Hydrogen and oxygen fuel cell conversion efficiency, energy conversion efficiency of fuel cells?

No electricity is available for combustion.

However, the conversion rate of conversion into electrical energy cannot reach 100%, because some chemical energy is converted into heat energy or something (fuel cells also generate heat when used continuously, which means that some energy is not converted into electrical energy).

Fuel cell is a power generation device that directly converts the chemical energy of fuel into electrical energy, and it is a new power generation technology after thermal power generation, hydropower generation, solar power generation and nuclear power generation.

The fuel cell is mainly composed of four parts: anode, cathode, electrolyte and external circuit. When the fuel gas enters the anode, electrons and ions are released under the action of the catalyst, and the electrons are conducted to the cathode through the external circuit to generate an electric current. Under the action of an electric field, ions migrate to the cathode through the electrolyte and undergo oxidation reaction with electrons and oxygen to form water.

In the past, the active material of the battery was stored inside the battery, so the battery capacity was limited. The positive and negative electrodes of the fuel cell do not contain active substances and do not store electrical energy themselves, but are only catalytic conversion components, which are energy conversion machines that truly convert chemical energy into electrical energy, and to put it bluntly, it is a generator. As long as the fuel gas is continuously fed, the fuel cell can continuously generate electricity.

Hydrogen fuel cells are energy-efficient and efficient, with energy conversion up to 80%; Energy saving and environmental protection, no pollution and no noise, hydrogen fuel is extensive.

40 to 60, which will be a bit higher than an internal combustion engine.

Hydrogen-oxygen fuel cells (neutral medium).

Positive electrode: O2 + 2H2O + 4E- 4OH - Negative electrode: 2H2 - 4E- 4H+

Total Acacia reaction formula: 2H2 + O2 ==2H2O hydrogen-oxygen fuel cell (acidic medium).

Positive electrode: O2 + 4H+ +4E- 2H2O negative shade: 2H2 - 4E- 4H+

Total reaction formula: 2H2 + O2 ==2H2O

Hydrogen and oxygen are burned to make a noise battery (alkaline medium).

Positive electrode: O2 + 2H2O + 4E- 4OH - Negative electrode: 2H2 - 4E- +4OH- 4H2O Total reaction formula: 2H2 + O2 ==2H2O

Chemistry.

1. If the electrolyte is an acid solution

1. The negative electrode reaction formula is: 2H2-4E-==4H+.

2. The positive electrode reaction formula is: O2 + 4H+ +4E ==2H2O.

Second, if the electrolyte solution.

It is a alkali solution: 1, and the negative electrode reaction formula is: 2H2 + 4OH -4E ==4H20.

2. The positive electrode reaction formula is: O2 + 2H2O + 4E ==4OH.

Hydrogen-oxygen fuel cell property analysis:

1. The active substances (fuel and oxidizer) of the fuel cell are continuously input at the same time as the reaction, so this type of battery is actually just an energy conversion device.

2. This type of battery has the advantages of high conversion efficiency, large capacity, high specific energy, wide power range, and no need to charge, but due to the high cost, the system is more complex, and it is limited to some special purposes, such as spacecraft, submarines, military, TV transfer stations, lighthouses and buoys.

The above content reference: Encyclopedia - Hydrogen and oxygen fuel cells.

The battery energy conversion efficiency of fuel cell electric vehicles can be considered from two aspects:

1.Efficiency of the fuel cell system: The fuel cell system converts hydrogen and oxygen into electricity in an electrochemical reaction, which releases water at the same time as the cherry tree ridge. The efficiency of a fuel cell system can typically reach around 50% to 60%.

2.Drive efficiency of electric vehicles: Converting the electrical energy output from the fuel cell system into mechanical energy to drive the vehicle requires components such as motors and transmissions.

The efficiency of the motor is usually between 80% and 90%, and the efficiency of the transmission is also above 90%. Therefore, the conversion efficiency of battery energy and capacity of fuel cell electric vehicles can usually reach about 40% to 50%.

Hydrogen in oxy-fuel cells refers to hydrogen, and the preparation of hydrogen is of course varied.

1. Hydrogen production by electrolysis of water.

A series electrolyzer (similar to a filter press) with iron as the cathode surface and nickel as the anode surface is mostly used to electrolyze the aqueous solution of caustic potassium or caustic soda. The anode produces oxygen, and the cathode produces hydrogen. This method is costly, but the product purity is large, and hydrogen of the above purity can be directly produced.

