During the electrolysis process takes place at the anode. Practical application of electrolysis

Processes during electrolysis

Electrolysis has become widespread in the metallurgy of non-ferrous metals and in a number of chemical industries. Metals such as aluminum, zinc, magnesium are obtained mainly by electrolysis. In addition, electrolysis is used for the refining (purification) of copper, nickel, lead, as well as for the production of hydrogen, oxygen, chlorine and a number of other chemicals.

The essence of electrolysis consists in the separation of particles of a substance from the electrolyte when a direct current flows through an electrolytic bath and their deposition on electrodes immersed in the bath (electroextraction) or in the transfer of substances from one electrode through the electrolyte to another (electrolytic refining). In both cases, the goal of the processes is to obtain the purest possible substances that are not contaminated with impurities.

Unlike metals in electrolytes (solutions of salts, acids and bases in water and in some other solvents, as well as in molten compounds), ionic conductivity is observed.

Electrolytes are second class conductors. In these solutions and melts, electrolytic dissociation takes place - decay into positively and negatively charged ions.

If electrodes connected to an electric energy source are placed in a vessel with an electrolyte - an electrolyzer, then an ionic current will begin to flow in it, and positively charged ions - cations will move towards the cathode (these are mainly metals and hydrogen), and negatively charged ions - anions ( chlorine, oxygen) - to the anode.

At the anode, the anions give up their charge and turn into neutral particles that settle on the electrode. At the cathode, cations take electrons from the electrode and are also neutralized, settling on it, and the gases released on the electrodes in the form of bubbles rise upward.

Figure: 1. Processes during electrolysis. Electrolysis bath circuit: 1 - bath, 2 - electrolyte, 3 - anode, 4 - cathode, 5 - power supply

The electric current in the external circuit is the movement of electrons from the anode to the cathode (Fig. 1). In this case, the solution is depleted, and to maintain the continuity of the electrolysis process it is necessary to enrich it. This is how the extraction of certain substances from the electrolyte (electroextraction) is carried out.

If the anode can dissolve in the electrolyte as the latter is depleted, then its particles, dissolving in the electrolyte, acquire a positive charge and are directed to the cathode, on which they are deposited, thereby transferring material from the anode to the cathode. Since the process is carried out so that the impurities contained in the metal of the anode are not transferred to the cathode, this process is called electrolytic refining.

If the electrode is placed in a solution with ions of the same substance from which it is made, then at a certain potential between the electrode and the solution, neither the electrode dissolution nor the substance from the solution is deposited on it.

This potential is called the normal potential of the substance. If a more negative potential is applied to the electrode, then the release of the substance (cathodic process) will begin on it, but if it is more positive, then its dissolution will begin (anodic process).

The value of normal potentials depends on the concentration of ions and temperature. It is generally accepted to consider the normal potential of hydrogen as zero. Table 1 shows the normal electrode potentials of some aqueous solutions of substances at + 25 ° C.

Table 1. Normal electrode potentials at + 25 ° С

If the electrolyte contains ions of different metals, then ions with a lower negative normal potential (copper, silver, lead, nickel) are released first at the cathode; alkaline earth metals are the most difficult to isolate. In addition, there are always hydrogen ions in aqueous solutions, which will be released earlier than all metals with a negative normal potential, therefore, during the electrolysis of the latter, a significant or even most of the energy is spent on hydrogen evolution.

By means of special measures, it is possible to prevent the evolution of hydrogen within known limits, however, metals with a normal potential of less than 1 V (for example, magnesium, aluminum, alkaline earth metals) cannot be obtained by electrolysis from an aqueous solution. They are obtained by decomposition of molten salts of these metals.

Normal electrode potentials of substances indicated in table. 1, are minimal, at which the electrolysis process begins, in practice, large values \u200b\u200bof the potential are required for the development of the process.

The difference between the actual potential of the electrode during electrolysis and the potential normal for it is called overvoltage. It increases energy losses during electrolysis.

