Complete set of detailed information on hydrogen energy utilization

The utilization of hydrogen energy refers to the conversion of hydrogen energy into electric energy and heat energy for utilization.

Hydrogen energy is a kind of secondary energy, which is produced by natural gas reforming, electrolyzed water, solar photosynthesis, biological hydrogen production and other energy sources. Unlike coal, oil and natural gas, which can be directly mined from underground, it is almost completely dependent on fossil fuels.

Chinese name: hydrogen energy utilization mbth: hydrogen energy utilization advantages: safety and environmental protection application: extensive history: utilization direction since World War II: hydrogen energy utilization history, development status, hydrogen energy preparation methods, characteristics, hydrogen energy utilization safety issues, hydrogen energy utilization direction, prospect and hydrogen energy utilization history In the history of chemistry, people mainly attribute the discovery of hydrogen to the British chemist and physicist Cavendish (Cavendish, H./Kloc-0 But as early as16th century, the famous Swiss doctor's palace described that there was a gas produced when iron filings came into contact with acid. /kloc-in the 7th century, Helmont (J.B. 1579- 1644), a famous Belgian medical chemist, accidentally came into contact with this gas, but failed to separate and collect it. Although Boyle collected this gas by accident, he didn't study it. They only know that it is flammable and know little about it; 1700, French pharmacist Lhemery (n.1645-1715) was also mentioned in the report of the Paris Academy of Sciences. Cavendish was the first person to collect and study hydrogen, but Cavendish's understanding of hydrogen was not correct. He thinks that water is an element, and hydrogen is water with too much phlogiston. It was not until 1782 that lavoisier made it clear that water was not an element but a compound. 1787, he named this gas "hydrogen", which means "producing water", and confirmed that it was an element. Hydrogen as fuel for internal combustion engines is not a recent invention of mankind. Hydrogen has been used in internal combustion engines for a long time. The history of the first hydrogen internal combustion engine in human history can be traced back to 1807. A Swiss named Isaac de Levitz made a single-cylinder hydrogen internal combustion engine. He filled the cylinder with hydrogen, which burned in the cylinder and finally pushed the piston to reciprocate. This invention was granted a French patent on1807 65438+1October 30th, which is the first patent on automobile products. However, due to the limited technical level at that time, the production and use of hydrogen was far more complicated than the use of steam and gasoline, so the hydrogen internal combustion engine was "submerged" by steam engines, diesel engines and gasoline engines. During World War II, hydrogen was used as a liquid propellant for the A-2 rocket engine. 1960 used liquid hydrogen as space power fuel for the first time, and 1970 used the take-off rocket of Apollo spacecraft launched by the United States to use liquid hydrogen as fuel. Now hydrogen has become a common fuel in the rocket field. For the modern space shuttle, it is more important to reduce the fuel weight and increase the payload. The energy density of hydrogen is very high, which is three times that of ordinary gasoline, which means that the weight of the space shuttle can be reduced by two thirds by using hydrogen as fuel, which is undoubtedly very beneficial to the space shuttle. In addition, hydrogen can also be used in spacecraft. Now scientists are studying a "solid hydrogen" spacecraft. Solid hydrogen is not only used as the structural material of spacecraft, but also as the power fuel of spacecraft. During the flight, all non-important parts of the spacecraft can be converted into energy and "consumed", so that the spacecraft can fly in the universe for a longer time. At the end of 1980s, a variety of fuel cell vehicles were publicly displayed, and at the end of 1990s, the feasibility of replacing storage batteries with small fuel cells was confirmed. 