CN1127556C - Reforming catalyst regenerating process and apparatus with continuous axial and radial flow combined bed - Google Patents

Abstract

The invention belongs to the reforming and regeneration of petrochemical catalysts. The catalyst carbon deposition burning process is as follows: the deactivated catalyst enters the first zone and the regeneration gas flows downward to contact, and burns 60-80% of the carbon deposits; the first zone regenerates the flue gas Supplementary gas and quenching gas are mixed in the second zone to contact with the catalyst coming down from the first zone to burn the remaining carbon deposits. The catalyst distributor of the present invention is funnel-shaped and communicates with the feeding channel. There is a first section of conical screen and an axial flow moving bed below it, and the lower part of the runoff moving bed of the second section is separated from the chlorination oxidation zone. The channel communicates with the chloride oxidation zone. The bed temperature of the invention is evenly distributed along the radial direction, which is easy to control, the oxygen in the regeneration gas can be fully utilized, the flow rate of the regeneration gas can be reduced by nearly 40%, the inlet temperature of the regeneration gas can be reduced to 445°C, and the utilization rate of the equipment is high.

Description

Process method and equipment for continuous shaft and radial combined bed regeneration of reforming catalyst

The invention belongs to the technical field of petrochemical industry, relates to catalyst reforming and regeneration, in particular to a process for burning off carbon on the surface of reforming catalysts, and relates to a reforming catalyst continuous shaft and runoff combined bed regeneration process and equipment.

Catalytic reforming is an important process for the production of high-octane gasoline, aromatics and cheap hydrogen. Reforming processing capacity is one of the important indicators to measure the advanced petrochemical technology. In areas with relatively developed technology, reforming processing capacity accounts for about 20% of crude oil processing volume, while in relatively less developed areas, reforming capacity can only account for 20% of crude oil processing volume. about 5%. With the development of the petrochemical industry, the demand for aromatics has increased greatly. At the same time, due to the increasing quality of gasoline due to environmental protection requirements, the demand for high-octane gasoline without lead has increased rapidly. Catalytic reforming will inevitably have greater development in the future. .

Continuous catalytic reforming has the characteristics of low operating pressure, small hydrogen-to-hydrocarbon ratio and continuous catalyst regeneration. Currently, there are two continuous reforming technologies, UOP in the United States and IFP in France. In the reforming process, the continuous catalyst regeneration technology is the key to continuous catalytic reforming. UOP and IFP have carried out several updates on the regeneration technology. So far, UOP has developed three generations of technology, and IFP has developed two generations of technology. The third-generation UOP continuous catalytic reforming technology is also called Cycle Max process, the reaction pressure is 0.35MPa, the regeneration pressure is 0.25Mpa, and the coking section of the regenerator adopts a radial flow combined bed structure. The screen of the burnt section is changed from the first and second generation cylindrical to conical to improve the defects of the original cylindrical screen with uneven temperature distribution and uneven catalyst flow. In 1991, IFP launched the second-generation continuous catalytic reforming process with a reaction pressure of 0.35MPa and a regeneration pressure of 0.55MPa. The regenerator is changed from the first generation of fixed bed to runoff moving bed. At the top of the regenerator is the catalyst storage area, and there are four independent areas below: the main combustion area, the final combustion area, the oxychlorination area, and the burning area. The charred part of the regenerator adopts a runoff moving bed structure with high efficiency. European patent EP0378482 discloses the processing method and conditions of the above technology.

The coking section of UOP third-generation and IFP second-generation continuous catalytic reforming regeneration processes adopts a radial-flow moving bed structure. US patents US5,034,117, CN1201718A, and CN86108969 all disclose this method and structure. The main disadvantages of the structure are (1) The oxygen utilization rate in the regeneration gas is low, and the required regeneration gas flow rate is large, resulting in a large power consumption; (2) The inlet temperature of the regeneration gas in the first stage is relatively high, and the heat released by burning cannot be fully utilized; (3) ) The temperature distribution along the runoff of the charred section is uneven, and an over-temperature zone is prone to appear at the screen in the first section; (4) The utilization rate of the charred section is low.

The purpose of the present invention is to provide a method that conforms to the charcoal burning mechanism so that the oxygen in the regeneration gas can be fully utilized, thereby reducing the amount of regeneration gas and lowering the bed temperature. Fully utilized reforming catalyst continuous shaft, radial flow combined bed regeneration process method and equipment.

