JP2011026578A - Method for producing mixed gas - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a mixed gas, by which a mixed gas for FT synthesis process for producing chemical raw materials such as dimethyl ether, methanol, methane, and alkane, chemical products, and liquid fuel can be produced at low pressure via a single step of coal gasification reaction without using any catalyst and further the production process can be operated for long periods any ashless coal. <P>SOLUTION: The method for producing a mixed gas is a method for producing a mixed gas using non-catalytic gasification reaction of coal, whereby the gasification temperature ranges from 800 to 1,000°C, carbon dioxide and/or water vapor is supplied, and the molar ratio of hydrogen to carbon monoxide (H<SB>2</SB>to CO) in the thus obtained mixed gas is controlled by regulating the volume ratio of water vapor to carbon dioxide (H<SB>2</SB>O to CO<SB>2</SB>). <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a method for producing a mixed gas, and more specifically, a chemical raw material such as methanol, dimethyl ether, methane, and other alkanes from a coal by a gasification reaction in which water vapor and carbon dioxide are supplied in the absence of a catalyst, The present invention relates to a method for producing a raw material for producing liquid fuel in one stage.

  As a process for producing liquid fuel and chemicals from coal, a Fischer-Tropsch synthesis process (hereinafter also referred to as FT synthesis process) has been conventionally performed.

The FT synthesis process is a series of processes for synthesizing liquid hydrocarbons from carbon monoxide and hydrogen using a catalytic reaction, and is the main process currently being performed. The problem with the FT synthesis process is that a raw mixed gas containing carbon monoxide and hydrogen in a fixed ratio must be produced. Specifically, to produce dimethyl ether (DME), the H ₂ / CO ratio in the mixed gas must be 1, and to produce methanol, the ratio must be 2 and methane The ratio must be 3.

However, as long as it is possible to produce a mixed gas whose H ₂ / CO ratio is controlled to a desirable value, chemicals such as methanol, dimethyl ether (DME), methane, and other alkanes and liquid fuels can be efficiently produced by the FT synthesis process. be able to.

The mixed gas used as the raw material of the FT synthesis process can be produced by a coal gasification reaction.
However, in the conventional coal gasification reaction, it is impossible to produce a desirable mixed gas in one stage. That is, since the commercial process of coal gasification requires a temperature of 1200 ° C. or higher, the typical gas composition obtained has a H ₂ / CO ratio of 0.7 and water at 300-400 ° C. The composition had to be adjusted to 1, 2, or 3 by a shift reaction. Therefore, in the production of the mixed gas for the FT synthesis process by the conventional coal gasification reaction, a two-stage process is required, and a large amount of energy must be consumed, so that the low energy efficiency is low. For this reason, there was a problem in commercialization due to poor economic efficiency.

  In order to solve this problem, the present inventors tried a coal gasification reaction at 700 ° C. However, since the reaction rate at 700 ° C. is reduced, the mixed gas cannot be produced at a rate that allows commercialization. This problem of a slow reaction rate can be solved by using a catalyst. For example, Patent Document 1 discloses that hydrogen is produced by a catalytic gasification reaction at 650 ° C.

  However, the method of promoting the gasification reaction using the catalyst has a new problem that the catalyst activity is deactivated due to the interaction between the mineral matter in the coal and the catalyst, making it difficult to recycle and use the catalyst. Occurred. In order to solve this deactivation of the catalytic activity, in Patent Document 1, uncharcoal coal, generally called hypercoal, obtained by deashing raw coal of Pasir subbituminous coal and muria lignite by a solvent extraction method using an organic solvent. It has been proposed to use

  According to the method of Patent Document 1, a long-term operation of a production process in hydrogen production at 650 ° C. is possible, and a catalyst regeneration process can be omitted. However, if a one-stage coal gasification reaction that can be commercialized without using a catalyst can be realized, and if the production process can be operated for a long time without using ashless coal, FT can be performed more efficiently and at low cost. It is possible to produce raw materials for the synthesis process.

JP 2009-13320 A

  In the present invention, a mixed gas for FT synthesis process for producing chemical raw materials such as dimethyl ether, methanol, methane, and other alkanes, chemicals, and liquid fuel is a one-stage coal gasification reaction at low pressure without using a catalyst. It is an object of the present invention to provide a method for producing a mixed gas that can be produced by the above-described method and can be operated for a long time without using ashless coal.

