JP2004307435A - Method for preparing dimethyl ether and apparatus for carrying out synthetic reaction of dimethyl ether - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for preparing dimethyl ether in which contact area of a raw material gas with a suspended catalyst solution is enlarged, and an apparatus for carrying out synthetic reaction for the dimethyl ether. <P>SOLUTION: The method for preparing the dimethyl ether comprises directly bringing the raw material gas into contact with the suspended catalyst solution to carry out a reaction in a reaction tower. In the suspended catalyst solution in the reaction tower, at least one of pulse, micro wave vibration and ultrasonic wave vibration is superimposed on a continuous phase of the catalyst solution to promote dispersal of foam of a disperse phase gas. The raw material gas increases a vapor-liquid interfacial area by contact with foam of the disperse phase gas and thereby the reaction is promoted in the reaction tower in which the suspended catalyst solution is reacted. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing dimethyl ether and a dimethyl ether synthesis reaction apparatus for producing dimethyl ether by increasing the contact area between a raw material gas and a suspended catalyst solution.
[0002]
[Prior art]
FIG. 3 is a diagram for explaining a conventional dimethyl ether production system. In FIG. 3, the raw material 30 which consists of coal bed methane, a propane gas, oxygen, steam etc. is put into the production | generation tower 31, and reacts in this inside. Of the generated synthesis gas, part of the carbon dioxide gas is compressed outside by the compressor 32 together with carbon monoxide gas and hydrogen gas.
[0003]
The compressed synthesis gas is put into an absorption tower 33, and carbon dioxide gas is absorbed and released to the outside. After that, in the reaction tower 34, the synthesis gas is brought into contact with a catalyst and is subjected to reaction conditions such as a temperature of 250 ° C. to 480 ° C. to become a reacted liquid and an unreacted gas.
[0004]
Next, the gas-liquid separation tower 35 separates the unreacted gas and the reacted liquid. The unreacted gas is sucked by the suction device 36 and then returns to the reaction tower 34 to react with the raw material gas again. The liquid reacted in the reaction tower 34 is further separated into carbon dioxide gas by the next separation tower 37. Thereafter, the carbon dioxide gas is purged.
[0005]
The liquid separated by the separation tower 37 is distilled by the distillation tower 38, and the gas is collected as dimethyl ether (DME) 39, and the remainder becomes methanol 40.
[0006]
The dimethyl ether steam reforming catalyst described in JP-A-2002-263504 is a method in which an acid is added to a metal alkoxide to form a sol, the sol is evaporated to dryness, a gel material is fired, and then the fired gel is reduced. It was produced by processing.
[0007]
[Patent Document 1]
JP 2002-263504 A
[0008]
In the method for producing dimethyl ether described in JP-A-2002-155004, a gas obtained by mixing a gas A containing hydrogen gas and methane gas and a gas B containing carbon monoxide gas is suspended in a slurry in a solvent. In the method for producing dimethyl ether in contact with the catalyst, the gas A was previously reformed with carbon dioxide or steam to increase the hydrogen gas concentration and reduce the methane gas concentration.
[0009]
[Patent Document 2]
JP2002-155004
[0010]
[Problems to be solved by the invention]
The dimethyl ether production system shown in FIG. 3 has not been devised to forcibly increase the contact area between the raw material gas and the catalyst only by setting the temperature at which reaction is easy. Similarly, the examples of Patent Document 1 and Patent Document 2 do not forcibly increase the contact area between the source gas and the catalyst.
[0011]
In order to solve the above problems, the present invention supplies a raw material gas that is a dispersed phase from below the continuous phase in the suspended catalyst solution, and the suspended catalyst solution is buoyant by the buoyancy of the raw material gas. Ascending in the phase, the size of bubbles is increased based on the interfacial tension between the raw material gas and the suspended catalyst solution.
[0012]
The present invention provides a method for producing dimethyl ether, in order to increase a reaction rate of a raw material gas and a suspended catalyst solution, by increasing an interface area between the raw material gas and the suspended catalyst solution, This increases the mass transfer coefficient of the interface in the catalyst solution.
[0013]
In order to increase the mass transfer rate at the heterogeneous interface in the suspension contact reaction apparatus of the suspended catalyst solution, the present invention superimposes the pulsation or vibration on the suspended catalyst solution side which is a continuous phase. It is an object of the present invention to provide a dimethyl ether production method and a dimethyl ether synthesis reaction apparatus that increase the interfacial area due to dispersion of a suspended catalyst solution and increase the reaction rate with a raw material gas.
