JPH1135958A - Manufacture of valuable material from low grade coal - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a valuable material from a low grade coal enabling an effective use of the low grade coal by efficiently recovering a valuable material contained in the low grade coal from the coal. SOLUTION: In a deashing/desulfurization device 1, a low grade coal 11 is deashed and desulfunized and a low pollution fuel 21 is obtd., a high ash/high sulfur and high water content residual coal 12 obtd. from the deashing/ desulfurization device 1 is controlled its water content in a moisture adjusting device 2, the water content controlled residual coal is supplied to a combustion/ slagging device 3 and it is combusted with pure oxygen 13 in the combustion/ slagging device 3 to obtain slag 22, its waste heat is recovered and electricity is generated at a steam power generating device 4, fry ash is recovered from the flue gas 14 produced from the combustion/slagging device 3, and elemental sulfur or sulfuric acid 24 is manufactured by supplying the flue gas contg. sulfur dioxide to an elemental sulfur or sulfuric acid manufacturing device 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a valuable material of low-quality coal for effectively utilizing low-quality coal having high ash content and high sulfur.

[0002]

2. Description of the Related Art Normally, coal grades are distinguished by the degree of carbonization. Coal utilization technology has evolved by grade based on coal grade. High-grade, high-quality coal is used as an energy source, coke raw material, chemical raw material, etc., and is now on the verge of depletion. There is no technology involved in changing coal usage to low quality coal. The reason for preventing the use of low quality coal is environmental pollution. If low-quality coal is easily used, environmental pollution will cause wrinkles and cause a lot of distortion.

[0003]

The use of coal must be switched from high quality coal to low quality coal. But,
In the case of technology using high quality coal as fuel, there are many problems in directly converting this technology to technology using low quality coal. Combustion of low quality coal requires an exhaust gas desulfurization unit. This is expensive to build. Without a desulfurizer, air pollution would result. However, the technology to directly burn low-quality coal may become obsolete if the exhaust gas desulfurization unit is awaited. Low-quality coal produces large amounts of coal ash when burned. Residues do not have sufficient treatment technology. Coal ash contains heavy metals and is difficult to discard. Moreover, the conventional demineralization apparatus aims at demineralization of high-grade coal and is not enough to actively desulfurize a large amount of ash. Eventually, it can be thrown away somewhere and cause environmental pollution there. There is a problem that low-quality coal may become a source of garbage in the world if left as is. Accordingly, an object of the present invention is to provide a method for producing valuable materials of low-quality coal, in which valuable materials contained in low-quality coal are effectively recovered from the inside thereof, and effective utilization of low-quality coal is achieved.

[0004]

The above object can be achieved by the following means. (1) A degassing / desulfurizing device, a moisture adjusting device, a combustion / slagging device, a unitary sulfur or sulfuric acid production device, and a steam power generation device utilizing waste heat from the combustion / slagging device. Demineralized and desulfurized low-quality coal is obtained with a demineralization and desulfurization unit to obtain low-pollution fuel, and high-ash, high-sulfur and high-water-content coal obtained from the demineralization and desulfurization unit is adjusted with a moisture control unit. Moisture is adjusted, and the residual coal whose moisture has been adjusted is supplied to a combustion and slagging device, which burns it with pure oxygen to obtain slag, recovers waste heat, and generates electricity using a steam power generator. , Low-quality characterized by recovering fly ash from the exhaust gas produced by the combustion and slagging apparatus and supplying the exhaust gas containing the sulfurous acid gas to the unitary sulfur or sulfuric acid production unit to produce the unitary sulfur or sulfuric acid Production of valuable charcoal.

