How is coal produced. Coal and oil. Required time to "create" coal, oil

Since ancient times, mankind has been using coal as one of the sources of energy. And today this mineral is used quite widely. Sometimes it is called solar energy, which is preserved in stone.

Application

Coal is burned to produce heat that is used for hot water and home heating. The mineral is used in the technological processes of metal smelting. Thermal power plants convert coal into electricity by burning it.

Scientific advances have made it possible to use this valuable substance in a different way. Yes, in chemical industry a technology has been successfully mastered that makes it possible to obtain liquid fuel from coal, as well as such rare metals as germanium and gallium. From a valuable fossil, carbon-graphite with a high carbon concentration is currently being extracted. Methods have also been developed for producing plastics and high-calorie gaseous fuels from coal.

A very low fraction of low-grade coal and its dust are pressed into briquettes after processing. This material is great for heating private houses and industrial premises. In general, more than four hundred items of various products are produced after chemical processing, which coal is subjected to. The price of all these products is ten times higher than the cost of raw materials.

Over the past few centuries, mankind has been actively using coal as a fuel necessary for obtaining and converting energy. Moreover, the need for this valuable mineral has been increasing in recent years. This is facilitated by the development of the chemical industry, as well as the need for valuable and rare elements obtained from it. In this regard, intensive exploration of new deposits is currently underway in Russia, mines and quarries are being created, enterprises are being built to process this valuable raw material.

Fossil origin

In ancient times, the Earth had a warm and humid climate, in which a variety of vegetation flourished. From it coal was later formed. The origin of this fossil lies in the accumulation of billions of tons of dead vegetation at the bottom of the swamps, where they were covered with sediment. About 300 million years have passed since then. Under the powerful pressure of sand, water and various rocks, vegetation slowly decomposed in an oxygen-free environment. Under the influence of high temperatures, which were given by the closely located magma, this mass solidified, which gradually turned into coal. The origin of all existing deposits has only such an explanation.

Mineral reserves and its extraction

There are large deposits of coal on our planet. In total, according to experts, the earth's bowels store fifteen trillion tons of this mineral. Moreover, the extraction of coal in terms of its volume is in the first place. It is 2.6 billion tons per year, or 0.7 tons per inhabitant of our planet.

Coal deposits in Russia are located in various regions. Moreover, in each of them, the mineral has different characteristics and has its own depth of occurrence. Below is a list that includes the largest coal deposits in Russia:

1. It is located in the southeastern part of Yakutia. The depth of coal in these places allows for open-pit mining. This does not require special costs, which affects the reduction in the cost of the final product.
2. Tuva deposit. According to experts, there are about 20 billion tons of minerals on its territory. The field is very attractive for development. The fact is that eighty percent of its deposits are located in one layer, which has a thickness of 6-7 meters.
3. Minusinsk deposits. They are located in the Republic of Khakassia. These are several deposits, the largest of which are Chernogorskoye and Izykhskoye. Pool stocks are small. According to experts, they range from 2 to 7 billion tons. Coal, which is very valuable in terms of its characteristics, is mined here. The properties of the mineral are such that when it is burned, a very high temperature is recorded.
4. This deposit, located in the west of Siberia, gives a product used in ferrous metallurgy. The coal that is mined in these places goes for coking. The volume of deposits here is simply huge.
5. This deposit gives a product of the highest quality. The greatest depth of mineral deposits reaches five hundred meters. Mining is carried out both in open cuts and in mines.

Hard coal in Russia is mined in the Pechora coal basin. Deposits are also being actively developed in the Rostov region.

The choice of coal for the production process

In various industries, there is a need for different grades of minerals. What are the differences between hard coal? The properties and quality characteristics of this product vary widely.

This happens even if the coal has the same marking. The fact is that the characteristics of a fossil depend on the place of its extraction. That is why each enterprise, choosing coal for its production, should familiarize itself with its physical characteristics.

