JPS6034892B2 - Dry deodorization equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a dry deodorizing apparatus using an impregnated body of ozone, hydrogen bromide or hydrobromic acid, and an impregnated body of an alkali or alkali metal bromide.

Conventionally, as a dry deodorizing apparatus of this type, there has been a deodorizing apparatus equipped with a packed bed of hydrogen bromide-impregnated carbon and activated carbon as shown in FIG.

In the figure, 1 is a blower, 2 is a compressor, 3 is an ozonizer, 4 is a mixing tank that mixes the ozonized air sent from the ozonizer 3 with the air to be treated sucked by the blower 1;
5 is a reaction tower, 6 is a packed bed of impregnated carbon (hereinafter referred to as HBr-impregnated carbon) in which activated carbon is impregnated with hydrogen bromide or hydrobromic acid;
7 is an activated carbon packed bed. The foul-smelling treated air A is sucked through the blower 1', uniformly mixed with ozonized air fed from the ozonizer 3 in the mixing tank 4, and then introduced into the reaction tower 5.

In the reaction tower 5, first, in the HBr-impregnated carbon packed bed 6, bromine (Br2
) is generated. 2HBr 1003 → Br2 10th 2010
2...[1] In the HBr-impregnated carbon packed bed 6, the generated Br2 causes catalytic oxidative decomposition of malodorous components (mainly methyl sulfide, methyl mercaptan, etc.), and then in the activated carbon packed bed 7, excess After ozone was decomposed or bromine and the product sulfur dioxide gas were adsorbed and removed, it was released as treated air B.

In such equipment, since the HBn-impregnated carbon is acidic, acidic gases such as hydrogen sulfide are difficult to adsorb and must be removed by reaction with bromine. activated carbon layer 7 in the latter stage to adsorb
It was necessary to increase the amount of activated carbon loaded.

In addition, hydrogen sulfide contained in the gas to be treated A is HBr.
When it is oxidized in the impregnated carbon layer 6, it eventually becomes sulfuric acid, so
HBr, which is a weaker acid than sulfuric acid, is replaced by this sulfuric acid and sequentially moves from the inflow side to the outflow side of the processing gas A, and is finally dissipated into the air, so the amount of bromine impregnated decreases quickly and the service life is shortened. It had the disadvantage of being shorter. This invention was made in order to eliminate the above-mentioned drawbacks, and is provided with an impregnated body (hereinafter referred to as KB) in which an alkali or alkali metal bromide is impregnated on a carrier such as activated carbon on the downstream side of the HBh-impregnated carbon packed bed.
A packed bed of impregnated coal is provided, and in this packed bed, HB
The HBr diffused into the air from the r-impregnated carbon packed bed is supplemented, and malodorous components are also oxidized and decomposed in this packed bed by the oxidizing action of Br2.

FIG. 2 is a flow diagram showing an embodiment of the present invention, and 8 is a flowchart showing an embodiment of the present invention.
Packed bed of Br-impregnated coal (hereinafter referred to as KBr-impregnated coal packed bed)
It is.

Next, the operation will be explained. The air to be treated A containing the malodorous gas sucked in by the blower is uniformly mixed with the ozonized air fed from the ozonizer 3 while passing through the mixing tank 4, and then introduced into the reaction tower 5. In the reaction tower 5, in the HBr-impregnated carbon packed bed 6, most of the malodorous components are removed by an oxidation reaction similar to the conventional method. Hydrogen sulfide is reacted with ozone and reaction formula {1
} is decomposed by the oxidation reaction shown in the reaction formula '2}, '3}, and a part of it is decomposed by the reaction formula ■, (Thus, it is finally oxidized to sulfuric acid. Day 2S + 03 → Day 20
10S02...t2}Day 2S
+Br2→2HBr+S...
・{31S02 10th 20103 → 2S04 1002
...'4}S04 10th 2011/202
→Sun 2S04...'5} Due to the accumulation of the generated sulfuric acid, the HBr-impregnated carbon packed bed 6 gradually becomes strongly acidic from the air inlet side, and H, which is a weak acid, becomes
Br is replaced with day 2S04 and moved to the exit side, and HBn
It begins to seep out from the adhesive filling layer 6 and leak out. In this state, ozone leaks out significantly. Next, HBr
When the treated gas that has passed through the impregnated coal packed bed 6 passes through the KBn impregnated coal packed bed 8, it first reacts with excess ozone according to equation (6).
'Therefore, 2KBr hydroxide + 03 → day 20 → 2KOH
+Br202...{Produces 6-potassium and bromine.

Potassium hydroxide captures HBr and public ○ by the neutralization reaction formula {nine legs. KOH + HBr → KBr Toka 20
...{7}KOH+Japanese 2S→KHS+
Day 20...[8] Potassium hydroxide further reacts with bromine to form sulfur and is deodorized.

