JPH057056B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for discharging particulate matter in contact with a fluid in a high-pressure vessel.

The method of the invention has a wide range of uses for the evacuation of particulate matter in contact with fluids, i.e. liquids and/or gases, from vessels in which various types of reactions, conversions, etc. operations are carried out at superatmospheric pressures. Available. The present invention is particularly useful for removing particulate materials, such as catalysts, from liquid hydrocarbon processing zones, for example. For example, the present invention particularly provides for causing hydrogenation reactions such as hydrocracking and hydrodesulfurization.
Heavy hydrocarbon oil at a high temperature of about 200 to 850℃, about 1000℃
It can be used to remove spent catalyst from a treatment zone where it is contacted with gaseous hydrogen under high pressures ranging from 5,000 psig. To bring about this type of hydrogenation reaction, hydrocarbons and hydrogen must pass upward through a bed of catalyst particles in which the catalyst particles move irregularly, creating a so-called suspended bed. I know that this is convenient.

[Purpose of the invention]

The present invention aims to provide an efficient, rapid and effective method for discharging particulate matter in a mixture with a fluid from a high pressure vessel.

It is a further object of the invention to provide a method and apparatus as described above, which allow efficient and economical separation of fluids from particulates.

Furthermore, the present invention aims to provide a method as described above, which makes it possible to remove particulate matter in a mixture of liquid hydrocarbons and hydrogen from a high-pressure hydrogenation zone.

[Structure of the invention]

Therefore, the present invention provides for placing a layer of granules in contact with a liquid in a high-pressure container having a top and a bottom,
Supporting granules in a conical shape at a location away from the bottom of the container in a high-pressure container, providing a discharge pipe to the outside of the container to discharge the granules from the bottom of the conical shape, and applying pressure to the supported granules, It consists of discharging the particulate matter to the outside of the high-pressure vessel via a discharge pipe. The present invention relates to a method for recovering a layer of particulate matter that comes into contact with a liquid in a high pressure vessel. The granules are preferably hydrogenation catalysts. In this example, liquid hydrocarbon and hydrogen feedstocks are introduced into a reactor, the feedstocks are passed upwardly into the reactor and granules to carry out the hydrogenation reaction, and the liquid and gaseous reaction effluents are transferred to the reactor. Remove from the top. Preferably, additional liquid hydrocarbon feedstock is introduced into the bottom of the granulate bed near the discharge tube, applying pressure to the supported granules and ejecting the granules from the vessel via the discharge tube. An important advantage of the process of the invention is that at least part of the particulate matter can be removed during the hydrogenation reaction. It has been found that such an operation provides optimal results.

The apparatus used in the present invention comprises a high-pressure container having a bottom and a top, a layer of granules in the container in contact with a liquid,
means for supporting a layer of particulate matter in the container in a conical shape away from the bottom of the container; a discharge pipe for draining the particulate matter from the support means to the outside of the container; and means for applying pressure to the particulate matter in order to eject the particulate matter. As mentioned above, the particulate material is preferably a hydrogenation catalyst.
Preferably, inlet means for introducing the hydrocarbon and hydrogen feedstock are provided at the bottom of the vessel, and outlet means for removing liquid and gaseous reaction effluents are provided at the top of the vessel. Preferably, the bottom of the container is provided with an inlet means and a distribution septum on the granules to enable uniform distribution of the material throughout the container. Preferably, a second inlet is provided directly below the granulate layer for introducing additional liquid hydrocarbon feedstock. Evacuation of the granulate layer through a second inlet in order to apply pressure to the supported granules to separate them so that they flow freely and to discharge the granules to the outside of the vessel via a discharge tube. A tube extending near the tube is provided.

〔Example〕

The present invention uses dynamic pressure to operate from a fixed bed in a high-pressure upflow reactor without interfering with the operation of the reactor or damaging the catalyst.
The present invention relates to a method for removing particulate catalyst.

