KR102005903B1 - Additive composition for fouling, slagging and corrosion prevention of biomass co-existence or exclusive boiler using aluminum oxide - Google Patents

Abstract

The present invention relates to an additive composition for fouling, slagging and corrosion prevention of biomass fines or dedicated boilers using aluminum oxide, and more particularly, to an additive composition for fogging, slagging and corrosion prevention of boiler of a thermal power plant boiler by raising the melting temperature of an inorganic substance contained in biomass fuel The fouling of the biomass solu- tion or dedicated boiler using aluminum oxide which can effectively suppress the fouling, slagging and corrosion of the inner wall, optimize the thermal efficiency of the power plant, and further improve the efficiency of the industrial by- , Slagging and corrosion inhibiting additive compositions.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an additive composition for fouling, slagging and corrosion prevention of a biomass-containing or exclusive boiler using aluminum oxide, and more particularly to an additive composition for fogging, slagging and corrosion prevention,

The present invention relates to an additive composition for fouling, slagging and corrosion prevention of biomass solubles or dedicated boilers using aluminum oxide, and more particularly, to an additive composition for preventing fogging, slagging and corrosion of an exclusive boiler by using aluminum oxide contained in aluminum by- The present invention relates to an additive composition capable of effectively suppressing fouling, slagging and corrosion on the inner wall of a thermal power plant boiler and optimizing thermal efficiency of a power plant.

In 2012, the government is implementing a Renewable Energy Portfolio (RPS) system to reduce carbon dioxide emissions and expand the market for new and renewable energy and to enhance its competitiveness. And substitutes biomass for fuels such as cottons, or fulfills the obligation through coexistence.

Although biomass such as wood chips, wood pellets, and palm oil husks are in the spotlight as eco-friendly renewable energy in that they can reduce SO ₂ emissions due to the low sulfur content compared to existing fuels, Therefore, when biomass is mixed with existing fuel, local heat imbalance due to difference in calorific value is caused, thermal efficiency is decreased, and consequently, power generation cost is increased.

In addition, when biomass is lost, inorganic substances having a low melting point in the ash contained in the biomass are melted in the combustion process. Such inorganic substances flow to cause slagging and fouling phenomenon that grows on the inner wall of the boiler and heat exchanger, This phenomenon significantly reduces the heat efficiency of the boiler, interferes with the flow pattern in the combustion furnace, and furthermore causes a problem of seriously damaging the inner wall of the boiler.

In addition, the strong alkaline components such as K ₂ O and Na ₂ O contained in the biomass are highly volatile, so that the stay time in the boiler is short, which not only causes uneven combustion but also causes the inner wall to be coated There is also a problem that the metal surfaces including the inner wall of the boiler are corroded.

However, in spite of these problems, it is mandatory to use more than a certain percentage of new and renewable energy in the thermal power plant, and if it is not implemented, the power imposed on the power plant of several hundreds of millions will be imposed on the heat imbalance , Slagging, fouling and corrosion problems are urgently needed.

As a conventional technique for solving such a problem,

Korean Patent No. 10-1542076 entitled " Combustion Additive Composition of Solid Fuel and Method of Using the Same "discloses a combustion additive composition for a solid fuel comprising 100 parts by weight of water, 0.1 to 20 parts by weight of a copper precursor, and 10 to 300 parts by weight of a magnesium precursor Compositions are presented,

In Korean Patent No. 10-0642146 entitled " Fuel Additive Composition for Improving Cold Resistance and Preventing Slag and Effectively Removing Clinker ", 30 to 86.98% by weight of a water-soluble solvent, 5 to 20% by weight of a continuous accelerator, 0.01 to 5% by weight of a stabilizer, A fuel additive composition comprising 5 to 25% by weight of a metal compound, 0.01 to 5% by weight of a metal compound and 3 to 15% by weight of a surfactant compound,

Korean Patent No. 10-1586430 entitled " Fuel Additive Composition for Improving the Combustion Ratio of Pellets and Coal Fuel and Incineration Waste "discloses that 5 to 15 parts by weight of hydrogen peroxide, 30 to 45 parts by weight of sodium hydroxide, 1 to 10 parts by weight of oxygen, 10 to 50 parts by weight of oxygen, 2 to 5 parts by weight of glycerol, 1 to 3 parts by weight of a fatty acid ester, 2 to 5 parts by weight of a surfactant and 10 to 30 parts by weight of a ceramic ball .

