KR20220009670A - Additive composition for improving pollutants in solid refused fuel - Google Patents

Abstract

The present invention relates to an additive composition for improving solid waste fuel pollutants. When the additive composition of the present invention is added to solid waste fuel, the present invention can effectively reduce and prevent flow disturbance, efficiency reduction and temperature reduction of combustion equipment, corrosion and damage to equipment, lack of a stable operation member, low efficiency, high temperature corrosion, and the like. In particular, when the additive composition of the present invention is used, the present invention can prevent clinker from becoming larger and stronger due to frequent detachment of the clinker during operation of a boiler, and facilitates the detachment and removal of the clinker by weakening the strength of the clinker, thereby improving the risk of a working environment.

Description

Additive composition for improving pollutants in solid refused fuel

The present invention relates to an additive composition for improving solid waste fuel contaminants.

상승하였으며, 이로 인해 극지방과 고산지대의 빙하는 감소하고 겨울은 짧아졌다. 특히, 최근 들어 집중호우나 폭설, 폭염 등의 극한 기상이변 또한 자주 발생하고 있는 실정이다.Currently, due to the rapid increase in the use of fossil fuels, anthropogenic carbon dioxide (CO ₂ ) emissions are increasing significantly. This is emerging as a big problem in the international community. Carbon dioxide (CO ₂ ) emitted in large quantities remains in the atmosphere without being purified, and as it amplifies the greenhouse effect, it accelerates the global warming phenomenon. Due to global warming, the average global temperature in the 20th century was about 0.6

As a result, glaciers in the polar and alpine regions decreased and winters were shortened. In particular, in recent years, extreme extreme weather events such as torrential rain, heavy snow, and heat waves are also occurring frequently.

Therefore, in order to cope with rapid climate change and achieve the goal of low-carbon green growth, the development and supply of eco-friendly alternative energy sources are required. In recent years, solid waste fuel (SRF: Solid Refused Fuel, Bio- SRF, shaped or unshaped) are attracting attention as an alternative fuel.

Solid waste fuel refers to a solid fuel manufactured by sorting and separating combustible waste generated from workplaces and household waste, and then crushing, drying, compressing, and optionally forming it. These solid fuels have a high calorific value and are not only inexpensive because wastes are recycled as fuels, but also have various advantages such as economic benefits from recycling of waste resources and no need for separate safety facilities in storage facilities, so they are widely supplied.

However, the solid waste fuel using waste as a raw material may contain harmful substances. Among the waste components, PVC (Poly Vinyl Chloride) of waste plastic may be mixed, and these impurities become one of the causes of increasing the Na, K, and Cl content in the solid waste fuel. In addition, when waste plastics are taken from household waste, there is a possibility that hazardous components such as mercury, lead, and bromine may be mixed into the solid fuel. These solid waste fuels generate hazardous pollutants during or after combustion. For example, HCl generated during combustion is an acid gas that is not only corrosive and harmful to the gas itself, but is also a precursor to dioxine, a first-class carcinogen. do.

In addition, as described above, the solid waste fuel has a very high content of alkali metals such as Na and K, and reacts with _{chlorine (Cl) or sulfur trioxide (SO 3 ) in a high-temperature combustion process to KCl, K 2} SO ₄ , NaCl, Alkali metal compounds such as Na ₂ SO _{4 are produced.} The produced alkali metal compound has very strong adhesion properties in a certain temperature range. Therefore, when used as a fuel for a combustion facility, it is attached to the water pipe of the superheater or economizer provided in the combustion facility to form clinker, and this clinker causes slagging or fouling. make it In addition, since the combustion engine has an external sealing structure, it is difficult to detect the clinker formed therein, and it is difficult to remove the clinker during operation of the combustion facility.

Therefore, there is an urgent need to develop an additive for solid waste fuel that can solve and prevent various problems when the solid waste fuel is burned.

Domestic Registered Patent No. 10-1696398

The present inventors have completed the present invention to develop an additive composition for solid waste fuel that can solve/prevent flow disturbance, efficiency reduction and temperature reduction, corrosion and damage of equipment, stable operation member and low efficiency, and high temperature corrosion. .

Accordingly, an object of the present invention is borax (Borax); polyhydric alcohol; and a solvent; to provide an additive composition for improving contaminants of solid waste fuel, including a.

The present inventors have developed an additive composition for solid waste fuel capable of solving/preventing flow disturbance, efficiency reduction and temperature reduction, corrosion and damage of equipment, lack of stable operation and low efficiency, and high temperature corrosion.

