JPS6223996B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention aims at complete recovery of tar by carbonizing coal using a multi-stage shaft furnace in which each stage is vertically connected through a throat section with a narrow inner diameter. The present invention provides a method that enables separation and recovery of high-calorie gas and low-calorie gas by separating tar. The conventional coal carbonization gasification method of this type is
There is a COED method, and this method has the following structure. After pulverizing and drying coal, tar and char are obtained by performing multi-stage carbonization. Each carbonization furnace has an operating temperature of 316°C (1st stage), 454°C (2nd stage), 538°C (3rd stage), and 810°C (4th stage) to prevent coal statesking from occurring in the fluidized bed.
It is said that The combustion of the third-stage char is the heat source. The carbonization product is separated into tar and char. However, this COED method has the following drawbacks. ○B It is not a complete gasification process. ○B Since a fluidized bed is used, the gasification efficiency is low at about 75%, and the char is produced. ○C Dry tar contains 3-10% of 0.2-2 micron fine powder. ○D Gas has low calories. The method of the present invention was devised to improve the drawbacks of the conventional method described above, and its gist is that a throat portion with a narrow inner diameter is provided in the middle of each stage furnace, and each Coal is charged into the top furnace of a vertical multi-stage shaft furnace with branch and conduit pipes for passing produced gas between the furnaces, and oxygen and steam are supplied to the bottom furnace to carbonize the coal. The top furnace or each intermediate furnace is branched and
This is a coal carbonization gasification method using a vertical multi-stage shaft furnace, which is characterized in that produced gas is optionally recovered from a conduit. Next, the method of the present invention will be explained with reference to the flowchart shown in FIG. The figure shows an example of a four-stage vertical shaft furnace in which four stage furnaces are connected vertically. Reference numerals 1 to 4 in the figure indicate each stage furnace, and throat parts 5 to 7 having a narrow inner diameter are provided in the middle of each stage furnace. Reference numeral 8 denotes a coal charging port provided at the top of the furnace in the uppermost stage passage 4, from which raw coal is charged. Reference numeral 9 denotes an inlet port provided at the lower side of the lowermost furnace 1 for introducing oxygen and steam. Reference numerals 10 to 12 are conduit pipes that extend outward from the furnace body and extend between the stages 1 to 4, and 13 is a branch pipe provided at the upper side of the uppermost furnace 4.
The produced gas is recovered from here.
Incidentally, although the branch pipe is also illustrated in the conduit pipe 12,
It can also be provided in the conduction pipes 10-11. 14
-16 are cutting rolls provided in the lower part of each stage furnace 2-4. 17 is an ash discharge port provided at the lower part of the lowest furnace 1. Therefore, in the coal carbonization gasification method of the present invention, as in the embodiment shown in FIG. 1 as a conceptual diagram, the amount of O ₂ charged from the lowermost furnace 1 is 469Kg (25℃), water vapor amount 387Kg
(300°C), and in this case, the temperature of the produced gas in the lowest stage furnace 1 is approximately 1000°C at the conduit pipe position, and the temperature of the produced gas in the upper second stage furnace 2 is approximately 748 to 740°C at the conduit pipe position, Furthermore, the temperature of the produced gas in the upper third stage furnace 3 is set at 410 to 400°C at the conduit pipe position, and the produced gas temperature in the uppermost stage furnace 4 is set at approximately 200°C at the branch pipe position, and the collected gas is recovered. In addition, the amount and temperature of the chir that descends within the shaft at this time are as follows. Top furnace → 3rd stage furnace: 966Kg, 350℃ 3rd stage furnace → 2nd stage furnace: 770Kg, 550℃ 2nd stage furnace → bottom stage furnace: 710Kg, 750℃ Also discharged from the bottom stage furnace 1 The amount and temperature of ash are 100Kg and 1500℃. Thus, temperature control at each stage is performed by cooling the gas outside the system. Further, the gas amount control at each stage is performed by adjusting the amount of extraction. In order to control the temperature in each of the above-mentioned stage furnaces, in the bottom stage furnace, the amount of coal charged is fed there.
This is done by adjusting the amount of O ₂ and the amount of steam, but in each of the upper stage furnaces 2 to 4, the conduit pipe 1
This can be done by controlling the temperature of the generated gas extracted at each of the steps 0 to 12, and can also be done by appropriately controlling the timing of cutting out the chire by the cutting rolls 14 to 16.
Further, the reason for providing the throat portions 5 to 7 is that the gas pressure is increased in each stage furnace, and that the cutting roll is provided to control the passage of solids such as chir. According to the coal carbonization method of the present invention, carbonization, fractional distillation, and gasification are performed simultaneously, high-calorie and low-calorie gases can be recovered as desired, and oil and tar can also be separated. Next, the components of the produced gas in the example at the positions indicated by arrows A, B, C ₁ , C ₂ and D in FIG. 1 are as shown in the following table.

[Table] As is clear from the above table, according to the coal carbonization gasification method of the present invention, tar is recovered by complete carbonization of the charged coal, and furthermore, the thermal efficiency is increased, the amount of tar by-products is increased, etc. It has been confirmed that these methods are effective for various purposes, such as recovering high-calorie gas or low-calorie gas depending on the situation.

[Brief explanation of the drawing]

FIG. 1 is a conceptual diagram of the present invention. 1-4... Stage furnace, 5-7... Throat part, 8...
...Coal charging inlet, 9...Oxygen/steam inlet, 10
~12...Conducting pipe, 13...Branch pipe, 14-16
... Cutting roll, 17 ... Ash discharge port.

Claims (1)

[Claims] 1. The uppermost stage of a vertical multi-stage shaft furnace, in which a throat part with a narrow inner diameter is provided in the middle of each stage furnace, and a cutting roll and a branch/conducting pipe for passing the generated gas are provided at the lower part of each furnace between each stage furnace. Coal is charged into the furnace, and the coal is carbonized by supplying oxygen and steam to the bottom stage, and produced gas is optionally extracted from the branch/conducting pipes of the top stage furnace or each intermediate stage furnace, and the temperature of each stage furnace is controlled. In controlling the amount of oxygen and steam supplied to the amount of coal charged, the bottom furnace
A coal carbonization gasification method using a vertical multi-stage shaft furnace, characterized in that the other stage furnaces control the temperature of the produced gas extracted and the timing of cutting out the chir with cutting rolls.