KR101427724B1 - manufacturing method of solid fuel from sludge - Google Patents

Abstract

The present invention is a method for preparing a solid fuel from a waste sludge, which can make a pellet-shaped solid fuel at a low cost and a high efficiency. More specifically, the method for preparing a solid fuel from a waste sludge comprises the processes of: treating the waste sludge; treating a municipal waste; mixing a lysate; and molding. In the mixing a lysate, a sludge lysate and a flammable lysate are mixed at a ratio of 4:6 to 2:8. In the molding, a compressed and molded pellet has a calorific value of 4,700 to 4,924 kcal/kg, and a content of 0.94 to 1.1 wt% of chlorine, 5.2 to 6.0 wt% of moisture, 20.1 to 16.1 wt% of ash, and 0.1 to 0.02 wt% of sulfur.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for manufacturing a sludge sludge,

More particularly, the present invention relates to a method for producing a sewage sludge by forming municipal solid waste by mixing sewage sludge with municipal solid waste, The present invention relates to a method for manufacturing a sintered fuel of a sewage sludge capable of producing a pellet type solid fuel at a low cost and a high efficiency by reducing the amount of the sludge to less than a reference value while satisfying the solid fuel quality standard according to the content of ash and ash.

Generally, the sewage sludge generated in the sewage treatment process contains 97 ~ 99% of water, and most of the sewage sludge is finally disposed of through a dehydration process. More than 50% of domestic sewage sludge has been dumped by 2011, but since 2012, marine dumping has been banned entirely under the London Convention, and it has been treated with various reduction technologies such as incineration, carbonization, solidification and dry fuel conversion.

Since most of the solid matter, which accounts for 1 ~ 3% of sewage sludge, is composed of organic matter, it is recommended to utilize it as auxiliary fuel of the power plant and cement production facility by dehydration and drying according to the national resource policy. And the use of excess fuel such as LNG due to desiccation has raised the problems of resource conversion and fuel conversion, and appropriate technological development measures are required.

More specifically, the sewage sludge having a water content of 97 to 99% is dehydrated to a moisture content of about 85% at the sewage treatment plant and directly dried and solidified, so that the capacity of the sewage sludge is inevitably uneven, LNG and so on, it is necessary to consume excessive amount of fuel such as LNG in order to dry dehydrated sludge with moisture content of about 85% and sludge having moisture content of less than 10% The cost of produced fuel is remarkably low, which is pointed out as a drawback in terms of efficiency. In addition, the calorific value of the fuel thus produced is 3,000 ~ 3,500 kcal / kg, which is lower than the calorific value of the national standard fuel, resulting in a deterioration in quality as an auxiliary fuel.

Accordingly, in recent years, in order to overcome the above-mentioned problems, it has been proposed to mix industrial wastes with sewage sludge to produce solid fuel, and Korean Unexamined Patent Publication No. 2002-0015759 (2002.03.02) A method for producing solid fuel using waste water sludge and combustible waste and dried food waste "has been proposed.

The method for producing a solid fuel using the sewage / wastewater sludge and combustible waste and the food waste dried product is characterized in that a sludge cake, a food waste, and a combustible waste powder of a high calorific value (waste tire, waste vinyl, Polysilane, waste PET, waste HDPE, etc.) at a predetermined ratio to crush and mix as a mixed feeder; A second step of putting the mixed sludge cake, the dried food waste, and the combustible waste powder into a molding machine to solidify the mixed sludge cake to a predetermined size; A third step of drying the molded article in a dryer in which hot air generated from the combustion means is supplied; A fourth step of injecting the dried solid fuel into the combustion means in a predetermined amount; In the first step, the sludge cake, the food waste, and the combustible waste powder are mixed at a ratio of 50%: 30%: 20%.

