JP2614794B2 - Gasification method of carbonaceous raw material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for gasifying a carbonaceous raw material, and more particularly, to a method for simultaneously producing a water slurry or a residual oil containing particulate coal or petroleum coke and oxygen in a gasification furnace. A gasification method comprising jetting and burning from a gasification burner at high temperature and high pressure to partially burn carbonaceous materials such as coal, petroleum coke or residual oil to convert them into carbon monoxide and hydrogen. .

[0002]

2. Description of the Related Art Combustible fine particles obtained by finely pulverizing coal or petroleum coke are prepared into a water slurry, and this water slurry and oxygen (or a gas containing oxygen) are simultaneously supplied from a gasification burner to a gasification furnace. High temperature (for example, 1350-
A gasification method comprising jetting at a high pressure at 1500 ° C. and causing instantaneous combustion to partially burn the coal or petroleum coke to convert it into carbon monoxide and hydrogen is, for example, a Texaco method. Known as a coal gasification process and the like, and as reported in the “Ammonia Production Plant by Coal Gasification” (published in “Chemical Equipment” January 1985), hydrogen gas generated by this coal gasification is It is actually used for the production of ammonia as a raw material. The above coal gasification method is also applied to a gasification method using petroleum residual oil such as atmospheric residual oil or vacuum residual oil as a raw material. In this case, the residual oil is heated to a high temperature in advance, mixed with steam as needed, and then supplied to the gasification burner.

FIG. 3 shows an example of a specific flow sheet of the Texaco coal gasification process. That is, coal serving as a raw material for gasification is introduced into a mill (pulverizer) together with water and pulverized to form a coal / water slurry. This coal
The water slurry passes through a slurry tank and is sent to a gas burner of a gasification furnace by a slurry pump. On the other hand, oxygen is pressurized by a compressor and sent to the gas burner of the gasifier. The gas burner has a concentric injection port as shown in FIG. 4, for example. Coal / water slurry and oxygen are simultaneously injected from this injection port under high pressure and high temperature. And hydrogen and carbon monoxide are produced. The generated hydrogen and carbon monoxide are immediately cooled rapidly, and after separating unburned particles and ash generated at the same time, are sent to the next step as a fining gas and used as a raw material gas for various chemical industries.

[0004]

The above-mentioned gasification method of coal or petroleum coke or gasification method of petroleum residual oil (hereinafter sometimes collectively referred to as coal gasification method).
In the gasification burner, the conditions for ejecting water slurry and oxygen of coal or petroleum fine particles from the gasification burner or the conditions for ejecting residual oil are very important for efficient gasification, and therefore, the shape of the gasification burner Careful attention has been paid to dimensions, materials and the like. However, according to the study of the present inventor, even when using such a meticulously designed and installed burner, if gasification is actually continuously performed, the deterioration of the burner over time, It was found that various problems such as instability of the combustion state, variation in the composition of the generated gas, and deterioration of the refractory brick on the inner wall of the gasifier occurred.
Such a problem reduces the advantage and evaluation of the gasification method to be used, and its countermeasures are required.

[0005] That is, when the refractory bricks at the gas outlet of the gasification burner or the inner wall of the gasification furnace are deteriorated beyond the limit, they need to be replaced or repaired.
This replacement or repair involves the cost of new equipment and the cost of repair, and the gasifier must be shut down during the replacement or repair, and the frequency of such equipment replacement and repair. Should be as small as possible.

[0006]

SUMMARY OF THE INVENTION According to the present invention, a water slurry or residual oil containing fine coal or petroleum coke is heated at a high temperature in a gasification furnace from a gasification burner (also referred to as a process burner). Simultaneously with the jetting, a high-pressure oxygen is jetted from the gasification burner using a compressor to partially burn coal, petroleum coke or residual oil, thereby converting carbon monoxide and hydrogen to carbon monoxide. In the raw material gasification method, the fluctuation of the oxygen ejection pressure is expressed as a pulsation amplitude pressure difference / average pressure within 0.01 (1%), preferably 0.005.
(0.5%).

[0007] In the method for gasifying coal, petroleum coke or residual oil of the present invention, it is preferable to adjust the fluctuation of the oxygen injection pressure by providing a buffer tank between the compressor and the gasification burner.

Next, the present invention will be described in detail. The present invention
As described above, the present invention is an improvement of a gasification method of a carbonaceous material such as coal, petroleum coke or residual oil under high temperature and high pressure represented by the Texaco coal gasification process and the like, and an improvement of the gasification method used in the present invention. Various conditions already known for each of the method and the apparatus can be used. An example of the basic flow is shown in FIG. 3, but can be used in other flows.

