Molecular sieve catalyst regeneration scorching process of moving bed light hydrocarbon conversion device

Abstract

The invention discloses a moving bed light hydrocarbon conversion device molecular sieve catalyst regeneration scorching process. The method comprises the following steps: a to-be-regenerated molecular sieve catalyst reacted by a moving bed light hydrocarbon conversion device enters a pre-scorching area for pre-scorching, then sequentially enters a first-section scorching area, a second-section scorching area and an axial scorching area of a regenerator by virtue of gravity for scorching regeneration, and the regenerated catalyst is recycled; a horizontally arranged baffle is arranged between the pre-charring area and the first-section charring area; regeneration gas after being burnt in the axial burning area and regeneration gas after being burnt in the first-section burning area and the second-section burning area are gathered in a space enclosed by a screen in the regenerator, are led out from a regeneration gas outlet of the burning areas, are subjected to heat exchange, cooling, drying or compression, and are divided into two paths, namely two paths and two paths; the first path enters a pre-scorching area to pre-scorch the molecular sieve catalyst to be generated, the scorched regeneration gas and the second path are combined and then are divided into three paths, and the three paths enter a regenerator after being respectively supplemented with air and heated. The method provided by the invention can effectively control the temperature of the catalyst bed, ensure the burning effect of the catalyst and prolong the service life of the catalyst.

Description

Technical Field

[0001] The invention belongs to the field of petrochemical industry and relates to catalyst regeneration and coking, and specifically to a molecular sieve catalyst regeneration and coking process of a moving bed light hydrocarbon conversion device. Background Art

[0002] Light hydrocarbons mainly include C2 to C7 components produced from refineries, among which C2 components are mainly found in dry gas products produced from catalytic cracking, delayed coking and other units, and contain some olefins such as ethylene, which can be used as raw materials for light hydrocarbon conversion to produce aromatics; C3 and C4 components are mainly found in liquefied petroleum gas products produced from refineries, and are the main processing raw materials for existing light hydrocarbon conversion technologies. Moreover, with the development of my country's natural gas industry, the market for urban civilian liquefied gas is gradually shrinking. The use of light hydrocarbon conversion technology to convert this relatively surplus liquefied gas resource into high value-added products has important practical significance and good economic efficiency.

[0003] Light hydrocarbon conversion technology originated in the early 1970s. The catalyst is a modified ZSM-5 molecular sieve catalyst. The catalyst can be used to convert light hydrocarbon components from C2 to C5 into aromatics and produce hydrogen as a by-product. It has the advantages of wide raw material adaptability, high product value, simple process flow, and low construction cost. It has developed rapidly in recent years. Representative technologies include UOP's Cyclar process, MOBIL's M2-Forming process, Japan's SANYO's Alpha process, Japan's Mitsubishi Oil (MITSUBISHI) and Chiyoda Corporation (CHIYODA) jointly developed Z-Forming process, France IFP and Australia SALUTEC jointly developed Aroforming process, etc.

[0004] Most light hydrocarbon conversion units use fixed-bed technology, which is characterized by low investment and quick results, but its disadvantages are also obvious: due to the use of two reactors for switching regeneration, the operation is cumbersome and the investment in catalysts is also large (the fixed bed catalyst capacity is about doubled that of the moving bed); there are also changes in product distribution, especially in the later stage, the dry gas yield in the product increases significantly, and the hydrogen yield produced is unstable, which affects subsequent units.

[0005] The moving bed catalyst regeneration and coking technology realizes the continuous coking and regeneration of the catalyst in the regenerator, so that the average activity of the catalyst is always maintained at a high level, avoiding cumbersome switching operations, maintaining plug flow of catalyst particles, strengthening mass transfer and heat transfer, and improving product yield and quality. Since the hydrogen-containing coke on the surface of the catalyst will generate water vapor during the combustion process, that is, the catalyst coking process is carried out in a high temperature and water-containing environment, the regeneration and coking process of the catalyst is a key link affecting the life of the catalyst. The amount of carbon deposits, coking temperature, and oxygen partial pressure of the catalyst are the main factors affecting the catalyst coking rate. Increasing the coking temperature under the same coking conditions can accelerate the coking rate, but too high a coking temperature will cause the catalyst bed to overheat, the catalyst to sinter, and the equipment to be damaged. The proper coking temperature must be controlled. Under the same coking temperature and gas-agent ratio, appropriately increasing the oxygen partial pressure in the coking medium can also accelerate the coking rate and shorten the coking time. Different oxygen contents can be controlled at different coking stages according to actual conditions.

