Market and product

A fuel that produces no GHG emissions, and that can produce electricity cheaply and on demand, seems almost too good to be true, but hydrogen meets all these criteria

The COP21 Paris Sustainable Innovation Forum, held in December 2015, set targets for the reduction of greenhouse gas (GHG) emissions, which are seen as a primary cause of climate change. The forum has helped set the world firmly on a path toward a low-carbon society, where CO2-producing fossil fuels are no longer used. Renewable sources of energy such as wind and solar power produce no GHG, and have attracted tremendous attention and investment. Hydrogen, which does not produce CO2, but only pure water, when used to generate power, is a prime contender as an alternative to fossil fuels.

Since the wind does not always blow and the sun does not always shine, there is a need to store the energy produced by wind turbines and solar panels. One way of creating a stable energy supply from these renewable sources is the production and storage of hydrogen , which can then be used to produce a steady supply of carbon-free energy, usually in the form of electricity.

For hydrogen to be widely used as a practical fuel, there are three factors that need to be addressed: production; storage and distribution; and utilization. All of these require innovation and new materials in order to make the fullest use of this energy source and bring about a “hydrogen society.” Toray’s contributions extend beyond the development of fuel cell vehicles (FCVs)—perhaps the most visible form of hydrogen fuel usage today—and encompass the entire hydrogen infrastructure, from the production, storage and transportation of the fuel, to its use in FCV fuel cells and other applications.

How hydrogen can power cars

A fuel cell combines hydrogen and oxygen to produce electricity, which can then be used to drive a motor, or be stored in batteries for future use. Such a system employed to power a vehicle produces only water as the exhaust product. Fuel cells are also becoming available for home use, allowing households to generate their own electricity.

Japan’s Toyota Motors has produced the first commercially available fuel cell vehicle, the Mirai, and Toray has been involved in the development of this vehicle in a variety of ways.

In order to store enough hydrogen to power the vehicle, the fuel must be stored under great pressure. The Mirai’s triple-layer tanks store the gas at a pressure of 70MPa (10,000 psi, or 700 atmospheres), approximately the same pressure that deep-sea submersibles experience four miles below the ocean’s surface– close to twice the depth of the ocean where the Titanic sank.

Such a tank must obviously be extremely strong, but enhanced strength implies a corresponding gain in weight, so a lightweight alternative to metal must be used for this purpose. In this case, that is carbon fiber. Toray, with long experience with this material, which possesses one-quarter the weight of steel and ten times the strength, provides the carbon fiber used to construct these tanks, resulting in significant weight savings when compared to metal tanks of the same strength.

Over the years, Toray has continually worked to improve the strength of its carbon fiber, by eliminating defects of ever-decreasing size. In 1980, micron-sized (one-millionth of a meter) defects could be screened and eliminated. Now, defects less than a thousandth that size (one-billionth of a meter, or one nanometer) can be detected, making the fiber even stronger. To show just how small a billionth of a meter actually is, Toray provides the example of the distance between London and Paris—some 340 kilometers; one-billionth of this distance is just 3.4 millimeters, or about the size of a grain of wheat. Accuracy and precision is obviously of prime importance when producing such components as high-pressure hydrogen tanks, where a flaw in the material could have catastrophic consequences.

Fuel cells work by using a catalyst to split hydrogen into ions (protons) and electrons. The protons pass through a polymer electrolyte membrane (PEM), and the electrons pass along a circuit, producing an electric current. The protons and electrons then meet again and combine with the oxygen in the air, forming water.

A key component is the electrode substrate of the fuel cell assembly. Over the past 30 years, Toray has developed a carbon paper that incorporates carbon fiber and meets the requirements for such a material, providing the appropriate amount of gas diffusion and durability, and this product, used in fuel cell vehicles, now enjoys a leading global market share.

Toray’s expertise and experience with polymer chemistry also finds another use in fuel cells, where the use of its carbon fiber in the catalyst-coated membranes increases the maximum output power of the cells.

The fuel cells of FCVs, as well as the fuel cell packages for home electricity generation and other applications, widely utilize Toray materials, and the company’s innovations also apply to the extraction and storage of hydrogen to stabilize the variable output from renewable energy sources. Here, high-pressure compressors are required, and Toray’s experience with materials of all kinds is helping to realize such hydrogen infrastructure as a reality.

As well as its expertise in carbon fiber, Toray has also gained specialist knowledge through its acquisition of companies. The German company SolviCore GmbH & Co. KG, 100 percent of whose shares were purchased by Toray in summer 2015, was established in 2006 for the purpose of developing, manufacturing and distributing catalyst-coated membrane (CCM) and membrane electrode assembly (MEA) materials, where electrode base material and electrolyte are combined.
Tomorrow’s hydrogen society – today

In Hamburg, Germany, hydrogen is already being used to power a fleet of city buses, as part of the nation’s Clean Energy Partnership initiative. The German federal government announced some years ago that 50 hydrogen fueling stations would be opened by 2015, serving some 5,000 FCVs nationwide. The number of filling stations is planned to expand to 400 by 2023, at a cost of about €350 million ($380 million).

Similar moves are afoot in some areas of the USA, notably California, where interest in a hydrogen society seems greatest, particularly in the Los Angeles area.

In Toray’s native Japan, the hydrogen society is being enthusiastically promoted. At the COP21 meeting, Japanese Prime Minister Shinzo Abe stated: “The key to acting against climate change without sacrificing economic growth is the development of innovative technologies. To illustrate, there are technologies to produce, store and transport hydrogen toward realizing CO2-free societies …. By next spring Japan will formulate the ‘Energy and Environment Innovation Strategy.’ Prospective focused areas will be identified, and research and development on them will be strengthened.”

Additionally, Yoichi Masuzoe, Governor of Tokyo, is keen to promote a hydrogen society . Masuzoe presides over a powerhouse of economic and industrial activity and a population equivalent to that of some medium-sized European countries, and he has expressed his wish to create a hydrogen infrastructure in the metropolis over the next few years.

All around the world, in North and South America, Europe, the Asia-Pacific region and in Africa, there are moves toward an envisioned “Green Innovation” society, which often includes hydrogen as a key part of the mix. Toray, with its experience in a wide range of advanced, innovative materials, is helping to change the world and make positive contributions for a better future society .