KR20100087388A - Method of regulating temperature in reaction vessel, reactor, and process for producing dimethyl ether - Google Patents

Abstract

An object of the present invention is to improve the controllability of temperature and conversion rate in a reactor in synthesizing dimethyl ether from methanol, for example, by an equilibrium reaction involving an exothermic reaction. In the present invention, a plurality of catalyst layers are provided in a reactor, and a quench zone for cooling a mixture containing methanol and dimethyl ether is provided between these catalyst layers, and at least of water generated together with dimethyl ether and dimethyl ether in the quench zone. The liquid containing either is supplied as a quench fluid.

Description

Temperature control method inside the reactor, reactor and production method of dimethyl ether {METHOD OF REGULATING TEMPERATURE IN REACTION VESSEL, REACTOR, AND PROCESS FOR PRODUCING DIMETHYL ETHER}

The present invention relates to a temperature control method inside a reactor, a reaction apparatus, and a manufacturing method of dimethyl ether, which are supplied when a raw material is supplied to an adiabatic reactor and the target product is produced by an equilibrium reaction involving exothermic heat.

In a manufacturing plant, a catalyst layer may be provided in a reactor, the raw material may be made to flow through it, and it may react, and the product which is the reaction product may be obtained. One of the important operating conditions for properly proceeding the reaction in the reactor is temperature management in the reactor. Generally, in order to adjust the temperature in a reactor so that it may become a temperature suitable for reaction, after adjusting a raw material to preset temperature, it is made to supply to a reactor.

In the case where the above reaction is an exothermic reaction, the temperature of the raw material increases as the raw material flows into the reactor toward the downstream side, that is, as the reaction proceeds. When the temperature of the raw material is higher than the temperature range suitable for the main reaction, undesirable by-products (impurities) are produced, and the catalyst is degraded by the loss of the raw material or by promoting the coking, while the temperature of the raw material is in the above temperature range. Since the yield falls below, the various methods of keeping the temperature in a catalyst layer within the target temperature range are proposed. As a representative example for maintaining the temperature in such a reactor, the following method is known.

FIG. 14 is a multi-tubular reactor 100, which feeds raw materials into a plurality of pipes 101 arranged side by side in the multi-tubular reactor 100, reacts in the tube 101, and the tube 101 is external. It is configured to cool by the refrigerant from the. In this multi-tubular reactor 100, the raw material can be cooled reliably and quickly, but since a large amount of refrigerant is required and the structure of the reactor 100 is complicated, the cost of the apparatus becomes high, which is unsuitable for further enlargement. .

FIG. 15 shows an apparatus in which a plurality of reactors 102 are connected and a heat exchanger (intermediate heat exchanger) 103 is provided between the reactors 102 and 102. In this apparatus, the raw material supplied into the reactor 102 in the first stage is exothermic by the reaction in the reactor 102 in the first stage, and is then cooled by the heat exchanger 103, followed by the reactor 102 in the second stage. Is supplied to the reactor, and the reaction proceeds in this second stage reactor (102). Thereafter, the raw material is omitted, but is further supplied to the reactor after the third stage through a heat exchanger. In such a configuration, in order to increase the controllability of the temperature in the reactor 102, not only the number of bases of the reactor 102 and the heat exchanger 103 need to be increased, but also the connection piping and the like are necessary. The cost increases and the device configuration becomes complicated. Moreover, in such a heat exchanger 103, as a refrigerant | coolant for heat exchange, the raw material before reaction in many cases is used before supplying to the reactor 102 of a 1st stage, and the raw material after heat exchange between reaction products is a 1st stage reactor. 102 is supplied. In such a case, there is a problem that the temperature at the outlet of the reactor 102 affects the temperature at the inlet of the reactor 102 and the temperature control in the reactor 102 becomes difficult.

Therefore, Patent Literature 1 divides a catalyst layer in a fixed bed flow-type adiabatic reactor into a plurality of layers, and provides a quenching zone for cooling the raw material between the respective layers, and uses the raw material as a quenching fluid in this quenching zone. A method of feeding into the liquid phase and cooling the inside of the reactor has been proposed. In this apparatus, when the heated raw material is supplied from above, the exothermic reaction advances in the catalyst layer on the upstream side and the temperature of the raw material rises. Then, the raw material is cooled by the quenching fluid in the quench zone, and then flows into the downstream catalyst layer to react similarly. The flow rate of the quenching fluid is adjusted so that the temperature of the raw material is measured at the lower side of the quench zone after supplying the quenching fluid, so that the temperature of this site is in a temperature range suitable for the main reaction.

This apparatus is comprised by one reactor, and since a heat exchanger is unnecessary, cost can be held down. In addition, when an inert component is used as the quenching fluid, purification or separation of the inert component is required, but since the raw material is used, such an operation is unnecessary.

By the way, as an example of the above-mentioned equilibrium reaction involving exotherm, for example, in a reactor for producing dimethyl ether from methanol, when the outlet temperature of the reactor rises slightly higher than the temperature during normal operation, by-products are caused by undesirable side reactions. Is generated. For this reason, it is necessary to stabilize the temperature in a reactor.

In the reactor described in Patent Document 1, the supply amount of the quenching fluid is adjusted based on the temperature at the inlet side of the downstream catalyst layer, and the internal temperature of the reactor is controlled, but the temperature at the inlet side is constant due to the characteristics of the control system. It is difficult to do this, and factors such as the temperature change of the raw material are added, and the temperature change on the inlet side cannot be avoided.

