Biogas
Explanation
The processing of coal in industry, specifically through a method known as destructive distillation (heating coal strongly in the absence of air), yields several useful by-products. Biogas, in contrast, is derived from biological processes involving organic waste.Analysis of Options:
- Coke: This is a tough, porous, and black substance obtained as a residue during the destructive distillation of coal. It is an almost pure form of carbon and is essential in the manufacture of steel and the extraction of many metals. Therefore, it is a product of coal.
- Coal Tar Coal Tar: This is a black, thick liquid with an unpleasant smell obtained during coal processing. It is a mixture of various substances and serves as a starting material for manufacturing synthetic dyes, drugs, explosives, perfumes, plastics, and roofing materials. Therefore, it is a product of coal.
- Coal Gas Coal Gas: This gaseous fuel is obtained during the processing of coal to get coke. It is used as a source of heat in many industries located near coal processing plants. Therefore, it is a product of coal.
- Biogas: This is not a product of coal processing. Biogas is produced through the anaerobic decomposition of organic matter (such as animal dung and plant waste) by bacteria. It is a renewable fuel source primarily composed of methane.
Key Takeaway: Coke, coal tar, and coal gas are derivatives of fossil fuel (coal) obtained via destructive distillation, whereas biogas is a product of the biological breakdown of biomass.