JPH0755287A - Chemical heat pump system - Google Patents

Abstract

PURPOSE:To obtain a high temperature heat source of 200-350 deg.C having a high utilization value from a low temperature heat source of 65 deg.C or lower having a low utilization value in a high efficiency without necessity of a compressor. CONSTITUTION:A chemical heat pump system has in combination an exothermic reaction for generating methyl formate by dehydrogenation condensing methanol and an endothermic reaction for generating methanol by hydrogenating methyl formate. The system comprises an exothermic reactor 1 for conducting the exothermic reaction at a higher pressure than a pressure of the endothermic reaction, an endothermic reactor 6 for conducting the endothermic reaction, and a distillation column 3 for separating effluents from the reactors 1, 6 to methyl formate and hydrogen fractions at a top of the column and methanol fraction at a bottom of the column. Further, the system comprises a heat exchanger 5 for heat exchanging the effluent of the reactor 1 with that of the reactor 6.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a chemical heat pump system utilizing a reversible endothermic / exothermic reaction of an organic compound. More specifically, an endothermic reaction for condensation dehydrogenation of an organic compound and an exothermic reaction for hydrogenating the obtained condensation dehydrogenation product to generate the original organic compound are combined to produce waste heat from a factory, geothermal heat or cogeneration. 50-1
The present invention relates to a chemical heat pump system that converts a relatively low temperature heat source of 00 ° C. into a heat source of high utility value of 200 to 350 ° C.

[0002]

2. Description of the Related Art In recent years, as a means of energy saving or as one of the solutions to the problem of environmental pollution, a heat pump, which converts a low-value low-temperature heat source into a high-value high-temperature heat source to increase the utility value of energy, has been attracting attention. There is.

The heat pump is roughly classified into a compression heat pump that uses mechanical energy and a chemical heat pump that uses a chemical reaction. Since the compression heat pump requires a large amount of work for compressing vapor, it improves COP. There are limits, and there are limits to the heat source used and the temperature level of heat that can be recovered.

COP (Coefficient of Performan)
ce: coefficient of performance) is a coefficient representing the efficiency of the heat pump and is defined by the ratio (Q / W) of the recovered heat energy Q and the given mechanical energy W. However, W is due to the work of the compressor used for the transformation operation to make the equilibrium of the chemical reaction advantageous, and the condensation of the gas for separation, etc., and for the pump used only for circulating the fluid. It does not include work-related items.

On the other hand, a heat pump utilizing a chemical reaction,
In particular, in a chemical heat pump utilizing a reversible endothermic / exothermic reaction of an organic compound, it is possible to obtain a high COP because the mechanical energy for driving the system is small. Moreover, the application of the chemical heat pump system can be expanded by selecting an organic compound suitable for the type of heat source used, its temperature level, and the temperature level of heat that can be recovered and the endothermic / exothermic reaction associated therewith.

So far, reversible heat absorption of organic compounds
As a chemical heat pump utilizing exothermic reaction, 2-
A 2-propanol / acetone-hydrogen chemical heat pump that combines a propanol dehydrogenation reaction and an acetone hydrogenation reaction is disclosed in Japanese Patent Application Laid-Open No. 61-116252 and the like, in which a cyclohexane dehydrogenation reaction and a benzene hydrogenation reaction are performed. Combined cyclohexane / benzene / hydrogen chemical heat pumps have been proposed in JP-A-61-208474 and the like.

It is said that the 2-propanol / acetone-hydrogen type chemical heat pump can obtain a high temperature heat source of 150 to 200 ° C. by utilizing a low temperature heat source of 50 to 120 ° C. Further, in the cyclohexane / benzene-hydrogen chemical heat pump, a low temperature heat source of 200 to 250 ° C is used, and a high temperature heat source of 250 to 400 ° C is obtained by setting the pressure of the exothermic reactor to 10 to 20 kg / cm ^2. It is supposed to be. As far as the inventors know, other than the above-mentioned two systems, satisfactory results have not yet been obtained as a chemical heat pump system.

