What is the process of coal called dry distillation of coal??

The dry distillation of coal refers to the process of isolating coal from air and strengthening heat to decompose it, which is also called coking of coal in industry, which is a chemical change. Important chemical raw materials can be obtained from coal distillates.

The process of isolating coal from air and strengthening heat to decompose it is called dry distillation of coal, also known as coking of coal.

The process of isolating the air to enhance heat is called dry distillation.

One of the important processes of coal chemical industry. It refers to the process of heating and decomposing coal under the condition of isolated air to produce coke (or semi-coke), coal tar, crude benzene, coal gas and other products. According to the different heating final temperature, it can be divided into three types:

900 1100 is high-temperature dry distillation, that is, coking; 700 900 for medium temperature dry distillation; 500 600 is low-temperature dry distillation (see Coal Low Temperature Distillation).

The dry distillation process of coal mainly undergoes the following changes: when the temperature of the coal is higher than 100, the water in the coal evaporates; When the temperature rises above 200, the coal is released with water; When it reaches more than 350, the cohesive coal begins to soften and further forms a viscous colloidal body (peat, lignite, etc. do not occur); to 400 500 Most of the gas and tar precipitation, called the primary thermal decomposition products; At 450 550, thermal decomposition continues, the residue gradually thickens and solidifies to form semi-coke; Above 550, the semi-coke continues to decompose, precipitating the remaining volatiles (the main component is hydrogen), and the semi-coke weight loss shrinks at the same time to form cracks; At temperatures above 800, the semi-coke shrinks and hardens to form porous coke. When the dry distillation is carried out in the chamber retort furnace, the primary thermal decomposition products come into contact with the red hot coke and the high-temperature furnace wall, and the secondary thermal decomposition products (coke oven gas and other coking chemical products) are formed.

The products of coal dry distillation are coal, coal tar, and coal gas.

The yield and composition of the coal distillation product depends on the quality of the raw coal, the furnace structure and the processing conditions (mainly temperature and time). With the difference in the final temperature of the dry distillation, the dry distillation products of coal are also different. The solid product of low-temperature dry distillation is black semi-coke with loose structure, low gas yield and high tar yield. The solid product of high-temperature dry distillation is silver-gray coke with dense structure, with high gas yield and low tar yield.

The yield of medium-temperature distillation products is between low-temperature distillation and high-temperature distillation. The main components of coal gas produced in the dry distillation process are hydrogen and methane, which can be used as fuel or chemical raw materials. High-temperature dry distillation is mainly used for the production of metallurgical coke, and the resulting tar is a mixture of aromatic hydrocarbons and heterocyclic compounds, which is an important factor in the industrial production of aromatic hydrocarbons; Low-temperature dry distillation coal tar contains more alkanes than high-temperature tar, which is one of the important artificial oils.

The main products of coal dry distillation are coke, coal, tar and coal gas. The yield and composition of coal dry distillation products depend on the structure of the raw coal furnace and the processing conditions, mainly temperature and time, with the different final temperature of the dry distillation, the dry coal products are also different, the low temperature dry distillation solid products are loose black semi-coke gas, the yield is low, the tar yield is high.

Characteristics of the main products of coal dry distillationBurning coal is an important energy resource for human beings, any coal can be used as industrial and civil fuel, coking puts coal in a dry retort furnace, isolated from air heating, the organic matter in the coal is gradually decomposed with the increase in temperature, and the volatile substances escape in a gaseous or vapor state to become coke oven gas and coal tar, and the non-volatile solid residue is coke.

Coke oven gas is a kind of fuel is also an important chemical raw material, coal tar can be used to produce chemical fertilizers, pesticides, synthetic fibers, synthetic rubber, paints, dyes, pharmaceutical explosives, etc., coke is mainly used in blast furnace ironmaking and casting, and can also be used to manufacture nitrogen fertilizer calcium carbide, calcium carbide is a synthetic chemical product such as plastic synthetic fiber, synthetic rubber, etc.

1. The dry distillation products of coal mainly include: search fingers.

1) Furnace gas (including coke oven gas.

Crude ammonia. crude benzene).

2) Coal tar.

3) Coke (bitumen, carbon).

2. The use of coal dry distillation products:

1) Coke oven gas is used for gaseous fuels, chemical raw materials.

2) Crude ammonia is used for nitrogen fertilizer.

3) Crude benzene is used in explosives, dyes.

Medicine, medicine, synthetic materials.

4) Coal tar is used in explosives, dyes, medicines, pesticides, synthetic materials.

