JP2002168132A - Heat recovery and heat utilization using chemical energy of methanol and methyl formate, and method for generating power - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method efficiently recovering heat and enhancing the utilization of heat from the standpoint of a device cost and an operation cost in a conversion system of heat energy and chemical energy using the decomposition reaction of methanol and methyl formate and the synthetic reaction of methanol and methyl formate. SOLUTION: Heat is recovered by liquid phase decomposition reaction (endothermic reaction) of methanol and methyl formate, then power is generated with an expansion turbine by using decomposition product gas, and heat of liquid phase synthetic reaction of methanol and methyl formate (exothermic reaction) is utilized.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for recovering and utilizing heat and power generation of industrial waste heat and the like discharged from power plants, steelworks and various kinds of process equipment using chemical energy.

[0002]

2. Description of the Related Art Conventionally, as a method of recovering, transporting and using thermal energy, a method using steam or hot water is generally used. However, these methods are greatly restricted in terms of heat loss and equipment cost, and there is a limit in recovering low-temperature exhaust heat. In other words, energy saving is progressing in recent years in various energy-consuming industrial facilities such as power plants and steelworks, and a considerable part of exhaust heat recovery is performed. Because of the lack of means for proper use, they are often discarded, which requires a large cooling load.

[0003] In recent years, as a method of effectively recovering low-temperature exhaust heat and using it for district heating and cooling, hot water supply, and the like in cities, conversion of heat energy into chemical energy for heat recovery and heat utilization has been studied. This method requires the conversion of heat energy and chemical energy on the heat recovery side and heat utilization side, but it can be transported and stored over long distances, has no heat loss during transport and storage, and has a large energy density. This method is also advantageous in terms of equipment costs.

The most prominent thermal energy and chemical energy conversion systems are the methanol and methyl formate decomposition reactions of formulas (1) to (3) and the methanol and methyl formate synthesis reactions of formulas (4) to (6). A method to be used has been proposed (Japanese Patent Publication No. 6-32).
No. 3684). CH ₃ OH → 2H ₂ + CO (1) 2CH ₃ OH → 2H ₂ + HCOOCH ₃ (2) HCOOCH ₃ → CH ₃ OH + CO (3) 2H ₂ + CO → CH ₃ OH (4) 2H ₂ + HCOOCH ₃ → 2CH ₃ OH (5) CH ₃ OH + CO → HCOOCH ₃ (6) This method is an endothermic reaction of methanol and methyl formate represented by the formulas (1) to (3). Heat recovery is performed using the formula, the obtained carbon monoxide and hydrogen are transported, and heat energy is supplied by the exothermic reaction of methanol and methyl formate of formulas (4) to (6) on the heat utilization side. The methanol and methyl formate generated by the equations (4) to (6) are recycled to the heat recovery side.

[0005]

The conversion system using the formulas (1) to (6) can easily carry out the reaction using methanol and methyl formate which are inexpensive and easy to handle. However, it has the following problems. (A) The heat recovery is restricted by the lower limit temperature of the decomposition reaction of methanol and methyl formate in the formulas (1) to (3). From a practical viewpoint such as the reaction rate, the lower limit temperature of the heat recovery is around 200 ° C. Is the limit. On the other hand, (1) ~
It is necessary to lower the reaction temperature of formula (3), but (1) to (3)
The chemical equilibrium relation of the reaction of the formula becomes significantly disadvantageous on the decomposition side as the reaction temperature decreases and the reaction pressure increases. (B) From the viewpoint of heat utilization, it is advantageous to carry out the methanol and methyl formate synthesis reactions of the formulas (4) to (6) at a high temperature.
The chemical equilibrium relationship of the reactions of formulas (6) to (6) is such that the synthesis reaction becomes significantly disadvantageous as the reaction temperature increases and the reaction pressure decreases. In order to improve the equilibrium relationship, the synthesis reaction is performed under high pressure. However, heat utilization is low from the viewpoint of equipment cost and operation cost, and it is desired to improve the reaction temperature and pressure characteristics. (C) When the methanol and methyl formate decomposition reactions of formulas (1) to (3) are performed in the gas phase, the reaction is performed at a pressure lower than the vapor pressure of methanol and methyl formate at the reaction temperature of formulas (1) to (3). There is a need. In addition, in order to efficiently perform the methanol and methyl formate decomposition reactions of the formulas (1) to (3) and the methanol and methyl formate synthesis reactions of the formulas (4) to (6) in consideration of the chemical equilibrium relationship, ~ (3)
The reaction pressure in the formula must be lower than the reaction pressure in formulas (4) to (6), and a compressor is required between the heat recovery side and the heat utilization side, and new mechanical energy must be input. And the heat utilization becomes low. (D) When performing the methanol / methyl formate decomposition reactions of the formulas (1) to (3) in the liquid phase, the methanol and methyl formate vapor pressures at the reaction temperatures of the formulas (1) to (3) are used to maintain the liquid phase. It is necessary to carry out the reaction at a high pressure. Therefore, together with carbon monoxide and hydrogen generated by the reactions of the formulas (1) to (3), methanol at the reaction temperature of the formulas (1) to (3), unreacted methanol corresponding to the vapor pressure of methyl formate, and methyl formate The heat corresponding to the latent heat of evaporation of the unreacted methanol and methyl formate discharged from the cracking reactor must be supplied to the heat other than the cracking reaction heat. Effective utilization of heat corresponding to the latent heat of vaporization of methanol and methyl formate is desired.

SUMMARY OF THE INVENTION An object of the present invention is to effectively utilize heat recovery in a thermal energy and chemical energy conversion system using a methanol / methyl formate decomposition reaction and a methanol / methyl formate synthesis reaction, and to reduce heat from the viewpoint of equipment cost and operation cost. The goal is to provide a highly available method.

[0007]

Means for Solving the Problems The present inventors have conducted intensive studies on a thermal energy and chemical energy conversion system having the above-mentioned problems, and found that the methanol-methyl formate liquid phase decomposition reaction of the formulas (1) to (3) was carried out. (Endothermic reaction) and the liquid phase synthesis reaction of methanol and methyl formate of formulas (4) to (6) (exothermic reaction) are combined, and the methanol and / or methyl formate decomposition reaction pressure is set to a pressure higher than the methanol and methyl formate synthesis reaction pressure. The present inventors have found that heat recovery, heat utilization, and power generation can be performed extremely advantageously by driving the expansion turbine to convert the energy into electric energy using the pressure difference between the two, and have reached the present invention.

