Unloading station for a means of transport
The vaporization of residual CO2 in transport vessels using a heat exchanger addresses the inefficiencies of traditional methods, ensuring complete CO2 recovery and efficient energy use.
Patent Information
- Application Number
- FR2024005877
- Authority / Receiving Office
- FR · FR
- Patent Type
- Utility models
- Current Assignee / Owner
- Filing Date
- 2024-06-05
- Publication Date
- 2025-10-24
- Estimated Expiration
- 2034-06-05
AI Technical Summary
Existing methods for unloading and cleaning cryogenic liquid CO2 from transport vessels risk losing the CO2 molecules and require complex pumping systems, which can damage equipment and are inefficient in energy use.
A system utilizing a vaporizer connected to the transport vessel to vaporize the remaining liquid CO2 using a heat exchanger, allowing recovery of all CO2 without pressure elevation and utilizing existing gas lines for evacuation, combined with pressurization and depressurization cycles to achieve purity.
Enables complete CO2 recovery without losing molecules, reduces equipment damage risk, and optimizes energy use by leveraging existing infrastructure.
Smart Images
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Abstract
Description
Title of the invention: Unloading station for a means of transport
[0001] The present invention relates to an unloading station for a means of transport. The present invention makes it possible to clean a wagon or truck of liquid CO2 without losing the CO2. It also makes it possible to combine the loading and unloading functions for the same bay.
[0002] The invention consists of a loading station (or bay) which can also be used as an unloading and cleaning station (or bay) for a means of transport, for example a wagon, a truck or a boat.
[0003] In all cases, the means of transport is connected to the bay by two connections: a connection at the bottom of the means of transport for the liquid and a connection for the gas in the gas phase of the means of transport.
[0004] According to an object of the invention, there is provided a station for unloading and cleaning a means of transport comprising a means of transport comprising a tank, a pipe for introducing liquid into the means of transport connected to a lower part of the tank and a pipe for allowing the evacuation of gas from the means of transport connected to an upper part of the tank, a vaporizer connected to the lower part of the tank to remove liquid contained in the tank and a pipe connected to the vaporizer and to the upper part of the tank to return vaporized liquid to the vaporizer.
[0005] [Fig. 1] illustrates a loading station according to the invention for loading the tank W of a means of transport, here a wagon, with liquid CO2.
[0006] In the case of using the bay for loading liquid CO2, valves V2 and V4 are closed. Valves V3 and VI are open. Liquid CO2 5 arrives through valve V3 while the gaseous phase 2 from the upper part of tank W above the liquid level, pushed by the liquid, leaves the wagon through valve VL. Liquid 5 arrives from an intermediate CO2 storage either by gravity or pumped by a transfer pump. The gas which escapes from the top of tank W through VI is returned to the CO2 capture unit as flow 3, to an intermediate CO2 storage or is sent to the atmosphere. An analyzer makes it possible to verify that the gaseous CO2 is sufficiently pure to be able to be sent to the storage or to the CO2 liquefier (without going through a purification phase).The analyzer is either fast (directly connected to the wagon, on the gas phase or on the liquid phase, before the VI valve is opened) or with a slower response time.
[0007] In the following cases, the tank W must be unloaded: a. overfilling the tank b. mechanical problem with the tank requiring it to be emptied for repair c. polluted tank
[0008] The objective is to empty the tank but without releasing the contents of the tank into the atmosphere. Liquid CO2 cannot therefore simply be emptied by gravity onto the ground (which would form dry ice). In this case, care must be taken not to lower the pressure in the tank too much (typically keeping it above 7 barg) otherwise there is a risk of freezing the CO2 inside the tank.
[0009] When it is necessary to completely empty the cryogenic liquid from the tank without losing the molecules, there are two possible options: a. drain pump P (but it is then not possible to completely empty the wagon without risking damaging the pump; in fact, the last % of liquid cannot be drawn off without risking also sucking in gas). The advantage of this option is that it allows the cryogenic liquid 7, drawn from the tank via the open valve V4, to be sent to storage or to the capture unit or to the liquefaction unit. It therefore makes it possible to take advantage of the frigories of the cryogenic liquid. The last % of liquid must either be emptied by gravity (losing the molecules) or vaporized using the method described below. It could also vaporize these last % of liquid (typically 5%) by injecting hot gas into the tank but this presents problems. b. vaporization in a heat exchanger V, by opening the valves V4, V5, the vaporized gas 7A being returned to the upper part of the tank W above the liquid level via the open valve VI and the line used with injection of gas 1 under pressure through the open valve V1 to push the liquid into the tank W. This solution, which is that of the invention, has the advantage of allowing the recovery of all the CO2 without introducing elevation constraints. It also allows the recovery of the CO2 under pressure but the frigories are lost.
[0010] More specifically, the cryogenic liquid can be vaporized in a heat exchanger V using either electricity (electric resistance heating a hot water bath), or directly water, or any other heat transfer fluid. If one wishes to take maximum advantage of the frigories of this cryogenic liquid, it is possible to vaporize it in a heat exchanger (typically a brazed plate and fin heat exchanger or a shell and tube heat exchanger) allowing the condensing of gaseous CO2.
[0011] Depending on the degree of cleanliness of the vaporized CO2, it is then possible to choose where the gas is returned to the process. This solution also has the advantage of limiting the impact on the interconnecting pipes between the different zones: unlike the solution with the pump, it is not necessary to return the liquid in a dedicated line but it is possible to use the existing gas line (necessary for filling the tank to evacuate the gas produced by liquid piston effect). The pure CO2 line under pressure is in any case necessary to purify the tank W (using the heat exchanger V to vaporize liquid coming from storage would have been possible but is not optimal in terms of energy).
[0012] The heat exchanger V for vaporizing the cryogenic liquid can also be used to maintain the pressure in the intermediate storage of liquid CO2.
[0013] Once the cryogenic liquid has been purged, it becomes possible to finish purifying the tank W by using pure gaseous CO2 1 under pressure sent via the open valve V2 to carry out pressurization and depressurization cycles and a sweep to achieve the required purity in the tank W.
[0014] Once tank W has been repaired and made pure, it becomes possible to load it using valves VI and V3.
Claims
Claims
1. An unloading station for a means of transport comprising a means of transport comprising a tank (W), a pipe for introducing liquid (5) into the means of transport connected to a lower part of the tank and a pipe for allowing the evacuation of gas (3) from the means of transport connected to an upper part of the tank, a vaporizer (V) connected to the lower part of the tank for discharging liquid contained in the tank and a pipe connected to the vaporizer and to the upper part of the tank for returning vaporized liquid (7A) to the vaporizer.