5) Coke is used for electrodes, road construction materials, metallurgy, fuels, and ammonia.

Coke gas, coal tar, coke. Coal is heated and decomposed under the condition of isolated air to produce coke (or semi-coke), coal tar, crude benzene, coal gas and other products, and the dry distillation of coal is a chemical change. <

Coal dry distillation. Get coking gas, coal tar, coke. Coal is heated and decomposed under the condition of isolated air to produce coke (or semi-coke), coal tar, crude benzene, coal gas and other products, and the dry distillation of coal is a chemical change.

Main uses of coal Coal is an important energy source and an important raw material for metallurgical and chemical industries. It is mainly used for combustion, coking, gasification, low-temperature dry distillation, hydrogenation liquefaction, etc.

1. Combustion: Coal is an important energy resource for human beings.

It can be used as an industrial and civil fuel.

2. Hidden coking: the coal is placed in a dry distillation furnace to isolate the air for heating, and the organic matter in the coal is gradually decomposed with the increase of temperature, and the volatile substances escape in a gaseous or vapor state to become coke oven gas.

and coal tar, and non-volatile solids residues are coke. Coke oven gas is a fuel and an important raw material for chemical production. Coal tar can be used to produce fertilizers, pesticides, synthetic fibers, synthetic rubber, paints, dyes.

Medicine, explosives, etc.

Coke is mainly used in blast furnace ironmaking.

and casting, which can also be used to make nitrogen fertilizer and calcium carbide.

Calcium carbide is a synthetic chemical product such as plastics, synthetic fibers, and synthetic rubber.

3. Gasification: Gasification refers to the conversion of gas into coal gas that can be used as industrial or civil fuel and chemical synthesis raw material.

4. Low temperature dry distillation: put coal or oil shale.

Placed at a temperature of about 550 degrees Celsius, low-temperature dry distillation can produce low-temperature tar and low-temperature coke oven gas, which can be used to make high-grade liquid fuels and as chemical raw materials.

5. Hydroliquefaction: coal, catalyst and heavy oil are mixed together, the organic matter in the coal is destroyed at high temperature and high pressure, and the reaction with hydrogen is converted into low-molecular liquid and gaseous products, and liquid fuels such as gasoline and diesel are further processed. The raw coal for hydroliquefaction is mainly lignite, long-flame coal and gas coal.

Dry distillation of coal is a chemical change that is the process of decomposing coal by increasing heat in isolation from air. It is also called coking in industry, and there are two main types of ingredients: furnace gas and coke. There are many components of baking gas.

Because there is the breaking of the old bond and the formation of a new bond. But the process must be accompanied by physical changes. The principle is the decomposition of coal at high temperatures, which is completely different from the principle of petroleum fractionation.

The process of isolating coal from air and strengthening heat to decompose it is called dry distillation of coal, also known as coking of coal. When coal isolates the air from strong heat, gas is generated, and its composition is coal tar, coke oven gas, crude ammonia, and coarse stupidity.

The black solid material after the reaction is called coke. They are all very important chemical raw materials. Therefore, dry distillation of coal can give full play to the use value of coal to a greater extent. It saves energy and protects the environment, so it is very important to actively carry out the comprehensive utilization of coal.

The dry distillation of coal is a chemical change.

Data Extension:

Coal is mainly composed of carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus and other elements, and the sum of carbon, hydrogen and oxygen accounts for more than 95% of organic matter, which is a very important energy source, and is also an important raw material for metallurgy and chemical industry. The famous writer Zhu Ziqing also wrote a poem titled coal, giving it a unique symbolic meaning.

As of 2011, China is the world's largest coal producer, with a coal output of 100 million tons, equivalent to 100 million tons of oil equivalent, accounting for a high proportion of the worldThis is followed by the United States, which accounts for a percentage of world production

In third place is Australia, which accounts for a percentage of the world's hunger industryIndia and Indonesia ranked fourth and fifth, respectively, accounting for a share of world production.

Coal is a non-renewable resource. Coal is a solid combustible mineral that ancient plants buried in the ground and underwent complex biochemical and physicochemical changes gradually or bent to form a solid combustible organic rock, which is mainly formed by the biochemical action of plant dust and the remains of the body after burial. Commonly known as coal.

China was the first country in the world to use coal.