[Reaction formula {9}] KHS+Br2→KBr+HBr1S
...[9} Providing a KBn-impregnated carbon packed bed in this way captures leaked HBr, extending the life of the oxidative deodorizing ability due to the reaction between ozone and HBr, and at the same time increasing the oxidizing ability of hydrogen sulfide. improves.

In this case, if the HBr-impregnated carbon packed bed 6 is not provided and only the KBr-impregnated carbon packed bed 8 is provided, there is no easy Br2 production reaction according to reaction formula (1}, so the initial deodorizing performance will inevitably deteriorate. Finally, the processing gas passes through an activated carbon packed bed to adsorb and remove reaction products such as excess oxidizing agent and sulfur dioxide gas, and is then released as processing air B to the outside of the system.

Although the outline of the structure of this invention is as above, the reaction with malodorous components and effects will be explained in detail below.

Bromides that react with ozone to produce Br2 include H
In addition to Br, there are potassium bromide, sodium bromide, ammonium bromide, magnesium bromide, calcium bromide, etc., but it is HBr that produces bromine particularly efficiently when reacting with ozone, and HBc-impregnated carbon. This invention was completed based on the knowledge that when bromine is used in combination with potassium bromide-impregnated carbon or lucium bromide-impregnated carbon, the reduction in the amount of bromine attached can be suppressed and the oxidizing ability can be maintained for a long time.
Figure 3 is a characteristic diagram showing the removal effect when hydrogen sulfide, a typical malodorous component, is treated. 4 cm of HBn-impregnated coal was filled, and on the other side, 2 c of HBr-impregnated coal of the same particle size was first filled, and on top of that, a total of 4 skins of 2 cm of KBr-impregnated coal of the same particle size were filled, hydrogen sulfide was 30 ppm, ozone was 30
This is a characteristic diagram showing the change over time in the removal rate of hydrogen sulfide when the air to be treated containing ppm is aerated at 10 so/min for 5 times.Characteristic curve A is the characteristic curve when only HBG-impregnated coal is charged. B shows the case where HBr-impregnated coal and KBr-impregnated coal were filled.

The combination of HBr-impregnated coal and KBr-impregnated coal was more effective.After conducting the above test, air containing 3 ppm methyl sulfide and 30 ppm ozone was vented into each packed bed for 1 hour. As a result of investigating the removal efficiency of methyl sulfide, the removal rate was 99% or more in all cases, and it was confirmed that the original removal ability was not decreased. Figure 4 shows the results of investigating the relationship between the packed bed thickness from the treated gas inlet side of the impregnated coal used in these experiments and the bromine impregnation rate. HBr-impregnated carbon contains approximately 0.8 in terms of bromine.
4% HBr, 0.755% KBr for KBr impregnated coal
Impregnated charcoal was used. The characteristic curve C shown by the solid line in the figure is the result when the carbon is filled with f-bar impregnated coal, and the characteristic curve D shown by the broken line is the result when the carbon is filled with 2 cm of HBr-impregnated coal and then 2 cm of KBr-impregnated coal. In the former case, the bromine impregnation rate decreased from 0.84% to 0.8-0.81%, but in the latter case, it decreased similarly in the HBG-impregnated coal part.
The bromine impregnation rate at the inlet of the KBr-impregnated coal increased to 0.85%, and the pH decreased. This is thought to be because HBr released from the HBr-impregnated coal packed bed is adsorbed and retained in the KBr-impregnated coal layer according to reaction equations (6}, '7}. In other words, the movement of HBr is apparently blocked. ,
This is thought to be because HBr moves more slowly than in the case of HBr-impregnated coal alone. In this example, the case where activated carbon was used as the carrier was explained, but carriers such as activated clay, silica, alumina, alumina, etc. may also be used. The HBr-impregnated bodies used in these Examples were prepared by soaking each carrier in a 10% hydrobromic acid aqueous solution for 1 hour and then drying it in a nitrogen gas atmosphere.

The vapor pressure of 10% hydrobromic acid is as low as 4 x 10-4 Hg, and there is almost no irritating odor, so it is easy to handle, and less hydrogen bromide is released during drying with nitrogen gas.

However, when a hydrobromic acid impregnated body is prepared using an aqueous solution of 30% or more, hydrogen bromide is significantly released as a result of drying, which is not economical. When using a 10% aqueous solution of hydrobromic acid, the amount of impregnated onto various carriers is expressed as weight % per unit weight of each carrier and expressed in terms of bromine: activated carbon 0.8 to 1.5%, activated clay 4. 8-5%, alumina 2
．． It was 5-3%.

. As described above, it is preferable to use a 10% hydrobromic acid aqueous solution to prepare the impregnated carbon, but there is no practical problem even if a 2% solution is used.

