KR20230001329A - Treatment process of fluid mixture - Google Patents

Abstract

The present invention relates to a process for treating a fluid mixture, including the steps of: introducing the fluid mixture into a pyrolysis device; drying the fluid mixture in the pyrolysis device; and pyrolyzing the fluid mixture in a hypoxic or anoxic atmosphere at a temperature of 350 to 500 deg. C within the pyrolysis device.

Description

TREATMENT PROCESS OF FLUID MIXTURE}

The present invention relates to a process for treating a fluidized mixture, and more particularly, to a process for minimizing the amount of harmful compounds discharged during the treatment of a fluidized mixture.

BACKGROUND OF THE INVENTION [0002] Various types of products are being developed and produced as the modern society becomes more sophisticated. In the production process of a product, such as a chemical process, a large amount of industrial waste is generated as well as the product. In addition, products produced and sold are also recovered as waste after the end of their lifespan. Therefore, in modern society where numerous products are produced and discarded, the amount of waste generated every year is considerable, and waste often contains compounds harmful to the human body. Accordingly, it is desirable to appropriately treat and discharge waste containing harmful compounds.

Methods widely known as waste treatment methods include incineration, landfill, plasma treatment, high-temperature base reaction, and subcritical water treatment.

In the case of incineration, it is a generally preferred method in that the volume of waste can be significantly lowered and some of the energy used can be recovered. Harmful compounds vaporize and are released into the atmosphere, contaminating the atmosphere. In particular, incineration has a problem in that it does not easily meet the high standards as social demands for air environment protection have recently increased. In the case of landfill, it is a method widely used because of its simplicity, but because harmful compounds are thermochemically stable, they cannot be decomposed when landfilled, contaminate the soil, or dissolve in fat and accumulate in living organisms, causing adverse effects on the food chain. , there is a problem that it can eventually flow into the human body.

Plasma treatment, high-temperature base reaction, subcritical water treatment, etc. also have problems in that high concentrations of harmful compounds cannot be treated, the cost of facility operation is high, and decomposed harmful compounds are resynthesized. In addition, as a method of removing harmful compounds, there are methods using activated carbon adsorption, bag filter, scrubbing, etc. in the terminal process, but since harmful compounds are physically removed rather than decomposed, there is a large change in the total amount of harmful compounds. There is a problem that there is no, and the efficiency of removal is also low.

Therefore, there is a need for research on a treatment process that can chemically decompose harmful compounds to the maximum, suppress resynthesis of harmful compounds, and can be simply performed without requiring complicated facilities.

Korean Application Publication No. 10-2011-0129845 Korean Application Publication No. 10-2014-0039647

The present invention is to solve the problems of the prior art, and can completely decompose harmful compounds, suppress the re-synthesis of harmful compounds, and reduce control points and minimize dust by simplifying process steps. It is intended to provide a process for treating the mixture.

One embodiment of the present invention

Injecting the fluid mixture into a pyrolysis device;

a drying step of drying the fluid mixture in the pyrolysis unit; and

A thermal decomposition step of thermally decomposing the fluidized mixture in a low oxygen or anoxic atmosphere and at a temperature of 350° C. to 500° C. in the thermal decomposition device.

It provides a process for treating a fluid mixture comprising a.

In another embodiment of the present invention, the process further includes a combustion step of burning the gas generated in the pyrolysis step.

In another embodiment of the present invention, the process of treating the fluid mixture further includes a pulverization step of pulverizing the fluid mixture to form particles before or after the step of introducing the fluid mixture into a pyrolysis device.

In another embodiment of the present invention, the drying step is a step of drying the fluid mixture at 150 ° C. or more and 200 ° C. or less.

In another embodiment of the present invention, the drying step is a step of performing drying such that the moisture content of the fluid mixture is 50 wt% or less.

In another embodiment of the present invention, the fluid mixture of the above-described embodiments is a waste in the form of sludge.

