KR20100067967A - Device and treatment method of wastewater contained distillate occurring at waste oil-recycling-process - Google Patents

Abstract

PURPOSE: A processing method of wastewater containing distillate produced in a waste oil production process and a device thereof are provided to effectively purify the non-biodegradable wastewater containing distillate, and to recycle oil components remaining in the wastewater. CONSTITUTION: A processing method of wastewater containing distillate produced in a waste oil production process includes the following steps: separating low boiling point oil from the wastewater containing oil by a stripping process; separating high boiling point oil and moisture from the wastewater by a vacuum evaporation process and a concentration and drying process; processing the wastewater while removing a foul odor from the wastewater; and sintering the foul odor by a regenerative thermal oxidizer process.

Description

Device and treatment method of wastewater contained distillate occurring at waste oil-recycling-process

The present invention relates to a method and apparatus for treating oil-containing wastewater generated in a waste oil regeneration process, and more particularly, to a wastewater containing a large amount of oil generated in a process of collecting waste oil and waste lubricating oil and regenerating it as fuel with high efficiency. As a treatment technology, it relates to a technology for separating flammable oil components for recycling and a technology for effectively purifying hardly decomposable wastewater containing a high concentration of chemical oxygen demand (COD) and severe odors such as mercaptans after separation. .

 In general, wastewater containing a large amount of oil generated in the process of collecting waste oil and waste lubricant oil and regenerating it as fuel is currently treated by using a specific gravity difference or using an oil / water separator to separate the oil and combine adsorption. Although the method is used, it is difficult to separate completely, and especially in the case of water-soluble oil, it is difficult to separate, so it is treated as a waste and incinerated.

In the treatment of wastewater containing oil, if wastewater treatment is carried out in the presence of oil, chemical treatment is not possible and high COD is caused by water-soluble oil. Organic loads and biotoxins do not allow for continuous treatment of wastewater, which has resulted in many economic burdens and inefficiencies due to the high energy input and incineration.

In addition, the oil is reused by installing waste oil refining facilities to reuse the waste oil or lubricating oil as described above. However, a small amount of oil and water-soluble oil are discharged together with the waste water, and the waste water cannot be purified without special technology. to be.

In particular, the oil-containing wastewater is difficult to treat, but above all, it is important to solve the problem of removing the oil and the odor spreading around the wastewater treatment. The oil containing water-soluble oil is mixed with low boiling point compound and high boiling point compound, so when boiling by separation, low boiling point compound and water are evaporated together in the distillation column. At this time, the low boiling point oil must be present in the condensate at a minimum to facilitate the wastewater treatment. Therefore, the oil must not be condensed entirely, and must be incinerated to be incinerated.

On the other hand, most water and high-boiling compounds that have not been evaporated in the distillation column should be sent back to the evaporator to evaporate and condense the water to be transported to the wastewater treatment plant. The high boiling point compound and some water are sent back to the dryer to finally remove the water, and the high boiling point oil component is taken out and stored and recycled. However, the important problem is to separate the water and oil well, Increasing purity is the biggest challenge.

The present invention has been made to solve the above problems, in the treatment of oil-containing wastewater generated in the waste oil regeneration process to extract the oil components remaining in the waste water with high purity to be reused as fuel and oil and oil In order to effectively purify the removed hardly degradable wastewater, and to provide a method and apparatus for treating oil-containing wastewater, which can be almost completely treated with only a small amount of energy.

In order to achieve the above object, the present invention provides a first stripping process for separating low-boiling oil from oil-containing wastewater and secondary vacuum evaporation and concentrated drying for separating high-boiling oil and water from oil-containing wastewater. 3rd advanced treatment process to remove odor by using microorganisms in wastewater with high process and chemical oxygen demand and to treat wastewater, and 4th heat storage type thermal incineration to incinerate odor generated in the 1st, 2nd and 3rd processes It is configured to process, the first and second separators used in the first and second process is provided with a washing column in the form of a serrated bubble cap tray, the secondary evaporator is configured to be equipped with a coil-type preheater on the top of the evaporator do.

