KR20020010384A - Method and equipment for continuous vacuum thermal regeneration of adsorbent and recovery of adsorbate - Google Patents

Abstract

PURPOSE: A method for continuous vacuum thermal regeneration of adsorbent and equipment thereof is provided, which can regenerate adsorbent at medium temperatures of ambient temperature to 200 deg.C at vacuum of 0 to 70 Torr varying the conditions according to recovering substance and recover useful substances regenerated from the adsorber without burning useful substances contained in VOC. CONSTITUTION: The recovery and separating equipment comprises three recovery tanks(14), two oil-less vacuum pumps(1,20), a pressurized condenser(25), a heater(12) and heat exchangers(15). The adsorbing towers(8) of more than two are set in parallel and operated by pressure swing steps. During adsorption step gas is passed through the adsorbing tower(8) that is in adsorption and is exhausted to outside by an induced draft fan(2) with other towers being regenerating and recovering step. During regenerating step the system is isolated and kept at vacuum of 0 to 70 Torr by a vacuum pump(16) and heated to ambient temperature to 200 deg.C by a heater(6) and regenerated gas from the towers are compressed by a compressor(24) and condensed by a pressurized condenser(18) and stored at a storage tank(23).

Description

Method and apparatus for continuous vacuum thermal regeneration of adsorbent and separation recovery of adsorbent materials {Method and equipment for continuous vacuum thermal regeneration of adsorbent and recovery of adsorbate}

The present invention relates to the field of air pollution control and waste recycling in the field of environmental engineering, and the detailed field is a method of continuously regenerating waste adsorbents of the adsorption method for treating odors and VOCs and recovering desorbed substances.

As the existing technology, most odors and VOCs generated in most industrial sites are mostly hydrocarbons and some inorganic gases are included at the same time. The conventional methods of removing odors and VOCs are mainly incineration by heat, catalyst incineration, and aqueous solution. Absorption (including chemical oxidation), adsorption by adsorbents such as activated carbon (Adsorption), condensation, catalyst incineration, photocatalytic oxidation and the like have been used, and biofilters (Biofilter) have recently been used. Each of these treatment methods has advantages and disadvantages for each application depending on the source of each pollutant generation, and all treatment methods have their problems in general application. The adsorption method is currently spreading in part to develop a method for continuously regenerating the adsorbent by using a high temperature and high pressure steam to regenerate the physically adsorbed material.

The present invention is an improvement of the existing adsorption method and the method of regeneration using water vapor.

① Various compounds can be processed from high concentration to low concentration.

② It has high efficiency of over 99% before break point

③ Depending on the type of adsorbed material, various kinds of adsorbents (activated carbon, silica, activated alumina, etc.) can be used to increase the efficiency.

But the biggest drawback in field adaptation is

① The breakthrough point is reached in a short time depending on the concentration and the type of pollutant. After that, the efficiency is close to 0%.

② Breakthrough activated carbon is expensive to replace, and the adsorbed material useful for regeneration of activated carbon is disposed of by incineration.

In order to remedy the above disadvantages, the regeneration and recovery method using water vapor is introduced into the existing activated carbon adsorption tower to decompress the adsorbent by introducing high temperature and high pressure water vapor, and the hydrocarbon compound condensed and recovered with water is separated from the oil and water to recover useful materials. The advantage of this method is that it can recover the useful materials and use the regeneration tower continuously, but it has the disadvantage of requiring a boiler facility for producing and supplying steam and a wastewater treatment facility for reprocessing condensate.

An object of the present invention was developed to solve the problems of the odor and volatile organic compounds removal method by the conventional adsorption,

① It retains the advantages of the existing adsorption tower,

② By regenerating adsorbent continuously, it can drastically reduce the replacement cost and secure stable high efficiency treatment.

③ The material to be adsorbed can be recovered according to the physical properties, thus reducing raw materials.

④ No secondary pollution problem such as waste adsorbent and waste water

⑤ It can secure an economic advantage in terms of installation cost and maintenance cost than existing high efficiency treatment methods such as incineration, catalytic oxidation and biofilter.

