KR100991483B1

KR100991483B1 - Biomass drying method using microwave drying device & oil

Info

Publication number: KR100991483B1
Application number: KR1020100017989A
Authority: KR
Inventors: 손민일
Original assignee: (주)레띠즈에너지
Priority date: 2010-02-26
Filing date: 2010-02-26
Publication date: 2010-11-04

Abstract

The present invention relates to a method for drying biomass using microwaves and thermoelectric medium oil, and more specifically, biomass (eg, grains, wood, manure, food waste, sewage and paper sludge, etc.) using microwaves. By drying, but mixed with the thermoelectric fluid and dried to improve the drying efficiency by increasing the drying speed per hour than the conventional method using only microwaves to shorten the overall drying time. In addition, the biomass dried by the present drying method may be extracted or milked (or deoiled) to separate the thermoelectric oil contained in the biomass and recycled as fuel.

Description

Biomass Drying Method Using Microwave Drying Device ＆ Oil}

The present invention relates to a method for drying biomass using microwaves and thermoelectric medium oils, and more particularly, by mixing biomass and thermoelectric medium oils and drying them in a microwave to drastically increase the drying speed. It is a new drying method with improved drying efficiency than drying method. Biomass dried using this technology can also be recycled as fuel on its own or through separate secondary processing (extraction-distillation by solvent, milking by compression, deoiling by centrifugation). In addition, the application of this technology can more effectively eliminate pathogens, pests and odors in sludge at the same time.

As energy and environmental issues intensify, interest in biomass, which can replace fossil fuel resources, is rapidly increasing. In particular, with the entry into force of the Kyoto Protocol, governments and companies around the world are taking a quick step in securing alternative technologies and resources to reduce greenhouse gases. Among these, biomass resources such as garbage, grains and agricultural by-products, which are commonly found around us, are emerging as a viable alternative to solve energy and environmental problems. Biomass is a representative resource that human beings have been using for a long time as food, energy, building materials, household goods, such as grain, wood, manure, food waste, sewage and paper sludge, but it is valued by inexpensive and convenient fossil fuels. I haven't received it. However, biomass is considered to have the potential to replace various petrochemical-based products as well as renewable energy. There are many types of biomass, from microorganisms to plants and animals, by-products of various human activities, or garbage. Specific examples include cereals, wood (wastewood, felling, etc.), animal manure, food waste, and organic sewage sludge. Among them, organic sludge, such as paper sludge and sewage sludge, has attracted attention for its recycling.

Paper sludge and sewage sludge are produced in the form of dehydrated cake with 60 ~ 85% water content in the final process and contain more than 30 ~ 70% of organic matter based on solid content except water. Therefore, sewage sludge and paper sludge have high calorific value of about 2,000kcal / kg ~ 4,000kcal / kg. Therefore, such organic sludge is classified as a low carbon fuel, and in Korea, it is generated about 6.43 million tons (as of 2007). The government banned dumping of organic sludge by sea until February 2011, and announced the principle of land treatment through recycling. However, organic sludge has a high water content and is excluded from the general incineration plant treatment, so landfill treatment is common. However, the treatment of organic sludge through landfill has been a problem due to secondary pollution of groundwater due to leachate, ground weakening, securing landfill area.

In particular, in order to fuel organic sludge, two major obstacles must be overcome. First, since most organic sludges account for more than 60% of moisture, development of low cost and high efficiency drying technology is the biggest technical task for fueling. Second, the chemical properties of organic sludge are irregular according to the type of organic sludge or the characteristics of the discharge source, which acts as a barrier to maintaining the calorific value of the final recycled fuel using the same.

Various methods of drying organic sludge for fueling or incineration of organic sludge have been proposed at present, and the general drying apparatus used in the industrial site is heated drying method, hot air drying method, Various methods such as power drying, kiln drying, refrigerant compression drying, etc. are mobilized to dry according to the equivalent amount and purpose of use. However, the drying method and the kiln drying method by heating have a problem that not only the drying efficiency is significantly reduced due to a long drying time, but also a large amount of fuel is consumed due to drying and the treatment cost increases. In addition, the hot air drying apparatus for drying by spraying hot gas has a problem that the sludge particles are scattered by the strong injection pressure of the gas to be discharged to the outside while polluting the atmosphere. As a supplement to the above problems, there is a oil-in-water drying method and a drying method using a microwave.

As a method for drying in water, Japanese Laid-Open Patent Publication No. 56-62891 discloses a method for producing a solid fuel in which organic sludge, waste oil and plastic waste are mixed and molded, and then reduced in water content by thermal drying. -214173 discloses a liquid or granular fuel prepared by adding waste oil such as waste paper diapers to heated vegetable oil, evaporating water, neutralizing and removing hydrogen chloride gas contained in the waste, and then adding waste oil. It is. Korean Patent Registration No. 0349218 discloses a method of supplying sludge and oil to a mixing tank and then drying the mixture by heating and stirring under vacuum. Korean Patent Publication No. 10-2009-0029385 discloses organic sludge using oil waste. A method of drying at a high temperature is provided. However, the above method has a structure in which a large amount of oil is used to increase the drying effect. The oil consumption or recovery cost is high, and the apparatus is complicated and requires a large amount of space in order to increase the size of the oil. It takes a long time to take. In addition, when dried or molded in a state in which waste oil and organic sludge containing a large amount of water are mixed, evaporated water passes through the oil film of waste oil to generate enormous amounts of bubbles. Accordingly, extrusion (compression) is difficult due to the generation of bubbles in the extrusion (compression) molding process, the moldability (shape retention) of the product (solid fuel) is deteriorated, and voids are formed by the bubbles after the drying process, resulting in high strength. There is a problem of deterioration.

The microwave drying method, which is proposed as another new drying method, is a method of drying using microwave called high frequency RPM and is evaluated as the most efficient drying method. In particular, the “microwave dryer” of Korean Utility Model Registration No. 20-0391583, which is recently applied for patents using microwave drying technology, provides a method of collecting waste foods from home or restaurant, which is the origin of waste foods, and drying them by itself. In addition, Korean Patent Registration No. 10-0541159, "Sewage sludge treatment apparatus and method using microwave and heating" is a sewage sludge treatment apparatus having a dryer for solubilizing and reducing the sewage sludge generated in the sewage treatment plant. A microwave generator for generating microwaves and a hot air heater for heating the inside of the dryer to a predetermined temperature; A sewage sludge treatment apparatus and a treatment method using the same are provided, wherein the sewage sludge introduced into the dryer is decomposed, solubilized and reduced by the combination of microwave irradiation from a microwave generator and heating from a hot air heater. In addition, Korean Patent No. 10-0836664, "Microwave Sludge Drying Device Using Waste Heat of Blower as Hot Air and Drying Method Using It," shows that the existing aeration tank air supply blower using sludge of waste water in microwave and sewage treatment plants. By reusing and drying high-temperature discharged air, the sludge can be dried quickly and energy can be saved.In addition, the microwave sludge drying device using the waste heat of the blower with low installation cost as a hot air and the installation method using the same are presented. In the “Sludge Drying Method and Apparatus” of Korean Patent Registration No. 10-0539413, the sludge to be dried is supplied to one end of a plurality of screws that are rotated in parallel so that the pitches of the rotating blades are staggered from each other and rotated. Rotate Thereby allowing the sludge to be transported to the other end of the screw by a rotary blade, and actuating the magnetrons installed continuously at predetermined intervals in the conveying direction of the sludge so that microwaves act in the screw direction, and are disposed continuously between the magnetrons. By operating a near-infrared lamp installed so that near-infrared rays act in the direction of the screw, a method of heating and drying the sludge with microwaves and near-infrared rays while grinding, stirring and transferring the sludge with the plurality of screws is proposed.

