JPS59179144A - Reaction apparatus - Google Patents

Abstract

PURPOSE:To control reaction temp. uniformly and to recover the heat of reaction by providing a solid/gas separation zone to the upper part of heat transmission pipes provided to the periphery of a reaction pipe, and a large cyclone contg. a small cyclone in the inside to the upper part of the solid/gas separation zone. CONSTITUTION:Catalyst is packed in the bottom of a reactor 20, and preheated feed gas(H2/CO) is blown through a nozzle 3 into the reactor 20 and is made to flow upward in the reaction pipe 4. The packed catalyst is sucked in this stage into the reactor 4 and is moved in the mixing condition of the solid with the gas from the bottom of the reactor upward, causing thereby F-T reaction to form hydrocarbons. The solid/gas fluid mixture which has passed through the reaction pipe 4 is transferred to a solid/gas separation zone 6 having a wide inside shell dia. at the middle section of the reactor 20 causing sudden decrease of the flow rate of the gas. Accordingly a denser fluidized layer is formed and the gas alone is transferred to the top of the reactor 20 and the solid is separated from the gas.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a reactor for a substance that causes an exothermic reaction, and in particular, by efficiently removing reaction heat from the system, the temperature of the reactant can be controlled at a constant level, and high quality products can be produced. The present invention relates to a fluidized bed reactor capable of improving the quality of the product by increasing the separation efficiency of the product gas and solid particles and preventing entrainment of solid particles into the product.

Examples of exothermic reactions that synthesize hydrocarbons using hydrogen and carbon oxide as raw materials include the F-T synthesis reaction (Fischer
Examples include Tropsch synthesis reaction (hereinafter abbreviated as FT synthesis reaction), hydrogenation reaction, and the like.

Now, an explanation will be given using the FT synthesis reaction as an example.

, the basic reaction of FT synthesis is as follows.

(500'K) Co + 2H2→("H2-)+H20...=・5
9.5 K cal (1)2CO+H2-+ (-
CH2-)+CO,・-=・48.9 K cal (
2) Co-4-H2O-+ H2+Co2----
9.5Kcal (3) Normally, the main reaction is the formula (1), but the formula (2) occurs with Fe-based catalysts, etc., and the content is (
It consists of the sum of equation 1) and equation (3) (shift reaction). (1)
If the equation is repeated, the olefinic hydrocarbon Cn E(2n
However, in reality, paraffins and aromatic hydrocarbons are also produced, and alcohols and other oxygen-containing compounds are also produced as by-products.

Thermodynamically, all hydrocarbon production reactions from synthesis gas are exothermic. For this reason, the free energy change is large at high temperatures, and equilibrium is disadvantageous for the production system (see Figure 1), but at reaction temperatures below 550°C, the horizontal constant for most reactions is greater than 1. be. Furthermore, since the F −'[' synthesis reaction involves a decrease in the number of moles, it is advantageous for the production system to perform it under pressure.

There are two types of reactors currently used for fuel oil production by FT synthesis reaction, as shown in FIGS. 2 and 3.

The reactor shown in Figure 2 is called an Algi reactor and is a heat exchanger type, with a catalyst bed length of about 13 m and a shell diameter of about 6.
m, and about 6 = 2,000 2-inch heat exchanger tubes are packed inside. A precipitated iron catalyst in the form of pellets is filled in this chamber 6, and the temperature of the hot water on the nonyl side is controlled by adjusting the steam pressure. The raw material synthesis gas heated by a heat exchanger (not shown) is supplied from the gas inlet nozzle 1 at the top of the reactor, and when passing through the catalyst layer inside the heat transfer tube 6, it passes through the F-T.
A synthetic reaction is performed to produce hydrocarbons. The generated gas is extracted to the outside of the device from the gas outlet nozzle 8. The high-boiling hydrocarbons (wax) produced at this time flow down inside the heat transfer tube 6 and are extracted from the wax outlet nozzle 9 at the bottom of the reactor, but these hard waxes (having carbon numbers of 60 or more) Due to the poor fluidity, some of it accumulates on the surface of the catalyst, deteriorating the catalyst activity, and if the amount of accumulation increases further, it may cause clogging of the reaction tube (51+). Therefore, we wash it intermittently every few days with produced oil (suitably diesel oil fraction) with an appropriate boiling point range.
Removes residual wax.

The reaction heat generated in the FT synthesis reaction is transferred to the boiler water in the nozzle 6 flowing outside the heat transfer tube B, and the steam generated by the evaporation of this water is extracted from the steam outlet nozzle 2.

