JP2002226869A - Method and equipment for producing synthesis gas - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a synthesis gas and an equipment therefor enabling the synthesis gas to be mass-produced at low cost using both inexpensive water and a solid carbonaceous material as raw materials. SOLUTION: This method for producing a synthesis gas comprises the following process: multi-phase alternate current electrodes 36, 38 and 40 are disposed in an arc plasma reactor 14, an arc reaction chamber 34 is packed with a solid carbonaceous material so as to form numerous fine arc passages 35 among the gaps of the carbonaceous material, an arc plasma is generated in the fine arc passages, and steam is reacted under contact with the carbon while feeding the steam into the fine arc passages.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a synthesis gas and an apparatus therefor, and particularly to a method for producing a synthesis gas containing hydrogen and Co useful as a raw material for the chemical industry and an apparatus therefor.

[0002]

2. Description of the Related Art Conventionally, synthesis gas is generally produced by reforming natural gas or coal gasification. However, these gases consume a large amount of heat energy for partial oxidation or steam reforming. The cost increases. In addition, since a part of the raw material is consumed for generating thermal energy for partial oxidation or steam reforming, the utilization efficiency of the raw material is low. Furthermore, the synthesis gas generated by the above method contains sulfur, and cannot be completely removed. In this case, for example, when a hydrocarbon fuel is produced from the synthesis gas, the catalyst is immediately deactivated due to the sulfur content, which makes the catalyst unsuitable as an industrial raw material.

[0003] US Patent No. 5,159,900 proposes an apparatus for generating a synthesis gas by causing carbon electrodes to face each other in water in a tank and generating an arc between the electrodes. U.S. Pat. Nos. 5,435,274 and 5,692,549 propose an apparatus for generating synthesis gas by generating an arc between carbon electrodes in water.

[0004]

The conventional arc discharge type syngas production apparatus has an extremely small area where an arc is generated, has no carbon material in the middle of the counter electrode, and has steam only at the tip of the carbon electrode. And is converted to synthesis gas. For this reason, the amount of synthesis gas generated per unit electric energy is extremely small and cannot be used industrially. Furthermore, the above-mentioned synthesis gas production apparatus is inevitably increased in size due to the arrangement structure of the carbon electrodes, making it difficult to reduce the cost of the apparatus. Moreover, in the above-described method, the amount of ionized ions generated is small, so that an arc cannot be generated stably and continuously. Therefore, the synthesis gas generation efficiency is extremely low.

Accordingly, the present invention provides a synthesis gas production method and apparatus capable of continuously mass-producing synthesis gas with extremely high efficiency using inexpensive water and an inexpensive solid carbon material as starting materials. The purpose is to.

[0006]

According to a first concept of the present invention, a synthesis gas production method includes an insulating casing having a raw water supply port and a synthesis gas outlet, and an arc plasma reaction formed in the insulation casing. Preparing an arc plasma reactor having a chamber and an arc electrode disposed in the arc plasma reaction chamber; filling a solid carbon material into the arc plasma reaction chamber to form a large number of minute gaps in the solid carbon material; Forming an arc passage; supplying an arc force to the arc electrode to generate a minute arc plasma in the minute arc passage; dividing the raw water or steam introduced from the raw water supply port into a number of minute flows. Containing hydrogen and carbon monoxide by contacting and reacting a minute stream of water vapor with the carbon of the solid carbon material in the presence of arc plasma. Producing syngas.

According to a second concept of the present invention, a cylindrical insulating casing having a carbon material feed port, a raw water supply port, and a synthesis gas outlet; arc plasma formed in the cylindrical insulating casing A reaction chamber; an insulating electrode holder supported by an insulating casing; an arc electrode supported by the electrode holder and extending to the arc plasma reaction chamber to generate arc plasma by arc power supplied from a plasma power supply; A solid carbon material which is filled in the plasma reaction chamber and generates a micro arc plasma by sparks in the gap and forms a large number of micro arc passages for dividing the raw water or steam into a large number of micro flows. Water or water vapor reacts with carbon in the presence of a micro-arc plasma while passing through the micro-arc path Achieved by generating synthesis gas.