However, the conventional patent technology proposed as described above has a slight effect of improvement compared to the general microwave drying method. For example, "Sewage sludge treatment apparatus and method using microwave and heating" of Republic of Korea Patent Registration No. 10-0541159 and "Microwave sludge drying apparatus using the waste heat of the blower as hot air and drying method using the same" of Republic of Korea Patent Registration No. 10-0836664 ”Is basically the same principle that combines the advantages of the microwave method and the hot air drying method, and simply improves the drying environment in the microwave dryer by using external hot air to increase the drying effect. Because it does not have a direct effect on, the improvement effect is inevitable. In addition, the “Sludge Drying Method and Apparatus” of Korean Patent Registration No. 0939413 is a drying device using a combination of near-infrared and microwave methods, which aims to effectively dry the combined water present in the sludge, but it has little effect on energy input. In addition, when the screw is used, the dry matter is dried in the dryer and the strength is increased, and there are inherent problems such as deterioration in efficiency due to dust and damage to the screw blades at the rear end of the dryer and odor. In addition, the microwave-related drying method of the patents proposed in the prior art also has a fundamental countermeasure for maintaining a uniform calorific value, which is the second task of fueling organic sludge.

Biomass is composed of organic cells, etc. due to the nature of its production process, and the moisture contained in the sludge penetrates deeply between cells and cells, and particles and particles, so that the moisture content is more than 60%, which is the energy of biomass. It is a big stumbling block to anger. In other words, the water contained in the biomass can be classified into free water existing on the surface and bound water present in the core. Especially, the bound water is the surface water affected by the surface according to the relationship with the particle surface. ) And bound water by intracellular water or hydrate, which is due to the difference in binding energy. The major chemical components of biomass consist mainly of polar substances, and the same polar moisture is strongly bound to the polar substances in biomass, so it is difficult to remove them by mechanical dehydration method, which requires thermal and chemical pretreatment. This is of primary interest in the dehydration process. In general, surface water and bonding water are called the theoretical limits of mechanical dehydration.

Therefore, it is necessary to find an effective method for effective drying of biomass.

In addition, since the chemical properties are irregular depending on the type or the characteristics of the discharge source, the calorific value is also irregular, which makes biomass fueling difficult. In addition, there is a need to solve dust and odor problems of biomass.

The present invention has been devised to solve the above problems, and by employing a microwave drying method for effective drying of the biomass, it is possible to effectively dry the biomass having a high moisture content by using a thermoelectric oil at the same time. In addition, by adjusting the content of the thermoelectric oil remaining in the biomass during the drying process to be uniform, it is possible to achieve a dried biomass fuelization. In addition, the use of thermoelectric fluid as a liquid in the drying process can solve the dust problem, and the odor can be solved by burning in the drying process.

It is economical to process biomass with high moisture content through thermoelectric medium oil and March microwave drying device in the process using only microwave, hot air drying method or drying method in water. In addition, since 5-20% of the thermoelectric medium oil remains in the dried biomass, the dried biomass can be recycled as a fuel by uniformizing the residual amount of the thermoelectric medium oil to a certain level. It also solved the big problem of biomass dust and odor.

1 is a drying process diagram according to a first exemplary embodiment of the present invention.
2 is a drying process diagram according to a second exemplary embodiment of the present invention.
3 is a schematic view showing an embodiment of a drying system used in the present invention.
4 is a schematic view showing another embodiment of a drying system used in the present invention.

The present invention is to dry the biomass, such as grain, wood, manure, food waste, sewage and paper sludge, using a microwave, but drying by using a thermoelectric fluid in combination to increase the drying speed per hour than the drying method using only microwaves The present invention relates to a drying method of biomass having improved drying efficiency by shortening the time.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

1 is a drying process diagram according to a first embodiment of the present invention, Figure 2 is a drying process diagram according to a second embodiment of the present invention, Figure 3 is a schematic view showing a drying system used in the first embodiment 4 is a schematic diagram showing a drying system used in the second embodiment. Hereinafter, a drying method of the biomass will be described with reference to the drawings.

First, as shown in FIG. 1, the biomass and the thermoelectric medium oil are mixed together in the mixer 20, and the mixture is put into the grinder 10 and pulverized into 30 to 150 mesh. However, as shown in FIG. 2, only the biomass may be put into the grinder 10 to be ground. The biomass may be any one or two or more of grain, wood, manure, food waste, paper sludge, sewage sludge,

The thermoelectric medium oil may be one or more selected from mineral oils (such as fuel oils such as petroleum, kerosene, and diesel oil), vegetable oils, and animal oils. In addition, the thermoelectric medium oil of the present invention includes waste oil. More specifically, waste mineral oils such as automobile oil, ship oil, insulation oil, gear oil, turbine oil, and waste vegetable oils such as soybean oil, grape seed oil, corn oil, palm oil, sunflower oil, and wastes such as cattle, pigs, chickens, and fish It may be selected from animal oils. Preferably, the thermoelectric medium oil may be a mixture of one or two selected from the group consisting of waste cooking oil, waste vehicle oil, waste ship oil, waste insulating oil, waste fish oil and waste turbine oil, and the thermoelectric medium oil storage tank 30. Stored in and then supplied.

The thermoelectric medium oil is able to remove the moisture in the biomass against the non-polar thermoelectric oil by the polarized water contained in the biomass to remove the water more effectively by the repulsive force between the polar and the nonpolar, and also by the osmotic phenomenon of the cell membrane Can be removed effectively. In addition, the heat energy is easily transferred to the water due to the sensible heat effect caused by the non-thermal difference between the thermoelectric medium oil and the water, thereby quickly and effectively removing the bound water. Preheating to 50 ~ 250 ℃ before mixing thermoelectric medium oil can shorten the time until the biomass is heated to a temperature where the water in the biomass can evaporate after being put into the microwave device. You can. In this case, the mixing ratio of biomass and thermoelectric medium oil is preferably 1: 0.02 to 1.5. If the content of the thermoelectric medium oil is too low, heat transfer between the solid particles may be delayed. If the content of the thermoelectric medium oil is too high, the energy efficiency may be reduced, and the capacity of the separator may be increased when the thermoelectric medium oil is separated. When mixing the biomass and thermoelectric medium oil may be given ultrasonic waves so that the dispersion can be uniform. That is, in the mixer 20, the biomass and the thermoelectric medium oil may be stirred and the ultrasonic wave may be applied.

As shown in FIG. 1, when the biomass and the thermoelectric medium oil are mixed and pulverized, the pulverized mixture of the biomass and the thermoelectric medium oil is transferred to the microwave drying apparatus 40 and dried.

However, when only biomass is pulverized, as shown in FIG. 2, the pulverized biomass and thermoelectric medium oil are respectively transferred to the microwave drying apparatus 40 and dried.

