KR20100030211A - Apparatus for solubilization pretreatment of organic sludge and method therefor - Google Patents

Abstract

PURPOSE: An apparatus for solubilizing organic sludge and a method thereof are provided to solubilize the organic sludge while minimizing an energy loss through proper heat and pressure, to reduce a size of a digestion tank by relatively increasing a digestion efficiency and reducing a residence time through an anaerobic digestion, and to minimize a discharge of the sludge by improving dehydration of the sludge. CONSTITUTION: An apparatus(100) for solubilizing organic sludge comprises: a heat pressurization reactor(104) which heat-treats the organic sludge; a heating unit(103) which heats the heat pressurization reactor at a reaction temperature carbonizing the organic sludge; a measuring units(102,108) which senses a temperature and pressure of inner part of the heat pressurization reactor; and a control unit which controls the temperature of the heat pressurization reactor detected by the measuring unit and makes the pressure be larger than a saturation vapor pressure. The reaction temperature of the heat pressurization reactor is 100~300°C and an adjusting pressure is 101.3 ~ 8815.3KPa. Saturated steam of the heat pressurization reactor is discharged through a steam vent(105) to the outside when the pressure becomes over the adjusting pressure of the heat pressurization reactor.

Description

Apparatus for solubilization pretreatment of organic sludge and method therefor}

The present invention relates to an apparatus and method for solubilizing organic sludge, and more particularly, to organic sludge, such as lignin sludge generated in a pulp production process, dewatered sludge generated in a sewage treatment plant, and wastewater sludge generated in a plant wastewater treatment plant. Through the heating and pressing reaction, it destroys the cell membrane or cell wall of the microorganisms that make up most of the sludge, releasing available organic substances, thereby improving the anaerobic digestion efficiency of digestive tanks, reducing the residence time, and improving the methane production to save energy. The present invention relates to an apparatus and method for solubilizing organic sludge which can reduce the amount of dewatered sludge discharged through reduction and improvement of dewatering capacity.

As is well known, the amount of organic sludge is continuously increasing and its treatment is a big environmental problem, and landfill and ocean dumping, which are representative treatment methods, are blocked through various regulations.

As a result, incineration, pyrolysis and other recycling methods exist, but there is an appropriate moisture content to apply each method, and a drying process that consumes high energy is necessary as a pretreatment technology. Therefore, it is urgent to develop a new treatment method that is environmentally friendly and capable of large-scale treatment.

Anaerobic digestion process is a process for stabilization of sludge. The organic material is decomposed by anaerobic microorganisms in the absence of oxygen, and methane gas is generated to recover energy, and the sludge dehydration efficiency is improved to generate final sludge. The effect of weight reduction can be obtained.

This useful anaerobic digestion process requires a long time of 20 days or more as a digestive method that requires a long time. The capacity of the reactor must be large, and the efficiency of anaerobic digestion is only about 30%, and the operating conditions are aerobic. The problem is that it is more difficult than the microbial process.

Accordingly, pretreatment is necessary to simultaneously achieve an increase in the efficiency of anaerobic digestion and reduction of the final discharge sludge.

The anaerobic digestion process is divided into a hydrolysis step of liquefying (solubilizing) solid organic matter and a step of producing methane using liquefied organic matter. The rate-limiting step of the entire anaerobic digestion process is known as the liquefaction of solid organic matter.

Therefore, various pretreatment methods have been actively conducted to research how to break down the cell wall and release available organic substances to artificially reduce the hydrolysis step to reduce the overall reaction time and maximize the digestion efficiency.

Pretreatment methods include mechanical methods such as crushing, wet milling, JET spraying, chemical methods using acid and base, heat treatment, freezing / thawing, ozone, and enzyme treatment. Problems have not yet been applied to large scale commercialization processes.

Therefore, the present invention has been proposed to overcome the limitations of the prior art as described above, and an object of the present invention is to apply a dehydration sludge to a heating pressurization reaction in an oxygen-free reducing atmosphere without drying, so that the existing anaerobic digestion treatment equipment is solubilized. System and method for solubilizing organic sludge that can reduce the residence time and digester capacity and increase the production of methane gas by improving the digestion efficiency of anaerobic digester that can recover energy such as methane gas as well as stabilization and reduction of organic sludge in To provide.