In addition, in FIG. 2, 4 is a steam heater, 5 is a steam collector 2, and 7 is a cylinder.

The fixed bed reactor shown in Figure 2 above has a limit to scale-up due to the size of the practical device, so multiple reactors are used in parallel. However, in the case of multiple reactors, productivity is low and handling is complicated (as in Pj+J) (wax production Dodai), so it is not efficient and has not been adopted in recent new plants.

- The circulating flow M reactor shown in Figure 6 is called a synthol reactor, and has a dilute transport layer (entrain 8d bed) in which the catalyst powder is entrained in the air flow and reacted.
) method. The catalyst is an iron-based fine powder of 400 mesh or less. The raw material gas is mixed with recycled gas,
tm and 160° C. from the raw material/charging gas supply nozzle 11 through the riser 5 into the reactor. Catalyst hopper 7
The catalyst at 655℃ stored in stand pipe 8
flows down, and the slide valve 9 controls the flow it'5tfQJ.
! It is divided into four sections and mixed with the raw material gas. The temperature of the mixture rises to nearly 670°C due to the heat of reaction. Here, the mixture of catalyst and reaction gas is cooled to about 550° C. in a shell-tube type two-stage heat exchange 'a2. The mixture passes through the tube side, and the cooling oil on the shell side supplied from the cooling oil inlet nozzle 6 is extracted from the cooling oil outlet nozzle 4 and supplied to an external heat exchanger (not shown), where it is converted into water vapor. generate. In addition, in FIG. 3, 6 is a cyclone, and 10 is a tail gas outlet nozzle.

Regarding the heat exchanger 2 described above, when the temperature decreases due to cooling, wax is not generated, and this wax is deposited on the catalyst surface, blocking most of the cooling pipe 12 and reducing the cooling area. Operating conditions, cooler model selection, etc. are important.

In this reactor, the catalyst particles are moved vigorously through the dilute transport layer to prevent the catalyst from coagulating, and at the same time, the catalyst particles act as heat carriers, resulting in good heat removal efficiency. Since this reactor consists of the catalyst hopper 7 and the reactor 1, the amount of catalyst held up is larger than that of a fixed bed.

Furthermore, since the area of friction between the inner wall of the cooler and the catalyst increases, there is a lot of wear and tear on the catalyst.

Table 1 shows fixed bed reactor The operating results of the moving bed reactor (Figure 6) are shown in comparison.

In the case of a fixed bed, gasoline, diesel oil, and waxes are the main products, and waxes are particularly abundant. On the other hand, in the circulating fluidized bed, there is a large amount of gasoline fraction, and very little kerosene/gas oil fraction and wax are produced.

Table I Yield of F-T method [(Source) Hoogendoorn, J.C.: P
reprint of ”IGTSympos
(1975)) The second method for producing hydrocarbons from synthesis gas is the hydrocol method, and the equipment shown in Figure 4 is known as the equipment used in this method. This method forms a dense fluidized bed of catalyst particles in the tower, and a cooling device using pressurized water is built into the furnace to adjust the reaction temperature.

In FIG. 4, raw material gas supplied from a gas inlet nozzle 1 is blown into a fluidized bed section 6, where it comes into contact with a catalyst to cause a synthesis reaction. The generated gas is extracted from the reaction tower through the gas outlet nozzle 2. On the other hand, heat transfer tubes 5 are disposed within the fluidized bed section 6 to transfer heat of reaction to water supplied from the boiler water nozzle 3, and extract generated steam from the steam outlet nozzle 4.

The operating conditions are such that the reaction temperature is higher than that of a fixed-bed system to prevent the high-boiling products produced by the reaction from adhering to the catalyst surface and increasing its size, which would adversely affect the fluidization state. At a high temperature of 600 to 550°C and a pressure of 20 to 50 at.
I'm driving at m.

As a result, as shown in Table 2, there was a large amount of C,, C, gas, and the olefin content in C8 and C4 was as high as 82%.

The C-fraction is not very high at around 35% of the total organic compounds. It's a trench, so the space velocity is high, so the amount of CO2 produced is low. Among the products, polymerized gasoline made from propylene, butene, etc. is unleaded and has an octane number of 82.

Table 2 Yield of hydrocol method [(Source) Sorch, H, Hoetc: The
Fischer Tropshan4 Re1ate
d Symthesis, Wiley (1951)
] Gas superficial velocity: [L18~020 m/sec Circulating gas ratio: t7 Catalyst diFe system, 40~525 mesb 80% Reactor:
5.05φm s 99 trL3 (catalyst 175~20
ot) As a sixth method for producing hydrocarbons from synthesis gas, Mopil's MTG (Methanol t
.

