JPS59196716A - Adsorption and desorption of organic gas - Google Patents

Abstract

PURPOSE:To prevent the deterioration of an adsorbent caused by the decomposition and polycondensation of a residual polar solvent, by using an inorg. adsorbent to which a liquid phase is preliminarily adhered while desorbing the org. gas adsorbed therewith by microwave dielectric heating. CONSTITUTION:The chemical characteristics possessed by an adsorbent is almost removed by using an adsorbent (adhering adsorbent) wherein a liquid phase is preliminarily adhered to 0.5-60% of the pore volume thereof and the temp. control of the adhering adsorbent in a desorbing tube is achieved by controlling microwave power by using the temp. of desorbed gas and/or the temp. of carrer gas in the tube approximate to an desorbing temp. as indice because coefficient of heat conductivity of the carrier gas and the filled adsorbent moved through the desorbing tube. In addition, as the liquid phase of the adhering adsorbent, alkylene glycohl phthalic ester is used with alcohol and polyalkylene glycol with ketone.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for stratifying an organic gas.

The hexavalent gases are absorbed using adsorbents such as activated carbon, alumina, zeolite, and silica gel, and then desorbed by inert gas and water vapor. Organic gas refers to hydrophobic organic gas and tree-philic EJ' 4G gas.

The drawback is that the recovery cost of separating the hydrophilic organic gas (hereinafter referred to as polar solvent) from water is high. When using inert gas, the gas temperature is small and Otani? Although it is possible to supply the dequenching energy only by flowing +t of heated gas, there is a drawback that the recovery cost is high due to the waste energy consumption.

The organic gas (dissolved (in the form of sand)) in the pores is heated by microwave dielectric heating on the adsorbent that has adsorbed the organic gas, and it can easily be heated to high temperatures without contact with a heat medium such as steam. It is known that it is possible to desorb a high concentration of IA mechanical gas. [Barachir Kolonges Research Institute Chem & News
-USAP 23, June 21 (1982
)) When a polar solvent is mixed with water vapor, the amount of water vapor adsorbed by the inorganic adsorbent may reach two to several times that of the polar solvent. Mix or dissolve, making it impossible to reuse the recovered polar solvent as is. The mixed gas of water vapor and polar solvent is passed through an inorganic adsorbent that selectively adsorbs only water vapor, and after removing the water vapor, the remaining polar solvent is removed by another inorganic adsorbent. Although it is possible to recover a polar solvent that does not contain water by separately heating the two adsorbents with microwave dielectrics and desorbing them separately, this requires additional equipment and processing costs to remove water vapor.

The desorption time using microwave dielectric heating is 1 to 1 Klo minutes compared to 11 Klo minutes when desorption is performed using heating with a heat medium.
The desorption time is only 0 minutes, the scale of the desorption tube is as small as 0 to 100000 minutes, and the energy consumption is reduced by more than 10% compared to thermal desorption using a heat medium.

Inorganic adsorbents include alumina, silica gel, silica
Tree friends refer to alumina glue, activated bokite, synthetic and natural zeolites, and activated clay. Inorganic adsorbents have a low dielectric constant and are difficult to heat, but polar solvents adsorbed in the holes have a low dielectric constant and easily generate heat, so they have the advantage of being able to be desorbed at high concentrations.

Ti-based solvents include alcohols, hydroxyaromatic compounds, chthons, ethers, aldehydes, esters, halogenated hydrocarbons, halogenated aromatic solvents, and aromatic polar solvents that are inorganic.
1j, when adsorbed by a flattening agent (hereinafter referred to as an oil-absorbing agent),
The chemical affinity between the two is large, and the polar solvent is adsorbed and retained on the surface of the adsorbent, and remains without being desorbed even when the temperature is raised above the predetermined point by microwave dielectric heating. The remaining +11 polar solvent 'M does not reach more than 30% of the adsorbed amount. Furthermore, microwave dielectric heating of the residual polar solvent causes partial decomposition or polycondensation, resulting in a disadvantage that the per-capacity performance eventually decreases to less than 1%.

