JP2009195820A - Technique of preventing leak of methyl acetylene or propadiene - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for preventing rapid leak of methyl acetylene or propadiene and also a gas storage apparatus in which the apparatus for preventing the rapid leak is built in. <P>SOLUTION: Air containing methyl acetylene (hereinafter, abbreviated as MA) or propadiene (hereinafter, abbreviated as PD) is brought into contact with an adsorbent capable of adsorbing 5 wt.% or more of MA or PD, in an MA or PD adsorption method. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention relates to an adsorption technique for methylacetylene (hereinafter abbreviated as MA) or propadiene (hereinafter abbreviated as PD), and leakage of MA or PD can be achieved by using a compound capable of adsorbing MA or PD. It is characterized by enabling prevention or suppression.

C3 and C4 unsaturated hydrocarbons are important compounds as raw materials for various petrochemical industries. So far, the materials used as the main raw materials of general-purpose polymers such as propylene and butenes have characteristic properties as these adsorbents, and effective separation and purification and storage. It is reported that it contributes to (refer patent documents 1-3).

On the other hand, with the development of new reactions and applications, MA and PD are also becoming more useful as industrial raw materials. MA and PD are generally stored as liquefied gas, but both MA and PD are compounds that can potentially cause a combustion explosion or decomposition explosion (see Non-Patent Document 1), so that they are safer to store. Is required.

As a method for enhancing safety, storage at low temperature is effective, but the boiling points of MA and PD are each -20 ° C. or lower, and cooling to sufficiently lower the vapor pressure requires a large energy cost. Moreover, in the method limited to temperature control, when the storage device is damaged, there is a risk that sudden leakage occurs and it cannot prevent a serious accident.

As a method for preventing rapid leakage, a method using any adsorbent capable of adsorbing MA or PD at a low pressure is conceivable. As an adsorbent for leakage prevention, a compound capable of adsorbing low-pressure MA or PD is preferred, but there has been no example of evaluating the adsorption / desorption behavior of low-pressure MA or PD so far. It cannot be said that it has been done.
WO2002058820 US2005096494 US20040260138A1 Tetsuzo Kitagawa et al., Safety Engineering 1967, 6, 213-220

An object of the present invention is to find an adsorbent that can adsorb MA or PD in a temperature range that can be cooled at low cost and that is difficult to desorb. Another object of the present invention is to provide a device for preventing MA or PD from suddenly leaking by using the corresponding compound and a gas storage device incorporating a device for preventing sudden leakage.

The present inventors diligently studied to solve the above-mentioned problems, found an adsorbent capable of adsorbing MA or PD in a large amount, and reached the present invention.

That is, the present invention provides a method for adsorbing MA or PD, which comprises contacting a gas containing MA or PD with an adsorbent capable of adsorbing 5 wt% or more of MA or PD.

The present invention provides a new technique for preventing MA and PD from suddenly leaking. With this technology, it is possible to improve safety and reduce energy costs during storage of MA and PD.

The gas containing MA or PD used in the present invention is not limited as long as it is a gas containing 1 wt% or more of MA or PD, but is preferably a gas containing 10 wt% or more of MA or PD, more preferably Is a gas containing 90 wt% or more of MA or PD.

If the adsorbent used in the present invention is an adsorbent capable of adsorbing 5 wt% or more of MA or PD, whether the material is an organic compound, an inorganic compound, an organic-inorganic hybrid compound, or a mixture thereof. Regardless, the mode of the adsorbent may be crystalline or amorphous, but in order to suppress an increase in the size of the apparatus, it is preferable that the adsorbable amount is large.

Examples of the organic compound used as the adsorbent include crystalline or amorphous organic polymer compounds.

Examples of inorganic compounds used as the adsorbent include zeolite, silicalite, mesoporous silica, activated alumina, silica gel, porous glass, activated carbon, molecular sieve carbon, carbon nanotube, carbon nanohorn, and the like.

Examples of organic-inorganic hybrid compounds used as adsorbents include metal complexes, inorganic porous compounds linked to organic compounds and metal complexes via bonds, and inorganic compounds and metal complexes linked via bonds. Examples thereof include organic porous compounds, carbon nanotubes linked to inorganic compounds and metal complexes via bonds, and carbon nanohorns linked to inorganic compounds and metal complexes via bonds.