That is, the present invention relates to methanol represented by the formulas (1) to (3):
Methyl formate liquid phase decomposition reaction (endothermic reaction) is combined to perform heat recovery, and power is generated by an expansion turbine using the decomposition product gas. Then, methanol and methyl formate liquid phase synthesis reactions of formulas (4) to (6) (heat generation) The method is a method of heat recovery, heat utilization, and power generation using chemical energy, which is characterized by performing heat utilization in combination with the reaction. CH ₃ OH → 2H ₂ + CO (1) 2CH ₃ OH → 2H ₂ + HCOOCH ₃ (2) HCOOCH ₃ → CH ₃ OH + CO (3) 2H ₂ + CO → CH ₃ OH (4) 2H ₂ + HCOOCH ₃ → 2CH ₃ OH (5) CH ₃ OH + CO → HCOOCH ₃ (6)

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, methanol-methyl formate liquid phase decomposition reaction (endothermic reaction) of the formulas (1) to (3) and (4)
The methanol-methyl formate liquid phase synthesis reaction (exothermic reaction) of formulas (6) to (6) is performed. Both reactions are performed in the presence of a catalyst. The methanol and / or methyl formate decomposition reaction pressure is set to a pressure higher than the methanol and methyl formate synthesis reaction pressure, and the expansion turbine (first expansion turbine) is driven by using the pressure difference between the two to convert the pressure into electric energy. In the present invention, adding formulas (2) and (3) yields formula (1), and formulas (1) to (3)
The equation is an endothermic reaction and is used for heat recovery. The heat recovery is performed by endothermic heat of the decomposition reaction of all or a part of the equations (1) to (3) in accordance with the temperature level and the quantitative distribution of the heat energy to be recovered. Thus, in heat recovery, the supplied methanol and / or methyl formate is transported to the heat utilization side in the form of chemical energy to carbon monoxide and / or hydrogen. The thus recovered thermal energy is transported in gaseous form in the form of carbon monoxide and / or hydrogen and is used for heat utilization. The heat utilization is obtained by adding the formulas (5) and (6) to obtain the formula (4), and according to the temperature level of the heat energy to be supplied and the quantitative distribution thereof, the formulas (4) to (6) are used. It is carried out by the exotherm of all or part of the synthesis reaction. The received carbon monoxide and / or hydrogen finally becomes methanol and / or methyl formate, which can be handled in the liquid phase, and releases a part of the chemical energy of carbon monoxide and / or hydrogen as heat of reaction to utilize heat. Is done. Methanol and / or methyl formate synthesized on the heat utilization side is recycled to the heat recovery side for reuse. Also, since both media are liquids,
It can be stored on the heat recovery side or heat utilization side.

In the methanol liquid phase decomposition reaction of the formula (1), the reaction temperature, the reaction pressure and the liquid hourly space velocity can be selected in a wide range depending on the type and amount of the catalyst and the target reaction rate. From 100 ° C. to 235 ° C. near the critical temperature of methanol, and practically preferably in the range of 150 to 230 ° C. If the reaction temperature is too low, a practical reaction rate cannot be obtained, and if the reaction temperature is too high, simultaneous side reactions and deactivation of the catalyst are likely to occur. The methanol vapor pressure at a reaction temperature of 100 to 235 ° C. is 0.35 to 7.49 MPa, and the reaction pressure is preferably higher than this, in the range of 1.39 to 7.49 MPa.
The liquid hourly space velocity is generally in the range of 0.1 to 10 (m ³ -methanol / hr / m ³ -catalyst), particularly 0.2 to 3 (m ³ -methanol / hr / m ³ -catalyst).

The methanol liquid phase decomposition reaction of the formula (2) is a formation reaction of methyl formate by a dehydrogenation reaction. The reaction temperature, reaction pressure and liquid hourly space velocity can be selected in a wide range depending on the amount of catalyst and the target reaction rate, but the general reaction temperature is 100 ° C to 210 ° C near the critical temperature of methyl formate, and is practical. Is preferably in the range of 150 to 205 ° C. If the reaction temperature is too low, a practical reaction rate cannot be obtained, and if the reaction temperature is too high, simultaneous side reactions and deactivation of the catalyst are likely to occur. The vapor pressure of methyl formate at a reaction temperature of 100 to 210 ° C is
0.77 to 5.54 MPa and the reaction pressure is higher than 2.1
The range of 8 to 5.54 MPa is preferred. Liquid space velocity is 0.1-10 (m
³ - methanol / hr / m ³ - catalytic) range, in particular 0.2 to 3 (m
³ -methanol / hr / m ³ -catalyst) is common.

In the liquid phase decomposition reaction of methyl formate of the formula (3), the reaction temperature, the reaction pressure and the liquid hourly space velocity can be selected in a wide range depending on the type and amount of the catalyst and the target reaction rate. The temperature is from 0 ° C. to 210 ° C. near the critical temperature of methyl formate, and practically preferably from 20 to 200 ° C. If the reaction temperature is too low, a practical reaction rate cannot be obtained, and if the reaction temperature is too high, simultaneous side reactions and deactivation of the catalyst are likely to occur. The vapor pressure of methyl formate at a reaction temperature of 0 to 210 ° C. is 0.03 to 5.54 MPa, and the reaction pressure is preferably in a higher pressure range of 1.03 to 5.54 MPa. The liquid hourly space velocity is 0.1 to 10 (m ³ -methyl formate / hr / m ³ -catalyst)
, Especially 0.2 to 3 (m ³ -methyl formate / hr / m ³ -catalyst)
Is common.

As a general reaction method of the formulas (1) to (3),
Any generally known method such as a suspension bed or a fixed bed, a batch system, a semi-batch system, and a flow system can be used.
Further, the methanol liquid phase decomposition reaction of the formula (1) is carried out in the liquid phase to remove the generated carbon monoxide gas and hydrogen gas out of the system, thereby promoting the equilibrium reaction. (1) 〜
The methanol and methyl formate used as a raw material in the reaction of the formula (3) are mixed with a methanol or methyl formate with a desiccant before use in order to avoid by-products such as carbon dioxide gas and to reduce the burden on the catalyst. Is preferably reduced.

