Safe production and utilization of hydrogen energy under the background of carbon neutralization
1、 Hydrogen energy development on double carbon target
What is carbon neutralization? The concept of carbon neutralization is actually a balance, that is, the carbon emitted by human activities is balanced with the carbon consumed, and carbon dioxide is discharged into the air. What are the ways? We see its importance and urgency. The Paris Agreement in 2015 has raised the problem of carbon neutralization, which controls the global steady temperature rise within 2 degrees before industrialization, and tries to control it within 1.5 degrees. In 2050-2100, the global goal of "carbon neutralization" is achieved, namely, the balance between emission and absorption of greenhouse gases. China will improve its national independent contribution. To reach the peak by 2030 is "carbon peak", and to achieve "carbon neutralization" in 2060. This is China's promise to the world. That is, we do not need to achieve carbon neutralization by 2100 and in 2060, it will reflect the responsibility of a great country. In such a big context, since this year, "double carbon" has been very hot on this land in China. What are the ways to achieve carbon neutralization? The first is that through carbon compensation mechanism, carbon emission is equivalent to the carbon emission reduced in other places, such as afforestation and purchase of renewable energy certificates. Second, the realization of low-carbon or zero carbon emission technology involves wind and solar energy. Photovoltaic has been down the road in the previous years. Recently, photovoltaic has begun to develop vigorously, which means that sustainable energy such as wind energy or solar energy should be adopted to achieve carbon neutralization. Third, through carbon trading, this is a very important concept, what is the concept of carbon trading? The factory must buy this indicator to produce, which will generate 300 trillion business opportunities.
Why do we achieve carbon neutralization? There are about 1.7 billion fuel vehicles in the world. The carbon dioxide emitted to the atmosphere every year is about 400 trillion tons. It is not only carbon dioxide, but also carbon monoxide and sulfur dioxide. Therefore, it poses a very big threat to human beings, so we need to use sustainable energy. The most important part of sustainable energy is hydrogen energy. In the future, the sustainable energy of mankind is mainly solar, wind, hydropower, biological and geothermal energy. However, these energy have a relationship with climate. For example, there is solar power generation today and less electricity will be generated in the cloudy day tomorrow. Therefore, it is related to climate. Therefore, energy storage technology needs to be developed, How to make energy platform can enter the large power grid. So there is an important direction to convert electricity into electrolytic water to produce hydrogen gas for storage. I say solar energy and wind energy are developing fast. If energy storage can not keep up with the limit, it will be very big. The future energy is solar, wind and hydropower. Hydrogen is produced by electrochemical method. The hydrogen produced is either to drive our cars by fuel cells. This is also a very important aspect of the rapid development of fuel cells.
Carbon neutralization and hydrogen energy development have become an international consensus. The main reason is that the low carbon clean and sustainable energy model has become an international consensus. Hydrogen energy is the most important factor to realize carbon neutralization and carbon peak. We can see that the current momentum of hydrogen energy development in the world is very strong. As of December 2020, 16 of the 27 major developed countries in the world have formulated comprehensive national hydrogen energy strategies, and 11 are in the process of formulating them.
Hydrogen energy utilization is an inevitable trend in the future. Why? All countries in the world try to solve the energy security problems in the future by developing hydrogen energy and grasp the commanding point in the field of international energy. The Research Report on the future development trend of hydrogen energy released by the international Hydrogen Energy Commission predicts that by 2050, the demand for hydrogen energy will be 10 times higher than that of the current one. It is conservative to expect that by 2030, the global hydrogen fuel cell passenger vehicles will reach 10million-15million, which is conservative estimates, and I hear a report saying it may reach 30million.
The challenge of hydrogen. First, the technology of hydrogen preparation, storage and utilization is not perfect; Second, the price of hydrogen is relatively high; Third, hydrogen cannot be liquefied under any pressure at room temperature, which brings great difficulties to transportation and storage; Fourth, hydrogen is easy to leak (the smallest molecule, easy to penetrate many filling materials); Fifth, low energy ignition, a Mars can make it explode; Sixth, the range of ignition points of hydrogen air mixture is wide, not that hydrogen can ignite when it reaches a certain amount, or it can be ignited and exploded at 17%; In addition, brittle metal materials. The biggest advantage of hydrogen is that the energy density is high. It can be seen from the comparison of different energy storage materials that hydrogen is about 140.4 joules per kilogram, much higher than lithium battery gasoline. Gasoline is 43 at present, and the energy density of hydrogen is more than three times of that of gasoline. Therefore, high energy density is the basis for realizing industry and has the basis of rapid development, Why is lithium battery not developing so fast? It is that the energy density can not reach the required range at present, but hydrogen fuel cell is easy to reach the range. We just said that hydrogen has problems, it has its advantages, and I list six advantages. Hydrogen energy is a clean energy without pollution; Second, it has a wide range of sources, which can be obtained from water electrolysis or fossil fuel electrolysis; Third, the combustion heat value or energy density is high; Fourth, there are many forms of utilization; Fifth, energy can be stored. Although it can not be turned into liquid at room temperature, high pressure storage and irrigation can also be stored; Sixth, the relative safety is better than that of gasoline. Hydrogen is mainly used in three fields. First, chemical raw materials, 38% for refining and coal deep processing, 60% for ammonia synthesis; Second, the biggest opportunity in the future is hydrogen fuel cell vehicles; Third, the distributed generation system of small hydrogen fuel cell is now advocated for micro grid. Because of the development of hydrogen energy, micro grid is now a fashionable concept, so that distributed power generation system can meet the domestic heat system. Hydrogen manufacturing method. It includes three main links: hydrogen production, hydrogen storage and hydrogen use. Currently, hydrogen production mainly comes from fossil fuels, 95-96% of which are through pyrolysis or other processes of natural gas, of which only 4% are electrolytic water. In 2030, China's hydrogen production will reach 5million tons / year; In 2060, China's hydrogen production will reach 100 million tons, of which the proportion of hydrogen produced by electrolysis water will reach 80% in the future, and the hydrogen production in the future will be basically electrolytic water. This is the manufacturing method of hydrogen. Eight methods are listed here, including electrochemical method, water gas conversion method, cracking method, etc. the most important last high temperature hydrogen production method is to use solar energy, which has a very important focusing mirror, focusing on a very hot point, 1500 degrees. In this case, add catalysts such as iron catalyst, After water injection, it can be directly converted into hydrogen and oxygen. This method is also a very important method in the future development besides the method of electrolysis water to produce hydrogen.
