MULTILAYER STRUCTURE FOR TRANSPORTING OR STORING HYDROGEN

Abstract

Multilayer structure for transporting hydrogen, including, from the inside, at least one sealing layer and at least one composite reinforcing layer, an innermost composite reinforcing layer being wound around an outermost adjacent sealing layer, the sealing layers of a composition predominantly of at least one semi-crystalline, long-chain polyamide thermoplastic polymer P1i (i=1 to n, n being the number of sealing layers), the Tf of which, as measured according to ISO 11357-3: 2013, is greater than 160° C., with the exception of one polyether block amide (PEBA), up to 50% by weight of impact modifier relative to the total weight of the composition and up to 1.5% by weight of plasticiser relative to the total weight of the composition, the composition being free of nucleating agent, and at least one of the composite reinforcing layers being of a fibrous material.

Claims

1. A multilayer structure intended for transporting, distributing, or storing hydrogen, comprising, from the inside to the outside, at least one sealing layer and at least one composite reinforcement layer, said innermost composite reinforcement layer being would around said outermost adjacent sealing layer, said sealing layers consisting of a composition comprising: more than 50% by weight relative to the total weight of the composition of at least one long-chain polyamide thermoplastic polymer P1i, i=1 to n, n being the number of sealing layers, semi-crystalline including the Tm, as measured according to ISO 11357-3: 2013, is greater than 160° C., in particular greater than 170° C., said long-chain polyamide thermoplastic polymer having an average number of carbon atoms per nitrogen atom greater than 9, excluding a polyether block amide (PEBA), up to 50% by weight of impact modifier, especially up to less than 15% by weight of impact modifier relative to the total weight of the composition, up to 1.5% by weight of plasticizer relative to the total weight of the composition, said composition being devoid of nucleating agent, said at least one predominant polyamide thermoplastic polymer in each sealing layer that may be the same or different, 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 comprising more than 50% by weight, relative to the total weight of the composition, of at least one polymer P2j, j=1 to m, m being the number of reinforcement layers, said structure being devoid of a polyamide polymer layer, said polyamide polymer layer being the outermost and adjacent to the outermost layer of composite reinforcement.

2. The multilayer structure according to claim 1, wherein each sealing layer comprises the same type of polyamide.

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

4. The multilayer structure according to claim 3, wherein each sealing layer comprises the same type of polymer and each reinforcement layer comprises the same type of polymer.

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

6. The multilayer structure according to claim 1, wherein said polymer Phi is a long-chain aliphatic polyamide, or semi-aromatic.

7. The multilayer structure according to claim 1, wherein said polymer P2j is an epoxy resin or epoxy-based resin.

8. Multilayer structure according to claim 6, wherein said multilayer structure consists of a single reinforcement layer and a single sealing layer in which said polymer Phi is a long-chain aliphatic polyamide, or semi-aromatic, the MXDT/10T, the MPMDT/10T and the BACT/10T.

9. 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.

10. 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.

11. 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.

12. The method for producing a multilayer structure as defined in claim 11, wherein it comprises a step of filament winding of the reinforcement layer around the sealing layer.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0202] FIG. 1 shows the Charpy impact notched at −40° C. according to ISO 179-1:2010 of four liners: from left to right PA11, PA12, PA6 and PA66.

[0203] FIG. 2 shows the hydrogen permeability at 23° C. of liners PA12 and HDPE.

[0204] It is expressed in cc.Math.mm/m.sup.2.Math.24 h.Math.atm. It can be expressed in cc.Math.25 μ/m.sup.2.Math.24 h.Math.Pa.

[0205] The permeability must then be multiplied by 101325.

[0206] FIG. 3 shows the Charpy impact notched at −40° C. according to ISO 179-1:2010 of liners PA11 and PA12: for each group of histograms, PA11 is on the left and PA12 is on the right. The first group corresponds to 0% plasticizer, the second group to 7% plasticizer and the last group to 12% plasticizer.

EXAMPLES

[0207] In all the examples, the tanks are obtained by rotational molding of the sealing layer (liner) at a temperature adapted to the nature of the thermoplastic resin used.

[0208] In the event that a composite reinforcement made of epoxy resin or epoxy-based resin, 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.

