JP2526404C - - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a catalytic reaction method for effectively utilizing heat energy generated by a chemical reaction. 2. Description of the Related Art Conventionally, a catalytic reactor has been used after uniformly filling a catalyst. The heat collecting medium is input to the outside, and the heat of chemical reaction in the reactor is taken out. This will be described with reference to FIGS. In FIG. 5, reference numeral 10 denotes a catalyst reaction tube, 11 denotes an inlet side, and 12 denotes an outlet side. A and B are reactants, C and D are product substances, X is a catalyst, F is a heat medium substance, and Q is reaction heat. As shown in FIG. 5, a catalyst X is uniformly arranged in a catalyst reaction tube 10. In such a conventional method, a local high-temperature portion occurs in the catalyst reaction tube 10 as shown in the temperature distribution diagram of FIG. Therefore, when heat is taken out by the heat medium substance F in the conventional manner, the outlet temperature of the heat medium substance F is defined by the temperature of the outlet side 12 in the catalyst reaction tube 10, If the temperature exceeds the temperature, heat cannot be supplied to the outside. Therefore, it cannot be said that the reaction heat generated in the catalyst reaction tube 10 is always used effectively. [0005] As described above, in the method and apparatus using the conventional catalyst reaction tube 10 in which the catalyst is uniformly filled, the temperature rises partially in the catalyst reaction tube 10 and the reaction conditions are increased. Is partially changed, and the reaction temperature at the outlet side 12 of the catalyst reaction tube 10 becomes lower than the temperature of the heat medium substance F, so that efficient heat exchange to the outside cannot be performed. Further, there is a problem that an unnecessary reaction by-product is generated due to a partial temperature rise. The present invention has been made in view of the above points, and has as its object to provide a catalytic reaction method capable of performing efficient heat exchange and changing the composition of a reaction product. [0007] A first aspect of the present invention is a catalyst reaction method according to the present invention, wherein at least two kinds of catalysts, a relatively low concentration catalyst and a relatively high concentration catalyst, are used as the reaction catalyst. A catalyst is used and the concentration is changed from the inlet side to the outlet side of the catalyst reaction tube so that the inside of the catalyst reaction tube has a specified temperature distribution. In a second aspect of the present invention, at least two kinds of catalysts, a relatively low concentration catalyst and a relatively high concentration catalyst, are used as the reaction catalyst, and the temperature inside the catalyst reaction tube is regulated. The catalyst reaction tube is arranged so that the concentration is changed from the inlet side to the outlet side of the catalyst reaction tube so as to be distributed, and the composition of the reaction product is made variable according to the reaction conditions. In a third aspect of the present invention, there is provided a catalyst reaction method wherein at least two kinds of catalysts, a relatively low-activity catalyst and a relatively high-activity catalyst, are used as reaction catalysts, and the temperature inside the catalyst reaction tube is regulated. The catalyst reaction tubes are arranged so that their activities are changed from the inlet side to the outlet side of the catalyst reaction tube so as to be distributed. In a fourth aspect of the present invention, at least two types of catalysts, a relatively low activity catalyst and a relatively high activity catalyst, are used as reaction catalysts, and the inside of the catalyst reaction tube is adjusted according to the conditions. Thus, the composition of the reaction product is made variable. According to catalysis how the [0012] the present invention, the catalyst takes the density distribution or composition distribution over the reaction purposes catalytic reaction tube. Therefore, a partial rise in temperature can be prevented, and the reaction heat can be efficiently supplied to the external heat medium substance. Further, unnecessary reaction by-products can be suppressed, and the composition of the reaction products can be controlled. FIG. 1 shows a schematic configuration of a catalytic reaction method according to an embodiment of the present invention in which the concentration distribution of a catalytic reaction tube is optimally arranged. In FIG. 1, the same reference numerals as those in FIG. 5 indicate the same components, and XDL indicates a low concentration catalyst and XDH indicates a high concentration catalyst. For example, with respect to the catalyst used for the acetone hydrogenation reaction, specific examples of the relatively low-concentration catalyst XDL include a catalyst in which a nickel ultrafine particle catalyst is diluted to have a relatively small amount of catalyst per unit volume, and a relatively high-concentration catalyst. Catalyst XD
Specific examples of H include those using a nickel ultrafine particle catalyst without dilution. According to the above configuration, as shown in the temperature distribution diagram of FIG. 4, the temperature of the outlet side 12 of the catalyst reaction tube 10 becomes the highest, and the reaction heat can be more effectively supplied to the outside. Further, unnecessary reaction by-products can be controlled by controlling the temperature distribution. In order to make the temperature distribution in the catalyst reaction tube 10 variable between the low-concentration catalyst XDL and the high-concentration catalyst XDH by using two or more types of catalysts and devising their arrangement, the reaction conditions change. The composition of the products C and D can be changed. Here, the acetone hydrogenation reaction will be described more specifically with reference to FIG. Acetone and hydrogen are used as the reactant A and the reactant B flowing from the inlet side 11 of the catalyst reaction tube 10, and nickel ultrafine particles are used as the catalyst X and diphenyl ether is used as the heat medium material F. An acetone hydrogenation reaction, which is an exothermic reaction, occurs by the catalyst X, and 2-propanol is generated as a product C, and the reaction heat Q (55)
kJ / mol). Since the activity of the low concentration catalyst XDL is low, the heat of reaction Q per unit catalyst volume is small, and the activity of the high concentration catalyst XDH is high. The generation of by-products can be controlled by controlling the temperature condition of each part of the catalyst reaction tube 10 by the catalyst concentration. FIG. 2 shows another embodiment of the catalytic reaction method according to the present invention.
