveying pipe (2-8).

[0119] Example 1

[0120] This embodiment 1 adopts the device shown in Figure 1.

[0121] In Example 1, the raw materials are methanol and C4-C6 hydrocarbons, the methanol feed amount / C4-C6 hydrocarbon feed amount is about 1, the olefin content in the C4-C6 hydrocarbons is 91% by weight, and the alkane content is 9% by weight. The catalyst is a ZSM-5 molecular sieve catalyst.

[0122] The process operating conditions of the reaction zone (A) of the high-density fast fluidized bed reactor (1) are: gas superficial linear velocity of 1.5 m / s, temperature of 500°C, pressure of 250 kPa, bed density of 500 kg / m 3 , the reaction contact time is 2s.

[0123] The process operating conditions of the catalyst retention zone (B) are: gas superficial velocity of 0.10 m / s, temperature of 500 °C, bed density of 670 kg / m 3 The catalyst circulation intensity flowing from the catalyst retention zone (B) to the reaction zone (A) is 500 kg / (m 2 ·s).

[0124] The regeneration gas is air. The process operating conditions of the fluidized bed regenerator (2) are: gas superficial linear velocity of 0.5m / s, regeneration temperature of 600℃, regeneration pressure of 250kPa, bed density of 800kg / m 3 .

[0125] The single-pass conversion rate of methanol is 99% wt, the single-pass conversion rate of mixed hydrocarbons is 79% wt, the "ethylene + propylene" carbon-based selectivity is 87% wt, and the propylene / ethylene (mass ratio) is 3.1.

[0126] Example 2

[0127] This embodiment 2 adopts the device shown in Figure 1.

[0128] In Example 2, the raw materials are methanol and C4-C6 hydrocarbons, the methanol feed amount / C4-C6 hydrocarbon feed amount is about 1, the olefin content in the C4-C6 hydrocarbons is 46% wt, and the alkane content is 54% wt. The catalyst is a ZSM-5 molecular sieve catalyst.

[0129] The process operating conditions of the reaction zone (A) of the high-density fast fluidized bed reactor (1) are: gas superficial linear velocity of 2.6 m / s, temperature of 600°C, pressure of 170 kPa, bed density of 310 kg / m 3 , the reaction contact time is 1.2s.

[0130] The process operating conditions of the catalyst retention zone (B) are: gas superficial velocity of 0.2 m / s, temperature of 600 ° C, bed density of 600 kg / m 3 The catalyst circulation intensity flowing from the catalyst retention zone (B) to the reaction zone (A) is 720 kg / (m 2 ·s).

[0131] The regeneration gas is air. The process operating conditions of the fluidized bed regenerator (2) are: gas superficial linear velocity of 2.0 m / s, regeneration temperature of 650°C, regeneration pressure of 170 kPa, bed density of 200 kg / m 3 .

[0132] The single-pass conversion rate of methanol is 99.8% wt, the single-pass conversion rate of mixed hydrocarbons is 50% wt, the "ethylene + propylene" carbon-based selectivity is 78% wt, and the propylene / ethylene (mass ratio) is 4.4.

[0133] Example 3

[0134] This embodiment 3 adopts the device shown in Figure 1.

[0135] In this embodiment 3, the raw materials are methanol and C5-C 12 Hydrocarbon, methanol feed / C5-C 12 The hydrocarbon feed amount is about 1, C5-C 12 The olefin content in the hydrocarbons is 64% wt, and the alkane content is 36% wt. The catalyst is a ZSM-5 molecular sieve catalyst.

[0136] The process operating conditions of the reaction zone (A) of the high-density fast fluidized bed reactor (1) are: gas superficial linear velocity of 4.1 m / s, temperature of 650°C, pressure of 110 kPa, bed density of 190 kg / m 3 , the reaction contact time is 0.8s.

[0137] The process operating conditions of the catalyst retention zone (B) are: gas superficial velocity of 0.08 m / s, temperature of 650°C, bed density of 720 kg / m 3 The catalyst circulation intensity flowing from the catalyst retention zone (B) to the reaction zone (A) is 810 kg / (m 2 ·s).

[0138] The regeneration gas is air. The process operating conditions of the fluidized bed regenerator (2) are: gas superficial linear velocity of 1.6 m / s, regeneration temperature of 690°C, regeneration pressure of 110 kPa, bed density of 340 kg / m 3 .

[0139] The methanol single-pass conversion rate was 99.9% wt, the mixed hydrocarbon single-pass conversion rate was 77% wt, the "ethylene + propylene" carbon-based selectivity was 81% wt, and the propylene / ethylene (mass ratio) was 7.8.

[0140] Example 4

[0141] This embodiment 4 uses the device shown in Figure 1.

[0142] In this embodiment 4, the raw materials are methanol and C5-C12 Hydrocarbon, methanol feed / C5-C 12 The hydrocarbon feed amount is about 1, C5-C 12 The olefin content in the hydrocarbon is 8% wt, and the alkane content is 92% wt. The catalyst is a ZSM-5 molecular sieve catalyst.