[0014]
The present invention provides a method for producing dimethyl ether, which is achieved by superimposing pulsation or the like on the continuous phase side of a reactor as a means for solving two problems of dispersion of gas bubbles and an increase in mass transfer coefficient of a heterogeneous interface, and An object is to provide a dimethyl ether synthesis reactor.
[0015]
The present invention forcibly disperses the bubbles of the catalyst solution in which the raw material gas is suspended in the reaction tower, thereby increasing the area of the heterophase interface and further increasing the mass transfer coefficient between the raw material gas and the catalyst solution interface. It is an object of the present invention to provide a method for producing dimethyl ether and a dimethyl ether synthesis reaction apparatus.
[0016]
[Means for Solving the Problems]
(First invention)
The dimethyl ether production method of the first invention is to produce dimethyl ether by directly contacting a raw material gas and a suspended catalyst solution, and suspended in a reaction tower where the raw material gas and the suspended catalyst solution react. The reaction rate is increased by increasing the interfacial area of the raw material gas and the catalyst solution by superimposing at least one of pulsation, microwave vibration, and ultrasonic vibration on the continuous phase of the catalyst solution to promote foam dispersion of the dispersed phase gas. Is characterized in that dimethyl ether is produced.
[0017]
(Second invention)
The dimethyl ether production method of the second invention is to produce dimethyl ether by directly contacting a raw material gas and a suspended catalyst solution, and suspended in a reaction tower where the raw material gas and the suspended catalyst solution react. It is characterized in that dimethyl ether is produced by increasing the reaction rate by superimposing at least one of pulsation, microwave vibration and ultrasonic vibration on the continuous phase of the catalyst solution to increase the mass transfer coefficient of the heterogeneous interface. .
[0018]
(Third invention)
The dimethyl ether synthesis reactor according to the third aspect of the present invention is a pulsation in a reaction tower in which a raw material gas and a suspended catalyst solution are in contact, a catalyst solution suspension in the reaction tower, and a continuous phase of the suspended catalyst solution. And at least pulsation generating means for imparting.
[0019]
(Fourth invention)
A dimethyl ether synthesis reaction apparatus according to a fourth aspect of the invention is a reaction tower in which a raw material gas and a suspended catalyst solution are in contact with each other, a catalyst solution suspension in the reaction tower, and a continuous phase of the suspended catalyst solution. And at least microwave generation means for providing
[0020]
(Fifth invention)
A dimethyl ether synthesis reaction apparatus according to a fifth aspect of the present invention includes a reaction tower in which a raw material gas and a suspended catalyst solution are in contact with each other, a catalyst solution suspension in the reaction tower, and a continuous phase of the suspended catalyst solution. And at least an ultrasonic wave generating means for providing the above.
[0021]
(Sixth invention)
In the dimethyl ether synthesis reactor according to the sixth aspect of the invention, the reaction tower is characterized in that a countersink is installed in the continuous phase of the suspended catalyst solution.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
(First invention)
In the dimethyl ether production method of the first invention, in a reaction tower, a raw material gas composed of coal bed methane gas, propane gas, oxygen, steam and the like is brought into direct contact with a suspended catalyst solution to cause a reaction. The reaction conditions are, for example, 250 ° C. to 480 ° C. In the suspended catalyst solution in the reaction tower, at least one of pulsation, microwave vibration, and ultrasonic vibration is superimposed on the continuous phase to promote foam dispersion of the dispersed phase gas.
[0023]
In the reaction tower where the suspended catalyst solution reacts, the source gas comes into contact with the foam of the dispersed phase gas, increases the gas-liquid interface area, and promotes the reaction. Since the dimethyl ether production method of the first invention increases the gas-liquid interface area and promotes the reaction, dimethyl ether can be produced efficiently.
[0024]
(Second invention)
The method for producing dimethyl ether of the second invention is that the mass transfer coefficient of the heterogeneous interface is increased by superimposing at least one of pulsation, microwave vibration, and ultrasonic vibration on the continuous phase of the suspended catalyst solution. Different from the first invention. The dimethyl ether production method of the second invention is the same as the first invention in that dimethyl ether can be produced efficiently because the reaction is promoted by increasing the gas-liquid interface area.
[0025]
In the second invention, even if the suspended catalyst solution does not become foamy, it is sufficient that the mass transfer coefficient of the substance is large at the heterogeneous interface between the raw material gas and the suspended catalyst solution.
[0026]
(Third invention)
In the dimethyl ether synthesis reactor of the third invention, in the reaction tower, the raw material gas and the suspended catalyst solution are in contact with each other, and the reaction is accelerated by a predetermined reaction temperature. The catalyst in the reaction tower is suspended together with the solution to become a catalyst solution suspension. The continuous phase of the suspended catalyst solution is given pulsation by means of pulsation generating means including a pump such as a piston and a cylinder. The pulsation generating means is not limited to the shape and structure as long as it can give pulsation to the suspended catalyst solution.
