KR20070082493A - The method to seize volatile organic compounds by using mist of organic solvents - Google Patents

Abstract

A method for trapping volatile organic compound is provided to liquefy gas to be trapped, thereby easily managing the gas to be trapped, by contacting the gas to be trapped with a surface of liquid so as to dissolve the gas to be trapped in the liquid and physically collecting droplets containing the gas to be trapped. A gaseous volatile organic compound is trapped or collected by contacting a gaseous material with a hydrocarbon-based organic solvent. Herein, the hydrocarbon-based organic solvent is sprayed in a fine particle type or a mist type within a space where the gaseous material is present. A solution, where halogen-based hydrocarbon is mixed to the spray solution, is used for a safety measure against fires or an increase in collecting efficiency of the organic compound.

Description

The method to seize Volatile Organic Compounds by using mist of organic solvents}

1 is a schematic diagram of a scrubber.

       (11): VOC inlet

       (12): organic solvent inlet for spraying

       (13): mist spray nozzle

       (14): Mixing zone of spray fog and VOC

       (15): scrubber cell

       (16): collecting solvent outlet

       (17): clean gas discharge

       (18): detail view of spray nozzle

       (19): scrubber cell detailed view

2 is an example of a spray liquid circulation system

       (21): maze-type scrubber body

       (22): spray liquid reservoir

       (23): spray pump

       (24) spray side filter

       (25): Recovery liquid side filter

       (26): waste liquid storage tank

       (27): concentration control valve

       (28): additive storage tank

[Figure 3] Scrubber used in the experiment

The present invention is a method for trapping a gaseous substance composed of benzene, toluene, xylene, also known as BTX, as well as an organic compound called VOC, so that fine organic solvent particles having good solubility with organic matter in a duct or chamber through which gas passes. The present invention relates to a method of collecting VOCs in a duct or chamber by spraying the particles with VOCs to dissolve the VOCs in the organic solvent particles and then recovering the organic solvent particles using a scrubber capable of collecting particulates.

That is, the technology to be achieved by the present invention belongs to the technology related to the recovery of VOC in the gas handling process as well as the technology related to the emission control of air pollution prevention and odor prevention technology.

      The uniqueness of the present invention induces the flow path of the gas to the left and right to induce the fluid to pass through the rotation left and right, by using the centrifugal force generated at this time in the inertia of the droplet to collect on the wall of the maze form to collect the droplets A scrubber is used to collect VOCs by spraying organic solvents into particulates of 100 microns or less in a gas containing VOCs.

      Conventionally, although water containing additives is contacted and recovered by contacting VOCs using a spray and a filling material of 500 microns or more in a packing tower, some experiments have been conducted to collect VOCs by spraying petroleum in the packing tower. The method was not easy to get enough area and time for the droplet to actually contact the gas even if the droplet was bulky and filled, and the efficiency in the packing tower was extremely small, and for such reasons, Using a packed tower was difficult.

 The problem of spraying liquid and contacting gas with the surface area of spray droplets is that the surface area becomes wider and the efficiency increases as it is atomized. However, in order to achieve this, a method for acquiring and recovering the atomized droplets from the rear stage must be accompanied.

In addition, even in the case of fine droplets, similar chemical functional groups of gaseous organic substances are easily absorbed in the collection of VOCs. For example, the first priority is the question of whether VOC is hydrophilic or hydrophobic, and what functional groups it can act as an important factor for absorption.

However, in the gas mixture with air, the finer the droplets, the more the contact with oxygen becomes, and the risk of explosion is also considered.

In the present invention, the gas is concentrated in contact with the surface of the liquid by using the solubility of the gas in the solvent to collect the gas, the gas is dissolved in the liquid, and the liquid droplets are dissolved by recovering the liquid by physical methods, It relates to a method having the purpose of liquefying the gas to be collected to facilitate handling.

       The present invention is primarily directed to thinners, such as benzene or toluene xylene, that are commonly used for paint dissolving or cleaning agents, or to devices that use water as the solvent primarily in a variety of methods, such as filling towers or washing towers or similar organic solvents. It was conceived that the absorptive power was inferior, and the atomizing spray was used in order to use as much surface area as possible.

However, the present invention has its own solution.

Most of the organic solvents to be used in the present invention are susceptible to fire, and in particular, the atomization is accompanied by an explosion risk as the contact area with oxygen increases. As a solution to this point, the present invention provides a halogenated hydrocarbon.

It was solved by diluting with general hydrocarbon type, and it was helpful for recovery because the specific gravity of halogen type hydrocarbon is 1.2 ~ 1.3 heavy.

     Part of the present invention is to spray a small amount of solvent in order to capture the gas as much as possible, but the mist-type spray is efficient, which must be accompanied by a technology that can collect the fine atomized particles after spraying, non-polar VOC such as BTX As an alternative to the conventional washing towers using water, it is intended to increase efficiency by using non-volatile organic solvents.

The configuration of the present invention can be divided into a circulating system of the scrubber and the spray solution for the scrubber operation of the [FIG.