There is a Ga5oline (hereinafter abbreviated as MTG) method. The process uses two reactors when carried out in a fixed bed type apparatus. The first reactor dehydrates methanol using a dehydration catalyst (alumina type) to produce a compound a of methanol, dimethyl ether, and arsenic.

2 CH,OH−+ CH,OCH3+H20 The second reactor converts oxygenates to hydrocarbons over a ZSM-5 zeolite catalyst.

The reason why the CH,OCR,→2(-CH,-)+H,0 reaction is carried out in two stages is to facilitate the removal of reaction heat, and the total calorific value is removed in the first and second reactors, respectively. 20% and 8
0% fever.

In addition to the C- to CIO hydrocarbons, the product of the second reactor contains a large amount of low-boiling hydrocarbons.

This low boiling point gas is sent again to the second reactor as a circulating gas, and at the same time increases the yield of gasoline through alkylation, it also serves as a heat medium for removing reaction heat. The amount of circulating gas is 7 to 9 times the amount of raw material gas.

In the second reactor, the activity of the catalyst deteriorates due to carbonaceous deposition on the catalyst, requiring catalyst regeneration after approximately 500 hours.

For this reason, a plurality of second reactors are arranged in parallel, and reaction and regeneration are repeated in each reactor. As mentioned above, Kenpo requires a large amount of circulating gas, and when using a fixed bed reactor, it has the disadvantage of having to install multiple reactors and regenerating the catalyst intermittently. .

On the other hand, when carrying out the MTC method using a fluidized bed system,
Methanol and water are vaporized and fed to produce hydrocarbons in a single-stage reactor. The hydrocarbons produced at the top of the reactor and the separated catalyst are circulated between the reactor and a regenerator.

The main equipment of this reactor is a reactor, a separator, and a regenerator, and is basically similar to the circulating fluidized bed reactor for the F to 'r reaction described above. The difference is that the heat exchanger is external, and the sensible heat of the catalyst is removed outside the reactor. Table 6 shows the operational results of the fixed bed type device and fluidized bed type device in the MTC method.

By converting propylene and butenes in the product into alkyl groups with isobutane, the final gasoline yield is 85% in the fixed bed method and 88% in the fluidized bed method, and the octane number of the gasoline is lead-free and at the same level. 96 and 968. Compared to a fixed bed, the catalyst activity of a fluidized bed does not change significantly over time, making it easier to control product distribution. Additionally, the amount of circulating gas can be considerably reduced.

Table 6 Product yield according to MTC) [Source: Harney ate: Hydroca
rbon Process, 2.67 (1980)) Table 6 Table 4 also shows the influence of temperature in a fixed bed type apparatus (MTG method). The higher the reaction temperature, the more C4-C and paraffin content increases, and at 670°C or higher, the olefin content also increases. Butane decreases slightly with increasing temperature, and aliphatic compounds of 04 and above also decrease with increasing temperature. The amount of violet produced due to durene decreases as the reaction temperature increases.

Table 4 Shadow of product by temperature in MTG method # (fixed bed) [(Source) Chang etc: rltc,
Prod, Res, Dev.

17, 255 (1978)) (Note 2) Co or more aromatic (Aromatic)
Regarding hydrocarbon synthesis reactions using carbon monoxide and hydrogen as raw materials, as an example of exothermic reactions, F-T
The results of operation using a fixed bed reactor and a fluidized bed reactor in the Hydrocol method, the Hydrocol method, and Mopil's MTG method were compared and explained. As a result, it became clear that the controllability of the reaction temperature in the reactor greatly influences the yield and composition of the product.

Therefore, in the present invention, as a reactor for a substance that causes an exothermic reaction, the above-mentioned drawbacks are improved, and the reaction temperature is controlled uniformly to produce a high-quality product while at the same time efficiently recovering the reaction heat. This paper proposes a reactor that can do this.

That is, in the present invention, a gas blowing nozzle is provided at the bottom of the reactor, a gas extraction nozzle is provided at the top, a funnel-shaped perforated plate is provided at the bottom, a raw material supply nozzle is provided at the center of the perforated plate, and the same material supply nozzle as the raw material supply nozzle is provided. A reaction tube is provided on the central axis, a heat transfer tube is provided around the reaction tube, a solid-gas separation section is provided above the reaction tube installation section, a solid extraction nozzle is provided in the solid-gas separation section, and a solid-gas separation section is provided above the reaction tube installation section. This invention relates to a reaction device in which a large cyclone is attached above a gas separation section, and a small cyclone is attached inside the large cyclone.