Properties

Coal differs in the following properties:

Degree of enrichment

Depending on the purpose of use, various hard coal can be purchased. In this case, the properties of the fuel become clear, based on the degree of its enrichment. Allocate:

1. Concentrates. Such fuel is used in the production of electricity and heat.

2. Industrial products. They are used in metallurgy.

3. fine fraction of coal (up to six millimeters), as well as dust resulting from rock crushing. Briquettes are formed from the sludge, which have good performance properties for household solid fuel boilers.

Degree of coalification

According to this indicator, there are:

1. Brown coal. This is the same coal, only partially formed. Its properties are somewhat worse than those of higher quality fuel. Brown coal produces low heat during combustion and crumbles during transportation. In addition, it has a tendency to spontaneous combustion.

2. Coal. This type of fuel has a large number of grades (brands), the properties of which are different. It is widely used in energy and metallurgy, housing and communal services and the chemical industry.

3. Anthracites. This is the highest quality type of coal.

The properties of all these forms of minerals differ significantly from each other. So, brown coal is characterized by the lowest calorific value, and anthracites are the highest. What is the best coal to buy? The price must be economically feasible. Based on this, the cost and specific heat are in the optimal ratio for ordinary coal (within $ 220 per ton).

Size classification

When choosing coal, it is important to know its dimensions. This indicator is encrypted in the grade of the mineral. So, coal happens:

- "P" - slab, which is large pieces over 10 cm.

- "K" - large, the size of which is from 5 to 10 cm.

- "O" - a nut, it is also quite large, with fragment sizes from 2.5 to 5 cm.

- "M" - small, with small pieces of 1.3-2.5 cm.

- "C" - a seed - a cheap fraction for long-term smoldering with dimensions of 0.6-1.3 cm.

- "Sh" - shtyb, which is mostly coal dust, intended for briquetting.

- "P" - ordinary, or non-standard, in which there may be fractions of various sizes.

Brown coal properties

This is the lowest quality coal. Its price is the lowest (about one hundred dollars per ton). formed in ancient swamps by pressing peat at a depth of about 0.9 km. This is the cheapest fuel containing a large amount of water (about 40%).

In addition, brown coal has a rather low heat of combustion. It contains a large amount (up to 50%) of volatile gases. If you use brown coal for the furnace, then in terms of its quality characteristics it will resemble raw firewood. The product burns heavily, smokes heavily and leaves behind a large amount of ash. Briquettes are often prepared from this raw material. They have good performance characteristics. Their price is in the range of eight to ten thousand rubles per ton.

Properties of hard coal

This fuel is of better quality. Coal is a rock that is black in color and has a matte, semi-gloss or shiny surface.

This type of fuel contains only five to six percent moisture, which is why it has a high calorific value. Compared to oak, alder and birch firewood, coal gives 3.5 times more heat. The disadvantage of this type of fuel is its high ash content. The price of coal in summer and autumn ranges from 3900 to 4600 rubles per ton. In winter, the cost of this fuel increases by twenty to thirty percent.

Coal storage

If the fuel is to be used during long term, then it must be placed in a special shed or bunker. There it must be protected from direct sun rays and from precipitation.

If the heaps of coal are large, then during storage it is necessary to constantly monitor their condition. Fine fractions in combination with high temperature and moisture can ignite spontaneously.

For almost 200 years, humanity has been using reserves that have been formed for hundreds of millions of years. Such wastefulness will someday lead us to collapse and an energy crisis, until we begin to take better care of our resources. For a better understanding, it would be worth knowing how coal was formed and how many years the proven reserves will last.

The need for energy

All industries need constant source of energy:

• Energy is released during the combustion of hydrocarbons. In this regard, oil and gas are irreplaceable resources.
• It is possible to obtain the proper amount of energy from nuclear power plants. The splitting of the atom is a promising industry, but a couple of disasters pushed this option into the background for a long time.
• Wind, sun and even water currents can provide electricity. With a proper approach to the issue and the construction of modern structures.