In the liquid phase synthesis reaction of methanol from the mixed gas of hydrogen and carbon monoxide of the formula (4), the reaction temperature, reaction pressure and liquid space velocity depend on the type and amount of the catalyst, the type of the solvent used and the target. The reaction temperature can be selected from a wide range depending on the reaction rate, but the general reaction temperature is 80 to 200 ° C, and the range of 100 to 150 ° C is practically preferable. If the reaction temperature is too low, a practical reaction rate cannot be obtained, and if the reaction temperature is too high, simultaneous side reactions and deactivation of the catalyst are likely to occur. The solvent used may be altered depending on the conditions. The reaction pressure is preferably a pressure higher than the boiling point of the solvent used at a reaction temperature of 80 to 200 ° C., and it is necessary to be lower than the decomposition reaction pressure of the formulas (1) to (3). Is preferred. The gas hourly space velocity is in the range of 100 to 10,000 (m ^3- [carbon monoxide + hydrogen] / hr / m ³ -catalyst), especially 300 to 5
000 (m ^3- [carbon monoxide + hydrogen] / hr / m ³ -catalyst) is common.

In the methanol liquid phase synthesis reaction by hydrogenation of methyl formate of the formula (5), the reaction temperature, reaction pressure and liquid hourly space velocity can be selected in a wide range depending on the amount of catalyst and the target reaction rate. The typical reaction temperature is 100
C. to 210.degree. C., and practically preferably in the range of 120 to 200.degree. If the reaction temperature is too low, a practical reaction rate cannot be obtained, and if the reaction temperature is too high, simultaneous side reactions and deactivation of the catalyst are likely to occur. Reaction pressure is reaction temperature 100-2
The reaction pressure is preferably higher than the vapor pressure of methyl formate used at 00 ° C., and it is necessary to be lower than the decomposition reaction pressure of the formulas (1) to (3), so the pressure is in the range of 1.06 to 4.84 MPa. Is preferred. The ratio of hydrogen to methyl formate is preferably larger than the theoretical value in consideration of the reaction of methyl formate, and the molar ratio is 1 to 100 (hydrogen / methyl formate).
A range of 2 to 50 (hydrogen / methyl formate) is preferred. The liquid hourly space velocity is generally in the range of 0.1 to 10 (m ³ -methyl formate / hr / m ³ -catalyst), particularly 0.2 to 3 (m ³ -methyl formate / hr / m ³ -catalyst).

In the liquid phase synthesis reaction of methyl formate by the carbonylation reaction of methanol of the formula (6), the reaction temperature, reaction pressure and liquid hourly space velocity can be selected in a wide range depending on the type and amount of catalyst and the target reaction rate. However, the general reaction temperature is 0 ° C to 235 ° C, and practically 20 to 200 ° C.
C. is preferred. If the reaction temperature is too low, a practical reaction rate cannot be obtained, and if the reaction temperature is too high, simultaneous side reactions and deactivation of the catalyst are likely to occur. Reaction temperature 20 ~
The reaction pressure is preferably higher than the vapor pressure of methanol used at 200 ° C., and it is necessary to be lower than the decomposition reaction pressure of the formulas (1) to (3), so the pressure is preferably in the range of 0.01 to 4.06 MPa. preferable. The ratio of carbon monoxide to methanol is preferably larger than the theoretical value in consideration of the reaction of methanol, and the molar ratio is preferably 1 to 100 (carbon monoxide / methanol).
Practically, the range of 1.2 to 50 (carbon monoxide / methanol) is preferable. The liquid hourly space velocity is generally in the range of 0.1 to 10 (m ³ -methanol / hr / m ³ -catalyst), particularly 0.2 to 3 (m ³ -methanol / hr / m ³ -catalyst).

As a general reaction method of the formulas (4) to (6), any known method such as a suspension bed or a fixed bed, a batch system, a semi-batch system, and a flow system can be used. it can. As the catalyst, either a homogeneous catalyst or a heterogeneous catalyst can be used. The methanol and methyl formate used as the raw materials in the reactions of the formulas (4) to (6) are prepared by using a desiccant or the like prior to use in order to avoid by-products such as carbon dioxide gas and to reduce the burden on the catalyst. It is preferable to reduce the water content in methanol and methyl formate. In a reaction using a solvent, the same consideration must be given to the water content in the solvent as for the raw material.

The methanol and methyl formate decomposition reactions of the formulas (1) to (3) and the methanol and methyl formate synthesis reactions of the formulas (4) to (6) are reversible equilibrium reactions, and the selectivity is 100%. Although there is no problem in terms of balance, since it is a chemical reaction, there are some side reactions, and methane, carbon dioxide and the like may accumulate. Since these by-products are mainly concentrated in the outlet gas of the methanol and methyl formate synthesis reactors of formulas (4) to (6), they are recovered as thermal energy by separating and burning them. . The substance supplied at this time is methanol,
Methanol is an inexpensive substance close to the fuel price, so that the economic losses associated with processing by-products are kept low.

In the present invention, in order to enhance the heat utilization efficiency, an expansion turbine (second expansion turbine) of ammonia water mixed steam using exhaust gas of an expansion turbine (first expansion turbine) using decomposition product gas is installed, and power generation is performed. Is preferably performed. That is, a heat exchanger for evaporating ammonia water, a gas-liquid separator, a second expansion turbine, a generator, a heat exchanger for condensing ammonia water, an ammonia water liquid pump, and a heat exchanger for preheating are attached to the first expansion turbine outlet, Electrical energy is converted by evaporating and condensing the ammonia water using excess recovered thermal energy. The ammonia concentration of the ammonia water and the pressure of the ammonia water evaporation heat exchanger can be selected in a wide range depending on the temperature level of the heat supplied to the ammonia water evaporation heat exchanger. It is 100 wt%, and practically, the range of 75 to 100 wt% is preferable. General pressure of heat exchanger for ammonia water evaporation is 1 ~ 8MPa, practically 2 ~ 5M
Pa is preferred. Each expansion turbine has a 90/10 steam / liquid ratio at the expansion turbine outlet to maintain its efficiency.
It is necessary to set the outlet pressure so as to be 〜100 / 0. In practice, the outlet pressure is set such that the ratio of steam and liquid at the outlet of the expansion turbine is 95/5 to 100/0.