In addition, Korean Patent Publication No. 2002-0080541 (Oct. 26, 2002), entitled " Method for producing waste solid fuel ", has been proposed, which is a method for producing industrial solid waste as solid fuel, , Waste paper and sludge into a raw material processing facility at a predetermined ratio, sorting and removing the ferrous metal by magnetic force sorting, and crushing the ferrous metal-removed raw material; The raw material crushed in the raw material processing step is put into a drier and dried with hot air to select a lightweight material (paper, vinyl, etc.) and a heavy material (sludge, superfine magnet, nonferrous metal, plastic, etc.) To the mixer, and transferring the weight to the next forming process; The heavy material to be dried and selected and conveyed to the next molding process is pulverized by a pulverizer, and the pulverized pulverized material is pulverized through two vibrating bodies, a wind separator, a cyclone and a bag filter using a specific gravity difference of the heavy material, Wherein the superfluid, the non-ferrous metals and the plastics are sorted and stored, a part of the sludge is transferred to a mixer, and another part of the sludge is recirculated to the dryer Sorting process; A mixing step of mixing the light weight water (paper, vinyl, etc.), which is dried and selected in the drying step, and the sludge discharged and pulverized in the sorting step, in the mixer; A step of molding the mixed lightweight material and the sludge in the mixer into a waste solid fuel in the form of a pallet by a molding machine; Storing the waste solid fuel formed by the molding machine in a storage tank; And a step of collecting the odor air generated in the raw material processing step and the hot air generated in the drying step through a collecting device and transferring the air to the hot air generating device as combustion air and exhausting the filtered air through the air pollution control device will be.

In addition, Korean Patent Laid-Open Publication No. 2013-0040450 (Apr. 24, 2013) "Method for producing solid fuel using sludge and combustible waste" has been proposed, which comprises 45% by weight of sludge and 25% by weight of pulverized MDF powder 15 5 wt% of waste tire powder, 5 wt% of waste oil sludge, 2.5 wt% of liquid strengthening agent and 2.5 wt% of magnesium hydroxide are stirred at a time to produce a mixture, and the water content of the mixture is adjusted to 15 to 25% Mixing process; A production step of pressing the mixture to form a predetermined shape; And a drying step of drying the molded product so that the moisture content is within 10%. However, since the production method of the solidified fuel of the sewage sludge does not meet the calorific value of the main raw material, it can not only be used as an auxiliary fuel, but also requires a large cost due to energy consumption, resulting in a low cost.

1. Korean Patent Publication No. 2002-0015759 (Mar. 02, 2002) "Method of producing solid fuel using sewage / wastewater sludge, flammable waste and food wastes dried product" 2. Korean Patent Publication No. 2002-0080541 (Oct. 26, 2002) "Method of producing waste solid fuel" 3. Korean Patent Laid-Open Publication No. 2013-0040450 (Apr. 24, 2013) "Method for producing solid fuel using sludge and combustible waste"

SUMMARY OF THE INVENTION Accordingly, the present invention has been made keeping in mind the above problems occurring in the prior art, and it is an object of the present invention to provide a method of producing municipal solid waste by mixing municipal waste with sewage sludge, Which can produce pellet type solid fuel with low efficiency and high efficiency by reducing the amount of the fly ash to meet the standard of solid fuel quality according to the content of chlorine, moisture, ash and sulfur, Method.

To achieve these and other advantages and in accordance with the purpose of the present invention, as embodied and broadly described herein, there is provided a method for manufacturing a sewage sludge, comprising: subjecting a sludge having a water content of 97 to 99% or more to a water content of 60 to 70% A sewage sludge treatment step of treating the sludge with a water content of less than 10 to 15% by using a rotary impact type drier; A municipal waste treatment process in which flammable waste is selected from municipal wastes, crushed by a crusher, and processed into a flammable waste having a calorific value of 5,500 kcal / kg or more with a moisture content of less than 10 to 15% by using a rotary impact type drier; A sludge disintegration step of mixing a sludge crush having a water content of less than 10 to 15% and a combustible crush having a calorific value of less than 10 to 15% and having a calorific value of 5,500 kcal / kg or more prepared through the sewage sludge treatment process and the municipal waste treatment process; Wherein the mixture of sludge and flammable material is mixed with the sludge material and the combustible material by compression molding in the form of pellets by a molding machine. The pellets obtained by compression molding in the molding process have a calorific value of 4,700 to 4,924 kcal / kg and contain 0.94 to 1.1% wt of chlorine, 5.2 to 6.0% wt of moisture, 20.1 to 16.1% wt of ash, 0.1 to 0.02% wt of sulfur By weight.

As described above, the present invention has a heat generation amount exceeding a national standard for use as a main fuel at low cost when municipal sludge is mixed with municipal solid waste and is produced as solid fuel, and has a solid fuel quality according to the content of chlorine, moisture, It is possible to manufacture pellet type solid fuel at a low cost and high efficiency by reducing the amount of the fly ash while satisfying the standard, and it is possible to reduce the cost of transporting and landing the sludge to be landfilled, And sludge treatment cost by sludge disposal facility can be reduced, and economic efficiency and cost competitiveness can be secured.