[0006] In the dry regeneration process provided by USP5,304,117, CN1045411A and CN102869447A, it is mainly aimed at precious metal catalysts, and the regenerator charring zone is a two-stage charring structure. The catalyst bed in the charring zone is divided into two sections, and the catalyst is transported from top to bottom through the material legs. The two sections of the bed have the same structural dimensions and different regeneration gas inlet conditions. The entire charring is mainly concentrated in the upper section of the bed. The inlet temperature of the regeneration gas of the lower section of the bed is higher than that of the upper section of the bed. The regeneration gas inlet of the lower section of the bed is supplemented with air to adjust the oxygen content of the regeneration gas, and the regeneration gas enters from the top and exits from the bottom. A drying system is set in the regeneration gas circulation loop, so the water content of the regeneration circulation gas is low, and the mass flux of the bed gas is large, so the temperature rise of the overall bed is lower than that of single-stage charring. The present invention is mainly aimed at the molecular sieve catalyst of the light hydrocarbon conversion device. The purpose of setting the pre-burning zone is mainly to pre-burn the catalyst carbon powder on the surface and inside of the molecular sieve particles by adjusting the temperature and the regeneration gas flow rate to prevent the burning zone from overheating, causing catalyst caking and equipment damage.

[0007] CN101658799B discloses a continuous catalyst regeneration method, which discloses that the reactor system does not have a spare reactor, and the reactor uses a spherical particle catalyst containing an active molecular sieve. During the reaction, the coke-containing catalyst is continuously removed from the reactor and regenerated in a regenerator. The regenerated regenerator enters the reactor system and continues to participate in the catalytic reaction. After the gas in the regenerator completes the catalyst coke regeneration, it enters the purification system for purification, and is matched with a certain amount of air. After pressurized heat exchange and heating, it enters the regenerator as regeneration gas again; air matching the gas from the regeneration gas purification system is injected from the downstream of the regeneration gas purification system. In this method, the regenerator is coked in one stage and oxygen is injected once, and there is no effective means to control the temperature of the coke bed of the regenerator.

[0008] CN105879927A discloses a moving bed light hydrocarbon to aromatics catalyst regeneration and charring method, which discloses that the charring area is divided into two sections, namely, the upper charring section and the lower charring section. The catalyst charred in the upper charring section and the lower charring section of the charring area enters the drying area under the action of gravity, completing the charring and regeneration process of the molecular sieve catalyst to be regenerated, and the regenerated catalyst is recycled. We have improved and optimized it on this basis, adding a pre-charring area and an axial charring area to further ensure the charring effect of the catalyst. Summary of the invention

[0009] Aiming at the problem that the carbon powder on the surface and inside of the regenerated molecular sieve catalyst of a moving bed light hydrocarbon conversion device is flammable but the core is not easy to burn, resulting in a black core of the catalyst, the present invention provides a regeneration and coking process for the molecular sieve catalyst of a moving bed light hydrocarbon conversion device, so as to solve the problem of uneven distribution of the reaction products of the device due to incomplete burning of the catalyst.

[0010] The present invention provides a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, which is characterized by comprising the following steps:

[0011] 1) The regenerated molecular sieve catalyst after the reaction in the moving bed light hydrocarbon conversion unit enters the pre-burning zone of the regenerator through the catalyst feed leg for pre-burning, and then enters the burning zone of the regenerator by gravity for catalyst burning regeneration, wherein the burning zone is divided into three sections, namely, the first burning zone, the second burning zone and the axial burning zone. The regenerated molecular sieve catalyst entering the burning zone of the regenerator contacts with the oxygen-containing regeneration gas in the first burning zone, the second burning zone and the axial burning zone in turn by gravity to burn the carbon deposits on the catalyst, thus completing the burning regeneration process of the regenerated molecular sieve catalyst. The regenerated catalyst comes out from the bottom of the regenerator and is recycled;