Terms used in this document are only used to describe specific embodiments, and may not be intended to limit the scope of other embodiments. The singular expression may include the plural expression unless the context clearly dictates otherwise. Terms used herein, including technical or scientific terms, may have the same meanings as commonly understood by one of ordinary skill in the art described in this document. Among the terms used in this document, terms defined in a general dictionary may be interpreted with the same or similar meaning as the meaning in the context of the related art, and unless explicitly defined in this document, have an ideal or excessively formal meaning. not interpreted In some cases, even terms defined in this document cannot be construed to exclude embodiments of the present document.

In addition, each step of the process according to the present invention is not limited to being in a complete time-series sequence, and the invention is described in an easy-to-understand order according to the order applied to the general medium-density fiberboard manufacturing process, and the process sequence of the invention is Of course, it is possible to change or modify it as needed, and the preparation of the compositions to be described later may be performed separately as an individual process.

Hereinafter, the present invention will be described in more detail.

One aspect of the present invention is borax (Borax); sodium hydroxide; potassium hydroxide; polyhydric alcohol; And a solvent; to a solid waste fuel (Solid Refused Fuel) to an additive composition for improving contaminants comprising a.

In the present invention, "contaminant" includes hazardous components such as mercury, lead, and bromine that may be generated when using solid waste fuel, hazardous gases such as HCl, and clinker generated by combustion of solid waste fuel.

The clinker is a lump of ash made by combustion, and in the case of a process of burning coal, it refers to a material formed by melting and hardening ash contained in coal by heat.

In the present invention, "improving contaminants" refers to a decrease in clinker generation index (Clinker Index) and/or K ₂ O index (K _{2 O Index) after use of the composition compared to before use.}

The borax increases the combustion temperature to minimize unburned substances and promotes combustion by releasing oxygen to help combustion, and also to remove sulfur generated during combustion through alkali ions.

The borax may be included in an amount of 1 wt% to 15 wt% based on the total weight of the additive composition.

On the other hand, the additive composition of the present invention preferably contains 0.1% to 0.5% by weight relative to 100% by weight of the solid waste fuel, so when the borax is included in an amount of less than 1% by weight, the actually injected borax content is very small, so there is no effect There is a problem that cannot be expressed. In addition, when the borax is included in an amount of more than 15% by weight, due to the ash melting point reduction effect of borax, there is a problem that low-melting-point materials may be rapidly generated (see US 4057398).

The sodium hydroxide promotes combustion, reduces the internal atmosphere during combustion, delays the oxidizing atmosphere in the initial stage of the combustion flame, suppresses the rapid generation of CO in the early stage of combustion, and thereby promotes complete combustion.

The sodium hydroxide may be included in an amount of 1 wt% to 5 wt% based on the total weight of the additive composition. When the sodium hydroxide is included in an amount of less than 1% by weight, there is a problem that the effect is insufficient. In addition, when the sodium hydroxide is included in more than 5% by weight, there is a problem that the clinker generation tendency may increase.

The potassium hydroxide promotes combustion, reduces the internal atmosphere during combustion, delays the oxidizing atmosphere in the initial stage of the combustion flame, suppresses the rapid generation of CO in the early stage of combustion, and thereby promotes complete combustion.

The potassium hydroxide may be included in an amount of 1 wt% to 5 wt% based on the total weight of the additive composition. When the potassium hydroxide is included in an amount of less than 1% by weight, there is a problem that the effect is insufficient. In addition, when the potassium hydroxide is included in an amount of more than 5% by weight, the clinker index increases, there is a problem in that the clinker generation tendency may increase.

The polyhydric alcohol may include glycerin and/or ethylene glycol.

In order to allow the additive composition to be uniformly dispersed in water, a polyhydric alcohol may be used as the water-soluble dispersant as described above. In this case, the content of the water-soluble dispersant may be used within a range showing an effect of improving dispersion uniformity and within a range that does not affect changes in physical properties of the composition.

As the solvent, water may be used from the viewpoint of cost and dispersibility.

In this case, the content of the solvent may be used within a range showing an effect of improving dispersion uniformity and within a range that does not affect changes in physical properties of the composition.

The additive composition according to an embodiment of the present invention may further include a metal-based silicate compound.

In addition, the additive composition according to an embodiment of the present invention may optionally further include citric acid.

The metal-based silicate compound may include sodium silicate and/or calcium metasilicate.

The sodium silicate is crystalline, can soften hard water, and may contain modified substances referred to as α, β, γ and δ phases.

The calcium metasilicate has an aspect ratio (average major axial diameter/average minor axialdiameter) of 0.5:1 to about 2.0:1 and an oil absorption of about 10ml/100g to about 300ml /100 g.

