DE1542442A1 - Method and device for supplying and / or removing gas hydrates from a container - Google Patents

Description

DR.B.T.PKOHMAKTN. τ «.» * ο »22 Οβ Bl PATENT LAWYERS MiaeilKlWBlHMi

description

to the patent application

SHELL INTERNATIONAL RESEARCH MAATSOHAPPIJ N.V.,

Hague, Netherlands

concerning

Method and device for supplying and / or removing grass hydrates from a container.

The invention relates to methods and devices which make it possible to supply gas hydrates to a container and / or refer to.

It is known that many gases and volatile liquids, together with water, form solid crystallized products which belong to the group of clathrates or lattice compounds and are also referred to as gas hydrates. Such Hydrates consist of crystal lattices of special ice shapes, in which atoms and / or molecules of the substances forming the hydrate are enclosed in cavities that pass through Water molecules are delimited. You can generate gas hydrates by using a gas under suitable pressure and temperature conditions brings into contact with water or a heterogeneous system consisting of a water-containing liquid phase and -Ice is made. Such Gaehydrates are under suitable temperature and printing conditions stable. All examples of forming hydrates ·;

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Gases and liquids are inert gases, also methane, ethane, propane, various butanes, Athens, prophets, acetylene, Chlorine, hydrogen sulfide, sulfur dioxide, carbon dioxide, bromine, carbon tetrachloride, chloroform and ethyl chloride. On off Gas hydrate produced by natural gas can contain 10 percent by weight of natural gas at 0 ° C and a pressure of 25 atü

A decomposition of gas hydrates can be brought about by reducing the pressure and / or adding heat. This decomposition can take place in such a way that the heat, which is required for drainage, is transferred to the system is withdrawn by the transformation of water into ice, so that the ice is regenerated.

There are already processes for the creation and decomposition of Known gas hydrates

To enable the transport of gases, it has been proposed to transform the gases in hydrates, which hydrates! to be introduced into a container, to transport the filled container to the respiration site, to remove the gas hydrates from the container and to release the gas again. Compared to other known methods for the transport of natural gas or methane, for example for the transport of compressed gas or for the transport of condensed or liquefied gas, the transport of gases in the form of hydrates offers the advantage that it is not very high Pressures and very low temperatures are needed to reduce capital and operating costs.

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When transporting gases in the form of gas hydrates in a container, when filling and / or emptying the container special measures are taken

It is a primary object of the invention to provide methods and devices that facilitate the introduction of gas hydrates into a container and / or facilitate the removal of the gas hydrates from a container

The inventive method is that the gas hydrates before filling or emptying the container in a with With the help of pumps, the suspension can be converted into a pumpable suspension, namely by adding a liquid to its temperature is at most about 0 ° C, after which the suspension is introduced into the container or removed from the container

Filling or withdrawing gas hydrates in the form of a Floating offers compared to handling dry Gas hydrates have considerable advantages, because you can use some mechanical conveying means, e.g. conveyor belts or Avoid buckets, and the suspension can easily be pumped into or pumped out of the container.

In an expedient embodiment of the invention, the liquid is separated from the gas hydrates again after the suspension has been introduced into the container · This separation of the liquid from the gas hydrates can be advantageous take place in the container.

An advantage of separating the liquid after the suspension has been introduced into the container is that the Space available in the container only for storage and / or transport

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porting of practically dry gas hydrates can serve. With in other words, the space available in the container is used in the most economical way.

A device for performing the method according to the invention comprises at least one filter element which is in the with the container to be filled with the gas hydrates is arranged, at least one device for dispensing and / or supplying a liquid, which is in communication with the filter element, as well as a device for supplying said suspension to the Container or for discharging the suspension.

The invention is illustrated more schematically in the following Drawings on several exemplary embodiments explained in more detail

Fig. 1 shows schematically an embodiment of a device for performing the method according to the invention.

Fig. 2 shows schematically a modified embodiment of a device for performing the method according to Invention.