According to the present invention, as described above, when oxygen having a high pressure is ejected from a gasification burner using a compressor, the variation of the oxygen ejection pressure is represented by a pulsation amplitude pressure difference / average pressure of 1%. Within (preferably within 0.5%). The pulsation amplitude pressure difference is defined as a deviation from the average value (average pressure) of the oxygen (which may be oxygen-containing gas) sent to the gasification burner (the peak value of the high side pressure and the low side pressure). Is the value represented by the difference from the peak value of

According to the study of the present inventors, as described above,
Various problems such as burner deterioration over time, unstable combustion conditions, fluctuations in the composition of the generated gas, and deterioration of the refractory brick on the inner wall of the gasification furnace are caused by the ejection of oxygen from the gasification burner. It has been found that suppressing the pressure fluctuation within the above range significantly reduces the pressure. In other words, by strictly restricting the fluctuation of the pressure at which oxygen is ejected from the gasification burner, the length of the flame generated at the gasification burner outlet by the combustion of the coal fine particles, petroleum coke fine particles, or residual oil fine droplets is constant. Become. If the length of the flame is too large, the refractory brick on the inner wall of the gasifier tends to deteriorate, while if the length of the flame is too short, the gasification burner outlet (injection port) is The high-temperature flame makes the contact easier, so that the deterioration of the ejection port easily occurs in a short time. In addition, when such gasification furnace deterioration or gasification burner deterioration occurs, the composition of the generated gas fluctuates even when the gasification reaction is performed using the same carbonaceous material and the same apparatus and conditions. Easier to do,
Strict process control of the gasification reaction becomes difficult.

In the gasification method for carbonaceous raw materials such as coal, petroleum coke or residual oil according to the present invention, the fluctuation of the oxygen injection pressure is adjusted by placing a buffer tank between the compressor and the gasification burner as described above. It is easily realized by providing.

For example, as shown in FIG. 1, an empty container 14 is disposed at an arbitrary position between the compressor 12 and the gasification burner 13 in the middle of the supply path 11 of the oxygen gas. It can be a buffer tank. The position and capacity of the buffer tank are determined in consideration of gasification conditions such as the supply amount of oxygen and the characteristics of the compressor.

As shown in FIG. 2, when two compressors 22a and 22b and two gasification burners 23a and 23b are used, the buffer tank has a common oxygen gas supply path 21, and One for common path 21 (24)
It may be arranged. In this case, the numbers of gasification burners and compressors can be arbitrarily selected.

A plurality of buffer tanks may be connected in series to the oxygen supply path in order to remarkably reduce the fluctuation of the oxygen ejection pressure represented by the pulsation amplitude pressure difference / average pressure.

[0015]

EXAMPLE According to the gasification flow shown in FIG. 3, the gasification burner shown schematically in FIG. 4 was used, and the buffer tank was arranged at the position shown in FIG. The reaction was performed continuously. Separately, for comparison,
The gasification reaction was continuously performed under the same conditions except that no buffer tank was provided. Then, a period up to a time when a remarkable change in the generated gas composition occurs (a time for replacing the gasification burner) was examined. The results are shown below.
The number in the parentheses indicates the number of days until a remarkable change in the generated gas composition occurs.

Fluctuation of oxygen ejection pressure (pulsation amplitude pressure difference / average pressure) Compressor operation frequency Buffer tank used Buffer tank not used About 7 Hz 0.0041 0.0166 (90 days) (10 days)

[0017]

According to the present invention, in a gasification method using a carbonaceous material such as coal or petroleum coke or residual oil as a raw material, the fluctuation of the oxygen ejection pressure is represented by a pulsation amplitude pressure difference / average pressure within 0.01. By adjusting to, the fluctuation of the flame length generated from the gas burner is reduced,
Deterioration of the gas burner and the gasifier is suppressed, and fluctuations in the composition of the generated gas are reduced.

[Brief description of the drawings]

FIG. 1 is a flow chart showing an example of the arrangement of buffer tanks that are preferably used when carrying out the gasification method of a carbonaceous raw material of the present invention.

FIG. 2 is a flow chart showing another example of the arrangement of a buffer tank preferably used for carrying out the gasification method of a carbonaceous raw material of the present invention.

FIG. 3 is a flowchart 2 showing an example of a flow of a known coal gasification process.

FIG. 4 is a schematic view showing an example of the structure of a gasification burner used in a known coal gasification process.

[Explanation of symbols]

 11, 21 Oxygen gas supply path 12, 22a, 22b Compressor 13, 23a, 23b Gasification burner 14, 24 Buffer tank

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C10J 3/72 C10J 3/72 J

Claims (2)

(57) [Claims] In a gasification furnace, a water slurry or a residual oil containing finely divided coal or petroleum coke is ejected from a gasification burner at a high temperature, and oxygen, which has been pressurized using a compressor, is supplied to the gas. In the method of gasifying a carbonaceous raw material, which is caused by jetting from a combustion burner and partially burning coal, petroleum coke or residual oil to convert it into carbon monoxide and hydrogen, A method for gasifying a carbonaceous raw material, wherein the method is adjusted to 0.01 or less as a pulsation amplitude pressure difference / average pressure. 2. The method for gasifying a carbonaceous raw material according to claim 1, wherein the adjustment of the fluctuation of the oxygen injection pressure is realized by providing a buffer tank between the compressor and the gasification burner.