Use of polymer materials

Abstract

The invention relates to the field of hydrogen energy. It proposes the use of a polymer material obtained by heat radiation treatment of a polytetrafluoroethylene blank, in which the polymer is heat-treated after ion radiation treatment in order to produce products for the generation, transportation, storage, separation and containment of hydrogen. The technical result is that the operational properties of hydrogen industrial plants and the resistance to corrosive environments are improved by using such a polymer material, which reduces the adverse effects of corrosive environments on products for the production, transportation, storage, separation and containment of hydrogen.

Description

Technical Field

[0001] The present invention relates to the field of hydrogen energy, and more specifically to a novel use of polymer materials obtained by the method described in Russian Patent No. 2669841 in products designed for the generation, transportation, storage, separation and containment of hydrogen, which is currently used in the energy, chemical, transportation and other industrial fields. Background Art

[0002] There is a well-known lack of polymeric materials that can reliably generate, transport and contain hydrogen. In the hydrogen and ammonia industries, in the production of liquefied natural gas (LNG) and other industries, there is a lack of polymeric materials that combine the following properties: low hydrogen permeability, the ability to operate over a wide temperature range, tolerance to aggressive environments, low coefficient of friction, high wear resistance, and high physical and mechanical properties (e.g., tensile strength, compressibility, lack of cold flow, etc.), while also having barrier and membrane properties.

[0003] Due to their small size, molecular and atomic hydrogen can easily penetrate the structure of the material, causing degradation. In addition, due to temperature fluctuations and pressure changes, pressurized hydrogen can penetrate the polymer material structure, causing swelling, cracking and reduced physical, mechanical, film and barrier properties. This degradation is particularly evident in high pressure applications, where system depressurization (or rapid temperature changes) causes hydrogen to expand within the free volume and pores of the polymer.

[0004] Therefore, the production, transportation, storage and use of molecular and atomic hydrogen are labor-intensive and cost-challenging.

[0005] The lack of materials that meet all required standards forces device manufacturers to use composite materials, alloys, or various materials in the form of one material coated / layered on another, which significantly increases product costs.

[0006] Disadvantages of all known materials include the inability to simultaneously provide low hydrogen permeability, the ability to operate over a wide temperature range, resistance to aggressive environments, and the ability to withstand the pressure and temperature changes of cycling in a hydrogen environment. Summary of the invention

[0007] The object of the present invention is to provide a new use of polymer materials obtained by the method described in Russian Patent No. 2669841, in particular for the production of products capable of reliably containing, transporting and storing hydrogen.

[0008] The technical achievement of the present invention is to improve the operating properties and resistance to corrosive environments of hydrogen industrial equipment by using a polymer material obtained by the method described in Russian Patent No. 2669841, and the polymer material is superior to other materials in terms of the combination and value of properties that reduce the adverse effects of corrosive environments on products used for the production (accumulation), transportation, storage, separation and containment of hydrogen.

[0009] The technical achievement is achieved by treating a polymer material obtained by treating a polytetrafluoroethylene (PTFE) blank with thermal radiation, wherein the blank is exposed to high-energy ionizing radiation in an oxygen-free environment at a temperature strictly above the melting point of the polymer crystalline phase until the absorbed dose reaches 0.5-500 kGy. During irradiation, the polymer temperature drops by no more than 0.5°C / 10 kGy. After exposure to ionizing radiation, the polymer is thermally treated for use in products designed for the generation, transportation, storage, separation and containment of hydrogen.

[0010] In certain embodiments, the polymer material obtained by the method described in Russian Patent No. 2669841 is used as a sealing, friction, anti-friction or barrier material for pipes, pipeline components, shut-off valves, compressors, gas pumping units, pumps, hydrogen storage tanks, ammonia, liquefied natural gas, membranes, bearing components and other applications.

[0011] The polymer material formed through the combined effects of ionizing radiation, temperature and an oxygen-free environment is still chemically polytetrafluoroethylene, maintaining its inherent chemical and heat resistance while allowing for a gradual structural transition from membrane properties to barrier properties. The material can be used as a stock material for products used for the generation, transportation, storage, separation and containment of hydrogen.

[0012] By changing the structure of PTFE through the method described in Russian Patent No. 2669841, the polymer material obtains barrier and membrane properties, as well as high wear resistance and excellent strength characteristics (such as tensile strength, compressibility, lack of cold flow, etc.), regardless of the type, form or production method of the polymer blank, which is achieved through the combined effects of ionizing radiation, temperature and oxygen-free environment.

[0013] The present invention is carried out using an apparatus whose main components are an electron accelerator and a thermal radiation chamber (TRC). BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention is illustrated by the accompanying drawings, in which:

[0015] Figure 1 The permeability of the polymer material membrane is shown;

[0016] Figure 2 shows a sealed chamber with a separated gas space, external view;

[0017] Figure 3 Shown is a sealed chamber with a separated gas space, interior view. DETAILED DESCRIPTION

[0018] Initially, fluoropolymers, particularly polytetrafluoroethylene (PTFE), are prepared according to conventional techniques for processing fluoropolymer materials. The PTFE stock can be in the form of plates, bushings, rods or various other geometric shapes and components.

