JPH0249359B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for treating hydrocarbon oils with hydrogen in the presence of a catalyst. More specifically, the present invention relates to an improvement in an apparatus for hydrocracking heavy hydrocarbon oils by catalytic reaction treatment under high pressure and high temperature.

Although the hydroprocessing of heavy oils is economically preferable, there are many difficult problems. One of these problems is the formation of coke on the catalyst material,
This was accompanied by clogging of the catalyst layer. A second problem has been the difficulty of maintaining a stable and satisfactory reaction temperature when the reaction that occurs is highly exothermic.

The purpose of the present invention is to eliminate pressure loss and blockage of the catalyst layer due to the formation of coke on the catalyst material, and to reduce the capacity of the device by improving the contact efficiency between the fluid and the catalyst layer. The object of the present invention is to provide a simple hydrocracking reactor with a simple structure.

U.S. Pat. No. 2,987,465 discloses that the solid is in an expanded state and has at least
It describes contacting gases, liquids, and solids in such a way that they occupy 10% more volume and are in irregular motion within a gas-liquid system. A population of solid particles in such irregular motion in a liquid or gas-liquid can be called "boiling." Ebullated beds can completely eliminate the difficulties traditionally experienced in conventional fixed bed reactors due to large pressure drops and blockages caused by carbon formation, and even more so due to the abnormal pressure drop in fixed bed reactors. It has become possible to use very highly active catalyst particles of relatively small particle size that would otherwise have been inapplicable.

However, in conventional ebullated bed reactors, raw materials (heavy hydrocarbon oil and hydrogen gas) are supplied from below the reactor and are fluidized. This device requires a distribution device, such as a dispersion plate, to increase the accumulation of catalyst in the feed nozzle and the dispersion of liquids and gases in order to feed the raw material from below.

However, this method has various drawbacks as described below.

The first is the irregularity of the dispersion effect due to the distribution device. That is, it is necessary to arrange a distribution device at the bottom of the reactor in order to increase the efficiency of gas-liquid-solid phase contact of the liquid and gas supplied from the raw material supply nozzle. In general, it is difficult to select a distribution device, and the distribution effect changes due to clogging with wear particles caused by irregular movement of the catalyst. It is difficult to do. Further, clogging of the distribution device due to the catalyst wear debris causes an increase in pressure loss, which may even lead to a shutdown of the entire device.

In addition, structurally, the lower part of the reactor has a complicated structure due to the installation of a distribution device, the increase in the number of nozzles, etc., and it has the disadvantage that it is difficult to completely extract the catalyst, clean it, etc.

The present invention has been made to overcome the drawbacks of these conventional methods, and has no economic pressure loss.
Furthermore, the present invention provides a hydrocracking reactor that is easy to control temperature, allows the use of a catalyst with a finer particle size, and is effective for heavy oil.

That is, in the present invention, in the upper part of the high temperature and high pressure reactor,
a liquid oil supply outer pipe whose one end is open to the outside, passes through the center of the reactor and reaches the bottom, and whose other end is a constricted nozzle opening; A raw material supply configured as a double pipe consisting of a hydrogen supply inner pipe inserted into the outer pipe with one end open to the outside and a hydrogen supply inner pipe having a large number of small openings at the other end protruding from the nozzle opening. This is a hydrocracking reaction apparatus for hydrocarbon oil, characterized by comprising a pipe and a gas-liquid mixture extraction pipe connecting the reactor and a gas-liquid separator following the reactor.

In the apparatus of the present invention, when hydrogen is brought into contact with liquid oil through a catalyst under high temperature and high pressure to hydrocrack it, the high temperature and high pressure reactor is filled with a catalyst having an average particle size of 0.2 to 8 mm. The hydrocarbon oil is continuously supplied from the upper part of the outside through the liquid oil supply outer pipe and is caused to pass through the catalyst layer toward the lower part while exchanging heat with the catalyst in a non-contact state, and
Similarly, 1.5 to 3 times the amount of hydrogen is fed into the hydrocarbon oil from the upper part of the outside through the hydrogen supply inner pipe toward the lower part while exchanging heat with the hydrocarbon oil in a non-contact state. , the granular catalyst, the hydrocarbon oil and Stir and mix hydrogen at 340-480℃,
a predetermined substantially isothermal temperature within 50-300 Kg/cm ² G;
It is operated in such a way that liquid phase hydrogenation is carried out while boiling under conditions of equal pressure, unreacted liquid oil and hydrogen are separated in the gas-liquid separator, and each is recycled as a raw material.

The present invention will be explained below based on the embodiments shown in FIGS. 1 and 2. In the figure, 1 is the liquid oil supply (outer pipe), which is in the form of a double pipe with the hydrogen supply pipe 2, and is the reactor 4.
It is inserted all the way to the bottom. Hereinafter, this will be collectively referred to as the raw material supply pipe.