Note that the impregnated body prepared in this way is also impregnated with hydrobromic acid and hydrogen bromide, and even if a gas containing hydrogen bromide is passed through the impregnated body instead of using an aqueous solution of hydrobromic acid, the same impregnated body will not be produced. was gotten.

In addition, KBr-impregnated coal should be 1.5% or less (
It was prepared by the same treatment as the HBG-impregnated carbon using a KBr aqueous solution (2% to 15%).

The appropriate amount of KBr impregnated was 0.5% to 5% in terms of bromine. Here, the case of KBr-impregnated coal was shown, but NaBr,
Similar effects are also exhibited by bromides of alkali metals and alkaline earth metals such as CaBr2 and MgBr2. In addition, as an example of the deodorizing device, we have explained the case where activated carbon is used in the final packed bed of the reaction tower, but hydroxides or carbonates of alkali metals or alkali metals are impregnated with a carrier such as activated carbon, zeolite, or alumina. An impregnated body capable of removing excess oxidizing agent and reaction product sulfur dioxide gas such as KI-impregnated carbon may be used if economically permitted.

As explained in detail above, the present invention comprises an ozonizer, a device for aerating ozonized air supplied from the ozonizer into air to be treated containing malodorous components, and hydrogen bromide or hydrobromic acid as a carrier. A packed bed of an impregnating body to be impregnated, a packed bed of an impregnating body to impregnate a carrier with an alkali metal or alkali metal bromide, a packed bed of activated carbon or an alkali impregnating body, and a packed bed of an impregnating body to impregnate the carrier, and a packed bed of an impregnating body to impregnate the support with the ozone-added air. Above HB
It is equipped with an air supply device that passes through the r impregnator layer, the KBr impregnator layer, and the activated carbon packed bed in this order, and oxidizes malodorous components with bromine produced by the reaction of ozone and hydrogen bromide or hydrobromic acid. Therefore, components such as ammonia, methyl sulfide, and methyl disulfide, which are difficult to adsorb and remove with activated carbon, can be efficiently removed.Also, by passing through the KBh impregnator layer, HBr leaking from the HBr impregnate layer is captured. death,
In order to effectively utilize this, the life of the oxidation reaction using ozone and HBr will be extended, and the efficiency of removing hydrogen sulfide will be increased.

Furthermore, since excess oxidizing agent and reaction products are adsorbed and removed by the packed bed of activated carbon or alkali impregnated material, no secondary pollution occurs. Brief Description of the Drawings Fig. 1 is a flow diagram of a conventional dry deodorizing device using ozone, Fig. 2 is a flow diagram showing an embodiment of the present invention, and Fig. 3 is a flow diagram of a conventional dry deodorizing device using ozone.
FIG. 4 is a characteristic diagram showing the hydrogen sulfide removal effect in a packed bed combined with Br-impregnated carbon, and FIG. 4 is a characteristic diagram showing the layer thickness dependence of the bromine impregnation rate according to the present invention.

In the figure, 1 is a blower, 3 is an ozonizer, 4 is a mixed layer, 6 is a reaction column, 6 is an HB-enhanced carbon packed bed, 7 is an activated carbon packed bed, and 8 is a KBr-impregnated carbon packed bed. Note that the same reference numerals in the figures indicate the same or corresponding parts. Figure 1 Figure 2 Figure 3 Figure 4

Claims (1)

[Claims] 1. An ozonizer, a means for mixing the ozonized gas supplied from the ozonizer with the air to be treated containing malodorous components, and an impregnator for impregnating hydrogen bromide or hydrobromic acid onto a carrier. a packed bed of an impregnator for impregnating an alkali metal or alkaline earth metal bromide onto a carrier; a packed bed of activated carbon or an alkali impregnator; A dry deodorizing device comprising an air supply device that passes through a hydrobromic acid impregnated layer, a bromide impregnated layer, and an activated carbon packed bed in this order. 2. The dry deodorizing device according to claim 1, wherein the carrier is activated carbon, zeolite, silica, alumina, or alumina. 3. The dry deodorizing apparatus according to claim 1, wherein the amount of hydrogen bromide or hydrobromic acid impregnated is within the range of 0.1 to 10% by weight in terms of bromine. 4. The dry deodorizing device according to claim 3, wherein the amount of hydrogen bromide or hydrobromic acid impregnated is within the range of 0.5 to 5% by weight in terms of bromine. 5. The dry deodorizing device according to claim 1, wherein the amount of alkali metal or alkaline earth metal bromide impregnated is within the range of 0.1 to 10% by weight. 6. The dry deodorizing device according to claim 5, wherein the amount of the alkali metal or alkaline earth metal bromide impregnated body is within the range of 0.5 to 5% by weight.