In the treatment process of the fluid mixture of the present invention, the water content of the fluid mixture can be effectively controlled by drying the fluid mixture and then thermal decomposition, thereby increasing the drying energy efficiency in the thermal decomposition step, and the chlorine compounds and chlorine compounds in the fluid mixture The efficiency of the overall treatment process can be improved by enabling the same harmful compounds to be fully decomposed and maximizing the efficiency of thermal decomposition and combustion. In addition, in the process of treating the fluid mixture of the present invention, the installation of a separate dryer can be minimized by performing thermal decomposition after drying in a thermal decomposition device. As a result, it is possible to minimize the generation of dust that may occur during the movement of the fluid mixture after drying, to secure a working space due to not installing a dryer, and to reduce the number of management points by reducing the number of process steps, greatly improving the working environment. can do.

1 is a graph showing the change in moisture content according to the drying temperature in the drying step performed in Example.
Figure 2 is a graph showing the residual toxic concentration of waste solids after thermal decomposition according to the moisture content of the sample after drying.

Hereinafter, the present invention will be described in more detail.

The terms or words used in this specification and claims should not be construed as being limited to ordinary or dictionary meanings, and the inventors may appropriately define the concept of terms in order to explain their invention in the best way. It should be interpreted as a meaning and concept consistent with the technical idea of the present invention based on the principle that there is.

One embodiment of the present invention

Injecting the fluid mixture into a pyrolysis device;

a drying step of drying the fluid mixture in the pyrolysis unit; and

A thermal decomposition step of thermally decomposing the fluidized mixture in a low oxygen or anoxic atmosphere and at a temperature of 350° C. to 500° C. in the thermal decomposition device.

It provides a process for treating a fluid mixture comprising a.

In one embodiment of the present invention, the fluid mixture is waste obtained in the field of chemical processing, and may have a form of sludge in which solid particles and moisture generated during the process are mixed. Specifically, the waste to be treated in the present invention is a solid precipitate generated while treating wastewater and wastewater generated during the process of manufacturing ethylene dichloride, vinyl chloride monomer, etc. from ethylene It may contain. In addition, the waste contains harmful chlorine components such as polychlorinated biphenyl, polychlorinated dibenzo-p-dioxin, polychlorinated dibenzofuran, and chlorophenol. It may be included at a concentration of about 1,000 ppm to 20,000 ppm. Here, the concentration of harmful chlorine components means the concentration of all chlorine present in the fluidized mixture, which can be measured using ion chromatography (IC).

In particular, in the present invention, toxicity can be efficiently removed by passing through drying and pyrolysis steps in a pyrolysis device to be described later in the fluid mixture containing the harmful chlorine component at a high concentration. For example, the toxicity in general waste is less than 1,000 pg I-TEQ/g, most of which is less than 100 pg I-TEQ/g, and it is relatively easy to remove such low toxicity by various methods. On the other hand, highly toxic wastes, such as wastes of 30,000 pg I-TEQ/g or more, are not easily removed by general methods. For example, a treatable subject in the present invention may be waste with a toxic concentration of 30,000 pg I-TEQ/g or more, specifically 30,000 pg I-TEQ/g to 1,000,000 pg I-TEQ/g of the fluid mixture. In the present invention, toxicity can be efficiently removed from highly toxic waste through drying and pyrolysis steps in a pyrolysis device described below. In particular, in such a fluid mixture containing harmful chlorine components in high concentration, drying conditions and/or moisture content described later may affect efficiency in the thermal decomposition and combustion steps. According to embodiments of the present invention, the residual toxic concentration in the waste solid obtained after the pyrolysis step is 500 pg I-TEQ/g or less, preferably 200 pg I-TEQ/g or less, more preferably 150 pg I-TEQ /g or less.

In the present specification, the toxic concentration (pg I-TEQ / g) is the sum of the product of the concentration of 17 toxic congeners of PCDD (polychlorinated dibenzodioxin) and PCDF (polychlorinated dibenzofuran) and the toxicity factor (I-TEF) is a value derived from

<expression>

Toxic Concentration (I-TEQ) = Σ(PCDDi X I-TEFi) + Σ(PCDFi X I-TEFi)

In the above formula, PCDDi and PCDFi are the masses of dioxins having i chlorine, respectively, and I-TEFi means the toxicity equivalent conversion factor of dioxins having i chlorine.

In addition, the waste may include an organic material and an inorganic material in a weight ratio of 3:7 to 7:3, specifically 4:6 to 6:4, for example, 1:1.

