The problem is that the energy conversion is not spontaneous and requires the loss of external energy. The electrolysis of water produces hydrogen and oxygen. Where does electricity come from? Judging from the current technical level, it is not worth electrolyzing water to obtain hydrogen energy. Water supply efficiency for producing hydrogen is typically 75-85%. This and the difficulty of hydrogen storage materials are the reasons why hydrogen energy is not currently used in large quantities.
In addition, most of the energy generated by combustion will be dissipated as heat. Currently, the best internal combustion engines can only achieve less than 55% efficiency, usually only 30-40%. The efficiency of water electrolysis to obtain hydrogen energy for combustion will not reach 50%. However, the efficiency of productionhydrogen-based electricity generation can reach 50 to 70%. So, are you going to use the hydrogen you worked so hard to obtain through electrolysis to produce electricity?
However, hydrogen does indeed constitute an attractive new energy source.
Haha, don’t you understand? Please note that I mentioned hydrogen storage to illustrate that hydrogen is not widely used. Your response is not an attempt to avoid the important but to avoid the weak. . . . Please express your opinion on the essence of the problem "energy use". The above figures are purely ideal and theoretical. In fact, it would be a miracle if your solution could achieve 10% overall electrical energy efficiency. However, if electrical power is used to directly drive a car, the efficiency is likely to be higher. 70% to 80%.
Please also pay attention to the question of itssee where the electrical energy comes from. Electrical energy is not a primary energy source. Do you use nuclear power, solar power, hydropower, tidal or coal? Which one does not have such defects?
Principle of hydrogen fuel cell
Basically, hydrogen is not the main form of energy in modern society, and there is no does not have many opportunities for its use when the cost is high. high, it is naturally When it comes to hydropower, few people use it. On the one hand, the electricity transmission method is relatively mature and inexpensive. On the other hand, hydroelectric plants have more efficient energy storage measures during peak periods. : When power consumption is low, just use the remaining electricity to pump water. But this is not the case. Electrolysis of water to produce hydrogen has no application: eAs a substance with the same high energy density as oil, it can be used. as a source of clean energy to replace oil in places where electricity is not suitable, such as rockets, airplanes, ships, etc., in addition, as an intermediate substance for energy storage, use wind power and photovoltaic power to electrolyze water to produce hydrogen; , and then produce electricity through gas turbines, can effectively solve the problem of integrating a new energy network. The problem with liquid hydrogen is that there is currently no particularly efficient and safe storage method. Large quantities of storage still rely on low temperature and high pressure. Not only is it expensive and dangerous, but it is acceptable for use in rocket engines, but not for civilian and commercial use. Inasmuch assolution, the storage of metal hydrides in the solid state has sweet dreams and a cruel reality. It still belongs to the category of rare metals, and it is far from possible to have safe and efficient storage in the future, combined with wind energy. photovoltaic and electrical energy provided by nuclear energy have declined considerably, and it is quite possible that hydrogen energy will replace oil energy in some regions.
The principle of a hydrogen fuel cell is to use hydrogen and oxygen to undergo an oxidation-reduction reaction on the electrode to produce electrical energy.
Hydrogen fuel cells are power generation devices that use hydrogen as a fuel and directly convert the chemical energy contained in the fuel into electrical energy through electrochemical reactions. The principle of operationThe basic principle of a hydrogen fuel cell is the reverse reaction of electrolytic water, supplying hydrogen and oxygen to the anode and cathode, respectively. After the hydrogen diffuses outward through the anode and reacts with the electrolyte, the electrons are released and reach the cathode via a channel. external load. Hydrogen is broken down into electrons and hydrogen ions (protons) by a catalyst (platinum) located in the positive electrode of the fuel cell.
Protons pass through the proton exchange membrane to the negative electrode and react with oxygen to become water and heat. The corresponding electrons flow from the positive electrode to the negative electrode through the external circuit to generate electrical energy. Hydrogen fuel cell electrodes are typically made of precious metals such as platinum, palladium and rhodium. A catalystprecious metal on the anode promotes the hydrogen oxidation reaction, thus producing electrons. A precious metal catalyst on the cathode promotes the oxygen reduction reaction, which accepts electrons and forms water.
Application fields of hydrogen fuel cells
In the 1960s, hydrogen fuel cells were successfully used in the field aerospace. The “Apollo” spacecraft that traveled between space and earth was equipped with this small size and large capacity device. After the early 1970s, as people continued to master various advanced hydrogen production technologies, hydrogen fuel cells were soon used in power generation and automobiles.
Large-scale power plants, whether hydroelectric, thermal or nuclear, send the electricity they producetransmitted to the network, which then delivers it to users. However, due to the different loads of each electricity user, the electricity grid sometimes experiences peaks and sometimes troughs, which can lead to power outages or voltage instability.
In addition, about 70% of the combustion energy of traditional thermal power plants is consumed in huge equipment such as boilers and turbogenerators. When burning, a large amount of energy is consumed and a large amount of harmful substances. substances are emitted. Using hydrogen fuel cells to generate electricity directly converts the chemical energy of the fuel into electrical energy without burning. The energy conversion rate can reach 60%-80%. It also has less pollution and low noise. small and very flexible.