KR20240069318A - Apparatus for removing oil using three phase centrifugal separator - Google Patents

Abstract

The present invention relates to an oil removal device using a three-phase centrifuge, which removes oil from food waste using a three-phase centrifuge. It includes a pre-processing unit that preprocesses food waste, and a three-phase centrifuge to separate the oil from food waste. An oil removal unit that removes oil, an anaerobic digestion unit that anaerobically digests food waste, a biogas purification unit that purifies the discharged biogas, a residue treatment unit that processes the discharged waste, and a wastewater treatment unit that processes the discharged wastewater. It is characterized by including a wastewater treatment unit. Therefore, the present invention improves the oil removal rate contained in food waste in order to minimize trouble in the anaerobic digestion process and ensure stable operation by improving the screw blade shape of the existing three-phase centrifuge and applying an oil-water separation diaphragm to increase the oil removal rate by more than 80%. Provides an effect that can be increased.

Description

Oil removal device using a three-phase centrifugal separator {APPARATUS FOR REMOVING OIL USING THREE PHASE CENTRIFUGAL SEPARATOR}

The present invention relates to an oil removal device using a three-phase centrifuge, and more specifically, to an oil removal device using a three-phase centrifuge to increase the removal efficiency of oil contained in food waste or food wastewater. It's about.

In general, as industry develops and lifestyles become more prosperous, a large amount of food waste is being generated. These food wastes contain a large amount of moisture and salt, so they are easily decomposed, and recovering them as high-quality resources during the recycling process is costly and difficult, and this generates strong odors and food wastewater. There is a problem that is not easy to do.

Various treatment means are being developed to treat food waste at the source, and among them, a food grinder processor that is installed under the kitchen sink of each household and grinds and disposes of food waste has been proposed.

This food grinder is a technology that is installed under the sink in the kitchen and operates to finely crush the food waste after putting food waste in it and then discharges it to the outside through a transfer pipe.

The food grinder is installed at the bottom of the sink's drain, uses grinding blades rotated by an electric motor to grind food waste, and then discharges it to the outside through a transfer pipe. It conveniently disposes of food waste, providing user convenience. The purpose is to provide convenience.

In general, the recycling of food waste, which is an organic waste, can be broadly divided into feed, composting, and anaerobic digestion methods. In Korea, about 90% of food waste is processed into compost and feed, and anaerobic digestion is about 10%. B. The proportion of anaerobic digestion is increasing due to the expansion of the anaerobic digestion (biogasification) business as the core of the government policy of “Complete the circular economy through recycling” and the active promotion of the “Bio Water Energy Expansion Roadmap” policy. ('21 110 biogasification facilities as of the end of the year → Expand to 140 in 2026)

Anaerobic digestion technology is also called “methane fermentation,” and its main purpose is to properly treat organic waste and simultaneously recover energy called methane. Anaerobic digestion technology is included in the category of biological treatment as it decomposes decomposable organic substances in anoxic conditions and converts them into methane. Initially, facultative anaerobic bacteria act to produce acetic acid and hydrogen through hydrolysis and acid fermentation. , At the point when oxygen is depleted, methanogenic bacteria, which are oblique anaerobic bacteria, produce methane using hydrogen and acetic acid.

One of the factors that interferes with normal operation during this anaerobic digestion process is oil (normal hexane extract), and food waste usually contains 1.5 to 4% of oil.

When such oil is introduced into the anaerobic digestion tank without being removed during the pretreatment process, the oil reacts with the alkaline source in the digester, causing a hardening phenomenon in the scum layer at the top of the digester through a saponification reaction, thereby suppressing the discharge of biogas. It causes pressure rise and overflow in the digester.

The principle of scum creation is the same reaction as the process of producing recycled soap by adding caustic soda to waste cooking oil.

RCOOR' + NaOH → RCOONa + R'OH

In addition, in the case of food waste transport pipes, as the outdoor temperature decreases in winter, the liquefied oil is separated and solidifies, attaching to the pipe in the form of scale, and gradually growing, causing a closed hole.

In this way, the oil contained in food waste is a substance that affects the normal operation of the anaerobic digestion tank and is restricted from entering the digester, so removing it as much as possible is the key. Most facilities operating in Korea operate without installing oil removal facilities.

In addition, according to data from the Ministry of Environment, the facility operation rate of food waste biogasification facilities is only around 70%. There may be various reasons for this, but in particular, the occurrence of scum at the top of the digester due to oil and the occurrence of pipe clogging are very significant. It is judged that it occupies.

In addition, the results of the demonstration and operation of a short-term nitrogen process pilot plant for the economical treatment of high-concentration nitrogen-containing wastewater, which is a conventional study (Jaemyung Lee of Cade Technology Research Institute, Organic Resources Society, March 2020), show that food composting at resource circulation facilities in Group G As a result of a three-phase centrifugal separator (facility capacity of 5 m ³ /hr) to remove solids and oil from food waste water dehydrated in the process, it was found that the oil (normal hexane extract material) removal rate was only about 48%.

In addition, the conventional “Oil collection and purification system for food waste wastewater using a three-phase centrifuge” refers to an oil collection and purification system for food waste wastewater using a three-phase centrifuge, which separates food waste into solid and liquid phases through a solid-liquid separator. This is a technology in which the solid phase is recycled as compost or feed, the liquid wastewater is separated into water and oil through a centrifuge, and the oil is used as biofuel after purification. There is no mention of the oil removal rate and the three-phase separation is performed in one stage. It consists of a two-stage solid-liquid separator and two-stage oil separation from the liquid phase.

Therefore, the oil removal efficiency of the existing three-phase centrifuge is only around 40%, so improving the oil removal efficiency is essential for stable anaerobic digestion operation when carrying out biogasification projects for food waste.

The oil separated in a conventional three-phase separator is condensed using a reduced pressure evaporator to produce an evaporated liquid, and the remaining substances are filtered through an oil filter. The filtrated substances generated here are mixed with the previously generated evaporated liquid and returned to the reduced pressure evaporator. A technology is disclosed to improve the quality of oil and increase the recovery rate, which is the collection efficiency of oil, by resupplying it to .

However, the prior art also has a problem in that only the upper oil separated in the three-phase separator is circulated, and the separation rate of the three-phase separator is low, resulting in a low oil recovery rate. In other words, there was a problem that the oil remaining in the food waste water layer of the three-phase separator could not be recovered, and a recovery rate higher than the oil separation efficiency of the three-phase separator could not be secured.

Republic of Korea Patent Publication No. 10-2019-0077170 (July 3, 2019) Republic of Korea Patent No. 10-2005816 (August 1, 2019) Republic of Korea Patent No. 10-2413751 (June 28, 2022)

The present invention was developed to solve the conventional problems described above. In order to minimize problems in the anaerobic digestion process and improve the oil removal rate contained in food waste for stable operation, the screw blade shape of the existing three-phase centrifuge was improved and The purpose is to provide an oil removal device using a three-phase centrifuge that can increase the oil removal rate by more than 80% through the application of an oil-water separation diaphragm.

In addition, the present invention removes more than 97% of foreign substances through pretreatment such as crushing and sorting of brought in food waste, uniformizes the particle size to 3 mm or less, and decomposes organic substances through a separate two-phase digester configuration. Another purpose is to provide an oil removal device using a three-phase centrifuge that can be used.

In addition, the present invention is an anaerobic digestion tank (methane fermentation tank) in which organic matter flows into the digester in the range of 2.5kgVS/m ³ ·d and decomposes, and ORP (oxidation reduction potential), which can be analyzed in real time for monitoring of the anaerobic digestion tank, Another purpose is to provide an oil removal device using a three-phase centrifuge that is equipped with a pH meter, thermometer, pressure gauge, etc. and can stably and automatically control the amount of substrate input through PLC linked control.

In addition, the present invention maximizes the usability of biogas by removing foreign substances such as moisture, hydrogen sulfide, and siloxane in the biogas produced during the anaerobic digestion process and separating CO ₂ and H ₂ from the purified biogas. The digested filtrate is separated into solids and liquids through a centrifugal dehydrator, and the separated solid phase (dehydrated cake) is dried in a sludge drying facility. The dried product is connected to a coal-fired power plant, and the liquid desorbed filtrate separated from the residue treatment unit is treated through a wastewater treatment process. Another purpose is to provide an oil removal device using a three-phase centrifugal separator that can optimally utilize by-products connected to a sewage treatment plant.

In addition, the present invention is a food waste anaerobic digestion technology by removing oil contained in food waste by improving the screw blade shape of the existing three-phase centrifuge and applying an oil-water separation diaphragm to remove more than 80% of oil, thereby reducing the scum at the top of the digester caused by oil. As the pressure rise and overflow phenomenon in the digester due to occurrence and the occurrence of piping blockage due to hardening of oil in winter can be prevented in advance, the anaerobic digester can be operated without trouble, thus increasing the facility operation rate due to stable facility operation. Another purpose is to provide an oil removal device using a three-phase centrifuge that can increase the facility operation rate by more than 10% and the amount of biogas generated by more than 15% compared to existing technology as the organic matter removal rate increases.

In addition, the present invention introduces pre-treated food waste into the digester under OLR 2.5kgVS/m ³ ·d conditions, where organic substances are decomposed, and an ORP, pH meter, thermometer, pressure gauge, etc. capable of real-time analysis are used to monitor the anaerobic digestion tank. Another purpose is to provide an oil removal device using a three-phase centrifuge that can be used as a facility operation manual by providing unmanned automatic operation of the facility to the operator of the anaerobic digestion facility through the installed anaerobic digestion system and automatic control. Do it as

The present invention for achieving the above object is an oil removal device that removes oil from food waste using a three-phase centrifuge, comprising: a pre-processing unit for pre-processing food waste; An oil removal unit 200 installed downstream of the pretreatment unit to separate and remove oil from food waste using a three-phase centrifuge; An anaerobic digestion unit (400) installed downstream of the oil removal unit (200) to anaerobically digest food waste; A biogas purification unit 500 installed on one side downstream of the anaerobic digestion unit 400 to purify the biogas discharged from the anaerobic digestion unit 400; A waste treatment unit 600 installed downstream of the anaerobic digestion unit 400 to process waste discharged from the anaerobic digestion unit 400; and a wastewater treatment unit 700 installed downstream of the waste treatment unit 600 to treat wastewater discharged from the waste treatment unit 600.

The preprocessing unit of the present invention includes a first preprocessing unit 100 that primarily preprocesses brought in food waste; and a second pretreatment unit 300 installed downstream of the oil removal unit 200 to secondarily preprocess food waste.