3 shows a schematic configuration in a case where the optimum arrangement of the composition distribution is performed. In FIG. 2, XAL
Is a low activity catalyst, XAH is a high activity catalyst, and the others are the same as those in FIG. What is characteristic in this embodiment is that the temperature distribution in the catalyst reaction tube 10 can be changed according to the arrangement of at least two types of catalysts, the relatively low activity catalyst XAL and the relatively high activity catalyst XAH. is there. Examples of such a catalyst include a palladium catalyst as a specific example of a relatively low-activity catalyst and a ruthenium catalyst as a specific example of a relatively high-activity catalyst with respect to a catalyst used in an acetone hydrogenation reaction. Also, in this embodiment, the composition of the reaction product can be changed because the reaction conditions are changed. For example, with respect to the catalyst used for the acetone hydrogenation reaction, even if the reaction conditions are constant, there is a difference in by-product species due to the difference in selectivity of the reaction in which the catalyst species differs. As a specific example, since the platinum catalyst has a higher activity of hydrogenolyzing acetone than a palladium catalyst, the platinum catalyst is more likely to generate propane as a by-product. FIG. 3 is a schematic diagram showing one embodiment of a catalytic reaction apparatus for performing the catalytic reaction method of the present invention. In FIG. 3, 1 is a first container that contains a reactant A,
2 is a second container containing the reactant B, 3 is a third container containing the heat transfer medium F, 4
Is a fourth container for accommodating the product substances C and D, 5 is a first heat exchanger for transmitting the heat generated in the catalytic reaction tube 10 to the heat medium substance F, and 6 is the heat obtained in the first heat exchanger 5. A second heat exchanger for supplying the target heat radiation target, a channel means 7 for returning the heat medium substance F to the third container 3, and a catalyst reaction tube 10 shown in FIGS. Next, the operation will be described. Reactants A and B are contained in a first container 1 and a second container 2. Each of the reactants A and B is supplied into the catalyst reaction tube 10, where the reactants A and B are converted into the products C and D by the catalyst X and stored in the fourth container 4. The heat medium substance F is supplied from the third container 3 to the first heat exchanger 5 in order to recover the reaction heat Q generated during the reaction. After recovering the heat generated by the chemical reaction in the first heat exchanger 5, the heat medium substance F performs heat exchange in the second heat exchanger 6 so as to apply heat to the heat radiation target, and is returned to the third container 3. If a device for separating the products C and D is provided between the catalyst reaction tube 10 and the fourth container 4, the products C and D can be stored separately. In the present invention, by disposing at least two types of catalysts having different activities, the temperature distribution in the catalyst reaction tube 10 is controlled to obtain a temperature distribution as shown in FIG. The reaction heat generated in the above can be more effectively supplied to the outside. Further, unnecessary reaction by-products can be suppressed by controlling the temperature distribution. Incidentally, in the acetone hydrogenation reaction as one embodiment of the present invention, if the temperature distribution shown in FIG. It is not preferable from the viewpoint of suppression. Therefore using <br/> the catalysis how according to the invention prevents partial temperature rise by lowering the catalyst concentration in the vicinity of the inlet side 11, increasing the amount of heat generated by increasing the catalyst concentration according to the reactant flow proceeds I do. Thereby, it is possible to take a temperature distribution such that heat transfer from the catalytic reaction tube to the heat medium material always occurs. In one embodiment of the present invention, in the acetone hydrogenation reaction, the equilibrium conversion decreases as the reaction temperature increases. Therefore, when the reaction temperature is too high, the calorific value decreases and the amount of unreacted substances increases. In this case, it is necessary to obtain a large amount of heat while maintaining a high conversion, and the catalytic reaction method according to the present invention is also effective for achieving uniform heat generation. In this case, unlike the temperature distribution shown in FIG. 4, it is necessary to arrange the catalyst so that the temperature distribution in the catalyst reaction tube is made as uniform as possible. In accordance with the principles of the present invention, the reactants need not necessarily be of the A and B types, and the produced materials need not be of the C and D types. As long as there is at least one kind of reactant and at least one kind of product, the temperature distribution desired for