JP3526222B2 - Gas conversion melting furnace - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an improvement in a gas conversion melting furnace for converting a thermal decomposition product of waste into a fuel gas.

[0002]

2. Description of the Related Art Waste is pyrolyzed, and its pyrolyzed products (pyrolysis gas, pyrolysis oil, pyrolysis residue) are put into a gas conversion melting furnace and subjected to high temperature treatment by oxygen addition to remove ash. As a slag, a technique of recovering organic matter as fuel gas is known.

FIG. 3 is a flow chart showing a conventional gas conversion melting furnace, in which waste is pyrolyzed by the pyrolysis furnace 1 and the pyrolysis gas containing tar is cooled and washed by the condenser 2. It is divided into pyrolysis gas and pyrolysis oil. The thermal decomposition residue is crushed by the crusher 3. These are directly charged into the gas conversion melting part 5 of the gas conversion melting furnace 4. The gas conversion melting part 5 is kept at a high temperature of 1400 to 2000 ° C. by adding oxygen.

However, in the conventional gas conversion melting furnace, the main purpose of the pyrolysis gas and pyrolysis oil is to reform the fuel gas containing CO and H ₂ as main components by performing gas cracking. Although the temperature required for gas cracking is 1000 to 1300 ° C, the gas conversion melting part 5 at 1400 to 2000 ° C
However, there is a problem in that wasteful heat is consumed, oxygen is supplied in large amounts, and gasification efficiency is poor.

Further, since the pyrolysis gas and the pyrolysis oil are directly fed to the gas conversion melting section 5, hydrogen atoms contained in the pyrolysis gas and the pyrolysis oil react with the introduced oxygen to generate H ₂ O is generated. Therefore, there is a problem that the amount of hydrogen in the recovered fuel gas is reduced. The main reactions that take place in the gas conversion / melting section 5 are as follows.

[0006]

[Chemical 1]

[0007]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned problems of the prior art, and produces a fuel gas having a high gasification efficiency and a high hydrogen content rate from the thermal decomposition products of wastes without wasting heat. This is done to provide a gas conversion melting furnace that can be efficiently obtained.

[0008]

The gas conversion melting furnace of the present invention made to solve the above problems is connected to a waste thermal decomposition furnace to convert the thermal decomposition products into fuel gas. The inside of the furnace body of the melting furnace maintained at 5-30 atm ,
Gas conversion melting part at 1400 ° C- 2000 ° C and below
Located at 1000 ° C. to 1300 ° C., and the pyrolysis residue of the pyrolysis products is introduced into the gas conversion melting section, and the pyrolysis gas and pyrolysis oil are not separated. A gas conversion melting furnace adapted to be introduced into a gas cracking section , wherein the pyrolysis furnace is
Pyrolysis of waste under higher pressure than gas conversion melting furnace
It is characterized by having done. Incidentally, the gas cracking unit of this, it is preferable to provide a supply line of the flow rate controllable oxygen and methane.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail below together with preferred embodiments. FIG. 1 shows a first embodiment of the present invention, in which the inside of a furnace body 10 of a gas conversion melting furnace kept at a high pressure of 5 to 30 atm is provided with a gas conversion melting part 1
1 and a gas cracking section 12 and a quenching section 19 located below it . The gas conversion melting portion 11 is a high temperature as in the prior art to 1400 to 2000 ° C., under which
The gas cracking part 12 provided adjacent to
The temperature is set to 000 to 1300 ° C. Oxygen is supplied to the gas conversion / melting section 11 from the oxygen supply line 13. Further, the gas cracking portion 12 is maintained at a low oxygen concentration. The gas cracking section 12 is preferably provided with an oxygen supply line 14 and a methane supply line 15 whose flow rates can be controlled.