[0027]
(Fourth invention)
The fourth invention is different from the third invention in that the means for applying vibration to the continuous phase of the suspended catalyst solution is a microwave generating means. The microwave generating means is preferably 300 MHz to 30 GHz. In particular, 2450 MHz is used for microwave ovens and can be achieved with off-the-shelf products.
[0028]
(Fifth invention)
The fifth invention is different from the third and fourth inventions in that the means for applying vibration to the continuous phase of the suspended catalyst solution is an ultrasonic wave generating means.
[0029]
(Sixth invention)
According to the sixth aspect of the present invention, a countersink is installed in the continuous phase of the suspended catalyst solution. The plate can increase the gas-liquid interface area and promote the reaction in combination with the vibration applied to the continuous phase of the suspended catalyst solution.
[0030]
【Example】
FIG. 1 is a schematic exaggerated schematic diagram for explaining a reaction tower for reacting a suspended catalyst solution and a raw material gas in the first embodiment of the present invention. In FIG. 1, a reaction tower 11 is provided with a raw material gas transport pipe 12 at the lower part and a reactant transport pipe 13 at the upper part. Further, the reaction tower 11 is provided with a catalyst solution insertion port 141 below, and fills the catalyst solution suspended therein.
[0031]
Inside the reaction tower 11 is provided a cooling pipe 15 through which cooling water 151 for cooling reaction heat flows. Above the reaction tower 11, an overflow tank 16 for the catalyst solution is provided, and the overflowed catalyst solution exits from the overflow solution outlet 161.
[0032]
Furthermore, a pulsation device 17 that pulsates the catalyst solution is provided below the reaction tower 11. The pulsation device 17 includes, for example, a cylinder 171 and a piston 172, and the suspended catalyst solution 14 in the reaction tower 11 is stirred by the vertical movement of the piston 172. Further, the pulsation device 17 can be replaced with a bellows type or other known or well-known techniques in addition to the cylinder and piston types.
[0033]
At the same time, when the raw material gas 142 that is a dispersed phase is supplied from the lower side of the reaction tower 11 to the suspended catalyst solution 14 that is a continuous phase, the suspended catalyst solution 14 is caused by the buoyancy of the raw material gas 142. Ascending in the phase, the bubble size based on the interfacial tension between the raw material gas 142 and the suspended catalyst solution 14 is increased.
[0034]
The present invention superimposes pulsation and vibration on the side of the suspended catalyst solution that is a continuous phase, and bubbles are introduced into the suspended catalyst solution, or the mass transfer rate at the heterogeneous interface is increased. Due to pulsation or the like, the interfacial area due to the dispersion of the suspended catalyst solution is increased to increase the reaction rate with the raw material gas.
[0035]
FIG. 2 is a schematic exaggerated schematic diagram for explaining another reaction tower for reacting a suspended catalyst solution and a raw material gas in the second embodiment of the present invention. In FIG. 2, the reaction tower 11 includes a vibrator 18 that vibrates the suspended catalyst solution, an excitation circuit 181 provided outside the reaction tower 11 that vibrates the vibrator 18, and the reaction tower 11. It differs from the first embodiment in that an eye plate 19 provided slightly below the center is provided.
[0036]
That is, in the second embodiment, the description of the overflow tank 16 is omitted in FIG. When the vibration is a microwave, the excitation circuit 181 is a magnetron or a peripheral circuit thereof. Further, the vibrator 18 shown in FIG. 2 becomes an antenna connected through a waveguide (not shown) in the case of a microwave. Giving microwave vibration to the source gas side excites polar molecules of the source gas and promotes the synthesis reaction.
[0037]
When the vibration is ultrasonic, the vibrator 18 is an ultrasonic vibrator or a horn. Further, the suspended catalyst solution can be agitated by at least one of pulsation, microwave and ultrasonic vibration. Further, in this case, the presence or absence of the eye plate is optional, but the reaction rate can be improved by providing it.
[0038]
The type of the catalyst used in this example is not limited. For example, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, potassium, yttrium, zirconium, niobium, molybdenum, Ruthenium, rhodium, palladium, gold, cadmium, indium, tin, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, silver, mercury, tellurium, lead, bismuth, thallium, uranium, lithium, sodium, potassium, rubidium, Cesium, beryllium, magnesium, calcium, strontium, barium, boron, aluminum, scandium, thorium, lead, lanthanoid copper metals, oxides, and the like can be used.
