Methods for producing hydrogen in industrial conditions
Extraction by methane conversion
... Water in a vapor state, preheated to 1000 degrees Celsius, is mixed with methane under pressure and in the presence of a catalyst. This method is interesting and proven, it should also be noted that it is constantly being improved: the search for new catalysts, cheaper and more effective, is underway.
Consider the most ancient method of producing hydrogen - coal gasification
... In the absence of air access and a temperature of 1300 degrees Celsius, coal and water vapor are heated. Thus, hydrogen is displaced from water, and carbon dioxide is obtained (hydrogen will be at the top, carbon dioxide, also obtained as a result of the reaction, is at the bottom). This will be the separation of the gas mixture, everything is very simple.
Obtaining hydrogen by electrolysis of water
is considered the simplest option. For its implementation, it is necessary to pour a soda solution into the container, and also place two electrical elements there. One will be charged positively (anode) and the other negatively (cathode). When current is applied, hydrogen will go to the cathode and oxygen to the anode.
Obtaining hydrogen by the method partial oxidation
... For this, an alloy of aluminum and gallium is used. It is placed in water, which leads to the formation of hydrogen and alumina during the reaction. Gallium is necessary for the reaction to occur in full (this element will prevent aluminum from oxidizing prematurely).
Recently acquired relevance method of using biotechnology
: under the condition of a lack of oxygen and sulfur, chlamydomonas begin to intensively release hydrogen. A very interesting effect that is now being actively studied.
Do not forget another old, proven method of hydrogen production, which consists in using different alkaline elements
and water. In principle, this technique is feasible in a laboratory setting with the necessary safety measures in place. Thus, in the course of the reaction (it proceeds with heating and with catalysts), a metal oxide and hydrogen are formed. It remains only to collect it.
Get hydrogen by interaction of water and carbon monoxide
possible only in an industrial environment. Carbon dioxide and hydrogen are formed, the principle of their separation is described above.
The scope of the hydrogen generator
H2 is a modern energy carrier that is actively used in many industrial areas. Here are just a few:
- production of hydrogen chloride (HC) l;
- production of fuel for rocket launchers;
- production of ammonia;
- metal processing and cutting on it;
- development of fertilizers for summer cottages;
- synthesis of nitric acid;
- the creation of methyl alcohol;
- food industry;
- hydrochloric acid production;
- creation of warm floor systems.
In addition, HHO has become very useful in everyday life, albeit with reservations. First of all, it is used for autonomous heating systems. In addition, Brown's gas is added to gasoline in an attempt to trick the engine and save on fuel.
Both cases have their own peculiarities. So, when organizing home heating, you need to take into account that the combustion temperature of HHO is an order of magnitude higher than that of methane. In this regard, it is necessary to purchase a special, expensive boiler with a heat-resistant nozzle. Otherwise, the owner and his home will be in considerable danger.
THE INVENTION HAS THE FOLLOWING ADVANTAGES
The heat obtained from the oxidation of gases can be used directly on site, and hydrogen and oxygen are obtained from the disposal of waste steam and process water.
Low water consumption when generating electricity and heat.
The simplicity of the way.
Significant energy savings as it is spent only on warming up the starter to the established thermal regime.
High productivity of the process, because dissociation of water molecules lasts tenths of a second.
Explosion and fire safety of the method, because in its implementation, there is no need for containers for collecting hydrogen and oxygen.
During the operation of the installation, water is repeatedly purified, being converted into distilled water. This eliminates sediments and limescale, which increases the service life of the installation.
The installation is made of ordinary steel; with the exception of boilers made of heat-resistant steels with lining and shielding of their walls. That is, no special expensive materials are required.
The invention can find application in
industry by replacing hydrocarbon and nuclear fuel in power plants with cheap, widespread and environmentally friendly water, while maintaining the power of these plants.
Hydrogen at home: is there a benefit
We note right away: it is unprofitable to use a hydrogen generator to heat a house. You will spend more electricity producing pure H2 than you will receive energy after burning it. So, for 1 kW of heat, 2 kW of electricity is spent, that is, there is no benefit. It is easier to install any of the electric boilers at home.
To replace 1 liter of gasoline for a car, you will need 4766 liters of pure hydrogen or 7150 liters of oxyhydrogen gas, 1/3 of which is oxygen. So far, even the best minds in the world have not developed a unit capable of delivering such performance.
CLAIM
Method for producing hydrogen and oxygen from water vapor
, including passing this steam through an electric field, characterized in that they use superheated water steam with a temperature
500 - 550 o C
, passed through a high voltage direct current electric field to dissociate vapor and separate it into hydrogen and oxygen atoms.