[0008]

In the above-mentioned 2-propanol / acetone / hydrogen chemical heat pump,
When the pressure of the exothermic reactor is set to normal pressure, the upper limit of the temperature of the recovered heat energy is limited to about 200 ° C. In order to obtain a higher temperature, it is necessary to increase the pressure of the exothermic reactor, and in order to do so, vapor must be compressed by a compressor and fed into the exothermic reactor, resulting in a decrease in COP. To do. Further, even in the endothermic reactor, a sufficient conversion rate cannot be obtained unless the temperature is 80 ° C. or higher, so that the efficiency of pumping energy becomes low.

On the other hand, even in a cyclohexane / benzene / hydrogen chemical heat pump, it is necessary to maintain the pressure of the exothermic reactor at 10 to 20 kg / cm ² for the same reason, and therefore, in the above-mentioned JP-A-61-208474. For that purpose, an expensive hydrogen storage alloy is used, and therefore there is a cost disadvantage. In addition, 10-2 without using hydrogen storage alloy
If a pressure of 0 kg / cm ² is to be obtained, a compressor will be used, and the COP will decrease. Further, if the pressure of the exothermic reactor is increased, not only the compressor is required, but also the manufacturing cost of the exothermic reactor and its peripheral equipment and the maintenance and inspection cost of the compressor are increased, which is economically disadvantageous.

The conventional chemical heat pump system is
In order to have such technical and economic problems,
The reality is that it has not been put to practical use. The present invention is
It was made in view of the problems of the conventional chemical heat pump system described above, and it is possible to use a low-temperature heat source of less than 80 ° C., which has low utility value, without using a compressor or the like.
An object is to provide an economical chemical heat pump system capable of obtaining a high temperature heat source of 00 ° C. or higher with a high COP.

[0011]

Means and Actions for Solving the Problems The present inventors have
As a result of intensive research and experimentation on the selection of organic compounds used in chemical heat pumps utilizing endothermic / exothermic reversible reactions and the system using them, methanol and its condensation dehydrogenation product methyl formate were selected as organic compounds. , An endothermic condensation dehydrogenation reaction that produces methyl formate and hydrogen from methanol and its inverse reaction, an exothermic hydrogenation reaction that produces methanol from methyl formate and hydrogen, are combined, and in the system, the above endothermic condensation dehydrogenation reaction is performed. By providing an endothermic reactor for carrying out the above, an exothermic reactor for carrying out the above-mentioned exothermic hydrogenation reaction, and a distillation column for preliminarily separating undesired components for the reaction in these reactors from the inflow to be introduced into both reactors, The inventors have found that the object of the present invention can be achieved and completed the present invention.

Accordingly, the present invention is a chemical heat pump system combining an endothermic reaction for dehydrogenating methanol to produce methyl formate and an exothermic reaction for hydrogenating methyl formate to produce methanol. Endothermic reactor for carrying out the above, an exothermic reactor for carrying out the above exothermic reaction, and distillation for separating the effluent from the endothermic reactor and the exothermic reactor into a methyl formate and hydrogen fraction at the top of the column and a methanol fraction at the bottom of the column. A column, and both the effluent from the endothermic reactor and the effluent from the exothermic reactor are introduced into the distillation column, and the top methyl formate and hydrogen fraction obtained are introduced into the exothermic reactor. At the same time, a chemical heat pump system is provided, in which a bottom methanol fraction is introduced into the endothermic reactor.

The chemical heat pump performs an endothermic reaction at a low temperature, and an exothermic reaction, which is the reverse reaction thereof, is performed at a temperature higher than the temperature of the endothermic reaction, so that a low-value heat source such as waste heat having a low utility value is used. The purpose is to convert it into a high temperature heat source and recover it.

From the purpose, in the organic compound used in the chemical heat pump, the endothermic reaction easily proceeds at a low temperature, while the exothermic reaction of the product easily proceeds at a high temperature, and It is required that side reactions other than reversible endothermic / exothermic reactions do not occur easily.

In order to satisfy the above requirements, the present inventors have
The reversible reaction of methanol with methyl formate and hydrogen as shown in the following formula 1 was utilized in the chemical heat pump according to the present invention. 2CH ₃ OH = HCOOCH ₃ + 2H ₂ + ΔH (Equation 1) ΔH = 9.6 kcal / mol

Generally, in the reaction equation, the reaction substance is written on the left side and the produced substance is written on the right side. The value of the heat of reaction written in the reaction equation is that the reaction proceeds from the left side to the right side of the reaction equation. Represents the resulting enthalpy change. In case of endothermic reaction, enthalpy increases, so Δ
H is positive.