[0019] Then, the obtained PTFE blank (hereinafter referred to as "blank") is transferred to the preparation area and placed in a thermal radiation chamber (TRC). In the TRC, oxygen is evacuated to residual pressure, and then the chamber is filled with an inert gas (such as argon, nitrogen, etc.) to overpressure.

[0020] In TRC, the blank is heated at a rate not exceeding 60°C / h to a temperature above the first melting temperature of the crystalline phase (for unsintered PTFE, this temperature is 335°C) but not exceeding 380°C, and then maintained at a constant temperature above the melting temperature of the crystalline phase but not exceeding 380°C.

[0021] The billet is then directed to an irradiation zone, ensuring that the temperature of the fluoropolymer does not drop below its melting temperature.

[0022] In the TRC irradiation zone, the blank is treated with ionizing gamma radiation using an electron accelerator at an irradiation rate of up to 10 kGy / s at a temperature above the melting temperature of the crystalline phase but not exceeding 380° C. Irradiation is performed until an absorbed dose of 0.5-1000 kGy is reached, wherein the temperature drop of the product during processing is from 0.001° C. / 10 kGy to 15° C. / 10 kGy.

[0023] After irradiation, the blanks were subjected to additional heat treatment in a heating / cooling mode, in the temperature range from the onset of crystallization of the processed PTFE to 380°C, to normalize and stabilize the properties.

[0024] The final stage of processing consists in cooling the treated blank to room temperature at a rate not exceeding 60°C / h.

[0025] In addition to the above-mentioned bremsstrahlung radiation, the fluoropolymer blanks may be treated using alpha radiation, gamma radiation, electron radiation, high energy neutrons and protons, radiation from natural sources, and any other type of ionizing radiation.

[0026] Thus, the resulting polymer material blank, which provides significant performance improvements, particularly increased resistance to aggressive hydrogen environments, can be used as:

[0027] - Sealing, friction, anti-friction, and barrier materials for various pipe and pipeline components (corrosion-resistant inserts in pipes, flange joints, pipe and fitting materials, packing glands, windings, etc.);

[0028] - Sealing, friction, anti-friction and barrier materials for stop valves (various gaskets, seals, seats, ball seals, plugs, washers, bushings, glands, etc.);

[0029] - Sealing, friction, anti-friction, barrier materials for compressors, gas pumping units, pumps (sliding plates, piston rings, various bearings and bearing elements, various seals, packing glands, etc.);

[0030] - Sealing, friction, anti-friction, barrier materials for hydrogen, ammonia and LNG storage tanks (cylinders, tubes, industrial storage systems, various seals, inserts, etc.) in the following forms: oriented and non-oriented films, heat shrinkable films, heat expandable sleeves and bushings, heat shrinkable sleeves and bushings, plates, bushings, rods, containers or other items;

[0031] - Materials for various membranes (polymer base materials for proton tracking membranes, polymer base materials for composite proton membranes, polymer base materials for electrolytic membranes, etc.);

[0032] - Sealing, friction, anti-friction, barrier materials for bearing components (rings, separators, etc.).

[0033] Industrial Applicability

[0034] Examples of embodiments of the present invention

[0035] Example 1. Use of the polymer material of the present invention as a sealing, friction, anti-friction and barrier material for various pipes. Products such as corrosion-resistant inserts in pipes, flange joints, materials for pipes and fittings, glands, windings, etc. are manufactured from a blank of the polymer material obtained by the above method, the blank being in the form of a plate, bushing or rod, and then molded. The molding process is carried out to impart a shape memory effect to the material, and is carried out by heat treating the polymer material blank at a temperature of 20° C. to 370° C., so that the contact during use is maximized.

[0036] The introduction of these products will significantly improve the operating properties of pipes and pipeline components due to high resistance to hydrogen permeation and other beneficial properties (such as porosity, wear resistance, etc.).

[0037] Example 2. Use of the polymer material of the present invention as a sealing, friction, anti-friction and barrier material for pipeline stop valves (specifically, various gaskets, seals, seats, ball seals, plugs, washers, bushings, glands, etc.). The products are manufactured from a blank of the polymer material obtained by the method of the present invention, which is in the form of a plate, bushing or rod, and then processed by using lathe or any other suitable machining method. Due to its high resistance to hydrogen permeation and other favorable properties (such as porosity, wear resistance, etc.), the introduction of these products will significantly improve the operating properties of barrier materials.

[0038] Example 3. Use of the polymer material obtained by the method according to the invention as sealing, friction, anti-friction and barrier material for compressors, gas pumping units and pumps (in particular, sliding washers, piston rings, various bearings and bearing assemblies, various seals, packing glands, etc.). The products are manufactured from blanks of the polymer material according to the invention, which are in the form of plates, bushings or rods, and are subsequently processed by using lathe or any other suitable machining method, similar to the initial fluoropolymer. The introduction of these products will significantly improve the operating properties due to the high resistance to hydrogen permeation and other properties (such as porosity, wear resistance, etc.).

