JPH0953083A - Medium pressure, continuous gasification apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gasification apparatus which has a simple construction and can efficiently conduct gasification at a low cost by adopting a reaction pipe having a double structure of an outer pipe in a substantially cylindrical hollow form and an inner pipe in a substantially cylindrical form provided coaxially within the outer pipe. SOLUTION: A raw material 1a of a medium-pressure liquid in a raw material tank 1 is gasified and suitably mixed with a recycled gas 1b, the mixture is heated, and an unsaturated hydrocarbon is converted in a desulfurizer 8 to a saturated hydrocarbon, thereby conducting desulfurization. Steam 1e produced in a boiler 47 is suitably mixed therewith, and the mixture is then allowed to flow into a reforming chamber 33 provided on the peripheral side of a reaction pipe 15 having a double pipe structure in a reaction column 10 to reform, for example, butane 1a, and then allowed to flow into a methanation chamber 34 provided on the internal circumference side of the reaction pipe 15 to conduct methanation. Methanation is again conducted in a methane synthesis column 40, followed by cooling and separation and removal of residual water vapor. Thereafter, the residue is separated in an absorption separation column 44 into a gas mixture 1j composed mainly of methane and an off-gas 1k. The gas mixture 1j composed mainly of methane is mixed with a part of the raw material 1a to a predetermined calorific value to prepare a gas 1l. Thus, the thermal efficiency is improved in a simple construction, and gasification is conducted at a low cost.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to butane (C
_{The present} invention relates to a medium-pressure continuous gasifier which desulfurizes raw materials such as ₄ H ₁₀ ) and naphtha and then reforms them into a gas containing methane as a main component with a nickel-based catalyst by mixing with steam.

[0002]

2. Description of the Related Art Conventionally, as an intermediate pressure continuous gasifier for producing an intermediate pressure gas having a calorific value of around 4500 kcal / Nm ³ from a raw material such as butane (C ₄ H ₁₀ ) and naphtha, for example, FIG.
ICI (Imperial), which consists of four divisions: desulfurization, reforming, carbon monoxide conversion (CO conversion), and heat recovery
Chemical Industries) formula is known.

The ICI type medium-pressure continuous gasifier shown in FIG. 3 uses a raw material 61a pressurized to about 10 kgf / cm ³ and a recycled gas 61b, which is a part of the produced gas, for hydrogenation. Mix as a source and heat to about 350 ° C. in heater 62.
Then, the heated gas 61d flows into the desulfurizer 64 filled with the zinc oxide (ZnO) -based adsorbent 63a and adsorbs and removes hydrogen sulfide (H ₂ S) in the raw material 61a. Furthermore, a cobalt-molybdenum (Co-Mo) -based hydrogenation catalyst (COMO
X) 65a flows into the desulfurizer 66 filled on the upstream side, and the hydrogen (H ₂ ) of the recycle gas 61b causes the organic sulfur compound in the raw material 61a to be saturated hydrocarbon (C _n H _{2n + 2} ) and H ₂ S.
Reacting with the above, hydrogen sulfide is adsorbed and removed by the ZnO-based adsorbent 63a on the downstream side of the desulfurizer 66, and the raw material 61a is desulfurized.

Next, the desulfurized raw material 61a is mixed with heated steam (H ₂ O) 61c at a predetermined ratio to obtain nickel (N 2
i) It flows into the reaction tube 68 filled with the system reforming catalyst 67a.
Since the steam reforming reaction by the nickel-based reforming catalyst 67a is a large endothermic reaction, the outside of the reaction tube 68 is
The naphtha and butane of the raw material 61a are heated by a burner (not shown) which uses a part of the butane as fuel.