Under such a situation, when the raw material is supplied as a quenching fluid as in Patent Document 1, the raw material increases, so that the equilibrium tilts to the reaction product side. For this reason, since the reaction rate changes sensitively to the inlet temperature change of the catalyst layer, the influence of the inlet temperature of the catalyst layer on the temperature of the outlet side of the reactor becomes large, and as a result, the amplitude of the temperature of the outlet of the reactor becomes large and the conversion rate Also changes. For this reason, the temperature of the reactor outlet is too high to produce by-products due to undesirable side reactions, the purity of the product is lowered, and the temperature of the outlet of the reactor is too low, and the desired yield may not be obtained.

For this reason, the technique which can control the temperature in a reactor by the simple method with the reactor of the simple structure which can enlarge is required.

Japanese Patent Laid-Open No. 2004-298768 (paragraphs 0014, 0020, 0021)

The present invention has been made under such circumstances, and an object thereof is to supply raw materials to an adiabatic reactor and to prepare a target product by an equilibrium reaction involving exothermic heat in the reactor, thereby improving the temperature controllability in the reactor, The present invention provides a technique for suppressing generation of by-products due to an increase and a decrease in yield due to a temperature drop.

Temperature control method inside the reactor of the present invention,

Temperature control performed when the reaction zone is divided into a plurality, and the divided reaction zones are allocated to one or two or more adiabatic reactors to supply raw materials into the adiabatic reactors, and to prepare the target product by an equilibrium reaction involving exothermic heat. In the method,

Supplying a raw material to the reaction zone of the first stage to obtain a reaction product containing the target product,

Next, a step of supplying a mixture containing the reaction product taken out from the reaction zone on the front side and the unreacted raw material to the reaction zone on the rear end side sequentially, and obtaining a reaction product containing the target product, and

Cooling the mixture by supplying and mixing a quenching fluid to the mixture at one or more places between the reaction zones,

The quench fluid is characterized in that it comprises at least one of the same compounds as the target product obtained in a portion of the reaction product obtained in the reaction zone at a later stage than the feed zone of the quench fluid and the adiabatic reactor.

The quench fluid may comprise a portion of the reaction product after cooling the reaction product obtained in the reaction zone of the final stage.

It is preferable that the said several reaction zone is comprised by the catalyst layer, respectively.

Preferably, the reaction zone is divided into three.

The cooling step is preferably performed by adjusting one or more of the supply amount, composition, and temperature of the quenching fluid.

The equilibrium reaction involving exotherm may be a reaction obtained by using methanol as a raw material and obtaining a reaction product containing water and dimethyl ether as a target product. In that case, the quenching fluid preferably contains any one of dimethyl ether and a mixed fluid of dimethyl ether and water.

The reaction apparatus of the present invention

In the reaction apparatus for supplying the raw material into the adiabatic reactor, to produce the target product by the equilibrium reaction with heat generation,

One or more adiabatic reactors, the reaction zone being divided into a plurality, and to which the plurality of divided reaction zones are assigned,

Means for supplying raw materials to the first stage reaction zone,

A quench zone for cooling the mixture by supplying and mixing a quenching fluid to a mixture containing the reaction product and the unreacted raw material interposed between at least one portion between the reaction zones and taken out from the front-side reaction zone, and

And means for supplying a quench zone as a quench fluid a fluid containing a part of the reaction product obtained in the reaction zone at the rear end side of the quench zone and at least one of the same compounds as the target product obtained outside the adiabatic reactor. It features.

The reaction device

Cooling means for cooling the reaction product obtained in the reaction zone of the final stage,

Preferably, the quench fluid is a fluid containing a portion of the reaction product after being cooled by the cooling means.

It is preferable that the said several reaction zone is comprised by the catalyst layer, respectively.

Preferably, the reaction zone is divided into three.

In addition, the reaction apparatus of the present invention preferably includes a control unit for adjusting at least one of the supply amount, the composition and the temperature of the quenching fluid to supply the quenching fluid to the quench zone.

The equilibrium reaction involving exotherm may be a reaction obtained by using methanol as a raw material and obtaining a reaction product containing water and dimethyl ether as a target product. In that case, the quenching fluid preferably contains any one of dimethyl ether and a mixed fluid of dimethyl ether and water.

Method for producing dimethyl ether of the present invention

In the method of dividing the reaction zone into a plurality, the plurality of divided reaction zones are assigned to one or two or more adiabatic reactors, to supply methanol into the adiabatic reactors, and to produce dimethyl ether by dehydration condensation reaction,

Supplying methanol to the first reaction zone to obtain a reaction product containing dimethyl ether and water,

Next, a step of supplying a mixture containing the reaction product taken out of the reaction zone on the front side and unreacted methanol to the reaction zone on the rear end side sequentially, to obtain a reaction product containing dimethyl ether and water, and

Cooling the mixture by supplying and mixing a quenching fluid to the mixture at one or more places between the reaction zones,

The quenching fluid is characterized in that it comprises at least one of dimethyl ether and water obtained in the reaction zone on the rear end side of the supply zone of the quenching fluid, and any one of dimethyl ether obtained outside the adiabatic reactor.

The cooling step is preferably performed by adjusting one or more of the supply amount, composition, and temperature of the quenching fluid.

It is preferable that the said quenching fluid is obtained in the reaction zone of the last stage, and contains either dimethyl ether and water after cooling.

It is preferable that the said several reaction zone is comprised by the catalyst layer, respectively.

Preferably, the reaction zone is divided into three.

The quenching fluid is preferably a part of dimethyl ether after removing water and unreacted methanol, which are byproducts mixed in dimethyl ether.

