JPS6071690A - Production of gas having low sulfur content by coal gasification - Google Patents

Abstract

PURPOSE:To obtain a coal gasification gas having low sulfur content, in high efficiency, at a low cost, by blasting converter dust, etc. into a coal gasification furnace, and contacting the gas with the dust particles at a specific temperature. CONSTITUTION:The objective gas is produced by introducing converter dust and/or electrical furnace dust composed mainly of iron (oxide) and having a particle diameter of <=10mum into a coal-gasification furnace and/or its product gas line, thereby contacting the gas with the dust at 400-800 deg.C. The amount of the dust introduced into the furnace, etc. is specified by the formula I and formula II[ X is S concentration (g/Ncm<3>) in the produced gas without introducing the dust; CFe is Fe-content of the dust (wt%); CS is S-content of the dust (wt%); YO is theoretically required amount of the dust (g/Nm<3>-produced gas); f is 1.2-3.5; Y is optimum amount of dust to be introduced into the furnace (g/Nm<3>-produced gas)].

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a method for obtaining a low sulfur-containing gas during coal gasification.

[Technical background of the invention and its problems]

Gasification of coal is being strongly promoted from the viewpoint of effective use of alternative energy to petroleum. In this case, a coal gasification process such as the Lurgi process or the Dinkler process is usually used.

However, in this type of process, much of the sulfur content in the coal is transferred to the produced gas (the main component is H2S), so in order to sell the produced gas as a tM product, the produced gas must be removed from the dust and sent to a desulfurization tower. I need to pass it.

Commonly used desulfurization methods include bakeem carboy and
These are wet methods such as Ito-eki, Silo, and Jis method. The principle of the wet method is to release the produced gas into the absorption liquid and remove the sulfur content (mainly Hz S ) in the gas. However, such a desulfurization method requires the installation of a special desulfurization tower and the necessity of cooling the produced gas to below 200°C, which increases equipment and operating costs. There is also a method of desulfurization using a desulfurization tower filled with limestone, as shown in the Guibelb face-to-face reduction process, but this requires the use of lumpy limestone and is inevitably expensive.

On the other hand, although converter dust and electric furnace dust are used as raw materials for blast furnace dust pellets after recovery, it is difficult to say that they are fully utilized. - and electric furnace dust, as shown in Table 1, are fine powders containing iron cylinders or their oxides as a main component and having a particle size of 10 μm or less.

Table 1 [Object of the Invention] In view of the fact that, as mentioned above, in the conventional method (r), desulfurization was carried out in a desulfurization tower, which resulted in poor adjacency,
Fortunately, converter dust and electric furnace dust are similar and contain iron, so when the dust comes into contact with gas, the sulfur in the gas reacts with the iron in the dust to form iron sulfide, which is effective. This method takes advantage of the fact that the sulfur content is removed from the furnace and the single-core speed is high, eliminating the need for a special desulfurization process and making it possible to effectively utilize converter and electric furnace dust. The purpose is to provide a method for producing gas.

[Structure of the invention]

This purpose is achieved by injecting converter dust and/or electric furnace dust into the coal gasifier and/or its produced gas conduit, and bringing the gas and dust particles into contact at a temperature range of 400 to 800°C. Achieved.

[Specific examples of the invention]

An example of the present invention is shown in Figs. 1 and 2. Fig. 1 shows a case where converter or electric furnace dust 2 is injected into a coal gasifier 1, and Fig. 2 shows a case where dust is removed from a coal gasifier 1. In the case where the dust 2 is blown into the generated gas conduit 4 to the dust 2, in any case, the gas and the dust 2 are brought into contact in a temperature range of 400 to 800 ° C. where the generated gas reaches the dust remover 3. The finally obtained low-sulfur-containing coal gasification gas is stored in the gas holder 5 and distributed at the same place where it will be used.

When injecting dust 2, in the case of Fig. 1, one or more tuyeres or nozzles are installed at appropriate locations in the coal gasifier 1, or the existing oxygen, air, or water vapor is injected. Blow through the chamber using a tuyere or nozzle.

Further, when the coal gasifier uses pulverized coal as a raw material, such as a fluidized bed or spouted bed type, dust is mixed with the pulverized coal in advance and blown into the coal. In the case of FIG. 2, the product gas conduit 4 is provided with one or more blowing nozzles at appropriate locations, through which the blowing is carried out.

Thus, blowing! Diluted converter dust and electric furnace dust are removed by the general purpose dust remover 3 by the generated gas without accumulating in the coal gasification furnace or the generated gas conduit.