In FIG. 1, when the VOC flows into the inlet port 11 of the scrubber having the stacked structure of the scrubber cells 19 constituting the labyrinth, the mist spray nozzle 11 is sprayed from the sprayed liquid system 12 Spray the solution into a mist state.

The sprayed mist-like atomized liquid is mixed with the VOC in the scrubber mixing zone 14 and collides with the VOC, and passes through the scrubber cell 15 with the particles containing VOCs. While colliding, it is collected on the wall of the cell and flows down into the liquid state, and the collected liquid enters the spray liquid circulation system through the discharge pipe 16 again, and the clean gas from which the VOC is removed is discharged through the exhaust port 17.

    In the present invention, the circulation system of the spray liquid may vary depending on whether the collected liquid is combusted with fuel or distilled for recycling, but the simple circulation as in the case of [FIG. 2] to help the present invention is understood. Take the system as an example.

In FIG. 2, the liquid of the spray liquid storage tank 22 is sprayed in the particulate state in the scrubber 21 through the spray side filter 24 by the spray pump 23, and the recovered liquid is recovered liquid side filter 25. It is then circulated through the spray reservoir. Using the system for a certain period of time, if the filter on the recovery liquid side is clogged, backwashing is possible, and the backwashed liquid is stored in the waste liquid storage tank 26 for post-processing. The circulating fluid lost by backwashing during use is supplemented through the concentration control valve 27, and if the additive is necessary due to the nature of the system, the lower end of the concentration control valve is connected to the additive reservoir 28 so as to be diluted to a certain concentration. do.

Examples of experiments carried out as examples for grasping the effectiveness of the present invention are described below.

For the experiment was prepared a device having a mechanical configuration of [1] and [2], the specifications are as follows.

<Specification of experimental device>

        Scrubber cell size (mm): 900 x 400 x 350

        Aeration area of the cell (mm): 900 x 200

        Flow rate (m / s): 2.5

        Throughput Speed (m3 / min): 27

        Spray Nozzle Number / Spray: 40 / 3.72 lpm

        Spray rate (lpm) per nozzle: 0.093 lpm

        Spray average particle diameter (㎛): 30

        Spray Pressure (bar): 40 max

        Liquid ratio (spray liquid / gas m3): 0.186

Representative spray organic solvents used to confirm the actual gas collection efficiency in the above device conditions are as follows.

<Spray Solvent>

Solvent 1. Spindle base oil (manufacturer: Ssangyong Refinery Oil)

       Specific gravity (15/4 ℃): 0.88

       Kinematic Viscosity (40 ℃, cSt): 7.5

       Aromatic Content (wt%): 8.4

       Flash point (℃): 156

       Odor: None

Solvent 2. Paraffin chloride (manufacturer: Toyo Parax, Japan)

       Specific gravity (15/4 ℃): 1.25

       Chlorine Content (wt%): 50

      Kinematic Viscosity (40 ℃, cSt): 9

      Flash Point (℃): None

      Odor: None

Solvent 3. Base oil + paraffin chloride

        Mixing ratio: 50: 50%

        Specific gravity (15/4 ℃): 1.06

        Chlorine Content (wt%): 25

        Kinematic Viscosity (40 ℃, cSt): 8.2

        Flash Point (℃): None

        Odor: None

 In the example of combining the above-mentioned organic solvents and using them as a spray agent and acquiring acetaldehyde emulsion, laccasinna (a mixture of benzene, toluene, xylene, methyl ethyl ketone) and surfactant emulsion, which are difficult to collect with water, The same collection efficiency was obtained.

Entrance side Solvent 1 Solvent 2 Solvent 3 Concentration (ppm) Output concentration (ppm) efficiency Output concentration (ppm) efficiency Output concentration (ppm) efficiency Acetaldehyde 200 30 85 30 85 30 85 toluene 600 30 95 20 97 20 97 Methyl ethyl ketone 200 30 85 25 87.5 25 87.5 Mercaptans 100 20 80 25 75 25 75

The test results were detected using gastec, but not detailed figures, but the results of experiments with high concentration of VOC showed that the collection efficiency was superior to that of water.

These experimental results are continuously studied and more systematically established the proper solvent, injection speed, and flow rate, so that VOC prevention facilities, which are currently the main cause of air pollution, can be operated more efficiently. It can be used to capture or release the emitted gas.

Claims (3)

    A method of contacting a gaseous substance by spraying a hydrocarbon-based organic solvent in a particulate form or a mist of 100 microns or less in a space where a gaseous substance exists to collect or recover a gaseous volatile organic compound (VOC).     In order to collect the organic compounds in the form of particulates dispersed in the gas phase or arbitrarily dispersed in the concentrated phase, the flow path wall surface is made by using the inertia by the flow velocity of the gas phase in the cell induced to change the flow direction of the flow path at least five times from side to side. To recover the particulate phase dispersed in the gas phase into a liquid concentrated phase.     A method of using a solution containing halogenated hydrocarbons in a spraying liquid for the purpose of claim 1 as a safety measure against fire or for the purpose of increasing efficiency according to the characteristics of the organic substance to be collected.

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