KR20140068691A - Method for preparation of semi-carbonized biomass pulverized fuel and pulverized fuel made therefrom - Google Patents

Abstract

The present invention relates to a manufacturing method of a pulverized semi-carbonized biomass fuel which is usable as an alternative fuel of the conventional solid fuel including coal and cokes, and liquid fuel such as diesel, kerosene, bunker fuel, etc. and to a pulverized semi-carbonized biomass fuel manufactured thereby. The pulverized semi-carbonized biomass fuel has a particulate form due to convenient pulverization in contrast with a needle form when pulverizing ordinary biomass, and is useful for smooth transportation and supply of fuel. The pulverized semi-carbonized biomass fuel has a fast ignition speed and a high heating value in combustion, contains moisture of 1 weight% or less, and has an average heating value of 5200 kcal or more, so as to be used as clean energy replacing the conventional solid fuel or liquid fuel.

Description

METHOD FOR PREPARATION OF SEMI-CARBONIZED BIOMASS PULVERIZED FUEL AND PULVERIZED FUEL MADE THEREFOROM BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

The present invention relates to a method for producing semi-carbonized biomass pulverized fuel which can be used as a substitute fuel for a conventional solid fuel such as coal coke and a liquid fuel such as light oil, kerosene, bunker oil and the like, and a pulverized fuel produced therefrom.

Recently, due to the depletion of fossil fuels and the ever-increasing greenhouse effect, there is a growing interest in the development of alternative fuels that reduce carbon dioxide emissions instead of fossil fuels, as demand for alternative or non-stationary energy sources increases. In addition, international regulations are being strengthened to cope with climate change globally. Korea has established the Green Growth Basic Law, the National Greenhouse Gas Reduction Target, and has established the 'Greenhouse Gas Energy Target Management System' and 'Renewable Energy Portfolio Standard 'system.

As a result, research has been conducted to utilize biomass as an alternative energy source. At present, both domestic and foreign industries have a preference for solid biomass energy sources, which have competitive power in terms of investment cost and manufacturing cost compared to energy sources such as solar heat, There is an active movement for use as an alternative energy source.

Korean Patent Application No. 10-2009-0080920 discloses a method and apparatus for burning a biomass pulverized fuel, but it is difficult to separate the biomass pulverized fuel due to limitation of combustion conditions due to grinding (max 0.3 mm) and moisture (5% or less) The use of a combustion device of the biomass is required to reveal the limit of improvement of the biomass fuel.

As described above, the biomass can be used as a fuel. However, in order to increase the ignition speed in the combustion process of the fuel, the biomass may be used in the form of fine particles (particle diameter of about 0.075 mm (200 mesh) or less) However, since the conventional biomass fuel has a fibrous structure in its structure, the shape of the particles at the time of pulverization has a needle-shaped structure, which limits the pulverization of the pulverized fine particles. Due to the raw material properties of the fibrous material, And it is inconvenient to supply and transport the fuel due to the content of the relatively small amount of the fine fraction and the short ignition time due to the high volatile content and the late ignition speed due to the high moisture content, There was a limit to replacing solid fuels or liquid fuels.

In addition, the conventional biomass fuel has a relatively high moisture content of 10 to 25 wt% and thus has a relatively low calorific value, thus limiting performance as a fuel.

Therefore, compared with conventional biomass fuels, fine pulverization is advantageous and sufficient degree of differentiation can be ensured, a fast ignition speed can be achieved, inconvenience of fuel transfer can be improved, high heat quantity and high efficiency can be realized, There is a great need for biomass pulverized fuels that can replace fuels or liquid fuels.

An object of the present invention is to provide a semi-carbonized biomass pulverized fuel obtained from a method for producing semi-carbonized biomass pulverized fuel and a method for producing the pulverized fuel.

In order to accomplish the above object, the present invention provides a method for producing biomass, comprising: introducing biomass raw material containing cellulose, hemicellulose, lignin and the like as a main component into a closed or lean oxygen- A semi-carbonization step of producing the semi-carbonized biomass fuel by drying the biomass raw material charged in the semi-carbonization chamber at a semi-carbonization temperature for 20 to 40 minutes; And a crushing step of crushing the semi-carbonized biomass fuel. The present invention also provides a method for producing semi-carbonized biomass pulverized fuel.

The semi-carbonization temperature may be 150 to 350 캜.

The semi-carbonization temperature may be 240 to 260 캜.