⑥ It can provide an ideal method of treating odors and VOCs that can regenerate adsorbents directly in the adsorption column and recover odors and volatile organic compounds (VOCs).

1 is a representative processing process and apparatus diagram of a method for continuously regenerating an adsorbent and separating and recovering adsorbent materials according to a first embodiment of the present invention. Fixed Bed Adsorption Tower-> Vacuum Pump-> (Compression Pump)-> Pressure Condenser or Pressure Tank

FIG. 2 is an apparatus diagram of a pressurized tank which is a pressurized adsorbent recovery method replacing the condenser of FIG.

[Explanation of symbols on the main parts of the drawings]

1. Total hydrocarbon, flammable gas or gas concentration sensor 2. I.D. Fan

3.Pressure resistant tamper 4.Pressure regulating solenoid valve

5.Valve for cooling liquid or refrigerant flow rate 6.Heater for heating

7.Heat exchanger for heating inside the adsorption tower 8.Vacuum regeneration type fixed bed adsorption tower

9.digital vacuum gauge 10.digital thermometer

11.Solenoid Valve 12.Pneumatic Pressure Damper

13.Check valve 14.Gas collection hood

15. Confidential pressure resistant tamper 16. Oilless vacuum pump (dry pump)

17.Pressure regulating valve 18.Pressure condenser

19.Pressure regulating valve 20.Coolant or refrigerant circulation pump

21.Control Panel 22.Cooling water, heat fluid, refrigerant supply

23. Recovery liquid separation storage tank 24. Gas compressor

25.Pressure control valve 26.Unrecovered gas outlet (towards prevention facility)

27.Pressure regulating valve 28.Level sensor

29. Pressure gauge 30. Coolant outlet

31.Pressure condensation tank 32.Recovery tank cooling heat exchanger

33.Level gauge 34.Coolant inlet

35. Solenoid valve for discharge liquid 36. Flow sensor

37. Recovery outlet (to condensate storage tank) 38. Reduced recovered odors and VOCs

39.Oilless vacuum pump (dry vacuum pump) 40.Gas compressor

As a representative treatment process and apparatus diagram of the present invention for achieving the above object, the process configuration is a vacuum adsorption tower (8), vacuum pump (16), and a gas compressor (if necessary) to continuously recover the activated carbon adsorption column and separate and recover the adsorbed material. 24), a pressure condenser 18 or a pressure condensation tank 31. Specifically, in FIG. 1, the vacuum fixed bed adsorption device 8 is installed in a structure capable of high vacuum and warming, and one or more units are connected in parallel, and the adsorption tower reaching the break point depends on the type of material to be desorbed. The oilless vacuum pump (16) at a proper pressure to depressurize and at the same time heated to the appropriate temperature (7) (6) by separating and desorption by material to regenerate the adsorbent to be used continuously. In addition, the desorbed adsorbent is connected to the gas compressor after the vacuum pump if necessary, the temperature is reduced to room temperature or lower in the pressure condenser (18), and the pressure control valve (17) is installed at the rear of the condenser to increase the pressure inside the condenser Condensation by compression (39) or (39) + (40) using a pressurized condensation tank (31) capable of maintaining condensation recovery or reducing the temperature and pressure with the heat exchanger (32). Recovery was possible.

Each detailed apparatus includes a total hydrocarbon in the vacuum regenerative fixed bed adsorption tower 8, a flammable gas or gas concentration sensor 1 after the outlet of the adsorption tower, and an airtight pressure resistant tamper 3 at the inlet and outlet of the vacuum regenerative fixed bed adsorption tower. ), A pressure relief valve (4) for regulating the pressure to atmospheric pressure after vacuum desorption, to prevent the internal temperature rise by vaporization heat during desorption of the internal temperature of the adsorption tower for desorption, heat exchanger (7), cooling water or thermofluid, refrigerant Heating device (6) for heating the gas, a flow control valve (5), a thermometer (10) and a vacuum gauge (9) installed before the activated carbon adsorption layer, and a solenoid valve (11) for vacuuming the interior of the vacuum regeneration fixed bed adsorption column. ) And the check valve 13, the oilless vacuum pump 16 and the gas compressor 24, etc. are installed in series or in part and characterized in that the control panel to automatically control.

