Coal gas, gaseous mixture—mainly hydrogen, methane, and carbon monoxide—formed by the destructive distillation (i.e., heating in the absence of air) of bituminous coal and used as a fuel. ... Coal tar and coke (qq.v.) are obtained as by-products.

Coal tar,coke,coal gas are the substances obtained during the process of conversion of coal into natural gas.coal tar is the liquid substance.coke is th a solid substance and coal gas is the gaseous substance.

Coal Tar:

Coal tar is a dark, thick, and sticky liquid that is obtained during the process of coal gasification or coal carbonization. It is a byproduct of the production of coke or coal gas. Coal tar is composed of various organic compounds, primarily aromatic hydrocarbons, and is known for its strong odor.

Composition and Uses:

Coal tar is a complex mixture of hundreds of organic compounds, including polycyclic aromatic hydrocarbons (PAHs), phenols, and heterocyclic compounds. It contains high levels of carbon and is rich in hydrocarbons, making it a valuable source of chemicals and materials. Some of the common components found in coal tar include benzene, toluene, naphthalene, anthracene, and phenol.

Coal tar has several applications:

1. Medicinal Uses: Coal tar is used in the production of various medications, such as creams, ointments, and shampoos, to treat skin conditions like psoriasis, eczema, and dandruff. Its anti-inflammatory and antifungal properties make it effective in managing these conditions.

2. Pavement and Roofing Materials: Coal tar is used as a binder in the production of asphalt and bitumen. It provides durability, water resistance, and UV protection to pavements, roads, and roofing materials.

3. Wood Preservation: Coal tar is used as a wood preservative to protect timber from decay, insect attack, and fungal growth. It is commonly used in the construction industry for treating utility poles, railway sleepers, and outdoor wooden structures.

4. Chemical Production: Coal tar is a valuable source of chemicals and intermediates used in the production of dyes, pigments, explosives, synthetic fibers, and pharmaceuticals. It serves as a feedstock for the synthesis of various organic compounds.

Coke:

Coke is a solid carbonaceous material that is derived from coal through a process called carbonization. It is made by heating coal in the absence of air or oxygen at high temperatures, causing the volatile components to evaporate and leaving behind a porous, carbon-rich substance.

Production and Applications:

The production of coke involves the following steps:

1. Coal Selection: The type and quality of coal used for coke production play a crucial role. Bituminous coal with low ash and sulfur content is commonly used.

2. Carbonization: The selected coal is heated in ovens or coke chambers at temperatures ranging from 900 to 1200 degrees Celsius. This process, known as carbonization, removes impurities and converts coal into coke.

3. Cooling and Solidification: After carbonization, the coke is cooled and solidified. It is then crushed into various sizes for different applications.

Coke has several applications:

1. Metallurgical Coke: Metallurgical coke is widely used in the iron and steel industry as a fuel and reducing agent in blast furnaces. It provides the necessary heat and carbon for the extraction of iron from iron ore.

2. Foundry Coke: Foundry coke is used in foundries for melting metals and casting. It provides a source of heat and carbon during the melting process.

3. Fuel Coke: Coke can be utilized as a fuel in industrial processes, such as cement kilns and power plants. It has a high calorific value and burns efficiently.

Coal Gas:

Coal gas,