The catalyst and reactor operate at high pressures and temperatures. The catalyst is maintained in the reactor as a fixed bed and acts in an upflow manner in the hydrogenation reaction with liquid hydrocarbons and hydrogen fed upwardly through the catalyst bed. According to the invention, the catalyst is supported in a fixed cone within the reactor and is removed from the reactor continuously or discontinuously to improve the performance of the catalyst bed. Catalyst recovery is carried out by separating the catalyst into a free flowing catalyst using high linear velocity at the bottom of a cone where the catalyst is supported. crushing the supported catalyst;
Dynamic pressure is created which moves particulates from the reactor towards a transfer line to a separator for separating the catalyst from the liquid and gaseous products. It is preferable to adjust the pressure difference between the bottom of the cone and the separator to facilitate the transport of solids in the transport line, the pressure difference ensuring a minimum linear velocity in the transport line and Preferably, the adjustment is made to maintain the catalyst in suspension.

Preferably, the liquid hydrocarbon is fed to the bottom of the cone at a high linear velocity so that dynamic pressure is created and the catalyst is separated in a free-flowing manner. Therefore, the excess liquid sucked into the reactor is discharged to the separator together with the catalyst through the transfer line without changing the conditions inside the reactor. The fixed bed is not fluidized or crushed since the flow of liquid is restricted only to the bottom of the cone supporting the catalyst. Therefore, in the case of a counterflow type fixed bed reactor, when the catalyst is withdrawn, the fixed bed moves downward to take up the space vacated by the removal of the catalyst, and the reactor continues to function.

Once the desired amount of catalyst has been removed, fresh catalyst is added from the pressurized vessel using suitable means such as a valve or by a pressure higher than that of the reactor itself.

The liquid or gaseous product is separated from the catalyst in a separator and exits the top of the separator to a high temperature and low pressure secondary
to the separator. Gas is removed from the top of the second separator, liquid is removed from the bottom,
played together. The catalyst is removed from the bottom of the separator and regenerated.

The reactor used in the present invention is a Tia
Juana) Used in the hydrogenation of hydrocarbons such as heavy oil or its residues, such as the demetalization of heavy crude oil. During operation of the reactor, a portion of the catalyst is preferably removed periodically, for example 10% of the catalyst per week.
Although the removal work takes less than one hour, it does not interfere with the operation.

Conventional hydrogenation catalysts, such as cobalt, iron, nickel, tungsten, molybdenum, etc., and their sulfides or oxides, can be used alone or with other suitable catalysts or supports. Generally, catalyst particles can be extrudates, spheres, or other irregular shapes having an average diameter of 1/32 to 1/5 inch, although other sizes and shapes are readily available. It can be adapted.

As mentioned above, the reactor is operated at high temperature and pressure. The linear velocity of the liquid used in the granule layer is 0.1 to 0.7
cm/sec. The gas (hydrogen)/liquid ratio can be easily varied between 300 and 1000 c.c./liter. The feedstock could be partially evaporated in the reactor under operating conditions. However, in any case, the liquid content of the raw material in the reactor should be maintained so that the catalyst can be recovered by liquid with a minimum pressure difference in the transport line, while the granulate layer remains in proper working order. The amount must be at least 10%. Usually lighter feedstocks are preferred.

An embodiment of the method and apparatus used in the present invention will be described with reference to the drawings. FIG. 1 is a schematic flow sheet of the entire reaction and apparatus of the present invention. As shown in FIGS. 2 to 4, the top 11 and bottom 1
A granular catalyst layer 13 is arranged in a high-pressure vessel or reactor 10 having a granular catalyst. As shown in FIG.
It is supported in a conical shape. The support means 14 is
It can be a bubble tray or the like, through which liquids and gases can pass, and arranged in a conical manner at a distance from the bottom of the lower part of the reactor. An open plate 15 in the upper part 11 of the reactor prevents expansion of the catalyst bed during operation. Additionally, a partition wall 16 is provided at the bottom 12 of the reactor to properly distribute the raw materials passing through the reactor. The reactor itself is a hydrogenation reactor, for example a conventional hydrodesulphurization reactor, with a length/diameter ratio preferably greater than or equal to 5, so that the hydrostatic pressure exerted on the bottom cone is large. I can do it. The partition wall and the open plate contain a catalyst,
Properly distributing liquids and gases helps prevent channeling from forming. This is especially important after filling the reactor with fresh catalyst to avoid catalyst shortcuts. Essentially, it is desirable that the catalyst and raw materials be properly distributed throughout the reactor. Thus, as shown, the particulate catalyst layer fills the reactor from the support means 14 up to or below the open plate 15.