Reference numeral 16 denotes a waste thermal decomposition furnace installed in the preceding stage of the gas conversion melting furnace, which thermally decomposes the waste at a temperature of about 550 ° C., and the thermal decomposition gas containing thermal decomposition oil and the thermal decomposition residue. It is a char. The thermal decomposition residue is pulverized by a pulverizer 17 and then introduced into the gas conversion / melting section 11, where the above-mentioned 1,
It is mainly converted into CO gas and recovered by the two equations. On the other hand, the pyrolysis furnace gas containing pyrolysis oil heat in the condenser 18
It is separated into cracked oil and pyrolysis furnace gas, and both are put into the gas cracking section 12. Thus pyrolysis oy
In order to separate the gas and the pyrolysis furnace gas into the furnace body 10 of the gas conversion and melting furnace kept at a high pressure of 5 to 30 atm, these are smoothly pumped using dedicated pumps for gas and liquid respectively. This is to send by pressure. 1300 ° C. in a low oxygen concentration below the cracking reactions occurring in the gas cracking unit 12 below 7
According to the formula, the fuel gas containing CO and H ₂ as main components can be recovered from the quenching section 19.

According to the gas conversion melting furnace of the present invention, the pyrolysis oil and the pyrolysis gas are introduced into the gas cracking section 12 at a temperature lower than that of the gas conversion melting section 11, so that the heat quantity can be reduced for the following reasons. it can. 1) The amount of sensible heat that raises the pyrolysis oil and the pyrolysis gas to the reaction temperature can be reduced. 2) In the gas cracking section 12, the gas conversion melting section 1
The sensible heat of hot gas from 1 to 1400 ℃ or higher can be used for the reaction. Since the amount of oxygen supplied can be reduced by reducing the required heat amount, the gasification efficiency of the produced fuel gas is increased.

[0012]

[Chemical 2]

These equations 7 and 6 are the gas cracking section 1
It becomes the main reaction in 2. The equilibrium reaction of equation 6 is a reaction that moves to the right as the temperature rises. In the gas conversion / melting furnace of the present invention, only the thermal decomposition residue is put into the gas conversion / melting section 11, so that the reactions of the above three equations in the gas conversion / melting section 11 are reduced, and conversely, the gas cracking section 12 The hydrogen generation amount increases because the reaction of the equation ( 7) occurs. In addition, the gas cracking section 12 has a lower temperature than the gas conversion and melting section 11, so that the equilibrium advances to the left and the hydrogen generation amount increases.

As described above, in the gas conversion melting furnace of the present invention, the pyrolysis oil and the pyrolysis furnace gas are mixed in the gas conversion melting section 1
In order to put it in the gas cracking section 12 at a temperature lower than 1,
Compared with the conventional method in which the gas conversion and melting section at 1400 ° C or higher is used, the heat consumption can be reduced and the oxygen supply can be reduced,
The gasification efficiency of the recovered fuel gas can be increased. Further, according to the gas conversion melting furnace of the present invention, the amount of hydrogen in the recovered fuel gas can be increased.

Since hydrogen has a higher added value than methane, methane can be fed from the methane supply line 15 to the gas cracking section 12 as an auxiliary agent to increase the amount of hydrogen generated. If necessary, oxygen can be introduced into the gas cracking unit 12 from the oxygen supply line 14 to control the properties of the fuel gas.

FIG. 2 shows a second embodiment of the present invention. In this embodiment, the high-pressure pyrolysis furnace 20 is installed in the preceding stage of the gas conversion melting furnace, and the waste is pyrolyzed under a higher pressure than that of the gas conversion melting furnace. In this embodiment, the gas cracking unit 1 of the gas conversion melting furnace is utilized by utilizing the pressure difference without separating the pyrolysis furnace gas from the pyrolysis oil.
2 can be thrown in. Therefore, it is not necessary to separate the pyrolysis oil in the condenser 18 as in the first embodiment, and the heat consumption can be further reduced. Also, the first
In the second embodiment, the water-soluble polymer organic matter lost in the condenser 18 enters the gas cracking section 12 in the second embodiment, so that the recovery amount of the fuel gas can be increased.