[0209] In all other cases, a fibrous material previously impregnated with the thermoplastic resin (tape) is used. This tape is deposited by filament winding using a robot with a 1500 W laser heater at a speed of 12 m/min and there is no polymerization step.

Example 1: Charpy Impact Notched at −40° C. According to ISO 179-1:2010

[0210] Two long-chain liners in PA11 and PA12 and two short-chain liners were prepared by rotational molding as above.

[0211] These four liners were Charpy impact tested notched at −40° C. and the results are shown in FIG. 1.

[0212] The cold resistance of long-chain liners is very clearly superior to that of short-chain PA6 and PA66 liners.

Example 2

Permeability of PA 11 and PA12 (Arkema) and HDPE (Marlex® HMN TR-942 (Chevron Phillips)) Liners

[0213] Two long-chain liners: one in PA11 (Arkema) and the second in PA12 (Arkema) and an HDPE liner were prepared by rotational molding and the hydrogen permeability at 23° C. was tested.

[0214] This consists of sweeping the upper face of the film with the test gas (Hydrogen) and measuring the flow that diffuses through the film in the lower part by gas phase chromatography, swept by the carrier gas: Nitrogen

[0215] 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

[0216] The results are presented in FIG. 2 and show that the PA11 liner and the PA12 liner both have a much lower permeability than a HDPE liner.

Example 3: Influence of the Proportion of Plasticizer (N-Butyl Benzene Sulfonamide: BBSA) on the Charpy Impact Notched at −40° C. According to ISO 179-1:2010

[0217] Two liners PA11 and PA12 without plasticizer or comprising 7 or 12% plasticizer (BBSA) relative to the total weight of the composition were prepared by rotational molding.

[0218] These liners were Charpy impact tested notched at −40° C. according to ISO 179-1:2010 and the results are shown in FIG. 3.

[0219] The plasticizer has a detrimental effect when cold, it weakens the structure and increases the permeability, in particular by 50% with 7% of BBSA.

Example 4

[0220] Influence of the proportion of impact modifier (“LT cocktail” having the following composition: Iotader® 4700 (50%)+Iotader® AX8900 (25%)+Lucalene® 3110 (25%)) on the hydrogen permeability of the liner PA12.

[0221] The hydrogen permeability of the PA12 liner, without plasticizer and with or without impact modifier, was tested and is reported in Table 2.

TABLE-US-00002 TABLE 2 Permeability Liner (cc.25 μ/m.sup.2.24 h.atm) PA12 alone  7,300 PA12 + 18% impact modifier 15,000 PA12 + 30% impact modifier 22,000

[0222] The permeability can also be expressed in (cc.Math.25 μ/m.sup.2.Math.24 h.Math.Pa).

[0223] The permeability must then be multiplied by 101325.

[0224] The results show that the proportion of impact modifier influences the hydrogen permeability.

[0225] The greater the proportion of impact modifier, the greater the permeability.

Example 5

[0226] Type IV hydrogen storage tank, composed of a T700SC31E (produced by Toray) carbon fiber epoxy composite reinforcement (Tg 120° C.) and a PA11 sealing layer.

[0227] The operating temperature is sufficient for a rapid filling of the tank, in particular in 3 to 5 minutes.

Example 6 (Counterexample)

[0228] Type IV hydrogen storage tank, composed of a T700SC31E (produced by Toray) carbon fiber epoxy composite reinforcement (Tg 120° C.) and an HDPE sealing layer.

[0229] The operating temperature is too low for a rapid filling of the tank, in particular in 3 to 5 minutes.

Example 7: Type IV Hydrogen Storage Tank, Composed of a T700SC31E (Produced by Toray) Carbon Fiber Epoxy Composite Reinforcement BACT/10T and a PA12 Sealing Layer

[0230] The selected BACT/10T composition has a melting temperature, Tm, of 283° C., a crystallization temperature, Tc, of 250° C. and a glass transition temperature of 164° C.

[0231] The Tg, the Tc and the Tm are determined by differential scanning calorimetry (DSC) according to standards 11357-2:2013 and 11357-3:2013, respectively.

[0232] A BACT/10T PA-based composite has a high Tg matrix, but without having long crosslinking, of the 8 h type at 140° C.

[0233] Therefore, after fiber removal, the tank is finished, which saves 8 hours of process time.