The first preprocessing unit 100 of the present invention includes a food input hopper that stores the brought in food waste, has a double screw installed at the bottom for transporting the food waste, and has perforated nets of a predetermined particle size installed at predetermined intervals; A crusher sorter installed downstream of the food input hopper to separate coarse foreign substances from the stored food waste through crushing and primary crushing; A secondary shredder installed downstream of the shredder and sorter to maintain the particle size below a predetermined level and select foreign substances through secondary shredding of the primary shredded and sorted food waste; And a screw press installed downstream of the secondary shredder to produce inflowable food waste water by separating the shredded and sorted food waste into dehydrated food cake and food waste water through dehydration.

The second preprocessing unit 300 of the present invention dehydrates the food cake separated by the screw press of the first preprocessing unit 100 and the desorbed liquid in the desorbed liquid tank of the three-phase centrifuge of the oil removal unit 200. A food cake mixer that mixes food evenly before adding it to the food TS control tank; A food TS control tank installed downstream of the food cake mixer and adjusting TS (Total Solid) to 10% through time constant hydration; A fine shredder installed downstream of the food TS control tank to crush the food waste shredded to a particle size of 10 mm or less in the first pre-processing unit 100 to a particle size of 3 mm or less; A fine sorter installed downstream of the fine shredder to select and remove vinyl and fibrous foreign substances larger than 3 mm from food particles crushed to 3 mm or less and maintain a foreign material removal rate of 96% or more; A cyclone installed downstream of the fine separator to remove fine inorganic substances (FS, Fixed Solid) such as sediment, crushed eggshells, and crushed shellfish to maintain a removal rate of foreign substances in the substrate at more than 97%; An intermediate storage tank installed downstream of the cyclone, where more than 97% of foreign substances contained in the food waste are removed and the particle size is uniformly pretreated to 3 mm or less, and then temporarily stored before being introduced into the anaerobic digestion unit 400. It is characterized by:

The oil removal unit 200 of the present invention includes a low-speed solid-liquid separator that separates coarse foreign substances of 4 mm or more contained in the food waste water from the food waste water separated in the pre-treatment unit; A three-phase centrifuge installed downstream of the low-speed solid-liquid separator to remove more than 80% of the oil by centrifuging the three phases of solid, liquid, and oil using centrifugal force; A three-phase centrifugal separator tank installed on one side downstream of the three-phase centrifugal separator to store solid matter and liquid desorbed liquid separated from the three-phase centrifuge and maintain a uniform concentration through a vertical shaft stirrer; An oil tank installed on the other side downstream of the three-phase centrifugal separator to temporarily store the oil separated from the three-phase centrifugal separator; An oil purification tank installed downstream of the oil tank to remove foreign substances such as moisture in the recovered oil by heating the recovered oil with a heating coil built into the oil tank; and an oil storage tank with a built-in heating coil installed downstream of the oil purification tank to temporarily store the oil produced in the oil purification tank.

The three-phase centrifuge of the present invention is characterized by having screw blades and oil-water separation plates at non-equal intervals.

The anaerobic digestion unit 400 of the present invention is characterized in that it consists of a two-phase anaerobic digestion system in which the acid fermentation tank and the anaerobic digestion tank are separated.

The biogas purification unit 500 of the present invention includes a primary desulfurization facility that first removes high concentration hydrogen sulfide contained in biogas by injecting FeCl ₃ into the anaerobic digestion tank of the anaerobic digestion unit 400; A water separator that first removes moisture in biogas by swirling flow method; A biogas dehumidifier installed downstream of the water separator to secondarily remove moisture by cooling the primarily removed moisture; A gas filter installed downstream of the biogas dehumidifier to thirdly remove fine dust and mist-like moisture in the biogas using a filter; A dry desulfurization facility installed downstream of the gas filter to secondarily remove hydrogen sulfide in the biogas first removed in the anaerobic digestion tank; A siloxane removal facility installed downstream of the dry desulfurization facility to remove siloxane in biogas using the adsorption function of activated carbon; A gas storage tank installed downstream of the siloxane removal facility to temporarily store biogas from which moisture, hydrogen sulfide, and siloxane have been removed; It is installed downstream of the gas storage tank and uses a membrane to separate CO ₂ from the biogas temporarily stored in the gas storage tank due to the difference in permeation rates between CH ₄ and CO ₂ membranes to produce CH ₄ of 98% or more. Membrane equipment producing biomethane; And a steam reforming facility installed at the rear of the membrane facility to produce more than 99% of H ₂ through a steam reforming reaction from biomethane from which CO ₂ has been separated and removed.

The waste disposal unit 600 of the present invention includes a digestion filtrate storage tank that temporarily stores the digestion filtrate generated in the anaerobic digestion unit 400; A centrifugal dehydrator installed downstream of the digestion filtrate storage tank to separate solid and liquid from the stored digestion filtrate; A dehydrated cake storage tank for temporarily storing the solid dehydrated cake separated from the centrifugal dehydrator; A sludge drying facility for producing a dehydrated cake with a moisture content of 80% temporarily stored in the dehydration cake storage tank into a dried product with a moisture content of 10% or less using a heat source of biogas.

The wastewater treatment unit 700 of the present invention includes a desorption liquid storage tank that stores the liquid separated from the centrifugal dehydrator of the waste treatment unit 600; A rapid mixing tank installed via a transfer pump downstream of the desorption liquid storage tank and reacting fine sludge with chemicals by adding polymer (PAC) and NaOH; a slow mixing tank that forms sludge floc through slow agitation using chemicals introduced in the rapid mixing tank; A pressurized flotation tank that floats the floc formed in the slow mixing tank by injecting fine air (30-100 μm) and removes suspended substances by a flotation sludge removal facility at the top; A pre-treatment treatment tank installed at the rear of the pressurized flotation tank to first remove organic substances and suspended solids in the wastewater and then adjust and equalize the flow rate before inputting it into the subsequent nitrogen and phosphorus removal process; A denitrifying tank installed at the rear end of the pre-treatment tank to remove nitrogen by transporting it by a transfer pump, supply an external carbon source, and install a submersible mixer to increase nitrogen removal efficiency through stirring; an aeration tank installed downstream of the denitrification tank to change ammonia nitrogen into nitrate nitrogen via nitrite nitrogen; MBR (Membrane Bio Reactor) installed downstream of the aeration tank to further remove organic matter, suspended solids, T-N (total nitrogen), and T-P (total phosphorus) contained in the wastewater; A linked treatment tank installed downstream of the MBR to link and treat treated water treated to a final T-N (total nitrogen) of 250 mg/L or less and T-P (total phosphorus) of 30 mg/L or less to a sewage treatment plant; and a wastewater sludge storage tank installed downstream of the pressure flotation tank to treat flotation sludge generated in the pressure flotation tank.

As discussed above, the present invention improves the oil removal rate contained in food waste by improving the screw blade shape of the existing three-phase centrifuge and applying an oil-water separation diaphragm to minimize trouble in the anaerobic digestion process and improve the oil removal rate contained in food waste for stable operation. Provides an effect that can increase by more than 80%.

In addition, through pre-processing of brought in food waste such as crushing and sorting, more than 97% of foreign substances are removed and the particle size is uniformized to 3 mm or less, and organic substances can be decomposed through a separate two-phase digester configuration. Provides effect.

In addition, organic matter flows into the digester in the range of 2.5kgVS/m ³ ·d of organic matter in the anaerobic digestion tank (methane fermentation tank) and is decomposed. ORP (oxidation reduction potential), pH meter, Thermometers, pressure gauges, etc. are installed to provide the effect of stably and automatically controlling the amount of substrate input through PLC linked control.

In addition, foreign substances such as moisture, hydrogen sulfide, and siloxane in the biogas produced during the anaerobic digestion process are removed, CO ₂ and H ₂ are separated from the purified biogas to maximize biogas utilization, and the digested filtrate that has passed through the anaerobic digestion tank is Solid-liquid separation is performed through a centrifugal dehydrator, and the separated solid phase (dehydrated cake) is dried in a sludge drying facility. The dried product is connected to a coal-fired power plant, and the liquid phase filtrate separated in the residue treatment unit is processed through a wastewater treatment process and then sent to a sewage treatment plant. It provides the effect of optimally utilizing linked by-products.

In addition, the anaerobic digestion technology for food waste by removing the oil contained in the food waste improves the screw blade shape of the existing three-phase centrifuge and applies an oil-water separation diaphragm to remove more than 80% of the oil, eliminating the risk of scum at the top of the digester caused by oil. As pressure rise and overflow within the digester and blockage of pipes due to hardening of oil in winter can be prevented in advance, the anaerobic digester can be operated without trouble, improving facility operation rate through stable operation of the facility and reducing organic matter. As the removal rate increases, it provides the effect of increasing facility operation rate by more than 10% and biogas generation by more than 15% compared to existing technology.

In addition, pre-processed food waste is introduced into the digester under the OLR of 2.5kgVS/m ³ ·d, where organic substances are decomposed. Anaerobic digestion is equipped with ORP, pH meter, thermometer, and pressure gauge that enable real-time analysis for monitoring the anaerobic digestion tank. The system and automatic control enable unmanned automatic operation of the facility, providing the operator of the anaerobic digestion facility with the effect of being able to use it as a facility operation manual.

Figure 1 is a detailed block diagram showing an oil removal device using a three-phase centrifuge according to an embodiment of the present invention.
Figure 2 is a schematic block diagram showing an oil removal device using a three-phase centrifuge according to an embodiment of the present invention.
Figure 3 is a detailed block diagram showing a wastewater treatment unit of an oil removal device using a three-phase centrifuge according to an embodiment of the present invention.
Figure 4 is a configuration diagram showing a three-phase centrifuge of an oil removal device using a three-phase centrifuge according to an embodiment of the present invention.
Figure 5 is a configuration diagram showing an oil-water separation diaphragm of a three-phase centrifuge of an oil removal device using a three-phase centrifuge according to an embodiment of the present invention.
Figure 6 is a configuration diagram showing the non-equally spaced screw blades of a three-phase centrifuge of an oil removal device using a three-phase centrifuge according to an embodiment of the present invention.

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

Figure 1 is a detailed block diagram showing an oil removal device using a three-phase centrifuge according to an embodiment of the present invention, and Figure 2 is a schematic diagram showing an oil removal device using a three-phase centrifuge according to an embodiment of the present invention. It is a block diagram, and Figure 3 is a detailed block diagram showing the wastewater treatment unit of the oil removal device using a three-phase centrifuge according to an embodiment of the present invention, and Figure 4 is a three-phase centrifuge according to an embodiment of the present invention. It is a configuration diagram showing the three-phase centrifuge of the oil removal device used, and Figure 5 is a configuration diagram showing the oil-water separation diaphragm of the three-phase centrifuge of the oil removal device using the three-phase centrifuge according to an embodiment of the present invention. Figure 6 is a configuration diagram showing the non-equally spaced screw blades of a three-phase centrifuge of an oil removal device using a three-phase centrifuge according to an embodiment of the present invention.