The biomass feedstock may be a woody biomass feedstock comprising 30-45 wt% cellulose, 20-30 wt% hemicellulose, 25-35 wt% lignin, 2-10 wt% water, and other residues .

The wood-based biomass feedstock may be any one selected from the group consisting of sawdust, wood chips, pulp chips, waste wood, and forest by-products.

The biomass feedstock may be an herbal based biomass feedstock comprising 20-40 wt% cellulose, 25-35 wt% hemicellulose, 10-35 wt% lignin, 5-25 wt% water, and other residues .

The herbaceous biomass feedstock may be any one selected from the group consisting of corn bran, palm kernel, coconut shell, nutshell, rice hull, cobbler, mulberry, reed, straw, E.F.B (Empty fruit bunch) and fallen leaves.

The particle size of the biomass feedstock may be between 0.075 and 250 mm.

The semi-carbonated biomass fuel may be discharged under a temperature atmosphere of 200 to 240 캜.

The semi-carbonized biomass fuel may be comprised of 40 to 52 wt.% Of cellulose, 3 to 19 wt.% Of hemicellulose, 33 to 43 wt.% Of lignin, 1 to 2 wt.% Of water and balance of other residues.

The semi-carbonization step may be performed in a state where oxygen or air is shut off.

The milling step may be performed in a tube mill.

The tube mill includes a horizontally laid rotary drum-type crusher in which the semi-carbonized biomass fuel can be crushed.

And a cooling step of cooling the semi-carbonized biomass fuel to 25 to 30 DEG C before the pulverization step.

The present invention also provides a semi-carbonized biomass pulverized fuel produced by the above-described method for producing semi-carbonized biomass pulverized fuel.

The semi-carbonated biomass pulverized fuel may have a particulate form.

The semi-carbonized biomass pulverized fuel may have a particle size distribution with a particle size of 0.15 mm or less of 70% or more.

The semicarbonated biomass pulverized fuel may have a particle size distribution in which the particle size is 2 mm or less is 100% or more.

By the method of the present invention, it is possible to produce semi-carbonized biomass pulverized fuel which can be used as a conventional solid fuel including coal coke and as an alternative fuel for liquid fuels such as light oil, kerosene, bunker oil and the like, Mass finely divided fuels are advantageous in pulverization of fine particles, and the shape of the particles is in the form of particles unlike the needle-shaped form in the case of pulverizing general biomass, which is advantageous for smooth fuel transfer and supply, has a fast ignition speed, And contains not more than 1% by weight of water and has an average calorific value of 5200 kcal or more and can be used as a clean energy replacing conventional solid fuels or liquid fuels.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a graph showing changes in constituent components of a woody raw material by temperature change according to Example 1 of the present invention. FIG.
FIGS. 2 and 3 are graphs showing energy variation widths of the semi-carbonized biomass raw material according to the temperature change according to the first embodiment of the present invention.
FIG. 4 is a graph showing the results of measurement of the thermal changes of the fuel according to Examples 10 and 11 and Comparative Examples 5 and 6 according to the temperature using differential thermal analysis (TG-DTA).

Hereinafter, preferred embodiments of the present invention will be described in detail.

In one embodiment, the present invention provides a method for producing biomass, comprising: introducing biomass raw materials containing cellulose, hemicellulose, lignin, etc. as a main component into a closed semi-carbonization chamber; Carbonizing the biomass raw material charged in the semi-carbonizing chamber at 240 to 260 캜 for 20 to 40 minutes; And a pulverizing step of pulverizing the semi-carbonized biomass feedstock.