An inlet 20 is provided at the bottom of the reactor for introducing the raw material via line 24 from the raw material storage means 19 . The feedstock flows upwardly through the reactor against the partition wall 16 so that it is properly distributed throughout the reactor. A discharge pipe 21 is provided extending outwardly from the support means of the container so that the particulate matter 13 can be discharged. Furthermore, means 22 are provided for applying pressure to the supported granules 13 in order to discharge the granules 13 to the outside of the reactor 10 via a discharge pipe 21 . As shown in Figure 3,
Means 22 is a second inlet for introducing the raw material into the vicinity of the discharge pipe 21 and just below the catalyst layer. Second inlet 2
Introducing additional feedstock through 2 results in a high linear velocity at the bottom of the cone. The granules are normally supported in a cone, but the high linear velocity of the feedstock from the second inlet 22 creates a dynamic pressure that dislodges the supported granules. and raw materials flow out of the reactor via the discharge pipe 21.

Thus, upon operation of the reactor, liquid and gaseous feedstocks enter the reactor 10 through the bottom inlet 20 and are gradually distributed below the catalyst-supporting cone 14 and into the reactor 10 through the partition wall 16. distributed throughout. The reaction effluent exits the top of the reactor via outlet 23. If it is desired to remove particulates from the reactor, additional liquid feed is introduced via a second inlet 22 at the bottom of the cone supporting the catalyst in an arcuate manner. In order to apply dynamic pressure to the supported catalyst arches, crushing the arches and forcing the catalyst out of the discharge pipe 21 as indicated by the arrows in FIG. The liquid is sucked up through the injection port 22 of No. 2. When the catalyst arch is broken by the dynamic pressure of additional feed through the second inlet 22, the catalyst and liquid are discharged into the discharge pipe 2.
removed from 1. This operation can be carried out even if the catalysts are stuck together, for example with vanadium or carbon, since the catalyst clumps are broken by the hydraulic pressure.

In FIG. 1, particulate matter 13 removed from reactor 10 through discharge pipe 21 is transferred to hot separator 30.
carried to. The particulates are separated from the slurry by separator 30 and discharged from the bottom of separator 30 via discharge line 31 and high pressure, high temperature rotary valve 32 for regeneration, reprocessing or storage. Liquid and gas are separated from the slurry and sent through line 33 to a second separator 34.
A second separator 34 separates the gas and connects it to a second via line 35 and valve 36 for storage or regeneration.
The gas is discharged from the top of the separator. Liquid is discharged from the bottom of the second separator 34 via line 37 and a high temperature, high pressure pump 38.
At the bottom of the second separator 34, particulate matter is deposited at the pump 3.
A filter is provided to prevent it from falling into the 8 range. The pump 38 pumps the liquid to the heater 39,
Furthermore, for regeneration, the second injection port 22 is connected to the heater 39.
It can be pumped to Liquid can also be pumped through valves 40 and 41 to discharge line 31 for storage or regeneration, or to line 4.
2 to the discharge line 31.

Microprocessor 50 controls various functions indicated by dotted lines in FIG. These functions can also be controlled manually. A solid level detector 51 and a liquid level detector 52 controlled by a microprocessor 50 are provided in the reactor 10 to ensure that the solid and liquid levels in the reactor 10 are at appropriate heights. You can also do it. Also,
The microprocessor 50 can also control a solids level detector 53 in the separator 30 and a valve 32 that removes particulates from the separator 30. Microprocessor 50 may also control valve 36 to vent gas and valve 40 to vent liquid from second separator 34.