According to the present invention, the reaction zone is divided into a plurality, and a plurality of divided reaction zones are allocated to one or more adiabatic reactors, so as to feed the raw materials into the adiabatic reactors, and to equilibrate the target object by an equilibrium reaction involving exothermic heat. In the preparation, a mixture containing the reaction product containing the target product and the unreacted raw material obtained by supplying the raw material to the reaction zone of the first stage is sequentially supplied to the reaction zone on the rear stage side in the reaction stage of the first stage. To obtain a reaction product containing, at least one of the reaction zones, a portion of the reaction product obtained at the rear end side of the reaction zone and the target product obtained in the other than the adiabatic reactor by supplying one or more of the same compound as a quenching fluid The mixture is allowed to cool. For this reason, since the amount of reaction products in the mixture increases, the equilibrium is biased toward the raw material side, and the reaction proceeds mildly, so that the change in reaction rate due to the temperature change on the inlet side of the reaction region is small. As a result, the temperature controllability in the reactor is improved, and the production of unexpected by-products due to the temperature rise and the decrease in the yield due to the temperature decrease can be easily suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic block diagram which shows an example of the reaction apparatus for implementing the manufacturing method of this invention.
2 is a schematic view showing an example of a temperature change of raw materials in a reactor in the reaction apparatus described above.
3 is a longitudinal sectional view showing another example of the reaction apparatus described above.
4 is a longitudinal sectional view showing another example of the reaction apparatus described above.
5 is a longitudinal sectional view showing another example of the reaction apparatus described above.
6 is a longitudinal sectional view showing another example of the reaction apparatus described above.
7 is a longitudinal sectional view showing another example of the reaction apparatus described above.
8 is a longitudinal sectional view showing another example of the reaction apparatus described above.
9 is a longitudinal sectional view showing another example of the reaction apparatus described above.
10 is a longitudinal sectional view showing another example of the reaction apparatus described above.
11 is a longitudinal sectional view showing another example of the reaction apparatus described above.
12 is a schematic diagram showing an apparatus used for a comparative example in an embodiment of the present invention.
Fig. 13 is a schematic diagram showing the apparatus used in the comparative example in the embodiment of the present invention.
14 is a schematic diagram showing a conventional apparatus used for a synthesis reaction.
15 is a schematic diagram showing a conventional apparatus used for a synthesis reaction.

EMBODIMENT OF THE INVENTION The reaction apparatus of this invention and embodiment of the temperature control method using this apparatus are demonstrated with reference to FIG. 1 and FIG. 1 shows an outline of the entire production plant including the reaction device 2 for producing a target product. The reaction apparatus 2 is equipped with the vertical reactor 20 which is a fixed bed flow-type adiabatic reactor, for example. One top side of the raw material gas supply pipe 20a, which is a means for supplying raw materials, is connected to the top of the reactor 20, and the heat exchanger 2a and the evaporator 2b are connected to the other end of the raw material gas supply pipe 20a. ) Is connected to a raw material storage source 4 in which a liquid raw material is stored. The evaporator 2b is for vaporizing the liquid raw material to obtain a raw material gas.

One end side of the product gas outlet tube 20b is connected to the bottom of the reactor 20, and the heat exchanger 2a described above is connected to the product gas outlet tube 20b. In this heat exchanger 2a, between the raw material in the raw material gas supply pipe 20a and the mixture containing the reaction product and the raw material in the product gas outlet pipe 20b, the raw material is heated and the mixture is cooled so that heat exchange is performed. Consists of. The other end side of this product gas outlet pipe 20b is connected to the side wall of the 1st distillation column 30 mentioned later.

Inside the reactor 20, a reaction zone necessary for obtaining a target reaction yield, for example, the catalyst layer 22 is divided into an upstream side and a downstream side, and the upstream side reaction zone comprises a first catalyst layer ( It is formed as a 1st reaction region by 22a), and the reaction region of a downstream side is formed as a 2nd reaction region by the 2nd catalyst layer 22b. These catalyst layers 22 (22a, 22b) are supported by a support 23 having a plurality of gas supply holes (not shown).

In the region between the first catalyst layer 22a and the second catalyst layer 22b in the reactor 20, a quench zone Q is provided for cooling the mixture in the reactor 20 by the quenching fluid. A quench fluid supply pipe 24, which is a means for supplying a part of the reaction product as a quench fluid to the quench zone, is connected to the side surface of the reactor 20 in the quench zone Q, and this quench fluid supply pipe 24 is connected. Is connected to the spray part 24a in which the plurality of discharge holes 24b for uniformly distributing and supplying the quenching fluid are formed at a portion proximate to the first catalyst layer 22a on the upper side of the quench zone Q in the reactor 20. It is.

In addition, a temperature detector 29 is provided on the side surface of the reactor 20, and one end side thereof protrudes in the reactor 20, and the temperature of the mixture cooled in the quench zone Q is, for example, the second catalyst layer. It is configured to detect near the upper side of 22b. The control part 3 is connected to this temperature detection part 29, and this control part 3 reacts with the temperature of source gas by the flow control valve 27 mentioned later based on the detection temperature of the temperature detection part 29. As shown in FIG. It is configured to control the flow rate of the quenching fluid so as to be a temperature range suitable for.

At the rear end of the reactor 20, a facility for taking out the target reaction product from the mixture obtained from the reactor 20 and supplying a part of it as a quenching fluid to the reactor 20 is provided. For example, a facility including two distillation columns 30 and 40 for obtaining dimethyl ether as a target is provided.