According to this invention, the manufacturing method of the mixed gas shown below is provided.
[1]
A method for producing a mixed gas by a non-catalytic gasification reaction of coal, wherein the gasification temperature is set to 800 to 1000 ° C., carbon dioxide and / or water vapor is supplied, and the volume ratio of water vapor to carbon dioxide (H ₂ O / by controlling the CO ₂ ratio), the production method of the mixed gas and controlling the molar ratio of hydrogen to carbon monoxide in the mixed gas obtained (H 2 _/ CO ratio).
[2]
The method for producing a mixed gas according to claim 1, wherein the noncatalytic gasification reaction is performed under atmospheric pressure.
[3]
The gasification temperature is set within a range of 800 to 1000 ° C., and the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio) is made to correspond to the gasification temperature within a range of 0.3 to 2.5. The mixed gas production method according to claim 1 or 2, wherein the mixed gas for synthesizing dimethyl ether is produced by setting.
[4]
The gasification temperature is set within the range of 800 to 1000 ° C., and the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio) is made to correspond to the gasification temperature within the range of 2.2 to 5.2. The method for producing a mixed gas according to claim 1 or 2, wherein a mixed gas for methanol synthesis is produced by setting.
[5]
The gasification temperature is set within the range of 800 to 1000 ° C., and the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio) is made to correspond to the gasification temperature within the range of 3.8 to 19.3. The method for producing a mixed gas according to claim 1 or 2, wherein a mixed gas for methane synthesis is produced by setting.
[6]
Subbituminous coal or lignite is used. The method for producing a mixed gas according to any one of claims 1 to 5.
[7]
The mixed gas according to any one of claims 1 to 6, wherein coal is supplied into a furnace and brought into contact with water vapor and carbon dioxide, and gas is separated from generated gas and residual coal residue. Production method.
[8]
Using a device in which a Fischer-Tropsch synthesizer is directly connected to a gasification furnace, dimethyl ether, methanol or methane is produced using a mixed gas obtained by the production method according to any one of claims 1 to 7. A method for producing a mixed gas.

In the method for producing a mixed gas of the present invention, steam and carbon dioxide are supplied as gasification agents to coal (raw coal) as non-catalytic, and reacted at 800 to 1000 ° C., thereby allowing commercialization at low energy. A mixed gas can be produced at a possible rate. Further, the molar ratio of hydrogen to carbon monoxide (H ₂ / CO ratio) in the mixed gas obtained by controlling the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio) can be controlled. . By this method, the H ₂ / CO ratio can be made close to 1, close to 2, close to 3 in a one-stage catalytic gasification reaction at a low pressure of 800 to 1000 ° C., so that mixing for producing dimethyl ether, methanol, and methane is possible. The gas can be obtained in a one-stage gasification reaction process.
In the present invention, gasification can be carried out at a reaction rate at which commercialization is possible without using a catalyst, so that there is no problem of deactivation of the catalyst, and long continuous operation is easy. Moreover, since coal (raw coal) is used as it is, gasification at a low cost is possible.
Furthermore, by combining these effects, the production of dimethyl ether, methanol, and methane by the FT synthesis reaction can be continuously produced with one apparatus.