In the method of the present invention, the biomass raw material is not particularly limited as long as its cell wall is a biomass containing cellulose, hemicellulose and / or lignin as a main component. Specifically, the biomass raw material is a biomass raw material in which the main component is composed of 30 to 45 wt% of cellulose, 20 to 30 wt% of hemicellulose, 25 to 35 wt% of lignin, 2 to 10 wt% of water, Wood-based biomass such as sawdust, wood chips, waste wood and forest by-products, or 20 to 40 wt% cellulose, 25 to 35 wt% hemicellulose, 10 to 35 wt% lignin, 5 to 25 wt% Herbaceous plants such as corn bran, palm kernel, coconut shell, nutshell, rice husk, strawberry, Miscanthus, Phragmites, Rice straw, EFB (Empty fruit bunch) Based biomass. More specifically, the biomass feedstock comprises pine wood waste or 41% by weight cellulose, 19.2% by weight cellulose, consisting of 40% by weight of cellulose, 28.5% by weight of hemicellulose, 27.7% by weight of lignin, 3.8% by weight of water and other residues, Woody biomass feedstock such as hemicellulose, 31.3% lignin, 8.5% moisture, and other residues of oak waste wood may be used, and 39.9% by weight of cellulose, 23.8% by weight of hemicellulose, 13 Consisting of lignin in weight percent, rice straw in 23.3 weight percent water and other residues, 39.8 weight percent cellulose, 31.5 weight percent hemicellulose, 20.3 weight percent lignin, 8.4 weight percent water, and other residues , 40.4% by weight of cellulose, 27.1% by weight of hemicellulose, 23.6% by weight of lignin, 8.9% by weight of water and other residues Or a herbaceous biomass feed such as EFB consisting of 20.8 weight percent cellulose, 22 weight percent hemicellulose, 34.2 weight percent lignin, 23 weight percent water, and other residues.

The hemicellulose component among the hemicellulose, lignin and cellulose components is decomposed at the semi-carbonization temperature, while the main component such as wood vinegar, tar and the like is mainly generated in an anoxic condition and CO2, H2O and the like in the case of oxygen are explained. . Therefore, oxygen and hydrogen components such as wood vinegar, tar and the like are removed through the semi-carbonization step, the carbon component is concentrated, and the lignin having the carbon-hydrogen bond, the ether bond and the carbon-carbon bond structure is left The energy density can be increased. As a result, the semi-carbonated biomass fuel has a faster ignition rate and higher thermal efficiency than the conventional biomass fuel.

The particle size of the biomass raw material is about 0.075 to 250 mm, and may be about 2 to 10 mm. If the particle size is less than 0.075 mm or more than 250 mm, a uniform semi-carbonization may not be obtained and a suitable semi-carbonized raw material composition may not be obtained. If the particle size is more than or less than the moisture content in the semi-carbonized biomass It is difficult to maintain proper moisture content necessary for the molding process.

Preferably, the semi-carbonization step is carried out at a semi-carbonization temperature for 20 to 40 minutes and is performed in a state where oxygen or air is shut off. The semi-carbonization temperature is preferably 150 to 350 ° C, more preferably 240 to 260 ° C. Since the temperature of the inside of the semi-carbonizing chamber rises due to the radiant heat generated in the semi-carbonization step, the components of the biomass raw material, particularly the hemicellulose component, are decomposed and water and volatile substances such as wood vinegar, tar, The semi-carbonization process for the biomass raw material can be carried out without going through the carbonization process. At this time, among the constituents of the biomass raw material, hemicellulose is first decomposed at a low temperature, and then cellulose and lignin are sequentially decomposed. Lignin, which is a carbon-hydrogen bond, cellulose, ether bond and carbon- Because of the high density, the semi-carbonization step of the present invention is preferably carried out under optimal pyrolysis (semi-carbonization) conditions in which the lignin content in the biomass feedstock is maximized and energy loss is minimized.

After the semi-carbonization step is completed, the obtained semi-carbonated biomass fuel is discharged under a temperature atmosphere of 200 to 240 캜.

At this time, the semi-carbonized biomass fuel changes in characteristics from existing biomass raw materials, and is composed of 40 to 52 wt% of cellulose, 3 to 19 wt% of hemicellulose, 33 to 43 wt% of lignin, 1 to 2 wt% Moisture, and other residues of the balance.

The milling step may be performed in a tube mill, although not limited thereto. The tube mill includes a horizontally laid rotary drum-type crusher in which the semi-carbonized biomass fuel can be crushed.

Meanwhile, before the biomass raw material is introduced into the semi-carbonization chamber, a separate drying treatment may be further performed to lower the moisture content of the biomass raw material. The moisture content of the ingredients is an important condition for entering the semi-carbonization stage, which generally has a moisture content of about 25 to 35% by weight for woody raw materials and about 30 to 70% by weight for herbal raw materials. The moisture content of suitable raw materials to enter the semi-carbonization stage is about 25-30 wt%. Therefore, if the moisture content of the raw material exceeds the above preferable moisture content range, another drying treatment can be further performed.

Before the semi-carbonized biomass fuel is pulverized, the semi-carbonated biomass fuel may further be cooled to 25 to 30 ° C.