Another object of the present invention is to provide an apparatus and method for solubilizing organic sludge which can improve the dewatering of sludge to minimize the discharge of the final sludge.

It is another object of the present invention to provide an apparatus and method for solubilizing organic sludge by applying a heating and pressing reaction to save energy by minimizing energy consumed by vaporized energy of moisture than a heating and pressing reaction.

According to one aspect of the present invention for achieving the above object, an organic sludge solubilizing device, comprising: a heated and pressurized reactor for receiving and heat treating the organic sludge; Heating means for heating the heated pressurized reactor to a reaction temperature for carbonizing the organic sludge; Measuring means for sensing a temperature and a pressure inside the heated pressurization reactor; And control means for controlling the temperature and pressure of the heated pressurization reactor sensed by the measuring means to be equal to or higher than the saturated steam pressure.

The reaction temperature of the heated pressurized reactor is adjusted to 100 ~ 300 ℃ and the pressure is controlled from 101.3 to 8815.3KPa for 20 minutes to 3 hours.If the pressure exceeds the control pressure, the saturated steam inside the heated pressurized reactor is discharged to the outside through the steam vent. It is preferable.

The heating pressurization reactor uses a closed type reactor having excellent airtightness for pressurization.

According to another aspect of the present invention, there is provided a solubilization method using the above-described solubilization apparatus for organic sludge, comprising: introducing the organic sludge into a closed heating pressurization reactor; Including the step of heating the introduced organic sludge to the reaction temperature, the reaction temperature of the heating and pressure reactor is 100 ~ 300 ℃, the pressure is 101.3 ~ 8815.3KPa 20 minutes to 3 hours of operation, and the temperature of the heating and pressure reactor Adjust the pressure to be above the saturated steam pressure.

According to the present invention, the main effect is that the organic sludge can be solubilized while minimizing energy loss through proper heating and pressurization.

In addition, the solubilized sludge produced can reduce the size of the digester by increasing the digestion efficiency and reducing the residence time relatively through subsequent anaerobic digestion.

In addition, it is possible to obtain high concentration of methane gas as a by-product by increasing the amount of gas generated, and to improve sludge dehydration to minimize sludge discharge and stabilize the sludge generated in the sewage treatment process.

The generated methane gas can be used as a heat source for heating the pressurized pressurization reaction or as a heat source maintaining the reaction temperature of the anaerobic digestion tank, and has the effect of preventing the occurrence of odor by a closed reactor.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. In the drawings, like reference numerals designate like elements and detailed descriptions thereof are omitted.

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

1 is a schematic view showing the configuration of an apparatus for solubilizing organic sludge according to the present invention.

As shown in FIG. 1, an apparatus for solubilizing organic sludge 100 according to the present invention is a device for providing a solubilization method through heating and pressing for organic sludge, and includes a reaction part, a controller, and a condensation part. The reaction section in which the pressurization reaction is carried out is a heating pressurization reactor 104 for solubilization, a heater 103 as a heating means for heating the reactor 104, and a pressure gauge as a measuring means for sensing the temperature and pressure inside the reactor 104 ( 102 and a temperature sensor 108 and its peripheral devices, which include an agitator 101, a steam vent 105, a temperature control means 106, a saturated water outlet valve 107, Etc. Of course, it includes a power source 109 for supplying electrical energy to each component.

Although not shown on the other hand, the control unit is a computer that can control the operation of the control panel (control panel) and the solubilizer and store the real-time reaction conditions using the values measured by the temperature sensor 108 and the pressure gauge 102 Condensation unit is made of a heat exchanger for cooling the high temperature water vapor discharged during the pressure control.

The stirrer 101 is for stirring the sludge contained in the reactor 104, the pressure gauge 102 is for measuring the internal pressure of the reactor (104). The heater 103 is for heating the reactor 104, and an electric heating furnace is preferable.

Temperature control means 106 is to control the operation of the heater 103 to adjust the internal temperature of the reactor 106, the temperature range is adjusted to 100 ~ 300 ℃ the temperature required for carbonization of organic matter.

The saturated water outlet valve 107 is for discharging the saturated and condensed water separated from the sludge to the outside of the reactor 104, the temperature sensor 108 measures the internal temperature of the reactor 104 to measure The value is provided to the thermostat 106.