The raw material 61a flowing into the reaction tube 68 is
C _n H _{2n + 2} reacts with carbon monoxide (CO) and hydrogen (H ₂ ) with H ₂ O, and the generated carbon monoxide (CO), in the raw material 61a and in the recycle gas 61b. Carbon monoxide (CO) and carbon dioxide (CO ₂ )
It reacts with methane (CH ₄ ) and carbon dioxide (CO ₂ ) with hydrogen (H ₂ ) and H ₂ O of steam 61 c. The amount of these reactions produced is determined by the temperature, pressure, steam ratio, and the like. Then, methane (CH ₄₎ mainly composed of hydrogen (H _2), carbon dioxide (CO _2), and is reformed into a gas 61e having a predetermined composition containing carbon monoxide (CO).

After this, the reformed gas 61e is cooled to about 350 ° C. in the waste heat boiler 69, and iron-chromium (Fe-C)
r) The catalyst 70a flows into the CO shift converter 71, and the Fe-Cr catalyst 70a causes carbon monoxide (CO) in the gas 61e to remain in the carbon dioxide (H ₂ O) 61c. It reacts with CO ₂ ) and hydrogen (H ₂ ) to reduce carbon monoxide (CO).

Then, the modified gas 61f is separated into steam and water, diluted with air, and the gas 61f becomes about 4500 kcal / Nm ^3.
61 g of the supply gas is manufactured by adjusting the heat generation amount of the above, cooled by the cooler 72, depressurized to about 7 kgf / cm ² by the pressure adjusting valve 73, and stored in the storage tank.

[0008]

However, in the above-mentioned conventional medium-pressure continuous gasifier, the raw material 61a is once produced by pressurizing it to a high pressure, and the gas is depressurized to supply 61 g of gas. There is a problem of reduced efficiency.

Further, in order to efficiently and surely carry out the catalytic reaction according to the purpose, it is necessary to heat the raw material 61a to a predetermined temperature range. Therefore, various catalysts 63a, 65a, 67a,
It is necessary to provide a plurality of equipments such as desulfurizers 64, 66 and reaction tubes 68 each filled with 70a, and the apparatus becomes large in size, and the equipment structure such as heating means such as burner and heat recovery means (not shown) is also provided. There is a problem that the device becomes complicated and the device becomes large.

On the other hand, carbon monoxide (CO) is replaced with hydrogen (H ₂ )
The methanation reaction in which methane (CH ₄ ) and carbon dioxide (CO ₂ ) are reacted with methane and steam (H ₂ O) is an exothermic reaction, and saturated hydrocarbon (C _n H _{2n + 2} ) is converted into steam (H ₂ O) with carbon monoxide (CO) and hydrogen (H
_The steam reforming reaction that reacts with ₂ ) is an endothermic reaction.
Then, the methanation reaction proceeds in a temperature range slightly lower than the steam reforming reaction. However, since the methanation reaction and the steam reforming reaction are performed in parallel in the reaction tube for reforming, there is a problem that the thermal efficiency of heating the reaction tube by the burner is reduced and the reaction efficiency is reduced. .

The present invention has been made in view of the above problems of the prior art, and an object of the present invention is to provide a medium-pressure continuous gasifier capable of efficiently and inexpensively gasifying with a simple structure.

[0012]

A medium-pressure continuous gasifier according to the present invention is provided with an inflow port into which a raw material mixed with steam after desulfurization flows, and a hydrogen, carbon dioxide and A reforming chamber having a nickel-based reforming catalyst that reacts with a mixed gas containing methane as a main component, and a carbon dioxide gas and hydrogen of the mixed gas flowing from the reforming chamber and communicating with the reforming chamber to react with methane A reforming chamber provided with a methanation chamber having a nickel-based methanation catalyst and an outlet for communicating a gas mainly containing methane from the methanation chamber. A double pipe structure in which the methanation chamber is arranged on the central axis substantially coaxially is used, and the raw material mixed with steam after desulfurization is hydrogen, carbon dioxide and methane with a nickel-based reforming catalyst. The methanation chamber, which communicates with the reforming chamber and causes the carbon dioxide gas and hydrogen of the nickel-based methanation catalyst mixed gas to exothermically react with methane, is formed on the central axis of the reforming chamber that causes an endothermic reaction with the mixed gas containing the main component Since it is coaxially arranged and formed into a double pipe structure, the heat due to the exothermic reaction of the methanation chamber is efficiently transferred to the reforming chamber with a simple configuration in which the methanation and steam reforming are performed by one device. The amount of heat supplied from the outside necessary for the endothermic reaction in the reforming chamber is reduced, and gasification becomes inexpensive.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of a medium-pressure continuous gasifier according to the present invention will be described below with reference to the drawings.