The calcium metasilicate may have an improved disintegration ability due to the oil absorption rate and low aspect ratio in the above-described range. A high oil absorption rate means that calcium metasilicate can absorb a large amount of water, and a low aspect ratio means that calcium metasilicate has a high intraparticle pore volume. Accordingly, a solvent such as water may be absorbed by the calcium metasilicate and penetrate into the pores of the particles to inhibit the formation of clinker.

The metal-based silicate compound may be used when the Si component of the contaminant in the solid waste fuel is small (less than 30%).

The metal-based silicate compound may be included in an amount of 1 wt% to 20 wt% based on the total weight of the additive composition.

In the present invention, the additive composition may be used in a dispersed form by being injected into the solid fuel. This is to ensure that a large area can be uniformly dispersed even in a small amount and can be effectively burned in the combustion chamber.

According to one embodiment, for the above effect, the additive composition may have a liquid form.

On the other hand, the components that most affect the generation of clinker, a combustion impediment material in the solid waste fuel, are potassium and chlorine components contained in the fuel. Potassium and chlorine attach to the water pipe in the high temperature zone and cause continuous corrosion by chlorine, so a solution is needed. In particular, large thermal power plants are trying to reduce this phenomenon by using a mixture of solid waste fuel (especially bio) and coal. This is because the sulfur component contained in the coal inhibits the reaction caused by potassium chloride combined with potassium and chlorine.

KCl + SO ₃ (g) + H ₂ O -> K ₂ SO ₄ (g) + 2HCl (g)

However, when using the additive composition of the present invention, it is possible to obtain the above-described effects without a separate coal.

In order to obtain this effect, it is preferable that the additive composition of the present invention contains 0.1 wt% to 0.5 wt% based on 100 wt% of the solid waste fuel.

In addition, in the use of solid waste fuel, as another method for conventional clinker and fouling problems, a method of adding magnesium oxide and copper or a silicic acid-based high melting point and strong expansive mixture is used.

의 고온에서 장시간 지속되면 오히려 클링커을 유발하는 부작용이 생길 수 있는 문제점이 있다.However, when controlling mainly using only magnesium and copper as in the prior art, it is difficult to overcome the quantitative limit in increasing the melting point of ash or inducing expandability.

If it continues for a long time at a high temperature, there is a problem that can cause side effects that cause clinker.

Furthermore, in the use of solid waste fuel, it is known that hydrogen peroxide generates oxygen necessary for combustion when inputted, but in fact, all of it is vaporized during the heating process during the process from the additive input facility to the combustion chamber, and the effect on actual combustion There is no influence, but rather there is a problem of equipment corrosion. In addition, when hydrogen peroxide is added, it is difficult to store, and there is a problem of precipitation and precipitation when a certain period of time passes.

Accordingly, it is preferable that the additive composition of the present invention does not contain hydrogen peroxide.

The present invention relates to an additive composition for improving solid waste fuel pollutants, and when the additive composition of the present invention is added to solid waste fuel, flow disturbance, efficiency reduction and temperature reduction of combustion equipment, corrosion and damage of equipment, and stable operation It is possible to effectively reduce and prevent member, low efficiency, high temperature corrosion, and the like. In particular, when the additive composition of the present invention is used, it is possible to prevent clinker from becoming larger and stronger due to frequent dropping of clinker during boiler operation, and by weakening the strength of clinker to facilitate the dropping and removal of clinker, thereby improving the risk of the working environment. can do it

1A is a photograph of an inner wall of a combustion facility in which combustion has been performed using a composition according to an embodiment of the present invention.
1b is a photograph of the inner wall of a combustion facility in which combustion has progressed using a composition according to a comparative example of the present invention.
2 shows the results of a drop collision test for clinker produced before/after using the composition according to an embodiment of the present invention.
3 shows the clinker tendency and component analysis results for clinker produced before/after using the composition according to an embodiment of the present invention.
4 shows the results of visual comparison of clinker produced before/after using the composition according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail through examples. These examples are only for illustrating the present invention in more detail, and it will be apparent to those of ordinary skill in the art that the scope of the present invention is not limited by these examples according to the gist of the present invention. .

Example. Preparation of additive composition for improving solid waste fuel pollutants of the present invention

According to the content ratio of Table 1 below, the additive composition for improving solid waste fuel contaminants of the present invention was prepared.