The liquid oil and hydrogen are mixed and dispersed at the outlet of the raw material supply pipe, and are supplied to the fluidized catalyst bed 3. The liquid oil and hydrogen are preheated to predetermined temperatures by indirectly exchanging heat with the catalyst layer 3 while flowing down through the raw material supply pipes 1 and 2, respectively. In the figure, 4 indicates the reactor of the present invention, and the liquid oil that has reacted with the catalyst and hydrogen in the reactor 4 flows out from the extraction pipe 5 as a flow of oil with a smaller molecular weight and hydrogen.

The catalyst is supplied through a catalyst supply pipe 6, and extracted through a catalyst withdrawal pipe 7. In this case, since the reactor 4 does not have a distribution device for removing the catalyst, the entire amount can be easily removed without any difficulty.

Details of the raw material supply pipes 1 and 2 are shown in FIG. Liquid oil is supplied from the supply pipe 1 and flows out from the nozzle 8 toward the bottom of the reactor 4, but this nozzle 8 is constricted at the outflow section, so that it always flows out into the reactor 4 at a certain flow rate. Ru. Therefore, the nozzle 8 will not be clogged with catalyst particles. According to experiments conducted by the present inventors, hydrogen supply amount/liquid supply amount (=G/L) is 2.
In cases 3 to 3, it has been proven that setting the effective cross-sectional area of the nozzle 8 to 1 to 2 times the cross-sectional area of the hydrogen supply pipe 2 provides the most effective dispersion effect.

The hydrogen supply pipe 2 has a large number of hydrogen spout ports 9 at the bottom and the circumference at the outflow portion, and the hydrogen supply pipe 2 has a large number of hydrogen jet ports 9 at the bottom and the circumference, and the hydrogen supply pipe 2 has a large number of hydrogen spout ports 9 at the bottom and the circumference, and the hydrogen supply pipe 2 has a large number of hydrogen spouts 9 at the bottom and the circumference, and the inside of the catalyst layer 3 is mixed with and dispersed with the liquid oil that flows out as a jet and is fluidized.
is supplied to

According to this experiment, when maintaining G/L=2 to 3,
Considerable turbulence and mixing between the top and bottom of reactor 4 is obtained, reducing the minimum fluidization velocity V _nf to the superficial velocity of hydrogen.
It has been found that since it can be made equal to or higher than V _g , in many cases a means for temperature control in the hydrogenation reactor is essentially unnecessary.

(Double pipes 1 and 2 equipped with nozzle openings 8 and small openings 9 in place of heat exchange with hydrocarbon oil and hydrogen and dispersion plates)
It is thought that the temperature is stabilized by equalizing the fluidization speed by using . ) Also, the temperature gradient within the reactor 4 that normally occurs is averaged out and virtually eliminated by the mixing from top to bottom.

Therefore, if the reactor 4 of the present invention is used with finer substances than usual, there will be no difficulty in maintaining the internal circulation flow (turbulent mixing between the top and bottom of the reactor), or there will be no heat generation due to the reaction. It does not require the cost of cooling methods using low-temperature hydrogen, which are widely used for control.

Furthermore, since this type of reactor does not have a distribution device, it does not cause an increase in pressure loss due to clogging, so the pressure loss is low and there is no increase in pressure loss over time.

Figures 3, 4, and 5 show the results of hydrocracking of heavy hydrocarbon oil in Examples. In this example, a 300 mmφ x
Ni− with an average particle size of 1.6 mm was placed in a 3000 mm long reaction tube.
Mo-based alumina catalyst (NiO: 3.4wt%, MoO ₃ :
19.8wt%, _Al2O3 : balance ₎ or Co-Mo alumina catalyst (CoO: 3.3wt%, _MoO3 : 14wt%,
Al ₂ O ₃ (remaining part) is charged and hydrogen supply amount is 2 m ³ /h.
(Circulating hydrogen amount 40m ³ /h ±25%), Shell oil supply amount 1m ³ /h (Circulating shell oil amount 20m ³ /h ±25%)
Hydrogen and shell oil are supplied and circulated through the hydrogen supply pipe and liquid oil supply pipe respectively, and the average temperature is 380℃.
(340°C during the initial period of high catalytic activity, 420°C during the latter period of decreased catalytic activity) and an average pressure of 150 Kg/cm ² G. FIG. 3 shows the relationship between pressure loss and liquid superficial velocity in the case of Example A and Comparative Example B in which raw materials (liquid oil and hydrogen) were supplied from the lower part of the reactor through the distribution device into the ebullated bed. In both cases, when the amount of hydrogen is constant, as shown in the figure, in this example A, the amount of hydrogen is approximately 1/1
In Conventional Example B, the pressure loss tends to increase as the superficial liquid velocity increases, but this tendency is not observed in this example. This is an increase in pressure loss inherent to the distribution device, and it is clear that the above phenomenon does not occur at all in the case where the distribution device is not provided, as in this embodiment.