Hydrogen production process includes high temperature cracking of hydrocarbons. The second method is electrochemical water decomposition, which is the future technology. There are five aspects of hydrogen production from electrolytic water, mainly four technologies. It is not detailed. This is the biggest task facing mankind in the future. Solar energy directly shines on the catalyst to produce decomposition water, which is a major topic in the future.
2、 The safety utilization of hydrogen energy
We should know the danger of hydrogen scientifically and make reasonable safety measures for hydrogen use. I just said that one is that the physical and chemical properties of hydrogen determine the safety of hydrogen. What we talk about is the leakage and diffusion, combustion explosion and light embrittlement. The leakage and diffusion of hydrogen is about 2.83 times of methane, and the diffusion speed is very fast, but it also causes a good direction is to burn off very quickly when burning, and it is rising in the air, not spreading combustion, and has advantages over gasoline or natural gas when burning. Let's look at the combustion and explosion of hydrogen. The first one is very fast, the second is the wide range of combustion, the wide range of ignition, and the third is the extremely low ignition energy, which are all dangerous factors. Let's look at the explosive energy of hydrogen is a small volume explosion, which is very low, about one-22 of the gasoline explosion, and from this point of view it may be safer than gasoline. We look at its harm. The first is hydrogen embrittlement. The smallest molecule can penetrate any metal container, causing the container to crack and explode. I don't share it in detail because of the time relationship. This is a radar image, and the blue color is hydrogen. From this diagram, we can see that the safety of hydrogen is relatively safe compared to gasoline or other fuel. Hydrogen energy transportation is that low temperature liquid hydrogen storage can be transported by vehicles, high pressure hydrogen tanks are used for high temperature gas storage, and there are three main ways of hydrogen storage of materials.
The three principles of safe utilization of hydrogen energy are: no leakage, early detection and no accumulation.
This is a case study in Japan. They have formulated the high pressure gas security law, which includes a series of measures, such as supporting the research of hydrogen energy safety technology, design, manufacture and safety testing of high pressure hydrogen storage bottle, safety performance evaluation test of equipment and materials of high-pressure hydrogen system, and safety technical measures of hydrogenation station. As you may know, Mr. Li visited the car in Japan. The hydrogen tank of this car is guaranteed. There are two hydrogen tanks in this hydrogen tank and ten such hydrogen tanks in the bus, which can guarantee the mileage of 500-700 km. We also have plans for the construction of hydrogen safety technical standards system and increase the investment in science and technology; Speed up the revision and improvement of the hydrogen energy safety standard system for vehicles; Attention should be paid to the construction of 70MPa hydrogen related equipment manufacturing system. The efforts of hydrogen vehicles in this regard are three aspects: developing fuel cell vehicle technology and developing fuel cell vehicles are the important technical route of new energy vehicles; Second, hydrogen energy is listed as energy for the first time. Before, hydrogen is a dangerous product, and dangerous goods cannot be used on a large scale. Now, if hydrogen energy is listed as energy, it can be used on a large scale; Third, fuel cell vehicles are explicitly included in consumer subsidy products, such as you produce fuel cell vehicles, and the state grants subsidies. This is very important. A series of standards have been issued by the state and local governments. Hydrogen tank is the best way to store hydrogen. This is a Japanese air storage tank with 70 atmospheric pressure. Such a gas tank can store 5kg of hydrogen. This can make the car run 500-700 km of mileage on the car. This is a photo of the hydrogen tank. In order to prevent safety problems, there are many facilities in the hydrogen tank to prevent leakage. The hydrogen tank is a three-layer structure, with aluminum alloy or stainless steel in the middle. It is wrapped by carbon fiber outside, which can ensure 700 atmospheric pressure will not explode, even when colliding. There are several aspects of the overall safety of fuel cell vehicles: firstly, people lack of understanding about hydrogen fuel; The second is that hydrogen explosion is a reduction of volume; Third, the explosive energy of gasoline is 22 times that of hydrogen of the same volume gas; Because the density of hydrogen is far lower than that of air, even if it is going up after leakage, for example, this figure shows that gasoline explosion will burn, and hydrogen explosion is upward like an electric welding gun. Moreover, the state has passed explosion test to prove that hydrogen fuel cell is more safe than gasoline vehicle; The last hydrogen fuel cell meets the national collision safety standards, so the development of hydrogen fuel cell has its safety foundation.