JPH05320668A - Gasification of carbonaceous material - Google Patents

Abstract

PURPOSE:To decrease fluctuation in the consumption of the gases formed and prolong the life of the injection nozzle of a gasification burner or of the fire brick lined as the inner walls of a gasification furnace, used in the gasification reaction by partial oxidation of carbonaceous materials such as coal. CONSTITUTION:A process for gasifying carbonaceous material comprises injecting a water slurry containing particulate coal or petroleum coke or a residual oil at a high temperature through a gasification burner into a gasification furnace and simultaneously injecting thereinto oxygen at a high pressure through the gasification burner by means of a compressor, thereby subjecting the coal or the like to partial combustion to convert it into carbon monoxide and hydrogen, wherein the fluctuation of the injection pressure of the oxygen is controlled to be within 0.01 (1%) in terms of the ratio of pulsating amplitude pressure difference to average pressure.

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, more specifically, a water slurry containing fine coal or petroleum coke in a gasification furnace, or residual oil and oxygen at the same time. , A gasification method comprising partial combustion of carbonaceous raw material such as coal, petroleum coke or residual oil by converting the carbonaceous raw material into a carbon monoxide and hydrogen by jetting and burning from a gasification burner at high temperature and high pressure ..

[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 the water slurry and oxygen (or a gas containing oxygen) are simultaneously supplied from a gasification burner to a gasification furnace. At high temperatures (for example, 1350 to
(1500 ° C.), it is jetted at a high pressure to cause instantaneous combustion to partially burn the coal or petroleum coke and convert it into carbon monoxide and hydrogen, for example, a Texaco method. Known as the coal gasification process, etc., hydrogen gas produced by this coal gasification is reported as described in "Ammonia Production Plant by Coal Gasification" (published in "Chemical Equipment" January 1985 issue). It is actually used in 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 reduced pressure residual oil as a raw material. In this case, the residual oil is preheated to a high temperature, mixed with steam if necessary, and then supplied to the gasification burner.

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

[0004]

The above-mentioned coal or petroleum coke gasification method or petroleum residual oil gasification method (hereinafter sometimes collectively referred to as coal gasification method).
In the above, the condition for ejecting the water slurry of coal or petroleum fine particles and oxygen from the gasification burner or the condition for ejecting the residual oil is very important for promoting the gasification efficiently, and therefore the shape of the gasification burner is It is designed with the utmost care in regards to dimensions and materials. However, according to a study by the present inventor, even if a burner designed with such meticulous attention and installed is used and actual gasification is continuously carried out, the burner deteriorates with the passage of time, It was found that various problems such as destabilization of combustion state, fluctuation of composition of generated gas, and deterioration of refractory bricks on the inner wall of the gasifier occur.
Such problems reduce the advantages and evaluations of the gasification method used, and countermeasures for them are necessary.

That is, when the refractory bricks at the jet outlet of the gasification burner or the inner wall of the gasification furnace are deteriorated beyond the limit, it is necessary to replace or repair them.
This replacement or repair will incur the cost of the 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 low as possible.

[0006]

According to the present invention, in a gasification furnace, a water slurry containing fine-grained coal or petroleum coke or residual oil is heated at a high temperature from a gasification burner (sometimes called a process burner). A carbonaceous material formed by converting oxygen into carbon monoxide and hydrogen by ejecting high-pressure oxygen from the gasification burner at the same time as ejecting the gas, and partially burning coal, petroleum coke or residual oil. In the gasification method of the raw material, the fluctuation of the ejection pressure of oxygen is represented by pulsation amplitude pressure difference / average pressure within 0.01 (1%), preferably 0.005.
A method for gasifying a carbonaceous raw material is characterized by adjusting within (0.5%).

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

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

As described above, according to the present invention, when the high pressure oxygen is ejected from the gasification burner using the compressor, the fluctuation of the oxygen ejection pressure is represented by the pulsation amplitude pressure difference / average pressure of 1%. It is characterized in that it is adjusted to within (preferably within 0.5%). This pulsation amplitude pressure difference is a deviation from the average value (average pressure) of the pressure of oxygen (which may be a gas containing oxygen) sent to the gasification burner (the peak value of the pressure on the high side and the pressure on the low side). Value represented by the difference from the peak value of.