Figure 4 shows the change in pressure loss within the reactor over time. In the ebullated bed reactor of Conventional Example B, an increase in pressure loss was observed over time, but in this Example A, this tendency was not observed. I couldn't help it.

The results of the overhaul inspection revealed that in conventional models equipped with a distribution device (dispersion plate), the dispersion plate was partially clogged with catalyst powder (wear debris from mixing), which resulted in an increase in pressure loss. I can understand that there is.

Figure 5 shows the hydrocracking rate and G/L of CHSU (=supplied liquid oil amount/
Catalyst layer volume) shown under constant conditions. As shown in the figure,
When G/L is 1.5 or less, Example A exhibits a lower decomposition rate than Conventional Example B, but this is because a sufficient flow phenomenon cannot be obtained due to the small amount of hydrogen, and also because the present invention This is because the hydrogen gas supply pipe 2 is located at the center of the reactor, resulting in partial flow. However, G/L which exhibits sufficient flow =
It can be seen that the hydrogenolysis rate hardly changes between 1.5 and 3.

Next, a different embodiment of the hydrogen gas supply pipe 2 is shown in FIG.

Example a has numerous small-diameter jet ports 9-1 in order to enhance the hydrogen gas decomposition effect. The smaller the bubbles, the larger the specific surface area relative to the amount of gas, which increases the reaction efficiency and, according to the inventors' experiments, provides sufficient flow. It has been proven that when G/L=2 to 3, the dispersion effect is almost unchanged compared to the conventional method having a distribution device.

In example b, the hydrogen gas outlet 9-2 has a spiral shape as shown in its cross-sectional view b,
It applies rotational force to the catalyst layer by ejecting hydrogen gas, and is effective when G/L is low. The experimental results showed that when G/L=1, the hydrogenolysis rate was higher than in Example a. Also, G/L = 2, which provides sufficient flow.
-3 exhibited a circulation pattern in which the outside of the catalyst layer was an upward flow and the central part was a downward flow, and temperature control of the reactor was almost unnecessary.

Next, the overall flow will be described using FIG.
The supplied liquid oil and hydrogen gas were injected into a reactor 4 filled with a fluidized catalyst 3 through a double pipe composed of a liquid oil supply pipe 1 and a hydrogen gas supply pipe 2, respectively, and 50Kg/cm ² G in the reactor. Hydrogenolysis is carried out at ~300 Kg/cm ² G and 340 ~ 480°C, and then the gas-liquid mixture 5 is sent to the gas-liquid separator 10 to produce a gas product 12, a liquid product 13, and hydrogen circulation. The hydrogen circulating flow 14 and the external liquid circulating flow 15 are separated into a hydrogen supply pipe 2 and a liquid oil supply pipe 1, respectively. Further, the catalyst partially entrained in the gas-liquid mixture 5 is discharged from the solid content storage tank 11.

Although the above example describes a catalyst with an average particle size of 1.6 mm, the same effect as in the example can be obtained when the average particle size of the catalyst is small (approximately 0.3 mm) or large (5 mm). It was confirmed that

The active components of this catalyst include Co-Mo silica alumina, Ni-Mo silica alumina,
NiMo- _{P2O5 -} alumina was used.

As described above, the device of the present invention has a low pressure drop, no increase in pressure loss over time, is simple and compact in structure, and can achieve a high hydrogenolysis rate. This is a hydrocracking reactor that can easily solve the problem, and since there are no appendages at the bottom, the structure is simple, and the catalyst can be extracted very easily, making it a practically useful reactor.

Furthermore, a double pipe in which the liquid oil supply pipe 1 and the hydrogen supply pipe 2 are integrated is attached to the upper part of the reactor 4 via a flange (not shown) and suspended within the reactor 4. Therefore, if the properties or other conditions of the liquid oil change and it becomes necessary to change the jetting speed or direction of the liquid oil or hydrogen, remove the flanges and connect the raw material supply pipes 1 and 2 to the outside of the reactor 4. The nozzle 8 or the hydrogen gas spout 9 can be easily replaced by pulling it out.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an example of the device of the present invention,
FIG. 2 is an enlarged view of the raw material supply pipe portion exhibiting the double pipe structure in FIG.
The figures are a side view and a cross-sectional view showing another embodiment of the raw material supply pipe, and FIG. 7 is an explanatory diagram of an example of operation of the apparatus of the present invention.

Claims (1)

[Claims] 1. At the top of the high-temperature, high-pressure reactor, there is a liquid oil supply outer pipe whose one end is open to the outside and which passes through the center of the reactor and reaches the bottom, with the other end serving as a constricted nozzle opening; The hydrogen supply inner tube is inserted into the outer tube at a short distance from the nozzle opening of the tube, has one end open to the outside, and has a large number of small openings at the other end protruding from the nozzle opening. Hydrocracking of hydrocarbon oil, characterized by comprising a raw material supply pipe configured as a double pipe, and a gas-liquid mixture withdrawal pipe connecting the reactor and a subsequent gas-liquid separator. Reactor.