The present invention is realized through the following technical solutions:

The reforming catalyst continuous shaft and runoff combined bed regeneration process method of the present invention includes the burning of catalyst carbon deposits, catalyst chlorination and oxidation, the chlorination and oxidation zone is separated from the catalyst carbon deposit burnout area, and the catalyst carbon deposit burnout process for:

a. The deactivated catalyst particles discharged from the reforming reaction system enter the regeneration zone;

b. In the first zone of the regeneration zone, the deactivated catalyst particles are in parallel flow contact with the regeneration gas in the same direction, and burn 60-80% of the carbon deposit on the deactivated catalyst;

c. The catalyst particles that have completed most of the charring in the first zone of the regeneration zone enter the second zone of the regeneration zone;

d. The mixture of regeneration flue gas flowing out of the first zone, supplementary air and quenching gas is in contact with the catalyst particles flowing down from the first zone in the second zone of the regeneration zone to burn off the remaining carbon deposits.

The reforming catalyst continuous shaft and radial combined bed regeneration process method of the present invention also includes: the temperature at the inlet of the regeneration gas in the first zone of the process b is 445°C-465°C.

The reforming catalyst continuous shaft and radial flow combined bed regeneration equipment of the present invention comprises an upright container with a catalyst charcoal burning zone and a chlorine oxidation zone inside, a catalyst distributor 5 in the upright container, a catalyst inlet 4 on the top, and a regeneration gas inlet on the side 3. Supplementary air and quenching air inlet 2, regeneration gas outlet 1, the catalyst distributor 5 is funnel-shaped, the edge is connected to the inner wall of the upright container, and the lower end is connected to the feeding channel 6; there is a first section of axial flow moving bed below the catalyst distributor 5 8. The lower part of the axial flow moving bed 8 is composed of a conical screen 9, the upper edge of the conical screen 9 is connected to the inner wall of the upright container, and the upper end of the feeding channel 6 is connected to the lower end of the conical screen 9 and the radial flow bed 12 Connected, the radial fluidized bed 12 is surrounded by the inner screen 10 and the outer screen 11 screens, and the radial fluidized bed 12 is connected with a feeding channel 6, and the lower part of the runoff moving bed 12 is separated from the chlorination oxidation zone 13. The end of the feeding channel 6 communicates with the chlorination oxidation zone 13.

The reforming catalyst continuous shaft and radial flow combined bed regeneration equipment of the present invention also includes:

Catalyst distributor 5, conical screen cloth 9, and the feeding channel 6 at the lower end of radial fluidized bed 12 are formed by more than two garden pipes respectively.

The catalyst distributor 5, the conical screen 9, and the feeding channel 6 at the lower end of the radial flow bed 12 can be formed by a complete annular pipe.

The center of the conical screen cloth 9 upper end of the axial flow moving bed 8 can be connected with the inner pipe 7, and the inner pipe 7 is a closed garden pipe at the upper end, forming an annular space with the inner wall of the upright container.

The regeneration gas inlet is located in the upper part of the vertical container and in the middle of the feed channel 6 at the lower end of the catalyst distributor 5; the supplementary air and quenching gas inlet is located in the middle of the feed channel 6 at the lower end of the axial flow moving bed in the middle of the vertical container; the regeneration gas outlet is located in the lower part of the vertical container And the middle part of the feed channel 6 at the lower end of the radial flow moving bed.

The present invention adopts a brand-new axial and radial flow moving bed combination technology. Compared with the radial flow moving bed, the bed temperature can be evenly distributed along the radial direction, the bed temperature is easy to control, and the burning ratio can be flexibly adjusted, so that The oxygen in the regeneration gas can be fully utilized, and the flow rate of the regeneration gas can be reduced by nearly 40%; the inlet temperature of the regeneration gas in the axial flow can be reduced to 445°C, and the burning ratio of the axial and radial flow beds can be flexibly adjusted within the range of 60-80%. The total effective bed height of the axial and radial flow beds can be controlled within 2.5 meters, and the equipment utilization rate of the coking section is relatively high.

The accompanying drawings of the present invention are as follows:

Fig. 1 is a structural diagram of device embodiment 1 of the present invention;

Fig. 2 is a structural diagram of Embodiment 2 of the device of the present invention.