[0143] The process operating conditions of the reaction zone (A) of the high-density fast fluidized bed reactor (1) are: gas superficial linear velocity of 7.0 m / s, temperature of 680°C, pressure of 50 kPa, bed density of 150 kg / m 3 , the reaction contact time is 0.5s.

[0144] The process operating conditions of the catalyst retention zone (B) are: gas superficial velocity of 0.02 m / s, temperature of 680°C, bed density of 800 kg / m 3 The catalyst circulation intensity of the catalyst flowing from the catalyst retention zone (B) to the reaction zone (A) is 1000 kg / (m 2 ·s).

[0145] The regeneration gas is air. The process operating conditions of the fluidized bed regenerator (2) are: gas superficial linear velocity of 0.9 m / s, regeneration temperature of 750°C, regeneration pressure of 50 kPa, bed density of 520 kg / m 3 .

[0146] The methanol single-pass conversion rate was 99.9% wt, the mixed hydrocarbon single-pass conversion rate was 65% wt, the "ethylene + propylene" carbon-based selectivity was 75% wt, and the propylene / ethylene (mass ratio) was 9.3.

[0147] The above descriptions are merely a few embodiments of the present application and do not constitute any form of limitation to the present application. Although the present application discloses the preferred embodiments as above, they are not intended to limit the present application. Any technical personnel familiar with the present profession, without departing from the scope of the technical solution of the present application, using the technical content disclosed above to make slight changes or modifications are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for producing low-carbon olefins by conjugating methanol with mixed hydrocarbons, characterized in that it includes the following stages: feeding gasified feedstock containing methanol and mixed hydrocarbons into the reaction zone for contact with the catalyst and reaction to form stream I containing product gas with low-carbon olefins and catalyst; carrying out gas-solid separation of the said stream I to obtain a product gas and a catalyst; transportation of the specified production gas to the next section; feeding a portion of the catalyst into the reaction zone, regenerating the other portion of the catalyst, and feeding the regenerated catalyst into the said reaction zone.

2. A method for producing low-carbon olefins by conjugating methanol with mixed hydrocarbons according to claim 1, characterized in that the mixed hydrocarbons in said feedstock are C hydrocarbons.4+ , containing alkanes and olefins with a number of carbon atoms ≥4; said catalyst is selected from catalysts based on ZSM-5 molecular sieve; The operating conditions of the specified reaction zone include: apparent linear gas velocity: from 1.5 m / s to 7.0 m / s; temperature: from 500°C to 680°C; pressure: from 50 kPa to 250 kPa; bed density: from 150 kg / m 3 up to 500 kg / m 3 ; reaction contact time: from 0.5 s to 2 s.

3. A method for producing low-carbon olefins by coupling methanol with mixed hydrocarbons according to claim 1, characterized in that said method is carried out in a plant for producing low-carbon olefins from methanol and mixed hydrocarbons, wherein said plant includes a high-density, fast-circulation fluidized bed reactor and a fluidized bed regenerator.

4. A method for producing low-carbon olefins by coupling methanol with mixed hydrocarbons according to claim 3, characterized in that said high-density fluidized bed reactor with rapid circulation includes a reactor body, an inner reactor body, and a transport pipe; on the said reactor body at least a feedstock inlet, a catalyst inlet, a gaseous product outlet and a catalyst outlet are installed; the said reactor vessel defines the internal area; said inner reactor body is located in the lower part of said inner region, the region bounded by said inner reactor body is the reaction zone; said transport pipe is located in the central upper part of said internal region, the bottom of said transport pipe communicates with said reaction zone; the area bounded by the said reactor vessel and the said transport pipe is the gas-solid separation zone; an outlet is installed on the said transport pipe, the said transport pipe communicates with the said gas-solid separation zone; the annular region bounded by said reactor body and said inner reactor body is a catalyst retention zone; the bottom of said reaction zone communicates with the bottom of said catalyst retention zone; said catalyst retention zone communicates with the gas-solid separation zone and is located below said gas-solid separation zone.

5. A method for producing low-carbon olefins by coupling methanol with mixed hydrocarbons according to paragraph 4, characterized in that the operating conditions of said catalyst retention zone include: an apparent linear gas velocity of 0.02-0.2 m / s, a temperature of 500-680°C, and a bed density of 600-800 kg / m3. 3 , the intensity of circulation of the catalyst flowing from the said catalyst retention zone to the said reaction zone is 500-1000 kg / (m 2 ⋅с).

6. A method for producing low-carbon olefins by coupling methanol with mixed hydrocarbons according to claim 4, characterized in that said high-density fluidized bed reactor with rapid circulation includes a catalyst distribution pipe, a fluidizing steam distributor, and a feedstock distributor; said catalyst distribution pipe passes through the inner reactor vessel and connects said catalyst retention zone with said reaction zone; said fluidizing steam distributor is installed in the lower part of said catalyst retention zone; the said raw material distributor is installed in the lower part of the said reaction zone; through holes are made on the lower surface of the said catalytic converter distribution pipe.