FIG. 1 is a block diagram showing a process for producing a molded fuel of a sewage sludge according to the present invention.
2 is a view showing a pretreatment process of the sewage sludge dewatering process of the present invention.
FIGS. 3A to 3C are views showing a process of dry-crushing sludge crushing products and combustible crushing products according to the present invention. FIG.
4 is a photograph showing a pellet molded according to the present invention.

As shown in FIG. 1, the present invention comprises a sewage sludge treatment process, a municipal waste treatment process, a mixing process, and a molding process, which will be described in detail for each process.

(Sewage sludge treatment process)

In this process, sewage sludge having a water content of 97 to 99% or more is dehydrated by a compression dehydrator at a water content of 60 to 70%, and then processed into a sludge disintegration product having a moisture content of less than 10 to 15% by using a rotary impact type drier.

The squeezing-type dehydrator comprises a filling-compression-relaxation / filling-discharging process as shown in FIG. More specifically, the drum is filled with sewage sludge by a pump, and the sewage sludge in the drum is compressed by a piston to discharge the filtrate through the filter element. Then, the dewatered cake is separated from the filter element as the piston is loosened, the cylinder is rotated at low speed to homogenize the sludge and the cake to be filled, and the filling and pressing process is repeated to reach the required condition. The cylinder housing is opened and the dewatering cake is discharged.

≪ Example 1 >

The dewatering experiment is the result of the operation of two hydraulic dehydrators installed at the water quality restoration center in Namyangju City which is installed in the basin. The water content of sludge is 98.9 ~ 99.1% and the water content after dehydration is 60.3 ~ 69.3% (average 65.9%) have.

 Dehydration experiment result division Input (ton) Influent Water Rate (%) Time required (min) Final water content (%) One 26.2 99.0 118.7 57.7 2 26.4 99.1 126.6 61.6 3 26.6 99.1 112.3 61.3 4 26.4 99.1 125.9 61.5 5 25.7 99.0 131.9 60.7 6 25.5 99.0 151.9 58.8 7 25.4 99.0 129.7 59.0 8 25.8 99.0 106.0 58.3 9 24.4 99.0 92.1 60.6 10 26.8 99.2 89.9 65.4 11 26.6 98.9 94.5 52.8 12 26.7 99.1 111.1 61.3 13 26.5 99.1 91.6 61.5 14 26.5 98.9 152.8 62.5 15 19.1 98.3 134.1 54.2 16 13.1 98.0 104.6 57.7 17 15.4 98.0 150.6 51.8 18 15.4 98.0 151.4 51.6 19 50.7 99.1 106.2 68.7 20 50.8 99.1 99.4 68.6 21 50.3 99.1 97.2 69.0 22 50.2 99.0 144.7 67.3 23 51.1 98.9 92.3 61.4 24 50.8 99.1 104.0 68.6 25 50.9 99.1 91.6 68.6 26 38.8 98.6 150.1 70.7 27 39.2 98.9 156.0 70.4 28 27.5 98.0 112.7 62.3 29 30.7 98.0 150.1 59.9 30 30.8 98.0 150.5 60.2

The maintenance cost of the hydraulic dehydrator in 2013 is estimated to be 2.7 billion won (330-day operation standard), and the processing cost per 1 ton of sludge with 98.8% water content is about 1,534 won and the inflow sludge amount is 535 ton / day Water content 98.8%), the number of working days per year: 330 days

The rotary impact type drier is a rotary impact type dry and crusher for separating the supplied sewage sludge into fine particulate matter and moisture by a particle collision method by a high speed centrifugal force. As shown in FIG. 3A, rotation of the bar And 200 m / sec) and a vortex of a high-speed airflow. As shown in FIG. 3 (b), the moisture of the particle surface is separated and collided between the rotor and the wall surface and the upper plate (Fine drop), and as shown in Fig. 3C, the same operation is repeated from the new particle surface due to the pulverizing action of the particles (main action principle of reducing the water content).

≪ Example 2 >

Drying tests of sludge were carried out with a water content of 58.5 ~ 70.6% sludge.