Further, one or more heat exchangers are provided for the methanol-methyl formate liquid phase decomposition reactors of the formulas (1) to (3) and the methanol-methyl formate liquid phase synthesis reactors of the formulas (4) to (6). By attaching, excess heat energy recovered can be efficiently exchanged into the system. The number of heat exchangers is determined by the conditions of the methanol / methyl formate liquid phase decomposition reaction and the methanol / methyl formate liquid phase synthesis reaction and the pressure at the outlet of the expansion turbine, but from 1 to 15 is practically preferable.

The specific flow of the present invention will be described in the following examples. According to the present invention, the decomposition reaction of methanol and methyl formate is made into a liquid phase reaction by increasing the vapor pressure of methanol and methyl formate at the reaction temperature. And the methanol and / or methyl formate decomposition reaction pressure is higher than the methanol and / or methyl formate synthesis reaction pressure, and a heat exchanger, a gas-liquid separator, a first expansion turbine, Attach a generator and a methanol liquid pump to collect electric energy, and at the outlet of the first expansion turbine, heat exchanger for evaporating ammonia water, gas-liquid separator, second expansion turbine, generator, heat exchange for condensing ammonia water The amount of power generation can be increased by installing a vessel and an ammonia liquid pump. In addition, steam or hot water of about 144 ° C. is generated from the reaction heat of the methanol synthesis reaction. In the system of the present invention, methanol, decomposition gas from a methyl formate decomposition reactor and methanol, methanol and methyl formate from a methyl formate synthesis reactor can be transported over a long distance at around room temperature. The heat recovery of waste heat and the use of heat for steam and hot water heating in urban areas can be advantageously performed even when the distance is considerable.

[0022]

Next, the present invention will be described in more detail by way of examples. However, the present invention is not limited to these examples.

REFERENCE EXAMPLE 1 (Methanol liquid phase decomposition reaction of formula (1)) 24 g of methanol was placed in a shaking autoclave having an inner volume of 100 ml.
(3.0 g of sodium methylate) and 3.0 g of a reduced copper-chromium catalyst (G-13A manufactured by Nissan Gadler Co., Ltd.) at a reaction temperature of 200 ° C. for 3.0 hours.
7.10MPa was reached. Thereafter, the autoclave was cooled in water, the valve in the gas phase was opened, and the internal gas was gradually extracted, weighed, and analyzed by gas chromatography. The generated gas amount was 1.07 NL, and the carbon monoxide concentration was 17.9 vol%.

Reference Example 2 (Methanol liquid phase decomposition reaction of formula (1)) Raney copper-chromium catalyst (manufactured by Nikko Rica Co., Ltd.) developed with 200 ml of methanol and an alkaline aqueous solution in a 500-ml tank-type reactor equipped with a stirrer ) 42.9 g was charged and the reactor was assembled. After the system was filled with nitrogen gas, the operation of evacuating was repeated several times to replace the gas in the system. Stirring speed 10
The heating temperature of the reactor was set to 00 rpm, and the reaction temperature was set to 192 ° C. As the temperature increased, the pressure in the system also increased. When the pressure reached a predetermined withdrawal pressure of 4.6 MPa, the outlet-side pressure regulating valve was adjusted to start extracting product gas. The gas is extracted through a cooler placed above the reactor, and condensed components such as methanol entrained in the gas are removed from the cooler (0
℃), condensed and returned to the reactor. The gas amount was measured with a gas meter, sampled with time, and analyzed by gas chromatography. In addition, the raw material methanol was 0.5 wt% of sodium methylate, one of the catalyst components.
The solution was used and supplied at a predetermined flow rate by a plunger pump. The reaction product liquid was withdrawn through a control valve (electromagnetic valve) so that the liquid level in the reactor was constant (remaining liquid volume: 300 ml). As a result, a product gas having a carbon monoxide concentration of 33.5 vol% was obtained at a rate of 15.6 NL / h,
The methanol conversion with respect to the methanol supply was 62.2%.

Reference Example 3 (Liquid phase decomposition reaction of methanol of formula (1)) A copper-chromium-manganese-barium catalyst reduced in a tank reactor having an inner volume of 500 ml (G-99-B manufactured by Nissan Gardler Co., Ltd.) -
0) 120 g and 30 ml of methanol containing 5 mol% of methyl formate were charged, and heating was started after gas replacement in the system. The liquid level in the reactor was detected by an electrode inserted into the reactor, and methanol containing 5 mol% of methyl formate was continuously supplied by a plunger pump so that the liquid level was constant. Condensed components such as methanol entrained in the produced gas were cooled and condensed in the cooler (0 ° C.) and returned into the reactor. The amount of generated gas was measured by a gas meter. Catalyst layer temperature 197 ° C, reaction pressure 5.1MP
Under the conditions of a and the raw material supply rate of 12.2 g / h, a gas having 65.1% of hydrogen and 31.4% of carbon monoxide was generated at a rate of 25.2 NL / h.

Reference Example 4 (Methanol liquid phase decomposition reaction of formula (2)) Raney copper catalyst (Nikko Rika Co., Ltd.) 44.2 g and 30 m
l of methanol was charged, and heating was started after gas replacement in the system. The liquid level in the reactor was detected by an electrode inserted into the reactor, and methanol was supplied by a plunger pump so that the liquid level was constant. The condensed components such as raw material methanol and the target product, methyl formate, entrained in the produced gas were cooled and condensed in the cooler (0 ° C.) and taken out of the reaction system. The amount of generated gas was measured by a gas meter. As a result, under the conditions of a catalyst layer temperature of 177 ° C., a reaction pressure of 3.1 MPa, and a methanol supply amount of 107.9 g / h, the methanol conversion was 25.
The yield was 4%, and the methyl formate yield was 10.3%.

Reference Example 5 (Methyl formate liquid phase decomposition reaction of formula (3)) A reaction tube having an inner diameter of 35 mm and a length of 200 mm was filled with 100 ml of ion exchange resin (SA-10A manufactured by Mitsubishi Chemical Corporation). The reaction conditions were a catalyst layer temperature of 70 ° C. and a reaction pressure of 0.6 MPa, and methyl formate was continuously supplied from the lower part of the reaction tube at a liquid hourly space velocity of 0.5 / h with respect to the catalyst capacity. As a result, a gas chromatographic analysis yielded a cracked gas of substantially only carbon monoxide containing no components other than methanol and methyl formate corresponding to the accompanying vapor pressure, and the carbon monoxide yield based on the supplied methyl formate was 55.1%. %Met.