According to the configuration of the present invention as described above, in treating the oil-containing wastewater generated in the waste oil regeneration process, the oil component remaining in the wastewater can be extracted with high purity and reused as fuel, and the oil-containing wastewater by effectively purifying the hardly degradable wastewater. It is a very economical and useful invention that can process almost completely, and can process more efficiently than other methods even with a small amount of energy.

In order to achieve the above object, the present invention provides a first stripping process for separating low-boiling oil from oil-containing wastewater, and for separating high-boiling oil and water from oil-containing wastewater. Secondary vacuum evaporation and Concentration and Drying process and wastewater with high concentration of chemical oxygen demand (COD) are adsorbed by high odor component in organic oxidation treatment device and then microorganisms are used. 3rd Advanced Biological Treatment process to treat wastewater and 4th Regenerative Thermal Incineration (RTO) process to incinerate odors caused by volatile organic compounds generated in the 1st, 2nd and 3rd processes. do.

Hereinafter, described with reference to the accompanying drawings a preferred embodiment according to the present invention.

1 is a schematic diagram schematically showing an apparatus for treating oil-containing wastewater according to the present invention.

Referring to Figure 1, the main components of the present invention and the arrangement order of the sump tank 10, the primary distillation tower (Stripping Tower 100), the primary separator (110), the secondary distillation tower (Stripping Tower) (101), Secondary Separator (111), Primary Evaporator & Bubble Cap Type Separator (200, 210), Secondary Evaporator & Bubble Cap Type Separator (201, 211) It consists of a vacuum dryer (Vacuum Dryer) 400, regenerative thermal oxide (Regenerative Thermal Oxidizer) (300).

The oil-containing wastewater stored in the sump (10) is introduced into the primary distillation column (100) through the primary and secondary preheaters by a feed pump. The introduced waste water is circulated to the circulation pump in the primary distillation column 100 and sent to the secondary distillation column 101 and circulated in the same manner as the primary distillation column 100.

The oil-containing waste water circulated in the first and second distillation columns (100, 101) is evenly distributed in the tube by the spray nozzle at the top of the distillation column and flows down into the tube in the form of a film while exchanging heat with the steam thermal energy supplied to the body of the distillation column to lower the boiling point of COD. The condensate condensed in the condenser is recycled and the noncondensable gas is sent to a regenerative heat incinerator (RTO) 300 to oxidize at high temperatures.

The high boiling point oil-containing wastewater introduced into the depressurization evaporator in the distillation tower (100,101) is circulated by the circulation pump in the primary and secondary evaporators (200,201) and is evenly distributed to the tube by the upper spray nozzle of the evaporator and the wastewater flowing down the inner wall of the tube is The high boiling point fuel component and water are separated by steam heat energy of the evaporator body, and the condensed water condensed is transferred to a wastewater treatment plant, and the high boiling point fraction, which is a residue, is sent to the dryer 400 for final concentration.

In addition, when the evaporation occurs, the high boiling point oil in addition to the vaporized water is splashed in a state that does not vaporize. To solve this problem, the bubble cap tray 201 is installed and washed with water to return to the sump tank. Only the vaporized water is condensed in the condenser and sent to the wastewater treatment process.

The high boiling point oil-containing wastewater introduced into the dryer 400 is a finishing process for minimizing water, and the steam heat energy of the dryer jacket is transferred to the high boiling point oil-containing wastewater inside the fuselage and rotates with a stirrer to evaporate water.

At this time, the final concentrated oil is recycled and the evaporated water is condensed in the condenser and sent to the wastewater treatment plant for treatment.

The following is a table summarizing the data investigated by the pilot test the amount of oil contained in the waste water by each process according to the present invention as described above.

Table 1) Mass Balance of Oil by Process

Oil content in stock solution
80 (kg / ton) Stripping gas volume Evaporation Condensate Content Sum 5 kg 71 kg 4 kg 80 kg

In addition, the following table summarizes the data of the average COD change in the wastewater by the pilot test according to the present invention through a pilot test.

Table 2 Average COD Change by Process

By process Influent After stringing After evaporation After biological treatment COD value (ppm) 15,500 14,200 5,220 21

In addition, the main components of the present invention will be described in detail as follows.