7. A method for producing low-carbon olefins by coupling methanol with mixed hydrocarbons according to claim 4, characterized in that said high-density, fast-circulation fluidized bed reactor includes a first gas-solid separation device and a second gas-solid separation device; said first gas-solid separation device and said second gas-solid separation device are located in said gas-solid separation zone; the input of said first gas-solid separation device communicates with the output of said transport pipe; the catalyst outlet of said first gas-solid separation device is located in the lower part of the gas-solid separation zone, the gas outlet of said first gas-solid separation device is located in the upper part of said gas-solid separation zone; the inlet of said second gas-solid separation device is located in the upper part of said gas-solid separation zone; the outlet of the catalyst of said second gas-solid separation device is located in the lower part of said gas-solid separation zone; an inertial separator is used as the said first gas-solid separation device; one or more groups of gas-solid cyclone separators are used as the said second gas-solid separation device, each group of gas-solid cyclone separators includes one first-stage cyclone separator and one second-stage cyclone separator; said high density fast circulation fluidized bed reactor comprises a reactor collection chamber and a product gas transport pipe; the said reactor collection chamber is located in the upper part of the high-density, fast-circulation fluidized bed reactor; the said production gas transportation pipe is connected to the upper part of the reactor collection chamber; the gas outlet of said second gas-solid separation device communicates with said reactor collection chamber.

8. A method for producing low-carbon olefins by coupling methanol with mixed hydrocarbons according to claim 4, characterized in that said installation includes a catalyst collection pipe, wherein said catalyst collection pipe passes through said reactor body and is located in the lower part of the catalyst retention zone, said catalyst collection pipe communicates with the stripping column of the reactor; the inlet of the spent sliding valve is connected to the bottom of the said stripping column of the reactor, the outlet of the said spent sliding valve is connected to the inlet of the spent agent transport pipe, the outlet of the said spent agent transport pipe communicates with the fluidized bed regenerator; the regenerator stripping column is located at the bottom of said fluidized bed regenerator; the inlet of the regenerated sliding valve is connected to the bottom of said regenerator stripping column, the outlet of said regenerated sliding valve is connected to the inlet of the regenerated agent transport pipe, the outlet of the regenerated agent transport pipe is connected to the bottom of the gas-solid separation zone of the high-density, fast-circulation fluidized bed reactor; said fluidized bed regenerator includes a regenerator body, a regenerator distributor, a third gas-solid separation device, a regenerator collection chamber, and a flue gas transportation pipe; said regenerator distributor is located at the bottom of said fluidized bed regenerator; said third gas-solid separation device is located in the upper part of said fluidized bed regenerator, the inlet of said third gas-solid separation device is located in the upper part of said fluidized bed regenerator, the gas outlet of said third gas-solid separation device is connected to said collection chamber of the regenerator, the catalyst outlet of said third gas-solid separation device is located in the lower part of said fluidized bed regenerator, said collection chamber of the regenerator is located in the upper part of said fluidized bed regenerator, said flue gas transport pipe is connected to the upper part of said collection chamber of the regenerator; the inlet pipe of said regenerator stripping column passes through said regenerator body and opens above said regenerator distributor; One or more groups of gas-solid cyclone separators are used as the specified third gas-solid separation device, each group of gas-solid cyclone separators includes one first-stage cyclone separator and one second-stage cyclone separator.

9. A method for producing low-carbon olefins by conjugating methanol with mixed hydrocarbons according to paragraph 4, characterized in that the operating conditions of said regenerator include: the apparent linear velocity of the gas is 0.5-2.0 m / s, the regeneration temperature is 600-750°C, the regeneration pressure is 50-250 kPa and the bed density is 200-800 kg / m3 3 ; the regenerating gas of the said fluidized bed regenerator is air; the said flow I enters the first gas-solid separation device through the transport pipe, the catalyst after the first gas-solid separation enters the catalyst retention zone.

10. The method for producing low-carbon olefins by coupling methanol with mixed hydrocarbons according to claim 4, characterized in that steam from the fluidizing steam distributor enters the catalyst retention zone, the steam carries away a portion of the catalyst from the catalyst retention zone to the gas-solid separation zone; the product gas in the gas-solid separation zone and a portion of the catalyst carried away by the steam enter the second gas-solid separation device, the gas after the second gas-solid separation enters the collecting chamber of the reactor, the separated catalyst returns to the catalyst retention zone; the product gas and steam after the second gas-solid separation enter the subsequent section through a product gas transport pipe; the first portion of the catalyst in the catalyst retention zone enters the reaction zone through the catalyst distribution pipe; the second portion of the catalyst in the catalyst retention zone enters the bottom of the reaction zone through the bottom of the catalyst retention zone;the third part of the catalyst in the catalyst retention zone enters the stripping column of the reactor through the catalyst collection pipe.