Next, a calculation example for confirming the effect of the present invention will be shown. The calculation was performed for the gas conversion melting furnace of the present invention shown in FIG. 1 and the conventional gas conversion melting furnace shown in FIG. As a premise of the calculation, the gas conversion melting temperature is 16
00 ° C (in the present invention, the gas cracking part is 1200 ° C),
In both cases, the amount of pyrolysis gas supplied was 300 Nm ³ , the amount of pyrolysis oil supplied was 1200 kg, and the amount of pyrolysis char supplied was 1000 kg. The results are as follows.

[0018]

[Table 1]

[0019]

As described above, according to the present invention, the gasification efficiency can be improved by reducing the heat consumption of the gas conversion process. In addition, the amount of hydrogen in the recovered fuel gas can be increased. Further, as described in claim 2, if a high-pressure pyrolysis furnace is used in the preceding stage, the water-soluble polymer organic matter enters the gas cracking section, so that the recovery amount of the fuel gas can be increased and the gas conversion process. It is possible to further reduce the heat consumption of.

[Brief description of drawings]

FIG. 1 is a flowchart showing an embodiment of the invention of claim 1.

FIG. 2 is a flow chart showing an embodiment of the invention of claim 2;

FIG. 3 is a flowchart showing a conventional example.

[Explanation of symbols]

1 Pyrolysis furnace, 2 Condenser, 3 Crusher, 4 Conventional gas conversion melting furnace, 5 Gas conversion melting section, 10 Gas conversion melting furnace furnace body of the present invention, 11 Gas conversion melting section, 12 Gas cracking section, 13 Oxygen supply line to gas conversion / melting section, 14 Oxygen supply line to gas cracking section, 15 Methane supply line, 16 Waste thermal decomposition furnace, 17 Crusher, 18 Condenser, 19 Quenching section, 20
High pressure pyrolysis furnace

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI F23G 5/14 B09B 3/00 ZAB F23K 5/00 303 303K (56) Reference JP 2000-70894 (JP, A) JP JP-A-55-51475 (JP, A) JP-A-11-294726 (JP, A) JP-A-11-290810 (JP, A) JP-A-11-281022 (JP, A) JP-A-11-270823 (JP , A) JP 11-216445 (JP, A) JP 11-193913 (JP, A) JP 11-173523 (JP, A) JP 11-169818 (JP, A) JP 11-159721 (JP, A) JP 10-339416 (JP, A) JP 10-337555 (JP, A) JP 10-310783 (JP, A) JP 10-205723 (JP, A) JP-A-10-156314 (JP, A) JP-A-10-132237 (JP, A) JP-A-10-130662 (JP , A) JP-A-10-128288 (JP, A) JP-A-10-81885 (JP, A) JP-A-9-229324 (JP, A) JP-A-5-126327 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F23G 5/00-5/50 F23K 5/00-5/22 B09B 3/00 C10K 3/00

Claims (2)

(57) [Claims] 1. A connected to the pyrolysis furnace waste, 5 gas conversion melting furnace of the furnace body for converting heat decomposition products into the fuel gas
The inside kept at 30 atm was 1400 ° C. to 2000 ° C., and the gas conversion and melting part was located below it.
It is divided into a gas cracking section at 1300 ° C., and the thermal decomposition residue of the thermal decomposition products is introduced into the gas conversion melting section,
In the gas conversion melting furnace, the pyrolysis gas and pyrolysis oil are put into the gas cracking section without separation.
There is a higher pressure in the pyrolysis furnace than in the gas conversion melting furnace.
A gas conversion melting furnace characterized in that waste is pyrolyzed below . 2. The gas conversion melting furnace according to claim 1, wherein the gas cracking section is provided with oxygen and methane supply lines whose flow rates can be controlled.