As shown in Figures 1 to 3, the oil removal device using a three-phase centrifuge according to this embodiment includes a pretreatment unit, an oil removal unit (200), an anaerobic digestion unit (400), and a biogas purification unit (500). , It is an oil removal device using a three-phase centrifuge to increase the removal efficiency of oil contained in food waste or food wastewater, including a waste treatment unit 600 and a wastewater treatment unit 700.

The pretreatment unit is a pretreatment means for preprocessing food waste, and includes a first pretreatment unit 100 that primarily preprocesses the brought in food waste, and a second pretreatment unit installed downstream of the oil removal unit 200 to secondarily preprocess the food waste. Of course, it is also possible to include a preprocessing unit 300.

The first pretreatment unit 100 is a preprocessing means that primarily preprocesses the brought in food waste. After first pretreating the food waste to 95% or more of foreign substances and particle size of 10 mm or less through crushing and sorting, the food waste is dehydrated. It is separated into dehydrated cake and food waste water to produce food waste water that can be introduced into a three-phase centrifuge.

This first pre-processing unit 100 removes more than 95% of foreign substances from the food waste brought into the first pre-processing unit 100 through primary and secondary crushing and sorting (crushing sorter and secondary crusher), and reduces particle size. It includes a solid-liquid separation process for oil separation after primary pretreatment to 10 mm or less, and consists of a food input hopper (101), a crusher (102), a secondary crusher (103), and a screw press (104).

The food input hopper 101 is a hopper member that stores the brought in food waste, has a double screw installed at the bottom to transport the food waste, and has perforated nets of a predetermined particle size installed at predetermined intervals.

This food input hopper 101 is shaped like a W (W), and a double screw is installed at the bottom for smooth food transfer, and perforated nets with a particle diameter of ø8mm are installed at 20mm intervals for smooth drainage of food waste water.

In addition, the food input hopper 101 is designed to have a storage capacity of more than 3 days of the designed loading amount in consideration of the standard deviation of the daily and seasonal loading amount (2 100 tons/day, 4 200 tons/day, 250 tons). /day 4, 300 tons/day 6, 350 tons/day 6) Input hoppers are installed, and since food waste contains low pH and a large amount of salt, the inside of the storage hopper is corrosion-resistant STS 304 or higher, thick. By setting it to 6.0mm or more, it can prevent sagging or bending due to bringing in food, and durability is ensured by using corrosion-resistant materials. Considering the high TS concentration, it is shaped like a “W” to avoid problems during storage and transportation. A double screw-type transfer conveyor is installed at the bottom, and the double screw is manufactured in a structure that can operate in both forward and reverse directions, so even if temporary blockage due to foreign substances occurs, it can be immediately resolved.

In addition, when food waste is brought in frozen during the winter, hot water piping is installed to prevent blockages such as bridging, so that it is thawed within the storage hopper and then connected to the downstream equipment.

Hot water piping is installed horizontally at 30cm intervals in the “W” shaped storage area to thaw frozen food. Food waste has a solids (TS) concentration of about 20% and more than 80% of it is moisture. Therefore, especially in the summer, when a food collection truck dumps food into the storage tank, a large amount of water (leachate) is simultaneously injected into the storage tank. Therefore, if the leachate injected into the storage tank is not immediately drained, the solid food will float and be sent to the lower crushing separator. Since transport is not possible, a perforated net is installed to drain the leachate smoothly.

These perforated nets are circular at each location of the food input hopper 101, have a diameter of ø8mm, the installation interval is 20mm, and the installation length is 2m. It is desirable to install a total of 6 nets, one each at the top, center, and bottom of the food input hopper. do.

The shredding separator 102 is a sorting member that separates coarse foreign substances from food waste installed and stored downstream of the food input hopper 101 through shredding and primary crushing. The food waste stored downstream of the food input hopper 101 is More than 90% of coarse foreign substances larger than 20 mm are sorted through primary crushing and sorting of the waste into broken and perforated mesh sizes of 20 mm or less.

In addition, in this shredding separator 102, the food waste in the food storage tank is transferred to the shredding separator by operating the double screw at the bottom of the food input hopper 101, and the shredding separator 102 moves the food waste in the food storage tank to the shredding separator, and is disposed on the axis at regular intervals on a horizontal screw-type rotating axis. As the hammer is attached to the attached screw blade (KNIFE) and rotates, the food waste inside the volume-rate food fee system bag is pulverized with the hammer, and at the same time, it is initially shredded by the screw blade, and vinyl and plastic of 20 mm or more are crushed through a 20 mm-sized perforated net installed inside the shredding separator. By selecting coarse foreign substances such as wood, wood, iron metal, and animal bones, more than 90% of coarse foreign materials larger than 20 mm are removed.

The secondary shredder 103 is a shredder installed downstream of the shredder and sorter 102 to maintain the particle size below a predetermined level and select foreign substances through secondary shredding of the primary shredded and sorted food waste. The primary shredding and sorted food waste is subjected to secondary shredding with a perforated mesh size of 10 mm or less to maintain the particle size of 10 mm or less and more than 95% of foreign substances to be sorted out.

In addition, this secondary shredder 103 is a facility that performs secondary pretreatment on food waste that has been primary pretreated by removing particle size of 20 mm or less and more than 90% of foreign substances in the shredding separator 102, and is a cylindrical rotational separation type shredder. The type does not require a water addition process, and the shredder has an integrated structure of an impeller and a grinding blade (KNIFE). Input food is shredded to 10 mm or less, and anything larger than 10 mm is shredded through a 10 mm-sized perforated net installed inside the secondary shredder. It is possible to remove more than 95% of impurities by discharging them as foreign substances.

The screw press 104 is a processing member that is installed downstream of the secondary shredder 103 and separates the shredded food waste into dehydrated food cake and food waste water through dehydration to produce inflowable food waste water, and is a secondary shredder. It consists of a 4mm screw press with a perforated mesh that is installed downstream and separates food waste into dehydrated food cake and food waste water through dehydration from the food waste that has been shredded and sorted in two stages to produce food waste water that can be introduced into a three-phase centrifuge.

In addition, in this screw press 104, food waste passes through the gap between the rotor and the drum by the rotation of the screw rotor, and the food waste moves according to the movement of the rotating blades of the conical screw rotor and presses the strainer (STRAINER). ) The solid and liquid are separated through a perforated net (Size 4mm), and the food waste is transferred from the low pressure section to the high pressure section at low speed by the rotating blades of the screw rotor. To increase dehydration efficiency, the main body is driven by a concentrated drum (DRUM). Rotates at low speed (1RPM) and uses a simple shower device to pass liquid food waste water without clogging the perforated mesh, thereby demonstrating high dehydration rate performance with a moisture content of 70% or less. Food dehydration cakes with a moisture content of 70% or less are discharged through the outlet. is discharged.

The second pre-treatment unit 300 is a pre-processing means installed downstream of the oil removal unit 200 to secondarily pre-process food waste. The second pre-treatment unit 300 is a pre-processing unit that is separated from the food dehydration cake generated in the screw press of the first pre-treatment unit and the oil removal unit. The desorbed liquid is mixed evenly and adjusted to 10% TS, and then subjected to fine crushing and fine screening to uniformly remove more than 97% of foreign substances and achieve a particle size of 3 mm or less.

In this second pre-processing unit 300, more than 95% of foreign substances and more than 80% of oil have been removed in the first pre-processing unit and oil removal unit, and the primary processed food waste with a particle size of 10 mm or less is processed through the second pre-processing unit. As a means of final pretreatment under optimal conditions for anaerobic digestion with a particle size of 3 mm or less and a foreign matter selection rate of 97% or more, a food cake mixer (301), a food TS control tank (302), a fine shredder (303), a fine sorter (304), and a syringe are used. It consists of a clone (305) and an intermediate storage tank (306).

The food cake mixer 301 mixes the food dehydration cake separated in the screw press 104 of the first pretreatment unit 100 and the desorbed liquid in the desorbed liquid tank of the three-phase centrifuge of the oil removal unit 200 into the food TS control tank. (302) It is a mixing means to mix evenly before inputting.

This food cake mixer 301 is a horizontal double screw type mixing device that mixes the solid food dehydration cake separated in the screw press 104 and the mixed liquid in the three-phase centrifugal separator tank 203, that is, three-phase centrifuge. The mixed liquid of the solid phase and the liquid phase, excluding the oil separated in the separator 202, moves in the food cake mixer 301 by operating the double screw and is uniformly mixed and transferred to the food TS control tank.

The food TS control tank 302 is a control means installed downstream of the food cake mixer 301 and adjusts TS (Total Solid) to 10% through the valence of the time constant, and controls the food cake mixer 301. Process water, that is, time constant, is added to the first pretreated substrate, in which the food dehydration cake and the mixed liquid in the three-phase centrifuge detachment tank 203 are transferred in a homogenized state through the food cake mixer 301, and TS (Total Solid) concentration is adjusted to 10%, and the first pretreatment substrate is homogenized by operating the vertical vertical stirrer installed at the top of the food TS control tank.

The fine shredder 303 is a shredding means installed downstream of the food TS control tank 302 to shred food waste with a particle size of 10 mm or less in the first pretreatment unit 100 into 3 mm or less. It consists of equipment that crushes the substrates with a particle size of 10 mm or less selected in the preprocessing unit 100 to 3 mm or less. It is manufactured with a cylindrical mixer structure, and a drive motor is installed in the center, so the input substrate is transferred to the drive unit. It is pulverized to 3 mm or less by the rotational force of the blade installed at the top.

This fine crusher (303) operates intermittently and stops for 5 minutes after 10 minutes of operation. During the stop time, the lower outlet automatically opens (OPEN), and the finely crushed substrate of 3 mm or less is sent to the fine separator (304) through the lower connection pipe. ), and while rotating at a speed of 450 RPM per minute, it is pulverized into particle sizes of 3 mm or less.

The fine sorter 304 is a sorting means installed downstream of the fine shredder 303 to selectively remove vinyl and fibrous foreign substances larger than 3 mm from food particles crushed to 3 mm or less and maintain a foreign material removal rate of 96% or more.

This fine sorter 304 is a drum-shaped horizontal cylindrical inclined structure that is pulverized to a particle size of 3 mm or less in a fine crusher, and is a facility that ultimately removes suspended foreign substances from the pretreated substrate from which more than 95% of all foreign substances have been removed. Consisting of a gap between the incoming substrates and the rotating screen (3mm), food items smaller than 3mm fall downwards due to gravity. Contaminants larger than 3mm are caught on the surface of the rotating screen and moved to the slanted bottom to be discharged. The substrates pass through a fine separator. My foreign matter removal rate remains above 96%.