FIG. 1 shows a change in equilibrium composition with respect to temperature of a methanol / methyl formate / hydrogen system at atmospheric pressure in comparison with a 2-propanol / acetone / hydrogen system shown in the following reaction formula 2. (CH ₃ ) ₂ CHOH = (CH ₃ ) ₂ CO + H ₂ + ΔH (Equation 2) ΔH = 10.4 kcal / mol

In the figure, the solid line including the + mark with the reference numeral (1) indicates methanol / methyl formate / hydrogen system, and the solid line including the square mark with the reference sign (2) indicates 2-propanol / acetone / hydrogen system. . The vertical axis represents the conversion rate of the reactant in the equilibrium state from the left side to the right side in the equations 1 and 2.

A general organic compound system causes an endothermic reaction in a high temperature region and an exothermic reaction in a low temperature region. On the other hand, the system of methanol / methyl hydrogen formate used in the present invention has a high temperature range of 2% as shown in FIG.
-It is possible to carry out the exothermic reaction with an advantageous conversion rate as compared with the propanol / acetone / hydrogen system, while 2-propanol /
It is possible to carry out the endothermic reaction at an advantageous conversion rate as compared with the acetone-hydrogen system.

To further explain, in the system of methanol / methyl hydrogen formate, the reaction of Formula 1 proceeds from left to right at about 9% conversion at 65 ° C. This shows that in the temperature range of 80 ° C., the endothermic reaction proceeds at a conversion rate that is economically sufficiently acceptable. By the way, this conversion rate is 2-
It is the same as when using propanol / acetone / hydrogen system at 100 ° C.

Also, at 250 ° C., the reaction of equation 1 proceeds from right to left at a conversion of about 56%. This indicates that the exothermic reaction proceeds at an economically acceptable conversion rate in the high temperature region. By the way, this conversion rate is 2
-Equivalent to 200 ° C in propanol / acetone / hydrogen system.

Due to the reaction characteristics of the methanol / methyl formate / hydrogen system described above, the present invention provides thermal energy of about 50 to 100 ° C., particularly 65 ° C. or less, of 200 to 350.
It is possible to convert it into heat energy having a high utility value of about ℃, especially 250 ℃ or more.

Further, since the 2-propanol / acetone / hydrogen system is disadvantageous in the exothermic reaction proceeding from the right side to the left side of the formula 2 at about 220 ° C. or higher, the exothermic reaction is efficiently proceeded at a high temperature of about 220 ° C. or higher. , It is difficult to recover that heat. That is, Fig. 1 shows that as long as this system is operated at normal pressure,
It shows that the heat around 100 ° C. can only be converted into the heat at a temperature up to a little 200 ° C.

As described above, the methanol / methyl formate / hydrogen system adopted in the present invention is an endothermic condensation dehydrogenation reaction at a desired temperature range under normal pressure, as compared with the conventionally proposed system of organic compounds. And vice versa, it has a remarkable advantage that the exothermic hydrogenation reaction proceeds at an economical conversion rate. As will be described with reference to the accompanying drawings in a configuration example described later, the chemical heat pump system according to the present invention is configured to make the most of this advantage.

For both endothermic reaction and exothermic reaction, the conversion rate is increased,
In order to suppress side reactions, it is important not to let hydrogen and methyl formate flow into the endothermic reactor and methanol into the exothermic reactor. The distillation column separates the unreacted methanol flowing out from the endothermic reactor to prevent it from flowing into the exothermic reactor, and also separates the unreacted methyl formate and hydrogen flowing out from the exothermic reactor. It is provided to suppress the flow into the endothermic reactor.

In the present invention, the methyl formate and hydrogen fraction at the top of the distillation column contain methyl formate and hydrogen as the main components and a small amount of methanol, and the methanol fraction at the bottom of the column contains methanol as the main component. And contains a small amount of methyl formate. The desired degree of separation in the distillation column should be realized engineering enough by setting the design conditions and operating conditions of the distillation column in consideration of the temperature of the given heat source, the amount of heat or the temperature of heat to be recovered. You can

The reaction temperature of the endothermic reactor is preferably as high as possible in the temperature range of the heat source that can be used, in order to increase the conversion rate and the reaction rate. The lower limit of the endothermic reaction temperature may be any temperature as long as the reaction proceeds from the left side to the right side in the formula 1, but in order to obtain an economical conversion rate, it is preferably 50 ° C. or higher, more preferably 65 ° C. or higher.