However, all of the above-mentioned technologies have a problem in that workability is significantly lowered when they are added to a thermal power plant boiler as a liquid phase additive.

The present invention has been proposed in order to solve the above problems. It is an object of the present invention to effectively prevent fouling, slagging and corrosion on the inner wall of a thermal power plant boiler by raising the melting temperature of an inorganic material contained in biomass fuel using aluminum oxide, It is an object of the present invention to provide an additive composition for fouling, slagging and corrosion prevention of biomass or dedicated boiler using aluminum oxide which can not only optimize the thermal efficiency of power generating facilities but also increase the efficiency of industrial byproducts .

In order to solve the above-mentioned problems, an additive composition for fouling, slagging, and corrosion of a biomass solu- tion or dedicated boiler using aluminum oxide according to an embodiment of the present invention includes 100 parts by weight of fuel injected into a biomass- 0.01 to 1 part by weight of aluminum by-product containing aluminum oxide (Al ₂ O ₃ ) may be included.

Here, the aluminum by-product may be any one of calcined silica, aluminum dross, and refinery waste catalyst, or a mixture of two or more thereof.

일 수 있다.The particle size of the calcined silica, aluminum dross, and refined waste catalyst is 10 to 1500

Lt; / RTI >

The calcined silica may also be an industrial by-product of the aluminum smelting process.

The aluminum dross may be an oxide layer formed on the surface of the molten aluminum by dissolving aluminum metal or scrap.

In addition, the refined waste catalyst may be an industrial by-product in which the catalyst for fluid catalytic cracking (FCC) is decomposed due to a decrease in catalytic function due to the accumulation of vanadium and nickel on the surface of the zeolite during the cracking of heavy oil.

In addition, the aluminum by-products may have an aluminum oxide content of 10 to 90%.

Meanwhile, the additive composition for fouling, slagging, and corrosion of the biomass or proprietary boiler using aluminum oxide may further include 0.01 to 4 parts by weight of bottom ash, which is a by-product of a thermal power plant.

The additive composition for fouling, slagging and corrosion prevention of biomass or proprietary boiler using aluminum oxide according to an embodiment of the present invention increases the melting temperature of the inorganic material contained in the biomass fuel and increases the fouling of the inner wall of the thermal power plant boiler , It is possible to effectively suppress the slagging and corrosion and to optimize the thermal efficiency of the power generation facility and to improve the utilization of aluminum byproducts that have been treated by the conventional landfill, thereby providing not only an environmentally friendly solution but also an economic effect have.

1 is a graph showing changes in Al and K in bottom ash according to [Example 1] of the present invention.
2 is a graph showing Al and K fluctuations in fly ash according to Example 1 of the present invention.

Hereinafter, the description of the present invention with reference to the drawings is not limited to a specific embodiment, and various transformations can be applied and various embodiments can be made. It is to be understood that the following description covers all changes, equivalents, and alternatives falling within the spirit and scope of the present invention.

Furthermore, the singular expressions used in the present invention include plural expressions unless the context clearly indicates otherwise. It is also to be understood that the terms " comprising, "" comprising, "or" having ", and the like are intended to designate the presence of stated features, integers, And should not be construed to preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

In the following description of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Hereinafter, the composition of the additive for fouling, slagging, and corrosion of the biomass solu- tion or dedicated boiler using aluminum oxide according to an embodiment of the present invention will be described in detail.

The additive composition for fouling, slagging and corrosion prevention of a biomass disposal or a dedicated boiler using aluminum oxide according to an embodiment of the present invention is characterized in that, with respect to 100 parts by weight of fuel injected into a biomass combine boiler or a dedicated boiler of a thermal power plant, May be 0.01 to 1 part by weight.