FIG. 1 (a) shows an H ₂ O / CO ₂ ratio (volume ratio) = 100/0, 85/15, 70/30 in a non-catalytic gasification reaction using raw coal at a gasification temperature of 900 ° C. , 50/50, and 0/100 are graphs showing the conversion rate (vertical axis) with respect to the gasification time (horizontal axis). FIG.1 (b) is a graph which shows the composition of the gas obtained in the reaction shown to Fig.1 (a). FIG. 2 (a) shows the H ₂ O / CO ₂ ratio (volume ratio) = 100/0, 70/30, and 0/100 in a non-catalytic gasification reaction using raw coal at 800 ° C. It is a graph which shows the conversion rate (vertical axis) with respect to gasification time (horizontal axis) in the case. FIG. 2B is a graph showing the composition of the gas obtained in the reaction shown in FIG. FIG. 3 (a) shows the H ₂ O / CO ₂ ratio (volume ratio) = 100/0, 70/30, and 0/100 in a non-catalytic gasification reaction using raw coal at 1000 ° C. It is a graph which shows the conversion rate (vertical axis) with respect to gasification time (horizontal axis) in the case. FIG. 3B is a graph showing the composition of the gas obtained in the reaction shown in FIG. FIG. 4 (a) shows the H ₂ O / CO ₂ ratio (volume ratio) = 100/0, 50/50, and 0/100 in a non-catalytic gasification reaction using raw coal at 700 ° C. It is a graph which shows the conversion rate (vertical axis) with respect to gasification time (horizontal axis) in the case. FIG. 4B is a graph showing the composition of the gas obtained in the reaction shown in FIG. FIG. 5 is a graph showing the obtained gas composition (vertical axis) relative to the H ₂ O / CO ₂ ratio (horizontal axis) in a non-catalytic gasification reaction using raw coal at 900 ° C. FIG. 6A is a graph showing the composition (vertical axis) of the obtained gas with respect to the H ₂ O / CO ₂ ratio (horizontal axis) in a non-catalytic gasification reaction using raw coal at 800 ° C. . FIG. 6B is a graph showing the composition (vertical axis) of the obtained gas with respect to the H ₂ O / CO ₂ ratio (horizontal axis) in a non-catalytic gasification reaction using raw coal at 1000 ° C. . FIG. 7 is a graph showing the composition (vertical axis) of the obtained gas with respect to the H ₂ O / CO ₂ ratio (horizontal axis) in a non-catalytic gasification reaction using raw coal at 700 ° C. FIG. 8 is a drawing showing an example of an apparatus used in the method for producing a mixed gas and dimethyl ether, methanol, and methane of the present invention.

Hereinafter, the manufacturing method of the mixed gas of this invention is demonstrated in detail.
In the method for producing a mixed gas by the gasification reaction of the present invention, the gasification temperature is set to 800 to 1000 ° C., a gasifying agent composed of water vapor and / or carbon dioxide is supplied, and coal (raw coal) is used without catalyst. The gasification reaction is performed. Furthermore, in the present invention, as will be described later, the molar ratio of hydrogen to carbon monoxide (H ₂ / CO ratio) is controlled by controlling the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio). Is done.
If steam is not supplied, only thermal decomposition proceeds, and as a result, a large amount of char (coal residue), tar, and gas are generated, and a mixed gas for producing dimethyl ether, methanol, and methane cannot be obtained.

  The gasification temperature in this invention is 800-1000 degreeC, Preferably it is more than 800 degreeC and 1000 degrees C or less, More preferably, it is 850-1000 degreeC, More preferably, it is 850-950 degreeC. Within this temperature range, gasification occurs at a commercially viable rate without using a catalyst. Therefore, continuous operation for a long time can be easily performed. If the gasification temperature is too low, a commercially viable reaction rate cannot be secured unless a catalyst is used. As a result, if ashless coal is not used, continuous operation for a long time cannot be performed, which may lead to an increase in cost. On the other hand, if the gasification temperature is too high, a large amount of energy must be consumed, and the production efficiency may deteriorate, leading to an increase in cost.

In FIG. 1 (a), H ₂ O / CO ₂ ratio (volume ratio) is 100/0, 85/15, 70/30, 50/50 under conditions of gasification temperature of 900 ° C. and no catalyst for raw coal. The result of having measured the gasification reaction when changing to 0/100 is shown. The horizontal axis is the gasification time, and the vertical axis is the conversion rate. FIG. 1B shows the composition of the obtained mixed gas (number of moles of component gas obtained from the unit weight of raw coal) in each of the above cases.
Further, in FIG. 2 (a), for the raw coal, the H ₂ O / CO ₂ ratio (volume ratio) is changed to 100/0, 70/30, and 0/100 under conditions of a gasification temperature of 800 ° C. and no catalyst. The result of having measured the gasification reaction in the case where it was made to show is shown. FIG. 2B shows the composition of the obtained mixed gas in each of the above cases. The horizontal axis represents the H ₂ O / CO ₂ ratio of the supplied gasifying agent, and the vertical axis represents the composition of the obtained mixed gas (number of moles of component gas obtained from per unit raw coal).
Further, in FIG. 3 (a), the H ₂ O / CO ₂ ratio (volume ratio) is changed to 100/0, 70/30, and 0/100 for the raw coal under a gasification temperature of 1000 ° C. and no catalyst. The result of having measured the gasification reaction in the case where it was made to show is shown. In addition, in FIG.3 (b), the composition of the obtained mixed gas in each of the above-mentioned cases is shown (number of moles of component gas obtained from per unit weight of raw coal).
From FIG. 1 (a), FIG. 2 (a), and FIG. 3 (a), by supplying steam and / or carbon dioxide to the raw coal, it is 800 to 1000 ° C., preferably 850 to 1000 ° C., more preferably 850. It can be seen that a mixed gas of carbon monoxide and hydrogen can be obtained at a speed that can be industrialized in a temperature range of ˜950 ° C.