The first distillation column 30 is for separating and purifying a target substance from a mixture containing unreacted raw materials and a reaction product. A target outlet tube 31, which is a cooling means, is connected to the top of the column, and a lower portion of the discharge tube 32 is connected. One end side is connected. The target object discharged from the target object extraction pipe 31 is taken out of the system as a product, but by the above-mentioned quenching fluid supply pipe 24 whose part is branched from the target object extraction pipe 31, the quench already mentioned above as a quenching fluid. It is configured to return to the band (Q). The flow control valve 27 is provided in the quench fluid supply pipe 24.

The other short side of the discharge pipe 32 mentioned above is connected to the side wall of the 2nd distillation column 40. As shown in FIG. The second distillation column 40 is for separating and refining the unreacted raw material from the mixture from which the object is removed in the first distillation column 30. One end of the raw material discharge pipe 41 is connected to the top of the column, The discharge pipe 42 is connected to this. The other end side of the raw material discharge pipe 41 is connected to the raw material gas supply pipe 20a on the upstream side of the evaporator 2b described above, and is configured to return and reuse unreacted raw material. The discharge pipe 42 is for disposing of by-products, impurities, and the like remaining after the target and unreacted raw materials are removed from the mixture, and these are discharged out of the system.

Subsequently, the method of operating the reaction apparatus 2 described above will be described with reference to FIGS. 1 and 2.

The liquid raw material consisting of one substance or a plurality of substances is vaporized in an evaporator 2b installed at the front end, and between the mixture containing the unreacted raw material and the reaction product taken out of the reactor 20 in the heat exchanger 2a. Heat exchange is performed and heated to temperature T1.

Thereafter, the source gas is supplied to the reactor 20 via the source gas supply pipe 20a, and the inside of the reactor 20 flows from the top to the bottom. In the first catalyst layer 22a, a reaction product including the target product is produced by the equilibrium reaction of the following formula (1), and the gas is a mixture of the reaction product and the unreacted raw material gas.

[Equation 1]

Source gas ⇔ Reaction product (object (+ by-product)) + heat of reaction

By the heat of reaction generated at this time, the temperature of the gas of the mixture rises to become the temperature T2.

When manufacturing dimethyl ether, methanol which is a liquid raw material vaporizes, and dimethyl ether and water are produced | generated by the equilibrium reaction of following formula (2) in the 1st catalyst layer 22a.

[Equation 2]

2CH ₃ OH ⇔ CH ₃ OCH ₃ + H ₂ O + ΔH

ΔH = -23.4 kJ / mol

Subsequently, when the quenching fluid is supplied from the spray section 24a in the quench zone Q, the gases of the mixture which has become a high temperature T2 by the exothermic reaction of the quenching fluid and the catalyst layer 22a at the front end are mixed with each other. , The temperature of the mixture becomes T3. This quenching fluid is a fluid containing a part of the reaction product obtained in the reaction apparatus 2, and is supplied in a liquid phase or a gas phase. In the case of producing dimethyl ether, for example, dimethyl ether which is a gas is used as the quenching fluid.

By supplying a part of reaction product as a quenching fluid in this way, in the 2nd catalyst layer 22b, since the quantity of reaction products of the right side of said Formulas 1 and 2 increases, the equilibrium reaction of Formulas 1 and 2 is carried out. Since the reaction which biases toward the raw material side and produces a target product is suppressed, the above reaction proceeds gently.

The gas of the mixture thus cooled, more particularly the mixture comprising the quenching fluid, is supplied to the second catalyst layer 22b and the reaction product is produced mildly by the same reaction in the second catalyst layer 22b. The mixture containing this reaction product and unreacted raw material rises to temperature T4 by reaction heat which arises in reaction in this 2nd catalyst layer 22b.

Thereafter, the mixture is taken out from the reactor 20 through the product gas outlet pipe 20b, and heat exchange is performed between the raw materials in the heat exchanger 2a.

In the following description, a flow of the dimethyl ether, which is a reaction product discharged from the reactor 20 and water and methanol as an unreacted raw material, is described in the first distillation column 30. It is supplied to and dimethyl ether which is a target product is separated and purified. The purified dimethyl ether separated from the mixture is taken out from the target blowout pipe 31, is radiated to the pipe wall of the target blowout pipe 31, and so on to a temperature equal to or lower than the temperature T2 previously described, and partly through the quenching fluid supply pipe 24. Return to reactor 20 as quench fluid. The remaining dimethyl ether is taken out of the system as a product.

The mixture from which dimethyl ether has been removed is discharged from the lower side of the first distillation column 30 to be supplied to the second distillation column 40, and methanol, which is an unreacted raw material, is separated and purified from the second distillation column 40. As described above, the unreacted raw material is returned to the raw material gas supply pipe 20a and supplied again to the reactor 20 together with the raw material supplied from the raw material storage source 4. In addition, waste that is a by-product from which the target and unreacted raw materials are removed, in this example, water is discharged out of the system.

Here, the temperature T3 at the inlet of the catalyst layer 22b is detected by the temperature detecting unit 29, and the supply flow rate of the quenching fluid is controlled via the control unit 3 and the flow regulating valve 27 in accordance with the temperature detected value. Although the inlet temperature T3 of the catalyst layer 22b is stabilized, it is unavoidable that the inlet temperature T3 fluctuates by a specific fluctuation range. However, in the present invention, since the reaction product is used as the quenching fluid, as described above, since the equilibrium reaction is biased toward the raw material side and the reaction in which the target product is produced is suppressed, the catalyst layer with respect to the outlet temperature T4 of the catalyst layer 22b. The influence of the inlet temperature T1 of 22a becomes small. That is, since the change of reaction rate to a target product becomes small with respect to the change of the inlet temperature T1 of the catalyst layer 22a, the change of the outlet temperature T4 of the catalyst layer 22b becomes insensitive, and the amplitude of a conversion rate becomes small.