In the dark room under the aquarium! , Manufacture 1 The present invention retains the property of being able to directly desorb and recover high-concentration organic gases from the adsorbent using microwave dielectric heating, and eliminates the disadvantage of not being able to concentrate residual organic gases. To provide a method for separating and recovering component gases from a multicomponent mixed gas at the same time as desorption at a facility scale of 1/2 to 10 times the size of a steam desorption cylinder, and preventing deterioration of adsorbent due to decomposition and polycondensation of residual polar solvents. It is something.

By using an adsorbent to which 0.5 to 60% of the pore volume of the liquid phase is attached in advance (hereinafter referred to as an attached adsorbent), the chemical properties of the adsorbent are almost completely eliminated. I can do it.

If the amount of liquid phase adhesion reaches 60% or more, the absorption rate will decrease, 05
If the chemical properties of the adsorbent are eliminated, L! : I can't do it. Generally, 1-10 yen is desirable. When a polar solvent is adsorbed onto an adsorbent to which no liquid phase is attached and desorbed by microwave dielectric heating at the boiling point of the polar solvent of 10 to 5 degrees Celsius, most of the polar solvents will be absorbed at 5 to 30 degrees Celsius of the adsorbed amount. % remains.

It has been discovered that by adsorbing this polar solvent onto an adsorbent and heating it with microwave dielectric heating, the amount of remaining solvent can be reduced to almost zero. For polar solvents, such as cyclohexanone, where the amount of residual adsorption increases as the number of desorptions increases,
A residual adsorption Ji) of 60% can be reached by simply repeating the operation of adsorbing to an adsorbent to which no liquid phase adheres and desorbing by microwave dielectric heating several times.

On the other hand, using an adhesive adsorbent with polyethylene glycol (PEG) as the liquid phase, the residual adsorption of cyclohexanone can be suppressed to zero even after one pumping and desorption of cyclohexanone is repeated dozens of times in the same manner as above. Moving bed type adsorption/desorption device i″IV
(The desorption tube is provided under the adsorption layer, and the adsorbent moves downward from the adsorption layer to the desorption tube.) In the desorption tube I''i, a plurality of magnetic desorption tubes are arranged vertically, and the adsorbent moves downward from the adsorption layer to the desorption tube. The 1 pump and 1 drug move down the desorption tube.The lower part of the desorption tube is used as a decoupling layer, and the upper part is used as a rectification layer.Microwave irradiation is applied from outside the desorption tube.
The attached IJ moving inside the pipe desorbs the organic gas adsorbed to the adhesive. The residence time of the adsorbent adsorbent moving in the desorption tube in the desorption layer is the removal time.

During desorption, a carrier gas is introduced into the desorption tube at S■=0.
By supplying at 1 to +000 (i), it became easy to take out the desorbed organic gas out of the system. However, in the case of continuous desorption without passing through the carrier gas, the carrier gas is not necessarily required because the subsequent desorption gas pushes out the desorption gas that was desorbed earlier toward the second piston.

Since the heat transfer coefficient between the carrier gas and the adsorbent filling and moving in the desorption tube is large, temperature control of the adsorbent adhering in the desorption tube is performed by controlling the temperature of the desorption gas in the tube close to the desorption temperature and/or
This can be achieved by controlling the microwave power using the temperature of the carrier gas as an index.