The microwave drying apparatus 40 includes a hopper 41 for injecting a mixture of the biomass and the thermoelectric fluid as shown in FIG. 3; and a microwave generator 42 for generating microwaves; Anti-bubble storage tank 43 for storing the anti-bubble; Antifoam sprayer 44 for spraying antifoam; Steam discharge device 45 for discharging the steam generated during the drying process; A steam outlet 46 for discharging the steam to the outside of the microwave drying apparatus 40; A steam transfer pipe 47 for transferring the discharged steam to the condenser 60; A conveyor belt 48 for conveying a mixture of biomass and thermoelectric medium oil; And a biomass outlet 49 for discharging the dried biomass to the thermoelectric medium separator 50. However, when the biomass and the thermoelectric medium oil are respectively input, as shown in FIG. 4, the thermoelectric medium oil inlet 33 through which the thermoelectric medium oil is introduced is formed separately.

Facilities other than the microwave drying apparatus 40 include a grinder 10, a mixer 20, a thermoelectric fluid storage tank 30 for storing thermoelectric fluid, and a thermoelectric fluid supplied from the thermoelectric fluid storage tank 30. Heater 31 for heating the water, the steam discharged during the drying process is collected through the heater 31 to condense into a mixture of water and oil, while condensing the non-condensed gas to the direct fire (70) 60 ), Separating the mixture of condensed water and oil (thermoelectric medium oil) collected from the condenser into water and oil to discharge the water to the outside and oil to the thermoelectric medium oil storage tank (30), the oil and water separator (71), Thermoelectric medium oil storage tank by separating the thermoelectric medium oil from the non-condensing non-condensing gas (odor) sent from the condenser 60 and the biomass dried and discharged from the microwave drying apparatus 40 ( 30) sent into thermoelectric A cheyu separator 50.

The mixture of biomass and thermoelectric medium oil injected into the microwave drying apparatus 40 or the biomass and thermoelectric medium oil respectively added to the microwave drying apparatus 40 are heated to 80 to 300 ° C. by the microwave drying apparatus 40, wherein the thermoelectric medium oil is bio The free water of the mass surface and the combined water of the core act in the microwave drying apparatus 40 to be more easily removed.

In the heating process, water vapor is generated as the water is evaporated from the biomass and the thermoelectric medium oil, and the generated steam is collected by the steam collecting device 45 and then the microwave drying device 40 through the steam outlet 46. ) It is discharged to the outside. However, the steam generated at this time has a latent heat, and if used well, the temperature of the thermoelectric fluid can be increased. Therefore, in the present invention, the discharged steam is transferred to the heater 31 through the steam transfer pipe 47 connected to the steam outlet 46, and then heated to 100 ~ 200 ℃ in the heater 31, the condenser Are transferred to 60. The water vapor conveyed to the condenser 60 is separated into a small amount of uncondensed gas such as a thermoelectric oil component and a liquid vapor, and the water vapor of the liquid phase is transferred to an oil / water separator 71 to be separated into water and thermoelectric medium oil. The discharged thermoelectric medium oil is supplied to the thermoelectric medium storage tank 30 and reused. At this time, since the thermoelectric medium oil supplied to the thermoelectric medium oil storage tank 30 still has a high temperature of 100 to 200 ° C., the thermoelectric medium oil storage tank 30 is stored in the thermoelectric medium oil storage tank 30 only by utilizing the discharged steam. The temperature of the thermoelectric medium oil may be increased by 50 ° C or more. On the other hand, the non-condensation gas thermoelectric medium oil component is transferred to the incineration furnace 70 to be incinerated to remove odors inevitably generated during the drying process of the biomass.

On the other hand, the higher the temperature of the thermoelectric medium oil may have the effect of increasing the water evaporation rate in the microwave drying apparatus 40 and at the same time increase the energy efficiency. Therefore, it is necessary to raise the temperature of the thermoelectric medium oil by heating it before mixing the thermoelectric medium oil with the biomass. Therefore, when the thermoelectric medium oil stored in the thermoelectric medium oil storage tank 30 is mixed with the biomass or immediately put into the microwave drying apparatus 40, the temperature of the thermoelectric medium oil is controlled by heating the heater 31 beforehand. It was possible to increase to 250 ℃.

At this time, a large amount of bubbles can be generated in the microwave drying apparatus 40 by the generated steam, the bubbles generated in this way adversely affects the subsequent steps as well as the drying step. That is, a large amount of bubbles are generated at the interface (surface) and the inside of the thermoelectric medium oil introduced into the microwave drying apparatus 40 by the evaporation of water vapor, and the generated bubbles block the steam outlet 46 or the thermoelectric medium oil. Covers the interface and prevents the evaporation of water vapor. In addition, the generated bubbles may form voids when fuel is manufactured using the dried biomass, thereby lowering mechanical properties (strength).

Accordingly, in the heating process, bubbles should not be generated.

To this end, in the heating process, the biomass is introduced into the microwave drying apparatus 40 together with the thermoelectric medium oil, and heated to dry, but the microwave drying apparatus so as not to generate bubbles by the steam generated in the drying process. (40) should be carried out by spraying a bubble inhibitor. Therefore, by installing the bubble inhibitor nebulizer 44 inside the microwave drying apparatus 40 to be sprayed by receiving the anti-foaming agent from the bubble inhibitor storage tank 43 installed outside the microwave drying apparatus 40. At this time, the bubble inhibitor spray amount is preferably 0.2 ~ 5 mL / sec (sec).

The foam inhibitor includes a liquid or particulate as capable of suppressing the generated bubbles. The bubble inhibitor preferably contains alcohol. For example, the bubble inhibitor may use an aqueous solution containing a lower alcohol. In this case, the alcohol is one or a mixture of two or more selected from the group consisting of methyl alcohol, ethyl alcohol, propyl alcohol and butyl alcohol. In addition, the foam inhibitor is decanoic acid (lauric acid), lauric acid (lauric acid), mystic acid (myristic acid), palmitic acid (palmitic acid), stearic acid (stearic acid), oleic acid (oleic acid) Selected from the group consisting of mineral oil, oxystearine, dimethyl polysiloxane, silicon dioxide, sorbitan monostearate, and silicone resin One or a mixture of two or more.

At this time, it is better to give ultrasonic vibration to the microwave drying apparatus 40 by using an ultrasonic generator (not shown). That is, it is good to spray the bubble inhibitor to the microwave drying device 40 and at the same time to give ultrasonic vibration and heating. When the ultrasonic vibration is imparted in this manner, the bubble suppression efficiency is increased, and the mixing of the raw materials can be increased.

Therefore, the moisture contained in the biomass is removed during the drying process, so that the moisture content is 30% or less, specifically 0.01-30%. The time it takes for the water content to reach 30% or less depends on the quantity of biomass to be dried and the water content. Therefore, when the moisture content is 70%, it takes 5 to 30 minutes when the quantity of biomass is less than 1 ton, but it takes 2 to 5 hours when it is more than 1,000 tons.