2 1 century, faced with the crisis of environmental pollution, hydrogen fuel cells developed rapidly, and more shaped hydrogen fuel cell vehicles began to enter the market. As a new energy source that obstinately confronts the current difficulties of mankind, the development status of hydrogen energy has become the object of vigorous research in various countries. According to the survey of the New Energy Development Center of the US Department of Energy (DOE), in the past five years, the investment in hydrogen energy development in industrialized countries all over the world has increased by 20.5% every year. The United States has always attached importance to hydrogen energy. In 2003, Bush invested $654.38+0.7 billion to start the hydrogen fuel development plan, and put forward key development projects such as hydrogen energy industrialized production technology, hydrogen energy storage technology and hydrogen energy application. In February, 2004, the U.S. Department of Energy announced the action plan of research, development and demonstration of hydrogen energy technology, and elaborated the steps of developing hydrogen economy and the timetable of transition to hydrogen economy in detail. The introduction of the plan is another important measure to promote the development of hydrogen economy in the United States, which marks that the development of hydrogen economy in the United States has entered the stage of system implementation from the stage of policy evaluation and formulation. In May 2004, the first hydrogen station in the United States was established, and the third-generation home energy station, California's fixed hydrogen generation device, began to be tried out. In July 2005, Daimler Chrysler, one of the earliest companies producing hydrogen fuel cells in the world, successfully developed the "fifth generation new battery car" across the United States, setting a new record for fuel cell vehicles. The car is powered by hydrogen, with a total mileage of 5245km and a top speed of 65438+. For China, energy construction strategy is the key strategy of national economic development. Among the proven recoverable reserves of fossil energy in China, the coal amount is114.5 billion t, the oil amount is 3.8 billion t, and the natural gas reserves are 1.37 trillion m3, accounting for1.6% and 2.6% respectively. China has a large population and insufficient per capita resources. The per capita proven recoverable reserves of coal are only 1/2 of the world average, while that of oil is only about110, and the per capita energy possession is obviously backward. At the same time, in recent years, the proportion of transportation energy in China is increasing. At the same time, automobile exhaust pollution has become the most important factor of air pollution, especially urban air pollution. Therefore, finding new clean energy is of great significance to the sustainable development of China. During the Ninth Five-Year Plan and the Tenth Five-Year Plan, the Ministry of Science and Technology included the research and development of fuel cell vehicles and related technologies in the national science and technology plan. In June 2002, the Chinese Academy of Sciences launched a major project of the strategic action plan for scientific and technological innovation-high-power proton exchange membrane fuel cell engine and hydrogen energy technology, which was presided over by Dalian Institute of Chemical Physics of the Chinese Academy of Sciences. Based on the National High-tech Development Plan of the Ministry of Science and Technology ("863"), 75KW and 150KW fuel cell engines with independent intellectual property rights and complete sets of hydrogen energy technologies will be developed to help China enter the hydrogen energy era as soon as possible. At present, China has successfully developed cars and buses other than fuel cells, and the cumulative experimental operation has exceeded 2000km, which indicates that China has the ability to develop hydrogen-powered fuel cell engines. When the 2008 Olympic Games and the 20 10 World Expo were held, fuel cell vehicles were already running on the streets in small batches. Preparation method of hydrogen energy 1. Hydrogen production from fossil fuels In the traditional hydrogen production industry, hydrogen production from fossil fuels is the most widely used method, with mature technologies and industrial devices. The main methods are partial oxidation reforming of heavy oil, steam reforming of natural gas and coal gasification. The chemical reaction of hydrogen production from steam and natural gas is: CH 4 +2H 2 O=CO 2 +4H 2. The basic reaction process of hydrogen production from steam and coal is: C+2H 2 O=CO 2 +2H 2. Although at present more than 90% of hydrogen production is based on natural gas and coal. But the reserves of natural gas and coal are limited, and the process of hydrogen production will pollute the environment. According to the requirements of Scientific Outlook on Development, this method is obviously not the best choice for hydrogen production technology in the future. 