Hereinafter, a treatment process according to embodiments of the present invention will be described step by step.

Preprocessing step (S1)

In one embodiment of the present invention, the process of treating the fluid mixture may further include a pulverization step of preparing a particle form by pulverizing the fluid mixture before or after the step of introducing the fluid mixture into a pyrolysis device.

When waste in the form of sludge is pulverized and produced in the form of particles, by controlling the particles of the waste to be relatively uniform, it is possible to minimize heat transfer to harmful compounds due to non-uniform particle sizes in the sludge. Specifically, based on the same mass, particle-type waste may have a larger surface area than sludge-type waste, and this large surface area becomes an element that facilitates heat transfer, thereby reducing the subsequent pyrolysis and combustion steps. Efficiency can be further increased.

As the method of pulverization, a general method known to be able to pulverize a material in the form of sludge may be used, and for example, it may be performed using a general pulverizer.

In one embodiment of the present invention, the process of treating the fluid mixture may further include dehydrating the fluid mixture.

Drying step (S2)

A process for treating a fluid mixture according to an exemplary embodiment of the present invention is characterized in that drying of the fluid mixture is performed in a pyrolysis device. Accordingly, the process of treating the fluid mixture includes introducing the fluid mixture into a pyrolysis device; and a drying step of drying the fluid mixture in the pyrolysis device.

According to the above embodiment, it is possible to effectively reduce the moisture content of the fluid mixture through the drying step, and at the same time, to perform drying in the pyrolysis device without a separate drying device, thereby preventing the occurrence of costs for maintenance and management of equipment, and hazardous materials. In processing, there is little risk of being exposed to risk factors during device optimization work.

According to one embodiment, after the drying step is performed in the pyrolysis device, a heating section may be designed in the pyrolysis device to perform the pyrolysis step described later. Accordingly, drying may be performed in a relatively low temperature section, and then thermal decomposition may be performed at a high temperature. For example, the heating section may gradually increase the temperature over time, have a heating section of two or more stages, or may have an isothermal section of two or more stages. In the two or more isothermal sections, the temperature of each isothermal section is maintained, but the temperature of the following isothermal section is maintained higher than that of the preceding isothermal section, and the temperature may be increased. The heating section and the isothermal section may be referred to as a heat source supply section for raising or maintaining a temperature.

According to another exemplary embodiment, in the pyrolysis device, the heat source supply section of two or more stages takes 10 hours or less.

According to one embodiment, in the drying step, the fluid mixture may be dried at 150 °C or more and 200 °C or less. By performing such a drying step, the fluid mixture such as sludge-state waste can be adjusted to a moisture content of a certain level, for example, 50 wt% or less. The fluid mixture whose moisture content is controlled in this way is applied to the subsequent pyrolysis step and combustion step. In the present specification, wt% representing moisture content can be calculated as the following formula as a * 100% calculated value of the value obtained by dividing the change in weight before and after drying by the value before drying.

Moisture content (wt%) = ((initial total weight) - (total weight after drying)) / initial total weight *100%

The initial moisture content before drying of highly toxic wastes obtained in the chemical process field is 99 wt%, including 99 wt% of water and 1 wt% of dry matter. Then, through a drying process, it may have a moisture content of 50 wt% or less. 50 wt% moisture content means a state containing 50 wt% moisture and 50 wt% dry matter, and 30 wt% moisture content means a state containing 30 wt% moisture and 70 wt% dry matter. The method of measuring the moisture content is not particularly limited, and a method in which an experimenter measures the change in weight before and after in a general drying device may be used, or a method using a moisture measuring device METTLER TOLEDO (HX204), moisture analyzer, or the like may be used. For example, it may be performed in the following manner.

- Set the zero point using a dish of the size recommended by METTLER TOLEDO (HX204), moisture analyzer.

- Put the sample to be analyzed into the dish.

- After a certain period of time, the measuring equipment indicates the moisture content of the sample.