The steam vent 105 is for allowing the saturated steam inside the reactor 104 to be discharged to the outside when the internal pressure of the reactor 104 is greater than or equal to a certain level. The pressure at which the steam vent 105 is opened is determined by the present invention. According to the operating method of the solubilizer of the organic sludge according to the operation can be variously determined, the range is 101.3 ~ 8815.3KPa is operated at a pressure slightly higher than the saturated steam pressure corresponding to the operating temperature.

Of course, the steam vent 105 may be used only to discharge the steam inside the reactor 104 after the work is completed.

2 is a view showing a modification of the device of Figure 1, Figure 3 is a block diagram showing the configuration of peripheral devices for adjusting the temperature and pressure inside the reactor.

As can be seen in FIGS. 2 and 3, in some cases, the pressure information measured by the pressure gauge 102 is further provided to the temperature / pressure adjusting means 106a, and the temperature / pressure adjusting means 106a is the pressure gauge 102. Based on the pressure information inside the reactor 104 and the internal temperature information by the temperature sensor 108, the operation of the heater 103 or the operation of the heater 103 and the steam vent 105 is automatically controlled. do. This control function can be easily implemented in a program by those skilled in the art with reference to the contents of the present invention. The rest is the same as described in the embodiment of FIG.

Referring to the operation of the organic sludge solubilizing device of the present invention configured as described above are as follows.

When the organic sludge is introduced into the heating pressurization reactor 140 and the heater 103 is operated to heat the injected sewage sludge to a reaction temperature of 100 to 300 ° C., the sludge itself is automatically heated due to the evaporation of water and low molecular weight organic matter. The pressure is controlled to be slightly higher than the saturated steam pressure (101.3 ~ 8815.3 KPa) for the reaction temperature. The reaction time is 20 minutes to 3 hours.

In this heating step, the water contained in the sludge consumes only minimal vaporization energy to reach the reaction temperature. Therefore, the water of the sludge does not change into water vapor even at a reaction temperature of 100 ℃ or more, so that the energy consumption can be reduced to a minimum compared to the existing heat treatment process.

At this time, the high temperature water (hot water) acts as a heat medium in the sludge itself to further accelerate the destruction of the sludge cell wall. Therefore, the floc of the sludge is dismantled by the pressure due to the heat energy and saturated steam pressure obtained through warming, the cell wall is destroyed, the microorganism of the sludge is decomposed and solubilized as the cell solution is eluted.

In addition, in the process of solubilizing the sludge through the heating and pressing reaction, the viscosity of the sludge sample itself decreases when the reaction temperature is increased, thereby improving the dehydration property.

In addition, the heated and pressurized reactor of the present invention uses an airtight reactor having excellent airtightness for pressurization, and under the reaction conditions of suppressing evaporation of water, the effect of suppressing odor is excellent.

In addition, due to the increase in the SCOD of the solubilized sludge produced by the use of anaerobic microorganisms, the digestion time is shortened and the digestion efficiency is improved to increase the amount of biogas generated.

On the other hand, if the results of the conventional pretreatment methods for solubilization are found in the literature, the heat treatment method similar to the heating pressure of the present invention increases the SCOD from 1800 mg / L to 13760 mg / L when heat treated at 170 ° C., about 7.6 times higher. The anaerobic digestion efficiency and gas generation rate were also improved.

In the case of mechanical pretreatment, the SCOD increased by 80%. In the case of ultrasonic treatment, the SCOD increased up to 3.8 times as the treatment time increased.

Reaction temperature SCOD (mg / L) Concentrated Sludge 525 Dewatering Sludge 8,270 150 ℃ 44,488 170 ℃ 62,444 200 ℃ 78,510 250 ℃ 67,444

Table 1 shows the SCOD results of the product after the reaction with the sludge sample applied in the above manner (warm pressurization). As can be seen from Table 1, it can be seen that the increase of the SCOD reliably appeared depending on the reaction temperature of the heating and pressing reaction.

In particular, it is possible to confirm the increase of SCOD up to 100 times compared to the injected sludge sample. Therefore, it can be confirmed that solubilization is better than the conventional pretreatment method.

In addition, it can be seen that the higher the reaction temperature does not increase the SCOD but the optimum reaction temperature.

