Four major application prospects of hydrogen energy

 

The development and utilization of hydrogen energy is one of the important ways to achieve the goal of carbon neutrality faster, ensure national energy security, and achieve low-carbon transformation. Hydrogen energy is currently mainly used in the fields of energy, steel metallurgy, petrochemical industry, etc. With the rapid development of top-level policy design and hydrogen energy industry technology, the application fields of hydrogen energy will be diversified and expanded, including energy storage, fuel, chemical industry, steel, etc. Applications in metallurgy and other fields will surely become more and more widespread.

 

  Hydrogen energy storage

 

my country is rich in renewable energy resources and should vigorously develop wind energy and solar photovoltaic power generation to convert renewable energy into hydrogen energy. However, the intermittency and randomness of wind power and photovoltaic power generation affect the continuity and stability of their grid-connected power supply, and also weaken the peak load regulation of the power system.

 

Using wind power and photovoltaic power generation to produce green hydrogen can not only effectively utilize abandoned wind and light, but also reduce the cost of hydrogen production; it not only improves the flexibility of the power grid, but also promotes the consumption of renewable energy. In addition, hydrogen energy can also serve as the hub of the energy Internet, integrating renewable energy with power grids, gas grids, heat grids, and transportation networks to accelerate the energy transformation process.

 

  hydrogen fuel

 

Hydrogen energy can be used in the power industry as a terminal energy source, converting chemical energy into electrical energy through hydrogen fuel cells, or converting chemical energy into kinetic energy through gas turbines. Hydrogen fuel cells have the advantages of high energy density, high energy conversion efficiency, and zero carbon emissions. They mainly include proton exchange membrane fuel cells and solid oxide fuel cells.

proton exchange membrane fuel cell
It is mainly composed of membrane electrodes, bipolar plates, electrolytes and external circuits. It has the advantages of low operating temperature, fast start-up, wide power range and strong stability, and has developed rapidly in the field of automotive power supply. As a key component of fuel cells and electrolyzers, proton exchange membranes need to have the characteristics of small proton conduction resistance, high current density, and high mechanical strength. The limitation of this type of membrane is that it is prone to chemical degradation, and the increase in temperature changes the proton conductivity. Bad, the cost is also higher.

 

solid oxide fuel cell
It is an all-solid-state power generation device, consisting of anode, cathode, electrolyte, sealing material and connecting material. Among them, the electrolyte determines its operating temperature and power and is the core component. Although it is limited by the high operating temperature of 600 to 1000°C and low starting speed, it has broad development prospects due to its wide range of fuel selection, high energy conversion efficiency, and no need for catalysts.

 

Hydrogen gas turbine
Gas turbines are internal combustion power machines that convert the chemical energy of fuel into kinetic energy. They are core equipment in the fields of power generation and ships. Compared with coal-fired generating units, gas turbines have the advantages of high power generation efficiency, low pollutant emissions, short construction period, small footprint, low water consumption and flexible operation adjustment. Currently, the power generated by gas turbine power stations accounts for approximately 23.1% of the world's total power generation.
In this regard, there is a big gap between my country and foreign countries. We need to strengthen policy support, deepen scientific research, and pave the way for the localization of hydrogen gas turbines as soon as possible.

 

  Hydrogen chemical raw materials

 

Currently, about 55% of global hydrogen demand is used for ammonia synthesis, 25% is used for hydrogenation production in refineries, 10% is used for methanol production, and 10% is used in other industries. With the continuous development of my country's science and technology and industrial level, hydrogenation technology will be increasingly used in petrochemical fields such as petroleum refining.

 

Petrochemical hydrogenation
Hydrogenation technologies used in the petrochemical industry mainly include hydrocracking of heavy oil to produce aromatics and ethylene, hydrodesulfurization of residual oil to produce ultra-low sulfur fuel, hydroconversion of inferior catalytic diesel and gasoline to produce high-octane gasoline, and hydrogenation of C3 fractions. Depropyne and allene, hydrogenation of heavy aromatic hydrocarbons, hydrogenation of benzene to cyclohexane, etc.

Synthetic chemical products
Hydrogen is used as raw material to synthesize chemical products, such as ammonia, urea, etc. Ammonia is mainly synthesized through the Haber-Bosch process. It has a higher energy density than hydrogen and can be used to store energy and generate electricity without emitting carbon dioxide at all.
Ammonia can be stored as a liquid at room temperature and 10 atm, making it suitable for transportation. In addition, there is a complete infrastructure for transporting and processing liquid ammonia, which facilitates the large-scale utilization of ammonia. Ammonia can also be combined with CO2 to obtain urea, which is both an important nitrogen fertilizer and a sustainable hydrogen carrier. It is stable, non-toxic, environmentally friendly and easier to store.

 

synthetic fuel
Hydrogen can also be synthesized by reacting with carbon dioxide to synthesize simple carbon-containing compounds such as methanol, methane, formic acid or formaldehyde. These compounds are easy to store and transport after liquefaction, have high energy density, are not prone to explosion, and can achieve essentially zero carbon emissions as liquid fuels. They are a suitable renewable energy storage and transportation mode in addition to power transmission.

 

hydrogen reducing agent

 

During the steel smelting process, coke is used as a reducing agent for iron ore, which will produce a large amount of carbon emissions and a variety of harmful gases. As my country's second largest source of carbon emissions, iron and steel metallurgy urgently needs to develop deep decarbonization processes. Using hydrogen instead of coke as the reducing agent, and the reaction product is water, can significantly reduce carbon emissions and promote the transformation of clean metallurgy.

 

At present, some domestic steel companies have also released hydrogen metallurgy plans, built demonstration projects and put them into production. In the context of the "dual carbon" goal, the development of hydrogen energy steelmaking is urgent. In actual production, green hydrogen is the most suitable for steelmaking. If the production cost of green hydrogen can be reduced, the advancement of green metallurgy can be accelerated, and the environmental benefits obtained will eventually cover its additional costs. The use of hydrogen energy for steel metallurgy is the only way for the steel industry to achieve the goal of deep decarbonization.