Here, the aluminum by-product contains aluminum oxide (Al ₂ O ₃ ), and the content of aluminum oxide is preferably 10 to 90%.

In addition, the aluminum by-product may be any one of calcined silica, aluminum dross, refinery waste catalyst, or a mixture of two or more thereof. That is, the calcined silica, the aluminum dross, and the refined oil waste catalyst preferably have an aluminum oxide content of 10 to 90%, respectively.

This is because, when the aluminum oxide content is less than 10%, it is difficult to expect the effect as an additive for fouling, slagging and corrosion prevention, and if it exceeds 90%, the economical efficiency as an industrial by-product can be reduced.

일 수 있다. 이는, 알루미늄 부산물의 입도가 10

미만일 경우, 부유현상으로 인해 연소로내의 충분한 반응시간을 확보하지 못하여 보일러 싸이클론 후단으로 이송할 수가 있고, 입도가 1500

를 초과할 경우, 충분히 순환되지 못하여 파울링, 슬래깅 및 부식방지의 효과가 저감될 수 있기 때문이다.In addition, the calcined silica, aluminum dross, and refined waste catalyst have particle sizes of 10 to 1500

Lt; / RTI > This is because when the particle size of the aluminum byproduct is 10

, It is not possible to secure a sufficient reaction time in the furnace due to the floating phenomenon and it can be transferred to the end of the boiler cyclone, and when the particle size is 1500

The effect of the fouling, slagging and corrosion prevention can be reduced.

More specifically, calcined silica can be an industrial by-product of the aluminum smelting process.

The aluminum dross may be an oxide layer formed on the surface of the molten aluminum by dissolving aluminum metal or scrap.

In addition, the refined waste catalyst may be an industrial by-product in which the catalyst for fluid catalytic cracking (FCC) is decomposed due to a decrease in catalytic function due to accumulation of vanadium, nickel, etc. on the surface of the zeolite during the cracking process. At this time, it is preferable that the refinery waste catalyst is mainly composed of silicon dioxide and aluminum oxide, and the fouling, slagging and corrosion prevention effect can be reduced when aluminum oxide is not the main component.

Meanwhile, an additive composition for fouling, slagging, and corrosion of a biomass or proprietary boiler using aluminum oxide according to an embodiment of the present invention may further include 0.01 to 4 parts by weight of bottom ash, which is a by-product of a thermal power plant. That is, the bottom ash may include 0.01 to 4 parts by weight based on 100 parts by weight of the fuel to be fed into the biomass mixture or the dedicated boiler of the thermal power plant.

The bottom ash added to the fuel acts as a fluid medium to control the content of aluminum oxide, and specifically the content of aluminum oxide can be adjusted to about 25%. However, the above contents are illustrative and not restrictive.

When the amount of the bottom ash is less than 0.01 part by weight, it is difficult to expect a function as a fluidized medium. When the amount of the bottom ash exceeds 4 parts by weight, the aluminum oxide content of the additive composition may be lowered and fouling, slagging and corrosion prevention effect may be reduced.

Hereinafter, the principle of the composition for fouling, slagging and corrosion prevention of the biomass-mixed or exclusive boiler using aluminum oxide according to the embodiment of the present invention will be described in detail.

Generally, a biomass having a high content of Si and K and a low content of Ca has a low melting temperature. When Si is present in the form of SiO ₂ , the biomass has a relatively high melting temperature.

Herein, the strong alkali components such as K ₂ O and Na ₂ O contained in the biomass lower the melting point of the combustion furnace and improve the volatility. In particular, the melting point of an inorganic ash such as potassium oxide, The melting point is lowered to 800 ° C.

Accordingly, when the temperature in the furnace is formed at 800 ° C. or higher, the inorganic materials having a melting temperature of about 800 ° C. are melted and flowed while being adhered to the inner wall of the boiler and the heat exchange portion, and solidified Resulting in slagging and fouling.

Therefore, in order to solve this problem, in the present invention, the aluminum oxide contained in the aluminum by-products is injected into the combustion furnace to increase the melting temperature of the inorganic substances contained in the biomass to prevent the slagging and fouling phenomenon. The reaction formula is as follows.