On the other hand, increasing the overvoltage for hydrogen ions makes it difficult to release it at the cathode, which makes it possible to obtain by electrolysis from aqueous solutions a number of metals that are more negative than hydrogen, such as lead, tin, nickel, cobalt, chromium, and even zinc. This is achieved by conducting the process at increased current densities on the electrodes, as well as by introducing certain substances into the electrolyte.

The course of cathodic and anodic reactions during electrolysis is determined by the following two Faraday laws.

1. The mass of the substance m e released during electrolysis at the cathode or passed from the anode to the electrolyte is proportional to the amount of electricity passed through the electrolyte I τ : m e \u003d α / τ, here a is the electrochemical equivalent of the substance, g / C.

2. The mass of a substance released during electrolysis with the same amount of electricity is directly proportional to the atomic mass of substance A and inversely proportional to its valence n: m e \u003d A / 96480n, here 96480 is the Faraday number, C x mol -1.

Thus, the electrochemical equivalent of a substance α \u003d A / 96480n is the mass of a substance in grams, released by a unit of electricity passing through the electrolytic bath - a coulomb (ampere-second).

For copper A \u003d 63.54, n \u003d 2, α \u003d 63.54 / 96480 -2 \u003d 0.000329 g / C, for nickel α \u003d 0.000304 g / C, for zinc α \u003d 0.00034 g / C

In reality, the mass of the released substance is always less than the indicated one, which is explained by a number of side processes taking place in the bath (for example, hydrogen evolution at the cathode), current leaks and short circuits between the electrodes.

The ratio of the mass of the actually released substance to its mass, which should have been released according to Faraday's law, is called the current yield of the substance η1.

Therefore, for a real process m e \u003d η1x ( A / 96480n) x It

Naturally, always η1

The current efficiency significantly depends on the current density at the electrode. With an increase in the current density at the electrode, the current efficiency increases and the efficiency of the process increases.

Voltage U el, which must be supplied to the electrolyzer, consists of: decomposition voltage Ep (potential difference of the anodic and cathodic reactions), the sum of the anodic and cathodic overvoltages, the voltage drop in the electrolyte Ep, the voltage drop in the electrolyte U e \u003d IR ep (R ep is the electrolyte resistance ), voltage drop in tires, contacts, electrodes U c \u003d I (R w + R to + R e). We get: U el \u003d Ep + Ep + U e + U c.

The power consumed during electrolysis is equal to: Rel \u003d IU el \u003d I (Ep + Ep + U e + U s)

Of this power, only the first component is spent on carrying out reactions, the rest are heat losses of the process. Only in the electrolysis of molten salts, part of the heat released in the electrolyte IU e is used useful, since it is spent on melting the salts loaded into the electrolyzer.

The efficiency of the electrolysis bath can be estimated by the mass of the substance in grams, released per 1 J of consumed electricity. This value is called the energy yield of a substance. It can be found by the expression q e \u003d (αη1) / U el100,here α is the electrochemical equivalent of the substance, g / C, η1 is the current efficiency, U email - electrolyzer voltage, V.

An electrolyzer is a special device that is designed to separate the components of a compound or solution using an electric current. These devices are widely used in industry, for example, for obtaining active metal components from ore, purifying metals, applying metal coatings to products. They are rarely used for everyday life, but they are also found. In particular, for home use, devices are proposed that allow you to determine the pollution of water or to obtain the so-called "living" water.

The basis of the device's operation is the principle of electrolysis, the discoverer of which is the famous foreign scientist Faraday. However, the first electrolyzer of water 30 years before Faraday was created by a Russian scientist named Petrov. He proved in practice that water can be enriched in the cathodic or anodic state. Despite this injustice, his work was not in vain and served the development of technology. At the moment, numerous types of devices have been invented and are successfully used that work on the principle of electrolysis.

What is it

The electrolyzer is powered by an external power source that supplies electrical current. Simplified, the unit is made in the form of a housing in which two or more electrodes are mounted. There is an electrolyte inside the case. When an electric current is applied, the solution decomposes into the required components. Positively charged ions of one substance are directed to a negatively charged electrode and vice versa.