By performing drying at the above temperature, it is possible to achieve a desired moisture content and at the same time minimize heat loss in the thermal decomposition step, thereby improving energy efficiency in the entire process. As a result of checking the change in moisture content according to the drying temperature, in the temperature range below 150 ℃, the minimum heat required for evaporation of the water contained inside the sludge may not be supplied, and in the temperature range above 200 ℃, it is relatively difficult to evaporate water. It can oversupply the heat required and negatively affect the final operating cost.

In addition, when the sludge is dried below a certain moisture content, the fluidity of the sludge itself is reduced, so that the overall sludge transport and thermal decomposition may not be performed smoothly. The lower the water content of the sludge, the lower the remaining harmful substances, but when the water content is below a certain level, the sludge does not move smoothly, which may cause problems in transport to the pyrolysis device.

According to one embodiment, the drying step is preferably performed within 24 hours. This is because long-term driving can reduce energy efficiency.

According to one embodiment, the drying step may be performed within 2 hours at 180 °C or more and 200 °C or less. Within the above temperature range, not only can the desired moisture content be achieved within 2 hours, but the change in moisture content is not large even when the time is maintained, so performing the drying step within 2 hours can greatly improve energy efficiency. there is. According to one example, the drying step may be performed at 180 °C or more and 200 °C or less for 1 hour or more and 2 hours or less.

According to one embodiment, the water content in the fluidized mixture after the drying step is preferably 10 wt% or more and 50 wt% or less, and more preferably 20 wt% or more and 40 wt% or less. Under the condition of less than 20wt%, fluidity is reduced due to low water content, and in excess of 40wt%, energy loss may occur due to evaporation in the thermal decomposition step due to residual moisture.

Control of the drying temperature and control of the moisture content described above may use a method known to those skilled in the art, and may be performed using a general device used for drying.

According to an exemplary embodiment, the fluid mixture after the drying step may have an angle of repose in a range of 21 degrees to 26 degrees when considering fluidity in a thermal decomposition step described later. As a general angle of repose measurement method, after putting a certain amount (the same amount each time) of the fluid mixture into a variable-controlled circular frame that can be continuously reproduced by the experimenter, that is, the same experiment can be performed each time, move the circular frame in the vertical direction at a constant speed. It refers to the angle at which the degree of inclination from the bottom surface of the degree to which the fluid mixture inside the round frame naturally flows down in a conical shape after being lifted up.

The movement of the fluid mixture in the pyrolysis device may be influenced by its own physical properties and external forces, such as the configuration of the pyrolysis device, rotational speed, presence or absence of baffles, size of baffles, shape of baffles, etc., but most closely related to the pyrolysis device. is most affected by the rotation of Rotation of the pyrolysis device may have a value between 0.01 rpm and 3 rpm when the angle of repose of the fluid mixture ranges from 21 degrees to 26 degrees. The value may be meaningful under the condition that the total time from input to discharge of the pyrolysis device is 1 hour or more, preferably 2 hours or more, specifically 4 hours or more, and by adjusting the rotation value in the pyrolysis device. The pyrolysis time of the fluid mixture can be increased by increasing the delay time. The corresponding rotation rpm can be varied according to the appropriate speed reducer ratio, preferably a rotation value of 0.1 rpm or more and 2.5 rpm or less, more specifically, 0.2 rpm or more and 2.3 rpm or less, more specifically, 0.3 rpm or more and 2.28 rpm or less. has a value of

Pyrolysis step (S3)

According to an exemplary embodiment of the present invention, after the above-described drying step (S2), a thermal decomposition step (S3) of thermally decomposing the fluid mixture in a low-oxygen or anoxic atmosphere at a temperature of 350 ° C. to 500 ° C. in a thermal decomposition device. carry out

The pyrolysis step is performed under a hypoxic or anoxic atmosphere. In the present specification, an oxygen-free atmosphere means an atmosphere in which oxygen among gases constituting the atmosphere does not substantially exist. The thermal decomposition step is preferably carried out in an atmosphere in which the concentration of oxygen is 3 vol% or less, preferably 1 vol% or less, and may be performed in an atmosphere in which oxygen does not exist at all, that is, the oxygen concentration is 0 vol%.