The semi-carbonized biomass pulverized fuel produced through the above steps may have a particulate form, and the semi-carbonized biomass pulverized fuel may have a particle size of 0.15 mm or less and a particle size distribution of 70% or more and / or 2 mm or less of 100% Or more. Therefore, it is advantageous for smooth fuel transfer and supply, has a high ignition rate, has a high calorific value during combustion, contains less than 1% by weight of water and has an average calorific value of 5200 kcal or more, .

Specifically, the method for producing the pulverized fuel of the present invention can be carried out by the following procedure.

Injection step

At least one biomass feedstock selected from woody biomass and herbaceous biomass is stored in the feed storage hopper. The stored feedstock is then conveyed via a conveyor belt to a feedstock hopper in the semi-carbonization facility dosing device. The feedstock from the feed hopper is introduced into the semi-carbonization chamber of the semi-carbonization plant quantitatively by means of a hydraulic cylinder by means of a hydraulic cylinder type feedstock feeder. At this time, the speed is 1.3 ton / hr, the advance speed of the hydraulic cylinder is 160 mm / sec, and the capacity of the hydraulic pump installed at the lower portion can be processed at a rate of 48 L / min. The semi-carbonizing chamber may be a horizontal cylindrical semi-carbonizing chamber, and may be used in a conveyor-type kiln, a shaft kiln, a rotary kiln, a railway tunnel kiln, and the like.

On the other hand, when the moisture content of the biomass raw material is higher than about 25 to 30% by weight, an additional drying treatment step may be performed before the biomass raw material is put into the semi-carbonization chamber.

Semi-carbonization  step

The raw material to be fed into the semi-carbonization chamber set at a temperature of about 250 ° C is semi-carbonized by removing moisture, removing volatile matter and trace amounts of wood tar from hemicellulose decomposition. At this time, the calorific value of the input raw material is about 3800 kcal including the moisture (4,360 kcal dry basis). The semi-carbonized chamber is rotated for uniform semi-carbonization of the raw material and for product transfer in the semi-carbonized chamber. The components generated and removed by the semi-carbonization of the raw material in the semi-carbonization chamber are discharged through the exhaust pipe connected to the closed semi-carbonization chamber and passed to the refining facility. Flammable volatilization gas remaining after the purification of the liquid and the tar is reused as a secondary energy source by recycling the semi-carbonization equipment to the heating combustion unit. The semi-carbonization step is carried out for about 30 minutes under an atmosphere of about 250 ° C. At this time, the time during which the biomass material remains in the semi-carbonization chamber and the rotation speed of the semi-carbonization chamber may be different depending on the end of the raw material, the property, and the moisture content, and can be appropriately adjusted according to the optimum degree of semi-carbonization .

Evacuation and cooling steps

According to the controlled temperature, the feedstock is fed to the discharge port by rotation of the semi-carbonization chamber. The semi-carbonated biomass fuel discharged from the semi-carbonization chamber exhibits a brown color with a high calorific value of about 5,500 kcal. At this time, the temperature change to the inlet and outlet of the raw material occurs about ± 10 ° C according to the temperature gradient of the heated semi-carbonized chamber. For example, the discharge temperature of the semi-carbonized biomass fuel is about 200 to 240 캜. At this time, the raw material is cooled to room temperature (about 25 to 30 ° C) by a cooling device (refrigerant) installed in the mixing and transferring device. Because of the high likelihood of ignition of fuel released to the atmosphere when not cooled, the semi-carbonized biomass fuel must be cooled or otherwise removed through ignition.

During the semi-carbonization process, water and volatile gases generated in the semi-carbonization facility are separated into water and other byproducts through the purification process and can be reused as the energy required to heat the combustible volatile gas semi-carbonization chamber.

Crushing step

The semi-carbonated biomass fuel is cooled to room temperature and then transported to the crushing line. The equipment used for crushing can be used without particular limitation as long as it can crush the semi-carbonized biomass fuel, preferably a tube mill is used. The tube mill includes a horizontally laid rotary drum type crusher, the fuel is continuously charged into the crusher, and the charged fuel is charged into the drum by large and small steel balls of about 10% volume by volume It is crushed by mutual impact. The fuel pulverized to a certain size (less than about 0.3 mm) is sucked and discharged from a cyclone-type dust collector installed outside the mill. The particle size of the pulverized fuel through the tube mill is close to 100% with a particle size of 2 mm or less, and more than 70% with a particle size of 0.15 mm or less.