In FIG. 1, reference numeral 1 denotes a raw material tank. In the raw material tank 1, a raw material 1a such as butane (C ₄ H ₁₀ ) or naphtha is stored in a liquid state at a medium pressure of, for example, about 7 kgf / cm ^2. Has been done. The raw material tank 1 is connected to a raw material evaporator 4 having a double pipe structure in which an inner pipe 3 in which a liquid raw material is circulated is connected. The inner pipe 3 of the raw material evaporator 4 is connected to a liquid raw material. Is passed and vaporized.

Further, a first raw material mixer 5 is connected to the inner pipe 3 of the raw material evaporator 4, and the first raw material mixer 5 is connected.
Is mixed with the vaporized raw material at a predetermined ratio with a recycled gas 1b serving as a hydrogen source for hydrogenation, which is a part of a by-product gas being produced. Further, the first raw material mixer 5 is provided with an inner pipe 6 through which the vaporized raw material 1a flows, and a mixed gas 1c of the raw material 1a and the recycled gas 1b is kept at a predetermined temperature, for example, about 350 ° C.
A raw material heater 7 having a double tube structure for heating is connected.

A desulfurizer 8 is connected to the inner pipe 6 of the raw material heater 7. In the desulfurizer 8, a first desulfurization chamber 8a, a second desulfurization chamber 8b, and a third desulfurization chamber 8c are sectioned from the lower end in the axial direction. In addition, the first desulfurization chamber 8a
Is filled with a nickel-molybdenum (Ni-Mo) -based hydrogenation catalyst, and the second desulfurization chamber 8c is filled with a cobalt-molybdenum (Co-Mo) -based hydrogenation catalyst (COMOX). The unsaturated hydrocarbon in the raw material 1a is reacted with hydrogen (H ₂ ) in the recycled gas 1b into a saturated hydrocarbon (C _n H _{2n + 2} ) by the addition catalyst, and the organic sulfur compound in the raw material 1a is saturated hydrocarbon ( C _n H _{2n + 2} ) and hydrogen sulfide (H ₂ S). Then, the third desulfurization chamber 8c is filled with a zinc oxide (ZnO) -based adsorbent that adsorbs and removes hydrogen sulfide (H ₂ S) in the mixed gas 1c.

Further, the desulfurizer 8 has a second raw material mixer 9
Is connected, and the mixed gas 1d desulfurized by the desulfurizer 8 is mixed with water vapor (H ₂ O) 1e adjusted in a separate step at a predetermined ratio. A reaction tower 10 as a medium pressure continuous gasifier is connected to the second raw material mixer 9. As shown in FIGS. 1 and 2, this reaction tower 10 has refractory material on its inner wall.
It is composed of a hollow kiln 14 provided with a heating chamber 13 in which 12 is provided, and a reaction tube 15 arranged in the heating chamber 13 inside the kiln 14.

Further, the kiln body 14 is formed in a substantially cylindrical shape, and is arranged along the vertical direction of the axial direction of the heating chamber 13 formed inside. Further, a kiln port 17 is provided at the outer peripheral edge of the lower end of the kiln body 14, and an exhaust port 18 is provided at the outer peripheral edge of the upper end. Furthermore, an annular fixing means 20 is provided at the upper end of the kiln body 14 and opens around a mounting port into which the reaction tube 15 is fitted and fixed.