[0012] 2) Inside the regenerator, from top to bottom, there are the pre-burning zone, the first-stage burning zone, the second-stage burning zone and the axial burning zone. A horizontal baffle is arranged between the pre-burning zone and the first-stage burning zone to block the regeneration gas in the pre-burning zone from being mixed with the regeneration gas in other burning zones. The regeneration gas in the first-stage burning zone and the regeneration gas in the second-stage burning zone are circumferentially distributed in the regenerator space surrounded by the outer screen and the regenerator cylinder, and radially and centripetally pass through the catalyst bed and burn the carbon deposits on the catalyst. After the regeneration gas in the axial burning zone burns the residual carbon deposits in the core of the molecular sieve catalyst axially, it is collected with the regeneration gas that has been burned in the first-stage burning zone and the second-stage burning zone in the space surrounded by the screen in the regenerator, and is drawn out from the regeneration gas outlet of the burning zone, and then successively passes through the regeneration gas heat exchanger tube for heat exchange and cooling, the regeneration gas cooler for cooling, the regeneration gas drying system for drying, the regeneration gas inlet pressure regulating tank for pressure stabilization, the regeneration gas circulation compressor for pressure boosting and the regeneration gas After the shell side of the heat exchanger is heated up by heat exchange, it is first divided into two paths as circulating regeneration gas. The first circulating regeneration gas is heated to 420-500℃ by the pre-burning zone heating device, enters the pre-burning zone from the regeneration gas inlet of the pre-burning zone, passes through the catalyst bed centripetally and burns the carbon powder adhering to the surface and inside of the molecular sieve catalyst particles, and is led out from the regeneration gas outlet of the pre-burning zone at the top of the regenerator. The high-temperature regeneration gas after being led out is combined with the second circulating regeneration gas and then divided into three paths. One of them is supplemented with air and heated to 400-480℃ by a first-stage heating device, and enters the first-stage burning zone through the regeneration gas inlet of the first-stage burning zone; the other path is supplemented with air, heated to 410-490℃ by a second-stage heating device, and enters the second-stage burning zone through the regeneration gas inlet of the second-stage burning zone; the last path is supplemented with air and heated to 420-500℃ by the axial burning zone heating device, and enters the axial burning zone from the regeneration gas inlet of the axial burning zone.

[0013] The present invention provides a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, and its further technical feature is that the light hydrocarbon conversion device is preferably a light hydrocarbon aromatization device or a light hydrocarbon to propane device.

[0014] The present invention discloses a molecular sieve catalyst regeneration and burning process for a moving bed light hydrocarbon conversion device, and its further technical features are: the operating pressure of the regenerator is 0.35-1.40MPa, the catalyst bed temperature of the regenerator is 450-600°C, and the catalyst residence time in the regenerator is 6-20h

[0015] The present invention discloses a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, and its further technical feature is that: when the regeneration gas enters the pre-coking zone of the regenerator, no additional air needs to be added, and the oxygen requirement can be met by relying on the oxygen of the regeneration gas circulating gas. The oxygen content of the regeneration gas entering the first-stage coking zone is 1.0-3.0% by volume, the oxygen content of the regeneration gas entering the second-stage coking zone is 1.2-3.2% by volume, and the oxygen content of the regeneration gas entering the axial coking zone is 1.5-3.5% by volume.

[0016] The present invention discloses a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, and its further technical feature is that the mass ratio of the regeneration gas flow rate entering the pre-coking zone of the regenerator to the sum of the regeneration gas flow rates entering the first coking zone, the second coking zone and the axial coking zone is (1:20) to (1:5).

[0017] The present invention discloses a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, and its further technical feature is that the mass ratio of the regeneration gas flow entering the first coking zone to the regeneration gas flow entering the second coking zone and the regeneration gas flow entering the axial coking zone is (3:6:1) to (4:10:1).

[0018] The present invention provides a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, and its further technical feature is that the regeneration gas is dried by a regeneration gas drying system until the water content is no more than 20 ppm.

[0019] The present invention discloses a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, and its further technical feature is that the catalyst regeneration cycle generally has a period of 60 to 180 hours.

[0020] The present invention discloses a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, and its further technical feature is that the number of the regeneration gas inlet of the pre-coking zone, the regeneration gas inlet of the first-stage coking zone, the regeneration gas inlet of the second-stage coking zone and the regeneration gas inlet of the axial coking zone is generally 1-4.

[0021] The present invention discloses a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, and its further technical feature is that an air compressor is arranged on the supplementary air pipeline.