I have long wanted to do a similar thing. But further experiments with a battery and a pair of electrodes did not reach. I wanted to make a full-fledged apparatus for the production of hydrogen, in quantities to inflate a balloon. Before making a full-fledged apparatus for electrolysis of water at home, I decided to check everything on the model.
The general scheme of the electrolyzer looks like this.
This model is not suitable for full daily use. But we managed to test the idea.
So I decided to use graphite for the electrodes. An excellent source of graphite for electrodes is the trolley bus collector. There are plenty of them lying around at the end stops. It must be remembered that one of the electrodes will collapse.
We saw and finalize with a file. The intensity of electrolysis depends on the strength of the current and the area of the electrodes.
Wires are attached to the electrodes. The wires must be carefully insulated.
For the case of the electrolyzer model, plastic bottles are quite suitable. Holes are made in the cover for pipes and wires.
Everything is thoroughly coated with sealant.
Cut-off bottle necks are suitable for connecting two containers.
They need to be joined together and the seam must be melted.
The nuts are made from bottle caps.
Holes are made in two bottles at the bottom. Everything is connected and carefully filled with sealant.
We will use a 220V household network as a voltage source. I want to warn you that this is a rather dangerous toy. So, if you do not have sufficient skills or there are doubts, then it is better not to repeat.In the household network, we have an alternating current, for electrolysis it must be straightened. A diode bridge is perfect for this. The one in the photo was not powerful enough and quickly burned out. The best option was the Chinese MB156 diode bridge in an aluminum case.
The diode bridge gets very hot. Active cooling will be required. A cooler for a computer processor is perfect. A junction box of a suitable size can be used for the enclosure. Sold in electrical goods.
Several layers of cardboard must be placed under the diode bridge.
The necessary holes are made in the cover of the junction box.
This is what the assembled unit looks like. The electrolyzer is powered from the mains, the fan is powered by a universal power source. A baking soda solution is used as an electrolyte. Here it must be remembered that the higher the concentration of the solution, the higher the reaction rate. But at the same time, the heating is also higher. Moreover, the reaction of sodium decomposition at the cathode will contribute to the heating. This reaction is exothermic. As a result, hydrogen and sodium hydroxide will be formed.
The device in the photo above was very hot. It had to be turned off periodically and wait until it cools down. The heating problem was partially solved by cooling the electrolyte. For this I used a tabletop fountain pump. A long tube runs from one bottle to another through a pump and a bucket of cold water.
The relevance of this issue today is quite high due to the fact that the sphere of using hydrogen is extremely extensive, and in its pure form it is practically not found anywhere in nature. That is why several techniques have been developed that allow the extraction of this gas from other compounds through chemical and physical reactions. This is discussed in the article above.
Obtaining hydrogen and checking it for purity
Hydrogen can be obtained by reacting zinc and hydrochloric acid.
Zn + 2HCl = ZnCl2 + H2 ↑
Zinc displaces hydrogen from acids, like all metals standing in the series of voltages to the left of hydrogen.
To collect hydrogen in a test tube, you need to turn it upside down, because hydrogen is lighter than air and tends upward. This method of collecting hydrogen is called the "air displacement method."
Fig. 1. Obtaining hydrogen and collecting it by air displacement
The test tube accumulates hydrogen, but it also contains air, and therefore oxygen. Hydrogen and oxygen are explosive mixtures. We ignite the collected hydrogen with a splinter. The test tube is small and the explosion of hydrogen and oxygen is just a sharp bang. The less oxygen in the mixture, the quieter the cotton.
If the hydrogen collected in the test tube is pure, then we will hear a dull pop. Such hydrogen can be ignited.
Household hydrogen production
Electrolyzer selection
To obtain an element of the house, you need a special apparatus - an electrolyser. There are many options for such equipment on the market, devices are offered by both well-known technology corporations and small manufacturers. Branded units are more expensive, but the build quality is higher.
The home appliance is small and easy to use. Its main details are:
Electrolyzer - what is it
- reformer;
- cleaning system;
- fuel cells;
- compressor equipment;
- a container for storing hydrogen.
Simple tap water is taken as raw material, and electricity comes from a regular outlet. Solar-powered units save on electricity.
Home hydrogen is used in heating or cooking systems. And also they enrich the fuel-air mixture in order to increase the power of the car's engines.
Making an apparatus with your own hands
It is even cheaper to make the device yourself at home.A dry cell looks like a sealed container, which consists of two electrode plates in a container with an electrolytic solution. The World Wide Web offers a variety of assembly schemes for devices of different models:
- with two filters;
- with top or bottom arrangement of the container;
- with two or three valves;
- with galvanized board;
- on the electrodes.
Electrolysis device diagram
It is not difficult to create a simple device for producing hydrogen. It will require:
- sheet stainless steel;
- transparent tube;
- fittings;
- plastic container (1.5 l);
- water filter and non-return valve.