When two or more polar solvents with different boiling points adsorbed on an adsorbent are desorbed and extruded with a carrier gas, the liquid phase of the adsorbent acts as a distributing agent, and microwave irradiation directly removes the polar solvent. Because the temperature is raised, there is no temperature difference between the tube wall and the center shaft of the tube, even if the tube diameter is larger than when heating the outside of the tube with a heating medium, and complete desorption is possible in a short time of 1 to several minutes after breaking. Since it is possible to do so, the detachable tube can be made smaller, and the diameter of the tube can be reduced to a length of 0.5 meters. If the tube is long, a rectification effect will be produced in the upper layer, and the number of theoretical plates can be increased. The adsorbent that moves at a steady rate in the pipe is 5
The desorption gas is developed in the fine glaze layer by the carrier gas and the desorption gas of V=0.5 to 1000 (soldering).Differences in movement speed occur due to the difference in solubility of each polar solvent in the liquid phase. It has now become possible to completely separate the components into their components on an industrial scale.

The separated and developed polar solvent is arranged in layers from the upper layer to the lower layer of the rectification layer, from low boiling point to high boiling point polar solvent.
By discharging and condensing the desorption gas for each layer, it is possible to selectively recover the polar solvent into its components with thermal efficiency.

If the carrier gas is less than 5V=0.5 (4), the desorption gas cannot be completely discharged to the outside of the yarn. 5V=1000(i)
If the amount exceeds 100%, the facility for cooling the desorbed gas will become large and uneconomical. To separate mixed gas into component side, 5V = 5~2
00 (Maki) is commonly used.

If an adsorbent is not used, the adsorbed mixed polar solvent cannot be stratified into components in the rectification layer, so it is discharged from the desorption column as a mixed gas! :become.

Even when mixing hydrophobic organic gases, using an adhesion adsorbent can improve the separation performance of each component without adhering the liquid phase.
Since it is 3 to IO times higher than the l agent, the desorption cylinder,
The size of the rectifying layer can be reduced to 14 to 1°.

In fixed-bed two-batch desorption systems, the separation performance in the rectifying layer governs the separation of the mixed gas. Even if the gas is a mixture of water vapor and a polar solvent, there is no need to selectively adsorb and remove water vapor in advance.

For example, 1.2% of Fluorolube HG-] 200 (Shinsou Kako KK) was adhered onto 4 to 8 mesh grains of alumina gel, and 5.4% of P, E, G, molecular weight 1000 was added.
After a mixed gas of methanol and water is adsorbed onto the attached adsorbent, it is transferred to a desorption cylinder having a plurality of adsorption tubes arranged vertically.

Desorption is performed by irradiating microwaves from the outside of a magnetic desorption tube (diameter 25w x 1°5m) and dielectrically heating it. A carrier gas (Nz
) is passed from the bottom of the tube at 5V=lO(i), and the rectification layer is 68~
At 70°C, the desorption layer was maintained at 98-+03°C.

Methanol is desorbed within 3 to 5 minutes after passing the carrier gas, and water is desorbed after 3 minutes, resulting in fractional recovery.

The liquid phase of the adsorbent has the following characteristics.

■Me Re
ynolds Con5tant (J, Chroma
togr, SCi 8685 (1977)': One example will be given regarding the liquid phase of an adhering adsorbent with a high l value (strong polarity) for a polar solvent.

1 to alcohol. Alkylene glycol phthalate ester, alkyl fucurate ester, polyalkylene glycol, alkyl (Cs or higher) alcohol ester, alkyl (08 or higher) amine, alkylene diamine,
Six → xypolyalkylene glycol.

Polyalkylene glycol, polyoxyalkylene fatty acid ester, aldehyde, polyalkylene glycol, +dexypolyalgylene glycol, alkylene glycol fatty acid ester, polyoxyalkylene fatty acid ester, amine/and, alkyl amine , alkylene amine, polyalkylene glycol, alkylene diamine alkylene glycol fatty acid ester, alkylene glycol phthalate ester, for organic acids, alkylene glycol phthalate ester (AGPE), polyoxyalkylene fatty acid ester, polyalkylene glycol, AGPE+H3PO4,
For alkylene silicone polymer ester, polyalkylene glycol, dialkylene glycol, dialkylene glycol fatty i1 ester, alkylphthalic acid, AGPE, for alkylene glycoxyketo acid, AGPE+H3PO4,
For polyoxyalkylene fatty acid ester phosphate, halogen compounds, fluororesin oil, silicone oil, AGPE, polyoxyalkylene fatty acid ester hydrous polar solvent, fluororesin oil, acrylic resin type ester, hydrophobic organic gas On the other hand, if the following liquid phase is used, the separation efficiency of the mixed gas will be improved and residual hydrophobic organic gas will be eliminated.