On the other hand, the reaction tube 15 has a substantially cylindrical shape, and is composed of an outer tubular body 22 having a substantially cylindrical hollow shape and an inner tubular body 23 having a substantially cylindrical shape coaxially disposed in the outer tubular body 22. It is formed in a heavy pipe structure. An annular flange 24 is provided at the upper end of the outer tube body 22 for inserting and fixing the upper portion of the inner tube body 23, and a flow of the raw material 1a from the second raw material mixer 9 flowing into the flange portion 24. The entrance 25 is formed as an opening. Further, a mesh plate-shaped support plate 28 having a plurality of vent holes 27 formed therein is provided in the lower part of the outer tube body 22, and below the support plate 28, granular bodies 29 such as gravel and ceramics are provided. The catalyst support portion 30 is formed so as to be housed therein.

The inner pipe 23 has a lower end placed and fixed on a support plate 28, an upper end drawn upward from the upper part of the outer pipe 22, and an outer peripheral surface of the upper part fixed to the flange 24. It is provided coaxially within the body 22. Further, at the upper end of the inner pipe body 23,
An outlet 31 is formed so as to flow out 1 g of the mixed gas in 23.

Between the outer tube body 22 and the inner tube body 23,
A reforming chamber 33 is formed by being filled with a nickel-based reforming catalyst. In the reforming chamber 33, the mixed gas introduced from the inflow port 25 reacts with a mixed gas of hydrogen (H ₂ ), carbon monoxide (CO), carbon dioxide (CO ₂ ) and methane (CH ₄ ),
That is, the reactions shown in Chemical formulas 1 to 5 have occurred.

[0022]

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Embedded image Then, butane (C _m which is a raw material shown in Chemical formula 1 and Chemical formula 2)
The decomposition reaction of H _n ) is an endothermic reaction, the methanation reaction shown in Chemical formulas 3 and 4 and the shift reaction shown in Chemical formula 5 are exothermic reactions, and the endothermic reaction shown in Chemical formula 1 to Chemical formula 5 is as a whole.

On the other hand, a methanation chamber 34 is formed in the inner tube 23 by being filled with a nickel-based methanation catalyst. The methanation chamber 34 contains hydrogen (H ₂ ) and carbon monoxide (C) flowing from the reforming chamber 33 through the catalyst supporting portion 30.
O), carbon dioxide (CO ₂ ), carbon monoxide (CO) 1f mixed gas reformed into methane (CH ₄ ) and carbon dioxide (CO ₂ ) and hydrogen (H ₂ ) to produce methane (CH ₄₎ ) Is generated, that is, the reactions shown in Chemical formulas 4 and 6 occur.

[0024]

[Chemical 6] The reactions shown in Chemical formulas 4 and 6 generate heat by exothermic reactions, and the generated heat generated in the methanation chamber 34 is transferred to the reforming chamber 33 located on the outer peripheral side for heat exchange.

Further, between the outer tube body 22 and the inner tube body 23,
Similar to the inner pipe body 23, the lower end is placed and fixed on the support plate 28 while penetrating the reforming chamber 33 and substantially parallel to the inner pipe body 23, and the upper end is led out upward from the upper part of the outer pipe body 22. A gas outflow pipe 35 is provided so that a part of the mixed gas 1f flowing through the reforming chamber 33 can be extracted. As shown in FIG. 1, the recycled gas outflow pipe 35 is connected to a recycled gas vapor-liquid separator 38 via a recycled gas cooler 37 for cooling the recycled gas 1b. This recycled gas vapor-liquid separator 38 is a liquefied unreacted water vapor (H) in the recycled gas 1b cooled by the recycled gas cooler 37.
₂ O) is separated off. Further, a recycled gas compressor 39 is connected to the recycled gas vapor-liquid separator 38, and this recycled gas compressor 39 is connected to the first raw material mixer 5 to pressurize the vaporized raw material 1a to a predetermined pressure. The recycled gas 1b thus prepared is mixed at a predetermined ratio.