[0039]
Examples of the solvent used for the catalyst include aliphatic, aromatic, and alicyclic hydrocarbons, alcohols, ethers, ketones, and halogen compounds, and mixtures of these compounds. The solvent may be a light oil from which sulfur has been removed, a vacuum gas oil, a high-boiling fraction of hydrogenated coal tar, or the like.
[0040]
As mentioned above, although the Example of this invention was explained in full detail, this invention is not limited to the said Example. The present invention can be modified in various ways without departing from the scope of the claims. For example, the design and installation of the reaction tower, catalyst, pulsation means, and vibration means can be arbitrarily changed.
[0041]
In the examples of the present invention, only the reaction tower is described, but a publicly known or well-known technique can be used where no other description is given. Similarly, the pulsation means and / or the vibration means can be known or known, and the reaction speed can be increased by changing the low frequency vibration to the high frequency vibration such as microwave.
[0042]
【The invention's effect】
According to the present invention, pulsation or the like is superimposed on the continuous phase of the suspended catalyst solution to promote the foam dispersion of the dispersed phase gas, thereby increasing the interfacial area between the raw material gas and the suspended catalyst solution. The reaction rate could be increased.
[0043]
According to the present invention, the reaction rate can be increased by superimposing pulsation or the like on the continuous phase of the suspended catalyst solution to increase the mass transfer coefficient of the heterophase interface.
[0044]
According to the present invention, in order to increase the interfacial area between the raw material gas and the suspended catalyst solution, the interfacial area is further reduced by superimposing at least one of pulsation, microwave, and ultrasonic vibration. It can be increased to increase the reaction rate.
[Brief description of the drawings]
FIG. 1 is a schematic exaggerated schematic diagram for explaining a reaction tower for reacting a suspended catalyst solution and a raw material gas in the first embodiment of the present invention.
FIG. 2 is a schematic exaggerated schematic diagram for explaining another reaction tower for reacting a suspended catalyst solution and a raw material gas in the second embodiment of the present invention.
FIG. 3 is a view for explaining a dimethyl ether production system in a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 11 ... Reaction tower 12 ... Raw material gas conveyance pipe 13 ... Reactive substance conveyance pipe 131 ... Reactive substance 14 ... Suspended catalyst solution 141 ... Catalyst solution insertion port 142 ... Raw material Gas 15 ... Cooling pipe 151 ... Cooling water 16 ... Overflow tank 161 ... Overflow solution outlet 17 ... Pulsating device 171 ... Cylinder 172 ... Piston 18 ... Vibrator 181 ..Excitation circuit 19 ... eye plate

Claims (6)

In the dimethyl ether production method in which dimethyl ether is produced by directly contacting the source gas and the suspended catalyst solution,
In the reaction tower where the source gas reacts with the suspended catalyst solution, at least one of pulsation, microwave vibration, and ultrasonic vibration is superimposed on the continuous phase of the suspended catalyst solution to promote foam dispersion of the dispersed phase gas. A method for producing dimethyl ether, characterized in that dimethyl ether is produced by increasing the reaction rate by increasing the interface area between the raw material gas and the catalyst solution. In the dimethyl ether production method in which dimethyl ether is produced by directly contacting the source gas and the suspended catalyst solution,
In the reaction tower where the raw material gas reacts with the suspended catalyst solution, the mass transfer coefficient at the heterogeneous interface is increased by superimposing at least one of pulsation, microwave vibration, and ultrasonic vibration on the continuous phase of the suspended catalyst solution. To increase the reaction rate to prepare dimethyl ether. A reaction tower in which the source gas and the suspended catalyst solution are in contact;
A catalyst solution suspension in the reaction tower;
Pulsation generating means for pulsating the continuous phase of the suspended catalyst solution;
A dimethyl ether synthesis reaction apparatus comprising at least A reaction tower in which the source gas and the suspended catalyst solution are in contact;
A catalyst solution suspension in the reaction tower;
Microwave generation means for vibrating the continuous phase of the suspended catalyst solution;
A dimethyl ether synthesis reaction apparatus comprising at least A reaction tower in which the source gas and the suspended catalyst solution are in contact;
A catalyst solution suspension in the reaction tower;
Ultrasonic generating means for applying vibration to the continuous phase of the suspended catalyst solution;
A dimethyl ether synthesis reaction apparatus comprising at least The dimethyl ether synthesis reaction apparatus according to any one of claims 3 to 5, wherein the reaction tower is provided with a countersunk plate in a continuous phase of the suspended catalyst solution.

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