The cyclone 305 is installed downstream of the fine sorter 304 and removes fine inorganic substances (FS, Fixed Solid) such as silt, crushed eggshells, and crushed shellfish, maintaining the foreign matter removal rate in the substrate at more than 97%. It is a means of separation.

This cyclone 305 uses a swirling flow to target pulverized food with a total foreign matter removal rate of 96% or more and a particle size of 3 mm or less through the fine separator 304 to remove soil, sand, and crushed eggshells with a particle size of 3 mm or less. It consists of a device that removes fine inorganic substances (FS) such as crushed shells, and the foreign matter removal rate of food waste passing through the cyclone 305 maintains the optimal anaerobic digestion status of over 97%.

In particular, the cyclone 305 refers to a swirling flow type dust collector that removes fine particles in a commonly used gas using a swirling flow. Food waste that has been pretreated with a particle size of 3 mm or less and a foreign matter removal rate of 96% or more is classified into a cyclone. It is injected horizontally into the cyclone body on the upper wall, generating a swirling flow, removing fine inorganic substances, and transferring them to the intermediate storage tank at the downstream through the upper piping of the cyclone with a final foreign matter removal rate of 97% or more and a particle size of 3 mm or less.

The intermediate storage tank 306 is installed downstream of the cyclone 305 to remove more than 97% of the foreign substances contained in the food waste and to uniformly pre-treat the particle size to 3 mm or less. Temporarily before inputting it into the anaerobic digestion unit 400. It is a means of storage.

This intermediate storage tank 306 completely removes foreign substances and oil through all pretreatment processes such as crushing, screening, and oil removal, maintaining a foreign matter removal rate of 97% or more and an oil removal rate of 80% or more, and pretreating the particle size to 3 mm or less. It consists of a facility that temporarily stores food waste before putting it into the digester.

In addition, the size of the intermediate storage tank 306 is installed with a capacity that can stay for 3 days, which is 3 times the daily intake. The intermediate storage tank 306 is divided into three storage areas by installing a wall in the center, and the height of the upper part of the wall is It is set 30cm below the water level to allow pre-treated food to move through the upper part of each retention zone, and a vertical axle-type agitator is installed in each retention zone to achieve complete mixing.

When pouring concrete, each corner of the bottom of the intermediate storage tank is gently rounded, and the concrete is poured at a 1:1 slope and placed at a height of 30cm or more, thereby preventing the occurrence of dead space during agitation.

The oil removal unit 200 is installed downstream of the pretreatment unit and is an oil removal means that separates and removes the oil content of food waste using a three-phase centrifuge. It is installed downstream of the first pretreatment unit 100 and removes the separated food waste water. Oil removal rate of more than 80% is removed through a three-phase centrifuge equipped with a low-speed solid-liquid separator, anisotropic screw blades, and an oil-water separation diaphragm.

This oil removal unit 200 includes a low-speed solid-liquid separator 201, a three-phase centrifugal separator 202, a three-phase centrifugal separator tank 203, an oil tank 204, an oil purification tank 205, and an oil storage tank. It consists of (206).

The low-speed solid-liquid separator 201 is a separation means for separating coarse foreign substances of 4 mm or more contained in the food waste water from the food waste water separated in the pretreatment unit, and removes the foreign matter contained in the food waste water from the food waste water separated in the first pretreatment unit 100. A perforated net of 2 to 2.5 mm is provided to separate coarse foreign substances larger than 4 mm and increase the oil removal efficiency of the three-phase centrifuge.

This low-speed solid-liquid separator (201) separates food dehydration cake and liquid food waste water in a screw press, and coarse foreign matter (mostly fibrous) of 4 mm or more that escapes the 4 mm perforated mesh by the pressure of the screw press is added to the separated food waste water. To increase the oil removal efficiency of the three-phase centrifuge, a low-speed solid-liquid separator is installed in front of the three-phase centrifuge.

In addition, the low-speed solid-liquid separator (201) is a device that separates coarse foreign substances of 4 mm or more contained in food waste water, such as fiber, using a low-speed centrifugal force of about 250 RPM. A cylindrical discharge net of 2 to 2.5 mm is installed to separate solid foreign substances. As a centrifugal equipment that separates and filters the liquid and liquid phases, the food waste water from which foreign substances are removed in the low-speed solid-liquid separator (201) is temporarily stored in the food waste water storage tank and then transferred to the three-phase centrifuge (202) by operating the transfer pump. .

The three-phase centrifuge 202 is a separation means installed downstream of the low-speed solid-liquid separator 201 and removes more than 80% of the oil by centrifuging it into three phases of solid, liquid, and oil using centrifugal force, as shown in Figures 4 to 4. As shown in FIG. 6, it is provided with non-equally spaced screw blades (202-3) and an oil-water separation plate (202-2).

This three-phase centrifuge (202) is installed downstream of the low-speed solid-liquid separator (201), uses centrifugal force, and has screw blades (202-3) at equal intervals to increase the centrifugal efficiency of the three phases of solid, liquid, and oil. By applying the oil-water separation plate (202-2), more than 80% of oil is removed.

In addition, the three-phase centrifugal separator 202 uses a high-speed centrifugal force of 3,000 RPM and the difference in sedimentation speed due to the difference in specific gravity to separate the three phases of solid, liquid, and oil into solid dehydrated food, liquid desorbed liquid, and liquid phase. Separated into oil.

This three-phase centrifuge (202) improves the existing equally spaced screw blades (202-3) to increase the separation efficiency with an oil removal rate of more than 80%, and installs a small blade (oil cell guide) up to the second blade at the substrate inlet. This is a structure that increases the residence time of the incoming substrate by maintaining the boiling interval and increases oil removal efficiency by applying the oil-water separation plate (202-2).

During three-phase centrifugation, solids are dehydrated while being transferred to the cone (slope) of the bowl by the screw blade and discharged through the sludge discharge port, and the remaining two types of liquid, such as desorbed liquid and oil, are separated into different flange forms on the opposite side. It is separated and discharged through the outlet at the water level.

Of these, the deliquid is discharged from the liquid outlet of the bowl flange to the treated water outlet formed close to the bottom of the bowl, and the oil is discharged through a specially designed oil-water separation diaphragm (202-2).

The three-phase centrifugal separator liquid tank 203 is installed on one side downstream of the three-phase centrifugal separator 202, stores the solid matter and liquid liquid separated from the three-phase centrifuge 202, and releases them through a vertical shaft stirrer. It is a tank member that maintains uniform concentration.

This three-phase centrifugal separator liquid tank 203 is a vertical cylindrical or square steel structure made of SS41 or higher, which is a general structural rolled steel, and stores the solid matter and liquid liquid separated from the three-phase centrifuge and uses a vertical vertical axis stirrer. This maintains the concentration uniformly.

The oil tank 204 is a storage means installed on the other side downstream of the three-phase centrifuge 202 to temporarily store the oil separated from the three-phase centrifuge 202, and is a vertical cylindrical or made of SS41 or higher, which is a general structural rolled steel. It has a square steel structure and temporarily stores the oil separated from the three-phase centrifuge (202).

The oil purification tank 205 is installed downstream of the oil tank 204 and is a removal means for removing foreign substances such as moisture in the oil by heating the recovered oil with a heating coil built into the oil tank 204. By heating the heating coil, foreign substances such as moisture in the oil are removed, ensuring quality that can be sold externally.

This oil purification tank 205 has a vertical cylindrical structure made of SS41 or higher, a rolled steel for general structural purposes, and the recovered oil is removed from the oil by heating the heating coil built into the oil tank 204 to remove foreign substances such as moisture in the oil. It becomes possible to secure quality that can be sold.

The oil storage tank 206 is installed downstream of the oil purification tank 205 and is a storage means for temporarily storing the oil produced in the oil purification tank 205. The oil produced in the oil purification tank 205 is sold to external parties. It consists of an oil storage tank with a built-in heating coil for temporary storage.

This oil storage tank 206 is manufactured in a vertical cylindrical shape made of SS41 or higher, a rolled steel for general structural purposes, and is a facility for temporarily storing oil produced in the oil purification tank downstream of the oil purification tank for external sale, in preparation for an emergency. It consists of a structure with a built-in heating coil.

The anaerobic digestion unit 400 is installed downstream of the oil removal unit 200 and is an anaerobic digestion means for anaerobic digestion of food waste. It is installed downstream of the second pretreatment unit 300 and performs anaerobic digestion with the acid fermentation tank 401. It consists of a digester (402), and the substrate that has been pretreated to remove more than 97% of foreign substances, have a particle size of 3mm or less, and remove more than 80% of oil, is introduced into the digester under the condition of OLR (organic load rate) of 2.5kgVS/m ³ ·d to remove organic substances. This is decomposed, and ORP (oxidation reduction potential), pH meter, thermometer, pressure gauge, etc. are installed to enable real-time analysis for monitoring the anaerobic digestion tank.

This anaerobic digestion unit 400 consists of an acid fermentation tank 401 and an anaerobic digestion tank 402. After the substrate for which food waste pretreatment has been completed in the second pretreatment unit 300 is transferred to the anaerobic digestion unit 400, organic matter is It is a facility that produces biogas by decomposition. It is a two-phase anaerobic digestion system in which the acid fermentation tank and the anaerobic digestion tank are separated. The anaerobic digestion tank (402) is equipped with a pH and ORP (oxidation reduction potential) meter, a thermometer and pressure gauge, a safety valve, and a flashback preventer. It includes a FeCl ₃ injection facility to remove primary hydrogen sulfide (H ₂ S) in biogas, a digester tank overflow induction facility to eliminate the overflow phenomenon of the digestate liquid in the tank, and removal of foreign substances floating in the top. It includes a scum removal device for anaerobic digestion, a cyclone to remove foreign substances from the bottom, a vertical vertical axis mechanical stirrer and baffle for complete mixing and agitation in the digester, and increases the activity of anaerobic microorganisms when the operating conditions of the anaerobic digestion tank worsen. It consists of a trace element storage tank that supplies trace elements (Co, Ni) to the anaerobic digestion tank.