Reference Example 6 (Methyl formate liquid phase decomposition reaction of formula (3)) In a tank reactor having an inner volume of 500 ml, 2.5 wt.
200 ml of an equimolar mixed solution of methyl formate and methanol in which cesium carbonate was dissolved in an amount to give a% concentration was charged, and the system was heated after gas replacement. The reaction conditions are as follows.
The experiment was carried out at a temperature of ℃ and a reaction pressure of 9.1 MPa by a flow system. Condensed components such as methyl formate and methanol entrained in the gas were cooled and condensed in the cooler (0 ° C.) to separate the gas, and then returned to the reactor. The amount of generated gas was measured by a gas meter.
The raw material solution is supplied in the form of a mixed solution of methyl formate, methanol and cesium carbonate catalyst using a plunger pump, and the liquid level in the reactor is detected by the electrode inserted in the reactor, and the liquid level is kept constant (retained). A part of the reaction solution was drawn out of the reaction system so as to have a liquid volume of 300 ml). The liquid hourly space velocity based on the reaction liquid was 0.14 / h. As a result, the methyl formate reaction rate was 80.3
% And the carbon monoxide yield was 78.1%.

Reference Example 7 (Methyl formate liquid phase decomposition reaction of formula (3)) A reaction tube having an inner diameter of 13 mm and a length of 300 mm was filled with 15 ml of an ion exchange resin (SA-10A manufactured by Mitsubishi Chemical Corporation). The raw material was continuously supplied from the lower part of the reaction tube using a mixture of methanol and methyl formate in a molar ratio of 1: 0.9. The experiment was conducted under the conditions that the liquid hourly space velocity with respect to the catalyst volume was 0.25 / h, the catalyst layer temperature was 70 ° C, and the reaction pressure was 0.6 MPa. A product gas substantially containing only carbon monoxide was obtained, and the conversion to the supplied methyl formate was 87.8%.

REFERENCE EXAMPLE 8 (Methanol liquid phase synthesis reaction of formula (4)) Raney copper manufactured by Nikko Rica Co., Ltd. developed with 100 ml of metaxylene and an aqueous alkali solution as a solvent in a 500-ml tank-type stainless steel reactor equipped with a stirrer. A reactor was assembled by charging 40.4 g of the catalyst and 15 g of a 28 wt% sodium methoxide methanol solution. After the system was filled with nitrogen gas, the operation of evacuating was repeated several times to replace the gas in the system. Subsequently, a mixed gas having a hydrogen / carbon monoxide ratio of 2 was added to 4.00 MPa.
Filled. The stirring speed was set at 1000 rpm, and the temperature of the reactor was set at 110 ° C.
Heated. The reaction was maintained at this temperature for 1 hour. Thereafter, the reactor was cooled. The gas phase was gradually extracted, and the gas amount was measured and analyzed. As a result, the conversion of carbon monoxide was 78.6%, and the selectivity for methanol was 88.9%.

Reference Example 9 (Methyl formate hydrogenation reaction of formula (5)) A granular Raney copper catalyst (Nikko Rica Co., Ltd.) developed in a reaction tube having an inner diameter of 15 mm and a length of 200 mm with a 5 W% aqueous sodium hydroxide solution
10 ml was filled. The reaction conditions were a catalyst layer temperature of 160 ° C., a reaction pressure of 3.3 MPa, a hydrogen / methyl formate molar ratio of 2.2, and a methyl formate supply amount of a liquid space velocity of 1.87 / h with respect to the catalyst capacity. Methyl formate and hydrogen were continuously supplied from the upper part of the reaction tube. As a result, the methyl formate reaction rate was 80.7%, and the methanol selectivity was 94.0%.

Reference Example 10 (Methanol carbonylation reaction of formula (6)) In a tank-type stainless steel reactor having an internal volume of 100 ml and equipped with a stirrer, 15 ml of ion-exchange resin (manufactured by Bayer KK) and 50 g of methanol were used.
Was charged. The reaction conditions were as follows: catalyst layer temperature 60 ° C, reaction pressure 5.1M
The reaction was performed for 5 hours as Pa. Note that carbon monoxide was supplied so that the reaction pressure became constant. As a result, the methanol conversion was 82.1%, and the methyl formate yield was 76.9%.

Example 1 Using the data of the above reference example, calculation of a heat recovery and heat utilization and power generation system according to the present invention was performed based on the flow of FIG. 1 (using a process simulator ASPEN PLUS of Aspen Technology, Inc.). . FIG. 1 is an example of a flowchart showing a heat recovery and heat utilization system of the present invention.