Further, in FIG. 4 (a), the H ₂ O / CO ₂ ratio (volume ratio) of raw coal is changed to 100/0, 50/50, and 0/100 under a gasification temperature of 700 ° C. and no catalyst. The result of having measured the gasification reaction in the case where it was made to show is shown. FIG. 4B shows the composition of the obtained mixed gas in each of the above cases.
FIG. 4A shows that 700 ° C. is not suitable for commercialization because the gasification rate is slow at 700 ° C. regardless of the H ₂ O / CO ₂ ratio.

  In addition, although the mixed gas obtained may contain carbon dioxide, it is a part of the carbon dioxide used as a gasifying agent, and is not the carbon dioxide produced | generated by gasification of the coal which is a raw material.

Means for maintaining the gasification temperature at 700 to 1000 ° C. is appropriately selected in consideration of a reaction system such as a batch system or a continuous system. For example, an external heat source such as combustion heat of by-product coal (extraction residue) It is preferable to employ the heating method according to the above.
Moreover, there is no restriction | limiting in particular in temperature rising rate, For example, it is 20-1000 degreeC / min, For example, 1-120 minutes are preferable and, as for reaction time, 30-60 minutes are still more preferable.

The gasification reaction of the present invention is preferably performed under atmospheric pressure. However, it is also possible to apply a pressure that does not impair the object of the present invention. In that case, since manufacture of a manufacturing apparatus is easy, 10 atmospheres or less are preferable, and 5 atmospheres or less, 3 atmospheres or less, 2 atmospheres or less, and 1.5 atmospheres or less are more preferable in order.
However, the atmospheric pressure in the present invention means that the gas generated from coal is pressurized by abrupt expansion inside the apparatus without intentional pressurization.

In the present invention, the molar ratio of hydrogen to carbon monoxide (H ₂ / CO ratio) in the mixed gas obtained is controlled by changing the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio). It can be performed. That is, as shown in FIGS. 1 (b), 2 (b), and 3 (b), it is obtained when the H ₂ O / CO ₂ ratio becomes small at a gasification temperature of 800 to 1000 ° C. There is a tendency that the hydrogen content in the mixed gas decreases and the H ₂ / CO ratio decreases. For example, at 900 ° C., when the water vapor / carbon dioxide ratio = 100/0, the hydrogen content is maximum, and when the water vapor amount is reduced to 70/30, 60/40, 50/50, 30/70, it can be obtained. The proportion of hydrogen in the mixed gas is reduced and carbon monoxide is increased. When the water vapor / carbon dioxide ratio = 0/100, most of the product gas is carbon monoxide, and the H ₂ / CO ratio is close to zero.

By utilizing this characteristic, the hydrogen / carbon monoxide molar ratio in the produced mixed gas is controlled by changing the water vapor / carbon dioxide volume ratio (H ₂ O / CO ₂ ratio) in the gasifying agent (H ₂ / CO ratio).

FIG. 5 shows the relationship between the H ₂ O / CO ₂ ratio (horizontal axis) of water vapor and carbon dioxide supplied to coal at a gasification temperature of 900 ° C. and the H ₂ / CO ratio (vertical axis) of the resulting mixed gas. Show. FIG. 5 is a graph created based on FIG. The molar ratio of hydrogen to carbon monoxide in the mixed gas obtained at a gasification temperature of 900 ° C. by changing the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio) supplied to the raw coal from FIG. It can be seen that the ratio (H ₂ / CO ratio) can be controlled.