the reaction can be determined by applying the principle of the present invention. Further, by selecting three or more types of catalyst concentrations or types of catalyst, it is possible to determine a more finely divided temperature distribution. The temperature distribution inside and outside the catalytic reactor can be determined by applying the principle of the present invention not only to the tubular catalytic reactor 10 but also to a flat catalytic reactor. According to the catalytic reaction method of the present invention, as a reaction catalyst, a relatively low concentration catalyst and a relatively high concentration catalyst, or a relatively low activity catalyst and a relatively high activity catalyst are used. Since at least two types of active catalysts are used, the temperature distribution in the catalyst reaction tube can be controlled as specified, so that the heat of reaction due to the catalytic chemical reaction can be effectively used, and the by-products can be suppressed. Can also have. Therefore, a very desirable result can be obtained in the operation of the chemical reaction process.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram showing a catalyst reaction tube for explaining one embodiment of a catalyst reaction method of the present invention. FIG. 2 is a schematic configuration diagram of a catalyst reaction tube for explaining another embodiment of the catalyst reaction method of the present invention. FIG. 3 is a schematic configuration diagram showing one embodiment of a catalytic reaction device for performing the catalytic reaction method of the present invention. FIG. 4 is a diagram showing an example of a temperature distribution obtained by the present invention. FIG. 5 is a schematic configuration diagram showing an example of a catalyst reaction tube of a conventional catalyst reaction device. FIG. 6 is a diagram showing an example of a temperature distribution in a conventional catalyst reaction tube. [Description of Signs] 1 First container 2 Second container 3 Third container 4 Fourth container 5 First heat exchanger 6 Second heat exchanger 10 Catalyst reaction tube 11 Inlet side 12 Outlet side X catalyst XDL Low concentration catalyst XDH High concentration catalyst XAL Low activity catalyst XAH High activity catalyst

Claims (1)

Claims: 1. A catalytic reaction method in which heat energy generated in a catalytic reaction tube by an exothermic reaction using a reaction catalyst is absorbed by a heat medium substance, wherein the reaction catalyst has a relatively low concentration. Using at least two types of catalysts, a catalyst and a catalyst having a relatively high concentration, the temperature distribution in the catalyst reaction tube is increased from the reaction tube inlet to the reaction tube outlet so that the reaction tube outlet temperature becomes the maximum temperature. Wherein the concentration is changed from the inlet side to the outlet side of the catalyst reaction tube. 2. A catalytic reaction method in which a heat medium material absorbs heat energy generated in a catalytic reaction tube by an exothermic reaction using a reaction catalyst, wherein the reaction catalyst has a relatively low concentration of catalyst and a relatively high concentration of catalyst. Using at least two kinds of catalysts, the temperature distribution in the catalyst reaction tube is increased from the reaction tube inlet to the reaction tube outlet, and the entrance of the catalyst reaction tube is set so that the reaction tube outlet temperature becomes the maximum temperature. A catalytic reaction method characterized in that the concentration is changed from the side to the outlet side, and the composition of the reaction product is variable according to the reaction conditions. 3. A catalytic reaction method in which heat energy generated in a catalytic reaction tube by an exothermic reaction using a reaction catalyst is absorbed by a heat medium material, wherein the reaction catalyst has a relatively low activity and a relatively high activity. Using at least two types of active catalysts, the temperature distribution in the catalyst reaction tube is increased from the reaction tube inlet to the reaction tube outlet, and the catalyst reaction tube is controlled so that the reaction tube outlet temperature becomes the maximum temperature. A catalytic reaction method wherein the activity is changed from the entrance side to the exit side. 4. A catalytic chemical reaction method in which heat energy generated in a catalytic reaction tube by an exothermic reaction using a reaction catalyst is absorbed by a heat medium material, wherein the reaction catalyst is a relatively low activity catalyst. Using at least two kinds of high activity catalysts, the temperature distribution in the catalyst reaction tube is increased from the reaction tube inlet to the reaction tube outlet, and the catalyst reaction is performed so that the reaction tube outlet temperature is the highest temperature. A catalytic reaction method, wherein the activity is changed from the inlet side to the outlet side in a tube, and the composition of the reaction product is variable according to the reaction conditions.