The first distillation column 100 is installed to minimize the oil to be evaporated with the waste water containing the oil during evaporative condensation, the waste water sprayed from the spray nozzle is installed on the top of the distillation column is a vertical thin film falling tube (Tube) As the waste liquid descends in the form of a film on the inner wall, evaporation takes place by heat exchange with the steam on the fuselage side, the vaporized steam passes through the separator, the condensate is refluxed in the condenser, and the non-condensable material is led to the duct, which is incinerated in the incineration plant. Is processed.

The primary separator 110 connected to the primary distillation column 100 and installed thereafter is installed to separate droplets splashed with the vapor evaporated from the primary distillation column 100 and condenses water vapor by condensing water vapor. It serves to lower the concentration.

The secondary distillation column 101 is a device having the same structure and the same function as the primary distillation column 100, and serves to improve thermal efficiency by reusing steam by performing a second stage treatment after the primary distillation column 100.

The secondary separator 111 has the same structure as the primary separator 110 and has the same function and is installed with the secondary distillation column 101 to separate the vaporized vapor and the accompanying droplets. to be.

The primary evaporator 200 and the separator 210 are facilities for evaporating water and concentrating the oil to a high concentration in the wastewater containing the high boiling point oil remaining after separating the low boiling point oil from the first and second distillation columns 100 and 101. .

The principle that the primary evaporator 200 and the separator 210 performs the role of evaporating water and concentrating the high boiling point oil to a high concentration is the spray of waste water from the spray nozzle on the top of the evaporator 200 and the injected waste water is vertical As the film is lowered on the inner wall of the thin-film falling type tube, the high-boiling oil is concentrated while being heated by reusing the vapor evaporated from the fuselage side secondary evaporator 201. After droplets are separated from the separator 210 by the vapor evaporated from the evaporator 200 and the droplets are droplets, the droplets are absorbed and removed by the water supplied to the bubble cap tray 212 installed at the top of the separator 210 to be contained in the droplets. Prevents COD concentration rise due to oil fraction.

The secondary evaporator 201 and the separator 211 serve as the primary evaporator and separator, but it is distinguished that steam used in the fuselage is not reused and uses new steam. The coil type preheater 202 mounted to the evaporator 201 of the secondary evaporator 201 and the separator 211 flows wastewater having a low temperature of the primary evaporator 200 into the secondary evaporator 201. It is installed to raise the temperature before making it.

FIG. 2 is a structural diagram showing a structure of a bubble cap tray installed in a separator according to the present invention. Referring to FIG. 2, a washing column is collected in the separators 210 and 211 to collect only droplets while minimizing condensation of steam. Mount the serrated Bubble Cap Tray (212) on it.

The separators 210 and 211 separate the gas and the liquid in the water evaporated from the evaporator, and the gas separated from the separator 210 becomes condensed water in the next condenser, is transferred to the next wastewater treatment process, and the gas separated in the separator 211 is It is sent to the evaporator 200 to become an evaporation heat source, and the heat exchanger condenses itself and is transferred to the next wastewater treatment process. These condensed water is not possible to treat wastewater by microorganisms, even if only a small amount of oil is contained to install the bubble cap tray on the top of the separator to prevent condensation of the oil to minimize the condensation of the oil.

Water is sent to the sawtooth bubble cap tray 212 installed in the separators 210 and 211 to absorb the droplets containing the entrained oil into the water, and only pure water vapor is sent to the condenser or the primary evaporator 200.

Therefore, by mounting the bubble cap tray 212 it is possible to significantly lower the COD of the separated waste water by blocking the outflow caused by the overflow of oil components due to the azeotropy generated in the conventional concentrator.

3 is a structural diagram illustrating a structure of a coil type preheater installed in the secondary evaporator of the present invention. Referring to FIG. 3, a coil type preheater (2) is formed on the evaporator 201 of the secondary evaporator and separators 201 and 211. By mounting the preheating 202 in advance, the efficiency of the secondary evaporator 201 is doubled to save energy.

After the evaporation of water in the first evaporator 200, the concentrated residue contains a considerable amount of water, so it is necessary to send water back to the second evaporator 201 to remove water. The temperature of the first evaporator is about 63 ° C. to a low temperature. Since it operates at 100 ° C, the inlet temperature of the secondary evaporator is less than 63 ° C, and the evaporation efficiency is very low. Therefore, a high-efficiency evaporator is needed to make high-purity refined oil, and by installing a coil type preheater on top of the evaporator, this problem can be solved by making the evaporation residue almost oil-free.