Further, in FIG. 6 (a), the gas temperature 800 ° C., steam is supplied to the raw coal and _{H 2} O / CO 2 ratio of carbon dioxide (horizontal axis), _H 2 / CO ratio of the mixed gas obtained ( The vertical axis). FIG. 6A is a graph created based on FIG. From FIG. 6 (a), even at 800 ° _C., varying the H ₂ O / CO 2 ratio from 100/0 to 70/30, _H 2 / CO ratio in the resulting gas from 12.6 2.1 When the ratio is changed to 0/100, the H ₂ / CO ratio becomes 0.1. Therefore, by changing the H ₂ O / CO ₂ ratio, hydrogen to carbon monoxide in the obtained mixed gas It can be seen that the molar ratio (H ₂ / CO ratio) can be controlled.

FIG. 6B shows the H ₂ O / CO ₂ ratio (horizontal axis) of water vapor and carbon dioxide supplied to the raw coal at a gasification temperature of 1000 ° C., and the H ₂ / CO ratio ( The vertical axis). FIG. 6B is a graph created based on FIG. From FIG. 6 (b), even at 1000 ° C., when the H ₂ O / CO ₂ ratio is changed from 100/0 to 70/30, the H ₂ / CO ratio in the obtained gas is changed from 3.3 to 1.7. When the ratio is changed to 0/100, the H ₂ / CO ratio becomes 0.04. By changing the H ₂ O / CO ₂ ratio, the hydrogen to carbon monoxide in the obtained mixed gas It can be seen that the molar ratio (H ₂ / CO ratio) can be controlled.

Even in the reaction at 700 ° C., as shown in FIG. 7, when the H ₂ O / CO ₂ ratio is decreased, the hydrogen content in the obtained mixed gas is decreased and the H ₂ / CO ratio is decreased. Tend. FIG. 7 is a graph created based on FIG.

  By utilizing the above relationship, in a non-catalytic reaction of raw coal at 800 to 1000 ° C., a mixed gas for dimethyl ether synthesis, a mixed gas for methanol synthesis, and a mixed gas for methane synthesis can be produced industrially. it can.

Table 1 shows a range of H ₂ O / CO ₂ ratios suitable for synthesizing dimethyl ether, methanol, and methane at gasification temperatures of 800 ° C., 900 ° C., and 1000 ° C., respectively. By utilizing the relationship shown in Table 1, a mixed gas for synthesizing dimethyl ether, a mixed gas for synthesizing methanol, and a mixed gas for synthesizing methane can be created separately at a gasification temperature of 800 to 1000 ° C.

Specifically, the gasification temperature is set within a range of 800 to 1000 ° C., and the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio) is set within a range of 0.3 to 2.5. By setting the temperature corresponding to the crystallization temperature, a mixed gas for synthesizing dimethyl ether having a molar ratio of hydrogen to carbon monoxide (H ₂ / CO ratio) in the vicinity of 1 can be produced.

In addition, the gasification temperature is set within a range of 800 to 1000 ° C., and the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio) is set to the gasification temperature within a range of 2.2 to 5.2. By setting them in correspondence, it is possible to produce a mixed gas for synthesizing methanol in which the molar ratio of hydrogen to carbon monoxide (H ₂ / CO ratio) is around 2.

Further, the gasification temperature is set within a range of 800 to 1000 ° C., and the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio) is set within the range of 3.8 to 19.3. By setting it correspondingly, it is possible to produce a mixed gas for methane synthesis in which the molar ratio of hydrogen to carbon monoxide (H ₂ / CO ratio) is around 3.

  In the mixed gas production method of the present invention, as described above, gasification is performed at 800 to 1000 ° C. without using a catalyst. Therefore, even if raw coal is used, the problem of deactivation of the catalyst does not occur. Therefore, it is possible to continuously produce a mixed gas by direct gasification reaction of raw coal for a long time. Furthermore, since it is not necessary to use ashless coal, the manufacturing cost can be reduced by omitting the process of deashing raw coal by the solvent extraction method.