[0039] Example 4. Use of the polymeric material according to the invention as sealing, friction, anti-friction and barrier material for storage tanks (cylinders, various storage systems, etc.) for hydrogen, ammonia and liquefied natural gas. Products made of oriented and non-oriented films, heat-shrinkable films, heat-expandable sleeves and bushings, heat-shrinkable sleeves and bushings, plates, bushings, rods, containers or other articles are made from blanks of the polymeric material according to the invention, which are in the form of plates, bushings or rods, and are subsequently processed by using lathes or any other suitable machining methods, similar to the initial PTFE, to obtain the final product (insert). The introduction of these products will significantly improve the operating properties due to the high resistance to hydrogen permeation and other properties (such as porosity, wear resistance, etc.).

[0040] Example 5. Use of the polymer material according to the invention as a polymer base for membranes, in particular for tracking membranes, composite membranes, electrolytic membranes, proton exchange membranes, etc. The membranes are manufactured from a blank of the polymer material obtained by the method according to the invention, in the form of a plate, bushing or rod, by dissolving the blank into a membrane or by any other method of producing a membrane from a bulk material, followed by the generation of pores using known methods. Due to their physicochemical properties (wide operating temperature range, resistance to aggressive environments, lack of cold flow), these membranes have a significantly longer service life.

[0041] Example 6. Use of the polymer material obtained by the process described in the invention as sealing, friction, anti-friction and barrier material for various bearing components (in particular, rings, separators, etc.). Products are manufactured from blanks of the polymer material described in the invention in the form of plates, bushings or rods, which are subsequently machined by using lathe or any other suitable machining method, similar to the original PTFE. The introduction of these products will significantly improve the operating properties due to the high resistance to hydrogen permeation and other properties (such as porosity, wear resistance, etc.).

[0042] To evaluate the hydrogen permeation resistance of the materials of the present invention, 20 micron thick films were produced. The hydrogen permeation test was carried out in a sealed chamber with a separated gas space (Electrochem 25 cm 2 ). The hydrogen flow rate was set at 80 ml / min and the air flow rate was 20 to 100 ml / min. Tests comparing membranes made from Teflon and Nafion 211 materials (Teflon-PTFE trademark; Nafion - PTFE-based perfluorosulfonic acid ion exchange membrane) produced Figure 1 The results shown, in which the permeabilities of polymer material membranes obtained by the process described in the present invention (item PTFE), conventional PTFE and Nafion 211 (material used in hydrogen energy applications) are presented.

[0043] The hydrogen permeability of the membrane made of the polymer material obtained by the method of the present invention is (0.9±0.2)x10 -9 mol·m -1 ·s -1 MPa -1 Comparison of the hydrogen permeability values ​​obtained with similar data for other materials shows that the claimed material ranks third in hydrogen gas barrier among the polymer materials tested and is comparable to unplasticized PVC (see Technical Reference on Hydrogen Compatibility of Materials, C. San Marchi, Sandia National Laboratories, Livermore CA).

[0044] Measurement method

[0045] The hydrogen permeability of the membranes was measured in a sealed chamber with a separated gas space (Electrochem 25 cm 2 ; See Figure 2 External view of the room and Figure 3 A Viton gasket (trademark for fluoropolymer elastomer) was used as a seal.

[0046] Hydrogen was supplied to one side of the membrane at a rate of 80 ml / min, and air was supplied to the other side at a rate of 20-100 ml / min. The gas flow was regulated by a Bronkhorst EL-flow gas flow controller. The hydrogen concentration in the air flowing through the chamber was measured using a potentiometric sensor, which was calibrated daily within the hydrogen concentration range of 100-10000 ppm, with an air-hydrogen mixture flow rate of 100 ml / min to improve measurement accuracy. The permeability was calculated using the following formula:

[0047]

[0048] Where l is membrane thickness, S is membrane area, F is hydrogen flux, and ΔP is hydrogen pressure difference.

[0049] Comparison of properties

[0050] Table 2 presents the known strength properties of some materials compared with the applied material. The material proposed by the invention has a comparable resistance to hydrogen permeation, but significantly outperforms all analogs in terms of a combination of properties.

[0051] Table 2. Strength properties of materials

[0052]

Claims

1. Use of polymer materials obtained by thermal radiation treatment of polytetrafluoroethylene blanks, wherein they are treated with high-energy ion radiation in an oxygen-free environment at a temperature strictly above the melting point of the polymer crystalline phase to an absorbed dose of 0.5-500 kGy, during the irradiation, the polymer temperature drops by no more than 0.5°C / 10 kGy, and after the ion radiation treatment, the polymer is thermally treated to manufacture products for the generation, transportation, storage, separation and containment of hydrogen.

Images