The main characteristic of such units is performance. That is, this is the amount of solution or substance that the installation can process over a certain period of time. This parameter is indicated in the model name. However, other indicators can also affect it: current strength, voltage, type of electrolyte, and so on.

Types and types

According to the design of the anode and the location of the current lead, the electrolyzer can be of three types, these are units with:

1. Pressed baked anodes.
2. Continuous self-baking anode, as well as side conductor.
3. Continuous self-baking anode and top conductor.

The electrolyzer used for solutions, according to its design features, can be conditionally divided into:

• Dry.
• Flowing.
• Membrane.
• Diaphragm.

Device

The designs of the units can be different, but they all work on the principle of electrolysis.

The device in most cases consists of the following elements:

• Electrically conductive housing.
• Cathode.
• Anode.
• Branch pipes designed for the input of electrolyte, as well as the output of substances obtained during the reaction.

The electrodes are sealed. Usually they are presented in the form of cylinders, which communicate with the external environment using pipes. The electrodes are made of special conductive materials. The metal is deposited on the cathode or ions of the separated gas are directed to it (during the splitting of water).

In the nonferrous industry, specialized electrolysis units are often used. These are more complex installations that have their own characteristics. So the electrolyzer for the separation of magnesium and chlorine requires a bath made of the walls of the end and longitudinal views. It is lined with refractory bricks and other materials, and is also divided by a partition into an electrolysis compartment and a cell in which the end products are collected.

The design features of each type of such equipment allow us to solve only specific problems that are associated with ensuring the quality of the released substances, the speed of the reaction, the energy consumption of the installation, and so on.

Operating principle

In electrolysis devices, only ionic compounds conduct electric current. Therefore, when the electrodes are lowered into the electrolyte and the electric current is turned on, an ionic current begins to flow in it. Positive particles in the form of cations are directed to the cathode, for example, these are hydrogen and various metals. Anions, that is, negatively charged ions, flow to the anode (oxygen, chlorine).

When approaching the anode, the anions lose their charge and become neutral particles. As a result, they are deposited on the electrode. At the cathode, similar reactions occur: cations take electrons from the electrode, which leads to their neutralization. As a result, cations are deposited on the electrode. For example, when water splits, hydrogen is formed, which rises upward in the form of bubbles. To collect this gas, special pipes are constructed above the cathode. Through them, hydrogen enters the required container, after which it can be used for its intended purpose.

The principle of operation in the designs of different devices is generally similar, but in some cases there may be some peculiarities. So in membrane units, a solid electrolyte is used in the form of a membrane, which has a polymer base. The main feature of such devices lies in the dual purpose of the membrane. This interlayer can transport protons and ions, including separating electrodes and end products of electrolysis.

Diaphragm devices are used in cases where diffusion of the end products of the electrolysis process cannot be allowed. For this purpose, a porous diaphragm is used, which is made of glass, asbestos or ceramics. In some cases, polymer fibers or glass wool can be used as such a diaphragm.

Application

Electrolysis is widely used in various industries. But, despite its simple design, it has a variety of designs and functions. This equipment is used for:

• Extraction of non-ferrous metals (magnesium, aluminum).
• Receipt chemical elements (decomposition of water into oxygen and hydrogen, obtaining chlorine).
• Cleaning wastewater (desalination, disinfection, disinfection from metal ions).
• Processing of various products (demineralization of milk, salting of meat, electrical activation of food liquids, extraction of nitrates and nitrites from vegetable products, extraction of protein from algae, mushrooms and fish waste).

In medicine, devices are used in intensive care to detoxify the human body, that is, to create high-purity sodium hypochlorite solutions. For this, a flow-through device with titanium electrodes is used.

Electrolysis and electrodialysis plants are widely used to solve environmental issues and water desalination. But these units, in view of their shortcomings, are rarely used: this is the complexity of the design and their operation, the need for a three-phase current and the requirement for periodic replacement of electrodes due to their dissolution.