In the present invention, it is preferable to use subbituminous coal or lignite as raw coal.
Here, subbituminous coal generally means low-grade coal having a composition comprising combustible content: 55-80% and moisture: 15-45%. Examples of such sub-bituminous coal include Pasir coal, Wyoming coal, Gunung Bayan coal, MTBU coal, Kitadine coal, Binungan coal, Wyodak coal, Ronkou coal, K-Prima coal, Tanitoharum coal, Marinau coal, and Pacific coal. The

  Moreover, lignite generally means low-grade coal having a composition comprising combustible content: 35 to 55% and moisture content: 45 to 65%. Examples of such lignite include mulia coal, roy young coal, bureau zap charcoal, yaroon charcoal, adaro charcoal, and bellau charcoal.

  As a method of continuously gasifying reaction while supplying steam and carbon dioxide (gasification agent) to coal, raw coal is supplied into a fluidized bed gasification furnace, and steam and carbon dioxide (gasification agent) Preferred is a method in which coal is burned while well contacting raw coal, water vapor, and carbon dioxide while supplying hot air, and the gas is separated from the generated gas and the remaining coal residue. By supplying steam, carbon dioxide, and hot air, the raw coal can be finely divided into a fluidized state (water vapor, carbon dioxide, and hot air also act as a fluidizing agent) and gasification can be performed efficiently. Gasification reaction can occur. Furthermore, by changing the steam / carbon dioxide ratio supplied to the gasification furnace, a synthesis gas having a desirable hydrogen / carbon monoxide ratio can be produced in one stage of gasification.

  An example of an apparatus used for such a reaction is shown in FIG. In the apparatus shown in FIG. 8, since the carbon dioxide produced by the gasification process is recovered, supplied to the steam / carbon dioxide mixer 6 and reused, the carbon dioxide production process is unnecessary. The heat necessary for gasification of the gasifying agent is supplied by moving a high-temperature fluid medium from the boiler 2 (combustion furnace) to the gasification furnace 3.

In FIG. 8, 1 is a feeder, 2 is a boiler, 3 is a gasifier, 4 is a medium recovery unit, 5 is a heat exchanger, 6 is a steam / carbon dioxide mixer, and 7 is a generated gas cleaner. 8 is a compressor, 9 is an FT synthesizer, and 10 is an exhaust gas discharger.

  In the present invention, as shown in an example in FIG. 8, from a mixed gas obtained by the catalytic gasification reaction using a device in which a Fischer-Tropsch (FT) synthesizer is directly connected to a gasification furnace via a compressor. It is preferable to produce dimethyl ether, methanol, or methane. If it does in this way, since FT reaction is immediately performed using the mixed gas obtained by the gasification reaction of one step, dimethyl ether, methanol, and methane can be manufactured efficiently. Since carbon dioxide is recovered as a by-product in the final product of FT synthesis, it is mixed with water vapor and recycled as a gasifying agent in a gasification furnace. Carbon dioxide can also act as a fluidizing agent in the case of a fluidized bed gasifier.

  Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to the examples.

Examples 1-5
Under atmospheric pressure, steam / carbon dioxide is supplied to subbituminous coal (carbon 72%), and H ₂ O / CO ₂ ratio (volume ratio) is 100/0, 85/15, 70/30, 50/50, 0 The gasification test using a thermogravimetric analyzer (TGA) was performed at 900 ° C. The results are shown in FIGS. 1 (a) and 1 (b).

Comparative Examples 1-3
Under atmospheric pressure, steam / carbon dioxide is supplied to subbituminous coal (carbon 72%) to change the H ₂ O / CO ₂ ratio (volume ratio) to 100/0, 50/50, 0/100, and heat. A gasification test using a gravimetric analyzer (TGA) was performed at 700 ° C. The results are shown in FIGS. 4 (a) and 4 (b).

From the comparison between FIG. 1 (a) and FIG. 4 (a), 900 ° C. is a temperature at which the gasification reaction occurs at a rate at which commercialization is possible regardless of the H ₂ O / CO ₂ ratio, whereas 700 ° C. Since the gasification rate is low, it can be seen that the reaction temperature is not suitable for commercialization.

  From FIG. 1 (b), when the water vapor / carbon dioxide ratio = 100/0, the product gas is almost hydrogen, and as the ratio becomes 85/15, 70/30, 50/50, the hydrogen decreases, It can be seen that when carbon monoxide increases and the water vapor / carbon dioxide ratio = 0/100, almost all carbon monoxide is obtained.