In addition, the present heating process includes batch type and continuous type, preferably continuous type. At this time, as shown in Figure 3, so that the continuous process is possible inside the microwave drying apparatus 40, the conveying means for conveying the biomass and thermoelectric fluid, that is, the conveyor belt 48 is built in the hopper ( 41) The biomass introduced into the microwave drying apparatus 40 through the conveyor belt 48 is dried by the microwave while being transported on the conveyor belt 48 and then transferred to the thermoelectric fluid separator 50 through the outlet 49 for deoiling. The thermoelectric oil and the biomass are separated.

In this case, deoiling does not mean complete deoiling. That is, even after the deoiling process, a small amount of thermoelectric oil remains in the biomass. The thermoelectric oil component remaining in the biomass increases the calorific value when the biomass is manufactured as a fuel. In particular, in order to make the calorific value of fuel uniform, the amount of thermoelectric oil remaining in the biomass may be uniformly adjusted by adjusting the deoiling amount of the thermoelectric medium oil.

The method for separating the thermoelectric medium oil from the thermoelectric medium oil separator 50 includes gravity filtration (filtration network), centrifugal separation, roll type, and the like, and a common dehydrator, for example, a centrifugal dehydrator or a belt press. It may be by. The thermoelectric medium oil separated from the biomass is transferred to the thermoelectric medium oil storage tank 30 through the thermoelectric medium oil transfer pipe 51 and reused.

On the other hand, a method using a vacuum or hot air of 70 ~ 200 ℃ in the drying process by the microwave drying apparatus 40 can be performed in parallel. Such hot air and vacuum drying may be omitted as optional.

Hereinafter, it demonstrates by an experimental example in order to make this invention clearer. The following experimental examples are illustrative, and are provided only to assist in understanding the present invention, and the technical scope of the present invention is not limited thereto.

In the following experimental example, sewage sludge and papermaking sludge were used as biomass, and waste oil was used as thermoelectric medium oil. Therefore, it is necessary to study the composition of waste oil and the characteristics of paper sludge discharged by each paper company.

[Table 1] is the result of the component investigation according to the type of waste oil, [Table 2] is the result of the component investigation of paper sludge for each paper production item.

[Results of Component Investigation According to Type of Waste Oil] Item Type of waste oil Automotive oil Ship oil Insulation oil Gear oil Turbine oil Residual carbon (wt%) 1.43 0.66 0.09 0.05 0.05 Moisture and Sediment (Vol%) 0.04 8.0 - - - Ash (% by weight) 0.664 0.603 0.09 0.044 0.044 Sulfur (% by weight) 0.26-0.35 0.81 0.54 0.032 0.004 Heavy metals (mg / kg) Cd and its compounds One One One Less than 1 One Pb and its compounds Not detected Less than 1 One 8 One Cr and its compounds Not detected One One Less than 1 One As and its compounds Not detected Less than 1 Less than 0.01 Less than 1 Less than 1

As shown in [Table 1], since the sulfur content varies depending on the type of waste oil, the fuel must have a sulfur content condition (based on the weight of sulfur in the exhaust materials except moisture during combustion: 0.6 wt% or less). It should be mixed in consideration of waste oil type and sulfur content.

[Characteristics of Sludge Discharge by Paper Products]
Paper type Sludge content
(weight%) Others (minerals, etc.)
(weight%) Ash
(weight%) Cellulose
(cellulose)
(weight%) Paper 21.87 25.05 22.79 30.29 Newsprint Paper
(News print paper) 28.60 17.86 22.32 31.22 Kraft paper
(Kraft paper) 14.86 18.45 10.55 56.14 Wood Free Paper
(Woodfree paper) 5.79 9.49 57.70 27.02 Chengshu
(Tissues) 31.70 13.55 25.98 28.77 Etc 8.14 27.49 32.04 32.33 Average 20.75 17.55 25.21 36.49

[Characteristics of Sludge Discharged by Sewage Treatment Plant] Description
Moisture (% by weight) Volatility
(weight%) Fixed carbon
(weight%) ashes
(weight%) Calorific value
(cal / g, HHV) S establishment 73.4 19.1 0.42 6.9 2966 N1 Office 74.8 18.7 0.62 5.7 3132 N2 Office 78.8 15.1 0.91 5.1 3942 J1 Office 71.2 19.0 0.61 9.1 2765 J2 Office 74.1 16.7 0.72 8.3 2848

The solid content of the paper sludge indicates the degree of dehydration. The more the dehydration is progressed, the easier it is to transport and other subsequent treatments. In addition, the ash content of paper sludge discharged from the paper mill depends on various mineral fillers such as talc, kaolin, and calcium carbonate used in the manufacture of paper. In addition, the moisture content of the paper sludge was measured to determine the moisture content, it was found that the paper sludge discharged from the paper mill contains an average of 27% by weight of pure paper sludge and 73% by weight of water.

The organic matter content and composition of sewage sludge varies depending on the sewage inflow method, the presence of extinguishing process, and the source of sewage (household sewage, factory wastewater, livestock wastewater, etc.).

In order to utilize such sludge, the drying process requires the most cost and time, so sewage sludge and paper sludge are applied to prove the progress of this technology through comparison with the existing drying process and to apply the technology in an optimized state in the field. The following experiments were conducted to find out the optimum mixing ratio of each and thermoelectric fluids, the optimum input method of thermoelectric fluids for sewage sludge and paper sludge, and the optimum thickness of sewage sludge and paper sludge in microwave equipment. In the following examples, the test results of sewage sludge, paper sludge, and mixtures of paper sludge and sewage sludge tend to be almost the same, so only the results of paper sludge will be seen in this experimental example.

[ room Hum Yes ]

Experiment 1) Comparison of drying efficiency and energy efficiency by drying method

First, 100 g of paper sludge having 60% moisture content was prepared as it is discharged from a factory that mainly produces woodfree paper. Then, the paper sludge and the thermoelectric medium oil were mixed 1: 1, and then pulverized into 100 mesh to measure the water evaporation with time in a drying method in water. The paper sludge and the thermoelectric medium oil were mixed at 2: 1 and 100 mesh. After grinding, it was put in a microwave apparatus and the amount of water evaporated over time was measured. In addition, only 100 g of the papermaking sludge without thermoelectric oil was pulverized into 100 mesh, and then put into a microwave apparatus, and the amount of water evaporated over time was measured to compare the drying method using the microwave apparatus using the oil drying method and the thermoelectric medium. At this time, bubbles were generated by vapor evaporation, and it was found that the bubbles were suppressed by spraying the ethyl alcohol aqueous solution.

[Moisture evaporation per hour according to drying method] time Dry way Dry in oil MW drying Thermoelectric Medium MW Drying 0 0.00 0.00 0.00 2 0.60 8.20 5.17 4 5.40 25.60 23.80 6 12.40 40.25 43.07 8 20.40 50.65 57.10 10 28.50 56.75 60.37 12 35.20 59.95 14 42.10 60.45 16 47.40 18 52.10 20 57.10 22 61.00

[Graph 1]

[Graphic Water Evaporation Rate by Drying Method]

[Moisture Evaporation Rate by Drying Method] time Dry way Heavy water drying MW drying Thermoelectric Medium MW Drying 0 0.00 0.00 0.00 2 0.60 8.20 5.17 4 4.80 17.40 18.63 6 7.00 14.65 19.27 8 8.00 10.40 14.03 10 8.10 6.10 3.27 12 6.70 3.20 14 6.90 16 5.30 18 4.70 20 5.00 22 3.90

[Graph 2]

[Water Evaporation Rate Graph According to Drying Method]

[Energy Efficiency by Drying Method] Minutes Energy efficiency according to drying method (%) In-oil drying (A) Microwave Drying (B) Thermoelectric Oil + Microwave Drying (C) Energy consumption 540.44 kcal 220.84 kcal 157.74kcal cost 50.15 KRW KRW 15.4 11 won Energy efficiency compared to theoretical energy 6.87% 16.82% 23.55%

As shown in the above embodiment, the time for evaporating the entire moisture is about 22 minutes for drying in oil (A) using thermoelectric medium oil, about 14 minutes for using microwave drying (B) only, and for drying with thermoelectric oil and microwave drying. When (C) is used at the same time (C) is about 10 minutes, the fastest time to evaporate the total moisture is when using the thermoelectric fluid and microwave drying at the same time (C).