(System Concerning Methanol-Methyl Formate Decomposition Reaction) In FIG. 1, methanol and methyl formate, which are raw materials for the reactions of formulas (1) and (3), are supplied through a flow path 100 and a heat exchanger E10.
0, preheating is performed by heat exchange inside the system via the flow path 110, and the preheated liquid is supplied to the methyl formate liquid phase decomposition reactor R100. The methyl formate liquid phase decomposition reactor R100 is filled with the ion exchange resin used in Reference Example 7, and performs a methyl formate liquid phase decomposition reaction at a temperature of 70 ° C. and a pressure of 0.61 MPa (a methyl formate reaction rate of 54.4%).
%). Methanol (including unreacted supply methanol), carbon monoxide, and unreacted methyl formate generated by the liquid phase decomposition reaction of methyl formate pass through channel 120, heat exchanger E100, and channel 125.
And enters the gas-liquid separator F130. Gas phase discharged from the gas-liquid separator F130 (excluding methanol at 51.3 ° C, methanol / methyl formate corresponding to the vapor pressure of methyl formate, and carbon monoxide dissolved in liquid-phase methanol / methyl formate) Carbon monoxide) is pressurized through a CO gas compressor C100 from a flow path 130, and is supplied to a gas-liquid separator F10 through a flow path 140.
Supplied to 0. Note that cooling water from the outside of the system is supplied to the gas-liquid separator F100 from the flow path 1040, discharged out of the system from the flow path 1050, and used for cooling heat in the gas-liquid separator F100. Gas phase discharged from gas-liquid separator F100 (gas-liquid separator F100 temperature 5
Methanol at 0.0 ° C., methanol / methyl formate corresponding to the vapor pressure of methyl formate, and carbon monoxide (except for carbon monoxide dissolved in liquid-phase methanol / methyl formate) generated in channel 15
0 and further pressurized through a CO gas compressor C110,
After 60, it is supplied to the gas-liquid separator F110. Gas-liquid separator F100
The liquid phase (methanol / methyl formate, carbon monoxide dissolved in methanol / methyl formate) discharged from
Preheating is performed by heat exchange inside the system via the flow path 190, the heat exchanger E110, and the flow path 200, and the methanol / methyl formate liquid pump P1
00 is supplied. The liquid phase (methanol / methyl formate, carbon monoxide dissolved in methanol / methyl formate) discharged from the gas-liquid separator F130 joins the flow channel 170 via the flow channel 180. Methanol and methyl formate, which are the raw materials for the reactions of formulas (1) and (3), are methanol / methyl formate liquid pumps.
From the outlet flow path 210 of P100, preheating is performed by heat exchange inside the system via the heat exchanger E120, the flow path 220, the heat exchanger E130, and the flow path 230, and supplied to the methanol / methyl formate liquid phase decomposition reactor R110. You. Exhaust gas from the outside of the system is supplied to the methanol / methyl formate liquid phase decomposition reactor R110 from the channel 1000,
Heat is recovered from exhaust gas discharged from the flow path 1010 and heated from outside the system. The methanol / methyl formate liquid-phase decomposition reactor R110 was filled with the copper-chromium-manganese-barium catalyst used in Reference Example 3, and was heated at a temperature of 197 ° C and a pressure of 197 ° C.
The liquid phase decomposition reaction of methanol and methyl formate is performed at 5.56 MPa (methanol conversion 10.8%, methyl formate conversion
97.4%). Carbon monoxide, hydrogen, unreacted methanol, and methyl formate generated by the liquid phase decomposition reaction of methanol and methyl formate enter the gas-liquid separator F120 via the flow path 240, the heat exchanger E130, and the flow path 260. The liquid phase (unreacted methanol / methyl formate, carbon monoxide / hydrogen dissolved in unreacted methanol / methyl formate) discharged from gas-liquid separator F120
270, supplied to a methanol / methyl formate liquid phase decomposition reactor R110 via a methanol / methyl formate liquid pump P110 and a flow path 280, and supplied to a gas phase (gas / liquid separator F120, corresponding to the vapor pressure of methanol and methyl formate at a temperature of 194.3 ° C). The unreacted methanol / methyl formate and the carbon monoxide / hydrogen produced excluding the carbon monoxide / hydrogen dissolved in the liquid phase unreacted methanol / methyl formate) are supplied to the first expansion turbine EX100 from the flow path 290. The gas decompressed by the first expansion turbine EX100 flows through the flow path 30
0, heat exchanger E120, flow path 310, heat exchanger E140, flow path 320, the heat of reaction and the latent heat of vaporization of unreacted methanol / methyl formate by internal heat exchange in the liquid phase cracking reactor R100 of methyl formate Is supplied to the gas-liquid separator F140 via the flow path 325. Gas phase discharged from gas-liquid separator F140 (methanol at gas-liquid separator F140 temperature of 70.0 ° C, methanol / methyl formate corresponding to vapor pressure of methyl formate, carbon monoxide / hydrogen dissolved in liquid-phase methanol / methyl formate Excluding generated carbon monoxide / hydrogen) flow path 340, heat exchanger E110,
The gas is supplied to the gas-liquid separator F110 via the flow path 350. Note that cooling water from outside the system is supplied to the gas-liquid separator F110 from the flow path 1020, discharged out of the system from the flow path 1030, and used for cooling heat in the gas-liquid separator F110. The liquid phase (methanol / methyl formate, carbon monoxide / hydrogen dissolved in methanol / methyl formate) discharged from the gas-liquid separator F110 is supplied to the methanol / methyl formate liquid pump P100 via the flow path 370 and the flow path 380. You.
The liquid phase (methanol / methyl formate, carbon monoxide / hydrogen dissolved in methanol / methyl formate) discharged from the gas-liquid separator F140 is joined to the flow path 370 via the flow path 330. Gas phase discharged from gas-liquid separator F110 (gas-liquid separator
F110 methanol at 25 ° C, unreacted methanol / methyl formate corresponding to the vapor pressure of methyl formate, and carbon monoxide / hydrogen produced excluding carbon monoxide / hydrogen dissolved in liquid phase unreacted methanol / methyl formate) Transported over long distances by 360 (transport distance 10 km, pressure loss 0.05 MPa). On the other hand, the liquid phase (methanol / methyl formate, carbon monoxide / hydrogen dissolved in methanol / methyl formate) discharged from the heat exchanger E520 is transported over a long distance by the flow path 100 (transport distance 10 k).
m, pressure loss 0.303MPa).