Similar installations are used in everyday life, for example, to obtain "living" water, as well as its purification. In the future, it is possible to create miniature installations that will be used in cars for the safe production of hydrogen from water. Hydrogen will become a source of energy, and the car can be filled with ordinary water.

If two electrodes are lowered into the electrolyte and connected to a power source, then negatively charged ions (anions) in the electrolyte will begin to be attracted to the positive electrode (anode), and positively charged ions (cations) - to the negative electrode (cathode) - a direct current will appear in the circuit.

Cations, having reached the cathode surface, will attach to themselves the electrons of the metal (recover); the anions at the anode will donate their electrons (oxidize).

The figure above shows the simplest case of electrolysis - in the melt sodium chloride dissociates into sodium cations and chlorine anions. Under the action of an electric current, Na + is reduced at the cathode, Cl - - are oxidized at the anode.

The electrolysis equation will be:

2Na + + Cl - \u003d 2Na 0 + Cl 2 0 2NaCl \u003d 2Na + Cl

As a result of electrolysis, chlorine gas will be released at the anode, and metallic sodium at the cathode.

The redox reaction occurring during electrolysis proceeds due to electrical energy - without an external source of energy, it will be impossible.

It should be noted that electrolysis in solution electrolyte and electrolysis in melt electrolyte are slightly different things.

The nuance lies in the fact that in an aqueous electrolyte solution, in addition to metal ions and an acid residue, there are also water dissociation products, which must be taken into account.

Electrolysis rules for aqueous solutions

• Electrolysis at the cathode depends only on positions of the metal in the electrochemical series of voltages:
  • if the electrolyte cation is to the left of aluminum (inclusive), water is reduced at the cathode with the release of hydrogen, and the metal cations remain in solution:
    2H 2 O + 2e - \u003d H 2 + 2OH - (Li ... Al)
  • if the electrolyte cation stands between aluminum and hydrogen, both water and metal cations are reduced at the cathode;
    Me n + + ne - \u003d Me 0; 2H 2 O + 2e - \u003d H 2 + 2OH - (Mn ... Pb)
  • if the electrolyte cation is to the right of the hydrogen, only metal cations are reduced at the cathode:
    Me n + + ne - \u003d Me 0 (Cu ... Au)
  • if there are several metals in the electrolyte solution, the first to be reduced are metal cations, which in the series of voltages is to the right of the others.
• Anode electrolysis depends only on materialfrom which the anode is made:
  • in the case of a soluble anode (metals that are oxidized during the electrolysis process - iron, copper, zinc, silver) - the process of oxidation of the anode metal is always going on:
    Me 0 -ne - \u003d Me n +
  • in the case of an insoluble anode (gold, platinum, graphite):
    • anion is oxidized during the electrolysis of solutions of salts of anoxic acids, with the exception of fluorides:
      Ac m -me - \u003d Ac 0
    • there is a process of water oxidation in other cases (electrolysis of hydroxy acids and fluorides) - the anion remains in solution:
      2H 2 O-4e - \u003d 4H + + O 2
    • during electrolysis of alkali solutions, hydroxide ions are oxidized:
      4OH - -4e - \u003d 2H 2 O + O 2
  • the reducing activity of anions decreases in the series (correspondingly, the ability to oxidize increases): I -; Br -; S 2-; Cl -; OH -; SO 4 2-; NO 3 -; F -

Industrial application of electrolysis

• Isolation and purification of metals.
• Obtaining aluminum, magnesium, sodium, cadmium.
• Getting alkalis, chlorine, hydrogen.
• Purification of copper, nickel, lead.
• Processes for spraying protective coatings to protect metals from corrosion.