[0022] The present invention provides a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, and its further technical feature is that the regeneration gas cooler is preferably an air cooler or a water cooler.

[0023] The present invention provides a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, and its further technical feature is that the regeneration gas heat exchanger is preferably a plate heat exchanger or a wound tube heat exchanger.

[0024] The present invention provides a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, and its further technical feature is that the heating device is preferably an electric heater or a heating furnace.

[0025] The present invention discloses a molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, which has the following beneficial effects compared with the prior art:

[0026] 1) In the present invention, a pre-burning zone is set in the regenerator to mainly burn the carbon powder adhering to the surface and inside of the molecular sieve catalyst particles, which can effectively avoid the catalyst bed in the regenerator from overheating due to the explosion of carbon powder, and prevent catalyst caking and equipment damage.

[0027] 2) The charring zone of the present invention is divided into three sections, namely, the first charring zone, the second charring zone and the axial charring zone. After the molecular sieve catalyst is charred in the first charring zone and the second charring zone, carbon deposits still remain in the core, resulting in the problem of a black core of the molecular sieve catalyst. The use of the axial charring zone set in the regenerator of the present invention can better ensure the catalyst charring effect and ensure the distribution of the reaction products of the device.

[0028] 3) The charring area of ​​the present invention is divided into three sections, namely, the first charring area, the second charring area and the axial charring area. The regeneration gas inlets of the first charring area, the second charring area and the axial charring area are respectively supplemented with air to adjust the oxygen content of the regeneration gas to meet the requirements of the charring regeneration of the molecular sieve catalyst to be regenerated. And the temperature of the regenerator charring bed can be prevented from flying over by controlling the outlet temperature of the heating device, which not only protects the service life of the catalyst, but also prevents the regenerator from being damaged by the flying over temperature of the bed. A flexible thermocouple is provided in the regenerator to monitor the catalyst bed temperature at any time.

[0029] 4) The first regeneration gas of the present invention is heated to 420-500°C by the pre-burning zone heating device, enters the pre-burning zone from the pre-burning zone regeneration gas inlet, passes through the catalyst bed centripetally and burns off the carbon powder adhering to the surface and inside of the molecular sieve catalyst particles, and is drawn out from the pre-burning zone regeneration gas outlet at the top of the regenerator. The drawn-out high-temperature regeneration gas is combined with the second regeneration gas, which can fully utilize the heat of the high-temperature gas, reduce the energy consumption of the first-stage charring zone, the second-stage charring zone and the axial charring zone heating devices, and play a role in reducing energy and saving consumption.

[0030] 5) Two streams of regeneration gas are led out separately in the regenerator of the present invention, that is, the regeneration gas that has been charred in the pre-burning zone is extracted from the regenerator separately, the regeneration gas in the first charring zone and the regeneration gas in the second charring zone are distributed circumferentially in the regenerator space surrounded by the outer screen and the regenerator cylinder, and radially and centripetally pass through the catalyst bed and burn the carbon deposits on the catalyst. After the regeneration gas in the axial charring zone completes the charring of the residual carbon deposits in the core of the molecular sieve catalyst along the axial direction, it is collected with the regeneration gas that has been charred in the first charring zone and the second charring zone in the space surrounded by the screen in the regenerator, and is led out from the regeneration gas outlet of the charring zone. The pre-burning zone mainly utilizes the oxygen content in the circulating regeneration gas, and burns the carbon powder adhering to the surface and inside of the molecular sieve catalyst particles by adjusting the inlet temperature of the pre-burning zone heating device. In addition, the regeneration gas volume of the pre-burning zone can also be adjusted at any time. If the regeneration gas in the pre-burning zone is mixed with the regeneration gas in other charring zones, it may cause deflagration due to the excessively high oxygen content in the total mixed gas, and the pre-burning effect cannot be achieved. The regenerated gases after burning in the first burning zone, the second burning zone and the axial burning zone are combined and led out together. The main advantage is that the equipment structure is simple. In addition, the oxygen content in the three sections increases gradually, and the oxygen in the mixed gas can be fully utilized to reduce the injection of oxygen content.

[0031] 6) The regeneration gas entering the pre-burning zone, the first-stage burning zone, the second-stage burning zone and the drying zone of the present invention is the regeneration gas dried by the regenerator drying system, and has a low water content, which is beneficial to protecting the catalyst and thus prolonging its service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 The present invention is a schematic diagram of a molecular sieve catalyst regeneration and coking process for a novel moving bed light hydrocarbon conversion device.