Generally, SCOD / TCOD values are used to indicate solubilization rate. Looking at Figure 4 it can be seen that the SCOD / TCOD ratio increases as the heating reaction reaction temperature increases compared to the concentrated sludge as a control. This is because organic matter in the form of solids was destroyed, decomposed and eluted through a heating and pressing reaction. Therefore, it can be seen that solubilization is well performed through the heating and pressing reaction.

Figure 5 shows the particle size analysis results of solubilized sludge after the granularity and warming pressure reaction of the concentrated material sludge (water content of 97% level) and dehydrated sludge (water content of 80%).

As can be seen from Figure 5, it can be seen that as the reaction temperature increases as a whole, the particle size of the solid becomes smaller.

In particular, it can be seen that the coarse particles rapidly decrease in size and increase in medium sized particles and fine particles. This means that the sludge's microbial flocs are disassembled and the cell walls are destroyed through the warming and pressurization to reduce the overall particle size. Therefore, it can be said that indirect evidence of solubilization because cell fluid is eluted through the destruction of these solids.

FIG. 6 is a diagram showing that the sludge sample is improved in dehydration through a pressurized pressurization reaction. A representative indicator for evaluating sludge dewatering capacity is CST (Capillary Suction Time) and TTF (Time to filter). The results of the measurement of protein known as a representative ECP (Extra Cellular Polymers) substance that causes viscosity and indirect effects on the plot are shown.

As can be seen from the chart, when the heated and pressurized reaction temperature is lower than 170 ° C., as in the conventional pretreatment method, as the protein concentration increases, the viscosity increases and dehydration deteriorates.

However, it can be seen that as the reaction temperature increases, dehydration also improves with a sharp decrease in viscosity. Therefore, all these evidences indicate that solubilization of sewage sludge is achieved through warming pressurization, and the solubilization rate is higher than that of the conventional method. Therefore, it is expected that the subsequent anaerobic digestion process will reduce the residence time and increase the gas generation.

What has been described above is just one preferred embodiment of the apparatus and method for heating pressurizing solubilization for improving the anaerobic digestion efficiency of organic sludge according to the present invention, the present invention is not limited to the above-described embodiment, the following claims As claimed in the scope of the present invention, those skilled in the art to which the present invention pertains will have the technical spirit of the present invention to the extent that various modifications can be made.

1 is a schematic view showing the configuration of an apparatus for solubilizing organic sludge according to an embodiment of the present invention,

FIG. 2 is a schematic view showing the configuration of an apparatus for solubilizing organic sludge according to a modification of the apparatus of FIG. 1,

Figure 3 is a block diagram showing the configuration of peripheral devices for adjusting the temperature and pressure inside the reactor.

<Description of the symbols for the main parts of the drawings>

101: stirrer 102: pressure gauge

103: heater 104: heating pressure reactor (Autoclave)

105: water vapor vent 106: temperature control means

106a: temperature / pressure control means 107: valve

108: temperature sensor

Claims (5)

In the solubilization device of organic sludge, A heated and pressurized reactor in which the organic sludge is received and heat treated; Heating means for heating the heated pressurized reactor to a reaction temperature for carbonizing the organic sludge; Measuring means for sensing a temperature and a pressure inside the heated pressurization reactor; And control means for controlling the temperature and pressure of the heated pressurized reactor sensed by the measuring means to be equal to or higher than the saturated steam pressure. Solubilizer of organic sludge. The method of claim 1, The reaction temperature of the heated and pressurized reactor is 100 ~ 300 ℃, the pressure is adjusted to 101.3 ~ 8815.3KPa 20 minutes ~ 3 hours of operation Solubilizer of organic sludge. The method of claim 2, When the controlled pressure of the warming pressure reactor is higher than the discharge of the saturated steam in the warming pressure reactor to the outside through the steam vent Solubilizer of organic sludge. The method of claim 1, The heated and pressurized reactor uses an airtight reactor having excellent airtightness for pressurization. Heating pressurization solubilizer for organic sludge In the solubilization method using the solubilizing apparatus for organic sludge according to claim 1, Injecting the organic sludge into a closed heating pressurization reactor; Including the step of heating the introduced organic sludge to the reaction temperature, The reaction temperature of the heated pressurized reactor is 100 ~ 300 ℃, the pressure is 101.3 ~ 8815.3KPa 20 minutes to 3 hours of operation, to control the temperature and pressure of the heated pressurized reactor to be above the saturated steam pressure Solubilization method of organic sludge.

Images