5) and CB) are cross-sectional views showing an outline of one embodiment of the device of the present invention, and FIG. 5(B) is a sectional view of A of FIG.
-=A#! It is an arrow view.

In FIGS. 5(A) and (J3), 20 indicates the main body of the device, and the perforated plate 1 at the bottom of the device is funnel-shaped.
The angle α formed between

α=β+(10~60) (degrees) The angle of repose β of the fluid medium varies depending on the substance, and is approximately 20~45
degree value theal. Example In the case of kldFc c f@t$ (synthetic silica-alumina catalyst) (0,061 m diameter), the angle of repose β is 52 degrees, and α is preferably 40 to 60 degrees.

Note that if the perforated plate 1 is horizontal, the stationary solid Jr. This is not preferable because it causes I (tied zone).

A gas blowing nozzle 2 is provided at the bottom of the reactor below the perforated plate 1 to prevent the fluid medium from accumulating on the perforated plate 1. Raw material supply nozzle 3 is located near the center of the bottom of the reactor.
A reaction tube 4 is provided in the reactor on the same center line as the raw material supply nozzle 3. A heat transfer tube group 5 is provided around the reaction tube 4 to transfer the sensible heat of the solid particles of the fluidized medium that has risen due to the exothermic reaction to the cooling medium flowing inside the heat transfer tube group 5. The solid particles are cooled to a predetermined temperature and
maintained and stable operating conditions can be maintained.

The body diameter D2 of the solid-gas separator 6 in the upper part of the reactor should preferably be 1'0.Do with respect to the inner diameter Do of the reaction tube 4, and if it is smaller than this, solid particles will not be entrained in the gas. There will be more. In addition, the body diameter D1 of the heat transfer tube group installation part at the bottom of the reactor is:
It is determined from the sum of the cross section rfJ building S required for the circulating catalyst to flow down and the required cross sectional area S2 of the heat transfer tube. The above-mentioned glue is determined from the relationship between the above-mentioned glue and the gas flow rate, and generally D2≧D1.

A solid extraction nozzle 7 is attached to the lower part of the solid-gas separation section 6, and a part of the circulating catalyst is continuously discharged to the outside of the system in order to regenerate the deteriorated catalyst.

Further, a large cyclone 8 is attached to the upper part of the solid-gas separation section B, which separates solids entrained in the gas. The inlet gas flow velocity of the large cyclone 8 is 5 to 15 m/sec.
A flow rate of about e is preferable, and if the flow velocity is higher than this, solid wear on the inner wall of the cyclone 8 becomes severe. Therefore, a slit 9 is provided in the side wall of the cyclone 8, and the structure is such that the solids reaching the wall surface are quickly discharged to the outside of the cyclone 8.

The fine particle size solids that are not separated and removed by the large cyclone 8 are further separated from gas by a small cyclone 10 provided inside the large cyclone 8. The flow rate of the log gas entering the small cyclone 100 is preferably 20 to 30 m/see. At the upper part of the small cyclone 10, there is a gas discharge nozzle 1 for discharging the gas after solid-gas separation to the outside of the reactor.
1 is provided.

F-'I' describes the mode of operation of the device of the present invention having the above configuration.
An example of a reaction will be explained.

The lower part of the reactor 20 is filled with catalyst.

The preheated raw material gas (H4-Co) is blown into the reactor 20 from the nozzle 3 and further rises inside the reaction tube 4.

At this time, the charged catalyst is sucked into the reaction tube 4 and moves from the lower part of the reaction tube 4 to the upper part in a homogeneous mixture, during which time an FT reaction occurs to produce hydrocarbons. The heat transfer v4
Gas velocity within #! , U is the terminal rate of catalyst formation from 6 to
4 times is preferable.

The ambient air mixed phase fluid that has passed through the reaction tube 4 moves to the solid-gas separation section 6, which has a wide internal diameter in the center of the reactor 20, where the gas flow rate rapidly decreases, forming a dense fluidized bed, and only the gas is removed. moves to the upper part of the reactor 20 and is separated into solid and gas. Here, the solid-gas separated catalyst descends to the lower part of the reactor, where the heat transfer tube group 5 is provided, while maintaining a fluid state. At this time, the sensible heat held by the catalyst particles is transferred to the cooling medium flowing in the heat transfer tube group 5, and the catalyst particles are cooled. The coolant heated by transferring the sensible heat of the catalyst particles is recovered by another heat exchanger (not shown in the figure).

The state of the dense fluidized bed around the heat transfer tube group 5 is adjusted by the amount of gas blown into the waste blowing nozzle 2 provided at the lower part of the reactor 20 .

