JP2615424B2 - Falling thin film catalytic reaction method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a reaction method and a reaction apparatus for obtaining a useful product from a reaction product in a liquid phase using a catalyst and heat, and more particularly, to a method for increasing heat using an endothermic / exothermic reaction. The present invention relates to a reaction method and a reaction apparatus in an endothermic process of a temperature technique.

[0002]

2. Description of the Related Art FIG. 4 shows a typical example in the case of performing a decomposition reaction of a liquid phase reactant using a catalyst. In FIG. 4, 1 is a reaction tank, 2 is a distillation tower, 3 is a cooler, Q is supply heat for heating, S is a solution in the reaction tank 1, WP is catalyst particles, and V is a distillation from the reaction tank 1. The vapor entering the column 2, L is a reaction liquid returning from the distillation column 2 to the reaction tank 1, D is a liquid or vapor taken out, and F is a liquid or vapor injected from the outside.

[0003] The catalyst particles WP are used in a state of being suspended in a liquid phase in a reaction tank 1. In the reaction tank 1, a product of a condensable gas or a non-condensable gas is obtained from the liquid phase reactant by the action of the catalyst particles WP and the supply heat Q.

In general, in the case of a liquid phase reaction, all of the reactants rarely react to form a product. When the product accumulates and the chemical equilibrium is reached, the reaction does not proceed. The reaction can be sustained by removing it.
As a means for continuously removing the product, a distillation column capable of separating using a boiling point difference between a reactant and a product is used. Such a method of suspending a catalyst in a liquid phase has an advantage that a contact area between a catalyst and a reactant can be increased by using a powdery catalyst.

[0005]

In order to carry out the catalytic reaction efficiently, it is necessary from a chemical equilibrium point that the product is quickly released from the catalyst surface and the concentration of the product is low around the catalyst. . However, in the above-mentioned conventional method, in order to adopt a method of suspending the catalyst particles WP in the reaction tank 1, the product generated on the surface of the catalyst in the reaction solution rises in the solution S to the gas phase interface. There must be. Therefore, in the catalyst particles WP relatively higher in the solution S, since the products generated by the catalyst particles WP relatively lower in the solution S rise, the concentration of the products around the catalyst particles WP increases. However, the original reaction rate of the catalyst cannot be achieved. Further, in order to promptly drive out the product in the solution S into the gas phase, it is necessary to add a large amount of heat. Therefore, there was a serious problem that the supplied heat Q was not effectively used for the reaction.

It is an object of the present invention to provide a falling thin film catalytic reaction method and apparatus capable of promptly releasing a substance produced by the reaction and improving the reaction rate.

[0007]

SUMMARY OF THE INVENTION According to the present invention, there is provided a falling thin film catalytic reaction method comprising the steps of forming a reactant in a liquid phase into a thin film, bringing the reactant into contact with a catalyst, causing a thermal reaction, and releasing a product from the liquid phase. To obtain the product.

Further, the liquid phase reactant is formed into a thin film by forming a flow path in the inclined catalyst surface.

Further, two or more kinds of catalysts are arranged along the flow path in accordance with the composition of the liquid phase reactant.

Further, the catalyst is a single catalyst or a mixed catalyst.

Further, the falling thin film catalytic reactor according to the present invention comprises a planar catalyst layer, a liquid film reactant formed on the catalyst layer in a thin film and brought into contact with the catalyst to cause a thermal reaction, thereby producing a product. And a liquid-phase reactant supply means for obtaining a product by removing the compound from the liquid phase.

[0012]

The falling thin film catalytic reaction method according to the present invention employs a reaction method in which a reactant in a liquid phase is formed into a thin film and brought into contact with a catalyst, so that a substance produced on the surface of the catalyst can react with the reaction solution. It is possible to pass through a thin membrane in a short time, the product is quickly released from the catalyst surface and its surroundings, the residence time of the product in the reaction solution is short, the reaction speed is improved, and heat is efficiently used Can be achieved.

Further, since the surface of the catalyst is tilted and the liquid phase reactant flows down over the catalyst, the reactant can be easily formed into a thin film.

In the above reaction method, generally,
Since the composition of the liquid phase reactant flowing in a thin film on the catalyst changes along the flow path, a mixed catalyst or a single catalyst capable of performing an optimal reaction with respect to the composition of the liquid phase reactant is obtained. By arranging at least two types of one catalyst along the flow path, it is possible to further improve the reaction rate and efficiently use heat.

Further, the falling thin film catalytic reactor according to the present invention makes the reactant in the liquid phase into a thin film and comes into contact with the catalyst. In a short time, and the residence time of the product in the reaction solution is shortened.

[0016]

FIG. 1 is a schematic sectional view showing an embodiment of a falling thin film catalytic reactor according to the present invention. In the figure, reference numeral 10 denotes a reaction tank, and WL denotes a catalyst layer, which is inclined at an appropriate angle as shown. V is a vapor, L is a thin film-like reaction liquid forming a flow in the flow path, and supply heat Q required for the reaction is
Is supplied evenly or locally from below the catalyst layer WL. Other configurations are the same as those shown in FIG.

Next, the operation will be described. The product generated at the interface between the reaction liquid L and the catalyst layer WL quickly passes through the liquid film and separates into the gas phase as shown by the arrow v, since the reaction liquid L is extremely thin. Therefore, by shortening the time during which the product remains in the liquid phase, the concentration of the product can be kept low on the surface of the catalyst or around the catalyst, thereby improving the reaction rate and efficiently using heat. be able to.

The catalyst layer WL is preferably porous in order to increase the contact area with the reaction liquid L. Further, in order to efficiently use the heat required for the reaction, the material is preferably a material having good heat conductivity.