First, sodium hydroxide and potassium hydroxide were dissolved in water, and borax was added thereto, followed by stirring. After the lysate was cooled to room temperature, glycerin and triethanolamine (TEA) were added thereto, followed by stirring. [Manufacturing conditions: 1L, stirrer: based on 6000rpm]

On the other hand, by analyzing the components of the contaminants, when the Si component is small (less than 30%), 10% of sodium silicate was replaced with 10% of water.

substance name Mass ratio (%) borax 10.000 sodium hydroxide 3.333 potassium hydroxide 1.667 glycerin 0.333 Triethanolamine (TEA) 0.333 water 84.33

comparative example. Preparation of additive composition for improving solid waste fuel pollutants according to some component changes

An additive composition for improving solid waste fuel contaminants was prepared in the same manner as in Example according to the content ratio shown in Table 1, except that borax was changed to magnesium, aluminum and calcium.

Experimental Example 1. Confirmation of clinker generation

1 A T/H class combustion system was prepared, and as a commercially available solid waste fuel, a combustible solid fuel of 4,000 kcal or more was prepared. Additives of Examples and Comparative Examples were added in a ratio of 800:1 of the solid waste fuel input amount (usage amount). Then, the combustion system was operated for 10 minutes under the same load factor of 85%. After combustion was completed, 100 mg each of Bottom-Ash and Fly-ash samples were collected from the fuel system.

Immediately after the combustion of the combustion system was completed, the pipe was visually observed, and the results are shown in FIG. 1 ( FIG. 1A : Example, FIG. 1B : Comparative Example).

In addition, after analyzing the index for the ash component collected from the Examples and Comparative Examples and showing the results in Tables 2 and 3, respectively, the clinker generation index (Clinker Index) was calculated based on Equation 1 below.

comparative example ingredient COAL FLY-ASH BOTTOM-ASH Clinker Index Ca 21.12 24.92 28.39 0.521565632 Si 35.84 39.55 27.28 Fe 12.21 12.55 21.03 Al 17.74 16.78 10.78 Mg - - 6.6 K 3.65 2.97 2.76 Ti 1.7 1.44 1.42 S 5.43 1.42 1.01 K ₂ O Index Mn - 0.32 0.41 7.19% Cu - - 0.31 Cl 2.31 - - V - - - Cr - - - Zn - - -

Example ingredient COAL FLY-ASH BOTTOM-ASH Clinker Index Ca 37.52 21.2 34.66 0.407524508 Si 27.58 41.02 16.73 Fe 18.51 10.13 28.25 Al - 19.03 6.96 Mg - 3.2 7.5 K 5.25 2.85 1.84 Ti 3.02 1.11 1.67 S 5.37 1.13 1.35 K ₂ O Index Mn - 0.26 0.75 6.90% Cu - 0.02 0.23 Cl 2.73 - - V - - 0.1 Cr - 0.02 - Zn - 0.03 -

As can be seen in FIGS. 1A and 1B , in the case of the example of the present invention, the clinker was removed, but in the case of the comparative example, it was found that the clinker was attached to the burner pit.

In addition, as can be seen in Tables 2 and 3, in the case of the Examples of the present invention, the clinker production index was 0.41, which decreased by about 21.1% compared to the comparative example (0.52), and the clinker production index was good, and the K ₂ O index (K Index ₂ O), it was found that in Figure 6.9, preferably made as compared with the comparative example (7.19).

Experimental Example 2. Produced clinker test

Based on the results of Experimental Example 1, the following experiments were additionally performed with respect to the additive composition for improving solid waste fuel contaminants in Examples of the present invention.

Prepare the injection and control system of the additive composition of the present invention in an industrial facility operating a 20T/H class fluidized bed incineration boiler, and use a combustion system for solid fuel (combustible solid fuel with more than 4,000 kcal) that is constantly used in the field. After preparation, it was operated under normal conditions. The additive of the above example was added in a ratio of 1000:1 of the solid waste fuel input amount (usage amount). Then, the 24-hour combustion system was operated under the same load factor of 85%. After combustion was complete, a clinker sample was collected from the fuel system.

2-1. Drop crash test on clinker

A drop weight of 5 kg was dropped to the clinker produced before and after the use of the additive of the embodiment of the present invention at different heights (20 cm to 3 m), and cracks and cracks of the clinker were confirmed.

As can be seen in FIG. 2 , the required crack height was reduced by 90% (300cm -> 20cm) when using the additive of the example of the present invention, and the required impact energy was reduced by 75% (380N hammer -> 98N hammer).

These results mean that the strength of the clinker is weakened according to the use of the additive in the embodiment of the present invention, thereby making it easier to remove and remove the clinker.

2-2. Analysis of clinker propensity and composition

Immediately after the combustion of the combustion system was completed, the appearance characteristics of the clinker produced before (a total of 2 samplings)/after (a total of 4 samplings) were observed using the additive of the embodiment of the present invention, and the results are shown in FIG. indicated.