The outlet 31 of the reaction tube 15 of the reaction tower 10 is connected to the outer tube of the raw material heater 7, and 1 g of the mixed gas flowing in the inner tube 6 of the raw material heater 7 is heated by heat exchange. At the same time, 1 g of the mixed gas flowing out from the reaction tube 15 is cooled. Further, the not-shown outer tube side of the raw material heater 7 is connected to the methane synthesis tower 40 filled with the methanation catalyst 40a, and remains in 1 g of the mixed gas cooled by heat exchange in the raw material heater 7. Carbon monoxide (CO), carbon dioxide (CO ₂ ) and hydrogen (H ₂ ) are reacted to produce methane (CH ₄ ).

The methane synthesis tower 40 is connected to a raw material evaporator 4 for evaporating the raw material 1a, and cools the methanated mixed gas 1h by heat exchange with the liquid raw material 1a flowing through the inner pipe 3. Furthermore, the outer pipe side (not shown) of the raw material evaporator 4 is
It is connected to the gas-liquid separator 43 via the gas cooler 42.
The gas-liquid separator 43 is cooled by the gas cooler 42 and remains unreacted water vapor (H ₂ O) in the mixed gas 1h.
Liquefies and separates this water. Furthermore, the gas-liquid separator 43
Is connected to an adsorption separation column 44 filled with an adsorbent such as fluorite, and separated into a mixed gas 1j containing methane (CH ₄ ) as a main component and an off gas 1k containing carbon dioxide (CO ₂ ) as a main component. It

Further, the adsorption separation tower 44 has a heat quantity adjusting mixer 45.
This heat quantity adjusting mixer 45 has a predetermined ratio of a part of the raw material 1a evaporated in the raw material evaporator 4 to the mixed gas 1j containing methane (CH ₄ ) as a main component and flowing out from the adsorption separation column 44 at a predetermined ratio. And mixed so that the amount of heat is adjusted to a predetermined value to produce 1 liter of gas.

On the other hand, 47 is a boiler, and this boiler 47 uses a part of the raw material 1a evaporated in the raw material evaporator 4 as fuel.
From the valve 48 that regulates the inflow of 1 m of soft water, 1 m of soft water preheated through the first boiler feed water preheater 49 that exchanges heat with the exhaust gas from the heating chamber 13 of the reaction tower 10 is steam (H ₂ O). It becomes 1e. The combustion of the fuel is performed by appropriately supplying air with the blower 50. A combustion chamber 51 including a burner (not shown) is connected to the boiler 47, and the combustion chamber 51 is connected to the boiler 47.
The combustion gas from 47 and the air from the blower 50 are supplied, and the off gas 1k flowing out from the adsorption separation column 44 is burned as a fuel. This combustion gas is the kiln mouth of the kiln body 14 of the reaction tower 10.
It flows from 17 into the heating chamber 13, and while heating the reaction tube 15, rises spirally inside the heating chamber 13 and is exhausted from the exhaust port 18.

Further, a steam heater 52 is connected to the boiler 47, and the steam (H ₂ O) 1e formed in the boiler 47 is circulated in the inner tube 53 of the steam heater 52, and the kiln of the reaction tower 10 is heated. The steam (H ₂ O) 1e is heated by heat exchange with the exhaust gas exhausted from the exhaust port 18 of the body 14. Then, the heated steam (H ₂ O) 1e flows into the second raw material mixer 9. Furthermore, the reaction tower 10 that has undergone heat exchange with the steam heater 52
Exhaust gas from the is introduced into the boiler feedwater preheater 49 and heat exchange with the soft water 1 m, the soft water 1 m is heated and the exhaust gas is cooled, and from the exhaust means 55 such as a chimney to the atmosphere via the intake blower 54. Exhausted. The exhaust means 55 is preferably provided with an exhaust gas cleaning means for cleaning and exhausting exhaust gas.

Next, the operation of the above embodiment will be described.

