At present, hydrogen energy is regarded by many people as the ultimate energy in the 21st century, because of its high calorific value, clean and pollution-free, and its combustion value is known to be second only to nuclear fuel and three times that of gasoline.
So why is hydrogen energy an ideal clean secondary energy? First of all, what is secondary energy?
The energy and resources that can be obtained directly in nature without any processing are primary energy, including raw coal, crude oil, natural gas, solar energy, water power, etc. The difference between secondary energy and primary energy is that it is not directly taken from nature, but has It is obtained by converting primary energy after processing, so in a strict sense, it cannot be called "energy", but should be "secondary energy". No matter how many times the primary energy is converted to another energy, it is called secondary energy, which is more efficient, cleaner and more convenient than primary energy.
Why is hydrogen an ideal secondary energy source?
Hydrogen is produced by using other energy sources through certain methods, which is different from coal, oil, natural gas and other energy sources that can be directly mined, so from this point of view, hydrogen is a secondary energy source.
1. From the environmental point of view
The need to accelerate hydrogen uptake has never been stronger, as highlighted in the world's largest climate change report on August 9. The Natural Science Foundation has issued a warning that global warming levels could rise by more than 1.5°C above pre-industrial levels over the next 20 years, and hydrogen is a potential indicator of combating global warming.
2. In terms of preparation
Hydrogen exists mainly in the form of compounds in water and fossil fuels on earth, and it is named as gray hydrogen, blue hydrogen and green hydrogen according to different production sources and emissions during production.
Grey hydrogen is produced by burning fossil fuels such as coal, oil, natural gas, etc. During this process, carbon dioxide is produced, and it is currently the world's largest hydrogen production, but there will be pollution, which runs counter to the goals of carbon neutrality and carbon peaking. Therefore, the production of grey hydrogen will be reduced in the future;
Blue hydrogen is made from natural gas by reforming steam methane and self-heating steam. Although greenhouse gases are also generated during this process, low emissions are achieved due to the use of advanced technologies such as carbon capture and utilization to capture greenhouse gases. production, but recent research by researchers at Cornell University and Stanford University shows that hydrogen made from natural gas is dirtier than burning natural gas directly, and its carbon footprint is necessarily as much as 60 percent higher than that of diesel heating. In the process of extracting natural gas, 3.5% of the natural gas carrying methane leaks into the atmosphere, and the impact of methane on the greenhouse effect is 86 times that of carbon dioxide. So in this case, blue hydrogen is part of the transition and green hydrogen may be the main direction of future research;
Green hydrogen is hydrogen produced by using renewable energy sources such as solar and wind power, and in the process, carbon emissions can be net-zero. The current application is mainly in the electrolysis of water to produce hydrogen. Countries around the world are currently emphasizing the importance of green hydrogen to improve the global climate and environment. Green hydrogen is an important research direction in countries around the world, so green hydrogen is an ideal clean secondary energy.