2. Hydrogen production by electrolysis of water has a long industrial history. This method is based on the following reversible reaction between hydrogen and oxygen: 2H 2 O=2H 2 +O 2. At present, the commonly used electrolyzers generally adopt filter-pressing bipolar structure or box-type single-stage structure. The pressure of each pair of electrolyzers is between1.8 and 2.0v, and the energy consumption for producing 1m3H2 is between 4.0 and 4.5kwh.. The advantages of box structure are simple equipment, convenient maintenance and less investment, but the disadvantages are large floor space and low space-time yield. The structure of filter press is relatively complex, with the advantages of compactness, small floor space and high space-time yield, and the disadvantages of difficult maintenance and large investment. With the development of science and technology, solid polymer electrolyte (SPE) electrolyzers appeared. The material of solid phase extraction tank is easily available and suitable for large-scale production. In addition, the efficiency of separating H _ 2 and O _ 2 with the same number of anodes and cathodes is higher than that of conventional alkaline electrolyzers. In addition, the liquid flow rate of SPE electrolyzer is110 of conventional alkaline electrolyzer, and its service life is about 300 days. The disadvantage is that the energy consumption of electrolyzed water is still high. At present, China's water electrolysis industry is still at the level of filter-pressing bipolar electrolyzer or single-stage box electrolyzer, which is still far from the foreign industry and research level. 3. Hydrogen production by catalytic pyrolysis of methane The traditional process of hydrogen production by methane pyrolysis is accompanied by a large amount of carbon dioxide emission. However, in recent years, hydrogen production by thermal decomposition of methane has become a research hotspot. Methane decomposition 1mol hydrogen requires 37.8KJ of energy and emits 0.05 mol of CO 2. The main advantage of this method is that while producing high-purity hydrogen, it can produce more economic value and more easily occurring solid carbon, so as not to emit carbon dioxide into the atmosphere and reduce the greenhouse effect. Because it basically does not produce CO 2, it is considered as a transitional process between fossil fuels and renewable energy. But the production cost is not low. If the by-product carbon has a broad market prospect, this method will become a promising hydrogen production method. 4. Bio-hydrogen production technology can save non-renewable energy and reduce the pollution of Polygonatum sibiricum, which may become one of the main development directions of energy preparation technology in the future. Bio-hydrogen production is the biochemical reaction between microbial enzymes and hydrogen-containing substances (including plant starch, cellulose, sugar and other organic substances and water) at normal temperature and pressure to produce hydrogen. So far, the reported hydrogen-producing organisms can be divided into two categories: photosynthetic organisms (anaerobic photosynthetic bacteria, cyanobacteria and green algae) and non-photosynthetic organisms (strict anaerobic bacteria, facultative anaerobic bacteria and aerobic bacteria). Photosynthetic organisms cyanobacteria and green algae can convert solar energy into hydrogen energy by using ingenious photosynthetic structure in vivo, so their hydrogen production research is far deeper than that of non-photosynthetic organisms. Both of them can photolyse water to produce hydrogen, which is an ideal way to produce hydrogen. However, cyanobacteria and green algae release hydrogen at the same time, and besides the low efficiency of hydrogen production, how to solve the inactivation of hydrogenase exposed to oxygen is the key problem to be solved in this technology. Compared with cyanobacteria and green algae, anaerobic photosynthetic bacteria do not produce oxygen during anaerobic photosynthetic hydrogen release, so the process is simple. At present, in view of the complexity and precision of photosynthetic hydrogen release process, the research content is still mainly focused on the screening or breeding of high-activity hydrogen-producing strains, breeding and controlling environmental conditions to improve hydrogen production, and its research level and scale are basically at the laboratory level. Non-photosynthetic organisms can degrade macromolecular organic compounds to produce hydrogen, which makes them show advantages over photosynthetic organisms in the study of hydrogen production from renewable energy substances (cellulose and its degradation products and starch, etc.). ). The research on this kind of microorganism as hydrogen source began in 1960s, and by the end of 1990s, China scientist Ren Nanqi and others developed the "Bio-hydrogen Production Technology by Fermentation of Organic Wastewater" with anaerobic activated sludge and organic wastewater as raw materials. This technology breaks through the limitation that pure bacteria and immobilized technology must be used in biological hydrogen production technology, and creates a new way to produce hydrogen by using non-immobilized bacteria. The pilot test results show that the maximum continuous hydrogen production capacity of the bio-hydrogen production reactor reaches 5.7m3/(m3. Characteristics (1) Hydrogen is the most common element in nature. It is estimated that it accounts for 75% of the mass of the