[0008]

According to the method and the apparatus for producing a synthesis gas of the present invention, a minute arc passage formed in an arc plasma reactor is formed of a solid carbon material, and ionized ions are continuously generated in the minute arc passage. A large amount of small arc plasma is generated by sparks, steam is introduced into the small arc passage, and the steam reacts with the carbon of the carbon material in the presence of the arc plasma to produce a stable arc continuously. While efficiently generating a synthesis gas composed of carbon monoxide and hydrogen containing no sulfur as shown in the following equation.

C + H ₂ O → Co + H ₂
(1) Co + H ₂ O → CO ₂ + H ₂ (2)

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a syngas production apparatus according to a preferred embodiment of the present invention will be described with reference to the drawings. In FIG. 1, a synthesis gas producing apparatus 10 includes an arc plasma reactor 14 connected to a carbon raw material charging apparatus 12.
, A multi-phase AC power supply 16 and a cooler H1. The raw material input device 12 includes a hopper 20 for storing a solid carbon raw material such as powdered, pelletized or massive graphite, granular activated carbon, spherical carbon or carbon powder, a screw feeder 22, and a rotary valve 24. 14 is charged with a carbon raw material. Plasma reactor 1
Reference numeral 4 denotes a cylindrical outer insulating casing 26 made of a heat-resistant ceramic, and an inner insulating casing 32 having an arc plasma reaction chamber 34, and an insulating electrode holder 28 attached to the upper end of the casing by a bolt 30. When the granular carbon material is supplied into the arc plasma reaction chamber 34,
A large number of minute arc passages 35 are formed in the plasma arc reaction chamber 34.
This causes the water vapor to be divided into a number of minute streams, and a large amount of small plasma arcs due to sparks are uniformly generated in the minute arc passages when power is supplied to the arc electrodes. The raw water turns into steam due to the high temperature on the upstream side of the plasma arc reaction chamber 34, and a minute flow of the steam contacts and reacts with the carbon of the carbon material while passing through the minute arc passage to produce synthesis gas as in the above-mentioned reaction formula. Is done.

The insulating holder 28 is a rod-shaped multi-phase AC electrode 3
6, 38 and 40 are supported. Below the insulating casing 32, a disc-shaped ground electrode 42 for emitting thermoelectrons for arc generation is arranged. A cylindrical arc plasma reaction chamber 34 is formed inside the inner insulating casing 32. The ground electrode 42 is supported by an electrode holder 78 formed at the lower end of the insulating casing 26, and is fixed by bolts 80. The electrode holder 28 has a carbon material supply port 50 connected to the carbon material charging device 12. A raw water supply port 52 for introducing raw water or water vapor is disposed adjacent to and above the arc electrodes 36, 38, and 40 above the insulating cane 26. The reason is that the arc electrode is effectively cooled by the raw water or steam to prevent an abnormal temperature rise of the arc electrode. A preheating portion 63 formed of a spiral cooling passage 54 is formed on the outer periphery of the inner casing 32, and these cooling passages communicate with each other through a communication passage 64. The insulating casing 26 has an inlet 74 and an outlet 76, the inlet 74 is connected to a raw water supply pump, and the outlet 76 is connected to the raw water supply port 5.
Communicates with 2. An end plate 82 is fixed to a flange portion 78 constituting a lower end portion of the insulating casing 26 via a bolt 80, and a sealing material 83 is disposed between them. 0.2 at the lower end of the arc plasma reaction chamber 34
A filter 84 having an average aperture of about 0.5 μm is supported by the end plate 82. The end plate 82 has a synthesis gas outlet 86. Reference numeral 88 indicates a seal member disposed between the electrode holder 28 and the casings 26 and 32.

The three-phase AC arc electrodes 36, 38, 40 are connected to the plasma power supply 16, and the neutral electrode 4 is connected to the neutral point.
2 are connected. Three-phase AC electrode 3 from plasma power supply 16
6, 38, 40 and neutral electrode 42, output frequency 5
0-60Hz, output voltage 30-240V, output current 50
-200 A three-phase AC power is supplied. At this time, of the three-phase AC electrodes 36, 38, and 40, current flows alternately from the two electrodes and the three electrodes to the neutral electrode 42, and arc plasma is generated in the gap between the carbon raw materials by sparks. In accordance with the phase of the three-phase alternating current, the generation position of the plasma arc continuously changes, a large amount of ionized ions are constantly supplied to the gap between the carbon raw materials, and thermions are constantly emitted from the ground electrode 42. In addition, a plasma arc is generated stably and continuously.