The catalyst to be supplied is connected to line 62 and valve 63.
The high-temperature and low-temperature containers 61 are connected to
A low pressure container 60 is stored. The container 60 is
It communicates with reactor 10 via line 54 and valve 65. The container 60 is equipped with a solid state level detector to maintain the height of particulate matter within the container. Detector 66 and valves 63, 65 are controlled by microprocessor 50.

According to the invention, therefore, if it is desired to remove some or all of the catalyst from the container 10, the heated liquid can be pumped through the second inlet 22. Additional ingredients could be added as needed. Gradually increase the flow rate to break up the arch of granules at the bottom of the cone. The actual flow rate will depend on variables such as particulate size, shape, and conditions within the vessel 10. Once the solids transfer begins, the flow rate of the liquid in the second inlet 22 is maintained until the desired amount of particulate matter has been collected.

Controlling the pressure difference between the separator 30 and the particulate material includes:
Special care must be taken. Typically, the pressure differential range is about 50 to 100 psig. This pressure difference can be adjusted step by step from the start of particulate collection to during the collection process by solid state level detectors.

If solids are not removed, solid state detector 51
The flow rate in inlet 22 is gradually increased until the inlet 22 indicates removal of solids. Typically, the maximum speed is about 5 cm/sec. The flow rate can then be maintained or reduced to the minimum velocity to move the solids. To remove solids, the pressure difference between reactor 10 and separator 30 is increased to the maximum value mentioned above.
Or it can be increased to near the maximum value. If this value is exceeded, the catalyst may be damaged and carried to the second separator.

In this embodiment, the microprocessor 5
0 from container 60 to container 10 using a solid state detector.
Begin introducing catalysts into the After filling the container 10 with liquid, particulate matter can also be caused to flow by injecting liquid into the container 60 via pump 70 and line 71 (FIG. 4).

If it is necessary to prevent particulates from sticking to the discharge line 31, the microprocessor reduces the flow rate and cleans the discharge line 31 once the desired amount of catalyst has been discharged and fresh catalyst has been added. You can do it like this.

In order to illustrate the method and apparatus of the present invention, a comparative experiment (Test 1) was carried out using the reactor and flat catalyst support shown in Figure 1 and without changing the catalyst during operation. A comparison was made with the case using the method and apparatus of the invention (Test 2). Test 1
Both Test 2 and Test 2 were conducted for one month, and in Test 2, 10% of the catalyst was replaced every 5 days. In both tests, heavy crude oil feedstocks as shown in Table 1 were demetalized using hydrogen in a countercurrent manner. In test 1, the reactor temperature was gradually increased from 370°C (initial temperature) to 400°C (final temperature). Test 2 was conducted at constant temperature. In test 1 and test 2, the overall pressure was 1800 psig and the LHSV (ratio of fresh feed volumetric flow rate to reactor volume) was
It was 0.3.

The level of demetalization for test 1 was maintained at 75%;
Product quality was measured at various times. After one month of working, the quality of the product changed. The results are shown in Table 1. Table 1 shows that test 1 causes a change in quality and an increase in conversions. Considering that conversion is more beneficial than quality, the final stage with higher conversion is more profitable.

FIG. 5 shows the change in temperature over time for test 1. FIG. 6 shows the loading of vanadium and carbon, and FIG. 7 shows the appearance of vanadium in the catalyst at the top, middle and bottom of the reactor.

According to Test 1, for a constant demetallization level, the rate of metal deposition on the catalyst is constant and the metal loading on the catalyst increases linearly as a function of time. Vanadium on the catalyst decreases with reactor length. The rate at which vanadium attaches to the catalyst is faster at the top of the reactor and slower at the bottom. On the other hand, the carbon content is higher at the outlet than at the inlet. The distribution of vanadium on the granules is not uniform. According to a microprobe analysis as shown in FIG. 7, there is more vanadium on the outside than in the center of the granules.