This anaerobic digestion unit 400 is installed downstream of the second pretreatment unit 300 and preprocessed substrates (TS 10%, particle size 3mm or less, foreign matter removal rate 97% or more, oil removal rate 80% or more) are treated under anaerobic conditions. It is a facility that produces biogas by decomposing organic matter through the decomposition action of anaerobic microorganisms. The anaerobic digestion unit is a separate two-phase anaerobic digestion system in which the acid fermentation tank and anaerobic digestion tank (methane fermentation tank) are installed as separate structures. In the acid fermentation tank, the pretreated substrate undergoes hydrolysis and acid fermentation (including acetic acid fermentation), and carbohydrates, proteins, and fats are converted into propionic acid, butyric acid, and ethanol through amino acids, sugars, and fatty acids, and then through acetic acid fermentation, acetic acid, H ₂ , A change reaction to CO ₂ is involved, and the retention time (HRT, Hydraulic Retention Time) at this time does not exceed a maximum of 3 days. Anaerobic digestion tanks (methane fermentation tanks) are produced by the action of hydrogen-utilizing methanogens (Hydrogenotrophic methanogens: MMB (Methanomicrobiales), MBT (Methanobacteriales), etc.) and acetic acid-utilizing methanogens (Acetoclastic methanogens: MSC (Methanosarcinaceae), MST (Methanosaetaceae), etc.) This is a facility that produces biogas (CH ₄ 60%, CO ₂ 40%), and the organic loading rate (OLR) supplied through the acid fermentation tank is maintained at 2.5 kgVS/m ³ ·d through automatic control. The inlet substrate TS concentration is 10%, and the anaerobic digestion tank (methane fermentation tank) operating temperature is 36 ± 0.5°C, which is medium temperature digestion conditions.

In addition, the anaerobic digestion tank 402 has a FeCl ₃ injection facility for removing primary hydrogen sulfide (H ₂ S) in biogas, and when a sudden gas is generated in the anaerobic digestion tank, the digestion liquid overflows into the biogas purification unit 500. ) It includes a digester tank overflow induction equipment to resolve the phenomenon, a scum removal device to remove upper floating foreign matter such as scum, and a cyclone to remove fine foreign matter at the bottom, and a vertical vertical axis mechanical stirrer for complete mixing and agitation in the digester. It is a high-efficiency anaerobic digestion tank that includes a baffle.

In particular, when 550 ppm of FeCl ₃ is injected into the digester, the H ₂ S concentration in biogas can be reduced from 2,000 ppm to 500 ppm or less, so primary desulfurization occurs in the anaerobic digester, and at the same time, the amount of biogas generated increases.

In addition, as a result of an experiment analyzing the change in biogas generation before and after the injection of FeCl ₃ , it was confirmed that the amount of biogas generation increased by more than 15% with the injection of FeCl ₃ . In addition, the heating of the anaerobic digestion tank (402) is performed by heat exchanging hot water (90°C) produced in the co-fired boiler of the biogas purification unit (500) in a double-tube heat exchanger to set the temperature of the acid fermentation tank and the anaerobic digestion tank to 36 ± 0.5°C, respectively. will be maintained.

The substrate flowing into the anaerobic digestion tank (402) undergoes a multi-stage crushing and selection process in the first pretreatment unit (100), oil removal unit (200), and second pretreatment unit (300) to remove more than 97% of foreign substances and reduce the particle size to 3mm. Hereinafter, the oil removal rate is maintained at more than 80%, but about 3% of foreign substances not removed in the pretreatment process consist of floating foreign substances with a particle size of 3 mm or less and settled fine incombustibles.

Among these, suspended fine foreign substances less than 3 mm (vinyl, seeds, red pepper powder, sesame seeds, fiber, etc.) and a small amount of oil not removed in the oil-water separator of the pre-treatment unit combine at the top of the digester during long-term operation of the anaerobic digestion tank, forming scum. Since there is a possibility of formation of scum, the scum removal device installed at the top of the anaerobic digestion tank is installed for the purpose of simultaneously removing suspended fine foreign matter and oil of 3 mm or less, and the removed foreign material is transferred to the digestion filtrate storage tank.

The digester overflow inducing facility installed at the top of the anaerobic digestion tank (402), that is, 30 cm above the installation location of the scum removal device, does not allow biogas generated in the anaerobic digestion tank to be discharged smoothly, causing volcanic explosions and When a simultaneous discharge phenomenon occurs (occurring due to the inflow of a large amount of toxic substances into the digester or lack of smooth agitation of the digester), the digestion filtrate is transferred to the biogas purification unit 500 at the rear end due to the occurrence of the digestion tank overflow phenomenon. As the outflow may contaminate the biogas purification unit 500, causing the entire facility to stop operating, contamination of the biogas purification unit 500 can be prevented by installing a digester overflow induction facility when the overflow phenomenon occurs. The digester overflow inducing facility pipe is connected to the digestion filtrate storage tank.

In order to increase the organic matter removal rate through effective contact between methane-producing bacteria (Hydrogenotrophic Methanogen, Acetoclastic Methanogen) and organic substances through complete mixing of the substrates introduced into the anaerobic digestion tank 402, an organic material removal rate is installed at the top of the digester. A vertical vertical axis mechanical stirrer and three baffles are installed at the bottom.

The wings of the vertical axis mechanical stirrer are installed in three stages on the vertical axis. The wings are oriented in the same direction for the first and third stages, and the wings for the second stage are installed in the opposite direction to the first and third stages, thereby increasing the mixing efficiency according to the operation of the stirrer. , the baffle allows horizontal agitation by the stirrer to collide with the baffle, enabling up and down agitation at the same time, thereby improving agitation efficiency and eliminating dead space in the digester through complete mixing, thereby maintaining an optimal anaerobic digestion state.

In addition, food waste does not contain trace elements such as Co, Ni, etc. or exists in trace amounts, so when the anaerobic digestion tank is operated for a long period of time, a trace element deficiency phenomenon occurs and the operating condition of the anaerobic digestion tank suddenly deteriorates (organic acid accumulation of 4 g/L or more, pH). If the condition (maintaining the condition below 6.5, etc.) occurs, the input of the substrate itself must be stopped. However, due to the fact that food waste brought in every day must be processed, a trace element storage tank was installed to improve the operating condition of the anaerobic digestion tank, and Co and Ni 1mg/min as trace elements are installed. By building a facility that can mix the L concentration equally at a 1:1 ratio and inject it into the digestion tank, it becomes possible to respond immediately even in the event of an abnormal situation in the anaerobic digestion tank.

In addition, an ORP meter and a pH meter that can measure ORP and pH in real time are installed in the anaerobic digestion unit 400, and a PLC (Programmable Logic Controller) system is operated in the central control room to measure ORP and pH values according to the amount of input substrate that has been processed. Of course, it is also possible to automatically measure and transfer to the central control room, and to automatically control the operation to increase or decrease the amount of input substrate by analyzing the measured values in the PLC program.

The biogas purification unit 500 is a biogas purification means installed on one side of the anaerobic digestion unit 400 to purify the biogas discharged from the anaerobic digestion unit 400, and is produced in the anaerobic digestion unit 400. It is a biogas purification means that removes foreign substances such as moisture, hydrogen sulfide, and siloxane contained in biogas and separates CO ₂ and H ₂ from purified biogas.

This biogas purification unit 500 includes a purification facility for purifying moisture, hydrogen sulfide, and siloxane, which are impurities in the biogas produced in the anaerobic digestion unit 400, and a membrane facility for separating CO ₂ in the biogas after purification. It includes a steam reforming facility that produces hydrogen with a purity of 99% or more from biomethane and biomethane through a steam reforming reaction, and a co-fired boiler and double-tube heat exchanger to use purified biogas as a substitute for LNG.

The biogas purification unit 500 includes a primary desulfurization facility, a water separator 501, a biogas dehumidifier 502, a gas filter 503, a dry desulfurization facility 504, a siloxane removal facility 505, and a gas storage tank ( 506), a membrane facility (507), a steam reforming facility (508), a co-fired boiler (509), and a double-tube heat exchanger (510).

The primary desulfurization facility is a desulfurization means that first removes high concentration hydrogen sulfide contained in biogas by injecting FeCl ₃ into the anaerobic digestion tank 402 of the anaerobic digestion unit 400, and injecting FeCl ₃ into the anaerobic digestion tank to produce biogas. The high concentration of hydrogen sulfide contained within is first removed.

The water separator 501 is a separation means that primarily removes moisture in the biogas by a swirling flow method. It is a vertical cone-shaped cyclone type and is made of STS 304, and the ratio of the diameter of the cone to the length of the vertical part is 1: 4, the biogas containing moisture flows into the upper side of the cone and collides with the inside of the water separator due to rotational force, thereby removing the moisture to the bottom.

The lower part of the water separator 501 is equipped with an automatic valve, and the valve opens and closes at 5-minute intervals to discharge the moisture removed from the water separator 501, and the water removed from the water separator 501 is stored in the digestion filtrate storage tank 601. will be transferred to.

The biogas dehumidifier 502 is a removal means that is installed downstream of the water separator 501 and secondarily removes moisture by cooling the water that was primarily removed. In the water separator 501, more than 70% of the moisture is removed from the water separator 501. It consists of a device that secondarily removes moisture contained in biogas by cooling it in the removed state, and the moisture removal rate is over 99%.

In this biogas dehumidifier 502, the wet-saturated biogas first removed from the air-water separator 501 is introduced into the biogas dehumidifier and indirectly cooled as chilled water to condense the moisture to 1% or less. It is a removal equipment.

The gas filter 503 is a filter member installed downstream of the biogas dehumidifier 502 to thirdly remove fine dust and mist-like moisture in biogas using a filter, and removes fine dust and moisture contained in biogas. It is a device that simultaneously removes the Produced in format.

The material of this gas filter 503 is polypropylene, which is characterized by alkali resistance, acid resistance, and excellent abrasion resistance. The gas filter pore size is 0.1㎛, and the moisture removal rate in biogas after passing through the gas filter is is over 99.5%, and the dust concentration is maintained below 10mg/N㎥.

The dry desulfurization facility 504 is a desulfurization facility installed downstream of the gas filter 503 to secondarily remove hydrogen sulfide in the biogas first removed in the anaerobic digestion tank 402. It is installed downstream of the gas filter 503. It consists of a facility that adsorbs and oxidizes H ₂ S by passing biogas through a desulfurization tower filled with a desulfurization agent containing iron oxide (Fe ₂ O ₃ ).

In this dry desulfurization facility 504, 550ppm of iron salt (FeCl ₃ ) is first injected from the FeCl ₃ injection facility into the anaerobic digestion tank to remove H ₂ S contained in biogas, thereby reducing the concentration of hydrogen sulfide in biogas from 2,000 ppm to 500 ppm or less. As the primary desulfurization progresses, the hydrogen sulfide concentration can be removed to 10 ppm or less in the secondary dry desulfurization facility, so the impact of corrosion due to hydrogen sulfide on the rear co-fired boiler, etc. is minimal, enabling stable operation of the biogas purification unit (500). In addition, it is possible to reduce construction costs by 40% and operating costs by more than 5% compared to wet desulfurization facilities, providing the effect of securing the economic feasibility of dry desulfurization facilities.