The reaction temperature of the exothermic reactor is set to the desired temperature of the heat to be recovered. The lower the temperature, the higher the amount of heat that can be recovered, and the higher the temperature, the lower the amount of heat that can be recovered. Therefore, the reaction temperature is set according to the purpose of using the recovered heat. Since the upper limit temperature is the upper limit of the temperature range in which the reaction proceeds from the right side to the left side in Formula 1, it is 500 ° C. or lower, preferably 400 ° C. or lower, and more preferably 350 ° C. or lower according to FIG. Further, the temperature of the mixture of methyl formate and hydrogen introduced into the exothermic reactor is preferably as high as possible in order to increase the amount of heat recovered.

When the temperature of the overhead condenser of the distillation column is lowered, the proportion of methanol in the mixture introduced into the exothermic reactor is lowered, which is advantageous for the hydrogenation exothermic reaction, but the heat loss from the condenser is reduced. growing. Conversely, increasing the temperature of the condenser increases the proportion of methanol in the mixture introduced into the exothermic reactor, which is disadvantageous for the exothermic hydrogenation reaction, but reduces the heat loss from the condenser.

The temperature of the mixture introduced into the distillation column can be changed by setting the operating conditions of the heat exchanger or by providing a reboiler. Increasing this temperature lowers the proportion of methyl formate in the mixture fed to the endothermic reactor, which is advantageous for the dehydrogenation endothermic reaction, but increases the heat loss from the condenser. Conversely, lowering this temperature increases the proportion of methyl formate in the mixture fed to the endothermic reactor, which is disadvantageous for the dehydrogenative endothermic reaction, but reduces heat loss from the condenser.

The temperature conditions such as the temperature of the overhead condenser, the temperature of introduction into the exothermic reactor, and the temperature of supply to the distillation column described above are set to optimum conditions through economic calculation.

Further, preferably, a heat exchanger for exchanging heat with each of the inflows is provided in order to recover heat from the outflow of the endothermic reactor and the outflow of the exothermic reactor, if necessary. , Improve the thermal efficiency in the chemical heat pump system.

In the present invention, the pressure of the endothermic reactor is usually set higher than the pressure of the exothermic reactor, for example, the exothermic reactor is set to normal pressure and the endothermic reactor is set to slightly higher pressure. The fluid thereby enters the distillation column from the endothermic reactor and further into the exothermic reactor from the top of the distillation column due to the pressure differential.
When a heat exchanger is installed in the middle of the route to recover heat, the pressure difference in the heat exchanger is also taken into consideration to determine the pressure difference. Therefore, the chemical heat pump system of the present invention is
It is possible to eliminate the need for providing a compressor for compressing vapor as in the conventional chemical heat pump system.

In order to introduce the effluent from the exothermic reactor into the endothermic reactor through the distillation column, the effluent is cooled by a heat exchanger or the like to be liquefied, and then pumped in for circulation. preferable. Since the power used to drive this pump is used to transfer the liquid, its work is small and does not contribute to the COP described above.

[0035]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in more detail based on a configuration example with reference to the accompanying drawings. Configuration Example FIG. 2 shows a configuration example of the chemical heat pump system according to the present invention. In this configuration example, in the endothermic reactor 1, the heat is absorbed from the external heat source 1A to perform the endothermic dehydrogenation reaction of methanol. The produced mixture of methyl formate and hydrogen and unreacted methanol is sent to the mixer 2 through the line 7, where the mixture of methanol and unreacted hydrogen and methyl formate from the line 13 (described later) After mixing, they are introduced into the distillation column 3 through the line 8, where they are separated into a methyl formate and a hydrogen fraction and a methanol fraction, and distilled at the top and the bottom, respectively.

The distillation column 3 is equipped with a condenser 4 at the top of the column, which cools and condenses the top fraction, and performs necessary reflux. The mixture of hydrogen and methyl formate and a small amount of methanol flowing out from the top of the column is heated from line 10 via heat exchanger 5, and then introduced into exothermic reactor 6 via line 11. In the exothermic reactor 6, methyl formate is hydrogenated and converted to methanol. This hydrogenation reaction is an exothermic reaction, and the generated heat is supplied to the outside through an appropriate heat transfer means 6A.