The device of a simple device for producing hydrogen
In addition, various hardware will be needed: nuts, washers, bolts. The first step is to cut the sheet into 16 square compartments, cut off a corner from each of them. In the opposite corner from it, you need to drill a hole for bolting the plates. To ensure constant current, the plates must be connected according to the plus – minus – plus – minus scheme. These parts are isolated from each other with a tube, and at the connection with a bolt and washers (three pieces between the plates). 8 plates are placed on plus and minus.
When properly assembled, the ribs of the plates will not touch the electrodes. The assembled parts are lowered into a plastic container. At the point where the walls touch, two mounting holes are made with bolts. Install a safety valve to remove excess gas. Fittings are mounted in the container lid and the seams are sealed with silicone.
Testing the apparatus
To test the device, perform several actions:
Hydrogen production scheme
- Fill with liquid.
- Covering with a lid, connect one end of the tube to the fitting.
- The second is immersed in water.
- Connect to a power source.
After plugging the device into an outlet, after a few seconds, the electrolysis process and precipitation will be noticeable.
Pure water does not have good electrical conductivity. To improve this indicator, you need to create an electrolytic solution by adding an alkali - sodium hydroxide. It is found in pipe cleaning compounds like the Mole.
Methods for producing hydrogen
Hydrogen is a colorless and odorless gaseous element with a density of 1/14 relative to air. In a free state, it is rare. Usually hydrogen is combined with other chemical elements: oxygen, carbon.
Hydrogen production for industrial needs and power engineering is carried out by several methods. The most popular are:
- electrolysis of water;
- concentration method;
- low temperature condensation;
- adsorption.
Hydrogen can be isolated not only from gaseous or water compounds. Hydrogen is produced by exposing wood and coal to high temperatures, as well as by processing biowaste.
Atomic hydrogen for power engineering is obtained using the method of thermal dissociation of a molecular substance on a wire made of platinum, tungsten or palladium. It is heated in a hydrogen atmosphere under a pressure of less than 1.33 Pa. And also radioactive elements are used to obtain hydrogen.
Thermal dissociation
Electrolysis method
The simplest and most popular method of hydrogen evolution is water electrolysis. It allows the production of practically pure hydrogen. Other advantages of this method are:
The principle of operation of the electrolysis hydrogen generator
- availability of raw materials;
- receiving an element under pressure;
- the ability to automate the process due to the lack of moving parts.
The procedure for splitting a liquid by electrolysis is the reverse of the combustion of hydrogen. Its essence is that under the influence of direct current, oxygen and hydrogen are released on the electrodes dipped in an aqueous electrolyte solution.
An additional advantage is considered to be the production of by-products with industrial value.Thus, a large amount of oxygen is needed to catalyze technological processes in the energy sector, clean up soil and water bodies, and dispose of household waste. Heavy water obtained during electrolysis is used in power engineering in nuclear reactors.
Hydrogen production by concentration
This method is based on the separation of an element from gas mixtures containing it. Thus, the largest part of the industrially produced substance is extracted using steam reforming of methane. Hydrogen extracted in this process is used in energy, oil refining, rocket-building industries, as well as for the production of nitrogen fertilizers. The process of obtaining H2 is carried out in different ways:
- short-cycle;
- cryogenic;
- membrane.
The latter method is considered the most effective and less costly.
Low temperature condensation
This method of obtaining H2 consists in strong cooling of gaseous compounds under pressure. As a result, they are transformed into a two-phase system, which is subsequently separated by a separator into a liquid component and a gas. Liquid media are used for cooling:
- water;
- liquefied ethane or propane;
- liquid ammonia.
This procedure is not as easy as it sounds. It will not be possible to cleanly separate hydrocarbon gases at once. Some of the components will leave with gas taken from the separation compartment, which is not economical. The problem can be solved by deep cooling of the raw material before separation. But this requires a lot of energy.
In modern low temperature condenser systems, demethanization or deethanization columns are additionally provided. The gas phase is removed from the last separation stage, and the liquid is sent to the distillation column with a stream of raw gas after heat exchange.
Adsorption method
During adsorption, to release hydrogen, adsorbents are used - solids that absorb the necessary components of the gas mixture. Activated carbon, silicate gel, zeolites are used as adsorbents. To carry out this process, special devices are used - cyclic adsorbers or molecular sieves. When implemented under pressure, this method can recover 85% hydrogen.
If we compare adsorption with low-temperature condensation, we can note a lower material and operational cost of the process - on average, by 30 percent. Hydrogen is produced by adsorption for power engineering and with the use of solvents. This method allows the extraction of 90 percent of H2 from the gas mixture and obtaining the final product with a hydrogen concentration of up to 99.9%.