The siloxane removal facility 505 is installed downstream of the dry desulfurization facility 504 and removes siloxane in biogas using the adsorption function of activated carbon. It removes siloxane contained in biogas using the adsorption function of activated carbon. Siloxane, an organosilicon compound, is converted into silica (SiO ₂ ) by combustion and is in a powder or crystalline state, causing damage to major equipment such as boilers, wear and clogging, and stoppage of operation. Therefore, it is removed to less than 0.03 mg/m ³ through siloxane removal equipment.

The gas storage tank 506 is a storage tank installed downstream of the siloxane removal facility 505 to temporarily store biogas from which moisture, hydrogen sulfide, and siloxane have been removed. The residence time is more than 6 hours of the daily average generation amount, and is a double membrane It is a double membrane type gas storage tank and consists of a permanent structure supported by air pressure.

The membrane facility 507 is installed downstream of the gas storage tank 506 and uses a membrane to separate the biogas temporarily stored in the gas storage tank 506 from the difference in permeation rates between CH ₄ and CO ₂ in the membrane. This is a facility that separates CO ₂ and produces biomethane containing more than 98% CH ₄ .

This membrane facility 507 is installed downstream of the gas storage tank 506 and undergoes a refining process to remove moisture, hydrogen sulfide, and siloxane, and then separates CO ₂ from the biogas temporarily stored in the gas storage tank to produce CH ₄ 98 As a facility that produces more than % biomethane, a microporous polymer hollow fiber membrane module (polysulfone polymer hollow fiber membrane module) is used.

When the mixed gas of CH ₄ and CO ₂ passes through the hollow fiber membrane module, CO ₂ , which has high solubility, small molecular weight, and fast diffusion rate, has high solubility and a fast diffusion rate due to a selective permeation phenomenon according to the absorption and diffusion mechanism in the membrane inside the hollow fiber. It passes through the inside of the yarn and is separated as a permeating gas on the inner wall of the hollow fiber. CH ₄ , which has low solubility, high molecular weight, and slow diffusion rate, passes through the inside of the hollow fiber and is separated.

In addition, in order to increase the CH ₄ recovery rate and purity, the membrane facility (507) is composed of 3 stages, and CH ₄ is input into the 2nd stage, producing CH ₄ with a purity of more than 98% through secondary separation. , the permeated gas (main component of CO ₂ ) separated in stage 1 is inputted to stage 3 to separate CO ₂ , and the gas containing some CH ₄ is transferred to stage 1 to be recycled, and the permeated gas (main component of CO ₂ ) generated in stage 2 is ) In addition, by recycling and utilizing it in the first stage, the CH ₄ recovery rate is maintained at over 95%.

The steam reforming facility 508 is installed at the rear of the membrane facility 507 and produces more than 99% of H ₂ through a steam reforming reaction from biomethane from which CO ₂ has been separated and removed.

This steam reforming facility 508 is a steam reformer installed at the rear of the membrane facility 507 to produce H ₂ through a steam reforming reaction from biomethane from which CO ₂ has been separated and converted into CH ₄ CH ₄ is converted into synthesis gas, which is a mixed gas of H ₂ and CO, through a steam reforming reaction by reacting with steam at a relatively high temperature (600-800°C), and water vapor is added to CO to convert CO back into H ₂ As the water gas conversion reaction proceeds, additional H ₂ and CO ₂ are generated. Finally, the generated gas is separated and purified to produce high purity H ₂ .

CH ₄ + H ₂ O(+Heat) → 3H ₂ + CO (Steam Reforming Reaction, SMR (Steam Methane Reaction))

CO + H ₂ O → H ₂ + CO ₂ (Water Gas Shift Reaction)

The final H ₂ produced can be used in hydrogen charging stations and fuel cell power generation.

The waste treatment unit 600 is a waste treatment means installed on the other side of the anaerobic digestion unit 400 and processes the waste discharged from the anaerobic digestion unit 400. After decomposition, the remaining digested filtrate is separated into solid and liquid through a centrifugal dehydrator, and the separated solid dehydrated cake is dried in a sludge drying facility to produce dried product.

Sixthly, this waste treatment unit 600 stores the digestion filtrate after the decomposition of the incoming substrate is completed through the anaerobic digestion unit 400, and dehydrates the digestion filtrate to produce solid dehydrated cake and The dehydrated cake, which is solid after being separated into liquid filtrate, is a post-processing means for producing dried material in a sludge drying facility, including digestion filtrate storage tank (601), centrifugal dehydrator (602), dehydration cake storage tank (603), and sludge drying. It consists of facilities (604).

The digestion filtrate storage tank 601 is a storage means for temporarily storing the digestion filtrate generated in the anaerobic digestion unit 400. The storage capacity is more than 3 days and is composed of 3 or more stages so that digested sludge can be normally stored even when cleaning the 1st stage. It has a structure that can be used to maintain complete mixing using a vertical vertical mechanical stirrer.

In addition, the digestion filtrate storage tank 601 is gently rounded at each corner of the lower part, that is, concrete is poured at an incline of 1:1, and the height is formed to be more than 30 cm, so that no dead space is created during stirring and complete mixing is achieved. It is installed in a structure that allows this.

The centrifugal dehydrator 602 is a facility installed downstream of the digestion filtrate storage tank 601 to separate the stored digestion filtrate into solid and liquid. In the centrifugal dehydrator installed at the rear of the digestion filtrate storage tank 601, the digestion filtrate is separated into solid and liquid and solid phase. The moisture content of the solid dehydrated cake can be maintained at 80%.

The dehydrated cake storage tank 603 is a storage tank for temporarily storing the solid dehydrated cake separated from the centrifugal dehydrator 602. It consists of equipment for temporarily storing the solid dehydrated cake separated from the centrifugal dehydrator 602. It is advisable to keep the dosage for at least 3 days.

The sludge drying facility 604 is a drying facility that produces dehydrated cake with a moisture content of 80% temporarily stored in the dehydrated cake storage tank 603 into dried product with a moisture content of 10% or less using a heat source of biogas. Using the temporarily stored dehydrated cake, dried material is produced through moisture evaporation in a belt-type sludge dryer by supplying hot air, and the produced dried material can be supplied to a coal-fired power plant for use.

The wastewater treatment unit 700 is a wastewater treatment means installed downstream of the waste treatment unit 600 to treat wastewater discharged from the waste treatment unit 600. The liquid desorbed filtrate separated during the centrifugal dehydration process of the waste treatment unit 600 will be processed.

This wastewater treatment unit 700 is a wastewater treatment facility that processes liquid wastewater separated in the centrifugal dehydrator of the waste treatment unit 600 to T-N (total nitrogen) of 250 mg/L or less and T-P (total phosphorus) of 30 mg/L or less. It consists of a storage tank (701) and a wastewater treatment facility (702), and the wastewater treatment facility (702) includes a rapid mixing tank (702-1), a slow mixing tank (702-2), a pressurized flotation tank (702-3), Pre-treatment tank (702-4), denitrification tank (702-5), aeration tank (702-6), MBR (702-7), linked treatment tank (702-8), wastewater sludge storage tank (702-9), centrifugal It consists of a dehydrator (702-10).

The desorbed liquid storage tank 701 is a facility that temporarily stores the liquid desorbed filtrate separated from the centrifugal dehydrator 602 of the waste disposal unit 600. The storage capacity is set to be at least 3 days, and is installed separately in three stages to clean one stage. It has a structure that can store normal desorbed filtrate even during operation, and the stirring method is equipped with a vertical vertical axis mechanical stirrer that allows complete mixing.

Like the digestion filtrate storage tank, this deliquency storage tank 701 is gently rounded at each corner of the bottom of the storage tank, that is, concrete is poured at a 1:1 slope, and the height is more than 30cm, so that no dead space is created during stirring. Of course, it is possible to produce a structure that allows complete mixing.

The rapid mixing tank (702-1) is installed downstream of the desorbed liquid storage tank (701) via a transfer pump, and is a mixing tank that reacts fine sludge with chemicals by adding polymer (PAC) and NaOH. ) is transferred to the rapid mixing tank (702-1) by a transfer pump, and a heat exchanger is installed at the front of the rapid mixing tank to maintain the winter temperature at 40℃. Polymer (PAC) and NaOH are input into the rapid mixing tank to produce fine sludge. reacts with the drug.

This rapid mixing tank (702-1) is transferred from the desorption liquid storage tank 701 to the reaction tank by a transfer pump, and a heat exchanger is installed at the front of the reaction tank to maintain the winter temperature at 40°C. The rapid mixing tank contains polymer (PAC) and NaOH is added and the fine sludge is mixed with the chemical through rapid stirring using a vertical shaft stirrer.

The slow mixing tank (702-2) is a mixing tank that forms sludge floc by slow agitation using chemicals introduced from the rapid mixing tank (702-1), and desorbs the chemicals (polymer, NaOH) added from the reaction tank. The filtrate forms a sludge floc through slow agitation, and the agitation is performed using a vertical axis agitation method, which consists of two tanks to increase the coagulation effect.

The pressurized flotation tank (702-3) levitates the floc formed in the slow mixing tank (702-2) by injecting fine air (30-100 μm), and removes suspended solids using the flotation sludge removal facility at the top. As a treatment tank, the floc formed in the flocculation tank is floated by fine air injection (30-100 μm) from an air diffuser installed at the bottom of the pressurized flotation tank, and suspended solids are removed by the upper flotation sludge removal device.

The pre-treatment treatment tank (702-4) is installed at the rear of the pressurized flotation tank (702-3) to first remove organic substances and suspended substances in the wastewater and then adjust and equalize the flow rate before inputting it into the nitrogen and phosphorus removal process at the rear. As a treatment tank, it is a facility for first removing organic substances and suspended substances in the wastewater and then adjusting and equalizing the flow rate before inputting it to the subsequent nitrogen and phosphorus removal process. It is composed of two tanks, and a vertical axle-type agitator is installed in each tank, and the bottom of the storage tank is Each corner is gently rounded, that is, the concrete is poured at a 1:1 slope, and the height is more than 30cm, so that no dead space is created during stirring and the structure is completely mixed.