Some new and promising industries today almost never develop and humanity is forced to continue to burn coal, smoke the sky and receive crumbs of energy. This state of affairs is beneficial to large corporations that receive huge incomes from the sale of combustible fuels.

It is possible that in the coming decades the situation will change at least a little and promising projects, in terms of alternative options for generating energy, will be given the green light. So far, one can only hope for the prudence of large investors who will prefer saving from the energy crisis in the future to immediate benefits.

Where did coal come from?

Regarding the formation of coal, there is accepted scientific theory:

1. Somewhere around 300-400 million years ago, much more organic matter was growing on Earth. It's about plants, giant green plants.
2. Like all living things, plants died. Bacteria, at that stage, could not cope with the task of completely decomposing these giants.
3. In the absence of oxygen access, entire layers of compressed and rotting ferns were formed.
4. Over the passing millions of years, epochs have changed, other formations were layered on top, the original layer lay deeper and deeper.

There is an opinion that gradually all this substance was transformed into peat, which later turned into coal. Such transformations are taking place or may still be taking place, from a theoretical point of view. But only in the presence of already formed peat, there is no longer a sufficient number of plants for the formation of new layers on the Earth. Not that era, not those climatic conditions.

It is worth noting that volume has changed dramatically.. Losses during the transition from peat to coal alone are 90%, and it is still unknown what the initial volume of dead plants was.

Properties of hard coal

All coal properties can be divided into significant for nature and for humans:

But still, the main and most interesting for us is the fact that a sufficient amount of energy is released during the combustion of coal. Approximately 75% of what can be obtained by burning the same amount of oil.

Defenders of nature are concerned about a completely different property - the ability to release carbon dioxide when burned . Burn a kilogram of coal and get almost 3 kg of emissions carbon dioxide in atmosphere. The global volume of consumption is already estimated at billions of tons of minerals, so the numbers are not funny at all.

Coal mining

In some countries, coal mines have long been closed:

• Low profitability. Today it is much more profitable to pump and sell oil and gas. Less cost, less possible consequences.
• High risk of accidents. Mine disasters are not uncommon in modern world even if all precautions are taken.
• Almost complete development of existing reserves. If the country started mining as early as the century before last and all the time "fed" from one coal basin, one should not expect much from it in our time.
• Availability of an alternative. It's about not only about oil and gas, nuclear energy has also taken its niche. Solar panels, windmills are being introduced, hydroelectric power stations are operating. The process is slow but inevitable.

But someone is still forced to descend into the mine:

1. Mining occurs at a depth of up to 1 km, as a rule.
2. The cheapest way is to mine coal no deeper than 100 m, in which case it can be done using an open method.
3. Shifts of miners equipped with tools and respirators are constantly descending into the face.
4. The role of manual labor has decreased significantly, most of the work is done by mechanisms.
5. Despite this, miners are constantly at risk of being buried under rubble and buried in a makeshift common grave.
6. Constant exposure to dust causes problems with the respiratory tract. Pneumoconiosis officially recognized as an occupational disease.

To a certain degree such work is compensated by solid salaries and early retirement.

How did coal come about?

It took hundreds of millions of years to form coal.

Here is how the process of its formation on Earth went:

• Massively bred plants on the surface, due to favorable climatic conditions.
• Gradually they died, and microorganisms did not have time to completely process the remains.
• The organic mass formed a whole layer. In some areas, there was no access to oxygen, especially in swampy areas.
• Under anaerobic conditions, specific microorganisms continued to take part in the processes of putrefaction.
• New layers were layered on top, increasing the pressure.
• Thanks to the organic basis large quantity carbon, rotting, constant pressure and hundreds of millions of years coal was formed.

This is how scientists see the whole process, based on modern methods study.

Perhaps this picture will still be amended in the future, time will tell. In the meantime, we can only believe her or voice some of our assumptions. But to be taken seriously, they have to be proven.