When the thermal decomposition step is performed under a hypoxic or anoxic atmosphere, a dechlorination reaction in which C-Cl bonds of harmful chlorine compounds in the fluidized mixture are broken or self-decomposition of harmful chlorine compounds at a temperature of 350 ° C. to 500 ° C. and under hypoxic or anoxic conditions The reaction can occur smoothly. On the other hand, under the condition that oxygen is present in an amount exceeding 3 vol%, oxygen reacts with organic materials and harmful chlorine compounds in the fluidized mixture to form another harmful chlorine compound or resynthesis of decomposed harmful chlorine compounds may occur.

The hypoxic or anoxic atmosphere is not limited to a specific gas, and may be, for example, a nitrogen atmosphere, an inert atmosphere, or a vacuum atmosphere. The inert atmosphere may be an argon atmosphere or a helium atmosphere, but is not limited thereto. Among them, when a nitrogen atmosphere is applied to a low-oxygen or non-oxygen atmosphere, it is economical because relatively inexpensive nitrogen can be used, and there are advantages in that the atmosphere is easy to create.

The temperature condition of the thermal decomposition step may be 350 °C to 500 °C, preferably 350 °C to 450 °C. When the temperature of the thermal decomposition step is within the above-described range, the final harmful compound removal rate may be higher in terms of connection with the combustion step described later. In particular, when the temperature of the thermal decomposition step is lower than the above range, sufficient removal of harmful compounds may not occur, and when the temperature of the thermal decomposition step is higher than the above range, the removal efficiency of harmful chlorine compounds is hardly improved. Only the amount used may greatly increase, which may deteriorate the economics of the overall process.

The execution time of the thermal decomposition step may be 1 hour to 6 hours, preferably 2 hours to 6 hours, and more preferably 3 hours to 5 hours. If the thermal decomposition time is too short, the thermal decomposition of harmful compounds cannot be sufficiently performed, and if the thermal decomposition time is too long, the effect of increasing the removal rate of harmful compounds compared to the increase in energy consumption is insignificant.

Combustion stage (S4)

In the thermal decomposition step, harmful compounds in the fluid mixture are decomposed to form gases, and some of the formed gas components may still have harmful properties. Therefore, harmful compounds in a gaseous state can be additionally burned and removed. Hazardous compounds in the gaseous phase remaining through combustion in this step can be converted into harmless low-molecular compounds such as carbon dioxide or water.

In the combustion step, it is preferable to introduce air in addition to the gas generated in the above-described pyrolysis step.

According to one embodiment, the temperature in the combustion step may be 900 °C to 1,200 °C, preferably 1,000 °C to 1,200 °C. When the temperature in the combustion step is lower than the lower limit of the above range, the remaining gaseous hazardous compounds cannot be sufficiently oxidized, and when it is higher than the upper limit of the above range, the amount of energy used for combustion is excessive, which may deteriorate the economics of the overall treatment process. can

The time of the burning step may be 5 to 60 minutes, preferably 15 to 30 minutes. If the time of the combustion step is too short, sufficient oxidation cannot be performed, and if it is too long, the amount of energy used for combustion is excessive, as in the case of temperature, and thus the economic feasibility of the overall treatment process may be deteriorated.

Cooling stage (S5)

The process of treating the fluid mixture according to another embodiment of the present invention may further include a step ( S5 ) of cooling the combustion gas generated by combustion in the combustion step. Harmful compounds that are not completely decomposed and removed may remain even after the above-described pyrolysis step (S3) and combustion step (S4), and harmful compounds that are partially decomposed may be re-synthesized into harmful compounds thereafter. Therefore, in order to prevent such resynthesis, it is preferable to remove energy required for resynthesis by cooling the combustion gas in which undecomposed harmful compounds may remain.

The cooling may be performed through a generally used method, for example, a method using cooling water, and rapid cooling is preferable to minimize resynthesis.

Post-processing step (S6)

The process of treating the fluid mixture according to one embodiment may further include a post-processing step (S6) for removing harmful gases and acidic gases in small amounts after the cooling step described above. For example, the process of treating the fluid mixture is a scrubbing step of passing the combustion gas cooled in the cooling step through a scrubber (S6-1) and/or a dust collecting step of passing the combustion gas cooled in the cooling step through a dust collector (S6-1). 2) may be further included. The scrubbing step (S6-1) and the dust collecting step (S6-2) may include either one or both.