Hereinafter, examples and comparative examples of the present invention will be exemplified. The following embodiments are illustrative and are provided to aid understanding of the present invention, and thus the technical scope of the present invention is not limited thereto.

I. Semi-carbonated Biomass  Raw material manufacturing method

Example  One.

In order to investigate the change characteristics of the constituents according to the half-carbonization degree of the biomass, about 28% by weight of cellulose, about 26% by weight of hemicellulose, about 23% by weight of lignin, about 3% by weight of other residues, % Of moisture was dried for 30 minutes at 230 ° C, 240 ° C, 250 ° C, 260 ° C and 270 ° C, respectively, to carry out semi-carbonization. The contents of the components constituting the raw materials and the contents of the components constituting the semi-carbonized biomass fuel under the respective temperature conditions are shown in Table 1 below.

Semi-carbonization temperature cellulose Hemicellulose Lignin ash Etc moisture 0 ℃
(Raw material) 27.63% 25.87% 23.35% 0.36% 2.80% 19.99% 230 ℃ 37.60% 24.87% 31.36% 0.73% 3.71% 1.73% 240 ℃ 40.61% 18.14% 33.93% 0.60% 5.06% 1.66% 250 ℃ 47.07% 9.86% 39.50% 0.91% 1.52% 1.14% 260 ℃ 51.57% 3.14% 42.00% 0.90% 1.22% 1.17% 270 ℃ 49.61% 3.34% 42.95% 1.79% 1.28% 1.04%

As shown in Table 1, it can be seen that most of the hemicellulose constituting the woody biomass is decomposed at a temperature of around 230 ° C, while the cellulose and lignin remain almost undecomposed (see FIG. 1). That is, since the lignin component starts to decompose at a higher temperature than hemicellulose, it is confirmed that the semi-carbonization temperature condition in which the lignin component capable of increasing the energy density per unit weight is maximum is 240 to 260 ° C.

Experimental Example  One.

The calorific value, recovery rate, energy loss and energy density of the semi-carbonized woody biomass fuel obtained under the respective temperature conditions of Example 1 are shown in Table 2 below.

Half carbonization degree
(Temperature) Product recovery rate (%) Calorific value
(DB) Energy loss
(? H ₁ ) Residual energy
(? H ₂ ) Energy density
(ΔH ₂ / H · kg) 0 ℃ (raw material) 100.00 4,360 kcal 0 kcal 4,360 kcal One 230 ℃ 91.70 4,420 kcal 307 kcal 4,053 kcal 1.01 240 ℃ 83.67 4,750 kcal 386 kcal 3,974 kcal 1.09 250 ℃ 71.36 5,500 kcal 435 kcal 3,925 kcal 1.26 260 ℃ 62.51 5,625 kcal 844 kcal 3,516 kcal 1.29 270 ℃ 50.35 5,740 kcal 1,470kcal 2,890 kcal 1.32

According to the results of Table 2, the recovery ratio of the product tends to decrease as the internal temperature of the semi-carbonized chamber increases. In particular, it can be seen that the rate of change of the recovery rate decreases by 8 to 12% (Δw / Δt) as the temperature increases. This can be attributed to the difference in speed at which the components of the raw material are decomposed according to the semi-carbonization condition. It can be confirmed that the decrease in half-carbonization is increased at a temperature of 250 ° C or more. The calorific value of the semi-carbonized product also tends to increase as the degree of semi-carbonization increases. Especially, in the semi-carbonization condition after 250 ℃, the heating value of the product increased by about 750 kcal compared to the raw material. This is also attributed to the concentration of the remaining carbon components and the concentration of the lignin component which can generate a high calorific value in the semi-carbonization process.

Then, the residual energy and the energy loss according to the temperature change and the calorific value of each of the semi-carbonized biomass fuels obtained in Example 1 were measured (see FIG. 2). At this time, the residual energy showed a gradual decrease in the initial temperature, but the decreasing tendency (slope) tended to increase after 250 ° C. Also, energy losses tend to increase while keeping constant. From these results, it was confirmed that the conditions for producing the optimal semi-carbide fine fuels were in the temperature range of 240 to 260 캜, in which the recovery rate was high and the energy loss was kept to a minimum while maintaining the components of lignin as much as possible. It was confirmed that the optimum semi-carbonization was carried out at a temperature of 250 ° C.