The present invention is proposed on the basis of research on coking dynamics and fluid mechanics mechanism of moving bed. Through the study of carbon burning kinetics, it is found that there are three types of carbon deposits with large differences in combustion performance on the reforming catalyst, which are called type I carbon, type II carbon and type III carbon respectively. Type I char burns faster and has a lower ignition temperature. Through the study of the fluid mechanics of the axial and radial flow moving bed, it is found that many hydrodynamic characteristics of the axial flow moving bed are more suitable for the coking mechanism of the reforming catalyst.

The principle of the invention is: adopting the moving bed technology, the regeneration gas can make full use of the oxygen in the regeneration gas through the entire coking section along the axis and runoff at one time; Heating the catalyst in the bed to reach the light-off temperature of type II and type III charcoal, so that the inlet temperature of the first regeneration gas can be reduced accordingly, and the heat of charcoal burning can be fully utilized; due to the use of axial and radial flow moving bed The process can control the scorching amount and maximum temperature of the first stage through the oxygen content of the first stage, so the operation is flexible and the adjustment is convenient.

The reforming catalyst regeneration method of the present invention comprises the burning off of catalyst carbon deposit, catalyst chlorination and oxidation, and the chlorination and oxidation zone is separated from the catalyst carbon deposit burning zone, and the catalyst carbon deposit burning process is as follows:

a. The deactivated catalyst particles discharged from the reforming reaction system enter the regeneration zone by weight;

b. In the first zone of the regeneration zone, the deactivated catalyst particles are in parallel and downward contact with the regeneration gas having a lower inlet temperature, and burn 60-80% of the carbon deposits on the deactivated catalyst;

c. The catalyst particles that have completed most of the charring in the first zone of the regeneration zone enter the second zone of the regeneration zone by weight;

d. The mixture of regenerated flue gas flowing out of the first zone, supplementary air and quenching gas is in contact with the catalyst particles flowing down from the first zone in the second zone of the regeneration zone, and burns off the remaining accumulation on the deactivated catalyst carbon.

Example 1 of the equipment of the present invention adopts the following design, the top of the axial and radial flow combined bed is a catalyst distributor 5, the lower part of the distributor 5 is the first section of the axial flow bed 8, and the bottom of the first section of the axial flow bed is a conical screen 9 , the lower part of the conical screen 9 is the second section of runoff bed 12, and the lower part of the second section of runoff bed is the chlorine oxidation section 13. The bottom of distributor 5, conical screen cloth 9, runoff bed 12 is all connected with feeding pipe 6, and feeding pipe 6 can be many garden pipes, and the quantity of garden pipe can be 4,6,12 or more. The feeding pipe 6 can also be a complete annular cylinder formed by two plates. The regeneration gas inlet is located in the upper part of the vertical container and in the middle of the feed channel 6 at the lower end of the catalyst distributor 5, the supplementary air and quenching gas inlet is located in the middle of the vertical container and in the middle of the feed channel 6 at the lower end of the first section of the axial flow moving bed, and the regeneration gas outlet It is located at the lower part of the upright container and the middle part of the feeding channel 6 at the lower end of the second section radial flow moving bed. The lower part of the second section radial flow moving bed 12 is separated from the chlorination and oxidation zone 13, and only the end of the feeding channel 6 at the lower end communicates with the chlorination and oxidation zone 13.

The device of the present invention includes the following steps when working: (1) The catalyst inlet 4 enters the distributor 5 for redistribution. (2) The catalyst entering the catalyst distributor 5 uniformly flows into the first stage axial flow bed 8 along the feed pipe 6 . (3) The regeneration gas coming in from the first-stage regeneration gas inlet 3 and the catalyst entering the first-stage axial-flow bed 8 flow downward in the same direction as a moving bed, and the catalyst enters the second-stage radial-flow bed 12 from the feeding pipe 6 . (4) After the air from the first section regeneration gas inlet 2 is mixed with the quenched air, the outer screen 11 of the second section runoff bed 12 is passed through the inner screen 10 along the substantially transverse runoff of the downward movement direction of the catalyzer from the outer screen 11 of the second section runoff bed 12. After the feeding pipe 6, it enters the chlorine oxidation section 11. (5) The above-mentioned gas is discharged through the regeneration gas outlet 1 passing through the bottom of the runoff bed 12 .