universe. Except hydrogen in the air, it is mainly stored in water in the form of compounds, and water is the most widely distributed substance on the earth. (2) Among all gases, hydrogen has the best thermal conductivity, which is 10 times higher than that of most gases, so hydrogen is an excellent heat transfer carrier in the energy industry. Except for nuclear fuel, the calorific value of hydrogen is the highest among all fossil fuels, chemical fuels and biofuels, reaching 142.35 LKJ/ kg. The heat per kilogram of hydrogen after combustion is about 3 times that of gasoline, 3.9 times that of alcohol and 4.5 times that of coke. (5) Of all the elements, hydrogen is the lightest. In the standard state, its density is 0.0899 g/L; Hydrogen can appear in the form of gaseous, liquid or solid metal hydride, which can meet the different requirements of storage, transportation and various application environments. (6) Hydrogen itself is nontoxic, and it is cleanest when burning compared with other fuels. Except water and a small amount of hydrogen nitride, it will not produce pollutants harmful to the environment, such as carbon monoxide, carbon dioxide, hydrocarbons, lead compounds and dust particles, and a small amount of hydrogen nitride will not pollute the environment after proper treatment. Moreover, the water produced by combustion can continue to produce hydrogen, and repeated use of hydrogen can be safely used. A lot of practice shows that hydrogen has a record of safe use. Between 1967 and 1977, there were 145 hydrogen accidents in the United States, all of which occurred in oil refining, chlor-alkali industry or nuclear power plants, and did not really involve energy utilization. The experience of using hydrogen at home and abroad shows that the common accidents of hydrogen can be summarized as follows: undiscovered leakage; Valve failure or leakage; Safety valve failure; Failure of evacuation system; The pipeline or container is broken; Material damage; Poor replacement, impurities such as air or oxygen remain in the system; Hydrogen emission rate is too high; The pipeline joint or bellows is damaged; Collision or rollover accident occurred during hydrogen transportation. These accidents need to be supplemented by two conditions to cause a fire. One is a fire source, and the other is a mixture of hydrogen and air or oxygen. At that time and place, it should be at the limit of fire or violent vibration. Without these two conditions, it is impossible to cause an accident. In fact, most accidents can be avoided through strict management and careful implementation of operating procedures. There are three main ways to use hydrogen energy: ① direct combustion; (2) it is converted into electric energy by burning the battery; ③ Nuclear fusion. Among them, the safest and most effective method is to convert hydrogen energy into electric energy through fuel cells. At present, the development of hydrogen energy is triggering a profound energy revolution, which may become the main energy source in 2 1 century. Developed countries such as the United States, Europe and Japan have formulated long-term hydrogen energy development strategies from the perspective of national sustainable development and security strategy. 1, hydrogen internal combustion engine The basic principle of hydrogen internal combustion engine is the same as that of gasoline or diesel internal combustion engine. The hydrogen internal combustion engine is a slightly improved version of the traditional gasoline internal combustion engine. Hydrogen internal combustion directly burns hydrogen, without using other fuels, and does not produce water vapor discharge. Hydrogen internal combustion engine can do work completely without any expensive special environment and catalyst, so there will be no problem of high cost. At present, many successful hydrogen internal combustion engines are hybrid, that is, liquid hydrogen and gasoline can be used as fuels. In this way, the hydrogen internal combustion engine has become a good transitional product. For example, if you can't reach your destination after refueling once, but you can find a hydrogen refueling station, use hydrogen as fuel; Or use liquid hydrogen first, and then find an ordinary gas station to add gasoline. In this way, people will not be afraid to use hydrogen-powered cars when hydrogen refueling stations are not popular. Hydrogen internal combustion engine is easy to realize lean combustion because of its small ignition energy, and can obtain better fuel economy in a wide range of working conditions. 