According to the above-described embodiment, the first reaction region and the second reaction region for reacting the raw materials in supplying the raw materials into the adiabatic reactor 20 and producing the target product by an equilibrium reaction involving heat generation. A quench zone (Q) was installed in between, and a part of the reaction product taken out of the second reaction zone was cooled and supplied as a quenching fluid to cool the mixture including the raw material and the reaction product. have. For this reason, as already mentioned above, since the amount of reaction products in the mixture increases, the equilibrium is biased toward the raw material side, and the reaction proceeds smoothly, so that temperature control in the reactor 20 is facilitated, and as a result, the unexpected rise due to the temperature rise. Not only can the formation of by-products be suppressed, but the decrease in yield due to temperature decrease can be suppressed. In addition, the caulking of the catalyst can be suppressed, and the life of the catalyst can be extended. In addition, it is possible to suppress an abrupt temperature rise (runaway reaction) in the reaction device 2 and to operate the reaction device 2 safely. Therefore, compared with the existing method, the structure of the reactor 20 can be simplified and large size becomes easy, and the number of parts which comprise the reactor 20 is few.

The quenching fluid may be a gas or a liquid. In the case of using a quenching fluid, which is a gas, since latent heat of evaporation cannot be used, it is necessary to increase the amount of supply compared with the case of using liquid, but the amount of reaction products in the reactor 20 increases, so that the reaction rate is increased. The inhibitory effect is great. On the other hand, in the case of using a quenching fluid that is a liquid, the temperature of the mixture can be lowered with a smaller supply amount than in the case of using a gas. For example, when the supply amount of raw materials is small and the temperature rise of the mixture by the reaction is small, the reaction product may be supplied as a quenching fluid without cooling. Even in this case, the reaction rate is suppressed because the amount of the reaction product in the reactor 20 increases.

In addition, although the catalyst layer 22 was made into two layers in the above-mentioned example, as shown, for example in FIG. 3 and FIG. 4, more catalyst layers may exist. FIG. 3 shows a reactor 20 with three catalyst layers 22a, 22b, 22c, and FIG. 4 with five catalyst layers 22a, 22b, 22c, 22d, 22e. Also in FIGS. 3 and 4, in the quench zone Q between the catalyst layers 22, the temperature of the mixture is detected by the temperature detector 29, and the flow rate of the quenching fluid supplied from the sprayer 24a is adjusted. do. Also in this reactor 20, reaction advances in the state in which reaction rate was suppressed by the quenching fluid similarly to the above-mentioned example. Thus, by making the catalyst layer 22 into multiple layers, the effect similar to the above-mentioned example is acquired.

In addition to the case where a plurality of catalyst layers 22 are provided in one reactor 20, for example, as shown in FIGS. 5 and 6, the reactor 20 provided with one catalyst layer 22 is provided. This condenser may be connected. 5 and 6 show examples in which three and five reactors 20 are connected, respectively, and a quenching fluid supply pipe 24 is provided in the product gas outlet pipe 20b connecting the respective reactors 20. Is connected. In addition to the reactor 20, for example, as shown in FIG. 7, FIG. 8, the reactor 20 provided with one or more catalyst layers 22 can also be connected in combination. FIG. 7 shows an example in which a reactor 20 provided with one catalyst layer 22 and a reactor 20 provided with two catalyst layers 22a and 22b are connected in series. FIG. 8 shows an example in which a reactor 20 provided with two catalyst layers 22a and 22b and a reactor 20 provided with three catalyst layers 22a, 22b and 22c are connected in series. Similarly, between these catalyst layers 22, it is comprised so that a quench fluid may be supplied in a quench zone Q. FIG. Also in such a structure, the effect similar to the above-mentioned example is acquired.

In each of the above examples, it is preferable to provide a quench zone Q between each of the catalyst layers 22 and 22, but, for example, when the amplitude of the temperature is small, etc., It is also possible to reduce the number, ie there is at least one or more quench bands (Q). FIG. 9 shows an example in which the quench zone Q between the second catalyst layer 22b and the third catalyst layer 22c is omitted from the upstream side in the reactor 20 shown in FIG. 4 described above. have. The same effect can be obtained also in such a reactor 20.

In addition, in the above-mentioned example, although the target object in system was used as a quenching fluid, the compound similar to the target object out of a system can also be used as a quenching fluid. For example, as shown in FIG. 10, a plurality of reaction apparatuses 2 may be provided, and a quenching fluid may be supplied from one reaction apparatus 2 to the other reaction apparatus 2. In this case, the quench fluid supply pipe 24 of the other reaction device 2 is connected to the target object extraction pipe 31 of the one reaction device 2. In addition, in the above FIGS. 3-10, the same code | symbol is attached | subjected about the structure similar to FIG. The unreacted raw material may be mixed in the target object which is these quenching fluids.

In addition to using the target substance as the quenching fluid, for example, when a reaction product (by-product) other than the target substance is produced from the raw material (in addition to the target substance, when there is a substance produced on the right side of Equation 1), the reaction product May be used as a quenching fluid. For example, in the reaction of obtaining dimethyl ether, water may be used as the quenching fluid. In that case, as shown in FIG. 11, the whole quantity of the target object is taken out from the target extraction pipe 31, and a part of waste is returned to the quench zone Q as a quenching fluid. Also in this case, since the reaction is suppressed by increasing the reaction product on the right side of the equations (1) and (2) as in the above example, the reaction proceeds gently, and the amplitude of the mixture temperature at the outlet of the reactor 20 is small. Lose. In addition, in FIG. 11, the same code | symbol is attached | subjected about the structure same as FIG. 1 mentioned above.