Sludge Drying Test Results division input
(kg) Moisture content Time
(min) Amount of electricity
(kW) Before drying (%) after drying(%) One 150 58.6 13.6 21.9 42.84 2 150 70.6 18.4 22.8 52.94 3 261 60.0 14.3 27.0 64.61 4 30 58.5 12.8 4.5 5.51 5 360 60.3 14.5 34.8 125.28 6 240 68.0 16.3 28.5 82.23 7 300 66.4 15.2 42.0 102.42 8 240 67.7 14.4 33.0 102.42 9 720 70.2 15.5 85.5 343.77 10 150 62.1 13.4 24.0 54.26 11 210 68.5 12.5 25.5 57.45 12 210 65.0 13.9 27.0 60.09 13 300 68.4 11.4 36.0 82.02 14 150 67.5 11.5 21.0 46.50 15 240 63.4 13.5 24.9 54.45 16 90 64.9 12.0 12.3 21.42 17 150 67.5 13.4 22.5 46.23 18 150 66.6 15.1 21.0 39.24 19 150 62.8 10.5 21.0 41.25 20 240 67.0 16.2 26.1 62.40 21 450 62.7 12.7 61.2 156.45 22 180 59.5 10.8 28.5 60.93 23 180 65.3 13.6 25.5 52.74 24 150 70.4 15.9 22.5 54.33 25 180 68.6 14.0 24.0 63.18 26 240 70.1 15.2 34.2 106.20 27 150 69.5 13.7 20.4 60.15 28 300 64.9 13.3 31.5 81.93 29 150 64.7 13.5 20.4 50.64 30 120 65.8 14.1 15.0 48.21 31 150 62.4 11.6 20.4 34.50 32 270 61.4 12.0 30.0 82.32 33 360 63.3 13.2 43.8 137.43 34 150 66.7 15.4 18.6 50.94 35 120 65.3 15.3 17.1 33.00 36 120 61.6 11.8 15.0 35.22 37 210 64.0 13.7 30.6 76.50 38 240 65.4 13.5 32.4 74.31 39 90 68.1 14.6 12.0 25.59 40 150 67.0 16.1 18.9 63.72 41 240 66.2 13.5 33.6 79.92 42 330 64.0 13.0 42.0 130.68 43 180 66.9 13.1 25.5 70.11 44 180 62.2 12.7 21.0 67.89 45 240 64.8 13.2 35.6 93.93 46 150 63.9 13.6 16.5 39.15 47 120 69.4 14.9 17.1 28.56 48 270 67.1 16.5 39.6 100.77 49 300 66.0 14.5 41.4 118.92 50 210 65.7 15.2 27.3 52.77

The water content of the input sludge is 58.5 ~ 70.6%, and the water content of the sludge after drying is 10.5 ~ 18.4% and the average drying efficiency is 76.9%. The drying time of the sludge varies depending on the amount of input, but it is analyzed that it takes about 96.7 ~ 160.0min (average 132.4min) to dry 1 ton of sludge in general. The amount of power consumed to dry the sludge with a water content of 70% increases in proportion to the amount of input sludge, and an average power of 324.9 kW is obtained when drying 1 ton sludge with a moisture content of 10-15% or less.

The rotary impact type drier has a classifier in the chamber, so that the desired water content can be adjusted. When the speed of the sorter is increased, the water content is low and the particle size is small. If the speed is low, the opposite result can be obtained. Also, in the case of sludge, fine particles having a particle diameter of 100 to 2,000 mu m are used, and when the object is municipal waste, drying and crushing are carried out using a fiber.

(Municipal waste treatment process)

This process is to sort combustible wastes from municipal wastes, crush them with crushers, and then process the crushed materials into flammable waste with a water content of less than 10 ~ 15% and a calorific value of more than 5,500 kcal / kg using a rotary impact drier.

It is sufficient that the crusher has a crushing function without limitation, and the rotary impact type drier is the same as the drier of the sewage sludge disposal process. Therefore, in order to avoid duplication, A detailed description thereof will be omitted.

≪ Example 3 >

In the case of the exercise type dryer used in the rear stage of the crusher in this experiment, it is necessary to crush the municipal waste because the inlet of the dryer may be clogged when the waste is supplied without being crushed. In the crushing test, the loss of volume due to the reduction of pore volume occurs, but the weight is not reduced. Therefore, there is no difference between the amount of input and the amount of discharge, and the time required for power consumption and power consumption are proportional to each other.