Examples of solving problems for electrolysis

1. Write the equation of electrolysis of a potassium chloride solution for an insoluble anode.

• KCl → K + + Cl -
• electrolysis at the anode (+):
  2Cl - -2e - \u003d Cl 2 0
• cathode electrolysis (-):
  2H 2 O + 2e - \u003d H 2 + 2OH -
• Total ionic equation:
  2H 2 O + 2Cl - \u003d H 2 + Cl 2 + 2OH -
• Molecular Equation:
  2KCl + 2H 2 O \u003d H 2 + Cl 2 + 2KOH

2. Write the equation of electrolysis of a potassium chloride solution for a copper (soluble) anode.

• KCl → K + + Cl -
• anode (+):
  Cu 0 -2e - \u003d Cu 2+
• copper ions during electrolysis are transferred from the anode to the cathode (separation of pure copper at the cathode):
  Cu 2+ + 2e - \u003d Cu 0
• The concentration of potassium chloride in the solution remains constant, therefore, the total electrolysis equation for the soluble anode cannot be written.

3. Write the equation of electrolysis of sodium hydroxide solution.

• NaOH → Na + + OH -
• electrolysis at the anode (+):
  4OH - + 4e - \u003d O 2 + 2H 2 O
• cathode electrolysis (-):
  2H 2 O + 2e - \u003d H 2 + 2OH -
• Sum equations:
  4H 2 O + 4OH - \u003d 2H 2 + O 2 + 4OH - + 2H 2 O
  2H 2 O \u003d 2H 2 + O 2

4. Write the equation of electrolysis of zinc chloride solution with carbon electrodes.

• ZnCl 2 → Zn 2+ + 2Cl -
• electrolysis at the anode (+):
  2Cl - -2e - \u003d Cl 2
• cathode(-):
  Zn 2+ + 2e - \u003d Zn 0
  2H 2 O + 2e - \u003d H 2 + 2OH -
• The total equation of electrolysis cannot be written, since it is not known how much electricity is spent on the reduction of water, and how much - on the reduction of zinc ions.

5. Write the equation of electrolysis of an aqueous solution of copper (II) and silver nitrates with insoluble electrodes.

• Cu (NO 3) 2 → Cu 2+ + 2NO 3 -
  AgNO 3 → Ag + + NO 3 -
• electrolysis at the anode (+):
  2H 2 O-4e - \u003d O 2 + 4H +
• electrolysis at the cathode (-):
  Cu 2+ + 2e - \u003d Cu 0
  Ag + + e - \u003d Ag 0
• According to the position of metals in the series of voltages (see above), silver cations will be reduced first, copper cations - last.
• Ionic equations:
  4Ag + + 2H 2 O \u003d 4Ag 0 + O 2 + 4H +
  2Cu 2+ + 2H 2 O \u003d 2Cu 0 + O 2 + 4H +
• Molecular Equations:
  4AgNO 3 + 2H 2 O \u003d 4Ag + O 2 + 4HNO 3
  2Cu (NO 3) 2 + 2H 2 O \u003d 2Cu + O 2 + 4HNO 3

Electrolysis is widely used in the industrial field, for example, for the production of aluminum (apparatus with baked anodes RA-300, RA-400, RA-550, etc.) or chlorine (industrial plants Asahi Kasei). In everyday life, this electrochemical process was used much less often, as an example an Intellichlor pool electrolyzer or a Star 7000 plasma welding machine. The increase in the cost of fuel, gas tariffs and heating radically changed the situation, making the idea of \u200b\u200bwater electrolysis popular at home. Let's consider what devices for splitting water (electrolyzers) are, and what their design is, as well as how to make a simple apparatus with your own hands.

What is an electrolyser, its characteristics and application

This is the name of the device for the electrochemical process of the same name, which requires external source nutrition. Structurally, this apparatus is a bath filled with electrolyte, in which two or more electrodes are placed.

The main characteristic of such devices is performance, often this parameter is indicated in the name of the model, for example, in stationary electrolysis plants SEU-10, SEU-20, SEU-40, MBE-125 (membrane block electrolysers), etc. In these cases, the numbers indicate the production of hydrogen (m 3 / h).

As for the rest of the characteristics, they depend on the specific type of device and the scope of application, for example, when water electrolysis is carried out, the following parameters affect the efficiency of the installation:

Thus, applying 14 volts to the outputs, we will get 2 volts for each cell, while on the plates on each side there will be different potentials. Electrolyzers using a similar plate connection system are called dry cells.