According to the study by the present inventor, as described above,
Various problems such as deterioration of burner that occurs over time, destabilization of combustion state, fluctuation of composition of generated gas, deterioration of refractory bricks on inner wall of gasification furnace are caused by ejection of oxygen from gasification burner. It was found that by suppressing the pressure fluctuation within the above range, the pressure was remarkably reduced. That is, by strictly restricting the fluctuation of the pressure of oxygen jetted from the gasification burner, the length of the flame generated at the jet outlet of the gasification burner by combustion of coal particles, petroleum coke particles or residual oil droplets can be made constant. Become. If the length of this flame becomes too large, the refractory bricks on the inner wall of the gasification furnace will deteriorate easily, whereas if the length of the flame becomes too short, the jet outlet (injection port) of the gasification burner Since the high temperature flame makes it easy to make contact, deterioration of the ejection port easily occurs in a short time. Further, when such deterioration of the gasification furnace or deterioration of the gasification burner occurs, the composition of the generated gas varies even when the gasification reaction is carried out using the same carbonaceous raw material under the same equipment and conditions. Easier to do,
Strict process control of the gasification reaction becomes difficult.

In the method for gasifying a carbonaceous raw material such as coal, petroleum coke or residual oil according to the present invention, the fluctuation of the oxygen injection pressure is adjusted by setting 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 arranged at an arbitrary position between the compressor 12 and the gasification burner 13 in the middle of the oxygen gas supply path 11. 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, the buffer tank uses the oxygen gas supply passage 21 in common when two compressors 22a and 22b and two gasification burners 23a and 23b are used. One on common path 21 (24)
You may arrange. 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 passage in order to remarkably reduce the fluctuation of the jet pressure of oxygen represented by the pulsation amplitude pressure difference / average pressure.

[0015]

EXAMPLE According to the gasification flow shown in FIG. 3, the gasification burner schematically shown in FIG. 4 was used, and the buffer tank was arranged at the position shown in FIG. 2 to gasify the residual oil as a carbonaceous raw material. The reaction was carried out continuously. Separately, for comparison,
The gasification reaction was continuously carried out under the same conditions except that no buffer tank was arranged. Then, the period up to the time (replacement time of the gasification burner) when a remarkable change in the produced gas composition occurs was examined. The results are shown below.
The number in 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 operating frequency Buffer tank used Buffer tank not used Approx. 7 Hz 0.0041 0.0166 (90 days) (10 days)

[0017]

EFFECTS OF THE INVENTION In a gasification method using a carbonaceous material such as coal or petroleum coke or residual oil as a raw material, fluctuations in oxygen ejection pressure according to the present invention are expressed as pulsation amplitude pressure difference / average pressure within 0.01. Adjusting to reduces the fluctuation of the flame length generated from the gas burner,
Deterioration of the gas burner and the gasification furnace is suppressed, and fluctuations in the composition of the generated gas are reduced.

[Brief description of drawings]

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

FIG. 2 is a flow chart showing another arrangement example of a buffer tank that is preferably used when implementing the method for gasifying a carbonaceous raw material of the present invention.

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

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

[Explanation of Codes] 11,21 Oxygen Gas Supply Channel 12,22a, 22b Compressor 13,23a, 23b Gasification Burner 14,24 Buffer Tank

Claims (2)

[Claims] 1. In a gasification furnace, water slurry or residual oil containing fine-grained coal or petroleum coke is jetted from a gasification burner at high temperature, and at the same time oxygen compressed to high pressure by using a compressor is supplied to the gas. In the gasification method of the carbonaceous raw material, which comprises the conversion from carbon monoxide and hydrogen by causing partial combustion of coal, petroleum coke, or residual oil by ejecting from a gasification burner, fluctuations in the ejection pressure of oxygen, A method for gasifying a carbonaceous raw material, characterized by adjusting the pulsation amplitude pressure difference / average pressure within 0.01. 2. The method for gasifying a carbonaceous raw material according to claim 1, wherein the adjustment of the fluctuation of the jetting pressure of oxygen is realized by providing a buffer tank between the compressor and the gasification burner.