In the method of separating and recovering the desorbed material, the oilless vacuum pump 16 alone or the gas compressor 40 are continuously installed and the recovered material is atmospheric pressure or pressurized using the pressure regulating valves 17, 25 and 27. To the condenser 18 or the pressurized condensation tank 31. The condensation heat generated at this time is a pressurized condensation in which a circulation pump 20, a pressure control valve 19, a supply line 22, and a condenser 18 or a heat exchanger 32 are provided to supply and circulate cooling water, a thermal fluid or a refrigerant. Cooling using the tank 31, at this time uncondensed gas is returned to the prevention facility inlet through the pressure control valve (17) (25) (27) and reprocessed, the pressure gauge (29) for safe operation and control Are attached to the condenser 18 and the pressurized condensation tank 31, and the level sensor 28 and the level gauge 33 are attached to the pressurized condensation tank 31, respectively. All or some of the above sensors and devices are installed and characterized in that they are automatically controlled from their control panel.

The advantage of the present invention is the basic characteristics of the treatment method by adsorption in the existing air pollution prevention facilities, the most advantage of the polar or non-polar gas can be treated with high efficiency according to the selection of the adsorbent, the adsorbent in the field in the continuous adsorption tower By changing the structure to be regenerated, continuous regeneration in the field eliminates the need to replace the adsorbent or extends the replacement cycle several times or tens of times, thereby reducing the cost of replacing the adsorbent and at the same time The possibility of excess emissions of pollutants can be blocked at source. In this case, the on-site regeneration method of the adsorbent allows the inside of the adsorption tower to be vacuumed, and the oilless vacuum pump depressurizes the inside of the adsorbent and heats it if necessary based on the heat of condensation generated when the desorbed adsorbent is condensed. By raising and lowering the inside of the adsorption column in order to separate and desorb by materials, it is possible to separate and recover useful materials in the waste gas by materials, thereby improving the purity of the recovered materials and improving economic efficiency. Eliminates the need for additional expensive installations, such as start-up of boilers and wastewater treatment plants. The desorbed adsorbent is provided with a compressor capable of compressing the desorbed gas alone or at the rear end of the vacuum pump according to the type and physical properties of the adsorbent, and pressurized to condense using a cooling water, a cooling fluid, or a refrigerant as a coolant. Type condensers or pressurized tanks were installed to facilitate the recovery of useful materials. As a result, the operation and maintenance of the adsorption tower is inexpensive, and activated carbon contained in the device can be reused over a long period of time, and the substances desorbed from the device are recovered and reused with high efficiency and discharged from the workplace. It is possible to fundamentally reduce the amount of volatile organic compounds used, so that there is no secondary pollution, and the annual cost for preventing air pollution can be greatly reduced.

The present invention mainly handles high concentrations of odors and VOCs with high efficiency of 99% or more according to the configuration and operation conditions of the device, and the biggest advantage is easy to maintain and easily applicable to small-scale facilities, and existing prevention technology. Maintains the basic characteristics by adsorption in the middle as it is, while maintaining the operating state of the adsorbent in the vacuum fixed bed adsorption can be recycled by vacuum, heating, and the material recovered and separated can be reused as a raw material.

This improves the shortcomings of short-term saturation and excessive cost of adsorbent replacement, which are disadvantages of conventional adsorption towers (activated carbon, activated alumina, etc.), and maintains high efficiency that can be applied to various concentrations of various pollutants. In addition, there is no generation of secondary pollutants such as waste water and waste, and the cost can be reduced annually.

Application facilities of the present invention include all facilities equipped with existing activated carbon adsorption facilities, high-density gas supply facilities, low gas stations, laundry facilities, urban small and medium-sized facilities, petroleum refining and petrochemical production facilities, organic solvents and paint production and It can be applied to odor and VOCs emission facilities of industrial complexes such as application facilities, and can be installed in large and small and medium sized and high to low concentrations of odor and VOCs emission sources to process pollutants stably and efficiently. In this case, it is possible to economically reduce odor and VOCs emission, thereby reducing odor complaints, and greatly reducing secondary air pollution by photochemical reaction.