[0033] The reference numerals shown in the figures are:

[0034] 1 molecular sieve catalyst to be regenerated, 2 regenerator buffer, 3 pre-coking zone, 4 first-stage coking zone, 5 second-stage coking zone, 6 pre-coking zone electric heater, 7 first-stage electric heater, 8 second-stage electric heater, 9 regeneration gas heat exchanger, 10 regeneration gas cooler, 11 regeneration gas drying system, 12 regeneration gas inlet pressure-stabilizing tank, 13 regeneration gas circulation compressor, 14 air, 15 catalyst feed leg, 16 inner screen, 17 outer screen, 18 regenerator space surrounded by outer screen and regenerator cylinder, 19 space surrounded by inner screen of regenerator, 20 pre-coking zone regeneration gas outlet, 21 pre-coking zone regeneration gas inlet, 22 first-stage coking zone regeneration gas inlet, 23 second-stage coking zone regeneration gas inlet, 24 regenerator, 25 thermocouple, 26 coking zone regeneration gas outlet, 27 axial coking zone regeneration gas inlet, 28 axial coking zone, 29 axial coking zone electric heater, 30 baffle. DETAILED DESCRIPTION

[0035] Combination Figure 1 The process of the present invention is described as follows:

[0036] The catalyst bed of the regenerator coking section is composed of a cylindrical inner screen 16 and an outer screen 17. The regenerator coking zone is located below the regenerator buffer zone 2 and is connected by a catalyst feed leg 15. The heating device is an electric heater.

[0037] The regenerated molecular sieve catalyst 1 after the reaction of the light hydrocarbon conversion unit enters the regenerator buffer zone 2, and enters the regenerator 24 through the catalyst feed leg 15 for charring. The regeneration charring is divided into four sections, namely the pre-charring zone 3, the first charring zone 4, the second charring zone 5 and the axial charring zone 28. The regenerated molecular sieve catalyst passes through the pre-charring zone 3, the first charring zone 4, the second charring zone 5 and the axial charring zone 28 in sequence by gravity, and contacts with the oxygen-containing regeneration gas to burn the carbon deposits on the catalyst, completing the charring regeneration process of the regenerated molecular sieve catalyst, and the regenerated catalyst is recycled.

[0038] Inside the regenerator, from top to bottom, there are the pre-burning zone, the first-stage burning zone, the second-stage burning zone and the axial burning zone. A horizontal baffle is provided between the pre-burning zone and the first-stage burning zone to block the regeneration gas in the pre-burning zone from flowing into the regeneration gas in other burning zones.

[0039] After the regeneration gas in the axial burning zone 28 burns the residual carbon deposits in the core of the molecular sieve catalyst along the axial direction, it is collected with the regeneration gas that has been burned in the first burning zone 4 and the second burning zone 5 in the space 19 surrounded by the screen in the regenerator, and is drawn out from the burning zone regeneration gas outlet 26 on the regenerator 24, and then cooled by heat exchange in the regeneration gas heat exchanger 9 tube pass, and then cooled to 45-50°C by the regeneration gas cooler 10, and enters the regeneration gas drying system 11, and is dried to a water content of no more than 20ppm (volume). The regenerated gas enters the regeneration gas inlet pressure-stabilizing tank 12, and the pressure-stabilized regeneration gas is compressed by the regeneration gas circulation compressor 13, and enters the regeneration gas heat exchanger 9 shell side heat exchange and temperature rises, and is first divided into two paths as the circulating regeneration gas. The first path of regeneration gas is heated to the required temperature by the pre-burning zone electric heater 6, enters the pre-burning zone 3 through the pre-burning zone regeneration gas inlet 21, passes through the catalyst bed centripetally and burns the carbon powder adhering to the surface and inside of the molecular sieve catalyst particles, and is drawn out from the pre-burning zone regeneration gas outlet 20 at the upper part of the regenerator 24. A baffle 30 is arranged in the regenerator 24 to block the regeneration gas of the pre-burning zone and the regeneration gas of other burning zones from interflowing. The high-temperature regeneration gas after being led out is combined with the second regeneration gas and divided into three paths, one of which is heated to the required temperature by a first-stage electric heater 7 after passing through the supplementary air 14, and enters the first-stage burning zone 4 through the first-stage burning zone regeneration gas inlet 22; the other is heated to the required temperature by a second-stage electric heater 8 after passing through the supplementary air 14, and enters the second-stage burning zone 5 through the second-stage burning zone regeneration gas inlet 23; the last is heated to the required temperature by the axial burning zone electric heater 29 after passing through the supplementary air 14, and enters the axial burning zone 28 through the axial burning zone regeneration gas inlet 27.