In the case of (A), in order for the thermal energy obtained from the direct fire to be transferred to the thermoelectric medium oil and the thermal energy is transferred back to the combined water in the core, the temperature of the thermoelectric medium oil must be higher than the boiling point of the water. Since the heat energy is consumed in the phase change, the temperature difference of the thermoelectric medium oil is enough to transfer heat to the core only after the second half of evaporation of the moisture. Since the effect occurs, it is thought that the amount of evaporation decreased toward the second half.

In case of (B), there is no heat transfer medium as in case of (A), but microwaves transmit radio energy evenly throughout the solid and generate wavelength (2,450MHz) which can absorb water molecules well. It is thought that the initial evaporation speed is higher than that of (A) because the internal energy of water on the surface is increased by the frictional heat of the water molecule itself due to the induction of rotation. However, the reason why the evaporation rate suddenly decreases in the latter part is that the number of internal bonds due to the presence of the cell membrane cannot be the surface water or the free water. It is considered that the decrease of the effect of the propagation energy due to the microwave is reduced.

On the other hand, in the case of (C), the free water on the surface is evaporated by the evenly transmitted radio energy at the beginning, and the bound water is easily removed by the osmotic pressure in the latter part, and the thermoelectric fluid can effectively transfer the heat energy to the surface water on the surface of the solid particles. The oil molecules in close proximity to the solid particles act as a mediator that can cause friction of water and destroy cell membranes. I think.

The results of Table 6 comparing the evaporation rate (g / min) show that even if the thermoelectric fluid is present, the heat transfer effect by the microwave, the heat transfer (density increase) effect by the thermoelectric medium oil, and the cell membrane destruction effect are explained. If the rate of evaporation in the middle is different, it can be confirmed from the improved results, and the more thermoelectric oil, the more effective the effect is expected.

In addition, the energy costs required to evaporate the total moisture are 78% cheaper than (A) and 28.6% cheaper than (B) for (C) as well as energy efficiency as shown in Table 7. In the case of using a thermoelectric medium and a microwave can be said to be a very advanced process technology compared to other processes.

2) Comparison of drying efficiency according to mixing ratio of thermoelectric oil

Since the final drying time in the microwave apparatus is expected to increase as more thermoelectric medium oils are obtained from the results of the above example, an optimal thermoelectric medium oil mixing ratio was determined according to energy efficiency. The experimental method prepared 100 g of paper sludge 60% of water discharged from the factory mainly producing woodfree paper and crushed into 100 mesh. Then, the paper sludge and thermoelectric medium oil were added to the microwave drying apparatus at a ratio of 1: 0.05, 0.2, 0.5, 1, 1.5 to obtain the following results.

[Moisture evaporation per hour according to drying method] Time (seconds) Moisture evaporation per hour 0g 5 g 20g 50 g 100 g 150 g 0 0.00 0.00 0.00 0.00 0.00 0.00 30 0.25 0.20 0.20 0.17 0.20 0.10 60 1.45 1.20 0.95 0.47 0.40 0.20 90 4.50 4.13 4.30 2.00 0.75 0.55 120 8.20 7.97 8.55 5.17 2.55 2.75 150 12.6 12.20 13.05 9.27 5.90 6.60 180 17.15 16.77 17.80 13.83 10.20 11.35 210 21.35 21.57 22.65 18.70 14.90 16.20 240 25.60 26.27 27.45 23.80 19.90 21.25 270 29.60 31.03 32.10 28.87 24.90 26.40 300 33.40 35.20 36.60 33.77 29.95 31.50 330 36.90 39.17 40.75 38.50 34.90 36.65 360 40.25 42.73 44.45 43.07 39.70 41.70 390 43.25 46.13 47.70 47.37 44.40 46.15 420 45.95 49.13 50.55 51.17 48.75 50.25 450 48.55 51.60 53.05 54.47 52.50 53.80 480 50.65 53.87 55.05 57.10 55.60 56.65 510 52.55 55.70 56.65 58.87 57.85 58.90 540 54.25 57.37 58.00 59.87 59.25 59.65 570 55.60 58.67 58.90 60.37 59.85 59.95 600 56.75 59.70 59.75 60.20 60.10 630 57.80 60.57 60.25 660 58.60 60.90 60.75 690 59.35 61.10 720 59.95 750 60.45

[Graph 3]

[Graphic Water Evaporation Rate by Drying Method]

[Moisture Evaporation Rate by Drying Method] Time (seconds) Evaporation Speed Per Hour 0g 5 g 20g 50 g 100 g 150 g 0 0.00 0.00 0.00 0.00 0.00 0.00 30 0.25 0.20 0.20 0.17 0.20 0.10 60 1.20 1.00 0.75 0.30 0.20 0.10 90 3.05 2.93 3.35 1.53 0.35 0.35 120 3.70 3.83 4.25 3.17 1.80 2.20 150 4.40 4.23 4.50 4.10 3.35 3.85 180 4.55 4.57 4.75 4.57 4.30 4.75 210 4.20 4.80 4.85 4.87 4.70 4.85 240 4.25 4.70 4.80 5.10 5.00 5.05 270 4.00 4.77 4.65 5.07 5.00 5.15 300 3.80 4.17 4.50 4.90 5.05 5.10 330 3.50 3.97 4.15 4.73 4.95 5.15 360 3.35 3.57 3.70 4.57 4.80 5.05 390 3.00 3.40 3.25 4.30 4.70 4.45 420 2.70 3.00 2.85 3.80 4.35 4.10 450 2.60 2.47 2.50 3.30 3.75 3.55 480 2.10 2.27 2.00 2.63 3.10 2.85 510 1.90 1.83 1.60 1.77 2.25 2.25 540 1.70 1.67 1.35 1.00 1.40 0.75 570 1.35 1.30 0.90 0.50 0.60 0.30 600 1.15 1.03 0.85 0.15 630 1.05 0.87 0.50 660 0.80 0.33 0.50 690 0.75 0.20 720 0.60 750 0.50

[Graph 4]

[Water Evaporation Rate Graph According to Drying Method]

Therefore, as shown in [Graph 3] and [Graph 4], the larger the capacity of the thermoelectric medium oil, the higher the amount of water evaporation per hour and the faster the rate of water evaporation. First of all, the evaporation time is up to 24% as the content of the thermoelectric medium oil increases, and the evaporation time is up to 24% (750 seconds when the thermoelectric medium oil is 0g, and about 570 seconds after the 50g of the paper sludge 100g). As shown in [Table 9], when the thermoelectric oil content is 50g or more (1: 0.5 or more), the water evaporation completion time converged almost uniformly. This is because it takes more time to raise the temperature because micro energy is consumed as much as the thermoelectric medium oil used to raise the temperature of the papermaking sludge including the thermoelectric medium oil until the microwaves evaporate moisture (that is, 100 ° C). Improvement period). However, it can be seen that the evaporation completion time after the temperature has risen to a certain level is almost proportional to the amount of the thermoelectric fluid input.