It is not necessary to know how coal was formed in order to enjoy all the delights scientific and technological progress. But for general development it is worth reading.

Video about the appearance of coal on Earth

In this video, geologist Leonid Yaroshin will tell you how and where coal was formed, how it is mined and where it is currently used:

"How Coal Was Formed" short message presented in this article will help you prepare for the lesson and expand your knowledge on this topic.

The message "How coal was formed"

Coal is an irreplaceable, exhaustible, solid mineral used by humans to generate heat in the process of burning it. It belongs to sedimentary rocks.

What is needed to form coal?

First, a lot of time. When peat is formed from plants at the bottom of the swamps, then there are chemical compounds: plants decay, partially dissolve or turn into methane, carbon dioxide.

Secondly, all kinds of fungi and bacteria. Thanks to them, the decomposition of plant tissue occurs. Peat begins to accumulate a persistent substance called carbon, which becomes more and more over time.

Thirdly, the lack of oxygen. If it accumulated in peat, then coal could not form and simply evaporated.

How is coal formed in nature?

Coal deposits were formed from a huge amount of plant matter. Ideal conditions are when all these plants have accumulated in one place and have not had time to completely decompose. Swamps are the best suited for this process: the water is poor in oxygen and therefore the vital activity of bacteria is suspended.

After the plant mass has accumulated in the swamps, it, without having time to completely rot, is compressed by soil deposits. This is how the source material of coal, peat, is formed. Layers of soil seal it in the ground without access to oxygen and water. Over time, peat turns into a layer of coal. This process is long - a significant part of the coal reserves was formed more than 300 million years ago.

And the longer the coal lies in the layers of the earth, the stronger the fossil is exposed to the action and pressure of deep heat. In swamps where peat accumulates, sand, clay and dissolved substances enter with water, which are deposited in coal. These impurities give interlayers in the mineral, dividing it into layers. When coal is cleaned, only ash remains from them.

There are several types of coal - bituminous coal, brown coal, lignite, boghead, anthracite. Today there are 3.6 thousand coal basins in the world, which occupy 15% of the earth's land. The United States holds the largest percentage of the world's fossil reserves (23%), followed by Russia (13%) and China third (11%).

We hope that the report “How coal was formed” helped you prepare for the lesson. And you can add a message on the topic “How coal was formed”, you can use the comment form.

Its application is so multifunctional that sometimes you just wonder. At such moments, doubt involuntarily creeps in, and a completely logical question sounds in my head: “What? Is it all coal?!” Everyone is used to considering coal as just a combustible material, but, in fact, its range of applications is so wide that it seems simply incredible.

Formation and origin of coal seams

The appearance of coal on Earth dates back to a distant Paleozoic era when the planet was still in the development stage and had a completely alien look to us. The formation of coal seams began about 360,000,000 years ago. It happened mainly in bottom sediments prehistoric reservoirs where organic materials accumulated for millions of years.

Simply put, coal is the remains of the bodies of giant animals, tree trunks and other living organisms that have sunk to the bottom, decayed and pressed under the water column. The process of formation of deposits is quite long, and it takes at least 40,000,000 years for the formation of a coal seam.

Coal mining

People have long understood how important and indispensable, and the use of it was able to evaluate and adapt on such a scale relatively recently. Large-scale development of coal deposits began only in the XVI-XVII centuries. in England, and the extracted material was used mainly for the smelting of iron, necessary for the manufacture of cannons. But its production by today's standards was so insignificant that it cannot be called industrial.

Large-scale mining began only closer to mid-nineteenth in., when the developing industrialization became simply necessary for coal. Its use, however, at that time was limited exclusively to incineration. Hundreds of thousands of mines are now operating all over the world, producing more per day than in a few years in the 19th century.

Varieties of hard coal

Deposits of coal seams can reach a depth of several kilometers, extending into the thickness of the earth, but not always and not everywhere, because it is both in content and in appearance heterogeneous.