(2) Ash of low-quality coal is 20.0 wt%
As described above, the method for producing valuable materials of low quality coal according to the above (1), wherein the sulfur content is 2.0 wt% or more. (3) The method for producing valuable resources according to the above (1) or (2), wherein a low-quality coal having a particle size of 50 mesh or less is used. (4) The water content of the residual coal is adjusted to a moisture content of 0.2 to 1.0 kg-w.
The method for producing valuable materials of low-quality coal according to any one of the above (1) to (3), wherein the method is performed by setting a target value to ater / kg-drycoal. (5) The method according to any one of (1) to (4) above, wherein the oxygen concentration of pure oxygen or oxygen-enriched air used in the combustion / slagging apparatus is 30.0 vol% or more. Production of valuable materials of low quality coal.

(6) The sulfur dioxide concentration in the exhaust gas discharged from the combustion / slagging apparatus is 4.0 to 20.0 vol% -dr.
y. The method for producing valuable materials of low quality coal according to any one of the above (1) to (5), wherein (7) Fly ash obtained by burning the high water content residue is supplied to a combustion and slagging apparatus, and the valuable coal of low quality coal described in any of (1) to (6) above is produced. Law. (8) To the exhaust gas emitted by the simple sulfur or sulfuric acid production equipment,
The method for producing valuable materials of low-quality coal according to any one of the above (1) to (7), wherein ammonium sulfate is produced by applying an electron beam method.

(9) Exhaust gas discharged from a simple sulfur or sulfuric acid producing apparatus, exhaust gas discharged when producing ammonium sulfate,
(8) The method for producing valuable materials of low-quality coal according to the above (8), wherein gypsum, calcium sulfite, and magnesium sulfite are produced by applying a limestone-gypsum method and a magnesium carbonate method. (10) The low-quality coal according to the above (9), wherein the gypsum obtained by the limestone-gypsum method or the magnesium carbonate method, calcium sulfite, magnesium sulfite and fluidized bed combustion ash are recycled to a combustion / slagging apparatus. Valuables production method. (11) The method for producing valuable resources of low-quality coal according to the above (8), wherein a part of the carbon dioxide gas contained in the exhaust gas discharged from the simple sulfur or sulfuric acid production device is recycled to the combustion / slag device.

[0008] It is preferable to carry out the treatment for obtaining valuable resources from low-quality coal having a high ash content and high sulfur at the mine head of coal mining. In addition, it is necessary that the technology for converting into valuable resources should be a technology that takes into account environmental pollution. It is necessary that the market size of the obtained valuables is enormous. In the present invention, the characteristics of low-quality coal with high ash content and high sulfur, and the conventional elemental technology have been improved, and the combination thereof has been intensively studied. In addition, the process system was examined. Efficiency, low environmental impact, cost-balanced in and output. In order to obtain a positive outlook, we aimed to obtain expensive valuable resources, manufacture electric power, and build a new process system from these viewpoints.

[0009] High quality coal with high ash and high sulfur is a valuable resource. It can be used as a low-pollution fuel, elemental sulfur, sulfuric acid, gypsum and aggregate raw materials. Therefore, in the present invention, the characteristics of low-quality coal with high ash content and high sulfur and the conventional elemental technology have been intensively studied. Low-quality coal is effective as a raw material for low-pollution fuels, elemental sulfur, sulfuric acid, ammonium sulfate, gypsum and aggregate. As a result of designing a process system for these productions, a new process system for producing electric power and valuables from low-quality coal was constructed.

[0010]

FIG. 1 is a block diagram showing an embodiment of the present invention.
However, the present invention is not limited to this content. FIG. 1 is a flowchart of the valuable resource manufacturing method. Production of valuable materials of low quality coal is performed in the first to fourth steps. The first step 1 is a deashing / desulfurization step. Here, low-pollution fuel 21 and residual coal 12 are obtained from low-quality coal 11.
1 kg of low-quality coal 11 having an ash content of 25 wt% and sulfur of 5 wt% is supplied to a deashing / desulfurizing device. Ash content 3.6wt%,
37. Low-pollution fuel 21 and valuable ash 37.
Residual coal 12 having 8 wt%, sulfur 23.0 wt%, and moisture 37.5 wt% is obtained.