(1) K ₂ O + Al ₂ O ₃ -> ₂ KAlO ₂ (raised to about 1000 ° C.)

(2) Na ₂ O + Al ₂ O ₃ -> ₂ NaAlO ₂ (raising to about 1200 ° C.)

Here, when the temperature in the furnace exceeds 1200 ° C, inorganic substances of K and Na series, which cause slagging and fouling, react with aluminum oxide and KAlO ₂ Or NaAlO ₂ , which can be discharged from the boiler in the form of fly ash and bottom ash to inhibit slagging and fouling in the furnace.

Bottom ash, which may be further included in the additive composition, is a substance that has already undergone a combustion process in a thermal power plant boiler and remains as a solid component without combustion when the additive composition burns and circulates with the ash. At this time, the circulating bottom ash exerts an effect of physically removing the existing clinker from the wall of the furnace, and it is not petrified when attached to the inner wall of the boiler, so that the clinker can be peeled from the inner wall.

On the other hand, when biomass is burned, the K component contained in the ash is burned and becomes an aerosol state in the form of KCl, which causes corrosion on the oxidized metal surface, which causes a problem of shortening the life of the power plant boiler remarkably. Accordingly, in the present invention, aluminum oxide is reacted with potassium chloride to inhibit metal surface corrosion in the boiler, and the reaction formula thereof is as follows.

(3) Al ₂ O ₃ XSiO ₂ + 2KCl + H ₂ O -> K ₂ OAl ₂ O ₃ XSiO ₂ + 2HCl

(4) 2KCl + H ₂ O + Al ₂ O ₃ -> 2KAlO ₂ + 2HCl

In the present invention, aluminum oxide reacts with potassium chloride and is discharged to the outside of the boiler in the form of fly ash and bottom ash, thereby suppressing corrosion of metal surfaces in the boiler.

Meanwhile, the additive composition for fouling, slagging and corrosion prevention of biomass solubles or dedicated boilers using aluminum oxide according to an embodiment of the present invention is characterized in that limestone (CaCO ₃ ) is added to petro coke used as a fuel of a circulating fluidized- And may further include industrial byproducts produced by charging.

Here, Petro coke is a by-product of refining oil refining in the refinery. It is a solid form carbide remaining after removing various oil. Such petro coke does not originally produce combustible material, but the removal of sulfur (S) Limestone (CaCO ₃ ) may be added to produce industrial by-products containing calcium oxide (CaO) and calcium sulfate (CaSO ₄ ) as main components.

The inclusion of industrial by-products resulting from the introduction of limestone into petro coke not only complements the low Ca content of the biomass but also contributes to the oxidation of minerals of the K and Na series, thereby increasing the melting point of the combustion furnace .

At this time, the industrial byproduct produced by adding the limestone to the petroleum coke may be 0.01 to 1 part by weight based on 100 parts by weight of the fuel, and when less than 0.01 is added, it is difficult to serve as an additive for preventing fouling and slagging, There is a problem that not only the calcium content is excessively increased but also the alkalinity of the K and Na series is excessively neutralized.

In addition, the composition for fouling, slagging, and corrosion prevention of biomass solubles or dedicated boilers using aluminum oxide according to an embodiment of the present invention is characterized in that in the smelting of aluminum, And may further include a red mud.

When the red mud is added to the biomass boiler as a residue containing a large amount of iron oxide, the red iron mordant iron is involved in the oxidizing action of the K and Na-based minerals, thereby increasing the melting point of the furnace Thus, slagging and fouling of the combustion furnace can be prevented.

In this case, the red mud is preferably added in an amount of 0.01 to 1 part by weight based on 100 parts by weight of the fuel, and when it is added in an amount of less than 0.01 part by weight, it can hardly be expected to serve as an additive for preventing fouling and slagging If the amount is more than 1 part by weight, there is a possibility that the oxidizing action is more actively performed than the reference value.

In addition, an additive composition for fouling, slagging, and corrosion of a biomass disposal or dedicated boiler using aluminum oxide according to an embodiment of the present invention may further include SAS (sodium aluminum sulfate).