1. The distance between the plates (between the cathode and anode spaces), the smaller it is, the less resistance will be and, therefore, more current will pass through the electrolyte solution, which will lead to an increase in gas production.
2. The dimensions of the plate (meaning the area of \u200b\u200bthe electrodes) are directly proportional to the current flowing through the electrolyte, and therefore also have an effect on performance.
3. Electrolyte concentration and its thermal balance.
4. Characteristics of the material used to make the electrodes (gold is an ideal material, but too expensive, so stainless steel is used in homemade circuits).
5. The use of process catalysts, etc.

As mentioned above, plants of this type can be used as a hydrogen generator for the production of chlorine, aluminum or other substances. They are also used as devices for the purification and disinfection of water (UPEV, VGE), as well as a comparative analysis of its quality (Tesp 001).

We are primarily interested in devices that produce Brown's gas (hydrogen with oxygen), since it is this mixture that has all the prospects for use as an alternative energy carrier or additives to fuel. We will consider them a little later, but for now let's move on to the design and principle of operation of the simplest electrolyzer that splits water into hydrogen and oxygen.

Device and detailed operating principle

Devices for the production of oxyhydrogen gas, for safety reasons, do not imply its accumulation, that is, the gas mixture is burned immediately after production. This simplifies the design somewhat. In the previous section, we considered the main criteria that affect the performance of the device and impose certain requirements for performance.

The principle of operation of the device is shown in Figure 4, a constant voltage source is connected to electrodes immersed in an electrolyte solution. As a result, a current begins to pass through it, the voltage of which is higher than the decomposition point of water molecules.

Figure 4. Construction of a simple electrolyzer

As a result of this electrochemical process, the cathode releases hydrogen and the anode oxygen, in a 2 to 1 ratio.

Types of electrolysers

Let's briefly get acquainted with the design features of the main types of devices for splitting water.

Dry

The design of this type of device was shown in Figure 2, its peculiarity lies in the fact that by manipulating the number of cells, it is possible to power the device from a source with a voltage significantly exceeding the minimum electrode potential.

Flowing

A simplified device of this type of devices can be found in Figure 5. As you can see, the design includes a bath with electrodes "A", completely filled with a solution and a tank "D".

Fig 5. Design of a flow cell

The principle of operation of the device is as follows:

• at the entrance of the electrochemical process, the gas together with the electrolyte is squeezed out into the container "D" through the pipe "B";
• in the tank "D" there is a separation from the electrolyte solution of the gas, which is discharged through the outlet valve "C";
• the electrolyte is returned to the hydrolysis bath through pipe “E”.

Membrane

The main feature of this type of device is the use of a solid electrolyte (membrane) on a polymer basis. The design of devices of this type can be found in Figure 6.

Fig 6. Membrane type electrolyzer

The main feature of such devices is the double purpose of the membrane, it not only transfers protons and ions, but also at the physical level separates both electrodes and products of the electrochemical process.

Diaphragm

In cases where the diffusion of electrolysis products between the electrode chambers is not permissible, a porous diaphragm is used (which gave the name to such devices). The material for it can be ceramics, asbestos or glass. In some cases, polymer fibers or glass wool can be used to create such a diaphragm. Figure 7 shows the simplest version of a diaphragm device for electrochemical processes.

Explanation:

1. Oxygen outlet.
2. U-shaped flask.
3. Hydrogen outlet.
4. Anode.
5. Cathode.
6. Diaphragm.

Alkaline

The electrochemical process is impossible in distilled water; a concentrated alkali solution is used as a catalyst (the use of salt is undesirable, since chlorine is liberated). Based on this, most electrochemical devices for splitting water can be called alkaline.