In the Xinle ancient cultural sites in Liaoning Province, coal handicrafts were found, and Gongyi City, Henan Province also found the ruins of using briquettes to make iron in the Western Han Dynasty. In the "Classic of Mountains and Seas", coal is called Shini, and in the Wei and Jin dynasties, coal is called graphite or carbon. Li Shizhen's "Compendium of Materia Medica" in the Ming Dynasty used the name coal for the first time.

Greece and ancient Rome were also early coal users, and the Greek scholar Theophrastus wrote the History of Stone around 300 BC. It records the nature and origin of the coal;Ancient Rome began heating with coal about 2,000 years ago. Coal is a mineral that can be used as a fuel or as an industrial feedstock.

It is a black solid mineral composed of carbon, hydrogen, oxygen, nitrogen and other elements that have changed their physical and chemical properties through biochemical and geological processes in ancient plants. Coal is also a source of organic compounds. Various aromatic hydrocarbons can be obtained by the fractionation of coal tar;Through the direct or indirect liquefaction of coal, fuel oil and a variety of chemical raw materials can be obtained.

The dry distillation of coal is a process of chemical change.

The dry distillation of coal is mainly divided into three stages: dehydration, pyrolysis, and coking.

1. Dehydration stage: In this stage, the coal is in contact with water vapor, the water is evaporated, the trace of fixed carbon in the coal is reduced, and a small amount of hydrogen, methane and other gases are released. The main purpose of this stage is to reduce the moisture content of the coal and make it suitable for subsequent pyrolysis and coking processes.

2. Pyrolysis stage: In this stage, the coal reacts with oxygen at high temperature to generate organic substances of various slow species. These organic substances include liquid fuels, gaseous fuels, and by-products such as solid carbon black and slag.

In the pyrolysis process, the main components in coal are carbon, hydrogen, oxygen, nitrogen and other elements, which undergo chemical reactions under high temperature conditions to form various organic compounds.

3. Coking stage: In this stage, the organic matter in the coal is further decomposed at high temperature to produce coke, coal tar, crude ammonia and other products. The coking process is a fractional distillation process, by controlling the temperature and pressure, the organic substances in the coal can be separated to obtain coke products of different qualities and properties.

The dry distillate products of coal include coke, coal gas, coal tar, and crude ammonia

1. Coke: Coke is a solid fuel produced in the process of coal dry distillation, which has high calorific value and good chemical stability. It is widely used in metallurgy, chemical industry, construction and other industries as a reducing agent and energy**.

2. Coal gas: Coal gas is one of the gas products produced in the process of coal dry distillation. Coal gas is mainly composed of methane and small amounts of ethane, propane, butane, etc. The combustion of coal gas can produce a large amount of heat, so it plays an important role in urban heating and industrial production.

3. Coal tar: It is one of the liquid products produced in the process of coal dry distillation. Coal tar contains a variety of organic compounds, such as benzene, toluene, xylene, etc.

These compounds are toxic and carcinogenic, so they need to be treated and utilized. Coal tar is widely used in the chemical industry as a building block for solvents, fuels and lubricants.

4. Crude ammonia: It is one of the inorganic products produced in the process of coal dry distillation. Crude ammonia is mainly composed of ammonia and water, which is alkaline and corrosive. It can be used in the preparation of chemicals such as fertilizers, fertilizers, and synthetic amino acids.

The dry distillation of coal refers to the process of heating and decomposing coal under the condition of isolated air to produce coke (or semi-coke), coal tar, crude benzene, coal gas and other products, so the dry distillation of coal is a chemical change. Dry distillation is a complex chemical reaction process, including dehydration, pyrolysis, dehydrogenation, thermal condensation, hydrogenation, coking, and other reactions. The dry distillation of coal can generally be divided into three stages:

1. Dehydration and decomposition: At the beginning of the dry distillation operation, the temperature is relatively low, and the organic matter is dehydrated first, and as the temperature increases, it gradually decomposes to produce low molecular volatiles.

2. Pyrolysis: As the distillation temperature continues to rise, the macromolecules in the organic matter will be broken by bonds, that is, pyrolysis will occur to obtain liquid organic matter (including tar). These distillate products vary depending on the distillate material, such as furfural from chaff husks, shale oil and some heterocyclic compounds from distillate shale.

3. Condensation and carbonization: When the temperature is further increased, with the precipitation of water and organic vapor, the remaining substances are condensed into colloids by heat. At the same time, precipitate.

The volatiles are gradually reduced, and the colloids are gradually solidified and carbonized. As the temperature increases and the heating time increases, the carbon content of the solid products produced gradually increases, and the content of other elements such as hydrogen, oxygen, nitrogen and sulfur gradually decreases.