JPS5829994B2 - Coal gasification method and device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improvement in a gasifier that gasifies coal grains and steam by feeding them into a gasifier that stores a molten heat medium.

This method uses a high-temperature melting substance such as molten iron as a heat medium, immerses a blowing pipe in it, and blows coal grains into the molten iron with steam to gasify the coal particles. Regardless of the type of coal, it can be efficiently gasified. Although there are methods that have many advantages such as dust removal and desulfurization, their practical application has been hindered due to the durability of the material of the blowing tube.

In fact, it can withstand reducing molten iron with a high carbon content at high temperatures of 1,500 to 16,008 C, and at the same time is durable against highly corrosive molten slag containing a large amount of calcium oxide, and does not react with high-temperature steam. It is almost impossible to find a refractory material for blowpipe in existing materials that will not be attacked.

This invention was made to solve this problem,
The coal grain injection pipe and the steam injection pipe are separated, and the coal grain injection pipe is installed so that it is not exposed to steam,
Injection of coal particles is carried out by circulating the gas produced by gasification, and the pipe for blowing coal particles is made of high-temperature reducing atmosphere and is made of high-temperature molten slag and molten iron. The above-mentioned disadvantages are avoided by blowing the iron into the molten iron at a high flow rate from above the liquid surface without immersing it in the liquid.

The details of one embodiment of this invention will be described below with reference to the drawings.

The coal pulverized by a pulverizer (not shown) is calcium oxide (
Coal) is mixed and fed into the molten iron 3 in the furnace F through the blowing pipe 2 along with the produced gas by a known feeding device 1.

The coal powder injection pipe 2 is made of a ceramic material that can withstand the molten slag 4 and molten iron 3 in the furnace F even at high temperatures of 1,500 to 16,000 G, such as hot-pressed boron nitride.

In general, nitride-based refractories such as silicon nitride, aluminum nitride, and boron nitride are extremely stable in a reducing atmosphere, but are weakly hydrolyzed by water vapor and acids in an oxidizing atmosphere.

Therefore, as shown in the figure, the insertion wall F1 of the furnace F through which the blowing pipe 2 passes is extended to the surface of the slag 4 so that the steam from the steam blowing pipe 5 does not come into contact with it.

That is, as mentioned above, except for water vapor, the interior of this type of gasifier is a reducing atmosphere for both the molten iron and the produced gas, and boron nitride does not get wet with molten slag, so if only water vapor is avoided, a considerable amount of Durable.

In this way, the coal particles injected into the molten iron 3 undergo carbonization pyrolysis to generate high-calorie gas, and the fixed carbon in the coal is released into the molten iron 3.
However, it is converted into water gas by a water gas reaction caused by high-flow steam blown in from the steam blowing pipe 5 installed around the top of the furnace F.

The gas of about 1000℃ generated in this way is extracted from the outlet F.
2 and enters a cooler 6 where it is rapidly cooled to prevent carbon precipitation. In this step, moisture ammonia and dust are removed. The enthalpy is recovered in the next waste heat boiler 7, and then it is sent to the next step, that is, the gas purification device 8. sent to.

In fact, according to experiments, the ash content is 14.1%, the volatile content is 42.2%,
When bituminous coal with fixed carbon 37.5%, moisture 6.0%, and sulfur content 0.2% is gasified, H255.2% and CO35.7% are produced.
, Co23.7%, CH4,2%, C2H40,7%,
Approximately 1450 m"/t of crude gas of C2H65 is generated.

As is known from the gas composition, this gas is a reducing gas.

The water separated in the gas-liquid separator 7a in a part of the boiler 7 becomes a refrigerant in the cooler 6.

A slag removal means F3 is provided on the side of the furnace F.
It communicates with the inside through a communication hole 9, through which molten iron 3, slag 4, etc. can flow.

The means F3 is provided with take-out holes 10 and 11 which are vertically separated from each other, and the slag 4 having a small specific gravity is taken out from the upper take-out hole 10, and the molten iron 3 is taken out from the lower take-out hole 11. The increased amount of molten iron due to the iron content in the rock and slag due to the ash content in the six rocks are taken out.

12 is a combustion furnace, which is communicated with the furnace F through upper and lower passages 13 and 14.

By injecting air into the furnace 12, the carbon in the molten iron 8 is oxidized and burned, supplying heat from thermal decomposition in the furnace F.

According to the above-mentioned gasifier, the blowing pipe 2 is made of a nitride-based refractory, and furthermore, the outer periphery of the blowing pipe 2 is surrounded by the extension of the furnace wall of the furnace F to the inside of the slag 4. Further, since the steam is introduced into the furnace F through a separate blowing pipe 5, the blowing pipe 2 does not come into direct contact with the water vapor and has a long lifespan.

[Brief explanation of the drawing]

The drawing is a side view showing one embodiment of this invention. 1... Feeding device, 2... Coal blowing pipe,
3... Molten iron, 5... Steam blowing pipe,
F...Gasifier.

Claims (1)

[Claims] 1. A method for gasifying coal by feeding it into a furnace using a molten heat medium through a blowing pipe, characterized in that the inner and outer peripheries of the blowing pipe are kept in a non-oxidizing atmosphere. and
The gasification method. 2. To maintain a non-oxidizing atmosphere around the inner and outer peripheries of the blow pipe,
2. The gasification method according to claim 1, wherein the produced gas is a coal carrier gas, and the outer periphery of the blowing pipe is insulated from the oxidizing atmosphere in the furnace. 3. A coal blowing pipe made of a material resistant to high temperatures in a reducing atmosphere is provided in the gasifier that stores the molten heat medium so as to communicate between the coal feeding device and the molten heat medium of the gasifier, and At least the upper part of the coal injection pipe in the gasification furnace above the surface of the molten heat medium is insulated from the surrounding air in the gasification furnace by the extension of the furnace wall of the gasification furnace, and the steam injection pipe is separately connected to the gasification furnace. A coal gasifier that opens into the atmosphere inside the furnace. 4. The coal gasification device according to claim 3, wherein the carrier gas in the coal feeding device is produced gas in the gasification furnace. 5. The coal gasification apparatus according to claim 3, wherein the material of the blowing pipe is boron nitride.