The denitrification tank 702-5 is installed at the rear of the pretreatment water tank 702-4 and is transported by a transfer pump to remove nitrogen. An external carbon source is supplied and a submersible mixer is installed to increase nitrogen removal efficiency through stirring. As a treatment tank for increasing the wastewater, after suspended solids are removed in the pressurized flotation tank (702-3), the wastewater is transferred to the denitrification tank by a transfer pump through the pretreatment treatment tank (702-4) to remove nitrogen. The residence time in the denitrification tank is 2 hours, an external carbon source is supplied, and the nitrification solution is circulated to the denitrification tank through internal return of wastewater that has completed nitrification from the aeration tank (internal return rate 100%). A submersible mixer is installed in the denitrification tank. Stirring in water contributes to increasing nitrogen removal efficiency.

The aeration tank 702-6 is a treatment tank installed downstream of the denitrification tank 702-5 to change ammonia nitrogen into nitrate nitrogen via nitrite nitrogen. The aeration tank 702-6 is a treatment tank that converts ammonia nitrogen into nitrate nitrogen via nitrite nitrogen. An aeration tank that converts nitrogen into nitrogen is installed, and the aeration tank is divided into two tanks. NaOH for pH adjustment is added to aeration tank A, and the nitrified wastewater in aeration tank B is transferred to the denitrification tank by operating an internal return pump, and aeration tank A is ,B Both have a diffuser installed at the bottom for air supply.

This aeration tank (702-6) is installed downstream of the denitrification tank (702-5) and converts organic nitrogen and ammonia nitrogen (NH ₄ -N) into nitrate nitrogen (NO) via nitrite nitrogen (NO ₂ -N). Nitrification changes to ₃ -N), and the aeration tank residence time is 6 hours and is divided into two tanks. NaOH for pH adjustment is added to aeration tank A, and the nitrified wastewater in aeration tank B is operated by the internal return pump. It is transferred to the denitrification tank (internal return rate 100%), and aeration tanks A and B are both equipped with diffuser pipes for air supply at the bottom.

MBR (702-7) is an MBR (Membrane Bio Reactor) installed downstream of the aeration tank (702-6) to further remove organic matter, suspended solids, T-N (total nitrogen), and T-P (total phosphorus) contained in wastewater. , It consists of an external circulation type MBR (External Membrane Bioreactor) that additionally removes organic matter, suspended solids, T-N (total nitrogen), and T-P (total phosphorus) from wastewater.

This MBR (Membrane Bioreactor) is a final facility that removes N and P, including organic substances, through complete solid-liquid separation using a UF (Ultrafiltration Membrane) hollow fiber membrane. It is an external circulation MBR system rather than an immersion type, and provides chemical cleaning compared to the immersion type. Not only is it very easy to clean in place or replace the membrane module, but by installing only a drain line, the performance and lifespan of the membrane module can be increased by periodically cleaning a small amount of chemicals every day, thereby increasing the membrane module performance and lifespan. Since the amount of aeration inside can be minimized and the circulating flow rate can be reduced, it is very excellent in terms of energy efficiency.

The linked treatment tank (702-8) is installed downstream of the MBR (702-7) and connects treated water treated to a final T-N (total nitrogen) of 250 mg/L or less and T-P (total phosphorus) of 30 mg/L or less to a sewage treatment plant. As a treatment tank, it is installed downstream of MBR and is a temporary storage tank for linked treatment to a sewage treatment plant for treated water that has been treated to a final T-N (total nitrogen) of 250 mg/L or less and T-P (total phosphorus) of 30 mg/L or less.

The wastewater sludge storage tank (702-9) is a storage tank installed downstream of the pressure flotation tank (702-3) to process the flotation sludge generated in the pressure flotation tank (702-3). The storage tank is divided into two tanks, 1 The facility can be operated even during renovation and cleaning. A vertical axle-type agitator is installed as the agitation method, and each corner of the lower part of the storage tank is gently rounded. In other words, concrete is poured at a 1:1 slope and the height is more than 30cm to be used during agitation. Install in a structure that allows complete mixing without creating space.

The centrifugal dehydrator (702-10) is a dehydrator installed downstream of the pressure flotation tank (702-3) to treat flotation sludge generated in the pressure flotation tank (702-3), and separates sludge from the wastewater sludge storage tank into solid and liquid. The dehydrated liquid separated from the centrifugal dehydrator is transferred to the desorbed liquid storage tank for processing, and the solid dehydrated cake is transferred to the sludge drying facility with a moisture content of 80%, and then the dried product is produced to be used as auxiliary fuel for a coal-fired power plant. It will be used.

Therefore, the oil removal device of the present invention is used in anaerobic digestion operations such as the generation of scum and overflow phenomenon in the digester due to oil (normal hexane extract material) contained in food waste or food wastewater. This relates to a device that increases oil removal efficiency by improving the screw blade shape of the existing three-phase centrifuge and applying an oil-water separation diaphragm in order to remove more than 80% of oil that has a negative impact before entering the digester. It crushes and sorts the brought in food waste. The first pretreatment unit 100 produces food waste water that can be introduced into a three-phase centrifuge by first pre-treating more than 95% of foreign substances and having a particle size of 10 mm or less and then separating it into dehydrated food cake and food waste water through dehydration. An oil removal unit (200) that removes more than 80% of oil from the food wastewater through a three-phase centrifuge equipped with a low-speed solid-liquid separator, anisotropic screw blades, and an oil-water separation diaphragm, and dehydration of food generated in the screw press of the first pretreatment unit. The cake and the desorbed liquid separated from the oil removal unit 200 are mixed equally, adjusted to 10% TS, and then subjected to fine crushing and fine screening to remove more than 97% of foreign substances and perform secondary pretreatment to uniformly reduce the particle size to 3 mm or less. It consists of a pretreatment unit 300, an acid fermentation tank, and an anaerobic digestion tank, and the substrate that has been pretreated to remove foreign substances (more than 97%), have a particle size of 3 mm or less, and remove oil more than 80% is subjected to OLR (organic loading rate) of 2.5 kgVS/m ³ ·d. Organic substances are decomposed upon entering the digester under certain conditions, and an anaerobic digestion unit 400 is equipped with an ORP (oxidation reduction potential), pH meter, thermometer, and pressure gauge capable of real-time analysis, and the anaerobic digestion unit 400 produces A biogas purification unit 500 that removes foreign substances such as moisture, hydrogen sulfide, and siloxane contained in biogas and separates CO ₂ and H ₂ from the purified biogas, and the substrate introduced into the anaerobic digestion tank is decomposed by methanogenic bacteria. After the remaining digestion filtrate is separated from solid and liquid through a centrifugal dehydrator, the separated solid-phase dehydrated cake is dried in a sludge drying facility, and then a waste treatment unit (600) produces dried matter, and a waste treatment unit (600) that processes the liquid separated from this waste treatment unit (600). It consists of a wastewater treatment unit 700, and in the oil removal unit, oil separated in a three-phase centrifuge is heated to increase purity to produce oil products that can be sold.

Hereinafter, the experimental results of property changes including the oil removal rate according to the operation of the three-phase centrifuge of the oil removal unit 200 among the components of the present invention according to the described examples. However, these examples are only for illustrating the present invention. , the scope of the present invention is not limited by the following examples.

<Experimental example> Experiment on property change before and after operation of a 3-phase centrifuge

In order to confirm the change in property change values, including the removal rate of oil (normal hexane extract) before and after operation of the three-phase centrifuge, actual operation was conducted at a 10 ton/hr plant installed in the pretreatment facility of K City's private food waste composting facility. Samples were collected before and after operation of the three-phase centrifuge and laboratory analysis was performed.

Field sampling and laboratory analysis were conducted over two rounds (5 times for each round, 10 times in total), and as shown in Table 1, Table 2, and Table 3, the average oil (normal hexane extract) removal rate was 1. The analysis was as follows: primary (5 measurements) 83.8%, secondary (5 measurements) 90.8%, and overall average (10 measurements) 87.3%.

Compared to the existing 3-phase centrifuge, the oil removal rate achieved an average of 87.3% by applying the anisotropic screw blade and oil-water separation diaphragm, which was 1.7 times more excellent than the 50% oil removal rate of the existing 3-phase centrifuge, making it the 3rd most effective anaerobic digestion for food waste. When applying a centrifugal separator, it is possible to minimize the inflow of oil contained in food waste into the anaerobic digestion tank, thereby eliminating factors that cause abnormal operation problems in the digester, such as non-generation of scum in the anaerobic digester and prevention of digestion tank overflow. It is believed that it will be possible to increase the facility operation rate through safe operation of the anaerobic digestion tank.

In addition, as a result of measuring the change in the properties of each substance before and after operation of the three-phase centrifuge, the TS removal rate was analyzed as 11.7% for the first time (average of 5 times), 37.2% for the second time (average of 5 times), and 24.5% for the overall average. , the VS removal rate was 14.7% for the 1st time (average of 5 times), 41.7% for the 2nd time (average of 5 times), and 28.2% for the overall average, and the BOD removal rate was 49.3% for the 1st time (average of 5 times) and 28.2% for the 2nd time (average of 5 times). The average of 5 times) was analyzed as 55.7%, and the overall average was 52.5%.

The COD _Cr removal rate was 27.1% for the 1st time (average of 5 times), 24.2% for the 2nd time (average of 5 times), and 25.7% on average, and the TOC removal rate was 12.3% for the 1st time (average of 5 times) and 25.7% for the 2nd time (average of 5 times). The TN removal rate was analyzed as 7.9% (average of 5 times) and 10.1% overall average, and the TN removal rate was 14.9% for the first time (average of 5 times), 26.6% for the second time (average of 5 times), and 20.7% for the overall average. Cases were analyzed as 19.2% for the first time (average of 5 times), 18.9% for the second time (average of 5 times), and 19.0% for the overall average.

In particular, in the case of the oil removal rate, the 5th average was 83.8%, which is 1.7 times more excellent than the 50% oil removal rate of the existing three-phase centrifuge. When this three-phase centrifuge is applied to anaerobic digestion of food waste, the oil removal rate contained in the food waste is reduced. Since it is possible to minimize the inflow of oil into the anaerobic digester, the facility operation rate is increased due to safe operation of the anaerobic digester by eliminating factors that cause problems in abnormal operation of the digester, such as non-generation of scum in the digester and prevention of digestion tank overflow. is possible.

As described above, according to the present invention, in order to minimize trouble in the anaerobic digestion process and improve the oil removal rate contained in food waste for stable operation, the oil removal rate was improved by improving the screw blade shape of the existing three-phase centrifuge and applying an oil-water separation diaphragm. Provides an effect that can increase by more than 80%.

In addition, through pre-processing of brought in food waste such as crushing and sorting, more than 97% of foreign substances are removed and the particle size is uniformized to 3 mm or less, and organic substances can be decomposed through a separate two-phase digester configuration. Provides effect.