In addition, through XRF (x-ray fluorescence analyzer) analysis (analysis institution: KOLAS accredited certification institution, Korea Polymer Research Institute), the components of the clinker collected before and after the use of the additive in Examples of the present invention were compared to Table 5 and Table 6, respectively. _{After showing in Equation 2, the K 2} O index (K ₂ O INDEX), which is an index indicating the influence of clinker, was calculated based on Equation 2 below.

after use ingredient #One #2 #3 #4 average K ₂ O Index Ca 40.3 44.7 30.7 48.3 41.0 3.99% Si 26.9 25.3 29.7 21.3 25.8 Fe 4.0 3.6 3.4 3.8 3.7 Al 9.2 9.2 19.8 9.9 12.0 Mg 6.6 10.3 5.3 11.3 8.4 k 1.8 1.7 1.6 1.5 1.7 Ti 6.1 6.5 6.7 5.9 6.3 S - - - - - Mn - - - - - Cu - - - - - Cl 3 3 3 2 - V - - - - - Cr - - - - - Zn - - - - -

before use ingredient #One #2 average K ₂ O Index Ca 23.4 24.8 24.1 4.48% Si 35.4 36.6 36.0 Fe 3.1 5.9 4.5 Al 25.3 15.9 20.6 Mg 4.9 10.0 7.45 K 2.2 1.5 1.85 Ti 3.1 2.9 3.0 S 1.5 - 1.5 Mn - 1.0 1.0 Cu 1.5 - 1.5 Cl - - - V - - - Cr - - - Zn - 1.0 -

As can be seen in FIG. 3 , it was found that the strength of the clinker was low and easily removed when the additive of the example of the present invention was used.

In addition, as can be seen in Tables 2 and 3, it was found that the K ₂ O index was improved from 4.48 to 3.99 when using the additives of the examples of the present invention.

2-3. Visual comparison of clinker

The photos of the inside of the boiler before and after the use of the additives of the examples of the present invention were compared.

As can be seen in Figure 4, there was a high risk of worker injury due to the high-temperature clinker before using the additive of the example, but after the use of the additive of the example, the clinker is mass reduced (about 80% or more), preventing the risk of workers and improving safety it can be seen that

These results mean that by preventing large-sized and high-strength deformation of the clinker according to the use of the additive in the embodiment of the present invention, the removal and removal of the clinker is facilitated, so that the work safety can be improved and the cleaning time can be shortened. In addition, it is expected that the risk of burns occurring during the operation of heated clinker can be prevented, and the risk of severe crushing due to the fall of a hard large clinker can be prevented.

sintering

The additive composition for improving solid waste fuel pollutants according to the present invention inhibits the reaction of clinker-generating substances, thereby preventing clinker formation, and improving the combustion power of fuel to improve the clinker-generating environment through local flame-concentration prevention. It is characterized by improvement.

In addition, the additive composition for improving solid waste fuel pollutants according to the present invention can prevent clinker from becoming larger and stronger due to frequent dropping of clinker during boiler operation, and by weakening the strength of clinker to facilitate clinker dropping and removal work It is characterized in that the work environment risk is improved.

Claims (8)

Borax (Borax); sodium hydroxide; potassium hydroxide; polyhydric alcohol; And a solvent; Solid waste fuel (Solid Refused Fuel) additive composition for improving pollutants comprising a. According to claim 1, wherein the composition is
1 to 15 parts by weight of the borax;
1 to 5 parts by weight of sodium hydroxide;
1 to 5 parts by weight of potassium hydroxide;
0.1 to 10 parts by weight of the polyhydric alcohol; and
The composition comprising; 60 to 90 parts by weight of the solvent. The composition of claim 1 , wherein the composition does not contain hydrogen peroxide. The composition of claim 1 , wherein the composition further comprises a metallic silicate compound. 5. The method of claim 4, wherein the composition is
Based on 1 to 20 parts by weight of the metal-based silicate compound,
1 to 15 parts by weight of the borax;
1 to 5 parts by weight of sodium hydroxide;
1 to 5 parts by weight of potassium hydroxide;
0.1 to 10 parts by weight of the polyhydric alcohol; and
The composition comprising; 50 to 80 parts by weight of the solvent. The composition of claim 4, wherein the metal-based silicate compound comprises at least one selected from the group consisting of sodium silicate and calcium metasilicate. The composition of claim 1, wherein the polyhydric alcohol comprises at least one selected from the group consisting of glycerin and ethylene glycol. The composition of claim 1, wherein the composition is included in an amount of 0.1 wt% to 0.5 wt% based on 100 wt% of the solid waste fuel.

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