The produced methanol and unreacted hydrogen and methyl formate are cooled from the line 12 through the heat exchanger 5, and then sent to the mixer 2 through the line 13. Distillation tower 3
Methanol and a small amount of methyl formate separated in
It is returned to the endothermic reactor 1 through the line 9 from the bottom of the distillation column 3. Therefore, the dehydrogenation reaction of methanol is performed again, and the same route and reaction process are circulated thereafter.

In the present structural example, the mixer 2 is a means for mixing the streams that join from the two lines, and no special one is required as long as it can mix the joined fluids. Also, known devices can be used for the reactors 1 and 6 other than the mixer, the distillation column 3, the heat exchanger 5, and the like.

In this structural example, the fluid is the endothermic reactor 1
Since it flows through the distillation column 3 to the exothermic reactor 6 including the heat exchanger 5 on the way due to the pressure difference, no compressor is required. A pump for feeding the fluid to the endothermic reactor 1 is installed in the line 9 connected to the bottom of the distillation column 3 and the line 13 extending from the heat exchanger 5 to the mixer 2. Also,
The description of parts that are not directly related to the present invention, such as the reflux pump of the distillation column and the tank for receiving the overhead fraction, is omitted.

Examples will be shown below for illustrating the present invention in more detail, but the present invention is not limited to these examples. The example shown below is based on Simulation S
ciences Inc. process simulation software PRO /
This is the result of a simulation performed using II. The equilibrium composition shown in Fig. 1 was also calculated by PRO / II. The actual reaction is carried out by filling the reactor with the catalyst, so that it is also affected by the performance of the catalyst. However, in this example, the reaction is performed according to the chemical equilibrium because it is for clarifying the performance of the process. I decided to proceed.

Example 1 The chemical heat pump system having the configuration example shown in FIG. 2 was simulated under the following conditions. [Simulation setting conditions] Number of stages of distillation column 3: 10 stages Supply amount of methanol to endothermic reactor 1: 100 kg-mol / H
r Endothermic reactor 1 and exothermic reactor 6 pressures: normal pressure Endothermic reactor 1: 65 ° C Exothermic reactor 6: 200 ° C Condenser 4: 20 ° C Mixture introduced into exothermic reactor 6 via line 11: 1
90 ° C

The simulation was conducted assuming that there was no heat loss in each reactor, heat exchanger, line and distillation column. The simulation results are shown in Tables 1 and 2. Heat of 65 ℃ to the endothermic reactor 0.6703 × 10 ⁶ kcal / Hr
It can be seen that the heat of 200 ° C. can be recovered from the exothermic reactor by 0.0322 × 10 ⁶ kcal / Hr by charging.

Example 2 The chemical heat pump system having the configuration example shown in FIG. 2 was simulated under the same conditions as in Example 1 except for the following conditions. Exothermic reactor 6: 250 ° C

The simulation results are shown in Tables 1 and 2. Heat of 65 ° C. is transferred to the endothermic reactor at 0.6351 × 10 ⁶ kc
It is understood that the heat of 250 ° C. can be recovered by 0.0315 × 10 ⁶ kcal / Hr from the exothermic reactor by introducing al / Hr.

Example 3 The chemical heat pump system having the configuration example shown in FIG. 2 was simulated under the same conditions as in Example 1 except for the following conditions. Exothermic reactor 6: 300 ° C

The simulation results are shown in Tables 1 and 2. Heat of 65 ℃ to the endothermic reactor 0.5853 × 10 ⁶ kc
It is understood that the heat of 300 ° C. can be recovered from 0.0282 × 10 ⁶ kcal / Hr from the exothermic reactor by introducing al / Hr.

Example 4 The chemical heat pump system of the configuration example shown in FIG. 2 was simulated under the same conditions as in Example 1 except for the following conditions. Exothermic reactor 6: 350 ° C

The simulation results are shown in Tables 1 and 2. Heat of 65 ° C. to the endothermic reactor 0.5220 × 10 ⁶ kc
It is understood that the heat of 350 ° C. can be recovered from 0.0232 × 10 ⁶ kcal / Hr from the exothermic reactor by introducing al / Hr.

