Current situation and future development trend of hydrogen technology

one Hydrogen energy background and significance

Looking back at the forms of energy consumed by human beings, such as drilling wood for fire in ancient times, coal used in the farming era, oil and natural gas applied on a large scale in the industrial era, people continue to develop and use new clean energy, compared with solar, wind and water energy is usually limited by geographical location and season, and nuclear energy leakage will also bring serious environmental problems. Hydrogen energy enters people's vision due to its advantages of high combustion calorific value, sustainability, abundant reserves and zero pollution, and the development of hydrogen energy can achieve real green, clean and sustainable development. At present, China's carbon peak, carbon neutral development goal proposed, will further speed up the process of carbon reduction. Hydrogen is gaining more and more attention as a zero-carbon energy carrier: 20% of the world's CO2 emissions can be replaced by hydrogen in 2050, and hydrogen consumption will account for 18% of the world's energy market.

The national key research and development Plan in 2021 launched the implementation of the "hydrogen energy technology" key special project, the goal is to energy revolution, transportation power and other major needs as traction, by 2025 to achieve China's hydrogen energy technology research and development level into the international advanced ranks, the key industrial chain technology independent and controllable, describing the goal vision of China's hydrogen energy industry development technology path. In the "Hydrogen energy Technology" key special guide, 19 guide tasks such as "photovoltaic/wind power and other wave power electrolytic hydrogen production materials and process basis" are planned to be launched around the four technical directions of hydrogen energy green production and scale transfer storage system, hydrogen energy safe storage and rapid transmission and distribution system, hydrogen energy portable transformation and efficient power system, and comprehensive demonstration of "hydrogen into 10,000".

two Upstream hydrogen production technology route

Although hydrogen is the most abundant element on Earth, the free hydrogen in the natural state is relatively scarce, so a certain hydrogen production technology is needed to prepare hydrogen from hydrogen-containing raw materials on a large scale to meet the growing demand for hydrogen. At present, the main hydrogen production technology routes are as follows:

1. Hydrogen production from fossil energy reforming

At present, the most common method of hydrogen production in China is the chemical reforming technology of fossil fuels based on coal and natural gas. Coal hydrogen production is mainly divided into two ways: coal coking and coal gasification. Coal gasification technology to produce hydrogen is one of the most important methods of hydrogen production in China. Coal gasification to produce hydrogen is to gasification coal and gasification agent under certain conditions of temperature, pressure and other conditions under biochemical reaction and gasification into gaseous products with hydrogen and CO as the main components, and then through CO transformation, separation, purification and other processing to obtain a certain purity of product hydrogen, the technology is mature and efficient. Lower cost; Natural gas hydrogen production technology mainly includes: steam conversion method, partial oxidation method, catalytic cracking method, methane autothermal catalytic reforming method, etc., of which steam conversion hydrogen production is more mature, and it is also widely used in other countries. However, the hydrogen production technology of fossil energy reforming consumes limited reserves of fossil fuels, which can not get rid of the dependence on traditional energy sources, and will also cause environmental pollution.

2. Electrolysis of water to produce hydrogen

Water electrolysis hydrogen production technology mainly includes alkaline water electrolysis cell (ALK), proton exchange membrane water electrolysis cell (PEM) and solid oxide water electrolysis cell (SOEC). So far, the industrial large-scale electrolysis water hydrogen production is basically the use of alkaline water electrolytic cell hydrogen production technology, but its power consumption is large, the cost of hydrogen production is high.

Proton exchange membrane water electrolyzer (PEM) : No liquid electrolyte is required, which greatly simplifies the design process. The electrolyte is acidic polymeric film. The main disadvantage of this technology is the limited life of the diaphragm. Unlike alkaline electrolysis, thin film electrolysis is safer because there is no electrolyte (due to higher density and higher operating pressure, more rigorous design is required). Due to the high relative cost, small capacity, low efficiency and short service life, the thin film electrolysis method is not as mature and available as the alkaline electrolysis method, and further improvements in raw materials and battery stack design are needed to improve performance.