The second step 2 is a moisture adjustment step. Moisture content
Water to 0.2-1.0kg-water / kg-drycoal
adjust. The third step 3 is a combustion / slag step. Power generation
Step 4 is attached. After adjusting the water content of the residual charcoal 12,
It burns with pure oxygen 13. Residue adjusted in step 2
The coal residue 12 is supplied to a combustion / slag apparatus, and
U. The required oxygen amount is 0.281kg and the purity is good at 30vol%
No. Composition of Exhaust Gas 14 Released in Combustion / Slag Process
Is CO_TwoIs 31.6 vol%, H_TwoO is 61.7vol%, O
_TwoIs 1.9vol%, SO _TwoIs 4.4 vol%. Combustion temperature
Is 1200 degrees. Heat recovery in combustion / slagging equipment
Has an inlet calorie of 1110 kcal and an outlet calorie of 518 kcal
Therefore, it is 593kcal. This heat
To make steam and generate electricity. Slag temperature is 1300 degrees
Heat balance by degree. The slag 22 obtained here is bone
It can be used as a material. Steam power generation process 4 is power 2
3 is manufactured.

The fourth step 5 is a sulfuric acid production step. An ammonium sulfate production process 6, a lime / gypsum method process 7, etc. are attached. Therefore, ammonium sulfate, gypsum, calcium sulfite and the like can be produced. From the exhaust gas 14 discharged from the third step 3, ash 15
And ash 15 are returned to the third step 3 which is a combustion / slag step. Exhaust gas 14 on a dry basis is C
O ₂ : 82.7 vol%, SO ₂ : 11.5 vol%, etc. The concentration of SO ₂ is high, and at this concentration, ordinary exhaust gas desulfurization equipment is difficult to use. Rather, here, sulfuric acid 24
It is technically better to produce. A technique for producing sulfuric acid by burning sulfur is applicable. In the case of the fourth step 5, since the SO ₂ has already been produced, the sulfur combustion step can be omitted unlike the ordinary sulfuric acid production step.

From the sulfuric acid producing apparatus, a low concentration SO ₂ -containing gas 17 of several thousands ppm or less is discharged. These gases include
If the electron beam method is applied, ammonium sulfate 2
5 can be manufactured. At that time, ammonia 18 is supplied. Carbon dioxide gas 26 is released. Instead of the electron beam method,
If the lime-gypsum method is applied, a lime / gypsum method step 7 is performed.
Gypsum and calcium sulfite 19 result. The generated gypsum and calcium sulfite 19 may be recycled to the combustion / slag process 3. In the combustion / slag apparatus, the high-temperature reaction of the pure oxygen 13 is decomposed in the furnace to generate CaO. The generated CaO lowers the melting point of the slag 22 and increases the production concentration of SO ₂ produced simultaneously by the combustion and slag apparatus, thereby making the production of sulfuric acid advantageous. In addition, the sulfur in the ash is also decomposed by the action of high temperature, and this becomes SO ₂ . Other sulfate-containing substances, such as fluidized bed coal combustion ash, have a similar effect. By recycling CO ₂ , C + CO ₂ → 2CO is obtained. However, this reaction is an endothermic reaction, and the furnace temperature control action and CO 2
It has the effect of lowering the melting point of ash. Further, CaSO ₄ is reductively decomposed to produce SO ₂ and CaO.

[0014]

According to the present invention, low-quality coal is deashed and desulfurized to obtain a low-pollution fuel, and the remaining components, that is, high-ash, high-sulfur, and high-moisture residue coal are subjected to moisture adjustment, Residual coal is burned with pure oxygen to generate electricity, and sulfuric acid is produced from sulfurous acid gas emitted from exhaust gas. Therefore, according to the present invention, valuable resources contained in low-quality coal can be effectively recovered from the inside thereof, and effective utilization of low-quality coal can be achieved. Low quality coal turns into valuable resources such as expensive low pollution fuels, sulfuric acid and aggregates. It also turns into electric energy. The market for these valuables is huge. According to this method, in terms of cost, in and output are almost balanced. Also effective in reducing environmental impact.

