Coal Gas
Explanation
The process involved is the destructive distillation of coal, which entails heating coal strongly in the absence of air. This industrial process is primarily used to produce coke, a crucial reducing agent in metallurgy.
- Coal Gas: This is a gaseous fuel obtained as a byproduct during the processing of coal to get coke. It is a mixture of hydrogen, methane, and carbon monoxide and has a high calorific value. Historically, it was used for street lighting but is now used as a source of heat.
- Natural Gas: This is a naturally occurring hydrocarbon gas mixture consisting primarily of methane. It is found in underground rock formations, often alongside petroleum, and is not a byproduct of coal processing.
- Biogas: This is produced through the anaerobic decomposition of organic matter (such as agricultural waste, manure, or sewage) by bacteria. It is not derived from coal.
- Petroleum Gas: This is obtained during the fractional distillation of crude oil (petroleum). It is commonly stored as Liquefied Petroleum Gas (LPG).
Key Takeaway: The destructive distillation of coal yields coke as the solid residue, while coal tar, coal gas, and ammoniacal liquor are obtained as byproducts.