This pure hydrogen is often used for: reducing agent, shielding gas and heat treatment of permalloy used in electronics, instruments and meters industry, reducing agent used in the production of tungsten, molybdenum and cemented carbide in powder metallurgy industry, preparation of semiconductor raw materials such as polysilicon and germanium, hydrogenation of grease and grease, cooling gas in dihydrogen internal coolant generators, etc. For example, the Beijing Electron Tube Factory and the Gas Plant of the Academy of Sciences use water electrolysis to produce hydrogen.

2. Water gas method to produce hydrogen.

Anthracite or coke is used as raw material to react with water vapor at high temperature to obtain water gas (C+H2O+H2-heat).After purification, it is then converted into CO2 (CO+H2O, CO2+H2) through the catalyst together with water vapor to obtain a gas with a hydrogen content of more than 80%, and then pressed into water to dissolve CO2, and then remove the residual CO in the ammonic acidic acid (or cuprous aminoacetate) solution to obtain purer hydrogen, the hydrogen production cost of this method is lower, the output is large, and the equipment is more, and this method is used more in the synthetic ammonia plant. Some also synthesize methanol from CO and H2, and in a few places, 80% hydrogen is used as a less pure gas for artificial liquid fuel.

For example, the Beijing Chemical Experimental Plant and many small nitrogen fertilizer factories in many places use this method.

3. Hydrogen production from syngas and natural gas from petroleum hot cracking.

The hydrogen production by-product of petroleum thermal cracking is very large, and it is often used for gasoline hydrogenation, hydrogen required by petrochemical and fertilizer plants, this hydrogen production method is used in many countries in the world, and in China's petrochemical bases such as in Qing Fertilizer Plant, Bohai Oilfield Petrochemical Base, etc., this square limb is used to produce hydrogen.

It is also used in some places (such as the Bay, Way and Batan Rougo hydrogen refueling plants in the United States, etc.).

4. Coke oven gas refrigeration hydrogen production.

The preliminarily purified coke oven gas is frozen and pressurized to liquefy other gases and leave hydrogen. This method is used in a few places (e.g. the Ke Mepobo factory in the former Soviet Union).

5. Hydrogen by-product of electrolysis of salt water.

In the chlor-alkali industry, there is a large amount of pure hydrogen by-products, which is surplus in addition to the synthesis of hydrochloric acid, and can also be purified to produce ordinary hydrogen or pure hydrogen. For example, the hydrogen used in the second chemical plant is a by-product of electrolysis of brine.

6. By-products of brewing industry.

When using corn to ferment acetone and butanol, there is more than 1 3 hydrogen in the exhaust gas of the fermenter, and after many times of purification, it can produce general hydrogen (more than 97%), and the general hydrogen can be further removed by cooling the silica gel tube below -100 with liquid nitrogen to further remove impurities (such as a small amount of N2) to produce pure hydrogen (above), such as Beijing distillery produces this by-product hydrogen, which is used to burn quartz products and use it for foreign units.

7. Hydrogen production by reaction of iron and water vapor.

However, the quality is poor, and the older methods of this system have been largely phased out.

Summary. The history of the development of hydrogen and oxygen fuel cells is that in 1839, the British physicist William Grove made the first fuel cell. Fuel cells were first used in NASA's 1960s space missions to power probes, satellites and capsules.

Since then, fuel cells have been widely used in industry, housing, transportation, etc., as a basic or backup power supply device.

The development of hydrogen and oxygen fuel cells is as follows: In 1839, British physicist William Grove made the first fuel cell. Fuel cells were first used in NASA's 1960s space missions to power probes, satellites and capsules. Since then, the stove battery has been widely used in industry, housing, transportation, etc., as a basic or backup power supply device.

During operation, fuel (hydrogen) is supplied to the negative electrode and an oxidant (air in the Hui Grip section is supplied to the positive electrode, and oxygen is the component that works).Hydrogen decomposes at the negative electrode into the positive ion h+ and the electron e-Hydrogen ions enter the electrolyte, while electrons move along the external Pitcher's circuit towards the positive electrode.

The load of electricity is connected to the external circuit. At the positive electrode, oxygen in the air and hydrogen ions in the electrolyte absorb electrons that reach the anterior electrode to form water. This is precisely the inverse process of the electrolysis reaction of water.

In 2000, with the increase in demand for renewable energy and clean energy, hydrogen and oxygen fuel cell technology has been further researched and developed. Many automakers and energy companies have begun to invest and cooperate to promote the development of hydrogen and oxygen fuel cell vehicles. Since the 2010s, hydrogen and oxygen fuel cell technology has been widely used in transportation, energy storage and industry, especially in the fields of heavy-duty trucks, buses and hydrogen stations.

You can find out about the history of the development of hydrogen and oxygen fuel cells.

History and development of fuel cells in libraries.