Results of dismantling of municipal waste division Input (kg) Emissions (kg) Time required (min) Power (kW) One 360 360 42.0 3.810 2 180 180 18.0 1.863 3 420 420 45.0 4.554 4 240 240 30.0 1.487 5 240 240 28.8 2.400 6 120 120 15.0 0.993 7 300 300 37.5 3.450 8 360 360 39.0 3.750 9 210 210 25.2 2.016 10 150 150 15.0 1.650 11 210 210 22.5 1.950 12 270 270 27.0 2.649 13 120 120 12.6 1.230 14 300 300 25.5 2.940 15 360 360 34.5 3.909 16 150 150 15.9 1.413 17 210 210 24.0 1.896 18 210 210 24.9 2.151 19 300 300 34.5 2.445 20 180 180 21.0 1.626 21 150 150 13.2 1.722 22 150 150 11.4 1.470 23 240 240 19.5 2.133 24 300 300 34.5 2.715 25 150 150 11.4 1.500 26 300 300 23.1 2.589 27 270 270 20.4 2.565 28 240 240 28.5 2.517 29 180 180 18.0 1.719 30 180 180 16.5 1.671 31 150 150 16.5 1.485 32 150 150 12.0 1.284 33 300 300 24.0 2.751 34 210 210 16.5 2.124 35 150 150 10.2 1.338 36 270 270 24.3 2.382 37 240 240 24.0 2.145 38 240 240 19.5 2.199 39 180 180 15.0 1.491 40 240 240 22.5 2.085 41 150 150 9.0 1.287 42 300 300 22.5 3.162 43 180 180 15.0 1.485 44 210 210 15.9 2.037 45 210 210 18.3 1.704 46 150 150 11.4 1.485 47 300 300 23.7 2.559 48 240 240 21.0 2.505 49 150 150 11.4 1.266 50 330 330 25.5 2.754 51 45 45 8.1 0.504 52 90 90 9.0 0.960 53 120 120 12.0 1.269 54 150 150 18.6 1.680 55 180 180 20.7 1.980 56 135 135 15.0 1.560 57 240 240 30.0 2.376 58 180 180 21.0 1.965 59 180 180 20.4 1.920 60 120 120 14.4 1.320

The electric power consumption in the waste test of the present waste is 0.168 ~ 1.518 kW, which is proportional to the amount of crushing. The average amount of power required to crush 1 ton of waste is 9.69 kW.

<Example 4>

Waste Drying Test Results division Input (kg) Moisture content Time
(min) Amount of electricity
(kW) Before drying (%) after drying(%) One 120 15.7 8.0 10.5 32.40 2 150 39.1 15.2 13.5 60.84 3 129 25.0 6.1 16.5 44.70 4 129 29.1 5.7 15.9 41.65 5 153 24.9 11.1 15.0 47.42 6 180 34.8 14.3 18.0 56.96 7 261 34.8 14.3 25.8 83.84 8 279 59.6 13.9 27.9 117.63 9 255 59.0 14.5 27.0 106.43 10 300 48.0 14.7 33.9 106.43 11 150 38.8 11.3 13.5 42.30 12 240 29.5 7.1 22.5 63.93 13 180 41.7 10.3 15.9 45.18 14 150 35.0 9.3 15.0 47.49 15 150 35.0 13.5 12.9 41.85 16 120 41.2 12.9 10.5 35.40 17 240 41.2 9.4 22.5 54.99 18 150 37.7 7.7 13.5 43.05 19 210 34.5 7.3 15.0 54.90 20 240 39.6 10.8 21.0 69.00 21 150 40.5 9.5 10.5 34.50 22 150 40.5 8.4 12.0 39.00 23 240 40.5 8.5 20.4 66.90 24 300 35.3 7.8 31.5 102.33 25 150 47.8 11.5 13.2 45.30 26 300 38.1 7.0 25.8 96.54 27 270 41.7 7.9 24.0 93.39 28 240 41.7 9.5 19.5 77.40 29 180 39.3 10.0 21.0 53.52 30 180 38.5 7.6 15.0 57.36 31 150 30.7 7.7 12.0 42.15 32 150 30.7 7.3 12.0 43.80 33 300 33.6 9.1 25.8 89.64 34 210 32.7 8.8 16.5 60.18 35 150 35.0 8.8 13.2 42.36 36 270 31.5 8.1 23.4 82.29 37 240 37.7 7.5 18.6 74.85 38 240 36.9 8.6 19.5 71.22 39 180 37.4 9.0 75.9 55.92 40 240 40.0 10.3 74.3 77.85 41 150 39.1 11.9 69.6 44.34 42 300 41.2 11.0 73.3 91.20 43 180 40.9 9.5 76.8 55.17 44 210 38.8 8.7 77.6 67.38 45 210 35.4 9.4 73.4 62.64 46 150 33.9 7.5 77.9 49.26 47 300 32.1 10.3 67.9 108.15 48 240 33.7 9.9 70.6 70.89 49 150 34.5 7.1 79.4 47.43 50 330 33.6 7.3 78.3 103.98 51 150 43.5 10.5 75.9 45.90 52 150 46.2 11.9 74.2 48.69 53 180 40.6 9.7 76.1 51.60 54 180 42.3 10.6 74.9 52.68 55 210 38.8 11.3 70.9 54.63 56 240 38.6 9.1 76.4 55.50 57 270 37.7 10.5 72.1 60.90 58 300 41.5 12.4 70.1 75.69 59 330 45.3 11.2 75.3 74.01 60 360 43.0 12.8 70.2 85.68