In addition, the target product may be used as a quenching fluid together with this by-product, for example, dimethyl ether and water may be used as a quenching fluid in the reaction which obtains dimethyl ether from methanol. Dimethyl ether outside the system can also be used as a quenching fluid.

In each of the above examples, although a compound other than the same system as the reaction product or the target product was used as the quenching fluid, the quenching fluid may not be included in the quenching fluid as long as the reaction product contains a compound outside the same system as the reaction product or the target product. The reacted raw material may be included. In that case, for example, in FIG. 1, one end side of the branch pipe (not shown) where the valve is opened is connected to the raw material discharge pipe 41, and the other end side of the branch pipe is quenched fluid supply pipe 24. The unreacted raw material can also be actively used as part of the quenching fluid by connecting to and adjusting the opening of this valve.

In addition, in each said example, although the flow volume of a quenching fluid is controlled by the control part 3, the inlet temperature T3 of the reactor 20 is stabilized, but the flow volume of a quenching fluid is made constant and the control part 3 is interposed. Inlet temperature by adjusting the opening degree of the valve of the branch pipe and the flow control valve 27 mentioned above, for example, and adjusting the ratio of the compound of the system other than the reaction product contained in the quenching fluid and the target object, ie, the composition of the quenching fluid. It is also possible to stabilize T3. In addition, a cooling mechanism (not shown) is provided in the quenching fluid supply pipe 24, the flow rate of the quenching fluid is made constant, and the temperature of this quenching fluid is adjusted through the control section 3, whereby the inlet temperature T3 of the reactor 20 is reduced. It can also be stabilized. Further, the inlet temperature T3 of the reactor 20 may be stabilized by controlling a plurality of the flow rates of the quenching fluid, the composition of the quenching fluid, and the temperature of the quenching fluid in combination through the control unit 3.

The temperature control method and the reaction apparatus of the object of the present invention, when producing the target object by the equilibrium reaction with exothermic, as described above, for example, of dimethyl ether by dehydration from methanol in the examples described later It can also be applied to a synthesis reaction or a synthesis reaction of ammonia from hydrogen and nitrogen. Moreover, in addition to the said synthesis reaction, it can apply to the equilibrium reaction with exothermic reaction, for example, oxidation reaction, hydrogenation reaction, and other reaction, and can also apply to these reaction in a liquid phase.

<Examples>

The experiment performed to confirm the effect of the method of the present invention will be described below. In this example, experiments were conducted in which methanol was used as the starting material, and dimethyl ether was obtained as a target by an equilibrium reaction involving exotherm in the above-mentioned formula (2).

In addition, although the standard conditions are set in each of the following experiments, these standard conditions are conditions set so that the conversion rate of methanol in the final catalyst layer outlet and the temperature of each catalyst layer outlet may be the same in each standard condition.

(Example 1)

As an apparatus for performing the above reaction, a thermometer is used at the inlet of the reactor 20 and the inlets and outlets of the catalyst layers 22a and 22b, respectively, using the reaction apparatus 2 shown in FIG. 1 described above. Was installed.

In this reaction apparatus (2), methanol of the flow rate F1 was supplied, dimethyl ether was supplied to the quench zone (Q) at flow rate F2 as a quenching fluid, and unreacted methanol was returned to flow rate F3. About water which is a by-product, it discharged from the discharge pipe 42 mentioned above. In addition, each flow volume F1-F3 has shown the mass flow volume of each fluid.

As experimental conditions, each condition was determined as follows so that conversion and temperature of methanol at the outlet of the reactor 20 might be 75%, and 340 degreeC, respectively, and these conditions were made into the standard conditions. In addition, the raw material temperature of the inlet of the reactor 20 was changed by 1 degreeC up and down from the above-mentioned standard conditions, and about the conditions other than that, the experiment was performed on the same conditions as the standard conditions. Then, at each condition, the outlet temperature of the reactor 20 (temperature at the outlet side of the second catalyst layer 22b) and the conversion rate of methanol at the outlet of the reactor 20 were compared. The flow rate of the flow rate F2 of dimethyl ether as the quenching fluid and the flow rate F3 of methanol as the unreacted raw material returned from the raw material discharge pipe 41 were set to the same flow rate as the standard conditions.

(Standard condition)

Inlet temperature of reactor 20: 279 ° C

Pressure at the inlet of reactor 20: 1.55 MPa (gauge pressure)

Ratio of quenching amount to flow rate of raw material (F2 / (F1 + F3)): 0.18

Quenching dimethyl ether conditions: 1.5 MPa (gauge pressure)

                        Dimethyl ether saturated steam (100%)

(Experiment result)

The experimental results are shown in Table 1 below.

As a result, the temperature in the reactor 20 was also changed with the change of the temperature of the inlet side of the reactor 20 (the temperature at the inlet side of the first catalyst layer 22a). Moreover, it turned out that the temperature change of the outlet of the reactor 20 becomes larger than the temperature change of the inlet of the reactor 20. The conversion rate increased as the temperature in the reactor 20 increased, and the conversion rate decreased as the temperature in the reactor 20 decreased.