FIG. 2 shows the ratio of heat (heat utilization rate α) to the supply heat Q when the reactant is 2-propanol and the products are acetone and hydrogen as the reaction system. Are plotted against the acetone concentration (X) of the reaction liquid L in the case of the conventional method shown in FIG. 1 and in the case of the present invention in which the reaction tank 1 in FIG. 4 is replaced with the reaction tank 10 in FIG. The curve I is the conventional one, and the curve II is the one according to the present invention. In this case, the supplied heat Q was uniformly applied to the reactants.

When the acetone concentration in the reaction solution L is 0.25, the heat utilization coefficient α is 0.5 in both cases, but at a concentration lower than this, the method of the present invention has a larger heat utilization coefficient. Obtained and proved to be effective.

The configuration of the reaction apparatus shown in FIG.
Is suitable when the composition of the reaction liquid L is almost constant, but the composition of the reaction liquid L flowing in a thin film shape may change along the flow path. For example, the distillation column 2 in FIG.
This is a case where the function of the reaction tank 10 is provided. In this case,
A configuration as shown in FIG. 3 can be employed. W1 of this figure
W4 is the reaction liquid L that changes along the flow path at each position.
Is a catalyst layer that gives an optimum reaction rate for the composition of
The figure shows the case of four types of catalyst layers.
Any number of species or more is acceptable.

Assuming that the reactant is 2-propanol and the products are acetone and hydrogen, the reaction solution L at the position of the catalyst layer W1 is a solution having a high acetone concentration returned from the condenser. On the other hand, while the reaction liquid L flows down, the easily vaporized acetone escapes to the gas phase, so that the reaction liquid L at the position of the catalyst layer W4 has a low acetone concentration. Therefore, the catalyst layer W1 is a catalyst having a high reaction rate in a place where the acetone concentration is high, and the catalyst layer W4.
, A catalyst having a high reaction rate at a place where the acetone concentration is low is arranged, and an intermediate catalyst between W1 and W4 is arranged in an intermediate region between these. Thus, by arranging the catalyst most suitable for the composition of the reaction liquid L, it becomes possible to configure a reaction tank having a distillation function that cannot be performed by a conventional method of suspending the catalyst and performing the reaction. Effective heat utilization can be achieved.

It is to be noted that more effective heat utilization can be achieved by setting an optimum temperature condition for each position in relation to each catalyst and a change in the composition of the reaction solution as the supply heat Q for heating.

[0024]

The falling thin film catalytic reaction method according to the present invention is characterized in that the reactant in the liquid phase is formed into a thin film and is brought into contact with the catalyst to cause a thermal reaction, thereby releasing the product from the liquid phase to thereby remove the product. As a result, the substance generated on the catalyst surface passes through the thin film of the reaction solution in a short time, so that the reaction speed can be improved and efficient use of heat can be achieved.

Further, since the catalyst surface is inclined and the surface of the catalyst surface is used as a flow path for the liquid phase reactant, the operation is easy.

Further, since two or more kinds of catalysts are provided along the flow path, it is possible to cause an optimal reaction with respect to the composition of the liquid phase reactant.

Further, since at least two kinds of mixed catalysts or single catalysts are arranged along the flow path, a more optimal reaction can be performed.

Further, the falling thin film catalytic reactor according to the present invention comprises a planar catalyst layer, a liquid film reactant formed on the catalyst layer in a thin film, and brought into contact with the catalyst to cause a thermal reaction to produce a product. And a liquid-phase reactant supply means for obtaining a product by separating from the liquid phase, so that the substance generated on the catalyst surface passes through a thin film of the reaction solution in a short time, so that the reaction speed is reduced. It is possible to improve heat efficiency.

As described above, in the conventional method of suspending the catalyst in the reaction tank, the supplied heat is not effectively used for the reaction. However, according to the present invention, the reaction speed is improved and the efficiency is improved. Heat utilization becomes possible. In addition, there is an advantage that a reaction tank having a distillation function can be configured.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of an embodiment of a falling thin film catalytic reactor according to the present invention.

FIG. 2 is a diagram showing a comparison diagram of heat utilization rates between a conventional system and a system according to the present invention.

FIG. 3 is a diagram showing an embodiment to which the present invention is applied.

FIG. 4 is a diagram showing a configuration of a conventional catalyst suspension type reaction tank and a distillation apparatus.

[Explanation of symbols]

 WL Catalyst layer L Reaction liquid V Steam Q Supply heat 10 Reaction tank

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Takahiro Fujii 1-4-1 Umezono, Tsukuba, Ibaraki Pref.

Claims (5)

(57) [Claims] 1. A reaction product in a liquid phase utilizing a catalyst and heat,
A reaction method for obtaining a product of a condensable gas and / or a product of a non-condensable gas. A falling-film catalytic reaction method, wherein a product is obtained by removing the product from the catalyst. 2. The falling thin film catalytic reaction method according to claim 1, wherein the liquid phase reactant is formed into a thin film by forming a flow path on the inclined surface of the catalyst. 3. The falling thin film catalytic reaction method according to claim 2, wherein two or more kinds of catalysts are arranged along the flow path in correspondence with the composition of the liquid phase reactant. 4. The falling thin film catalytic reaction method according to claim 1, wherein the catalyst is a single catalyst or a mixed catalyst. 5. A reaction product in a liquid phase utilizing a catalyst and heat,
A reactor for obtaining a product of a condensable gas and / or a product of a non-condensable gas, comprising: a planar catalyst layer;
A liquid-phase reactant supply means for obtaining a product by bringing the liquid-phase reactant into a thin film on the catalyst layer, contacting the catalyst with the catalyst, causing a thermal reaction, and separating the product from the liquid phase. Characteristic falling-film catalytic reactor.