The butane (C ₄ H ₁₀ ) 1a, which is a liquid raw material of about 7 kgf / cm ² in the raw material tank 1, is caused to flow into the inner pipe 3 of the raw material evaporator 4 and the outside of the raw material evaporator 4 not shown. It is vaporized by heat exchange with the mixed gas generated in the methane synthesis tower 40 flowing through the tube side. Then, the vaporized butane gas (C ₄ H ₁₀ ) 1a is caused to flow into the first raw material mixer 5,
This butane gas (C ₄ H ₁₀ ) 1a is recycled gas compressor
The recycled gas 1b from 39 is mixed appropriately, for example, so that the molar ratio of butane (C ₄ H ₁₀ ) 1a and hydrogen (H ₂ ) in the recycled gas 1b is, for example, 10: 1. In addition, butane gas (C
₄ H ₁₀ ) 1a is caused to flow into the inner tube 6 of the raw material heater 7 and the reaction tower
It is heated to a predetermined temperature, for example, about 350 ° C. by heat exchange with 1 g of the mixed gas generated in 10.

Then, the heated butane gas (C
The mixed gas 1c of ₄ H ₁₀ ) 1a and recycled gas 1b is caused to flow into the desulfurizer 8, and the nickel-molybdenum (Ni—Mo) -based hydrogenation catalyst in the first desulfurization chamber 8a and the second desulfurization Room
In the cobalt-molybdenum (Co-Mo) -based hydrogenation catalyst (COMOX) in 8b, unsaturated hydrocarbons in the raw material 1a are saturated hydrocarbons (C ₂ ) by hydrogen (H ₂ ) in the recycle gas 1b.
_n H _{2n + 2} ) and the sulfur (S) of hydrogen sulfide (H ₂ S) in the mixed gas 1c is adsorbed by the ZnO (zinc oxide) adsorbent in the third desulfurization chamber 8c. Adsorbs with zinc (Zn) as an agent to become zinc sulfide (ZnS), and H ₂ S
H ₂ of the ZnO-based adsorbent is combined with oxygen (O) to form H ₂ O.
To produce the desulfurization reaction shown in Chemical formula 7,

[Chemical 7] Occurs.

Next, the desulfurized mixed gas flows into the second raw material mixer 9, and medium steam of about 7 kgf / cm ² generated in the boiler 47 in the second raw material mixer 9 ( H ₂ O) 1e
Of butane (C ₄ H ₁₀ ) 1a, water vapor (H ₂ O) 1e, and hydrogen (H ₂ ) in the recycled gas 1b have a molar ratio of, for example, 1
Mix to a ratio of 0: 30: 1. Then, this mixed gas of butane (C ₄ H ₁₀ ) 1a, steam (H ₂ O) 1e and recycle gas 1b is reformed from the inlet 25 of the reaction tube 15 of the reaction tower 10 heated by a burner (not shown). The butane (C ₄ H ₁₀ ) 1a is made to flow into the chamber 33 and filled in the reforming chamber 33 with a nickel-based reforming catalyst to hydrogen (H ₂ ), carbon monoxide (CO) and carbon dioxide (CO). ₂ ) and methane (CH
The mixed gas 1f of ₄ ) is subjected to a reaction, that is, the reactions shown in Chemical formulas 1 to 5 to reform. Further, the reformed mixed gas 1f flows from the reforming chamber 33 of the reaction tube 15 into the methanation chamber 34 via the catalyst supporting portion 30, and is reformed by the filled nickel-based methanation catalyst. Reaction of generating methane (CH ₄ ) with carbon monoxide (CO) and carbon dioxide (CO ₂ ) and hydrogen (H ₂ ) in the gas 1f, that is,
And methanation in the reaction shown in Chemical formula 6. In addition,
A part of the mixed gas 1f reformed in the reforming chamber 33 is discharged as a recycled gas 1b from the recycled gas outflow pipe 35 to the outside of the reaction tower 10, cooled by a recycled gas cooler 37, and a recycled gas gas-liquid separator. It is used as a recycled gas 1b after gas-liquid separation at 38 and compression by a recycled gas compressor 39.