[0040] The regeneration gas in the first charring zone 4 and the regeneration gas in the second charring zone 5 are circumferentially distributed in the regenerator space 18 surrounded by the outer screen and the cylinder of the regenerator 24, and radially and centripetally pass through the catalyst bed and burn the carbon deposits on the catalyst. After the regeneration gas in the axial charring zone 28 completes the charring of the residual carbon deposits in the core of the molecular sieve catalyst along the axial direction, it is collected with the regeneration gas that has completed the charring in the first charring zone 4 and the second charring zone 5 in the space 19 surrounded by the screen in the regenerator, and is led out from the charring zone regeneration gas outlet 26 on the regenerator 24. The charring temperature of the entire bed in the regenerator 24 can be detected and observed by a thermocouple 25. Thermocouple 25 is a flexible thermocouple that can run through the entire regenerator.

[0041] The regeneration gas temperature entering the pre-scorching zone of the regenerator is 420-500°C, the regeneration gas temperature entering the first-stage scorching zone is 400-480°C, the regeneration gas temperature entering the second-stage scorching zone is 410-490°C, and the regeneration gas temperature entering the axial scorching zone is 420-500°C.

[0042] The water content of the regeneration gas entering the regenerator is not more than 20 ppm.

[0043] The catalyst regeneration cycle generally has a period of 60 to 180 hours.

[0044] The regeneration gas cooler is preferably an air cooler and a water cooler.

[0045] The above description is only a typical embodiment of the present invention, and does not impose any form of limitation on the present invention. Any changes or modifications made by any technician familiar with the profession, without departing from the scope of the technical solution of the present invention, using the above content should be regarded as equivalent examples of equivalent changes. Any equivalent changes made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are within the scope of the technical solution of the present invention.

Claims

1. A molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device, characterized in that The following steps are involved: 1) The regenerated molecular sieve catalyst after the reaction in the moving bed light hydrocarbon conversion unit enters the pre-burning zone of the regenerator through the catalyst feed leg for pre-burning, and then enters the burning zone of the regenerator by gravity for catalyst burning regeneration, wherein the burning zone is divided into three sections, namely, the first burning zone, the second burning zone and the axial burning zone. The regenerated molecular sieve catalyst entering the burning zone of the regenerator contacts with the oxygen-containing regeneration gas in the first burning zone, the second burning zone and the axial burning zone in turn by gravity to burn the carbon deposits on the catalyst, thus completing the burning regeneration process of the regenerated molecular sieve catalyst. The regenerated catalyst comes out from the bottom of the regenerator and is recycled; 2) Inside the regenerator, from top to bottom, there are the pre-burning zone, the first-stage burning zone, the second-stage burning zone and the axial burning zone. A horizontal baffle is arranged between the pre-burning zone and the first-stage burning zone to block the regeneration gas in the pre-burning zone from being mixed with the regeneration gas in other burning zones. The regeneration gas in the first-stage burning zone and the regeneration gas in the second-stage burning zone are circumferentially distributed in the regenerator space surrounded by the outer screen and the regenerator cylinder, and radially and centripetally pass through the catalyst bed and burn the carbon deposits on the catalyst. After the regeneration gas in the axial burning zone burns the residual carbon deposits in the core of the molecular sieve catalyst axially, it is collected with the regeneration gas that has been burned in the first-stage burning zone and the second-stage burning zone in the space surrounded by the screen in the regenerator, and is drawn out from the regeneration gas outlet of the burning zone, and then successively passes through the regeneration gas heat exchanger tube for heat exchange and cooling, the regeneration gas cooler for cooling, the regeneration gas drying system for drying, the regeneration gas inlet pressure regulating tank for pressure stabilization, the regeneration gas circulation compressor for pressure boosting and the regeneration gas After the shell side of the heat exchanger is heated up by heat exchange, it is first divided into two paths as circulating regeneration gas. The first circulating regeneration gas is heated to 420-500℃ by the pre-burning zone heating device, enters the pre-burning zone from the regeneration gas inlet of the pre-burning zone, passes through the catalyst bed centripetally and burns the carbon powder adhering to the surface and inside of the molecular sieve catalyst particles, and is led out from the regeneration gas outlet of the pre-burning zone at the top of the regenerator. The high-temperature regeneration gas after being led out is combined with the second circulating regeneration gas and then divided into three paths. One of them is supplemented with air and heated to 400-480℃ by a first-stage heating device, and enters the first-stage burning zone through the regeneration gas inlet of the first-stage burning zone; the other path is supplemented with air, heated to 410-490℃ by a second-stage heating device, and enters the second-stage burning zone through the regeneration gas inlet of the second-stage burning zone; the last path is supplemented with air and heated to 420-500℃ by the axial burning zone heating device, and enters the axial burning zone from the regeneration gas inlet of the axial burning zone.