In the case of the above FT reaction, the catalyst deteriorates after about 1500 hours of reaction time, so a part of the catalyst is continuously discharged from the solid extraction nozzle 7 and stored in the regenerator (F1?i in the figure). After the regeneration process, it is used repeatedly.

As described above, when the apparatus of the present invention is used in a reaction involving an exothermic reaction, the following effects can be obtained.

(1) Since the heat of reaction can be easily removed, the temperature inside the reaction tube can be maintained uniformly, and as a result, products with stable properties can be continuously produced.

2) The reaction heat recovery rate is high, and the heat can be recovered as high-grade steam.

(3) Since the large cyclone at the top of the reactor allows for solid-gas separation in a mild manner, there is very little wear on the side wall of the cyclone.

(4) Continuous discharge and supply for catalyst regeneration is possible.

(5) It is easy to increase the size of the reactor.

(6) The apparatus shown in Fig. 4 used in the hydrocol method described above is a dense fluidized bed type, and the height of the flow 1jth layer is 2 to 3 r.
I can only get about rL, so I decided to go with M! b) The gas residence time in the WI (necessary contact time between gas and catalyst) is not sufficient, whereas the reaction tube of the present invention is a dilute fluidized bed, so the long residence time required for the reaction is ) can be taken.

Hereinafter, Example ff will be shown to specifically demonstrate the effects of the apparatus of the present invention.

Example 1 An FT synthesis reaction was carried out in the following manner using the apparatus of the present invention having the configuration shown in FIG. 5 and the dimensions shown below.

Inner diameter D0 of reaction tube 4 5D pharyngeal reaction device 20
Lower inner diameter, 260 homogeneous molecules a=V
>6 shell inner diameter D2550tMn inner diameter and length of heat transfer tube 5
・10.5φill
50 degree catalyst Ruthenium catalyst, average particle size 55μ Precise reaction conditions Reaction temperature 295℃ Raw material H2/C
o2. The results obtained in the treatment with an i mol/mol raw material gas amount of 15 filtration and 6 Nm'/h or more were as follows.

CO conversion rate 96. dwt, polyproduced hydrocarbon composition cl 5low wt, % (:21.5 348 C", 1"1.8 C, ~C,.75.5 Cnt 3 Steam recovery lid 10Kg/cm2A steam 112Ky
/h As described above, when the apparatus of the present invention was used, temperature control was easy and stable operation could be performed.

Comparative Example 1 As a result of carrying out the F-T synthesis reaction under the following conditions using a conventional fixed-bed small reactor shown in Fig. 2 with the following dimensions, a temperature distribution within the catalyst layer was produced as shown in Fig. 6. , it was very difficult to control uniform temperature distribution.

Reactor inner diameter 15mm Catalyst filling 1t11 Material supply temperature 265℃ Raw material gas supply i 1. INm”/h (H2/cO=2
．． 0mozo1nol) Reaction pressure 21'! 4/cn
P A catalyst Ruthenium catalyst, average particle size 55μ
It goes without saying that the apparatus of the present invention is preferably applicable not only to the above-mentioned F-'r synthesis reaction but also to reactions by the above-mentioned hydrocol method and M'I'G method.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of the free energy key change in the carbon monoxide water accumulation reaction, Figure 2 is a diagram showing the conventional fixed bed reactor used in the F-T synthesis method, and Figure 3 is also an illustration of the F-T synthesis method. -A diagram showing the conventional fluidized bed reactor used in the τ synthesis method,
Figure 4 shows the conventional #L used in the hydrocol method.
FIG. 5 is a diagram showing an embodiment of the apparatus of the present invention, and FIG. 6 is a diagram showing a moving bed type reactor. 2 is a chart showing an example of the temperature distribution within the catalyst layer in the case of Agents 1) Akira Agent Ryo Hagihara - Figure 1 Figure 2 Figure 3 Figure 4 Garden

Claims (1)

[Claims] A gas injection nozzle is provided at the bottom of the reactor, a gas extraction nozzle is provided at the top, a funnel-shaped perforated plate is provided at the bottom, a raw material supply nozzle is provided at the center of the perforated plate, and the reaction is carried out on the same central axis as the raw material supply nozzle. A tube is provided, a heat transfer tube is provided around the reaction tube,
A solid-gas separation section is provided above the reaction tube installation section, a solid extraction nozzle is provided in the solid-gas separation section, a large cyclone is attached above the solid-gas separation section, and a small cyclone is installed inside the large cyclone. A reaction device equipped with