The water content of the dry waste was 5.7 ~ 15.2%, and the drying efficiency was 49.0 ~ 81.6% (average 73.5%) compared with the input waste. The drying time required to reach the target water content was 3.5 ~ 11.3min according to the input amount and water content, and 70.0 ~ 127.9min (average 89.6min) was required for 1ton waste. The amount of electricity consumed to dry municipal wastes at a water content of 10 ~ 15% is increased in proportion to the amount of waste, etc., and it is 32.4 ~ 117.6 kW according to the amount of input. The average power consumption per 1 ton drying is 300.5 kW.

(Mixing process)

This process mixes the sludge crush having a water content of less than 10 to 15% prepared by the sewage sludge treatment process and the municipal waste treatment process with a flammable crush having a moisture content of less than 10 to 15% and a caloric value of 5,500 kcal / kg or more, The sludge and combustible lumps were mixed at a ratio of 4: 6 ~ 2: 8, and the compression molded pellets in the molding process described below had a calorific value of 4,700 ~ 4,924 kcal / kg, chlorine 0.94 ~ 1.1% wt, moisture 5.2 ~ 6.0% wt, 20.1 to 16.1 wt% of ash, and 0.1 to 0.02 wt% of sulfur.

&Lt; Example 5 >

The municipal solid waste generated by crushing municipal solid waste to an appropriate size was processed for the purpose of this experiment. According to the mixed ratio of sludge and waste, 4,1534,924 / m 2, 2.56.6% wt of water, 0.811.10% wt of chlorine and 0.022% of sulfur were obtained from the Korea Institute of Machinery and Materials. (20% wt) at above 5: 5 mixing ratio, and the amount of ash was 16.1 ~ 27.4% wt. .

Solid fuel molding test analysis result division Mixture of sludge and waste 2: 8 3: 7 4: 6 5: 5 6: 4 7: 3 8: 2 Low calorific value (kcal / kg) 4,924 4,814 4,700 4,368 4,350 4,205 4,153 Moisture (% wt.) 6.0 5.2 5.2 6.6 4.9 3.6 2.5 Chlorine (% wt.) 1.1 0.97 0.94 0.95 0.91 0.83 0.81 Sulfur (% wt.) 0.02 0.02 0.1 0.16 0.15 0.21 0.22 Ash (% wt.) 16.1 17.3 20.1 22.3 23.3 25.1 27.4 Mercury Not detected Not detected Not detected Not detected Not detected Not detected Not detected cadmium 4.95 4.72 4.97 3.77 3.53 4.72 3.90 lead 91.75 93.49 78.95 71.52 60.74 48.94 62.46 arsenic Not detected Not detected Not detected Not detected Not detected Not detected Not detected

On the other hand, the public sewage treatment facilities under Article 2 (9) of the Sewerage Act or the sewage treatment facilities under Article 2 (10) of the same Act or the water pollution prevention facilities according to Article 2 (12) of the Water Quality and Aquatic Ecosystem Conservation Act If the organic sludge (except for the sludge generated at the previous stage of the biological treatment of designated waste or manure) is processed to manufacture fuel,

Engineered fuels should not exceed 10 percent moisture content, 35 percent ash content (dry basis), 2 percent sulfur content (dry basis) and 40 mm diameter (round size). However, if the ash content exceeds 35 percent, it may exceed 35 percent if it can be used as a fuel in a thermal power plant.

In addition, the organic sludge recycled as fuel is tested according to the quality test and analytical method of the solid fuel product notified by the Minister of the Environment pursuant to Article 20-5 (3) of the Enforcement Regulation of the Act on the Promotion of Energy Conservation and Recycling ) Shall comply with the following criteria. Mercury: not more than 1.20 milligrams per kilogram, cadmium: not more than 9.0 milligrams per kilogram, lead: not more than 200.0 milligrams per kilogram, arsenic: not more than 13.0 milligrams per kilogram.