Most of the harmful compounds can be removed through the post-treatment step.

The scrubber used in the scrubbing step (S6-1) may include at least one of an organic solvent scrubber for removing organic gas and a base solution scrubber for removing acid gas. The combustion gas may pass through an organic solvent scrubber and then a base solution scrubber. A toluene scrubber may be used as the organic solvent scrubber, and a sodium hydroxide scrubber may be used as the base solution scrubber. When using the above scrubber, the effect of removing harmful compounds can be maximized.

The dust collector used in the dust collection step (S6-2) may include a bag filter or the like.

In the post-processing step, when both the scrubbing step (S6-1) and the dust collecting step (S6-2) are included, the order is not particularly limited, and after passing the cooled combustion gas through the dust collector, the scrubber Alternatively, the cooled combustion gas can be passed through a scrubber and then through a dust collector. From the viewpoint of removing harmful gases, it may be more preferable to first pass through a dust collector among scrubbers and dust collectors.

Hereinafter, examples and experimental examples will be described in more detail to specifically describe the present invention, but the present invention is not limited by these examples and experimental examples. Embodiments according to the present invention may be modified in many different forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

Example 1

Waste sample in the form of sludge containing hazardous compounds (moisture content before drying 55 wt%, total concentration of PCDD and PCDF based on toxic equivalent equivalent concentration (pg I-TEQ/g) is 96354 pg I-TEQ/g) 50 g to 3 cm applied thinly. The waste sample in the form of sludge was put into a pyrolysis device, maintained at 180 ° C. for 2 hours, then heated to 400 ° C. for 1 hour to reach the target temperature of 400 ° C., and then heated for 2 hours to perform thermal decomposition. A nitrogen atmosphere was maintained during pyrolysis. The change in the function of the sample according to the temperature increase was confirmed, and the results are shown in FIG. 1 .

In order to minimize external factors during heating, physical movement was minimized and only the change in the value of self-evaporation in the sludge was confirmed without separate exhaust and intake. When a separate exhaust is installed, it is difficult to control the variable of the function change according to the state of the inlet and outlet air volume and wind speed. Therefore, the drying experiment is calculated based on the amount of function released from the sludge due to temperature heating under closed system conditions to control variables. Ultimately, it means the moisture content based on the equilibrium state with the surroundings in the closed system of the sludge.

According to FIG. 1, it can be confirmed that the decrease in the moisture content of the sludge decreases as a certain time passes at a certain temperature. It can be seen that sludge having a water content of 20 wt% or more and 30 wt% or less is formed after about 1 hour at 180° C. in the drying temperature setting section in the pyrolysis device of FIG. In the case of existing facilities, the fluidity of sludge particles in the pyrolysis machine and efficient energy operation have been hindered as the operation is performed without a separate heating section.

In the case of introducing a certain level of drying conditions in the pyrolysis device for proper distribution and supply of energy, more economical pyrolysis can be performed.

Examples 2 and 3

Except for performing the temperature and time in the drying step as shown in Table 1, the same procedure as in Example 1 was performed, and the moisture content (wt%) according to time is shown in Table 1.

dry
Temperature 15min 30min 60min 120min 240min 480min Example 2 150℃ 57.93 52.30 45.43 43.30 40.11 39.55 Example 3 200℃ 42.80 38.51 24.52 21.88 18.20 15.34

In the case of Example 2, 16 hours or more is required at 150 ° C., and energy costs may increase during operation of the pyrolysis machine due to residual moisture that does not evaporate when operated for 16 hours or less at the temperature of 150 ° C.

Example 3 can confirm the drying conditions of the sludge converging to 30% moisture content when operated within 1 hour at 200 ° C.

Considering the energy cost according to the isothermal maintenance and operation time, it can be seen that the thermal decomposition drying condition for 1 hour or more is preferable under the temperature condition of 180 ° C. or more and 200 ° C. or less.

reference example

In order to confirm the residual toxic concentration in waste solids due to thermal decomposition after drying in the above-described examples, a reference experiment was conducted. A sample having the same toxic concentration as that used in Example 1 was dried in the drying step until the moisture content in Table 2 below was reached, and the temperature was raised to 400 °C at a heating rate of 6.7 °C/min, followed by thermal decomposition for 2 hours (drying After sample weight 10 g, under nitrogen atmosphere). Residual toxic concentrations of waste solids after thermal decomposition are shown in Table 2 and FIG. 2 below.

