3. Hydrogen Energy Industry Chain

3.1 Overall Situation of the Hydrogen Energy Industry Chain

Hydrogen energy is a clean secondary energy source and an important carrier for China's energy transformation. It has been officially included in China's energy strategy system. The hydrogen energy industry chain is mainly divided into three major links: upstream hydrogen production, midstream storage, transportation and distribution, and downstream applications. Each link involves a variety of process routes, and a large number of technologies are still in the early stages of commercialization.

3.2 The Application and Market Situation of Major Petrochemical Materials in the Hydrogen Energy Industry Chain

In 2022, the overall material demand for China's hydrogen energy industry chain is about 6741 tons; The hydrogen storage and transportation process requires the most petrochemical materials, accounting for approximately 99% of the total material demand. The key petrochemical materials in the hydrogen energy industry chain mainly include proton exchange membranes and carbon fibers.

3.2.1 Petrochemical Materials in the Production Process

At present, more than 80% of hydrogen in China is produced from various fossil materials, with less than 1% produced by electrolysis of water, and the rest coming from industrial by-product hydrogen; In the long run, hydrogen production from fossil fuels will still exist and will be combined with CCUS and other sources to become the main source of blue hydrogen. At the same time, the share of hydrogen production from electrolysis of water will be significantly increased; The share of traditional industrial by-product hydrogen will slightly decrease.

There are three main technical routes for hydrogen production through electrolysis of water: alkaline electrolysis (AWE), proton exchange membrane (PEM) electrolysis, and solid oxide (SOEC) electrolysis. In addition, anion exchange membrane (AEM) technology has become one of the emerging research and development technologies due to its low cost, simplicity, and efficiency. In recent years, PEM electrolytic cell installation has been the main type of new electrolytic cell installation worldwide.

The main components of PEM water electrolysis battery are membrane electrode (MEA), collector (gas diffusion layer), and separator. The most commonly used membrane is perfluorosulfonic acid polymer membrane, and the sealing gasket is generally made of EPDM as the main body, using fluorine resin composite and other methods as the shell, and requiring special adhesive to bond the sealing gasket. In 2022, the demand for proton exchange membranes in electrolytic cells in China is about 0.3 tons, and the demand for EPDM sealing gaskets is about 0.2 tons; It is expected that the two will increase to 106 tons and 47 tons respectively by 2030.

In addition to being used for industrial hydrogen separation, a large amount of hydrogen/natural gas mixed transportation pipeline terminals require hydrogen separation before they can be used. In addition to inorganic membrane materials, the basic materials for hydrogen separation membranes currently used in industrial applications are mainly polyamide, polyimide and polysulfone membranes, most of which require secondary modification or coating. There are mainly three global hydrogen separation technology suppliers, including Air Products, Liquid Air, and Ube Chemical, with most of their products reportedly having a lifespan of over 10 years. In 2022, the demand for membrane materials in China's hydrogen separation process is about 10 tons, including 3 tons of PSF membrane, 6 tons of PI membrane, and about 1 ton of PA membrane. It is expected that by 2030, the demand for membrane materials in the hydrogen separation process will increase to 15 tons.

3.2.2 Petrochemical Materials in the Storage and Transportation Process

At present, the main storage methods for hydrogen energy include high-pressure gaseous hydrogen storage, low-temperature liquid hydrogen storage, and solid-state hydrogen storage. Among them, high-pressure gaseous hydrogen storage is widely used and the most mature technology, so lightweight and high-pressure hydrogen storage tanks are the key. The market demand for in vehicle hydrogen storage cylinders is influenced by factors such as the application vehicle model, hydrogen storage cylinder volume, hydrogen storage cylinder pressure, and the number of cylinders in a single system. In 2022, the demand for hydrogen storage bottles in China is about 74000, mainly 35MPa/140L. In the future, there will be a trend for domestic hydrogen storage bottles to shift towards large capacity, multiple bottle groups, and high pressure.