Example 2 of the equipment of the present invention adopts the design substantially the same as that of Embodiment 1, and the difference is that an inner pipe 7 is connected at the center of the upper end of the conical screen cloth 9 of the axial flow moving bed 8, and the inner pipe 7 is a closed garden pipe at the upper end. It forms an annular space with the inner wall of the upright container, and the feeding channel 6 at the lower end of the distributor 5 stretches into the annular space.

Claims (7)

1. A reforming catalyst continuous shaft, radial flow combined bed regeneration process method, including the burning of catalyst carbon deposits, catalyst chlorination and oxidation, is characterized in that: the catalyst carbon deposit burning area of the chlorination and oxidation zone is separated, and the catalyst The carbon deposit burning process is: a. The deactivated catalyst particles discharged from the reforming reaction system enter the regeneration zone; b. In the first zone of the regeneration zone, the deactivated catalyst particles are in parallel flow contact with the regeneration gas in the same direction, and burn 60-80% of the carbon deposit on the deactivated catalyst; c. The catalyst particles that have completed most of the charring in the first zone of the regeneration zone enter the second zone of the regeneration zone; d. The mixture of regeneration flue gas flowing out of the first zone, supplementary air and quenching gas is in contact with the catalyst particles flowing down from the first zone in the second zone of the regeneration zone to burn off the remaining carbon deposits. 2. The reforming catalyst continuous shaft and radial flow combined bed regeneration process according to claim 1, characterized in that: the inlet temperature of the regeneration gas in the first zone of process b is 445°C-465°C. 3. A reforming catalyst continuous shaft, radial flow combined bed regeneration equipment, including an upright container with a catalyst charcoal burning area and a chlorine oxidation area, a catalyst distributor 5 in the upright container, a catalyst inlet 4 on the top, and regeneration on the side Gas inlet 3, supplementary air and quenching air inlet 2, regeneration gas outlet 1, characterized in that: the catalyst distributor 5 is funnel-shaped, the edge is connected to the inner wall of the upright container, and the lower end is connected to the feeding channel 6, and there is a second catalyst distributor 5 below A section of axial flow moving bed 8, the lower part of the axial flow moving bed 8 is composed of a conical screen 9, the upper edge of the conical screen 9 is connected to the inner wall of the upright container, and the upper end of the feeding channel 6 is connected to the lower end of the conical screen 9 Connected with the radial flow bed 12, the radial flow bed 12 is surrounded by an inner screen 10 and an outer screen 11, and the radial flow bed 12 is connected with a feeding channel 6, and the lower part of the radial flow bed 12 is connected with the chlorination The oxidation zone 13 is separated, and the end of its feeding channel 6 communicates with the chlorination oxidation zone 13. 4. The reforming catalyst continuous shaft and radial flow combined bed regeneration equipment according to claim 3 is characterized in that: the catalyst distributor 5 and the conical screen 9, the feeding channel 6 at the lower end of the radial fluidized bed 12 are respectively composed of two The garden tube above the root constitutes. 5. According to claim 3, 4 described reforming catalyst continuous axis, radial flow combined bed regeneration equipment, it is characterized in that: catalyst distributor 5 and conical screen cloth 9, the feeding channel 6 at the lower end of radial flow bed 12 can be by A complete annular tube constitutes. 6. The reforming catalyst continuous shaft and radial flow combined bed regeneration equipment according to claim 3, characterized in that: the center of the upper end of the conical screen 9 at the lower part of the axial flow moving bed 8 can be connected to the inner pipe 7, and the inner pipe 7 is the upper end The closed garden pipe forms an annular space with the inner wall of the upright container. 7. The reforming catalyst continuous shaft and radial flow combined bed regeneration equipment according to claim 3 is characterized in that: the regeneration gas inlet is located at the upper part of the upright container and in the middle part of the feed channel 6 at the lower end of the catalyst distributor 5; The cold air inlet is located in the middle of the vertical container and the middle part of the feed channel 6 at the lower end of the first section of the axial flow moving bed; the regeneration gas outlet is located in the lower part of the vertical container and the middle of the feed channel 6 at the lower end of the second section of the radial flow moving bed.

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