In addition, the maximum moisture evaporation rate, as shown in [Graph 4], shows that the maximum moisture evaporation rate for microwave drying of papermaking sludge in the absence of thermoelectric medium oil (0g) is 4.55g per 30 seconds, whereas the thermoelectric medium oil is 150g. The maximum water evaporation rate during microwave drying for paper sludge was 5.15g per 30 seconds and was almost proportional to the amount of thermoelectric oil input. This is an improvement of 11.66% of evaporation rate, and it is thought that at least this drying efficiency will be improved in the continuous process.

In particular, the trend of moisture evaporation in the graph shows that in the case of paper sludge containing 0g of thermoelectric medium oil, the evaporation rate is fast in the early stage, while the drying speed is slowing in the latter stage. This suggests that free water outside the sludge evaporates rapidly, but it is difficult to evaporate the bound water in the deep sludge. However, the water evaporation tendency of the papermaking sludge in which thermoelectric oil was introduced shows that the evaporation rate is slow compared to the dry mixture in which the thermoelectric medium is not added initially, while the evaporation rate is increased in the latter period, and thus shows an excellent effect of evaporating the internally bound water. . Therefore, it is clear that the drying efficiency improves in the case of not using thermoelectric oil as a whole, but as mentioned in [Graph 3] and [Graph 4] (marked as “improved interval” in the graph), thermoelectric If there is a way to increase the initial water evaporation rate while using the medium oil, the drying efficiency can be further improved.In the next test, the initial water evaporation rate when the thermoelectric medium oil is added, such as preheating the thermoelectric oil, In order to improve, the experiment was performed by changing the input method.

3) Comparison of Drying Efficiency by Paper Sludge and Thermoelectric Oil Input Method

In order to increase the initial water evaporation rate, the following experiments were carried out with different input methods when paper sludge and thermoelectric fluid were introduced into the microwave device. The experimental method was discharged from the factory mainly producing woodfree paper, and 100g of paper sludge pulverized with 100% moisture content was prepared, and 50g of thermoelectric medium oil was prepared under the conditions shown in Table 11. Drying was performed using a wave drying apparatus.

[Moisture Evaporation Per Hour According to Input Method] Time (seconds) Moisture evaporation 50 g in no action sludge Crushed sludge
50g thermoelectric oil preheated to 100 ℃ 50g without preheating crushed sludge 50g simultaneous grinding of sludge and thermoelectric oil 0 0.00 0.00 0.00 0.00 30 0.20 0.30 0.10 0.10 60 0.95 2.83 0.33 1.60 90 2.80 7.80 2.00 3.30 120 5.90 13.07 5.33 6.30 150 9.50 18.47 9.47 10.20 180 13.45 23.87 14.10 14.20 210 17.65 29.13 19.13 18.40 240 21.90 34.33 24.23 22.80 270 26.05 39.20 29.37 27.00 300 30.05 43.90 34.47 31.00 330 33.95 48.17 39.47 35.20 360 37.50 51.90 44.10 39.00 390 40.80 54.83 48.37 42.40 420 43.90 57.20 52.17 45.90 450 46.70 58.80 55.13 49.00 480 49.30 59.70 57.50 52.10 510 51.60 60.13 59.03 55.00 540 53.55 60.45 59.80 57.20 570 55.35 60.17 59.00 600 56.85 60.37 60.20 630 58.05 660 58.95 690 59.65 720 60.10 750 60.45

[Graph 5]

[Graphic evaporation amount per hour according to the input method]

[Moisture Evaporation Rate by Feeding Method] Time (seconds) Moisture acceleration With sludge
50g thermoelectric oil Milled sludge and preheated to 100 ℃
50g thermoelectric oil Without sludge and preheat
50g thermoelectric oil Sludge and Thermoelectric Oil 50g
Simultaneous grinding 0 0.00 0.00 0.00 0.00 30 0.20 0.30 0.10 0.10 60 0.75 2.53 0.23 1.50 90 1.85 4.97 1.67 1.70 120 3.10 5.27 3.33 3.00 150 3.60 5.40 4.13 3.90 180 3.95 5.40 4.63 4.00 210 4.20 5.27 5.03 4.20 240 4.25 5.20 5.10 4.40 270 4.15 4.87 5.13 4.20 300 4.00 4.70 5.10 4.00 330 3.90 4.27 5.00 4.20 360 3.55 3.73 4.63 3.80 390 3.30 2.93 4.27 3.40 420 3.10 2.37 3.80 3.50 450 2.80 1.60 2.97 3.10 480 2.60 0.90 2.37 3.10 510 2.30 0.43 1.53 2.90 540 1.95 0.32 0.77 2.20 570 1.80 0.37 1.80 600 1.50 0.20 1.20 630 1.20 660 0.90 690 0.70 720 0.45 750 0.35

[Graph 6]

[Water evaporation rate graph according to the feeding method]

When the paper sludge and the preheated thermoelectric oil were added without any action, as shown in the above experimental results. <When the paper sludge and the preheated thermoelectric fluid were mixed together and pulverized. In case of feeding into non-thermal thermoelectric oil, the drying efficiency was higher in the order of paper sludge but then into sludge preheated to 100 ℃. First of all, crushing and adding paper sludge was more efficient than adding it without any action. This is considered to be due to the effect of increasing the heat transfer efficiency between the particles by decreasing the volume per unit mass due to the smaller particle size by grinding. Secondly, the method of pulverizing paper sludge and then simply adding it to thermoelectric medium rather than mixing and pulverizing paper sludge together with thermoelectric medium oil showed a slight improvement in drying efficiency. It is considered that when the paper sludge and thermoelectric medium oil are mixed and pulverized at the same time, the thermoelectric medium oil prevents evaporation by blocking a fine evaporation path when the bound water in the paper sludge evaporates. Lastly, the paper sludge was crushed and then put into a preheated thermoelectric fluid and dried best. This creates an atmosphere in which the initial microwaves can be used to raise the moisture temperature in the paper sludge as expected in previous experiments, and immediately takes advantage of the expected effects of the thermoelectric fluid even after raising it above 100 ° C. The drying efficiency was improved. The effects of preheating were greater than any other measures, and it can be clearly seen from [Graphs 5 and 6] that the improvement intervals in [Graphs 3 and 4] were all improved by the preheating of thermoelectric fluids. Moreover, the drying speed per 30 seconds is 5.40g, which is the fastest speed in the experiment to date. It was found that the preheated thermoelectric fluid approached the initial evaporation rate and slowness point, which was pointed out earlier, but rather increased to the maximum evaporation rate. Therefore, preheating and supplying the thermoelectric medium oil can maximize the initial evaporation rate. Therefore, the final evaporation time can be shortened and the residence time in the microwave window can be shortened during the continuous process. I can do it. In order to examine the preheating effect of the thermoelectric fluid in more detail, the following experiment was examined in more detail.