2. The molecular sieve catalyst regeneration and coking process of a moving bed light hydrocarbon conversion device according to claim 1 is characterized in that: The light hydrocarbon conversion unit is a light hydrocarbon aromatization unit or a light hydrocarbon to propane unit.

3. The molecular sieve catalyst regeneration and coking process of a moving bed light hydrocarbon conversion device according to claim 1 is characterized in that: The operating pressure of the regenerator is 0.35-1.40 MPa, the catalyst bed temperature of the regenerator is 450-600° C., the catalyst residence time in the regenerator is 6-20 hours, and the regeneration charring includes but is not limited to four stages.

4. The molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device according to claim 1 is characterized in that: When the regeneration gas enters the pre-coking zone of the regenerator, no additional air is required, and the oxygen requirement can be met by relying on the oxygen of the circulating regeneration gas. The oxygen content of the regeneration gas entering the first-stage coking zone is 1.0-3.0% by volume, the oxygen content of the regeneration gas entering the second-stage coking zone is 1.2-3.2% by volume, and the oxygen content of the regeneration gas entering the axial coking zone is 1.5-3.5% by volume.

5. The molecular sieve catalyst regeneration and coking process of a moving bed light hydrocarbon conversion device according to claim 1 is characterized in that: The mass ratio of the regeneration gas flow rate entering the pre-scorching zone of the regenerator to the sum of the regeneration gas flow rates of the first-stage scorching zone, the second-stage scorching zone and the axial scorching zone is (1:20) to (1:5).

6. The molecular sieve catalyst regeneration and coking process of a moving bed light hydrocarbon conversion device according to claim 1 is characterized in that: The mass ratio of the regeneration gas flow rate entering the first stage charring zone to the regeneration gas flow rate entering the second stage charring zone and the regeneration gas flow rate entering the axial charring zone is (3:6:1) to (4:10:1).

7. The molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device according to claim 1, characterized in that: The regeneration gas is dried by a regeneration gas drying system until the water content is no more than 20 ppm.

8. The molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device according to claim 1, characterized in that: The catalyst regeneration cycle has a period of 60 to 180 hours.

9. The molecular sieve catalyst regeneration and coking process for a moving bed light hydrocarbon conversion device according to claim 1, characterized in that: The number of the regeneration gas inlet of the pre-coking zone, the regeneration gas inlet of the first-stage coking zone, the regeneration gas inlet of the second-stage coking zone and the regeneration gas inlet of the axial coking zone are all 1-4.

10. The molecular sieve catalyst regeneration and coking process of a moving bed light hydrocarbon conversion device according to claim 1, characterized in that: The regeneration gas cooler is an air cooler or a water cooler.

11. The molecular sieve catalyst regeneration and coking process of a moving bed light hydrocarbon conversion device according to claim 1, characterized in that: The regeneration gas cooler is an air cooler or a water cooler.

12. The molecular sieve catalyst regeneration and coking process of a moving bed light hydrocarbon conversion device according to claim 1, characterized in that: The regeneration gas heat exchanger is a plate heat exchanger or a wound tube heat exchanger.

13. The molecular sieve catalyst regeneration and coking process of a moving bed light hydrocarbon conversion device according to claim 1, characterized in that: The heating device is an electric heater or a heating furnace.

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