Moisture content (wt%) waste solid residue
toxic concentration
(pg I-TEQ/g) waste solids
Residual mass (g) of exhaust gas
toxic concentration
(pg I-TEQ/g) Reference example 1 54.72 534.77 3.56 89,335.1 Reference example 2 31.54 530.56 5.24 63,876.3 Reference example 3 18.47 437.07 6.47 73,167.4 Reference example 4 8.17 119.43 7.24 78,261.1 Reference Example 5 3 183.05 7.26 51,437.2

Compared to Example 1, Reference Example 1 is the same as that in which thermal decomposition was performed without performing a drying step. Reference Examples 2 to 5 show the results of thermal decomposition after the moisture content is reduced by the drying step. It can be seen from Reference Examples 1 to 5 that controlling the water content of the fluid mixture through the drying step in the pyrolysis device affects the residual toxic concentration of the waste solid. According to Table 2, the residual toxic concentration of waste solids was shown to be the lowest in Reference Example 5 having the lowest moisture content, but considering the fluidity of the fluid mixture for fairness, the moisture content is preferably 10 wt% to 50 wt%. In this embodiment, the pyrolysis step has been performed, but the residual toxic concentration can be further reduced when the exhaust gas generated in the pyrolysis step is additionally burned through the combustion step.

Claims (17)

Injecting the fluid mixture into a pyrolysis unit;
a drying step of drying the fluid mixture in the pyrolysis unit; and
A thermal decomposition step of thermally decomposing the fluidized mixture in a low oxygen or anoxic atmosphere and at a temperature of 350° C. to 500° C. in the thermal decomposition device.
A process for treating a fluid mixture comprising a. The process of treating a fluid mixture according to claim 1, further comprising a combustion step of burning the gas generated in the pyrolysis step. The process of treating the fluid mixture of claim 1 , wherein the process of treating the fluid mixture further comprises a step of pulverizing the fluid mixture to form particles before or after the step of introducing the fluid mixture into a pyrolysis device. . The process of treating a fluid mixture according to claim 1, wherein the drying step is to dry the fluid mixture at 150 °C or more and 200 °C or less. The process of claim 1, wherein the drying step is performed so that the water content of the fluid mixture is 50 wt% or less. The process of claim 1, wherein the drying step is performed so that the moisture content of the fluid mixture is 20wt% to 40wt% or less. 7. The process according to any one of claims 1 to 6, wherein the drying step is carried out within 24 hours. The process for treating a fluid mixture according to any one of claims 1 to 6, wherein the drying step is a step of drying the fluid mixture at 180 °C or more and 200 °C or less. The process of treating a fluid mixture according to any one of claims 1 to 6, wherein the drying step is a step of drying the fluid mixture at 180 ° C. or more and 200 ° C. or less within 2 hours. The process for treating a fluid mixture according to any one of claims 1 to 6, wherein the thermal decomposition step is performed in an atmosphere in which the concentration of oxygen is 3 vol% or less. The process for treating a fluid mixture according to any one of claims 1 to 6, wherein the pyrolysis step is performed for 1 hour to 6 hours. The process of claim 2, wherein the burning step is performed at a temperature of 900° C. to 1,200° C. 3. The process of treating a fluid mixture according to claim 2, wherein the process of treating a fluid mixture further comprises a step of cooling the gas burnt in the combustion step. The method according to claim 13, wherein the process of treating the fluid mixture further comprises at least one of a scrubbing step of passing the combustion gas cooled in the cooling step through a scrubber and a dust collecting step of passing the combustion gas cooled in the cooling step through a dust collector. A process for processing a fluid mixture to be treated. The process of claim 1, wherein the pyrolysis device has two or more heating sections. The process of claim 1, wherein the pyrolysis device has two or more isothermal sections. The process according to any one of claims 1 to 6, wherein the residual toxic concentration in the waste solids obtained after the pyrolysis step is less than or equal to 500 pg I-TEQ/g.

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