In other words, the produced gas passes through the coal gasifier and the produced gas conduit until it reaches the dust remover. Either the reaction in which the sulfur content (mainly H2S) in the generated gas reacts with the iron content in the dust to produce iron sulfide, or the reaction rate is sufficiently fast because the dust D particles are small, so it must be carried out quickly. , As a result, low sulfur content coal gas can be obtained.

In the figure, the reaction in the case of sulfide water migration is shown as the sulfur content in the produced gas.

F e20wl (S)l-3I(2(g)=2F
e(S)+ 3 Hz O(g)B' ez 03(S
)+3CO(,g)-2Fe(S)+3CO2(
g) Fe304 (S)+4H2(g)”3Fe(S)
! -4Hz O(g)F' e304 (S)+4 C
o(g)=3 Fe(S)+4 CO2(ωFe
0(SH-ru(g)=Fe(August-II20tg)F
e0(S)+CO(g)-Fe(S)+CO2C0
2(e(S)4-Eb S(g)=F e 5(s)
+Hi+ (g) In the present invention, as the blown dust, not only converter dust or electric furnace dust alone, but also a mixture of both can be used. As in the examples described later, there is almost no difference in effectiveness depending on the type of dust. Further, the injection point may be both inside the coal gasifier and in the four produced gas pipes.

However, the contact temperature range between the generated gas and dust is 400 to 8
It is preferable to set the temperature to 00'C, and as shown in the examples below, at temperatures below 400°C, the reaction is almost complete; on the other hand, at temperatures above 800°C, the H2S concentration is not sufficiently reduced. Further, the amount of dust blown is given by the following equation [it is preferable to do it directly].

Y=fXY.

55.85 32-06 Where, t Ll)) YO: Theoretically required amount of dust (g/N+f-generated gas) f: Coefficient (f-1, 2~
35) Y: Appropriate dust injection i (g/Nrrt-generated gas)
If the dust blowing rate is less than the appropriate dust blowing rate given by the above equation, the sulfur content in the generated gas will not be removed sufficiently.

Furthermore, even if more than the appropriate amount is blown, there is no effect on reducing the SJ and degree in the generated gas, and it only increases the load on the blowing device and dust remover.

〔Example〕

In order to confirm the effects of the present invention, a trial was conducted using a coal gasification apparatus with a coal processing capacity of approximately 6 tons/B scale as shown in FIG.

Coke 7 was charged into the furnace through a bell 6, and dust was blown into the furnace together with pulverized coal, oxygen, and steam (the blown material is shown as 2').

The composition of pulverized coal and coke is shown in Table 2, and the dust is shown in Table 1.
．． It was set as 9. In addition, the code|symbol 8 in FIG. 3 is a sludge drainage hole.

In this way, the gas produced during gasification was obtained at a temperature of about 1000°C. In addition, we installed temperature-separated points at 8 points along the produced gas conduit 4, which has a total length of approximately 20 m, and used a stainless steel water-cooled sampling glove with a dust filter at the tip for zero sampling. , the sampled gas is continuously C05H2
, C02 and H2S were analyzed.

Experimental results f: Shown in Table 3.

The temperature in the above table is the average temperature of the gas at the Onana sampling point, and the H2S concentration is the H2S concentration in the gas at each sampling point.
The average concentration of

In addition, in all cases, the average composition of the generated gas is 68%C.
As can be seen from the results in Table 3, the H2S concentration when no dust was injected was 2800 pprn on average, and the change at each sampling point was large. However, it has been found that injecting converter dust and electric furnace dust has a large effect on the deterioration of H2S quality. It can also be seen that the reaction does not proceed at temperatures below 400'C at the sampling point, and that there is no sufficient effect in removing H2S at temperatures above 800C.

[Effects of the Invention] As described above, according to the present invention, the sulfur content in the generated gas can be removed as iron by reacting with the iron content in the dust, and the removal efficiency is also high. This eliminates the need to install a desulfurization tower, reduces construction costs and operating costs, and allows for effective use of converter/electric furnace dust.

[Brief explanation of drawings]

FIGS. 1 and 2 are conceptual diagrams of the method of the present invention, and FIG. 3 is a schematic diagram of the gasification equipment that was the subject of the experiment. 1. Coal gasifier 2. Dust 2'. Blowing material 3. Dust remover 4. Produced gas conduit 5. Gas holder patent applicant
Sumitomo Metal Industries Co., Ltd.

Claims (1)

[Claims] (1) Converter dust and/or electric furnace dust is injected into the coal gasifier and/or its produced gas conduit, and the gas and dust particles are brought into contact in a temperature range of 400 to 800°C. A method for producing low sulfur-containing coal gasification gas.