HUT74552A - Method for delivering and storing of acetylene - Google Patents

Abstract

In a process for transporting and storing acetylene dissolved in a solvent, the solution of acetylene in the solvent is separated by a cover from the gas phase above it. The cover consists of a specific lighter liquid or a film that may be gas permeable or perforated. With the method, a higher storage temperature is possible. On porous packing can be omitted.

Description

The present invention relates to a method for transporting and storing acetylene in a container wherein the acetylene is in the form of a solution in a solvent. The invention further relates to a container in which the acetylene is in solution with a solvent.

At ambient temperature, acetylene is usually transported and stored in steel bottles. To prevent spontaneous decomposition of acetylene, steel bottles are completely filled with a porous mass, such as silica or pumice, containing a solvent for uptake of acetylene. Various other methods, such as those described in U.S. Pat. No. 2,925,385, whereby the porous mass could be omitted when the solvent was -76 ° C, have generally become known in the past to increase storage efficiency. on, kept at a low temperature. In this case, the acetylene partial pressure above the solution in the gas space is very low and accordingly the tendency for acetylene to decompose is low.

The disadvantage of prior art processes is that, without exception, very low storage temperatures are required for acetylene; accordingly, for long-term storage, high cooling performance should be used to maintain low temperatures. At higher temperatures there is a risk that the decomposition reaction in the gaseous phase will spread to the given acetylene.

It is an object of the present invention to provide a process and apparatus for transporting and storing acetylene, which allows a higher storage temperature than before and can thus save cooling power.

82787-5767 SR-Sch

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SUMMARY OF THE INVENTION An object of the present invention is to provide a method for transporting and storing acetylene in a container in which the acetylene is in solution with a solvent, wherein the solution is separated at least substantially by covering the gas phase above.

Surprisingly, when the acetylene solution in the solvent is separated from the gas phase consisting of acetylene and solvent vapor over the solution, the acetylene in the containers becomes stored and transported under safety-critical conditions at higher temperatures than would be expected in the prior art.

The invention will now be described in more detail with reference to the accompanying drawings. The attached drawings show

Fig. 1 is a cross-sectional view of a container over an acetylene solvent mixture with a topsheet consisting of an extremely light liquid; the

Figure 2 is a cross-sectional view of the inside of the container with a film for covering the liquid phase of the acetylene solvent mixture; the

Figure 3 is a detail of the film; the

Fig. 4 is the fixing of the foil on the container wall.

Figure 1 shows a schematic diagram of a container 1 for a mixture of acetylene solvent 2 covered by a particularly light liquid 3.

Fig. 2 is a cross-sectional view of a container containing 2 acetylene solvent mixtures. A foil 4 is fastened to the wall of the container with a fastening device 5.

Figure 3 is an enlarged view of the portion of Figure 2 marked Y. Herein, the foils 4 are presented in the form of a three-layer foil. The distance between two films is maintained by the spacers 6 at a maximum possible value.

Fig. 4 shows a detail marked with Z by means of the fastening device 5 by which the foil 4 is fastened to the wall of the container. The foil 4 is clamped between two flanges 7 which are held together by screws 8.

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In accordance with the present invention, as illustrated in Figure 1, the acetylene solvent mixture is overshadowed by a liquid which has a specific gravity lower than the acetylene solvent mixture. In the case of decomposition of acetylene, for example, depending on the presence of a source of ignition, the reaction absorbs and distributes evenly the enthalpy responsible for the further evaporation of acetylene from solution and the further decomposition of acetylene in the liquid phase. This prevents further decomposition of acetylene in solution and enthalpy-dependent transition of acetylene to the gas phase. Suitable coating fluids include, in particular, liquids which are substantially impermeable to acetylene, such as lower alkanes such as isopentane, n-hexane and n-heptane, and mixtures thereof. Other compounds, such as high boiling point olefins, which meet the density requirements for the acetylene solvent mixture and the inertness requirements for the solvent and acetylene, are obviously useful. In this embodiment of the invention, acetylene may be removed from the acetylene solvent phase by increasing pressure and / or temperature. At this point, the released acetylene is bubbled through the ultra-light liquid layer and can be withdrawn. In a further embodiment of the process according to the invention a gas permeable or acetylene permeable film 4 is used which floats on the surface of the acetylene solution. The film is captured in the fastener 5 of Figure 2, which connects it seamlessly to the container wall. Furthermore, the film 4 is not stretched, but preferably has a larger surface area than the horizontal cross-sectional area of the container so that it always contacts the surface of the acetylene solvent mixture. When the filling height of the container 1 drops slightly due to the removal of acetylene, the film 4 adapts to it. For example, any plastic that is chemically resistant to the acetylene solvent mixture is used as a film material. In addition, microperforated or porous plastic films can be used to cover the liquid phase. The film used in the present invention has thermal insulation • · · * ««

Also, coating it with a metallic reflective coating for its purpose results in the desired result. Finally, the acetylene permeable film can be formed in such a way that it completely surrounds the volume of the solvent and acetylene liquid. It is possible to fill such a volume by means of a filler pipe connection which is connected to the foil. As shown in Figure 3, the invention is not limited to the use of a film. Multiple layers can be stitched together and arranged in parallel. In a preferred embodiment, three films are used. It is possible to fasten the foils by means of the fastening device 5 according to Fig. 4, in which the foils are held between two flanges 7 which are held together by screws 8. Floating lumps can also be applied to the liquid surface, which behave similarly as insulators. Finally, it is understood that multiple films and layers may be applied one above the other in pieces. In the case of coating with permeable materials such as films, the removal of acetylene from the gas space can be accomplished in a conventional manner. For example, in the case of coating with a material substantially impermeable to acetylene, the acetylene solvent mixture may be removed directly and separated for use in a separator. DMF (dimethylformamide) is preferably used as the solvent, but other solvents such as acetone or solvent mixtures commonly used to transport acetylene may be used.

The process of the present invention now makes it possible to store and transport acetylene at higher temperatures than in the prior art. Especially for longer storage times, this can reduce cooling performance and the associated cost.

Claims (14)

A process for transporting and storing acetylene in a container (1) wherein the acetylene is in solution with a solvent, characterized in that the solution is separated from the gas phase above by covering at least a large part thereof. Process according to claim 1, characterized in that the separation is carried out with a liquid having a specific gravity less than the specific gravity of the solution. 3. The process of claim 2, wherein the liquid comprises at least one of the isopentane, n-hexane and n-heptane moieties. A process according to claim 1, characterized in that the separation is carried out with a gas permeable film. The process according to claim 4, characterized in that the separation is carried out with a microperforated film. Process according to claim 4 or 5, characterized in that the separation is carried out with a reflective film coated with a metal. 7. A process according to any one of claims 1 to 3, characterized in that the separation is carried out with a film which completely surrounds the solution. 8. A process according to any one of claims 1 to 3, characterized in that at least two films are used for the separation. 9. A container for transporting and storing acetylene, wherein the acetylene is in solution with a solvent, wherein a separating means is provided in the container (1) to cover at least a large portion of the surface of the solution. • · · · «· ···· 10. A container according to claim 9, wherein the separating means is a substantially sealed liquid having a specific gravity less than the specific gravity of the solution. Container according to claim 9, characterized in that a foil is arranged in the container as a separating device. Container according to claim 11, characterized in that the film is gas permeable. Container according to claim 11 or 12, characterized in that the film is formed as a metal-coated reflecting film. 14. A 11-13. A container according to any one of the preceding claims, characterized in that the film surrounds the whole solution.