Preferred adsorbents include compounds having pores with a pore diameter in the range of 0.35 nm to 1 nm, zeolite, silicalite, activated alumina and the like. More preferably, zeolite having pores having a pore path diameter in the range of 0.35 nm to 1 nm, more preferably zeolite A excluding zeolite 3A, and most preferably zeolite 4A. Zeolite A, zeolite 3A, and zeolite 4A are described in Japanese Patent Publication No. 2891493. The pure zeolite 4A can be represented by a composition ratio of sodium oxide (Na ₂ O), silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), and water, and the zeolite used in the present invention. In 4A, 10% or less of sodium ions may be replaced with protons or other metal cations. There are no restrictions on the element of the metal cation replacing the sodium ion, but lithium, potassium, rubidium, cesium, magnesium, calcium, strontium, barium, etc. are included, and one or more of these are included. Also good. When the metal cation to be replaced is a divalent cation, one divalent cation is replaced for every two sodium ions. From the viewpoint of volumetric efficiency, it is desirable to avoid mixing in compounds with a small amount of MA or PD that can be adsorbed, but it may be more preferable to mix and use a substance with a poor amount of adsorbable for purposes such as molding. .

Further, the adsorbent used may be capable of adsorbing 5 wt% or more of MA or PD under arbitrary conditions, but it is desirable that the amount of adsorption of MA or PD is large even in a state where the partial pressure of MA or PD is low. For example, an adsorbent that adsorbs 5 wt% or more of MA or PD when the partial pressure of MA or PD is brought into contact with a gas of 0.05 bar or less is preferable. Further, an adsorbent that adsorbs 5 wt% or more of MA or PD when the partial pressure of MA or PD is brought into contact with a gas of 0.01 bar or less is more preferable.

Regarding the release characteristics of the adsorbed gas, it is desirable that it is difficult to release. When MA or PD is adsorbed at a certain pressure and then the partial pressure of MA or PD is lowered to 0.01 bar, 5 wt% or more of MA or PD is preferably adsorbed.

Generally, the amount of gas adsorption increases as the temperature decreases. From this, it is easily inferred that an adsorbent exhibiting sufficient adsorption ability at high temperatures can exhibit sufficient adsorption ability even at low temperatures. That is, a compound that exhibits a sufficient amount of adsorption at a higher temperature is considered preferable.

Adsorbent that can achieve MA or PD adsorption of 5 wt% or more at −15 ° C. when it is brought into contact with a gas having a partial pressure of MA or PD of 0.01 bar or less when aiming at operation with an inexpensive cooling facility. Is preferred. More preferred is an adsorbent that can be achieved at −5 ° C., and even more preferred is an adsorbent that can be achieved at 25 ° C.

Next, an apparatus for preventing MA or PD leakage or reducing the leakage speed using the above invention will be described. The apparatus using MA or PD is made into a double structure, and the space between the inner wall and the outer wall of the apparatus is filled with an adsorbent capable of adsorbing a large amount of MA or PD at a low pressure. Even if MA or PD leaks from the device due to some kind of stimulation / impact, the above adsorbent adsorbs MA or PD, so that leakage prevention and leakage rate relaxation can be achieved.

As an appropriate introduction target of the above-described apparatus for preventing leakage, for example, an MA or PD gas storage apparatus can be cited. This brings about effects such as improving the safety during storage and eliminating the need for cooling during storage.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

[Example 1] (Measurement of MA storage capacity of zeolite 4A)
Zeolite 4A (product code number: 267-00595) purchased from Wako Pure Chemical Industries, Ltd. was used. After the zeolite 4A was heated and vacuumed at 350 ° C. for 15 hours, MA adsorption measurement was carried out using an automatic gas adsorption measurement device (manufactured by Quantachrome, trade name: AUTOSORB-1).
Experimental conditions are
Gas used: Methylacetylene (Aldrich, product number: 295493)
Measurement temperature: 25 ° C
Equilibrium parameter: Tolerance = 0
Equilibration Time = 3 minutes. The results are shown in FIG.
From this result, zeolite 4A was 52 mL / g (9.2 wt%) at 0.01 bar, 60 mL / g (11 wt%) at 0.05 bar, and 77 mL / g (14 wt%) at 0.8 bar. It was shown to adsorb MA. Furthermore, it was shown that 76 mL / g (13 wt%) of MA remained adsorbed at 0.01 bar during the desorption process, which revealed that zeolite 4A has a high MA retention capacity.