According to the present invention (Test 2), as shown in Table 1, the degree of conversion, demetallization and desulfurization of the residue is increased. At the same time, the initial and final quality of the product decreases slightly, but the change is negligible compared to test 1. The amount of fraction formed in test 2 is approximately constant, which is also advantageous.

FIG. 8 shows the evolution of demetalization over time in test 2. Figure 9 shows the carbon and vanadium filling. The carbon and vanadium are completely different from those in Test 1; in the reverse flow method, the amount of carbon deposited is small and the distribution of vanadium along the catalyst layer is flat.

The distribution of vanadium in the granules is also different, with a higher amount of vanadium deposited in the center of the granules (see Figure 10), demonstrating the superiority of the method and apparatus according to the invention.

〔Effect of the invention〕

As mentioned above, according to the method of the invention, fluids, i.e. liquids and/or gases, are contacted from a container in which various types of reactions, conversions, etc. are carried out at pressures above atmospheric pressure. Particulate matter can be discharged and discharged. In particular, according to the present invention, particulate catalyst can be removed from the fixed bed of a counterflow reactor operated at high temperatures without interfering with the operation of the reactor and without damaging the catalyst.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing the entirety of the method according to the invention and the apparatus used; FIG. 2 is a detailed sectional view showing the top of the reactor in FIG. 1; and FIG. 3 is a detailed sectional view showing the bottom of the reactor in FIG. Figure 4 is a detailed cross-sectional view of the upper part of the reactor in Figure 1 showing the introduction of particulate matter into the reactor; Figure 5 is a detailed cross-sectional view of the upper part of the reactor in Figure 1 showing the introduction of particulate matter into the reactor; Figure 6 is a graph showing carbon and vanadium versus reactor length for comparative data; Figures 7a, 7b and 7c are graphs showing the distribution of vanadium in particulate catalysts by microprobe X-ray analysis for comparative data; FIG. 8 is a graph showing the change in demetallization over time according to the method of the invention; FIG. 9 is a graph showing carbon and vanadium versus reactor length according to the method of the invention; FIG. 10a and 10b The figure is a diagram showing the results of microprobe X-ray analysis of vanadium distribution in a granular catalyst when using the method of the present invention. 10... High pressure container, 13... Granular catalyst layer, 14
...supporting means, 21...discharge pipe, 22...pressurizing means.

【table】

【table】

Claims (1)

[Scope of Claims] 1. A method for extracting solid particulates maintained in contact with a liquid in a layer in a high-pressure vessel in a hydrogenation reaction, the method comprising: a high-pressure vessel having a bottom and an upper part; A high pressure vessel is provided containing a layer formed of solid particulates comprising a hydrogenation catalyst in contact with a liquid in the vessel; the solid particulates being supported in the vessel and spaced apart from the bottom of the vessel. forming a cone spaced apart from the granules; providing a discharge pipe in communication with the granules to conduct the material from the cone to the outside of the vessel; supplying a raw material consisting of liquid hydrocarbon and hydrogen at a first linear velocity to a first inlet; the raw material is passed upwardly through the vessel and the solid particles to carry out the hydrogenation reaction, while the liquid and gaseous reaction products are simultaneously withdrawn from the top of the vessel; selectively introducing additional hydrocarbon feedstock into the bed of granules at a conical section proximate the discharge pipe at a second linear velocity greater than the first linear velocity via two inlets to support the granules; generating pressure above the granules to extract the granules out of the container via the discharge pipe. 2. The method according to claim 1, further comprising the step of periodically withdrawing at least a portion of the solid particles during the progress of the reaction. 3. A method according to claim 1, characterized in that the material is passed through a partition in the lower part of the cone and dispersed through the container. 4. The method according to claim 1, further comprising the step of introducing the extracted particulate matter into a separator to separate solid particulate matter from liquid and gas. 5. The method of claim 4, further comprising the step of providing a pressure difference between the separator and the reaction vessel to facilitate withdrawal of particulate matter.