There are 3 main types of this fossil: anthracite, brown coal, and peat, which very remotely resembles coal.

Anthracite is the oldest formation of its kind on the planet, average age of this species is 280,000,000 years old. It is very hard, has a high density, and its carbon content is 96-98%.

The hardness and density are relatively low, as is the carbon content in it. It has an unstable, loose structure and is also oversaturated with water, the content of which in it can reach up to 20%.

Peat is also classified as a type of coal, but not yet formed, so it has nothing to do with coal.

Properties of hard coal

Now it is difficult to imagine another material more useful and practical than coal, the main properties and application of which deserve the highest praise. Thanks to the substances and compounds contained in it, it has become simply indispensable in all areas of modern life.

The coal component looks like this:

All these components make coal, the application and use of which is so multifunctional. Volatile substances contained in coal provide rapid ignition with the subsequent achievement of high temperatures. The moisture content simplifies the processing of coal, the calorie content makes its use indispensable in pharmaceuticals and cosmetology, the ash itself is a valuable mineral material.

The use of coal in the modern world

Various uses of minerals. Coal was originally only a source of heat, then energy (it turned water into steam), but now, in this regard, the possibilities of coal are simply unlimited.

Thermal energy from coal combustion is converted into electrical energy, coke-chemical products are made from it, and liquid fuel is extracted. Hard coal is the only rock that contains such rare metals as germanium and gallium as impurities. From it, it is extracted, which is then processed into benzene, from which coumarone resin is isolated, which is used to manufacture all kinds of paints, varnishes, linoleum and rubber. Phenols and pyridine bases are obtained from coal. During processing, coal is used in the production of vanadium, graphite, sulfur, molybdenum, zinc, lead, and many more valuable and now irreplaceable products.

Wood has long been used to heat houses, but in order to constantly keep burning, it is necessary to put logs on again and again. With the development of the coal mining industry, all more people began to use coal: it gives more heat, burns longer. With the correct laying of the furnace, a portion of coal, poured into the boiler in the evening, will maintain a stable temperature all night.

The history of the formation of coal and its types

The whole process of coal formation can be divided into two main stages: the formation of peat and the process of coalification itself - the transformation of peat into coal.

Peat was formed on vast expanses covered with water from plant residues of varying degrees of decomposition. Some of the plants rotted completely to a gel-like state, some retained their cellular structure. Their remains accumulated at the bottom of reservoirs, which gradually turned into swamps. Required condition necessary for the formation of peat - the absence of oxygen. There was little oxygen under the water column; during the decomposition of the remains, hydrogen sulfide, methane and carbon dioxide were released, which contributed to the hardening of the remains. Peat was formed.

But not all peatlands were converted to coal. The coalification process requires: high pressure, high temperature and a long period of time. Depending on the presence of these conditions, the formation of coal took place or not. First, the peat was brought in by sedimentary rocks, which increased the pressure and raised the temperature inside the peat layer. Under such conditions, brown coal was formed - the first stage of coalification. Seams have been shifted in some areas, causing brown coal seams to subside (some of the discovered deposits are at depths of more than 6,000 meters). In places, these processes were accompanied by the rise of magma and volcanic eruptions. High pressure, lack of oxygen and high temperatures contributed to the fact that moisture and natural gases in brown coal became less and less carbon, more and more. With the displacement of water and gases, brown coal turned into bituminous, then, in the presence of high temperature, into anthracite. The main difference between brown coal and hard coal is that brown coal contains more moisture and natural gases and less carbon, which affects the amount of heat released during combustion.

