MULTILAYER STRUCTURE FOR TRANSPORTING OR STORING HYDROGEN

Abstract

A multilayer structure for transporting, distributing and storing hydrogen including, from the inside to the outside, a sealing layer and at least one composite reinforcement layer, the sealing layer including from the inside to the outside: a layer of a composition including: a short-chain polyamide thermoplastic polymer, more than 15% and up to 50% by weight of impact modifier, or including: a semi-crystalline long-chain polyamide thermoplastic polymer, up to 50% by weight of impact modifier, up to 3% by weight of plasticizer; a hydrogen barrier layer; a layer of a composition including: a short-chain polyamide thermoplastic polymer, more than 15% and up to 50% by weight of impact modifier, or including: a semi-crystalline long-chain polyamide thermoplastic polymer, up to 50% by weight of impact modifier, up to 3% of weight of plasticizer, the innermost composite reinforcement layer being wound around the sealing layer.

Claims

1. A multilayer structure intended for transporting, distributing and storing hydrogen, comprising, from the inside to the outside, a sealing layer (1) and at least one composite reinforcement layer (2), said sealing layer comprising, from the inside to the outside: a layer (a) consisting of a composition predominantly comprising: a short-chain aliphatic polyamide thermoplastic polymer, the Tm of which, as measured according to ISO 11357-3: 2013, is greater than 160° C., more than 15% and up to 50% of impact modifier, or predominantly comprising: a long-chain semi-crystalline aliphatic polyamide thermoplastic polymer, the Tm of which, as measured according to ISO 11357-3: 2013, is greater than 160° C., up to 50% by weight of impact modifier, relative to the total weight of the composition, up to 3% by weight of plasticizer relative to the total weight of the composition; optionally a layer of binder; a hydrogen barrier layer; optionally a layer of binder; a layer (b) consisting of a composition predominantly comprising: a short-chain aliphatic polyamide thermoplastic polymer, the Tm of which, as measured according to ISO 11357-3: 2013, is greater than 160° C., more than 15% and up to 50% of impact modifier, or predominantly comprising: a long-chain semi-crystalline aliphatic polyamide thermoplastic polymer, the Tm of which, as measured according to ISO 11357-3: 2013, is greater than 160° C., up to 50% by weight of impact modifier relative to the total weight of the composition, up to 3% by weight of plasticizer relative to the total weight of the composition, said innermost composite reinforcement layer (2) being wound around said sealing layer (1), and at least one of said composite reinforcement layers consisting of a fibrous material in the form of continuous fibers, which is impregnated with a composition predominantly comprising at least one polymer P1j, j=1 to m, m being the number of reinforcement layers.

2. The multilayer structure according to claim 1, wherein said layer (a) and said layer (b) comprise the same polyamide.

3. The multilayer structure according to claim 1, wherein said layer (a) and said layer (b) comprise a different polyamide.

4. The multilayer structure according to claim 1, wherein the polyamide of layers (a) and/or (b) is a long-chain aliphatic polyamide.

5. The multilayer structure according to claim 1, wherein the polyamide of layers (a) and/or (b) is a short-chain aliphatic polyamide.

6. The multilayer structure according to claim 1, wherein each reinforcement layer comprises the same type of polymer.

7. The multilayer structure according to claim 1, wherein it has a single reinforcement layer.

8. The multilayer structure according to claim 1, wherein said polymer P1j is PA1010, PA 1012, PA 1212, PA11, PA12.

9. The multilayer structure according to claim 1, wherein said polymer P1j is an epoxy resin or epoxy-based resin.

10. The multilayer structure according to claim 1, wherein said multilayer structure consists of a single reinforcement layer and a sealing layer, in which layers said polyamide of layers (a) and/or (b) is a short-chain aliphatic polyamide, or a long-chain aliphatic polyamide, and said polymer P1j is an epoxy resin or epoxy-based resin.

11. The multilayer structure according to claim 1, wherein said multilayer structure consists of a single reinforcement layer and a sealing layer, in which said polyamide of layers (a) and/or (b) is a short-chain aliphatic polyamide, or a long-chain aliphatic polyamide, and said polymer P1j is a long-chain aliphatic polyamide, or a semi-aromatic polyamide.

12. The multilayer structure according to claim 1, wherein the fibrous material of the composite reinforcement layer is selected from glass fibers, carbon fibers, basalt fibers or basalt-based fibers, or a mixture thereof.

13. The multilayer structure according to claim 1, wherein said structure further comprises at least one outer layer consisting of a fibrous material made of continuous glass fibers, which is impregnated with a transparent amorphous polymer, said layer being the outermost layer of said multilayer structure.

14. A method for producing a multilayer structure as defined in claim 1, wherein it comprises a step of preparing the sealing layer by extrusion blow molding, rotational molding, injection molding and/or extrusion.

15. The method for producing a multilayer structure as defined in claim 14, wherein it comprises a step of filament winding of the reinforcement layer, around the sealing layer and prepared beforehand.

Description

EXAMPLES

[0280] Example 1: Permeability to hydrogen at 23° C. of PAll liners and a liner of the invention was tested.

[0281] A2 mm sealing layer (liner) having five layers according to the invention, constituting a tank of the invention, was obtained by extrusion blow molding at a temperature suited to the nature of the different thermoplastic resins used.

[0282] The liner has the following structure:

[0283] PA11//binder//EVOH//binder//PA11, the layers having the following respective thicknesses: (900 μm//50 μm//100 μm//50 μm//900 μm).

[0284] PA11 is a polyamide 11 having an Mn (number-average molecular weight) of 45,000. The melting point is 190° C.; its enthalpy of fusion is 56 kJ/m.sup.2.

[0285] The binder is a Tieflex S442®sold by Arkema.

[0286] EVOH is an EVOH containing 32% ethylene, of EVAL FP101B type (from Eval)

[0287] In the event that a composite reinforcement made of epoxy resin or epoxy-based resin is wound over the liner, use is then made of a process of wet filament winding, which consists in winding fibers around the liner, which fibers have been previously pre-impregnated in a bath of liquid epoxy or a bath of epoxy-based liquid. The reservoir is then polymerized in an oven for 2 hours.

[0288] The permeability of a liner made of PA11 and a liner of the invention is measured according to a test which consists in flushing the upper face of a film made of PA11 or consisting of the five layers of the invention with the test gas (Hydrogen) and in measuring by gas chromatography the flow which diffuses through the film in the lower part, flushed by the vector gas: Nitrogen.

[0289] The experimental conditions are presented in Table 1:

TABLE-US-00001 TABLE 1 Device LYSSY GPM500/GC coupling Detection Chromatographic (TCD) Column Poraplot Q (L = 27.5 m, Dint = 0.530 mm, Ep.film = 20 μ) Vector gas NITROGEN Diffusing gas HYDROGEN U (H2) Test surface area 50 cm.sup.2 Calibration Absolute by direct injection through a septum Pressure at column head 18 psi Oven temperature Isothermal 30° C. Detector temperature 200° C. detector: TCD [−] Injector temperature Temperature of the lyssy injection loop Temperature/ 23° C./0% RH relative humidity

[0290] The results are presented in Table 2 and show that the liner of the invention has much lower permeability than that of a liner made of PA11.

TABLE-US-00002 TABLE 2 PA11 Liner of liner example 1 (2 mm) (2 mm) Permeability 50 10 (cc.mm/m 2.24 h.atm) measured at 23° C. under 0% relative humidity (RH))

[0291] The permeability can also be expressed in (cc.mm/m.sup.2.24h.Pa).

[0292] The permeability must then be multiplied by 101325.