(System Related to Methanol Synthesis Reaction) Carbon monoxide and hydrogen, which are the raw materials for the reactions of formulas (5) and (6), pass through the flow path 360, the heat exchanger E500, the flow path 500, and the flow path 530. Preheating by internal heat exchange is performed, and the resultant is supplied to a methanol carbonylation liquid phase synthesis reactor R500. The methanol carbonylation liquid phase synthesis reactor R500 is filled with the ion exchange resin used in Reference Example 10, and performs a methanol carbonylation liquid phase synthesis reaction at a temperature of 60 ° C. and a pressure of 3.03 MPa (methanol conversion rate 16.3%). . Methyl formate (including unreacted supply methyl formate) and unreacted methanol, carbon monoxide, and unreacted supply hydrogen generated by the methanol carbonylation liquid phase synthesis reaction enter the gas-liquid separator F500 via the flow path 540. Gas phase discharged from gas-liquid separator F500 (Methanol at gas-liquid separator F500 temperature 60.0 ° C, methanol / methyl formate corresponding to vapor pressure of methyl formate, carbon monoxide / hydrogen dissolved in liquid-phase methanol / methyl formate Excludes carbon monoxide / hydrogen) from channel 550 through CO / hydrogen gas compressor C500, channel 560, channel
610, heat pre-heating by pressurization and internal heat exchange via heat exchanger E510 and flow path 620, and supplied to methyl formate hydrogenation liquid phase synthesis reactor R510, liquid phase (methanol / methyl formate, methanol / methyl formate) The carbon monoxide / hydrogen dissolved in water is pressurized through a flow path 590 branched from a flow path 570, a methanol / methyl formate liquid pump P500, and a flow path 600, and merges into a flow path 560. In addition, a part of the liquid phase in the flow path 570 is branched into the flow path 580, and merges with the flow path 690. The methyl formate hydrogenation liquid phase synthesis reactor R510 is packed with the granular Raney copper catalyst used in Reference Example 9, and performs a methyl formate hydrogenation liquid phase synthesis reaction at a temperature of 150 ° C. and a pressure of 3.03 MPa (methyl formate reaction). Rate 11.4
%). Methanol (including unreacted supply methanol) and unreacted methyl formate, unreacted supply carbon monoxide and unreacted hydrogen produced by the liquid phase synthesis reaction of methyl formate hydrogenation pass through channel 630, heat exchanger E510, channel 635, The gas-liquid separator F510 enters the heat exchanger E530. The gas phase discharged from the gas-liquid separator F510 (methanol at a temperature of 150.0 ° C. in the gas-liquid separator F510, methanol / methyl formate corresponding to the vapor pressure of methyl formate, and carbon monoxide / hydrogen dissolved in the liquid-phase methanol / methyl formate) (Excluding carbon monoxide / hydrogen) is pressurized from a flow path 650 through a CO / hydrogen gas compressor C510, a flow path 510, and a flow path 520, and the flow path 500
And the liquid phase (methanol / methyl formate, carbon monoxide / hydrogen dissolved in methanol / methyl formate)
The fluid is pressurized via a flow path 670 branched from zero, a methanol / methyl formate liquid pump P510, and a flow path 680, and merges with the flow path 510. In addition, a part of the liquid phase in the flow path 660 is a flow path 690, a flow path 700,
The heat is supplied to the heat exchanger E520 via the heat exchanger E500 and the flow path 710. The cooling water from the outside of the system flows from the flow path 1060 to the heat exchanger.
It is supplied to E520, discharged out of the system from the flow path 1070, and used for cooling heat in the heat exchanger E520. Here, hot water and water used for producing steam are supplied from the outside of the system from the channel 1200, heated in the methanol carbonylation liquid-phase synthesis reactor R500, and heated from the channel 1220 branched from the channel 1210. Is discharged out of the system and used for heat. In addition, a part of the hot water in the flow path 1210 is branched to a flow path 1230, preheating is performed by heat exchange inside the system in a heat exchanger E530, a flow path 1240, a methyl formate hydrogenation liquid phase synthesis reactor R510, a flow path After 1250, steam is discharged out of the system and used for heat.

(System related to evaporation and condensation of ammonia water)
The aqueous ammonia condensed in the heat exchanger E410 is supplied to the aqueous ammonia liquid pump P400 via the flow path 400. The flow path
Cooling water from outside the system is supplied from 1100 to the heat exchanger E410, discharged out of the system from the flow path 1110, and used for heat of condensation in the heat exchanger E410. Outlet flow path of ammonia water liquid pump P400
From 410, the condensed ammonia water is preheated by heat exchange inside the system in the heat exchanger E400, and most of the water is evaporated by heat exchange inside the system in the heat exchanger E140 via the flow path 420, and the flow path 43
After passing through 0, it is supplied to the gas-liquid separator F400. Gas-liquid separator F400
The liquid phase discharged from channel 440, heat exchanger E400, channel 450
, Is supplied to the heat exchanger E410, the gas phase is supplied to the second expansion turbine EX400 from the flow path 460, and the decompressed gas is supplied to the heat exchanger E410 via the flow path 470. The first
Power is generated from the generator M100 connected to the expansion turbine EX100 and the second expansion turbine EX400.

Tables 1 to 4 show the temperature, pressure and composition of each component in each channel. In the following table, the blank portion indicates that it is the same as the previous channel, and “liquid” in the column of each component composition indicates a liquid, “gas” indicates a gas, and “mixed” indicates a gas-liquid state.

[0038]

[Table 1]

[0039]

[Table 2]

[0040]

[Table 3]

[0041]

[Table 4]

The amounts of heat exchange of the heat exchanger, the gas-liquid separator and the reactor are as follows.

[Table 5]

The specifications of the liquid pump, the expansion turbine, and the gas compressor were as follows. Methanol / methyl formate liquid pump (Pump efficiency 90%) P100: Power consumption 63 KWH, P110: Power consumption 1 KWH P500: Power consumption 6 KWH, P510: Power consumption 6 KWH Ammonia water liquid pump (Pump efficiency 90%) P400: Power consumption 58 KWH Expansion turbine (80% adiabatic efficiency) EX100: Generated power 794KWH, EX400: Generated power 1061KWH Gas compressor (Adiabatic efficiency 85%) C100: Power consumption 53KWH, C110: Power consumption 54KWH C500: Power consumption 67KWH, C510 : Power consumption 55KWH

In the above system, the amount of heat recovered from the outside (using 200 ° C. exhaust gas) in the methanol-methyl formate liquid phase decomposition reaction by the reactions of the equations (1) and (3) is 60.
678 × 106 kJ / hr, externally used heat (water vapor at 144 ° C. and hot water at 55 ° C.) in the liquid phase synthesis reaction of methanol and methyl formate by the reactions of equations (5) and (6) is (6.555+
10.339 + 11.498) x 106 = 28.392 x 106 kJ / hr, and the amount of power generation (difference between generated power and consumed power) is [(794 + 1061)-(6
3 + 1 + 6 + 6 + 58 + 53 + 54 + 67 + 55)] = 1492 KWH, which is 14.051 x 106 kJ / hr when the power generation efficiency is 38.2%. From this, the heat transfer efficiency [(+) /] of this system is 70.0
%. Therefore, it can be seen that in this system, the use of steam at 144 ° C and the use of warm heat at 55 ° C and power generation can be performed with extremely high efficiency from a relatively low-temperature exhaust heat source at 200 ° C.