In this respect, when the sludge is converted into solid fuel, the calorific power is about 3,000 kcal / kg, which is not suitable for use as a main fuel in a power plant or a cement production facility. However, the present invention is suitable for the standards of mercury, cadmium, lead and arsenic , And more than 20% of wastes showed a calorific value of more than 4,000kcal / kg. Therefore, it can be used sufficiently as main fuel in the use facility. Also, moisture, chlorine, and sulfur except calorific value are suitable for solid fuel quality standards. However, in the case of ash, the higher the mixing ratio of the sludge is, the higher the mixing ratio is not suitable for the quality standard of ash (20wt.%) , To meet the standard as solid fuel, the mixing ratio of the sludge should be adjusted to 40% or less so as to solidify the fuel The.

(Molding step)

In this process, a mixture of the sludge crushing material and the combustible crushing material mixed by the crushing material mixing step is compression-molded into a pellet by a molding machine. The molding machine can be a ring dice type or a wheel dice type, The contact area with the raw material is 50% lower than that of the ring dice and the lifetime is prolonged. As a result, since the production amount is low and the electricity consumption is low, it is more economical to mold the wheel dice system. A molding machine capable of compressing and molding the pellet without receiving it is acceptable.

&Lt; Example 6 >

The energy required for solid fuel molding is only the electric power required for driving the motor, and other additives and auxiliaries are not used. The power required for molding is determined by the amount of injection for molding, regardless of the ratio of high water content, low moisture content and mixed fuel.

Power consumption (㎾) due to water content reduction during molding division Input (kg) Moisture content Time
(min) Power consumption
(kW) Before molding (%) After molding (%) One 300 15 1.5 <10 18.9 26.91 2 240 15 1.5 <10 14.7 16.59 3 666 15 1.5 <10 33.6 37.05 4 900 15 1.5 <10 28.7 98.64 5 282 15 1.5 <10 13.5 22.90 6 102 15 1.5 <10 4.2 12.96 7 117 15 1.5 <10 10.5 15.33 8 90 15 1.5 <10 6.3 9.84 9 90 15 1.5 <10 7.2 8.04 10 120 15 1.5 <10 6.3 8.28 11 120 15 1.5 <10 7.8 7.08 12 120 15 1.5 <10 6.9 8.97 13 120 15 1.5 <10 6.6 10.26 14 90 15 1.5 <10 4.8 9.57 15 90 15 1.5 <10 5.1 9.18 16 240 15 1.5 <10 11.7 19.65 17 150 15 1.5 <10 9.6 12.60 18 300 15 1.5 <10 18.3 23.10 19 210 15 1.5 <10 13.8 12.00 20 120 15 1.5 <10 8.7 6.60 21 120 15 1.5 <10 9.3 6.90 22 120 15 1.5 <10 8.7 7.80 23 90 15 1.5 <10 5.7 6.00 24 600 15 1.5 <10 29.4 41.25 25 450 15 1.5 <10 20.4 31.83 26 180 15 1.5 <10 15.3 17.40 27 180 15 1.5 <10 11.4 13.29 28 120 15 1.5 <10 6.9 8.70 29 360 15 1.5 <10 19.2 31.65 30 300 15 1.5 <10 16.5 24.75 31 300 15 1.5 <10 18.3 30.93 32 150 15 1.5 <10 9.6 9.51 33 120 15 1.5 <10 8.4 7.32 34 300 15 1.5 <10 16.5 23.94 35 270 15 1.5 <10 16.2 19.14 36 270 15 1.5 <10 14.7 17.61 37 150 15 1.5 <10 8.4 10.35 38 270 15 1.5 <10 15.3 18.09 39 120 15 1.5 <10 13.8 7.65 40 120 15 1.5 <10 8.4 9.33 41 120 15 1.5 <10 6.3 7.44 42 270 15 1.5 <10 14.1 25.83 43 270 15 1.5 <10 15.9 21.12 44 270 15 1.5 <10 15.3 20.70 45 90 15 1.5 <10 5.7 6.00 46 450 15 1.5 <10 22.5 39.42 47 540 15 1.5 <10 21.9 44.55 48 360 15 1.5 <10 19.8 36.39 49 210 15 1.5 <10 12.6 18.09 50 270 15 1.5 <10 14.4 18.30

Molding of mixed fuels only requires power, which is power dependent. The required power is proportional to the increase of the amount of molding and it takes 6.00 ~ 98.64㎾ in this experiment. The average power consumption per ton of raw material was calculated as 79.6 kW. The time required for molding of this molding machine was analyzed to be 31.8 ~ 115.0 min to form 1 ton of mixed sample. As shown in FIG. 4, the size of the solid fuel that has been molded is 22 mm in width and 22 mm in length, which is less than 50 mm, and the length is 100 mm or less.