Further, the energy density tends to increase as the semi-carbonization proceeds from the energy density change due to the change in the weight of the fuel due to the half-carbonization (see FIG. 3). Especially, the increase of the energy density at the temperature of 240 ℃ or higher was increased, and the trend of increasing again after 250 ℃ was observed. This is considered to be due to the fact that the change in weight is relatively larger than the enrichment ratio of the semi-carbonized fuel. From these results, it was confirmed that the semi - carbonization condition of 250 ℃, which is the interval in which the variation width of energy reduction is the lowest, and the recovery rate of the semi - carbonized product is the highest, that is, the range of variation of the energy density is the optimum condition.

Example  2 to 4 and Comparative Example  1-3

Sawdust consisting of 23% by weight of cellulose, 20% by weight of hemicellulose, 29% by weight of lignin, 25% by weight of water and the balance of other residues was dried at a temperature of about 230 to 270 캜 for 30 minutes Carbonization) to produce semi-carbonized biomass fuel. The physical properties of each obtained semi-carbonized biomass fuel are shown in Table 3 below.

Raw material Comparative Example 1 Example 2 Example 3 Example 4 Comparative Example 2 Comparative Example 3 Drying temperature 230 ℃ 240 ℃ 250 ℃ 260 ℃ 270 ℃ 300 ° C> Lignin content
(g) 29.2 28.81 28.87 28.51 26.57 21.85 <5 Semi-carbonization
Raw material yield
(%) 100 91.70 83.67 71.36 62.51 50.35 <35 Calorific value 4,360 4,420 4,750 5,500 5,625 5,740 > 6,000 energy
Density (ΔH ₂ / H · kg) 1.00 1.01 1.09 1.26 1.29 1.32 <1.30

As shown in Table 3, it can be seen that the calorific value varies depending on the drying (semi-carbonization) temperature. That is, it can be seen that the semi-carbonized biomass raw material of the present invention has the lowest heating value and a small decrease in lignin content at a temperature of 240 to 260 ° C.

II . Semi-carbonated Biomass  Particle size and particle size of pulverized fuel Semi-carbonization  Combustion Efficiency by Temperature

Example  5 to 9 and Comparative Example  4

To investigate the combustion efficiency according to the particle size of semi-carbonized biomass pulverized fuel, it was found that about 28 wt% cellulose, about 26 wt% hemicellulose, about 23 wt% lignin, about 3 wt% The sawdust containing 20% by weight of water was dried (semi-carbonized) for 30 minutes at 150 ° C, 200 ° C, 250 ° C, 300 ° C and 350 ° C, respectively, to produce semi-carbonized biomass fuel. Each of the obtained semi-carbonized biomass fuels is classified into a condition in which the particles having a particle size of 3.0 mm or less occupies 70% or more, a condition in which particles having a particle size of 1.0 mm or less occupies 70% or more, Crushed under the condition that the particles occupying not more than 0.18 mm account for not less than 70% and the particles not larger than 0.15 mm account for not less than 70%, to produce semi-carbonized biomass pulverized fuels of various grain sizes, And the results are shown in Table 3 below. Combustion efficiency is achieved by analyzing the residual carbon content in the recovered softwood. The unburned carbon content is made by the LOI (Loss On Ignition) method, and the combustion efficiency is calculated by the ash content in the semi-carbonized biomass pulverized fuel and the unburned carbon in the pulverized fuel as described below. Here, Ash _fuel and LOI mean the content of ash in the semi-carbonized biomass pulverized fuel and the unburned carbon content in the coal ash after combustion, respectively.

Combustion efficiency (%) = {1 - (Ash _fuel * LOI) / (100-Ash _fuel * (100-LOI)

Raw material processing temperature

Grain size (70%) Comparative Example 4
(Not semi-carbonized) Example 5
(150 DEG C) Example 6
(200 DEG C) Example 7
(250 DEG C) Example 8
(300 DEG C) Example 9
(350 DEG C) 3.0 mm 78.89 89.26 92.31 93.03 93.77 94.76 1.0 mm 85.71 93.65 94.78 95.06 95.41 96.09 0.3mm 88.95 97.64 97.81 98.34 98.66 98.88 0.18mm 90.60 98.59 98.88 99.36 99.44 99.47 0.15mm 91.58 99.34 99.54 99.87 99.90 99.90