[Brief description of the drawings]

FIG. 1 is a flowchart of a valuable resource manufacturing method.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 1st process (decalcification / desulfurization process) 2 2nd process (moisture adjustment process) 3 3rd process (combustion / slag process) 4 Power generation process 5 4th process (sulfuric acid production process) 6 ammonium sulfate production process 7 lime / gypsum Process process 11 Low quality coal 12 Residual coal 13 Pure oxygen 14 Exhaust gas 15 Ash 16 Water 17 Low concentration SO ₂ containing gas 18 Ammonia 19 Gypsum / Calcium sulfite 21 Low pollution fuel 22 Slag 23 Electric power 24 Sulfuric acid 25 Ammonium sulfate 26 Carbon dioxide gas

Continued on the front page (72) Inventor Tadaaki Shimizu 2-4-30 Igarashi Higashi, Niigata City, Niigata Prefecture (72) Masahiko Matsukata 1-16-1306 Miyukicho, Tokorozawa City, Saitama Prefecture

Claims (11)

[Claims] 1. A steam power generation system comprising a deashing / desulfurizing device, a moisture adjusting device, a combustion / slagging device, and a unitary sulfur or sulfuric acid producing device, and further utilizing waste heat from the combustion / slagging device. A low-pollution fuel is obtained by deashing and desulfurizing low-quality coal with a deashing / desulfurizing unit, and moisture adjustment of high-ash, high-sulfur, and high-moisture residue coal obtained from the deashing / desulfurizing unit. The residual coal whose moisture has been adjusted by the device
The slag is supplied to the slagging unit, and the slag is burned with pure oxygen in the combustion and slagging unit to obtain slag.The waste heat is recovered and generated by the steam power generation unit. And recovering fly ash and supplying the flue gas containing the sulfurous acid gas to an apparatus for producing elemental sulfur or sulfuric acid to produce elemental sulfur or sulfuric acid. 2. The method of claim 1, wherein the low-quality coal contains at least 20.0% by weight of ash and at least 2.0% by weight of sulfur. 3. The method for producing valuable resources according to claim 1, wherein the low-quality coal has a particle size of 50 mesh or less. 4. The water content of the residual coal is adjusted to a water content of 0.2 to 0.2.
The method for producing valuable resources of low-quality coal according to any one of claims 1 to 3, wherein the method is performed by setting a target value to 1.0 kg-water / kg-drycoal. 5. The method according to claim 1, wherein the oxygen concentration of the pure oxygen or oxygen-enriched air used in the combustion / slagging apparatus is 30.0 vol% or more. Production method of valuable charcoal. 6. The method according to claim 1, wherein the sulfur dioxide concentration in the exhaust gas discharged from the combustion / slagging apparatus is 4.0 to 20.0 vol% -dry. Production method of valuable charcoal. 7. The method for producing valuable materials of low-quality coal according to claim 1, wherein the fly ash obtained by burning the high water content residue is supplied to a combustion / slagging apparatus. . 8. The valuable material of low quality coal according to claim 1, wherein an ammonium sulfate is produced by applying an electron beam method to an exhaust gas discharged from a simple sulfur or sulfuric acid producing apparatus. Manufacturing method. 9. The gypsum, calcium sulfite and magnesium sulfite produced by applying a limestone-gypsum method and a magnesium carbonate method to an exhaust gas discharged from a simple sulfur or sulfuric acid production apparatus. Production of valuable materials of low quality coal. 10. The low quality as claimed in claim 9, wherein the gypsum, calcium sulfite, magnesium sulfite and fluidized bed combustion ash obtained by the limestone-gypsum method or the magnesium carbonate method are recycled to a combustion and slagging apparatus. Production of valuable charcoal. 11. The production of a valuable material of low-quality coal according to claim 8, wherein a part of carbon dioxide contained in exhaust gas discharged from the unitary sulfur or sulfuric acid production unit is recycled to a combustion / slag unit. Law.