Today, the age of coal deposits is determined by plant remains. The most ancient date back to the Carboniferous period (345-280 million years ago). During this period, most of the coal basins were formed. North America(east and center of the USA), center and west of Europe, southern Africa, China, India. In Eurasia, most of the coal deposits were formed in the Permian period, some of the small coal basins in Europe date back to the Triassic period. The activity of carbon formation increases towards the end Jurassic and in Melovoye. Around this time, deposits were formed in the east of Europe, in the Rocky Mountains of America, in Indochina and the center of Asia. Later, mainly brown coals and peat deposits were formed.

Types of coal

Coal is classified according to its moisture content, natural gases and carbon content. With an increase in the amount of carbon, its calorific value increases. The less moisture and volatile substances (gases), the better it tolerates storage and transportation.

Lignite- coal of the first stage of coalification. It differs from brown coal in a smaller amount of water (45%) in the composition and in a large release of heat. The structure is fibrous, the color is from brown to black (higher quality). Most often used in the energy sector (at thermal power plants) for heating private houses it is rarely used, as it is poorly stored and has a low calorific value in conventional furnaces.

Subbitominous coal- black color, less pronounced fibrous structure, higher calorific value compared to lignite, lower moisture content (30%). It crumbles during transportation, and weathers in the open air. When burned, it releases 5-6 kW / kg. It is used both in power engineering and in housing and communal services for heating.

bituminous coal has the highest calorific value, does not lose its qualities during transportation and storage. It emits 7-9 kW / kg of heat during combustion. Some of its species are used for coking.

Anthracite- jet black charcoal. It has the highest hydrocarbon content. It is difficult to ignite it, but it burns for a long time and without soot, it releases a large amount of heat (more than 9 kW / kg). It is anthracite that is most often used for heating.

What kind of coal is used for heating

In Russia and the CIS countries, there is a system adopted back in 1988. Coal is classified according to GOST 25543-88, which is divided into 7 categories. Only a few are used for heating:

Long-flame coal (D). It got its name due to the long combustion process with the release a large number heat (5600-5800 kcal/kg). For its ignition and combustion, special blowing is not required, therefore long-flame coals are often used in domestic solid fuel boilers. Depending on the size, it happens:

• WPC - large slab - the size of the pieces is 50-200 mm;
• DPKO - slab fist-nut - sizes of pieces 25-100 mm;
• PO - walnut - 26-50 mm;
• DM - small - sizes 13-25 mm;
• DS - seed - 6-13 mm;
• DR - private - no standard sizes.

Long-flame coal is optimal for heating: the flame is long (similar to “give out” firewood), a lot of heat is released, it ignites and burns easily - natural draft is enough for normal combustion. Its relatively low cost, combined with excellent characteristics, determined the popularity of this brand of coal. It is purchased not only for heating private houses, but also for boiler rooms of educational and medical institutions. Moreover, fuel of any fraction is used: from large "K" to small "M".

Long-flame gas (DG). Differs from grade D in greater calorific value. All fractions are used for heating private houses: from “large” to “ordinary”. More demanding than long-flame to storage conditions, tk. more intensively weathered.

Anthracite (A). It emits a lot of body, has a low ash content (ash residue 10%), burns for a long time and evenly, the smoke during combustion is white (all other brands “give” black smoke). Despite the high performance, it is impossible to unequivocally recommend it for heating private houses: anthracite has a high cost and is difficult to kindle.

In some cases, they buy lean coals "T", fat "G" or slightly caking "SS". The rest of the classes have predominantly industrial uses. They are used in energy and metallurgy, some grades for coking and enrichment. When choosing coal, you need to pay attention not only to its characteristics, but also to the cost of delivery. If your area does not sell long flame or anthracite, then most likely you will have to make do with what is on the market. You also need to pay attention to the recommendations of the manufacturers of your boiler: the documents usually indicate the brands for which the equipment was designed. They must be used.

To increase comfort and in order to save money, many people prefer to have several fractions: it is more convenient to melt with the “nut” or “large” fraction, and pour the “seed” for a long burning. For the coldest periods, a certain amount of anthracite is stored, which, although it is difficult to kindle, burns long and hot in a heated boiler.