[Example 2] (Measurement of PD storage capacity of zeolite 4A)
Zeolite 4A (product code number: 267-00595) purchased from Wako Pure Chemical Industries, Ltd. was used. After the zeolite 4A was preliminarily heated and evacuated at 350 ° C. for 15 hours, PD adsorption measurement was performed using an automatic gas adsorption measurement apparatus (manufactured by Quantachrome, trade name: AUTOSORB-1).
Experimental conditions are
Gas used: propadiene (SYNQUEST, product number: 1300-1-03)
Measurement temperature: 25 ° C
Equilibrium parameter: Tolerance = 0
Equilibration Time = 3 minutes. The results are shown in FIG.
From this result, zeolite 4A was subjected to a PD adsorption process of 84 mL / g (15 wt%) at 0.01 bar, 88 mL / g (16 wt%) at 0.05 bar, and 95 mL / g (17 wt%) at 0.8 bar. Adsorption was shown. Furthermore, it was shown that 92 mL / g (16 wt%) of PD remained adsorbed at 0.01 bar in the desorption process, and it became clear that zeolite 4A has a high PD retention ability.

[Comparative Example 1] (Measurement of MA storage capacity of zeolite 3A)
Zeolite 3A (product code number: 269-00555) purchased from Wako Pure Chemical Industries, Ltd. was used. After the zeolite 3A was preliminarily heated and vacuumed at 350 ° C. for 15 hours, MA adsorption measurement was carried out using an automatic gas adsorption measuring device (manufactured by Quantachrome, trade name: AUTOSORB-1).
Experimental conditions are
Gas used: Methylacetylene (Aldrich, product number: 295493)
Measurement temperature: 25 ° C
Equilibrium parameter: Tolerance = 0
Equilibration Time = 3 minutes. The results are shown in FIG.
From this result, it was shown that zeolite 3A hardly adsorbs MA.

[Comparative Example 2] (Measurement of PD storage capacity of zeolite 3A)
Zeolite 3A (product code number: 269-00555) purchased from Wako Pure Chemical Industries, Ltd. was used. Zeolite 3A was preliminarily heated and evacuated at 350 ° C. for 15 hours, and then PD adsorption measurement was performed using an automatic gas adsorption measurement device (manufactured by Quantachrome, trade name: AUTOSORB-1).
Experimental conditions are
Gas used: propadiene (SYNQUEST, product number: 1300-1-03)
Measurement temperature: 25 ° C
Equilibrium parameter: Tolerance = 0
Equilibration Time = 3 minutes. The results are shown in FIG.
From this result, it was shown that zeolite 3A hardly adsorbs PD.

MA adsorption / desorption isotherm and PD adsorption / desorption isotherm of zeolite 4A. MA adsorption / desorption isotherm and PD adsorption / desorption isotherm of zeolite 3A.

Claims (9)

Adsorption of MA or PD characterized by contacting a gas containing methylacetylene (hereinafter abbreviated as MA) or propadiene (hereinafter abbreviated as PD) with an adsorbent capable of adsorbing 5 wt% or more of MA or PD. Method. The adsorption method according to claim 1, wherein the adsorbent has pores having a pore diameter in the range of 0.35 nm to 1 nm. The adsorption method according to claim 1 or 2, wherein the adsorbent is one of a group consisting of zeolite, silicalite, and activated alumina. The adsorption method according to claim 3, wherein the adsorbent is zeolite. The adsorption method according to claim 4, wherein the zeolite is zeolite A. The adsorption method according to claim 5, wherein the zeolite A is zeolite 4A. After adsorbing 5 wt% or more of MA or PD, when the partial pressure of MA or PD is lowered to 0.01 bar, the adsorbed amount of 5 wt% or more is continuously maintained. The adsorption method according to the above. An apparatus for preventing leakage of MA or PD or reducing the leakage rate, wherein the adsorption method according to claim 1 is used. A gas storage device incorporating the device according to claim 8.

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