Then, 1 g of the mixed gas reformed and methanated in the reaction tower 10 flows out from the outlet 31, is cooled by heat exchange in the raw material heater 7, flows into the methane synthesis tower 40, and is filled with the meta. Nation catalyst 40a mixed gas 1g
Residual carbon monoxide (CO), carbon dioxide (C
O ₂ ) and hydrogen (H ₂ ) are reacted to produce methane (C
H ₄ ).

Mixed gas flowing out of this methane synthesis tower 40
1 h is cooled by heat exchange with the raw material 1 a via the raw material evaporator 4, further cooled by the gas cooler 42, and then liquefied by the gas-liquid separator 43, and unreacted residual water vapor (H ₂ O) 1e is separated and removed. And mixed gas 1i
Is separated into a mixed gas 1j containing methane (CH ₄ ) as a main component and an off gas 1k containing carbon dioxide (CO ₂ ) as a main component by an adsorbent (not shown) filled in the adsorption separation column 44. . After that, the mixed gas 1j containing methane (CH ₄ ) as a main component flows into the heat quantity adjusting mixer 45, and a part of the butane gas (C ₄ H ₁₀ ) 1a evaporated in the raw material evaporator 4 has a predetermined amount. The heat is mixed so that 1 liter of gas is produced. In addition,
The off gas 1k is used as a fuel for heating the reaction tube 15 of the reaction tower 10.

Therefore, after desulfurization, steam (H ₂ O) 1e
The butane gas 1a and the recycled gas 1b, which are mixed raw materials, are mixed gas 1f containing hydrogen (H ₂ ), carbon dioxide gas (CO, CO ₂ ) and methane (CH ₄ ) as main components with a nickel-based reforming catalyst. At the center axis of the reforming chamber 33 for endothermic reaction, the nickel-based methanation catalyst communicates the carbon dioxide gas (CO, CO ₂ ) and hydrogen (H ₂ ) of the mixed gas 1f with methane. Since the methanation chamber 34 for causing exothermic reaction to (CH ₄ ) is arranged substantially coaxially and formed into a double pipe structure, methanation and steam reforming can be performed by one device, and the device can be simplified and downsized. Construction can be done easily.

Further, since the reforming chamber 33 for endothermic reaction is located on the outer peripheral side, it is possible to efficiently heat with the burner and
The heat generated by the exothermic reaction of the methanation chamber 34 can be efficiently transmitted to the reforming chamber 33, which is an endothermic reaction, and the amount of heat supplied from the outside by a burner or the like necessary for the endothermic reaction of the reforming chamber 33 can be reduced, and gasification can be performed at low cost it can.

Further, since the raw material 1a is once pressurized to a high pressure to produce a gas and the gas is not decompressed and supplied up and down, equipment for pressure operation is not required and production efficiency can be improved. Cost can be reduced.

[0040]

EXAMPLES An example of gasifying butane (C ₄ H ₁₀ ) 1a as a raw material using the medium pressure continuous gasifier of the above embodiment will be described with reference to FIG. 1 and Table 1. To do.

First, as a raw material, 2
Butane stored in a liquid of about 9.5 kgf / cm ² at 5 ° C (C
₄ H ₁₀ ) 1a is used.

Then, butane (C ₄ H ₁₀ ) 1a is evaporated in the raw material evaporator 4 and gasified into butane gas (C ₄ H ₁₀ ) 1a at a pressure of 9.0 kgf / cm ² at 110 ° C. In the raw material mixer 5, butane gas (C ₄ H ₁₀ ) 1a and recycled gas 1b
So that the molar ratio with hydrogen (H ₂ ) in the mixture is 10: 1,
Recycle gas 1b having a pressure of 9.2 kgf / cm ² at 110 ° C. is mixed. Then, butane gas (C ₄
The mixed gas 1c of H ₁₀ ) 1a and recycled gas 1b is about 330
After being heated to ℃ and desulfurized by the desulfurizer 8, at the second raw material mixer 9 at 330 ℃, 10.0 kgf / cm ² of steam 1e, butane (C
₄ H ₁₀₎ 1a, steam (H ₂ O) 1e, the molar ratio of hydrogen in the recycle gas 1b (H ₂₎ 10: 30: mixed so that 1.