In this experiment, the residual amount of thermoelectric medium oil in the dried paper sludge was also measured. As a result, as shown in [Table 12], when the paper sludge and thermoelectric oil were mixed and pulverized at the same time, the residual amount increased. This is considered to be because the thermoelectric fluid invades the sludge deeply as predicted above. If there is a large amount of residual thermoelectric oil in the dry matter may be a disadvantage if the thermoelectric fluid in the future to be separated for any reason.

[Residual Thermoelectric Oil in Paper Sludge after Drying] Determination of Thermoelectric Oil Content in Paper Sludge after Drying Contents No action sludge Crushed sludge
50 g thermoelectric oil, preheated to 100 ° C Grinded Sludge Preheated Thermoelectric Oil 50g Sludge and Thermoelectric Oil 50g
Simultaneous grinding Initial Sludge Mass (g) 100 100 100 100 Final steam evaporation (g) 61.1 61 61.1 61.1 Dry Sludge Mass (g) 68.6 65.43 65 101 Final oil mass (g) 29.7 26.43 26 62 Thermoelectric Oil Residue (%) 43.30% 40.39% 40.00% 61.39%

4) Comparison of drying efficiency according to preheating temperature of thermoelectric medium oil

The experimental method was prepared 100g of paper sludge pulverized with 100% moisture discharged from the factory mainly producing woodfree paper, and preheated the temperature of 50g thermoelectric medium oil to 100 ℃ and 150 ℃, respectively After drying was carried out using a microwave.

[Moisture evaporation per hour according to preheating temperature] time Moisture evaporation 0 ℃ 100 ℃ 150 ℃ 0 0.00 0.00 0.00 30 0.10 0.30 3.25 60 0.33 2.83 9.15 90 2.00 7.80 14.90 120 5.33 13.07 20.40 150 9.47 18.47 25.75 180 14.10 23.87 30.95 210 19.13 29.13 35.90 240 24.23 34.33 40.60 270 29.37 39.20 45.15 300 34.47 43.90 49.15 330 39.47 48.17 52.50 360 44.10 51.90 55.15 390 48.37 54.83 57.10 420 52.17 57.20 58.35 450 55.13 58.80 58.95 480 57.50 59.70 59.30 510 59.03 60.13 540 59.80 60.45 570 60.17 600 60.37

[Graph 7]

[Water evaporation amount per hour according to preheating temperature]

[Moisture evaporation rate according to preheating temperature] time Evaporation speed 0 ℃ 100 ℃ 150 ℃ 0 0.00 0.00 0.00 30 0.10 0.30 3.25 60 0.23 2.53 5.90 90 1.67 4.97 5.75 120 3.33 5.27 5.50 150 4.13 5.40 5.35 180 4.63 5.40 5.20 210 5.03 5.27 4.95 240 5.10 5.20 4.70 270 5.13 4.87 4.55 300 5.10 4.70 4.00 330 5.00 4.27 3.35 360 4.63 3.73 2.65 390 4.27 2.93 1.95 420 3.80 2.37 1.25 450 2.97 1.60 0.60 480 2.37 0.90 0.35 510 1.53 0.43 540 0.77 0.32 570 0.37 600 0.20

[Graph 8]

[Water evaporation rate graph according to preheating temperature]

As shown in the above experimental data, the higher the preheating temperature, the faster the initial evaporation rate and the higher the maximum evaporation rate.

5) Comparison of energy efficiency according to supply thickness of paper sludge and thermoelectric medium oil

Experimental method was prepared 150g of paper sludge pulverized to 100 mesh moisture content discharged from the factory mainly producing woodfree paper (Woodfree paper), and drying was performed using a microwave drying apparatus.

[Moisture evaporation per hour according to the thickness of the input paper sludge] Time (seconds) Evaporation 1cm 2cm 3cm 4cm 0 0.00 0.00 0.00 0.00 30 0.40 0.25 0.20 0.10 60 1.40 1.00 0.75 0.35 90 4.75 4.25 2.10 1.70 120 10.20 9.90 7.20 6.80 150 16.20 14.50 12.85 12.15 180 20.95 20.65 18.70 17.20 210 26.35 26.60 25.00 22.10 240 32.40 33.15 29.85 28.25 270 37.85 38.30 35.55 33.15 300 42.50 43.00 40.60 38.70 330 46.95 47.50 45.55 44.25 360 51.45 52.55 50.20 49.65 390 56.65 56.65 54.75 54.90 420 61.45 61.15 57.90 59.70 450 65.95 64.55 62.85 63.85 480 69.85 68.00 66.55 68.00 510 74.10 72.20 71.00 71.70 540 77.15 75.55 74.40 73.80 570 80.05 78.50 77.65 78.50 600 82.75 81.70 80.25 81.25 630 85.20 84.50 82.85 83.30 660 87.50 86.65 84.80 84.70 690 89.05 88.20 86.80 86.60 720 89.45 88.30 88.10 750 90.45 89.00 89.10 780 90.20 90.00 810 90.40

[Graph 9]

[Graphics of moisture evaporation per hour according to the thickness of input paper sludge]

[Moisture evaporation rate according to the thickness of the input paper sludge] Time (seconds) Evaporation speed 1cm 2cm 3cm 4cm 0 0.00 0.00 0.00 0.00 30 0.40 0.25 0.20 0.10 60 1.00 0.75 0.55 0.25 90 3.35 3.25 1.35 1.35 120 5.45 5.65 5.10 5.10 150 6.00 4.60 5.65 5.35 180 4.75 6.15 5.85 5.05 210 5.40 5.95 6.30 4.90 240 6.05 6.55 4.85 6.15 270 5.45 5.15 5.70 4.90 300 4.65 4.70 5.05 5.55 330 4.45 4.50 4.95 5.55 360 4.50 5.05 4.65 5.40 390 5.20 4.10 4.55 5.25 420 4.80 4.50 3.15 4.80 450 4.50 3.40 4.95 4.15 480 3.90 3.45 3.70 4.15 510 4.25 4.20 4.45 3.70 540 3.05 3.35 3.40 2.10 570 2.90 2.95 3.25 4.70 600 2.70 3.20 2.60 2.75 630 2.45 2.80 2.60 2.05 660 2.30 2.15 1.95 1.40 690 1.55 1.55 2.00 1.90 720 1.25 1.50 1.50 750 1.00 0.70 1.00 780 1.20 0.90 810 0.40

[Graph 10]

[Water evaporation rate graph according to the thickness of the input paper sludge]

As a result of this experiment, there was no big difference, but 2cm thickness was found to be the most appropriate. If the thickness is too thin, the energy efficiency is relatively low because the density between particles is small and friction between water molecules is small. As the thickness increases, the density between particles increases, while the microwave reaching the core decreases, thereby reducing energy efficiency. Therefore, it is judged that it is desirable to determine through experiment on the appropriate thickness of each device.

6) Odor and Dust

In the case of using thermoelectric medium oil, since it is dried through the thermoelectric medium oil, there is no dust which is always a problem during drying. In addition, as described above, all of the odors inherent in the biomass are burned off in the flame furnace 70, so that most of them can be removed.