On thematic forums, it is advised to use sodium hydroxide (NaOH), which, unlike baking soda (NaHCO 3), does not corrode the electrode. Note that the latter has two significant advantages:

1. Iron electrodes can be used.
2. No harmful substances are released.

But, one significant drawback negates all the benefits of baking soda as a catalyst. Its concentration in water is not more than 80 grams per liter. This reduces the frost resistance of the electrolyte and its current conductivity. If you can still put up with the first in the warm season, then the second requires an increase in the area of \u200b\u200bthe electrode plates, which in turn increases the size of the structure.

Electrolyzer for hydrogen production: drawings, diagram

Consider how you can make a powerful gas burner that runs on a mixture of hydrogen and oxygen. A diagram of such a device can be seen in Figure 8.

Figure: 8. Device of a hydrogen burner

Explanation:

1. Burner nozzle.
2. Rubber tubes.
3. Second water seal.
4. The first water seal.
5. Anode.
6. Cathode.
7. Electrodes.
8. Electrolyzer bath.

Figure 9 shows a schematic diagram of the power supply for the electrolyser of our burner.

Figure: 9. Power supply for electrolysis burner

We need the following parts for a powerful rectifier:

• Transistors: VT1 - MP26B; VT2 - P308.
• Thyristors: VS1 - KU202N.
• Diodes: VD1-VD4 - D232; VD5 - D226B; VD6, VD7 - D814B.
• Capacitors: 0.5 uF.
• Variable resistors: R3 -22 kOhm.
• Resistors: R1 - 30 kOhm; R2 - 15 kΩ; R4 - 800 Ohm; R5 - 2.7 kOhm; R6 - 3 kOhm; R7 - 10 kOhm.
• PA1 - ammeter with a measurement scale of at least 20 A.

Brief instructions for electrolyzer parts.

The bath can be made from an old battery. The plates should be cut 150x150 mm from roofing iron (sheet thickness 0.5 mm). To work with the above-described power supply, you will need to assemble an electrolyzer for 81 cells. The drawing used for installation is shown in Figure 10.

Figure: 10. Drawing of the electrolyzer for a hydrogen burner

Note that the maintenance and management of such a device is not difficult.

DIY electrolyser for a car

On the Internet you can find many schemes of HHO systems, which, according to the authors, can save from 30% to 50% of fuel. Such statements are too optimistic and, as a rule, are not supported by any evidence. A simplified diagram of such a system is shown in Figure 11.

Simplified electrolyser diagram for a car

In theory, such a device should reduce fuel consumption due to its complete burnout. For this, Brown's mixture is fed into the air filter of the fuel system. It is hydrogen with oxygen, obtained from an electrolyzer powered by the vehicle's internal network, which increases fuel consumption. Vicious circle.

Of course, the PWM circuit of the current regulator can be used, a more efficient switching power supply or other tricks can be used to reduce power consumption. Sometimes on the Internet you come across offers to purchase a low-current power supply unit for an electrolyzer, which is generally nonsense, since the performance of the process directly depends on the current strength.

It's like the Kuznetsov system, the water activator of which is lost, but the patent is missing, etc. In the above videos, where they talk about the indisputable advantages of such systems, there are practically no reasoned arguments. This does not mean that the idea has no right to exist, but the claimed economy is "slightly" exaggerated.

DIY electrolyzer for home heating

At the moment, it makes no sense to make a homemade electrolyser for heating a house, since the cost of hydrogen obtained by electrolysis is much more expensive than natural gas or other heat carriers.

It should also be borne in mind that no metal can withstand the combustion temperature of hydrogen. True, there is a solution, patented by Stan Martin, to get around this problem. It is necessary to pay attention to the key point that allows you to distinguish a worthy idea from obvious delusion. The difference between them is that the first one is issued a patent, and the second one finds its supporters on the Internet.

This could be the end of the article on household and industrial electrolysers, but it makes sense to make a small overview of the companies that produce these devices.

Electrolyzer manufacturers overview

We list the manufacturers that produce fuel cells based on electrolysers, some companies also produce household devices: NEL Hydrogen (Norway, on the market since 1927), Hydrogenics (Belgium), Teledyne Inc (USA), Uralkhimmash (Russia), RusAl (Russia, significantly improved the Soderberg technology), RutTech (Russia).