At present, the demand for high-end materials for hydrogen storage bottles in China is less than 10000 tons, of which 70% of carbon fiber relies on imports, mainly from companies such as Dongli in Japan, Dongbang in Japan, and SK in South Korea; The T700 model products from domestic carbon fiber manufacturers have relatively stable performance and have gradually been used in hydrogen storage bottles in China. According to estimates, in 2022, the demand for hydrogen storage bottle materials for vehicles in China is about 6716 tons, and it is expected to increase to 78883 tons by 2030.

At present, most hydrogen refueling machines in domestic hydrogen refueling stations are 35MPa, and the core components of 70MPa products are mostly imported. Hydrogen refueling guns and pipelines are also mostly imported products. The petrochemical materials used in hydrogenation machines, except for a small amount of sealing components (mostly FKM), are mainly used in hydrogenation pipelines. Among them, the hydrogenation gun pipeline is generally composed of 6-8 layers, with the inner layer mostly made of POM material, and materials such as EVOH, PEN, PA6, PA66 can also be used. The outer layer is mostly made of PA material, and materials such as maleic acid modified PP and PE, PPS, PA6T can also be used. By the end of 2022, China has built and operated 358 hydrogen refueling stations. According to the plan, there will be around 1000 stations by 2025 and 5000 stations by 2030; In 2022, China will use approximately 0.4 tons of non-metallic materials for hydrogenation gun tubes, and it is expected to increase to 3 tons by 2030.

3.2.3 Petrochemical Materials for Hydrogen Fuel Cells

Hydrogen fuel cells are generally divided into six categories, with PEMFC as the absolute mainstream, accounting for over 80% of the shipment volume, while SOFC and PAFC each account for about 10%. Fuel cells are mainly used in applications such as vehicle mounted, fixed power stations, and portable power sources, with vehicle mounted demand accounting for approximately 80% of the total demand for PEMFC.

The working principle of hydrogen fuel cells is that hydrogen is decomposed into electrons and hydrogen ions (protons) through the catalyst (platinum) in the negative electrode of the fuel cell. Among them, protons reach the positive electrode through a Proton Exchange Membrane and react with oxygen to generate water and release heat, while electrons flow from the negative electrode to the positive electrode through an external circuit to generate current. Membrane electrode assembly (MEA) is an important component of hydrogen fuel cell stack, mainly composed of carbon paper, catalytic layer, and proton exchange membrane.

Carbon paper is a composite material of porous carbon fibers and carbon that has been heat-treated at high temperatures, typically consisting of short cut fibers. At present, China is unable to produce carbon paper with a carbon fiber content of over 60%. According to the mainstream thickness and carbon paper density in the market, China's MEA carbon paper materials will be approximately 6 tons in 2022, and it is expected to increase to 89 tons by 2030.

Perfluorosulfonic acid membrane (PFSA) is the most commonly used commercial proton exchange membrane. The proton exchange membranes used in on-board hydrogen fuel cells are mainly Gore Select series membranes from Gore Company, with a thickness of 5-12μM. The proton exchange membrane is a three-layer structure when it leaves the factory, which includes an upper protective membrane, a lower protective membrane, and a proton exchange membrane in the middle. The upper and lower protective films are both specially treated low ash disposable polyester protective films, and the two protective films need to be peeled off during use according to the current mainstream thickness in the market. In 2022, the demand for proton exchange membrane and protective membrane materials in China is approximately 4 tons and 26 tons respectively, and it is expected to increase to 59 tons and 414 tons respectively by 2030.

4. Conclusion

By 2030, China's new energy industry represented by wind, light, and hydrogen will grow at an average annual rate of about 20%, and the demand for high-end petrochemical materials will increase from over 2.3 million tons in 2022 to over 4.5 million tons. The photovoltaic industry is the largest consumer sector, accounting for over 80% of the total material demand; By product, EVA film and PET backplate film have the highest demand, followed by PVF film, POE film, EMC, and epoxy resin. Overall, the self-sufficiency rate of high-end petrochemical materials for new energy in China is currently 60% to 70%, and there is still significant room for domestic substitution. Petrochemical enterprises should increase the research and development of relevant materials, especially key materials with high demand potential that constrain industry development, in order to accumulate strength for China's energy to diversify, clean, and green development.