Preparation method of hydrogen, storage method and working principle of hydrogen fuel cell

Hydrogen is not only an important industrial raw material and reducing agent, but also a necessary fuel for fuel cells. With the promotion and popularization of fuel cells, fuel cell vehicles enter mature markets, and hydrogen consumption will also increase at an alarming rate. At present, there are several main methods of industrial hydrogen production:

One is the use of fossil fuels to produce hydrogen; the second is the extraction of hydrogen from chemical by-products; The third is to use methanol methane from living organisms to produce hydrogen, and the fourth is to use natural energy such as solar energy and wind energy for water electrolysis. Shelter code.

1. Storage of hydrogen gas mass information: put the hydrogen in the gas storage tank after pressurization.

2. Laboratory method: react with strong acid and active metal, such as Zn+2HCl=ZnCl2+H2; It reacts with water with alkali metal collapse, such as 2Na+2H2O=2NaOH+H2. Frankly not.

3. Industrial method: the use of electrolysis of saturated brine to produce hydrogen, such as 2NaCl + 2H2O = energized = 2NaOH + Cl2 + H2, which is also a method for industrial chlorine production.

Summary. A hydrogen fuel cell is a power generation device that converts the chemical energy of hydrogen and oxygen directly into electrical energy. The basic principle is the reverse reaction of electrolysis of water, where hydrogen and oxygen are supplied to the anode and cathode respectively, and after the hydrogen diffuses outward through the anode and reacts with the electrolyte, the electrons are released to the cathode through the external load.

Hydrogen fuel cells are power generation devices that directly convert the chemical energy of hydrogen and oxygen into electrical energy. The basic principle is the reverse reaction of electrolysis of water, in which hydrogen and oxygen are supplied to the anode and the cathode respectively, and the hydrogen diffuses outward through the anode, and after the reaction with the electrolyte, the electrons are released to the cathode through the external load.

A fuel cell is an energy conversion device that converts the electrochemical energy of a fuel into electrical energy. It is also an electrochemical power generation device similar to a battery, so it is called a fuel cell. The corresponding fuel cell that uses hydrogen as fuel is a hydrogen fuel cell.

It can be understood as the reverse reaction of water electrolysis into hydrogen and oxygen. As a result, the reaction process is both clean and efficient. Because it is not limited by the thermal efficiency of about 42% of the Carnot cycle used in conventional engines.

The efficiency of hydrogen fuel cells can easily reach more than 60%. Hydrogen fuel cells do not generate kinetic energy through the violent reaction of hydrogen and oxygen combustion like rockets, but release the Gibbs free energy in hydrogen through a catalytic device. For example, graphite and diamond are both carbon situations.

But forming a diamond requires high temperatures and pressures. Thus this morphological transformation represents a different Gibbs free energy. Hydrogen fuel cells work by splitting hydrogen into electrons and hydrogen ions (protons) through a catalyst (platinum) in the cathode of the fuel battery.

Protons reach the negative electrode through proton exchange membranes, 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.

Hope mine is helpful to you.

There are many ways to store hydrogen, but there are no efficient ways to store it.

The main methods are: liquefaction of hydrogen storage (which is too expensive and requires a lot of energy to maintain its liquefaction); Compressed hydrogen storage (low gravimetric and bulk density); Metal hydride stores hydrogen (higher volume storage density, but low weight density), and carbon nanotubes, which are currently being studied.

Adsorption of hydrogen storage (has been demonstrated at room temperature and less than 1 bar (about one atmosphere.)

Single-walled carbon tubes can adsorb 5%-10%, and multi-walled carbon nanotubes can store up to 14% of hydrogen, but these reports have been questioned because there is no world-recognized detection standard for detecting hydrogen storage in carbon nanotubes

At present, according to theoretical calculations and repeated verifications, it is generally believed that the reversible hydrogen storage and release capacity is about 5% (mass density percentage), but even if it is only 5%, it is the best hydrogen storage material so far!

This is the teacher's note from my nanomaterials class, and I was so tired.

Hydrogen storage: Put the hydrogen under pressure and put it in the hands of the gas tank.

There are laboratory and industrial methods for hydrogen production.

Laboratory method: 1. React with strong acid and active metal, such as Zn+2HCl=ZnCl2+H2

2. Reaction with alkali metal and water, such as 2Na + 2H2O = 2NaOH + H2 Industrial method: the use of electrolysis of saturated brine to produce hydrogen, such as 2NaCl + 2H2O = energized = 2NaOH + Cl2 + H2, which is also a method for making chlorine in industry.

A fuel cell is a kind of battery that directly converts chemical energy into electrical energy by electrochemical reaction without combustion. Whether it is a low-temperature fuel cell, a medium-temperature fuel cell or a high-temperature fuel cell, the main fuel used is hydrogen, although there are many hydrogen (such as natural gas, media, oil, etc.), and the technology obtained is also quite mature, but its storage and transportation have always been the main technical bottlenecks and problems for the application of hydrogen energy.

At present, there are four main storage methods of hydrogen: room temperature and high pressure, room temperature and high pressure carbon adsorption, low temperature liquefaction and hydrogen storage alloy. Depending on the material, the system can store 1 7% of hydrogen (if the porous carbon material is built-in, the hydrogen storage capacity can be slightly increased), but due to the high-pressure compression of hydrogen, it needs to consume 20% of the energy contained in the compressed hydrogen; As for the storage of hydrogen at low temperature, although the hydrogen storage capacity of the system can reach about 16% at atmospheric pressure and low temperature, the liquefaction of hydrogen requires about 40% of the energy contained in the liquefied hydrogen, and there are shortcomings such as volatile consumption of hydrogen, which are the main fatal injuries of this hydrogen storage method. As for the hydrogen storage mode of hydrogen storage alloy, its hydrogen storage density can reach 1,500 cm3h2 cm3, which is much higher than the 200 cm3 cm3 at room temperature and high pressure (200 atmospheres) and 784 cm3 at low temperature (-273oc) liquefaction mode, and there is no danger and loss of long-term storage.

In the past 20 years, it has been influenced by international manufacturers, such as Ergenics Inc. in the United States(NJ, USA), Germany's GFE (Gesellschaft für Elektrometallurgie), the UK's Shell and Canada's Hydro Quebe have formed a strategic alliance, and Japan's Japan Heavy Chemicals & Chemicals Co,ltd.

JMC) and Nippon Steel are conducting R&D through strategic alliances.

Industrial methods for producing hydrogen:

1. Water gas method (main components CO and H2), carbon and water are reacted to generate carbon monoxide and hydrogen under high temperature conditions, and the reaction equation is as follows

2. The method of electrolysis of water to produce hydrogen, electrolysis of water under the condition of electricity, the generation of oxygen and hydrogen, the reaction equation is as follows:

3. Electrolysis of saturated brine, sodium chloride and water under the condition of electricity to generate sodium hydroxide, hydrogen and oxygen, the reaction equation is as follows:

Electrolyzed water generally refers to the product produced by the electrolysis of water containing salts (such as sodium chloride). The electrolyzed water itself is neutral and other ions can be added, or it can be separated by a semi-permeable membrane to form water with both properties.

One of them is alkaline ionized water and the other is acidic ionized water. Electrolyzed water with sodium chloride as the electrolyte contained in water will contain sodium hydroxide, hypochlorous acid and sodium hypochlorite after electrolysis (if pure water is electrolyzed, only hydroxide ions, hydrogen gas, oxygen and hydrogen ions will be produced).