[0049]

[Table 1]

[0050]

[Table 2]

Comparative Example 1 The chemical heat pump system having the configuration example shown in FIG. 2 was simulated under the following conditions using a 2-propanol / acetone-hydrogen system. [Simulation setting conditions] Number of stages of distillation column 3: 10 stages Supply amount of 2-propanol to endothermic reactor 1: 100 kg
-mol / Hr Pressure of endothermic reactor 1 and exothermic reactor 6: both are normal pressure Endothermic reactor 1: 65 ° C Exothermic reactor 6: 200 ° C Condenser 4: 40 ° C

As a result of the simulation, it was found that the endothermic reaction hardly progressed in the endothermic reactor, and that the 2-propanol / acetone-hydrogen system did not function as a chemical heat pump when the endothermic reactor was at 65 ° C.

Comparative Example 2 With respect to the chemical heat pump system having the configuration example shown in FIG. 2, a simulation was performed under the same conditions as in Comparative Example 1 except for the following conditions. Endothermic reactor 1: 80 ° C

The simulation results are shown in Tables 3 and 4. In the 2-propanol / acetone / hydrogen system, 80 ℃ of heat is input to the endothermic reactor at 0.8416 × 10 ⁶ kcal / Hr, so that the heat of 200 ℃ is 0.0 from the exothermic reactor.
It can be seen that 438 × 10 ⁶ kcal / Hr can be recovered.

[0055]

[Table 3]

[0056]

[Table 4]

[0057]

INDUSTRIAL APPLICABILITY The present invention combines an endothermic reaction for dehydrogenative condensation of methanol to produce methyl formate and an exothermic reaction for hydrogenating methyl formate to produce methanol, and an influent for flowing into each reactor. Undesired components are separated in advance in a distillation column, and a fluid is flowed from the endothermic reactor to the exothermic reactor through the distillation column due to a pressure difference, so that a low utility value of 50 to 100 is achieved without a compressor.
℃, especially 200 ℃ from low temperature heat source below 65 ℃
We have realized an economical chemical heat pump system that can obtain a high-temperature heat source of about 350 to 350 ° C with high efficiency.

[Brief description of drawings]

FIG. 1 is a diagram showing a change in equilibrium composition with respect to temperature of methanol and methyl formate at normal pressure in comparison with a change in equilibrium composition of 2-propanol and acetone.

FIG. 2 is a flow sheet of a configuration example of a chemical heat pump system according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Endothermic reactor 2 Mixer 3 Distillation column 4 Condenser 5 Heat exchanger 6 Exothermic reactor 7 to 13 This is a line connecting each device, and each component flows in the direction of the arrow.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Junichi Ito 1134-2, Gongendo, Satte City, Saitama Prefecture Inside the Research and Development Center, Cosmo Research Institute Co., Ltd. (72) Takashi Yoshizawa, 1134-2, Gongendo, Satte City, Saitama Prefecture Cosmo Research Institute R & D Center (72) Inventor Hiroshi Tsuchida 1134-2 Gongendo, Satte City, Saitama Cosmo Research Institute R & D Center

Claims (3)

[Claims] 1. A chemical heat pump system combining an endothermic reaction for dehydrogenating methanol to produce methyl formate and an exothermic reaction for hydrogenating methyl formate to produce methanol, wherein the endothermic reaction is performed. A reactor, an exothermic reactor for carrying out the exothermic reaction, and a distillation column for separating the effluent from the endothermic reactor and the exothermic reactor into a methyl formate and hydrogen fraction at the top of the column and a methanol fraction at the bottom of the column. The effluent from the endothermic reactor and the effluent from the exothermic reactor are both introduced into the distillation column, and the top methyl formate and hydrogen fraction obtained by introducing the distillate into the exothermic reactor and A chemical heat pump system, wherein a methanol fraction is introduced into the endothermic reactor. 2. The chemical heat pump system according to claim 1, further comprising a heat exchanger for exchanging heat between the effluent of the endothermic reactor and the effluent of the exothermic reactor. 3. The chemical heat pump system according to claim 1, wherein the endothermic reactor performs the endothermic reaction at a pressure higher than the pressure of the exothermic reaction in the exothermic reactor.