7) Review of experimental results

Based on all the test results described above, in order to determine how much the drying efficiency of the present technology is improved compared to the conventional technology, the experimental results are summarized as the following data.

[Moisture Evaporation Per Hour According to Drying Method] time Dry way In-oil drying (A) MW drying (B) 150 ℃ Thermoelectric oil MW drying (C) 0 0.00 0.00 0.00 2 0.60 8.20 20.40 4 5.40 25.60 40.60 6 12.40 40.25 55.15 8 20.40 50.65 59.30 10 28.50 56.75 12 35.20 59.95 14 42.10 60.45 16 47.40 18 52.10 20 57.10 22 61.00

[Graph 11]

[Hydration Evaporation Graph per Hour by Drying Method_Comparison of Experimental Results]

[Moisture Evaporation Rate by Drying Method_Comparison of Experimental Results] time Dry way In-oil drying (A) MW drying (B) 150 degree thermoelectric oil MW drying (C) 0 0.00 0.00 0.00 2 0.60 8.20 20.40 4 4.80 17.40 20.20 6 7.00 14.65 14.55 8 8.00 10.40 4.15 10 8.10 6.10 12 6.70 3.20 14 6.90 16 5.30 18 4.70 20 5.00 22 3.90

[Graph 12]

[Moisture Evaporation Rate Graph According to Drying Method]

[Energy Efficiency According to Drying Method_Comparison of Experimental Results] Minutes Energy efficiency according to drying method (%) In-oil drying (A) Microwave Drying (B) 150 degree preheated thermoelectric oil + microwave drying (C) Energy consumption 540.44 kcal 220.84 kcal 126.2kcal (excluding 150 degree preheat energy)
135.6 Kcal (including 150 degree preheat energy) Cost / 100g 50.15 KRW KRW 15.4 8.8won
9.46won Energy efficiency versus theoretical energy 6.87% 16.82% 31.70%
29.50%

As shown in Table 19 and 20, the drying completion rate was about 2.75 times faster than in the case of (C), which was the last developed condition, and about 1.75 times faster than in the case of (B). In the case of (C), the maximum water evaporation amount also increased about 2.51 times compared to that of (A) and about 1.17 times compared to that of (B). The cost of energy is also about 82.5% cheaper than (A) and 42.9% cheaper than (B) for preheating (C). In particular, even if a general deoiling process is included later in the process of (C), it is expected to save about 81% of the operation cost compared to the process of (A) and about 37% of the process of (B). I think it will be higher. Therefore, the use of preheated thermoelectric medium oil and microwave (C) in terms of energy efficiency can be said to be a much improved process technology compared to other processes (B, C).

Therefore, in summary the present invention,

Storing the thermoelectric fluid in the thermoelectric fluid storage tank 30;

Mixing 100 parts by weight of biomass and 5 to 200 parts by weight of the heated thermoelectric medium in a mixer 20, and then pulverizing the mixture into 30 to 150 mesh in a grinder 10;

Injecting the mixture into the microwave drying apparatus 40 and heating it to 80 to 300 ° C. until the moisture content is 30% or less;

The drying step of the mixture is transferred to the thermoelectric medium oil separator (50) to separate or remove the thermoelectric medium oil component.

In addition, the present invention

Storing the thermoelectric fluid in the thermoelectric fluid storage tank 30;

Crushing the biomass into the grinder 10 into 30 to 150 meshes;

Injecting 100 parts by weight of the pulverized biomass and 5 to 200 parts by weight of thermoelectric fluid stored in the thermoelectric fluid storage tank 30 to the microwave drying apparatus 40;

Heating the input put into the microwave drying apparatus 40 to 80 to 300 ° C. and drying the water until the moisture content is 30% or less;

10: grinder 20: mixer
30: thermoelectric medium storage tank 31: heater
32: thermoelectric fluid transfer pipe 33: thermoelectric fluid inlet
40: microwave drying device 41: hopper
42: microwave generating device 43: bubble inhibitor storage tank
44: bubble inhibitor nebulizer 45: water vapor collector
46: steam discharge port 47: steam transfer pipe
48: conveyor belt 49: biomass outlet
50: thermoelectric fluid separator 51: thermoelectric fluid transfer pipe
60: condenser 70: direct flame
80: oil / water separator

Claims

Storing the thermoelectric fluid in the thermoelectric fluid storage tank 30;
Heating to 50 to 250 ° C. before mixing the thermoelectric medium oil;
Mixing 100 parts by weight of biomass and 5 to 200 parts by weight of the heated thermoelectric medium in a mixer 20, and then pulverizing the mixture into 30 to 150 mesh in a grinder 10;
Injecting the mixture into the microwave drying apparatus 40 and heating it to 80 to 300 ° C. until the moisture content is 30% or less;
Transferring the mixture passed through the drying step to a thermoelectric medium oil separator (50) to separate or remove the thermoelectric oil component; Drying method of biomass, characterized in that consisting of

Storing the thermoelectric fluid in the thermoelectric fluid storage tank 30;
Heating to 50 to 250 ° C. before mixing the thermoelectric medium oil;
Crushing the biomass into the grinder 10 into 30 to 150 meshes;
Injecting 100 parts by weight of the pulverized biomass and 5 to 200 parts by weight of thermoelectric fluid stored in the thermoelectric fluid storage tank 30 to the microwave drying apparatus 40; Heating the input put into the microwave drying apparatus 40 to 80 to 300 ° C. and drying the water until the moisture content is 30% or less;
Transferring the mixture passed through the drying step to a thermoelectric medium oil separator (50) to separate or remove the thermoelectric oil component; Drying method of biomass, characterized in that consisting of

delete

The method according to claim 1 or 2,
Drying method of the biomass, characterized in that the mixture is 1.5 ~ 3.5cm thick

The method according to claim 1 or 2,
Spraying a bubble inhibitor to the mixture to suppress bubble generation in the heating step; and further comprising drying the biomass.

The method according to claim 1 or 2,
Method of imparting ultrasonic vibration in the microwave device 20 by using an ultrasonic generator in order to increase the bubble suppression efficiency in the heating step; drying method of the biomass, characterized in that

The method according to claim 1 or 2,
Drying method of the biomass, characterized in that a method using a vacuum or hot air of 70 ~ 200 ℃ in parallel to the heating step

The method according to claim 1 or 2,
The thermoelectric medium oil is a drying method of biomass, characterized in that one or a mixture of two or more selected from the group consisting of mineral oil, vegetable oil, animal oil and their waste oil.

The method of claim 5, wherein
The bubble inhibitor
Alcohol, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, mineral oil ( one or more selected from the group consisting of mineral oil, oxystearine, dimethyl polysiloxane, silicon dioxide, sorbitan monostearate, silicon resin, etc. Drying method of biomass, characterized in that the mixture

The method according to claim 1 or 2,
Biomass drying method, characterized in that the biomass dried by the drying method using the solvent itself or the extraction-distillation or compression or centrifugal separator through the deoiling process to separate and reuse the thermoelectric medium oil.

The method of claim 10,
When the thermoelectric medium oil is separated from the dried biomass, the drying method of the biomass is characterized in that the dried biomass has a predetermined calorific value by controlling the residual amount of the thermoelectric medium oil.