According to the results shown in Table 4, in the case of the general biomass fuel without the semi-carbonization (Comparative Example 4), the combustion efficiency according to the particle size of the fuel was 79% to 91% %. &Lt; / RTI &gt; The higher the half-carbonization temperature, the higher the combustion efficiency. When the particle size of the fuel is 0.3 mm or less and the half-carbonization is carried out at a temperature of 150 ° C., the combustion efficiency increases from 89% to 97%, which is more than 95%. However, even under the condition that the particle size of the fuel is relatively large, 3.0 mm or more, the combustion efficiency does not exceed 95% even considering the combustion efficiency increase effect due to the half-carbonization. When the particle size is 3.0 mm or less, The combustion efficiency increases to 99.9% as the semi-carbonization temperature increases. From these results, in order to improve the combustion efficiency of the semi-carbonized biomass pulverized fuel, it is preferable that the particle size of the fuel is not more than 1.0 mm but not more than 70%, and the semi-carbonization temperature is in the range of 150 to 350 ° C , And it is more preferable to set the semi-carbonization temperature to 240 to 260 ° C.

III . Semi-carbonated Biomass  Differential fuel Semi-carbonization  Ignition temperature and ignition duration according to temperature

Example  10-11 and Comparative Example  5 to 6

The semi-carbonized biomass pulverized fuel was prepared by drying (wood-carbonizing) ordinarywood wood powder at a temperature of 150 ° C to 200 ° C for 30 minutes and pulverizing the pulverized wood so that particles having a diameter of 0.3 mm or less accounted for 70% (Example 11) was prepared by varying the temperature condition only at 200 ° C to 250 ° C, and the fully carbonized biomass pulverized fuel (Comparative Example 5) was heated to 350 ° C or higher only in the temperature condition. And wood pulp (Comparative Example 6) was prepared by pulverizing commonwood wood powder such that particles having a diameter of 0.3 mm or less accounted for 70% or more. The results are shown in the graph of FIG. 4 by measuring the thermal change of each fuel by using differential thermal analysis (TG-DTA) while burning the obtained biomass fuels.

Referring to FIG. 4, in the case of Examples 10 and 11 and Comparative Example 6, the initial peak shows a rising shape at a temperature interval of about 320 ° C. This is an interval in which the exothermic reaction of fuel starts, And the ignition is an exothermic reaction. In this case, the volatile matter is a combustible gas generated by decomposing components such as cellulose, hemicellulose, and lignin constituting the fuel. The initial peak temperatures of the three types of fuels show a slight difference of about 2 ° C or less, and Comparative Example 6 is 328.32 ° C, which is the highest peak value of the peak heat amount in Example 10 (325.29 ° C) and Example 11 (322.54 ° C) And the area of the graph is also shown to be the widest. Thereafter, the three kinds of fuels exhibit a second peak in the temperature range of about 454 ° C to 468 ° C. Specifically, in Comparative Example 6, 468.31 ° C, Example 10 (454.37 ° C) and Example 11 (457.99 ° C ), And thus the content of char component and carbon component causing the second exothermic reaction as compared with the fuel of Examples 10 and 11 in which the fuel of Comparative Example 6 which had not undergone the semi-carbonization process underwent the half-carbonization process Is relatively low. In this case, the time required from the initial ignition of each fuel to the completion of the combustion reaction was shorter in the order of 21 minutes for Comparative Example 6, 19 minutes for Example 10, and 14 minutes for Example 11.

This means that the fuel of Comparative Example 6, which has not undergone the semi-carbonization process, uses a relatively large amount of combustible components in the initial combustion reaction as compared with the fuel of Examples 10 and 11 which undergo the half-carbonization process, The combustion rate by the combustible gas component is higher than the combustion rate of the solid carbon components. In addition to carbon dioxide (CO2), water (H2O) is also generated in the combustion products of combustible gas components of biomass fuels. This moisture is a factor that can lower the carbon burning reaction rate of the secondary peak, There is a high possibility of causing incomplete combustion. Considering that the combustion efficiency of the fuel is increased in the combustion reaction by the combustion apparatus, when the combustion reaction by the combustible gas is dominant as in Comparative Example 6, the combustion reaction of the fixed carbon component remaining in the fuel proceeds And the incompletely combusted fuel tends to be discharged together with Ash. In addition, when the fuel curves are compared based on the height and area of the first peak, the start time of ignition is similar, but the combustion time required for completing the combustion reaction after the initial ignition is as follows: Example 11> Example 10> 6> Comparative Example 5 in that order. These experimental examples show that the semi-carbonized or dried fuel maintains the advantage of the rapid ignition speed of the untreated general biomass fuel and shortens the slow combustion time to increase the combustion efficiency of the fuel, Which is the fuel supplemented with the fuel.