Next, by heating from the burner, about 600 ° C.
The mixed gas 1f shown in Table 1 is reformed by flowing into the reforming chamber 33 of the reaction tube 15 of the reaction tower 10 heated to the above. Further, a part of the reformed mixed gas 1f is withdrawn from the recycled gas outflow pipe 35, and the rest is methanated in the methanation chamber 34 to generate mixed gas 1g shown in Table 1.

[0044]

[Table 1] Thereafter, 1 g of the mixed gas is cooled to about 500 ° C. in the raw material heater 7, and carbon monoxide (CO), carbon dioxide (CO ₂ ) and hydrogen (H ₂ ) remaining in the mixed gas 1 g are mixed in the methane synthesis tower 40.
₂ ) is reacted with methane (CH ₄ ) to produce a mixed gas 1h shown in Table 1. Then, the mixed gas 1h cooled from the methane synthesis tower 40 via the raw material evaporator 4 and the gas cooler 42
The unreacted water vapor (H ₂ O) is separated by the gas-liquid separator 43,
The mixture gas 1i containing methane (CH ₄ ) as the main component and the off gas 1k containing carbon dioxide (CO ₂ ) as the main component shown in Table 1 were separated in the adsorption separation column 44, and the heat amount adjusting mixer 45 was used to form the table 2 The butane gas (C ₄ H ₁₀ ) 1a vaporized so that the heat generation amount becomes 11000 kcal / Nm ³ is mixed to produce the gas 1l shown in Table 1.

Note that the water pane densities (WI) are shown in the equation (1), and the combustion speed (MCP) is calculated from the equation (2). Table 3 shows each variable in these equations 1 and 2.

[Equation 1]

[Equation 2]

[Table 2]

[Table 3]

[0046]

According to the medium-pressure continuous gasifier of the present invention, the raw material mixed with steam after desulfurization is converted into a mixed gas containing hydrogen, carbon dioxide and methane as main components by the nickel-based reforming catalyst. A methanation chamber, which causes carbon dioxide and hydrogen of nickel-based methanation catalyst mixed gas to exothermically react with methane, is arranged in the central axis of the reforming chamber for endothermic reaction in a coaxial manner to form a double pipe structure. Since it is formed, methanation and steam reforming can be done in one device, the device can be easily downsized, the installation of the device can be facilitated, and the heat due to the exothermic reaction of the methanation chamber can be efficiently transferred to the reforming chamber. The amount of heat supplied from the outside necessary for the endothermic reaction in the reforming chamber can be reduced, and gasification can be performed at low cost.

[Brief description of drawings]

FIG. 1 is a system explanatory view showing an embodiment of a medium-pressure continuous gasifier of the present invention.

FIG. 2 is a cross-sectional view showing the same reaction tower.

FIG. 3 is a system explanatory diagram showing a conventional medium-pressure continuous gasifier.

[Explanation of symbols]

 1a Raw material 1e Steam 8 Sulfurizer 10 Reaction tower which is a medium pressure continuous gasifier 15 Reaction tube 25 Inlet 31 Outlet 33 Reforming chamber 34 Methanation chamber

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C10G 11/20 9279-4H C10G 11/20 // C07B 61/00 300 C07B 61/00 300

Claims (1)

[Claims] 1. A nickel-based reformer for introducing a raw material mixed with water vapor after desulfurization into which the raw material flows, and communicating the raw material with a mixed gas containing hydrogen, carbon dioxide and methane as main components. A reforming chamber having a catalyst; a methanation chamber having a nickel-based methanation catalyst that communicates with the reforming chamber and causes carbon dioxide and hydrogen of the mixed gas flowing out of the reforming chamber to react with methane; An outlet for communicating a gas containing methane as a main component from the methanation chamber, the methanation chamber being arranged substantially coaxially with the center axis of the reforming chamber. A medium-pressure continuous gasifier characterized by having a double-pipe structure.