(Comparative Example 1-1)

Subsequently, as Comparative Example 1-1, distillation towers 30 and 40 were connected to an apparatus in which a heat exchanger 103 was established between the plurality of reactors 102 and 102 of FIG. It was done. This apparatus is shown in FIG. In addition, the same code | symbol is attached | subjected to the site | part of the structure similar to FIG. 1 mentioned above already. Also in this apparatus, the temperature of the raw material of each inlet and outlet of the upstream reactor (first reactor) 102 and the downstream reactor (second reactor) 102 was measured.

In this apparatus, the raw material gas after vaporizing in the evaporator 2b is supplied from the supply path 200 to the heat exchanger 103, and in this heat exchanger 103, this raw material gas and the reactor 102 of an upstream side. The heat exchange was performed (cooling the mixture) between the raw material and the mixture containing the reaction product, which became hot due to the reaction at h). In addition, the source gas after heat exchange (heating) in this heat exchanger 103 was made to return to the source gas supply line 20a in front of the reactor 102 of an upstream. In addition, the flow of raw materials, reaction products, etc. other than the fluid supplied to this heat exchanger 103 was made similarly to the reaction apparatus 2 of FIG. 1 mentioned above.

In the same manner as in Example 1, the following conditions were determined so that the conversion rate of methanol and the temperature of the raw material at the outlet of the downstream reactor 102 were 75% and 340 ° C, respectively, and these conditions were the standard conditions. It was. In addition, similarly, the raw material temperature of the inlet upstream side of the reactor 102 was changed by 1 degreeC up and down from standard conditions, and the conditions other than that were experimented on the same conditions as standard conditions.

And similarly, the temperature of the outlet of the downstream reactor 102 was measured, and the conversion rates were compared. In addition, the quantity of methanol returned from the raw material discharge pipe | tube 41 was made into the same flow volume as standard conditions. The heat exchange amount (heat transfer amount) between the quenching fluid and the mixture in the heat exchanger 103 is not changed even when the temperature of the inlet of the reactor 102 on the upstream side is changed.

(Standard condition)

Inlet temperature of reactor 102: 279 ° C

Pressure at the inlet of reactor 20: 1.55 MPa (gauge pressure)

(Experiment result)

The experimental results are shown in Table 2 below.

As a result, similarly to Example 1, the temperature and the conversion rate of each part were changed according to the temperature change on the upstream side, but the amount of change was more than the amount of change in Example 1. Therefore, in Example 1, it turns out that reaction is suppressed by using dimethyl ether which is a reaction product as a quenching fluid, and the controllability of the internal temperature and conversion ratio of the reactor 20 is improved.

(Comparative Example 1-2)

Next, experiment was performed using the apparatus of FIG. 13 as an apparatus of the structure similar to the apparatus of patent document 1 mentioned above. Although this apparatus is equipped with the reactor 300 of the structure substantially the same as the reactor 20 of FIG. 1, it is comprised so that the liquid raw material may be supplied from the raw material quench supply path 200 as a quenching fluid. 13, the same code | symbol was attached | subjected about the site | part of the structure similar to FIG.

In the same manner as in the above experiment, the following conditions were determined so that the conversion ratio of methanol and the temperature of the raw material at the outlet side of the reactor 300 were 75% and 340 ° C, respectively, and the conditions were set as standard conditions. The experiment was performed by changing the temperature at the inlet side of 1) up and down by 1 degreeC. Also in this case, the flow rate of the unreacted methanol returned from the raw material discharge pipe 41 and the flow rate of the quenching fluid were made constant. Also in this example, F1 is the methanol supply amount, F2 is the quenched methanol supply amount, and F3 is the recycled methanol flow rate.

(Standard condition)

Inlet temperature of reactor 300: 279 ° C

Pressure at the inlet of reactor 300: 1.55 MPa (gauge pressure)

Ratio of Quenching Amount to Flow of Raw Material (F2 / (F1 + F3)): 0.09

Quenched methanol conditions: 1.6 MPa (gauge pressure), liquid at boiling point

(Experiment result)

The experimental results are shown in Table 3 below.

Also in this result, although the temperature and conversion rate of each part inside the reactor 300 were changed by the temperature of the inlet of the reactor 300, the change amount was larger than Example 1 similarly to the comparative example 1-1.

From the above results, when the raw material is used as the quenching fluid, the equilibrium reaction is biased toward the reaction product side, and the reaction rate to the target product is increased, so that the calorific value increases, and as a result, the temperature of the mixture at the outlet of the reactor 20 is increased. Although the fluctuation becomes large, it turns out that by using a part of reaction product as a quenching fluid, reaction to the target product can be suppressed and the amplitude of the temperature of the mixture in the outlet of the reactor 20 can be made small.

(Example 2)

Next, as shown in FIG. 3 mentioned above, when the catalyst layer 22 was made into three layers, the experiment for checking how the temperature and the conversion rate of the exit of the reactor 20 change is performed.

In the experiment, the reactor 20 shown in FIG. 3 was used, and the conditions were determined as follows so that the conversion rate and the temperature of methanol at the outlet of the reactor 20 were 75% and 340 ° C, respectively. It was made. In addition, the temperature of the raw material of the inlet of the reactor 20 was similarly changed up and down by 1 degreeC, and the conditions other than that were experimented on the same conditions as a standard condition. And the temperature of the inlet and outlet of each catalyst layer 22 of the reactor 20 in each condition was measured, and the conversion rate of methanol in the outlet of the reactor 20 was compared. The flow rate of the flow rate F2 of dimethyl ether as the quenching fluid and the flow rate F3 of methanol as the unreacted raw material returned from the raw material discharge pipe 41 were set to the same flow rate as the standard conditions.