A method for producing a synthesis gas according to a preferred embodiment of the present invention will be described with reference to FIG.

Step 1 (hereinafter abbreviated as ST): feed water supply port 52, synthesis gas outlet 86, insulating casing 32, arc plasma reaction chamber 34 formed in the insulating casing, and arc plasma reaction chamber An arc plasma reactor 14 including the arranged multi-phase AC electrodes 36, 38, 40 and the ground electrode 42 is prepared.

ST2: Arc Plasma Reaction Chamber 34
Is filled with a solid carbon material to form a minute arc passage 35 in a gap between the carbon materials.

ST3: Arc electrodes 36, 38, 40
A multi-phase AC power is supplied between the power supply and the ground electrode 42 to generate a micro arc plasma passing through a large number of micro arc passages 35. At this time, the temperature in the reaction chamber is set to 800 to 100
The input voltage is controlled to be within the range of 0 ° C. This is because in this temperature range, the hydrogen generation ratio with respect to Co is in the range of 2 to 5, and the molar ratio of Co / H in the synthesis gas can be adjusted to an appropriate range.

ST4: Raw water or water vapor H ₂ O is passed through the raw water supply port 52 into the minute arc passage 35 to cause a minute flow of water vapor and carbon of the coal cord material to react in the presence of arc plasma, As described in the above reaction formulas (1) and (2), a synthesis gas containing hydrogen and carbon monoxide is generated.

Next, the operation of the synthesis gas producing apparatus 10 shown in FIG. 1 will be described. In FIG. 1, first, the screw feeder 22 and the rotary valve 24 are driven to fill the arc plasma reactor 14 with a carbon material such as granular activated carbon to a predetermined level. At that time, the rotary valve 24
Then, the screw feeder 22 is stopped. Next, after the raw water introduced from the feed water pump P1 is preheated by passing through the preheating unit 63, the raw water is supplied to the raw water supply port 52, and three-phase AC power is supplied to the arc electrode of the arc plasma reactor 14. . At this time, the raw water supplied from the raw water supply port 52 to the arc plasma reaction chamber 34 is converted into steam at a high temperature near the upstream thereof, is divided into a large number of minute flows, and flows into a large number of minute arc passages. The minute stream of water vapor passes from the upstream to the downstream of the arc plasma reaction chamber. At this time, the water vapor passes through the minute arc passage 35 while reacting with carbon to generate a large amount of synthesis gas, and is discharged from the outlet 86.

In the above embodiment, a temperature sensor is attached to a three-phase AC electrode or an insulating casing to generate a temperature signal, and the temperature signal is compared with an optimum reference temperature signal stored in a computer to output an output of a three-phase AC power source composed of an inverter. The operating temperature in the arc plasma reaction chamber may be constantly maintained at a stable level by controlling the frequency or the output voltage to a predetermined level.

The syngas production method and apparatus according to the present invention have the following advantages. (1) In order to use extremely inexpensive water and inexpensive solid carbon materials instead of natural gas as starting materials for synthesis gas,
The raw material cost can be significantly reduced, and the cost of synthesis gas can be significantly reduced. (2) Using a small, high-performance arc plasma reactor,
Since a large amount of synthesis gas is generated, the production efficiency of synthesis gas is high. (3) Since all carbon materials are used only for syngas generation and are not used as fuel for combustion in the reformer, the utilization efficiency of raw materials is extremely high. (4) In the arc plasma reactor, the Co / H2 ratio in the synthesis gas can be changed depending on the operating temperature in the reactor reaction chamber, so that the operation control of the synthesis gas production plant can be easily optimized. (5) Conventionally, at the time of syngas production, a complicated process of periodically interrupting the syngas generation process and supplying air to the reformer to burn hydrocarbon fuel is required. Since these complicated processes are unnecessary, the operation control of the synthesis gas production plant is extremely simplified, and the operation cost can be greatly reduced. (6) In the present invention, a large number of minute arc passages are formed in the gaps between the carbon materials, and a large number of minute passages are continuously formed while dividing water vapor into a large number of minute flows and passing through the respective minute passages. Since the arc is generated in the inside, the contact efficiency between the water vapor and the arc is improved, and the production efficiency of the synthesis gas is dramatically improved. (7) In the method of the present invention, the start-up and the operation stop of the manufacturing plant can be instantaneously executed only by shutting off the supply of electric power to the arc electrode and turning on / off the power of the pump,
In particular, it is extremely safe in the event of emergency measures such as an earthquake, which is advantageous for safety measures to the surrounding residents. (8) The manufacturing apparatus of the present invention is small, compact, high-performance, and has a simplified manufacturing process. For,
Return on investment in a short time. (9) Since the synthesis gas production plant of the present invention is small, high-performance and safe, it can be installed adjacent to the final product synthesis plant, so that the transportation cost of synthesis gas can be reduced by that much, and the synthesis gas can be reduced. It is possible to prevent environmental destruction caused by truck transportation.