Sodium Aluminum Sulfate (SAS) is an acidic by-product of the polysilicon manufacturing process and can act as an oxidizing agent to oxidize the K and Na-based inorganic materials of the biomass, thereby increasing the melting point of the oxide.

The SAS may be added in an amount of 0.01 to 1 part by weight based on 100 parts by weight of the fuel, and if it is added in an amount of less than 0.01 part by weight, it can hardly be expected to serve as an additive for preventing fouling and slagging. There is a possibility that the oxidizing action may be more actively performed than the reference value.

The additive composition for fouling, slagging and corrosion prevention of biomass disposal or exclusive boiler using aluminum oxide according to an embodiment of the present invention may further include the above industrial byproducts to enhance the efficiency of industrial byproducts, , Slagging and the like can be effectively prevented.

Hereinafter, embodiments of the additive composition for fouling, slagging and corrosion prevention of the biomass disposal or exclusive boiler using aluminum oxide according to the present invention will be described in more detail with reference to FIGS. 1 and 2, The present invention is not limited to these examples.

[Example 1]

(median 700

)의 하소실리카 9.1톤(연료 100중량부에 대하여 0.297 중량부)를 투입하여 5일간 일평균 22시간 가동하였다.In a circulating fluidized-bed thermal power plant boiler, a daily average of 919 tons of bituminous coal and 2,144 tons of wood pellets fuel, an aluminum content of 42.4% and a grain size of 300 to 1000

(median 700

) Of calcined silica (0.297 parts by weight based on 100 parts by weight of the fuel) were charged and operated for 5 days on average daily for 22 hours.

The elemental content and particle size distribution of the charged calcined silica are summarized in Table 1 and Table 2, and the potassium content in the bottom ash and fly ash for 5 days is summarized in FIG. 1 and FIG.

The calcined silica element content (wt%) of [Example 1] division Ca Mg Fe Si Al HA-01 ND ND 0.02 1.33 42.40

(%) Of calcined silica in [Example 1] division HA-01

<100

0 <300

0.05 <500

37.5 <1000

99.8 <2000

100 <3000

100

FIG. 1 is a graph showing changes in Al and K in bottom ash according to Example 1 of the present invention. FIG. 2 is a graph showing changes in Al and K in fly ash according to Example 1 of the present invention. to be.

Referring to FIGS. 1 and 2, it can be confirmed that the aluminum content and the potassium content in the ash have a quantitative proportional relationship. This means that sodium oxide contained in the calcined silica reacts with potassium chloride and discharged to the outside of the boiler in the form of bottom ash and fly ash. As a result of visually checking the slagging, fouling and corrosion phenomena in the boiler after the shutdown, Which shows a remarkable reduction effect compared with the input operation.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, You will understand. The embodiments described above are therefore to be considered in all respects as illustrative and not restrictive.

Claims (8)

0.01 to 1 part by weight of aluminum by-product containing aluminum oxide (Al ₂ O ₃ ), based on 100 parts by weight of the fuel injected into the biomass solu- tion or dedicated boiler,
Further comprising an industrial by-product formed by charging limestone (CaCO ₃ ) into petro coke,
Wherein the aluminum by-product is calcined silica,
The calcined silica has a particle size of 50 to 500

Wherein the additive composition for fogging, slagging, and corrosion of a biomass fountain or dedicated boiler using aluminum oxide is characterized in that the additive composition is an aluminum oxide.
delete delete The method according to claim 1,
The calcined silica may be,
Slagging and corrosion inhibiting additive composition of biomass solubilization or dedicated boiler using aluminum oxide characterized by being an industrial by-product of aluminum smelting process.
delete delete The method according to claim 1,
Wherein the aluminum byproduct has an aluminum oxide content of 10 to 90%. The additive composition for fouling, slagging and corrosion prevention of a biomass disposal or exclusive boiler using aluminum oxide.
The method according to claim 1,
Slagging and corrosion inhibiting compositions of biomass fines or dedicated boilers using aluminum oxide, further comprising 0.01 to 4 parts by weight of bottom ash which is a by-product of thermal power plants.

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