  FIG. 5 is a graph showing the change in the hydrogen / carbon monoxide ratio in the product gas with respect to the change in the water vapor / carbon dioxide ratio, which is a gasifying agent, based on the result of FIG. FIG. 5 shows that in the gasification reaction at 900 ° C., when the water vapor / carbon dioxide ratio = 100/0, 5/15, 70/30, 50/50, 0/100, the hydrogen / carbon monoxide molar ratio is 4. .2, 2.2, 1.6, 0.9, 0.1. From this result, it can be seen that the hydrogen / carbon monoxide ratio of the product gas can be controlled by changing the water vapor / carbon dioxide ratio as the gasifying agent. That is, it is shown that the hydrogen / carbon monoxide molar ratio of the product gas can be controlled to 1 to 4 in a one-stage gasification process by changing the water vapor / carbon dioxide ratio as a gasifying agent. When the hydrogen / carbon monoxide ratio is 1, 2 and 3, they can be used as synthesis gas for producing DME, methanol, methane and other chemicals, respectively.

Examples 6-8
Using subbituminous coal (carbon 72%) used in Example 1, the H ₂ O / CO ₂ ratio was 100/0, 70/30, 0/100 under atmospheric pressure, and the reaction temperature was set to 800 ° C. Others performed the gasification test using TGA similarly to Examples 1-3. The results are shown in FIGS. 2 (a), 2 (b) and 6 (a).

  From FIG. 2 (a), the gasification reaction of coal occurs at a rate at which commercialization is possible even at 800 ° C., and by changing the water vapor / carbon dioxide ratio of the gasifying agent even at 800 ° C. from FIG. 6 (a). It can be seen that the product gas hydrogen / carbon monoxide ratio can be controlled.

Examples 9-11
Using subbituminous coal (carbon 72%) used in Example 1, the H ₂ O / CO ₂ ratio was set to 100/0, 70/30, 0/100 under atmospheric pressure, and the reaction temperature was set to 1000 ° C. Others performed the gasification test using TGA similarly to Examples 1-3. The results are shown in FIGS. 3 (a), 3 (b) and 6 (b).

  From Fig. 3 (a), the coal gasification reaction occurs at a controllable rate that can be commercialized even at 1000 ° C. From Fig. 6 (b), the steam / carbon dioxide ratio of the gasifying agent also changes at 1000 ° C. It can be seen that the product gas hydrogen / carbon monoxide ratio can be controlled.

Claims (8)

A method for producing a mixed gas by a non-catalytic gasification reaction of coal, wherein the gasification temperature is set to 800 to 1000 ° C., carbon dioxide and / or water vapor is supplied, and the volume ratio of water vapor to carbon dioxide (H ₂ O / by controlling the CO ₂ ratio), the production method of the mixed gas and controlling the molar ratio of hydrogen to carbon monoxide in the mixed gas obtained (H 2 _/ CO ratio).   The method for producing a mixed gas according to claim 1, wherein the noncatalytic gasification reaction is performed under atmospheric pressure. The gasification temperature is set within a range of 800 to 1000 ° C., and the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio) is made to correspond to the gasification temperature within a range of 0.3 to 2.5. The mixed gas production method according to claim 1 or 2, wherein the mixed gas for synthesizing dimethyl ether is produced by setting. The gasification temperature is set within the range of 800 to 1000 ° C., and the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio) is made to correspond to the gasification temperature within the range of 2.2 to 5.2. The method for producing a mixed gas according to claim 1 or 2, wherein a mixed gas for methanol synthesis is produced by setting. The gasification temperature is set within the range of 800 to 1000 ° C., and the volume ratio of water vapor to carbon dioxide (H ₂ O / CO ₂ ratio) is made to correspond to the gasification temperature within the range of 3.8 to 19.3. The method for producing a mixed gas according to claim 1 or 2, wherein a mixed gas for methane synthesis is produced by setting.   Subbituminous coal or lignite is used. The method for producing a mixed gas according to any one of claims 1 to 5.   The mixed gas according to any one of claims 1 to 6, wherein coal is supplied into a furnace and brought into contact with water vapor and carbon dioxide to separate the gas from the generated gas and the remaining coal residue. Production method.   Using a device in which a Fischer-Tropsch synthesizer is directly connected to a gasification furnace, dimethyl ether, methanol or methane is produced using a mixed gas obtained by the production method according to any one of claims 1 to 7. A method for producing a mixed gas.