In the above embodiment, the arc plasma reactor has been described as supplying the raw water from the upstream and taking out the synthesis gas from the synthesis gas outlet provided downstream, but when the amount of slag generated is large depending on the type of carbon material, Alternatively, a raw water supply port may be provided downstream of the reactor, and a synthesis gas outlet may be provided upstream of the reactor to separate slag and synthesis gas by a cyclone. Although the plasma arc reactor is described as using a rod-shaped three-phase AC electrode, the three-phase AC electrode is cylindrically arranged at intervals in the axial direction and a rod-shaped ground disposed at the center thereof. You may comprise by an electrode.

[0022]

As is clear from the above, according to the method and apparatus for syngas production of the present invention, mass production of syngas is possible at extremely low cost, and the contribution to practical use is extremely high.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a synthesis gas production apparatus according to a preferred embodiment of the present invention.

[Explanation of symbols]

12 carbon material input device, 14 arc plasma reactor, 24 rotary valve, 26 outer casing, 2
8 electrode holder, 32 outer casing, 34 arc plasma reactor, 35 micro arc passage, 63 preheating section

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C01B 3/06 C01B 3/06

Claims (4)

[Claims] An arc plasma including an insulating casing having a raw water supply port and a synthesis gas outlet, an arc plasma reaction chamber formed in the insulation casing, and an arc electrode disposed in the arc plasma reaction chamber. A step of preparing a reactor; a step of filling a solid carbon material into an arc plasma reaction chamber to form a large number of minute arc passages in a gap between the solid carbon materials; Generating a minute arc plasma in the arc passage; dividing the raw water or steam into a plurality of minute flows from the feed water supply port and passing the divided water through the plurality of minute arc passages; Producing a synthesis gas containing hydrogen and carbon monoxide by contacting and reacting a micro flow with carbon of a solid carbon material. Manufacturing method. 2. The three-phase electrode according to claim 1, further comprising: a three-phase AC electrode having the arc electrode supported by the insulating casing; and a ground electrode spaced from the three-phase AC electrode. Characterized in that a plurality of arc plasmas are generated while rotating at the same time. 3. A carbon material feed port, a feed water supply port,
A cylindrical insulating casing having an outlet for syngas; an arc plasma reaction chamber formed in the cylindrical insulating casing; an insulating electrode holder supported by the insulating casing; and an arc plasma reaction chamber supported by the electrode holder. And an arc electrode extending from the plasma power supply to generate arc plasma by arc power supplied from a plasma power supply; and a ground supported by an insulating casing so as to be disposed at the other end of the arc plasma reaction chamber opposite to the arc electrode. An electrode; and a solid carbon material which is filled in the arc plasma reaction chamber and generates a minute arc plasma by sparks in the gap and forms a large number of minute arc passages for dividing the raw water or steam into a number of minute flows; The micro arc of the raw water or steam passes through the micro arc passage. An apparatus for producing synthesis gas, characterized in that it reacts with carbon in the presence of plasma to generate synthesis gas. 4. The syngas production according to claim 3, wherein the insulating casing comprises a concentric inner casing and an outer casing, and a preheating section disposed between the inner casing and the outer casing for preheating the raw water. apparatus.