Example 2 In the same manner as in Example 1 except for the following conditions, calculation of heat recovery, heat utilization, and a power generation system according to the present invention was performed based on a reference example. Methanol and methyl formate liquid phase decomposition reaction pressure 6.77 MPa (R110: methanol conversion rate 20.4%, methyl formate reaction rate 98.6%), methanol carbonylation liquid phase synthesis reaction temperature 70 ° C, pressure 4.04 MPa (R500: methanol conversion rate 21.9% ) And methyl formate hydrogenation liquid phase synthesis reaction temperature 16
0 ° C, pressure 4.04MPa (R510: methyl formate reaction rate 14.8%)

Tables 6 to 9 show the temperature, pressure and composition of each component in each channel. In the following table, the blank portion indicates that it is the same as the previous channel, and “liquid” in the column of each component composition indicates a liquid, “gas” indicates a gas, and “mixed” indicates a gas-liquid state.

[0047]

[Table 6]

[0048]

[Table 7]

[0049]

[Table 8]

[0050]

[Table 9]

The heat exchange amounts of the heat exchanger, the gas-liquid separator and the reactor are as follows.

[Table 10]

The specifications of the liquid pump, the expansion turbine, and the gas compressor were as follows. Methanol / methyl formate liquid pump (Pump efficiency 90%) P100: Power consumption 46 KWH, P110: Power consumption 1 KWH P500: Power consumption 5 KWH, P510: Power consumption 5 KWH Ammonia water liquid pump (Pump efficiency 90%) P400: Power consumption 35 KWH Expansion turbine (80% adiabatic efficiency) EX100: Generated power 493KWH, EX400: Generated power 503KWH Gas compressor (Adiabatic efficiency 85%) C100: Power consumption 64KWH, C110: Power consumption 62KWH C500: Power consumption 39KWH, C510 : Power consumption 29KWH

In the above system, the amount of heat recovered from the outside (using the exhaust gas at 200 ° C.) in the liquid phase decomposition reaction of methanol and methyl formate by the reactions of the formulas (1) and (3) is 44.
104 x 106 kJ / hr, the heat used externally in the liquid phase synthesis reaction of methanol and methyl formate by the reactions of equations (5) and (6) (using steam at 144 ° C and hot water at 65 ° C) is (5.222+
9.627 + 13.354) x 106 = 28.203 x 106 kJ / hr, and the amount of power generation (difference between generated power and consumed power) is [(493 + 503)-(4
6 + 1 + 5 + 5 + 35 + 64 + 62 + 39 + 29)] = 710 KWH, which is 6.686 x 106 kJ / hr when the power generation efficiency is 38.2%. From this, the heat transfer efficiency [(+) /] of this system was 79.1.
%. Therefore, it can be understood that the present system can use a relatively low-temperature exhaust heat source at 200 ° C. to use steam at 144 ° C., use heat at 65 ° C., and generate power with extremely high efficiency.

[0054]

As is clear from the above embodiments, in the method of heat recovery, heat utilization and power generation according to the present invention, a heat recovery source of about 150 to 250 ° C., which was conventionally highly efficient and difficult to utilize heat, was used.
Generates steam at about 144 ° C, generates hot water at 55 to 65 ° C, and generates electricity with extremely high efficiency, which has never been obtained before.Various heat sources and cooling and heating systems in factories and urban heat demand areas Can be used effectively. In addition, generation of electricity eliminates restrictions due to the distance between the heat recovery side and the heat utilization side. In the method of the present invention, the reaction is carried out under relatively low temperature and mild conditions, so that the equipment cost can be reduced, and if liquid phase reaction is used, heat recovery, heat utilization and power generation can be performed efficiently, so that energy saving measures can be taken. This is an extremely excellent method.

[Brief description of the drawings]

FIG. 1 is an example of a flowchart showing a heat recovery and heat utilization system of the present invention.

[Explanation of symbols]

C100, C110 CO gas compressor C500, C510 CO / H2 gas compressor E100, E110, E120, E130, E140,
E400, E410, E500, E510, E520,
E530 Heat exchanger EX100 First expansion turbine EX400 Second expansion turbine F100, F110, F120, F130, F140,
F400, F500, F510 Gas-liquid separator M100 Generator P100, P110, P500, P510 Methanol / methyl formate liquid pump P400 Ammonia water liquid pump R100 Methyl formate liquid phase decomposition reactor R110 Methanol / methyl formate liquid phase decomposition reactor R500 formic acid Methyl hydrogenation liquid phase synthesis reactor R510 Methanol carbonylation liquid phase synthesis reactor

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuyuki Matsumura 9-2 Kizugawadai, Kizu-cho, Kizu-cho, Soraku-gun, Kyoto Prefecture Within the National Research Institute for Earth-Environmental Technology (72) Inventor Shiro Kajiyama 2-5 Marunouchi, Chiyoda-ku, Tokyo No. 2 Sanrishi Gas Chemical Co., Ltd.

Claims (4)

[Claims] 1. Heat recovery is performed by combining a liquid phase decomposition reaction (endothermic reaction) of methanol and methyl formate of the formulas (1) to (3), and after generating power by an expansion turbine using a decomposition product gas,
Heat recovery, heat utilization and power generation using chemical energy of methanol / methyl formate, characterized by performing heat utilization by combining the liquid phase synthesis reaction (exothermic reaction) of methanol and methyl formate of formulas (4) to (6) Method. CH ₃ OH → 2H ₂ + CO (1) 2CH ₃ OH → 2H ₂ + HCOOCH ₃ (2) HCOOCH ₃ → CH ₃ OH + CO (3) 2H ₂ + CO → CH ₃ OH (4) 2H ₂ + HCOOCH ₃ → 2CH ₃ OH (5) CH ₃ OH + CO → HCOOCH ₃ (6) 2. The methanol and / or methyl formate liquid phase decomposition reactions of formulas (1) to (3) are carried out at a higher pressure than the methanol and methyl formate liquid phase synthesis reactions of formulas (4) to (6). The method for heat recovery, heat utilization and power generation using chemical energy according to claim 1, wherein power generation is performed by a pressure difference. 3. The heat recovery and heat using chemical energy according to claim 1 or 2, wherein an expansion turbine of ammonia water mixed steam using exhaust gas of the expansion turbine by the decomposition product gas is installed, and power is further generated. How to use and generate electricity. 4. Methanol of formulas (1) to (3), methanol in a liquid formic acid decomposition reactor and / or methanol of formulas (4) to (6),
The method for heat recovery, heat utilization and power generation using chemical energy according to any one of claims 1 to 3, wherein heat recovery and / or heat utilization is performed by a heat exchanger mounted in the methyl formate liquid phase synthesis reactor.