In addition, organic matter flows into the digester in the range of 2.5kgVS/m ³ ·d of organic matter in the anaerobic digestion tank (methane fermentation tank) and is decomposed. ORP (oxidation reduction potential), pH meter, Thermometers, pressure gauges, etc. are installed to provide the effect of stably and automatically controlling the amount of substrate input through PLC linked control.

In addition, foreign substances such as moisture, hydrogen sulfide, and siloxane in the biogas produced during the anaerobic digestion process are removed, CO ₂ and H ₂ are separated from the purified biogas to maximize biogas utilization, and the digested filtrate that has passed through the anaerobic digestion tank is Solid-liquid separation is performed through a centrifugal dehydrator, and the separated solid phase (dehydrated cake) is dried in a sludge drying facility. The dried product is connected to a coal-fired power plant, and the liquid phase filtrate separated in the residue treatment unit is processed through a wastewater treatment process and then sent to a sewage treatment plant. It provides the effect of optimally utilizing linked by-products.

In addition, the anaerobic digestion technology for food waste by removing the oil contained in the food waste improves the screw blade shape of the existing three-phase centrifuge and applies an oil-water separation diaphragm to remove more than 80% of the oil, eliminating the risk of scum at the top of the digester caused by oil. As pressure rise and overflow within the digester and blockage of pipes due to hardening of oil in winter can be prevented in advance, the anaerobic digester can be operated without trouble, improving facility operation rate through stable operation of the facility and reducing organic matter. As the removal rate increases, it provides the effect of increasing facility operation rate by more than 10% and biogas generation by more than 15% compared to existing technology.

In addition, pre-processed food waste is introduced into the digester under the OLR of 2.5kgVS/m ³ ·d, where organic substances are decomposed. Anaerobic digestion is equipped with ORP, pH meter, thermometer, and pressure gauge that enable real-time analysis for monitoring the anaerobic digestion tank. The system and automatic control enable unmanned automatic operation of the facility, providing the operator of the anaerobic digestion facility with the effect of being able to use it as a facility operation manual.

The present invention described above can be implemented in various other forms without departing from its technical idea or main features. Therefore, the above embodiment is merely an example in all respects and should not be construed as limited.

100: first preprocessing unit
200: Oil removal unit
300: Second preprocessing unit
400: Anaerobic digestion unit
500: Biogas purification unit
600: Waste disposal unit
700: Wastewater treatment unit

Claims (10)

It is an oil removal device that removes oil from food waste using a three-phase centrifuge.
A preprocessing unit that preprocesses food waste;
An oil removal unit 200 installed downstream of the pretreatment unit to separate and remove oil from food waste using a three-phase centrifuge;
An anaerobic digestion unit (400) installed downstream of the oil removal unit (200) to anaerobically digest food waste;
A biogas purification unit 500 installed on one side downstream of the anaerobic digestion unit 400 to purify the biogas discharged from the anaerobic digestion unit 400;
A waste treatment unit 600 installed downstream of the anaerobic digestion unit 400 to process waste discharged from the anaerobic digestion unit 400; and
An oil removal device using a three-phase centrifugal separator, comprising: a wastewater treatment unit (700) installed downstream of the waste treatment unit (600) to treat wastewater discharged from the waste treatment unit (600). According to claim 1,
The preprocessor,
A first preprocessing unit 100 that primarily preprocesses the brought in food waste; and
An oil removal device using a three-phase centrifugal separator, comprising a second pretreatment unit (300) installed downstream of the oil removal unit (200) to secondarily preprocess food waste. According to claim 2,
The first preprocessing unit 100,
A food input hopper that stores the brought in food waste, has a double screw installed at the bottom to transport the food waste, and has perforated nets of a predetermined particle size installed at predetermined intervals;
A crusher sorter installed downstream of the food input hopper to separate coarse foreign substances from the stored food waste through crushing and primary crushing;
A secondary shredder installed downstream of the shredder and sorter to maintain the particle size below a predetermined level and select foreign substances through secondary shredding of the primary shredded and sorted food waste; and
A screw press installed downstream of the secondary shredder to produce separable food waste water by separating the shredded and sorted food waste into dehydrated food cake and food waste water through dehydration. A three-phase centrifugal separator comprising a. Oil removal device used. According to claim 2,
The second preprocessing unit 300,
A food cake mixer that evenly mixes the food dehydration cake separated in the screw press of the first pretreatment unit 100 and the dehydration liquid in the desorption liquid tank of the three-phase centrifuge of the oil removal unit 200 before inputting it into the food TS control tank. ;
A food TS control tank installed downstream of the food cake mixer and adjusting TS (Total Solid) to 10% through time constant hydration;
A fine shredder installed downstream of the food TS control tank to crush the food waste shredded to a particle size of 10 mm or less in the first pre-processing unit 100 to a particle size of 3 mm or less;
A fine sorter installed downstream of the fine shredder to select and remove vinyl and fibrous foreign substances larger than 3 mm from food particles crushed to 3 mm or less and maintain a foreign material removal rate of 96% or more;
A cyclone installed downstream of the fine separator to remove fine inorganic substances (FS, Fixed Solid) such as sediment, crushed eggshells, and crushed shellfish to maintain a removal rate of foreign substances in the substrate at more than 97%;
An intermediate storage tank installed downstream of the cyclone, where more than 97% of foreign substances contained in the food waste are removed and the particle size is uniformly pretreated to 3 mm or less, and then temporarily stored before being introduced into the anaerobic digestion unit 400. An oil removal device using a three-phase centrifuge, characterized in that. According to claim 1,
The oil removal unit 200,
A low-speed solid-liquid separator that separates coarse foreign substances of 4 mm or more contained in the food waste water from the food waste water separated in the pretreatment unit;
A three-phase centrifuge installed downstream of the low-speed solid-liquid separator to remove more than 80% of the oil by centrifuging the three phases of solid, liquid, and oil using centrifugal force;
A three-phase centrifugal separator tank installed on one side downstream of the three-phase centrifugal separator to store solid matter and liquid desorbed liquid separated from the three-phase centrifuge and maintain a uniform concentration through a vertical shaft stirrer;
An oil tank installed on the other side downstream of the three-phase centrifugal separator to temporarily store the oil separated from the three-phase centrifugal separator;
An oil purification tank installed downstream of the oil tank to remove foreign substances such as moisture in the recovered oil by heating the recovered oil with a heating coil built into the oil tank; and
An oil storage tank with a built-in heating coil installed downstream of the oil purification tank to temporarily store the oil produced in the oil purification tank. An oil removal device using a three-phase centrifugal separator, comprising: According to claim 5,
The three-phase centrifugal separator is an oil removal device using a three-phase centrifuge, characterized in that it is provided with screw blades and an oil-water separation plate. According to claim 1,
The anaerobic digestion unit 400 is an oil removal device using a three-phase centrifuge, characterized in that it consists of a two-phase anaerobic digestion system in which the acid fermentation tank and the anaerobic digestion tank are separated. According to claim 1,
The biogas purification unit 500,
A primary desulfurization facility that first removes high concentration hydrogen sulfide contained in biogas by injecting FeCl ₃ into the anaerobic digestion tank of the anaerobic digestion unit 400;
A water separator that first removes moisture in biogas using a swirling flow method;
A biogas dehumidifier installed downstream of the water separator to secondarily remove moisture by cooling the primarily removed moisture;
A gas filter installed downstream of the biogas dehumidifier to thirdly remove fine dust and mist-like moisture in the biogas using a filter;
A dry desulfurization facility installed downstream of the gas filter to secondarily remove hydrogen sulfide in the biogas first removed in the anaerobic digestion tank;
A siloxane removal facility installed downstream of the dry desulfurization facility to remove siloxane in biogas using the adsorption function of activated carbon;
A gas storage tank installed downstream of the siloxane removal facility to temporarily store biogas from which moisture, hydrogen sulfide, and siloxane have been removed;
It is installed downstream of the gas storage tank and uses a membrane to separate CO ₂ from the biogas temporarily stored in the gas storage tank through the difference in permeation rates between CH ₄ and CO ₂ and produce biomethane containing more than 98% of CH ₄ Membrane equipment that produces; and
A three-phase centrifuge comprising a steam reforming facility installed at the rear of the membrane facility to produce more than 99% H ₂ through a steam reforming reaction from biomethane from which CO ₂ has been separated and removed. Oil removal device using. According to claim 1,
The waste disposal unit 600,
A digestion filtrate storage tank that temporarily stores the digestion filtrate generated in the anaerobic digestion unit 400;
A centrifugal dehydrator installed downstream of the digestion filtrate storage tank to separate solid and liquid from the stored digestion filtrate;
A dehydrated cake storage tank for temporarily storing the solid dehydrated cake separated from the centrifugal dehydrator;
A sludge drying facility for producing a dehydrated cake with a moisture content of 80% temporarily stored in the dehydration cake storage tank into a dried product with a moisture content of 10% or less by a heat source of biogas. An oil removal device using a three-phase centrifuge, characterized in that it includes a sludge drying facility. According to claim 1,
The wastewater treatment unit 700,
a desorption liquid storage tank that stores the liquid separated from the centrifugal dehydrator of the waste disposal unit 600;
A rapid mixing tank installed via a transfer pump downstream of the desorption liquid storage tank and reacting fine sludge with chemicals by adding polymer (PAC) and NaOH;
A slow mixing tank that forms sludge floc by slow agitation using chemicals introduced in the rapid mixing tank;
A pressurized flotation tank that levitates the floc formed in the slow mixing tank by injecting fine air and removes suspended solids by a flotation sludge removal facility at the top;
A pre-treatment treatment tank installed at the rear of the pressurized flotation tank to first remove organic substances and suspended solids in the wastewater and then adjust and equalize the flow rate before inputting it into the subsequent nitrogen and phosphorus removal process;
A denitrifying tank installed at the rear end of the pre-treatment tank to remove nitrogen by transporting it by a transfer pump, supply an external carbon source, and install a submersible mixer to increase nitrogen removal efficiency through stirring;
an aeration tank installed downstream of the denitrification tank to change ammonia nitrogen into nitrate nitrogen via nitrite nitrogen;
MBR (Membrane Bio Reactor) installed downstream of the aeration tank to further remove organic matter, suspended solids, TN (total nitrogen), and TP (total phosphorus) contained in the wastewater;
A linked treatment tank installed downstream of the MBR to link and treat treated water treated to a final TN (total nitrogen) of 250 mg/L or less and TP (total phosphorus) of 30 mg/L or less to a sewage treatment plant; and
An oil removal device using a three-phase centrifugal separator, comprising: a wastewater sludge storage tank installed downstream of the pressure flotation tank to treat flotation sludge generated in the pressure flotation tank.

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