For hydrocarbons, silicone oil, polyalkylene glycol, dialkyl phthalate ester, trialkyl fucurate ester, dialkylene glycol, statholane, for aromatic hydrocarbons, benzoquinone, polyphenyl ether or more. The combination of liquid phase and adsorbent must be selected depending on the type of polar bath agent.

The present invention will be explained in detail with reference to Examples.

Example-1 Inorganic adsorbent Water-resistant silica gel (chemical composition A12031
2chi, 5F0288%, Na2O0'i6 porosity 0.
51 apparent specific gravity 1.1) alumina (chemical composition AJ2038
8%, 5i029, Na2O3%, porosity 0.7 apparent specific gravity 1.0) K liquid phase PE, G (3.7% each of molecular weight 400 attached). , cyclohexanone acetate ethyl ester at 20℃
Microwave irradiation after equilibrium adsorption (the magnetron that generates microwaves has a frequency of 2450 ± 50 MHz and an output of 5 k'
W) L, desorbed by dielectric heating. The microwave irradiation time was 6 minutes, and the desorption temperature was cyclohexanone 156.
~158°C and ethyl acetate 78°C.

Adsorption and degreasing - adsorption rates for #, 1st and 6th times, and solvent residual rate after desorption are shown in Table 1.

Margin table below - 1 The residual rate of the adsorbent to which no liquid phase adheres is higher than that of the adherent adsorbent, and for both cyclohexanone and acetic acid ethyl ester, the residual rate increases as the number of desorptions increases, and the 6th adsorption 4! - is larger for the adhered V adhesive.

Example-2 Inorganic adsorbent alumina (chemical composition Al2O390%5i
0210% No200% Porosity 0.71 Apparent ratio Wj 0
．． 9) A polar solvent, butyl acetate, cyclohexanone, 2-hexanol, and crotonaldehyde were each adsorbed on the adsorbent to which K 4.4% liquid phase polypropylene glycol (PPG-'1025)' was attached, and the same as the above alumina was used. Polar solvents were treated in the same way (B)
, water resistance', silica gel (chemical composition AI! 20311%
5i0289% Na2O0% Apparent specific gravity 1.3 Porosity 0.
41) Polar solvents butyl acetate, cyclohexanone, crotonaldehyde, and 2-hexanol were adsorbed on the adsorbent adsorbed with 4.8% K 4.8% liquid phase ethylene glycol heptatarate (EGPE) (C),
For (D), (5), (B), (C), and (D) in which water-resistant silica gel was treated with the above polar solvent in the same manner, it was desorbed by microwave dielectric heating.

The dielectric heating time was 6 minutes, during which time 5V = 5 was applied with N2 gas.
Table 2 shows the residual adsorption rate when adsorption and desorption are repeated 6 times with the desorption gas temperature maintained at 127°C for butyl acetate, 156°C for cyclohexanone, 140°C for 2-hexanol, and 105°C for crotonaldehyde. It shows.

Magnetron has frequency &2450±50 MHz output 5
used punishment.

Table 2 The adsorption rate of each polar solvent on the adsorbent is the 1st and 6th adsorption rate.
There is no difference the second time. On the other hand, the adsorption rate decreased and the residual rate was large except for eye patch 2 hexanol.