Coking and enriched coals undergo special treatment to increase their calorific value. These species are used in metallurgy and energy. Such fuel is not suitable for domestic boilers: due to the excessively high combustion temperature, the furnace can break.

If you listen to people with experience, they say that the best effect is given by the following sequence of pouring fuel into the boiler: melt with a long flame, then fill in anthracite of the “nut” fraction - it burns for a long time, you give a lot of heat, and at night add “seeds” to the stove, which will burn until morning.

The order of kindling brick ovens is recommended differently: they kindle the oven with wood, when it flares up well, fall asleep with “seed” or (open the blower and damper for a better supply of oxygen). If there is a lot of dust in the seed, it can be moistened with water - this way it flares up more easily. When the heat in the oven is sufficient, the "fist" can be used.

What is charcoal and what is it used for

Charcoal has been used by people for many thousands of years: it was found during excavations in the settlements of cavemen. It is unlikely that they made it themselves, rather they collected it on fires or preserved the remains of fires, but, apparently, they knew about its properties and knew how to use it.

Today, in our country, this type of fuel is mainly used for cooking: it is used in barbecues and barbecues, put in fires. Sometimes they are used for fireplaces: it burns for a long time, emits a lot of heat (7800 KC / kg), and there is almost no smoke and soot. The remaining ash is an excellent fertilizer and is used to fertilize forest land or agricultural fields. Charcoal ash is also used for the production of fertilizers.

In industry, charcoal is used for iron smelting. It takes only 0.5 tons of this fuel to produce a ton of alloy. At the same time, cast iron receives increased resistance to corrosion and strength. As a flux, coal is used in the smelting of brass, bronze, copper, manganese, zinc and nickel. It is used to make a solid lubricant for mechanical engineering, is used for grinding in instrument making and printing, etc. Filters for various purposes are made from charcoal.

Today, charcoal is beginning to be seen as an alternative to traditional fuels: unlike coal, oil and gas, it is a renewable material. And modern technologies make it possible to obtain charcoal even from industrial waste: from sawdust, dust, shrubs, etc. Briquettes are formed from such crushed raw materials, which give 1.5 times more heat than ordinary charcoal. In this case, heat is released for a longer period of time and the heat is uniform.

How is charcoal made

Until the 20th century, charcoal was obtained by burning wood or specially shaped piles. Wood was laid in them, covered with earth, set on fire through special holes made. This technology is publicly available and is still used in some countries. But it has low efficiency: up to 12 kg of wood is consumed per 1 kg of coal, and it is also impossible to control the quality of the resulting charcoal. The next stage in the development of charcoal burning was the use of pipes in earth furnaces. This improvement increased the efficiency of the process: 8 kg of timber was consumed per kilogram.

In modern charcoal burners, 3-4 kg of raw materials are consumed per kilogram of product. At the same time, great attention is paid to the environmental friendliness of the process: during the production of charcoal, a lot of smoke, soot and harmful gases. Modern installations capture the emitted gases, send them to special chambers, where it is used to heat the furnace to the coking temperature.

The transformation of wood into charcoal takes place in an oxygen-free atmosphere at high temperature(pyrolysis reaction). The whole process is divided into three stages:

• at 150 ° C, moisture is removed from the wood;
• at 150-350 about With the release of gases and the formation of organic products;
• at 350-550 ° C, resins and non-condensable gases are separated.

According to GOST, charcoal is divided into several grades depending on the type of wood used:

• • A - hardwood species;
  • B - hard and soft hardwood, coniferous species (o).

Grades B and C - most often these are charcoal briquettes, for the manufacture of which waste from wood processing enterprises is used. This is an excellent type of biofuel that has long been used in Europe for heating and even in power plants: when they are burned, sulfur compounds are not formed (there is no sulfur in charcoal), and the hydrocarbon is contained in minimum quantities. Using the technology of ancestors, you can burn coal for your own needs yourself. .