In Fig. 1, a container for storing gas hydrates is inagesamt denoted by 1. The container 1 is equipped with a vertically arranged tubular filter element 4, which extends over the entire height of the container. The walls 6 of the Filter elements 4 consist of a suitable filter material, e.g. a metal wire mesh, which allows liquid to pass through, Retains gas hydrates, however. The lower end of the filter element 4 is connected to a device 5 for drawing off and / or supplying a liquid. When setting up 5

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it is usually a pipe in which a suitable valve 7 is switched on · devices 2 and 3 for Inlet and outlet of the suspension are on the upper end of the Container 1 arrangedf here it is about pipe socket, each equipped with a valve 8 or 3 *

Fig. 2 shows a generally designated 10 container for storing U-ashydrates. The container 10 is equipped with two vertically arranged tubular filter elements 11 and 12. The walls 13 and 14 of these filter elements consist of a suitable filter material, for example a metal wire mesh, which allows liquids to pass through but retains gas hydrates. The lower end of the filter element 11 is connected to a device for discharging and / or supplying a liquid, while the lower end of the filter element 12 is connected to a device 16 which is also used for discharging and / or supplying a liquid. The devices 15 and 16 are normally pipelines into which suitable valves 17 and 18 are switched. A device 19 for feeding and discharging a suspension in the form of a pipe with a (valve 20 is disposed on the upper end of the container 10th An additional means 22 for supplying a liquid is installed in the lower! Part of the side wall of the container 10th The device 22 is normally designed as a pipe with a suitable valve 21.

The supply of water hydrates from the container is as follows described

The ö-aehydrate be Beifüge "a liquid into a means of pumps fördtrbart Ant" chwemmung verwandelet J 5a #

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Quantity ratio between the liquid to be added and the dry gas hydrate can be, for example, 1: 1. Water can be used as the liquid, both fresh and water Sea water · Instead of this, one can use water to which an agent for lowering the freezing point has been added, e.g. methanol or glycol. The temperature of the liquid to be added should not exceed about 0 ° C. In most cases, the The temperature of the liquid to be added is selected so that it is approximately equal to the weight temperature of the gas hydrates.

Then the gas hydrates in the manner described in a have been converted by pumps conveyable suspension, they are via the charging devices 2 and / or 3 in the container 1 of FIG. 1 is pumped. The suspension immediately sinks to the deepest part of the container 1, and the liquid flows through the wall 6 of the tubular filter element 4 and within the filter elements eu of the liquid discharge line 5. Thus, practically dry gas hydrates, which are very stable, remain in the container 1) they collect from the bottom of the container 1 from in the upward direction. In this way, a high packing density of the gas hydrates in the container 1 is achieved. After the container 1 has been filled with the gas hydrates, the valves 7, 8 and 9 are closed. The gas hydrates can then be used Storage remain in the container 1, and during this time the container can be transported to the destination where the container can be emptied. The emptying of the container is described in more detail below.

In the embodiment according to FIG. 2, the container 10 daduroh filled, that the pumps can be conveyed

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Flooding is fed to the container via the filling device 19 will. In this case, the suspension immediately sinks to the lowest part of the container 10, while the liquid passes through the walls 13 and 14 of the tubular filter elements 11 and 12 penetrates to to be discharged via the interior of the filter elements and the discharge lines 15 and 16. Thus remain in the container 10 practically dry gas hydrates that are very stable and collect upwards from the bottom of the container. In this way a high packing density of the ashydrates in the container 10 is achieved. After the container 10 has been filled with the gas hydrates, the valves 17, 18 and 20 are closed. It should be noted that the valve 21 of the additional liquid supply device 22 remains closed during the entire filling process, The üasnydrate can then in the container 10 during the desired Period of time are stored during which the container may be transported to another location where to empty the container.

To the gas hydrates from the container of the invention To remove the device, follow the procedure described below Way before. .

The gas hydrates present in the container 1 are converted into a pumpable suspension by a liquid that has the same properties as the liquid described above, This liquid is about the Feed device 5, the tubular filter element 4 and through the wall 6 of the filter element into the container 1 initiated. This creates a suspension in the container, which is discharged via the extraction devices 2 and / or 3

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using suitable pumping equipment to prevent some of the gas hydrates from remaining in the container 1, especially those present in the lowest part of the container Gas hydrates, it is possible to place the container 1 optionally on its bottom or on the side walls near the bottom with one or more additional liquid supply devices to provide. The supplied liquid can then with the aid of one or more of these additional supply devices and if necessary also distributed over the filter element 4 will.

The emptying of the container 10 of the embodiment according to Fig. 2 is described below.

In order to convert the gas hydrates in the container 10 into a pumpable suspension, a liquid is fed in which has the same properties as the liquid described above. This liquid is introduced into the container 10 via the feed devices 15 and / or 16, the tubular filter elements 11 and / or 12 and through their walls 13 and 14, respectively. This creates a suspension in the container, which is removed via the extraction device 19 using a suitable pump device. In order to prevent some of the gas hydrates from remaining in the container, especially in the lowest part of the container, it is possible, if necessary, to provide one or more additional liquid supply devices in the base or in the side walls near the base of the container InfeedB means built into the side wall of the container 10 near the container bottom is at 22 in FIG

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indicated. In this Ji'all, the liquid can pass through an or several such additional liquid supply devices and optionally also via the filter elements 11 and / or be distributed.