(Standard condition)

Inlet temperature of reactor 20: 279 ° C

Pressure at the inlet of reactor 20: 1.55 MPa (gauge pressure)

Ratio of quenching amount to flow rate of raw material (F2 / (F1 + F3)): 0.18

Quenching dimethyl ether conditions: 1.5 MPa (gauge pressure)

                        Dimethyl ether saturated steam (100%)

(Experiment result)

The experimental results are shown in Table 4 below.

As a result, by using the product as a quenching fluid, even if the temperature at the inlet side of the reactor 20 changes, as in the result of Experimental Example 1, it is possible to suppress the change in temperature and the conversion rate at the outlet side of the reactor 20. I knew it was.

Claims (20)

Temperature control performed when dividing a reaction zone into a plurality, and a plurality of divided reaction zones are assigned to one or more adiabatic reactors to supply raw materials into the adiabatic reactors, and to produce a target product by an equilibrium reaction involving exothermic heat. Way,
Supplying a raw material to the reaction zone of the first stage to obtain a reaction product containing the target product,
Next, a step of supplying a mixture containing the reaction product taken out from the reaction zone on the front side and the unreacted raw material to the reaction zone on the rear end side sequentially, and obtaining a reaction product containing the target product, and
Cooling the mixture by supplying and mixing a quenching fluid to the mixture at one or more places between the reaction zones,
The quenching fluid comprises at least one of a portion of the reaction product obtained in the reaction zone at the rear end side of the supply zone of the quenching fluid and at least one of the same compounds as the target product obtained outside the adiabatic reactor. Control method. The method of claim 1, wherein the quenching fluid comprises a portion of the reaction product after cooling the reaction product obtained in the reaction zone of the final stage. The method of controlling temperature inside a reactor according to claim 1, wherein the plurality of reaction zones are each composed of a catalyst layer. 2. The method of claim 1, wherein the divided reaction zones are three. The method of claim 1, wherein the cooling step is performed by adjusting at least one of the supply amount, the composition, and the temperature of the quenching fluid. The temperature control method inside a reactor according to claim 1, wherein the equilibrium reaction involving exotherm is a reaction for obtaining a reaction product containing water and dimethyl ether as a target, using methanol as a raw material. The method of claim 1, wherein the quenching fluid comprises any one of dimethyl ether and a mixed fluid of dimethyl ether and water. It is a reaction apparatus which supplies a raw material to an adiabatic reactor, and manufactures a target object by the equilibrium reaction with heat generation,
One or more adiabatic reactors, the reaction zone being divided into a plurality, and to which the plurality of divided reaction zones are assigned,
Means for supplying raw materials to the first stage reaction zone,
A quench zone for cooling the mixture by supplying and mixing a quench fluid to a mixture containing the reaction product and the unreacted raw material interposed between at least one portion between the reaction zones and taken out from the reaction zone on the front end, and
And means for supplying a quench zone as a quench fluid a fluid containing a part of the reaction product obtained in the reaction zone at the rear end side of the quench zone and at least one of the same compounds as the target product obtained outside the adiabatic reactor. Reactor characterized in that. The method according to claim 8, further comprising cooling means for cooling the reaction product obtained in the reaction zone of the final stage,
The quenching fluid is a fluid comprising a portion of the reaction product after being cooled by the cooling means. The reaction apparatus according to claim 8, wherein the plurality of reaction zones are each composed of a catalyst layer. The reaction apparatus of claim 8, wherein the reaction zone is divided into three. The reaction apparatus according to claim 8, further comprising a control unit for adjusting at least one of the supply amount, the composition, and the temperature of the quenching fluid to supply the quenching fluid to the quench zone. The reaction apparatus according to claim 8, wherein the equilibrium reaction involving exotherm is a reaction of obtaining a reaction product containing water and dimethyl ether as a target, using methanol as a raw material. The reaction apparatus of claim 8, wherein the quenching fluid comprises any one of dimethyl ether and a mixed fluid of dimethyl ether and water. Is a method of dividing the reaction zone into a plurality, the plurality of divided reaction zones are assigned to one or more adiabatic reactors to supply methanol into the adiabatic reactors, and to produce dimethyl ether by dehydration condensation reaction,
Supplying methanol to the reaction zone of the first stage to obtain a reaction product containing dimethyl ether and water,
Next, a step of supplying a mixture containing the reaction product taken out of the reaction zone on the front side and unreacted methanol to the reaction zone on the rear end side sequentially, to obtain a reaction product containing dimethyl ether and water, and
Cooling the mixture by supplying and mixing a quenching fluid to the mixture at one or more places between the reaction zones,
The quenching fluid comprises at least one of dimethyl ether and water obtained in the reaction zone on the rear end side of the supply zone of the quenching fluid, and any one of dimethyl ether obtained in the other than the adiabatic reactor. Way. The method for producing dimethyl ether according to claim 15, wherein the cooling step is performed by adjusting at least one of the supply amount, the composition, and the temperature of the quenching fluid. The method for producing dimethyl ether according to claim 15, wherein the quenching fluid contains any one of dimethyl ether and water after cooling in the reaction zone at the final stage. The method for producing dimethyl ether according to claim 15, wherein the plurality of reaction zones are each composed of a catalyst layer. 16. The process for producing dimethyl ether according to claim 15, wherein the divided reaction zones are three. The method for producing dimethyl ether according to claim 15, wherein the quenching fluid is part of dimethyl ether after removing water and unreacted methanol which are by-products mixed in dimethyl ether.

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