Figure 4 is a schematic diagram schematically showing a third advanced treatment process of the oil-containing wastewater according to the present invention.

Referring to Figure 4, the organic material of the waste water condensed in the reduced pressure evaporation process is adsorbed by the adsorbent added through the adsorption oxidation process 500, the organic material is adsorbed by the following neutralization, reaction, flocculation, precipitation, COD-inducing material After removal, the biological treatment facility 600 is discharged or reused after the final treatment by the microorganism.

5 is a schematic diagram schematically showing a heat storage type thermal incinerator according to the present invention.

Regenerative Thermal Oxidizer (RTO) is a device that incinerates using only a small amount of energy.In general, incinerators have to consume a lot of energy because incinerators have to be incinerated at temperatures above 800 ℃. However, the regenerative incinerator has the same temperature in the furnace, but stores heat energy in the heat storage material while emitting 800 ° C. heat, and exports it below 70 ° C., and recycles the regenerated energy, thereby saving energy of 90% or more compared to simple incineration.

The present invention is applicable to the regeneration and purification process of all kinds of oil-containing wastewater, including waste oil and waste lubricant oil.

1 is a schematic diagram schematically showing an apparatus for treating oil-containing wastewater according to the present invention

Figure 2 is a structural diagram showing the structure of a bubble cap tray installed in the separator according to the present invention

Figure 3 is a structural diagram showing the structure of a coil type preheater installed in the secondary evaporator of the present invention

Figure 4 is a schematic diagram schematically showing a third advanced treatment process of the oil-containing wastewater according to the present invention

Figure 5 is a schematic diagram schematically showing a heat storage type thermal incinerator according to the present invention

[Description of Reference Numerals]

10: sump tank 100,101: distillation column

110,111,210,211: Separator 200,201: Evaporator

202: coil type preheating device 212: bubble cap tray

300: regenerative heat incinerator 400: concentrated dryer

500: adsorption, oxidation facility 501: adsorption oxidant input device

510: organic material adsorption oxidation facility 511,621: caustic soda

512,622 Poly iron 513,623 Polymer

520,630: flocculation facility 530,610,611: precipitation facility

531,612,641: pump 532,613: dehydrator

540: flow rate adjusting facility 541: conveying sludge

550: underground aeration facility 600: biological treatment facility

620: reaction facility 640: final treatment tank

650: Filtration facility 660: Discharge, reuse

Claims (3)

In the method of treating oil-containing wastewater generated in the recycling process of waste oil, Primary stripping process for separating low boiling oil from oil-containing wastewater; and A second vacuum evaporation and concentration and drying process for separating high boiling oil and water from oil-containing wastewater; and Advanced Biological Treatment for removing odors and treating wastewater using organic oxidizers and microorganisms in wastewater with high chemical oxygen demand (COD); And Treatment method of oil-containing wastewater generated in the waste oil regeneration process, characterized in that consisting of a fourth-order regenerative thermal oxidizer (RTO) process incineration of odor generated in the first, second and third process. . Water collection tank (10), primary and secondary distillation columns (100, 101), primary and secondary separators (110, 111), primary evaporator (200) and separator (210), secondary evaporator (201) and separator (211), heat storage type incinerator (RTO, 300), in the oil-containing wastewater treatment device consisting of a concentrated dryer 400, The separators 210 and 211 are equipped with a sawtooth bubble cap tray 212 in a washing column to collect only oil droplets while minimizing condensation of steam. Treatment device for oil-containing wastewater generated Water collection tank (10), primary and secondary distillation columns (100, 101), primary and secondary separators (110, 111), primary evaporator (200) and separator (210), secondary evaporator (201) and separator (211), heat storage type incinerator (RTO, 300), in the oil-containing wastewater treatment device consisting of a concentrated dryer 400, Treatment of oil-containing wastewater generated in the waste oil regeneration process, characterized in that the refined oil of high purity is manufactured by mounting a coil type preheater 202 on the evaporator 201 of the secondary evaporator 201 and the separator 211. Device

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