JPS5839577B2 - Cutlet Seitan No Saiseihou - Google Patents

Description

[Detailed description of the invention] Ozone has a unique oxidizing ability, so it can be used for deodorization, decolorization, etc.
It is also effectively used in water treatment, etc., but due to the low solubility of ozone in water, unreacted gases may be released into the atmosphere and cause secondary pollution, so waste ozone gas is contacted with activated carbon, etc. It is necessary to prevent the damage by disassembling it.

However, since expensive activated carbon is used in the catalytic cracking operation, when considering the possibility of recycling from an economic standpoint, the following recycling methods are considered: water washing, chemical washing, heating, steam heating, etc. Although attempts were made to regenerate the material by washing with water, it was thought that a heating method (air heating method) would be the most appropriate, so the following questions were asked: (1) Is it possible to regenerate at low temperatures?

(2) What conditions are sufficient for the reproduction rate?

(3) How much is the activated carbon consumed at that time?

(4) Is it possible to use it repeatedly?

We conducted experiments on the following. In conventional water treatment, activated carbon, which has been used to catalytically decompose organic substances in water, is
The regeneration process is carried out at a high temperature around ℃, but this is because when the amount of oxygen mixed in is reduced to reduce consumption of the activated carbon, some of the organic pollutants are carbonized and remain on the activated carbon, and this charcoal is heated to a high temperature. This is because it is believed that if activated carbon is not activated, activated carbon will not be regenerated.

On the other hand, in the activated carbon to be regenerated in the present invention, the gas to be catalytically cracked is air containing ozone, and since there is no organic washing substance contained in water, the activated carbon cannot be treated at high temperatures as described above. There is no need to carry out this process; all that is needed is to remove the ozone and the product residue formed on the surface of the activated carbon.

In the contact reaction between ozone and activated carbon, cracks occur in the activated carbon due to the cleavage of the C>C-0) double bond, and if the activated carbon is regenerated by heating at a high temperature of around 800°C,
Although it is possible to recover the performance, the charcoal grains will become tattered and
It cannot maintain its original form.

In order to suppress this phenomenon, we performed low-temperature heating, checked the regeneration ability, and compared it with unused coal.We found satisfactory results, and in some cases, the catalytic cracking capacity increased even more than unused coal. It was also found that

Next, the situation will be explained using an example.

First, a certain volume of 30 ml of activated carbon that has reached saturation by catalytically decomposing the moist ozone gas that has come out through water is collected and heated in an electric furnace. Catalytic cracking of ditheosin was carried out at a flow rate of 3 J/min at a flow rate of 3 J/min of waste, and the catalytic cracking breakthrough curves were created and compared while checking the outlet concentration of the catalytic cracking apparatus, and the results shown in Figure 1 were obtained.

In other words, the experimental results show that even if heated for a long time at a heating temperature of 100°C, the catalytic cracking power hardly recovers and the
The catalytic cracking power has recovered from ℃.

At 300°C, the catalytic cracking ability was recovered to approximately the level of unused coal after 20 minutes of heating.

Looking at FIG. 1, it can be seen that in this experiment, activated carbon treated at 300° C. for 20 minutes sometimes showed better performance than virgin carbon around 5 hours after the start of catalytic cracking.

In order to investigate the changes in catalytic cracking force and attrition rate due to repeated reuse, activated carbon was used under the best conditions.
℃ for 20 minutes in an electric furnace, and an ozone gas removal test was conducted under the same conditions. Due to the deterioration of the activated carbon, the ozone scum outlet concentration was 0. Figure 2 compares the time required for deterioration when IVolp, p, and m are reached and the state of ozone gas catalytic decomposition per unit weight of activated carbon.

In addition, regarding the change in the wear rate, the drying conditions of the sample were kept constant and the test was conducted according to the waterworks stream sand test method.
The results shown in the table below were obtained.

In this test method, the particles are first passed through a crusher and then sieved, and the strength of the particles decreases when the ozone is catalytically decomposed.

The changes during repeated use due to air heating regeneration are as described above, but when considering the deterioration of the strength of activated carbon, it seems that when used as is, the limit is 3 uses due to 2 regenerations.

Although an issue with treating ozone with activated carbon is the explosion phenomenon, no explosion was observed when low-concentration wet ozone gas was brought into contact, so this point should be taken into account when designing the equipment. Should.

To summarize the above, the method of the present invention: (1) Regeneration can be performed at a lower temperature of 200°C to 300°C compared to the conventional regeneration temperature of 800°C to 1000°C.

(2) Since it is regenerated at low temperature, activated carbon is less consumed even if oxygen-containing gas is mixed in.

(3) Although there are some cases where the catalytic cracking capacity is greater than that of unused coal, the recovery of the catalytic cracking capacity is generally good.

(4) When heating at around 300°C, the treatment can be done in a very short time.

[Brief explanation of the drawing]

In the attached Vfff drawing, Figure 1 is a chart showing the recovery of catalytic cracking capacity by heating regeneration, and the ozone concentration is 4.5P/m.
, I is 2 under the conditions of activated carbon amount 3Qmg and gas flow rate 31/min.
00℃ 1 hour, ■ 200℃ 3 hours, ■ 300℃ 10
(2) shows the catalytic cracking breakthrough curve of unused coal. Figure 2 is a chart showing changes in the amount of catalytic decomposition due to repeated regeneration, and shows the ozone concentration of 2'iI/m' and the amount of activated carbon of 105 after heat regeneration at 300°C for 20 minutes.
m11 gas air volume 7. Ol: 300℃2 for 7 minutes
The graph shows the catalytic cracking ability curves after 0 minutes of heating regeneration, where 0 is unused coal, 1 is once regenerated coal, 2 is twice regenerated coal, and 3 is three times regenerated coal.

Claims (1)

[Claims] 1 In the thermal regeneration treatment method for activated carbon, activated carbon whose ability to catalytically react wet ozone gas has deteriorated and undecomposed ozone gas can be detected is heated to 200°C to 300°C.
A method for regenerating activated carbon, the method comprising performing heat treatment at a temperature of 10 minutes to 1 hour.