2. The application of hydrogen energy in fuel cells is mainly realized by fuel cells. The basic principle of hydrogen fuel cell power generation is the reverse reaction of electrolytic water. Hydrogen and oxygen are supplied to the cathode and anode respectively. Hydrogen diffuses outward through the cathode and reacts with the electrolyte, releasing electrons and reaching the anode through the external load. The main differences between hydrogen fuel cells and ordinary batteries are: dry cells and storage batteries are energy storage devices, which store electric energy and release it when necessary; Strictly speaking, hydrogen fuel cell is a kind of power generation device, and like power plants, it is an electrochemical power generation device that directly converts chemical energy into electrical energy. Using hydrogen fuel cell to generate electricity, the chemical energy of combustion is directly converted into electric energy, and the energy conversion rate can reach 60% ~ 80% without combustion. The pollution and noise are small, and the device can be large or small, which is very flexible. In essence, the working mode of hydrogen combustion battery is different from that of internal combustion engine. Hydrogen-burning batteries generate electric energy through chemical reactions to propel automobiles, while internal combustion engines propel automobiles by burning heat energy. Because the working process of the fuel cell vehicle does not involve combustion, there is no mechanical loss and corrosion, and the electric energy generated by the hydrogen combustion battery can be directly used to propel the four wheels of the vehicle, eliminating the mechanical transmission device. Now, researchers in developed countries have been strongly aware of the inevitable trend that hydrogen fuel cells will end the era of internal combustion engines. Automakers that have successfully developed hydrogen fuel cells include GM, Ford, Toyota, Mercedes-Benz, BMW and other international companies. 3. Nuclear fusion Nuclear fusion, that is, when hydrogen nuclei (deuterium and tritium) combine to form a heavier nucleus (helium), huge energy is released. Thermonuclear reaction, or nuclear upheaval reaction, is a promising new energy source. Hydrogen nuclei involved in nuclear reactions, such as hydrogen, deuterium, fluorine, lithium, etc. Obtaining necessary kinetic energy from thermal motion and causing fusion reaction. Thermonuclear reaction is the basis of hydrogen bomb explosion, which can generate a lot of heat energy in an instant, but it can't be used yet. If the thermonuclear reaction can be controlled in a certain restricted area according to human intention, the controlled thermonuclear reaction can be realized. This is an important subject of experimental research at present. Controlled thermonuclear reaction is the basis of fusion reactor. Once the fusion reactor is successful, it may provide mankind with the cleanest and inexhaustible energy. At present, the controlled nuclear fusion reactor with greater feasibility is the Tokamak device. Tokamak is a kind of annular container which uses magnetic confinement to realize controlled nuclear fusion. His name Tokamak comes from Ring, kamera, Magnetism and kotushka. It was originally invented by Achimovich of Kurchatov Institute in Moscow, Soviet Union in 1950s. The center of the Tokamak is an annular vacuum chamber surrounded by coils. When the power supply is turned on, a huge spiral magnetic field will be generated inside the tokamak, which will heat the plasma to a very high temperature, thus achieving the purpose of nuclear fusion. China also includes two nuclear fusion experimental devices. Looking forward to the problems of energy, resources and environment, hydrogen energy is urgently needed to solve this crisis, but the preparation of hydrogen energy is not mature at present, and most of the research on hydrogen storage materials is still in the stage of laboratory exploration. The preparation of hydrogen energy should be based on biological hydrogen production, and other hydrogen production methods are unsustainable and do not meet the requirements of scientific development. Microbial hydrogen production in biological hydrogen production needs the organic combination of genetic engineering and chemical engineering, and make full use of the existing technology to develop hydrogen-producing organisms that meet the requirements as soon as possible. Hydrogen production from biomass requires continuous improvement and vigorous promotion of technology, which is a difficult process. Hydrogen storage mainly focuses on the discovery of new materials, without considering the large-scale or industrial preparation of materials, and the hydrogen storage mechanism of different hydrogen storage materials needs further study. In addition, because each hydrogen storage material has its advantages and disadvantages, and most hydrogen storage materials have addition characteristics, the performance of a single hydrogen storage material is more recognized by people. Therefore, it is considered that the development of composite hydrogen storage materials that combine the advantages of various single hydrogen storage materials is a development direction of hydrogen storage materials in the future.