Example-3 Liquid phase diethylene glycol succinate (DEGS) was added to the inorganic adsorbent silica-alumina gel (S-A) (chemical composition: 5iOz 51%, Al2O3 45%Fg2034%, porosity 0.4, apparent specific gravity 1.0). 4.4% was attached, ethyl propionate was adsorbed, 5.8% of liquid phase polyphenyl ether (PPE 6 rings) was attached to S-A, m
-Liquid phase silicone oil (DC) adsorbs xylene to SA
-200 Shinwa Kako KK) was deposited at 38% to adsorb trichloroethane, and S-AKEGPE 4.2%
+H3PO40.2% attached, adsorbs phenol and activates bauxite (chemical composition 5i0223%AI!203
60% Fe2O3 17% Porosity 0.42 Apparent specific gravity 1.9
) was attached to 3.5% PPE to adsorb xylene. The adhered adsorbent adsorbed with the polar solvent was irradiated with microwaves for 6 minutes and desorbed by dielectric heating. A carrier gas (N2) was fed into the desorption tube at SV-+0 (-!-), and the gas temperature inside the tube was maintained at +1 to 3° C. above the boiling point of each polar solvent. The removal temperature of each polar solvent is shown in Table 3. The same adsorption/desorption operations were performed using the same polar solvent for adsorbent S-A, which does not adhere to liquid, and activated bauxite, and the adsorption and desorption rates are shown in Table 3.

The magnetron has a frequency of 12450 ± 50 mechahertz output 5
KW was used.

Table-3 Indicates the east desorption temperature.

There is no difference in the adsorption rate between the first and sixth times for the adhered adsorbent. On the other hand, with the exception of m-xylene, the adsorption rate of adsorbents decreases and the residual rate is large.

Example-4 Adsorbent, Sumitomo Alumina DT (chemical composition Aj'20310
0chi, porosity 0.57 apparent specific gravity 1.3) S 1IJ
JI K liquid phase polyoxyethylene sorbicne ester (
Attach PO5E) 4.8% and H3PO40.25%,
A mixed gas of acetic acid (110-1501%), butyric acid (30-351%), and air was treated with a moving bed adsorption/desorption device to separate and recover acetic acid and butyric acid. The adsorption/desorption device is equipped with a desorption tube below the adsorption layer, and the desorption tube consists of a plurality of magnetic desorption tubes (25
Mil x 2m) are arranged vertically, and each desorption tube has a 30m bottom section.
The layer above is the desorption layer, and the layer above it is the rectification layer. The top layer of each rectification layer was irradiated with microwaves from outside the 30cm1i tube.
It was maintained at 6°C. N heated to 160℃ from the bottom of the desorption tube
Two gases were blown at 5V=5(4), and microwave irradiation was applied from outside the tube of the 30 ports of the desorption layer to control the temperature of the 30 ports of the desorption layer to 165°C. The desorption time was 8 minutes.

A discharge port was provided to discharge acetic acid from the upper layer of the rectifying membrane and butyric acid from the lower layer of the rectifying membrane, and the deionized adsorbent was constantly collected from the bottom of the desorption column. Each sil-1. ．． Table 4 shows the composition of the de-stone gas at the lj port and the acid remaining in the desorbed A9 suction gas.

The magnetron used was a frequency 24 s o ±50 MHz output SKW.

Table-4 that's all

Claims (1)

[Claims] l) When an adsorbent adsorbs and desorbs an organic gas, an inorganic adsorbent to which a liquid phase has been attached in advance is used, and the adsorbed organic gas is desorbed by microwave dielectric heating. 2) An organic gas adsorption/desorption method characterized by the following: 2) The amount of liquid phase to which the inorganic adsorbent is attached is 0.0% of the pore volume.
3) Organic gas adsorption/desorption method as described in item 1, characterized in that the organic gas is adsorbed by microwave dielectric heating. =0.
5 to 1000 (-) When a carrier gas is passed through the organic gas adsorption/desorption method described in Section 4), when desorbing a mixed organic gas from an adsorbed adsorbent, The organic gas adsorption/desorption method described in item 1, wherein a rectification layer is provided on the desorption tube and the desorption gas is separated into each component gas by the rectification layer.