What is the strategic position of artificial hydrogen production and hydrogen industry in China?

1.2.1 Industrial hydrogen production is regional

The Asia-Pacific region leads the world in industrial hydrogen production, followed by North America (Figure 4). In 2017, the production scale of industrial hydrogen in Asia Pacific was $107.136 billion, North America was $55.580 billion, and Europe was $51.757 billion. Rapid economic growth in developing countries such as China and India has led to strong demand for clean energy such as hydrogen energy in the Asia-Pacific region.

China's demand and production of industrial hydrogen is strong, showing an increasing trend year by year, and currently maintains a balance between supply and demand, and both demand and production rank first in the world. As a major country in the use of hydrogen energy in the world, China has maintained the first place in the world for 9 consecutive years since its production exceeded 1 000×104 t in 2009 (Figure 5).

1.2.2 Hydrogen production from fossil resources is dominant

At present, artificial hydrogen production raw materials are mainly fossil resources such as oil, natural gas and coal. Compared with other hydrogen production methods, the hydrogen production process of fossil resources is mature, and the raw material price is relatively low, but it will emit a lot of greenhouse gases and pollute the environment.

In 2017, more than 96% of the world's major artificial hydrogen production feedstock was derived from thermochemical reforming of traditional fossil resources, and only about 4% was derived from electrolytic water (Figure 6). Coal and natural gas are the main raw materials for artificial hydrogen production in China, accounting for 62% and 19% respectively (Figure 7). Hydrogen production by electrolysis of water occupies a special place in the Japanese hydrogen industry, and its capacity for hydrogen production by brine electrolysis accounts for 63% of the total capacity of all artificial hydrogen production in the country.

1.2.3 Hydrogen production from coal gasification has great development potential

The gasification of coal refers to the reaction of coal and gasification agent into gas products under the condition of high temperature and atmospheric pressure or pressure. With the development of coal-to-syngas and coal-to-oil industries, the production of coal-to-hydrogen has increased year by year, with a large scale and low cost, and the cost of hydrogen production is about 20 yuan /kg. In addition, in the production process of chemical products (including synthetic ammonia, methanol, etc.), the recovery of industrial hydrogen with purity greater than 99% from hydrogen-containing relaxation gas is also increasingly mature and increasing.

Underground coal gasification for hydrogen production has great development potential and is also an effective way to clean coal transformation and utilization. Coal underground gasification hydrogen production technology has the advantages of high resource utilization rate and less surface environmental damage, which conforms to the resource structure characteristics of "rich coal, poor oil and little gas" in China, but this technology is still in the exploration stage, and there is a long distance from commercial utilization.

1.3 Efficient hydrogen storage and transportation technology is the focus of development

Safe and efficient hydrogen storage and transportation technology is the key to realizing the practical application of hydrogen energy [6-7]. Hydrogen energy storage methods mainly include low temperature liquid hydrogen storage, high pressure gaseous hydrogen storage, solid hydrogen storage and organic liquid hydrogen storage, etc. Different hydrogen storage methods have different hydrogen storage densities, among which gaseous hydrogen storage mode has the smallest hydrogen storage density, and metal hydride hydrogen storage mode has the largest hydrogen storage density (FIG. 8).

1.3.1 Low temperature liquid hydrogen storage cost is high

The large-scale and cheap production, storage and transportation of industrial hydrogen is the basis of realizing the practical utilization of hydrogen energy. Gaseous hydrogen is liquid at -253 ° C, and the density of liquid hydrogen is 845 times that of gaseous hydrogen. The weight ratio of liquid hydrogen storage is between 5.0% and 7.5%, and the volume capacity is about 0.04 kgH2/L. Hydrogen liquefaction is expensive and energy consuming (4 to 10 kWh/kg), accounting for about one-third of the cost of liquid hydrogen production. Liquid hydrogen storage vessels need to have very high insulation capacity to avoid boiling of liquid hydrogen.

At present, liquid hydrogen is mainly used as the fuel of space rocket propulsion, and its storage tank and trailer have been applied in China's aerospace and other fields. With the development of the human space program, liquid hydrogen storage vessels are becoming larger, and it is now possible to build large liquid hydrogen adiabatic storage tanks with storage capacity of more than 1,000 m3.

1.3.2 High pressure gaseous hydrogen storage technology is mature

High-pressure gaseous hydrogen storage is the most commonly used and mature hydrogen storage technology at present, and its storage method is to compress industrial hydrogen into a high-pressure vessel [8]. The high pressure gaseous hydrogen storage device mainly includes fixed hydrogen storage tank, long tube cylinder, long tube bundle, cylinder group and vehicle hydrogen storage cylinder. The steel cylinder is the most commonly used high-pressure gaseous hydrogen storage vessel, which has the advantages of simple structure, low energy consumption for compressed hydrogen preparation, fast filling and discharge speed, etc., but there are some shortcomings such as poor safety performance and low volume specific capacity. At present, the hydrogen refueling stations that have been built and are under construction in China generally use long tube cylinder group hydrogen storage equipment.