On the other hand, the cost of energy consumed through the sewage sludge treatment process, the municipal waste treatment process, the crushing material mixing process, and the molding process according to the present invention is as follows .

(Costs for general sewage sludge dry fueling)

① Dehydration cost (excluding consumption of medicine)

- Power consumption of centrifugal dehydrator: 64kW / 30ton (16hr / ㅧ 2 ㅧ 2kwh)

- 100ton ㅧ 60㎾ / 30ton ㅧ 84.8 won / ㎾ = 18,091 won

② Drying Cost

- Drying Calories Required Unit Price: 750,000kcal / ton.H ₂ O

- 750,000㎾ / ton.H ₂ O ㅧ 3.889ton ㅧ 21.6 Yuan / MJ = 263,768 Yuan

③ Dehydration cost + drying cost = 18,091 won + 263,768 won = 281,859 won

(Cost required for solidification of sewage sludge and municipal solid waste according to the present invention)

① Dehydration cost (excluding consumption of medicine)

- Power consumption: 4.23㎾ / ton (average of annual consumption)

- 100ton ㅧ 4.23㎾ / ton ㅧ 84.8 Won / ㎾ = 35,870 Won

② Drying Cost

- Power consumption: 324.9㎾ / ton (experimental data for this time)

- 2.86ton ㅧ 324.9 ㎾ / ton ㅧ 84.8 / / ㎾ = 78,797 원

③ Molding cost

- Power consumption: 79.6㎾ / ton (experimental value of this session)

- 1.18ton ㅧ 79.6㎾ / ton ㅧ 84.8 Won / ㎾ = 7,965 Won

④ Total cost: Dehydration cost + drying cost + molding cost = 122,160 won

As a result of the analysis, it is expected that when the simple energy consumption costs without various factors are simply compared, the application technology of the present invention is expected to save energy cost of 50% or more compared to the existing life style.

As described above, the present invention provides a method for producing a solid fuel by mixing municipal waste with sewage sludge, having a calorific value higher than that of a national standard for use as a main fuel at a low cost and having a chlorine, moisture, ash, It is possible to manufacture the pellet type solid fuel at a low cost and high efficiency by reducing the amount of the sludge to below the reference value while meeting the solid fuel quality standard according to the quality of the sludge, It has a profit structure that sells fuel, and it is possible to secure economic efficiency and price competitiveness by reducing sludge treatment cost according to the sludge treatment facility.

While the present invention has been particularly shown and described with reference to preferred embodiments thereof, it is to be understood that the invention is not to be limited to the details thereof, The range is determined and limited. It will be apparent to those skilled in the art that various changes and modifications can be made by those skilled in the art without departing from the scope of the present invention.

Claims (1)

Sewage sludge treatment process of dehydrating sewage sludge having a water content of 97 ~ 99% by using a squeezing type dehydrator at a water content of 60 ~ 70% and then processing into sludge disintegration with a moisture content of less than 10 ~ 15% ;
A municipal waste treatment process in which flammable waste is selected from municipal wastes, crushed by a crusher, and processed into a flammable waste having a calorific value of 5,500 kcal / kg or more with a moisture content of less than 10 to 15% by using a rotary impact type drier;
A sludge disintegration step of mixing a sludge crush having a water content of less than 10 to 15% and a combustible crush having a calorific value of less than 10 to 15% and having a calorific value of 5,500 kcal / kg or more prepared through the sewage sludge treatment process and the municipal waste treatment process;
And a molding step of compressing and molding a mixture of the sludge crushing material and the combustible crushing material mixed in the crushing material mixing step into a pellet form by a molding machine,
The sludge crusher and the combustible crusher are mixed at a ratio of 4: 6 to 2: 8 in the crushing and mixing process. The pellets thus compression-molded in the molding process have a calorific value of 4,700 to 4,924 kcal / kg, chlorine 0.94 to 1.1% Wherein the content of the sludge is in the range of 5.2 to 6.0 wt%, 20.1 to 16.1 wt% of ash, and 0.1 to 0.02 wt% of sulfur.

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