On the other hand, in the case of Comparative Example 5, unlike the cases of Examples 10 and 11 and Comparative Example 6, peaks rising in the temperature range of about 320 ° C to 570 ° C were not observed because volatile components were removed by complete carbonization, An exothermic reaction by the carbon component occurs at 644 ° C. Compared with the second exothermic reaction of Comparative Example 6, this is a relatively higher temperature because the surface combustion of char or carbon components is performed primarily without the catalytic effect associated with the exothermic reaction by the combustion of the initial volatile components Because.

The results are shown in Table 5 below.

Example 10 Example 11 Comparative Example 5 Comparative Example 6 Ignition temperature
(The temperature at which the initial peak appears) 325.29 DEG C 322.54 DEG C X 328.32 DEG C temperature at which an exothermic reaction occurs due to char, carbon components, etc. 454.37 DEG C 457.99 DEG C 649.53 DEG C 468.31 DEG C Burning time 19 minutes 14 minutes 21 minutes More than 30 minutes

Claims (18)

Introducing a biomass raw material containing cellulose, hemicellulose, lignin and the like as a main component into a closed semi-carbonization chamber;
A semi-carbonization step of producing the semi-carbonized biomass fuel by drying the biomass raw material charged in the semi-carbonization chamber at a semi-carbonization temperature for 20 to 40 minutes; And
And a crushing step of crushing the semi-carbonized biomass fuel. The method according to claim 1,
Wherein the semi-carbonization temperature is 150 to 350 占 폚. The method according to claim 1,
Wherein the semi-carbonization temperature is 240 to 260 ° C. 4. The method according to any one of claims 1 to 3,
The biomass feedstock is a ligneous biomass feedstock comprising 30-45 wt.% Cellulose, 20-30 wt.% Hemicellulose, 25-35 wt.% Lignin, 2-10 wt.% Water and other residues Wherein the biomass fuel is a biomass fuel. The method of claim 4,
Wherein the woody biomass feedstock is any one selected from the group consisting of sawdust, wood chips, pulp chips, waste wood, and forest by-products. 4. The method according to any one of claims 1 to 3,
The biomass feedstock is an herbal biomass feedstock comprising 20-40 wt% cellulose, 25-35 wt% hemicellulose, 10-35 wt% lignin, 5-25 wt% water, and other residues Wherein the biomass fuel is a biomass fuel. 4. The method according to any one of claims 1 to 3,
The biomass feedstock is an herbal biomass feedstock comprising 20-40 wt% cellulose, 25-35 wt% hemicellulose, 10-35 wt% lignin, 5-25 wt% water, and other residues Wherein the biomass fuel is a biomass fuel. 4. The method according to any one of claims 1 to 3,
Wherein the particle size of the biomass feedstock is 0.075 to 250 mm. 4. The method according to any one of claims 1 to 3,
Wherein the semi-carbonized biomass fuel is discharged under a temperature atmosphere of 200 to 240 캜. 4. The method according to any one of claims 1 to 3,
The semi-carbonized biomass fuel is composed of 40 to 52% by weight of cellulose, 3 to 19% by weight of hemicellulose, 33 to 43% by weight of lignin, 1 to 2% by weight of water, Wherein the biodegradable fuel is biodegradable. 4. The method according to any one of claims 1 to 3,
Wherein the semi-carbonization step is performed in a state where oxygen or air is blocked. 4. The method according to any one of claims 1 to 3,
Wherein the milling step is performed in a tube mill. &Lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt; The method of claim 12,
Wherein the tube mill comprises a horizontally laid rotary drum type mill, wherein the semi-carbonized biomass fuel is pulverized within the mill. 4. The method according to any one of claims 1 to 3,
Further comprising a cooling step of cooling the semi-carbonized biomass fuel to 25-30 占 폚 prior to the pulverizing step. A semi-carbonated biomass pulverized fuel produced by the process according to any one of claims 1 to 3. 16. The method of claim 15,
Wherein the semi-carbonated biomass pulverized fuel has a particulate form. 18. The method of claim 16,
Characterized in that the semicarbonated biomass pulverized fuel has a particle size distribution in which the particle size is 0.15 mm or less is 70% or more. 18. The method of claim 16,
Wherein the semi-carbonized biomass pulverized fuel has a particle size distribution in which the particle size is 2 mm or less is 100% or more.

Images