Claims (11)

Continuous vacuum regenerative adsorption method characterized by desorption with an oilless vacuum pump with a vacuum of 0-70 Torr to recover on-site adsorbents of odor and volatile organic compounds (VOCs, Volatile Organic Compounds) The damper or valve for maintaining the internal vacuum at the inlet and outlet of each continuous vacuum regenerative adsorption apparatus, the pressure gauge for adjusting the degree of vacuum in the main body, the solenoid valve for proper operation of the vacuum pump, the check valve, the uncondensed gas recovery Continuous vacuum regenerative adsorption method characterized in that all or part of the pressure relief valve connected to the line is installed and automatically controlled by the control panel sequentially The main heat source is the heat of condensation that is discharged during the condensation of substances desorbed between 0-70 Torr vacuum and room temperature -200 ℃ to recover on-site adsorbent of adsorption tower for processing odor and volatile organic compounds (VOCs). Continuous vacuum heating regenerative adsorption method characterized in that the vacuum heating desorption using The method of claim 3, wherein in the continuous vacuum heating regenerative adsorption apparatus, a thermostat, a heat exchanger, a flow regulating valve, a heater for auxiliary heating, etc., are installed in the main body in whole or in part, and these are automatically controlled sequentially by a control panel. Continuous vacuum heating regenerative adsorption method characterized in that Mutual heat exchange with pressure control valve, uncondensed gas recirculation line and adsorption tower at the back of oilless vacuum pump to recover odorous substances and volatile organic compounds (VOCs), which are desorbed from adsorption column, at room temperature and atmospheric pressure. Odor and VOC material condensation recovery method characterized in that by installing and recovering a pressure condenser or a pressure condensation tank with a heat exchanger. The pressure condenser or pressurized condenser tank is operated under a relative atmospheric pressure of 0.5 to 0.5 atm, and the uncondensed gas is connected to the front end of the prevention facility to be reprocessed and the condensation heat is cooled by heat exchange with the vaporization heat when the adsorption tower is desorbed. Odor and VOC material condensation recovery method. In order to recover odors and volatile organic compounds (VOCs, Volatile Organic Compounds) desorbed from the adsorption column, a pressure pump is continuously installed at the rear of the oilless vacuum pump to recover the gaseous substances at normal temperature and atmospheric pressure. Odor and VOC material pressurized condensate recovery method characterized in that the installation and recovery of a pressurized condenser or a pressurized condensation tank with a heat exchanger for mutual heat exchange with the gas recirculation line and the adsorption tower. The pressurized condenser or pressurized condensing tank is pressurized to a relative pressure of 0.2 to 6 atm according to the type of material, the uncondensed gas is connected to the front end of the prevention facility, and the heat of condensation is the heat of vaporization when the adsorption tower is desorbed. Odor and VOC material pressure condensation recovery method characterized in that the cooling by heat exchange with. The discharge of the liquid condensed and recovered by the level sensor for detecting the water level of the main body in the pressurized condenser or the pressurized condenser tank, the solenoid valve for discharging the discharge liquid, the flow sensor, the temperature sensor for controlling the internal temperature, and the control panel Odor and VOC material pressurized condensation recovery method characterized in that the automatic control. In air pollution prevention facilities, a concentration sensor of the target component gas is attached between the outlets at the rear end of the main body of the prevention facility, and in the non-continuous discharge facility, a gas tight damper between the main body of the prevention facility and the airtight damper between the main body of the prevention facility and the outlet A vacuum pressure sensor is installed between the airtight dampers to control the operation of the air pollution prevention facility by changing the concentration sensor and the vacuum pressure sensor. The airtight damper between the hood and the main body of the prevention facility is operated in connection with the operation of the discharge facility, and the airtight damper and the blower between the main body of the prevention facility and the outlet are controlled by a vacuum pressure sensor. Method of automatic control of the facility.