During the storage of the gas hydrates in container 1 or It is desirable to keep the gas hydrates dry or essentially dry. For this purpose, it can be ensured that the liquid released during storage, ζ.Β * melt water, over the filter element 4 »11 or 12 and in the ground or the walls of the container 1 or 10 provided openings is discharged. This increases the stability of the gas hydrates, and conglomeration is counteracted.

After the gas hydrates have been discharged in the form of a suspension the liquid is separated from the gas hydrates, and then steps are taken to remove the gas from the gas hydrates to release. The release of the gas from the gas hydrates can be effected in such a way that the greater part of the ice is recovered. This Sis can then be used again when generating be used by gas hydrates. Here, the greater part of the ice goes through a cycle, so that the production of the required ice cheaper. To transport this ice back to the place where the container was again filled with gas hydrates is to be filled, the ice can also be reinserted into a container in the form of a suspension » which is then transported to the destination. Bort then serves this ice cream for renewed replacement of (Jaefaydratun®

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The liquid that the ü-ashydrates after removal The suspension that has been separated from the container can be used again to convert further gas hydrates into a suspension to transform

Furthermore, the liquid, which is deposited from the (iashydrates was used again after the suspension was introduced into the container, in order to be used in a continuous Process more gas hydrates into a suspension transform so that these gas hydrates can be introduced into a container in the form of a suspension

The method according to the invention is suitable for storing natural gas or methane in the form of gas hydrates in one Container or to be used in the transport of natural gas or methane in ü'orm of gas hydrates in a container. The transport can be carried out in such a way that the container is placed in or on a suitable transport device, e.g. ι ship, arranges

Claims

009816/1407

Claims (1)

PATENT CLAIMS 1.Method of supplying the hydrate to a container and / or to be found, characterized in that the gas hydrates, before they are fed into or removed from a container, are thereby converted into a pumpable suspension that a liquid is added to them whose ' Temperature is at most 0 ° C, and that the -aufschwemmung thus generated is fed or removed from the container. 2. The method according to claim 1, characterized in that that * the .liquid after the introduction of the suspension is separated again from the gas hydrates in the container. 3. The method according to claim 2, characterized in that the conversion of the gas hydrates into a pumpable suspension with the help of a continuously running t the process is effected, the separated liquid being added immediately to further gas hydrates to be supplied to a container in order to convert the gas hydrates into one to transform pumpable suspension 4. The method according to claim 2 or 3 »characterized in that the separation of the liquid from the Gas hydrates is effected within the container. 5. The method according to claim 1 to 4, characterized in that the conversion of the gas hydrates into one 0 0 9 8 1 6 / U 0 7 -12 - 1A-31 007 pumpable suspension is effected before removal from the container in the container in which the gas hydrates are located. 6 · The method according to claim 1 to 5, characterized in that the liquid after the removal of the The suspension is separated from the gas hydrates again from the container will. 7. Method according to Claims 1 to 6, characterized in that the is located at a specific location After filling, the container is transported to another destination, where the container is emptied. 8. The method according to claim 7, characterized in that the container on a transport device is arranged or forms part of the transport device. y. Method according to claim 8, characterized in that the container is arranged on a ship or forms part of a ship. 10. The method according to claim 6 to 9, characterized in that the gas after emptying the container is released from the gas hydrates, and that in the container remaining ice is transported back to the location where the container was filled, with this ice at the said Site is used to generate new Gaehydrate. 11 · Method according to claims 1 to 10, because g e k e η η draws, that the gas is natural gas or methane acts. 0098 16/1407 15Λ2Α42 -J3-1Α-31 007 12. Device for performing the method according to claim 1 to 11, characterized by at least a .filter element (4, 11, 12), which is in the container (1, 10) is arranged to be filled with the gas hydrates, at least one opening into the filter element device (5, 13, 16) for removing and / or supplying liquid as well as a Device (2, 3 »19) to supply or remove a suspension from the container · 13 · Device according to claim 12, characterized in that I indicates that at least one filter element is present, that the filter element is tubular and is arranged upright in the container, and that the filter element is approximately over the entire height of the container 14. Device according to claim 12 or 13, characterized in that additional devices (22) are fed into the bottom and / or the side wall of the container Sound liquid are built in " ( 15 · transport device, marked by a device according to Anepruoh 12 to 14 · 16. Ship, characterized by a device naoh claim 12 to 14 · 00 98 16 / Blank page