How Did Gas Works Work?

Gas works primarily produced gas, historically known as town gas, by heating coal in specialized structures.

The Core Process of Coal Gas Production

The fundamental operation of a gas works involved heating coal in the absence of air to produce a flammable gas. This process is called carbonization or destructive distillation of coal.

Here's a breakdown of the key steps and components based on historical gas works:

• Heating the Coal: The process began in structures containing retorts. These were essentially ovens or chambers made of heat-resistant materials where coal was loaded.
• Generating the Gas: In the retorts, coal was intensely heated. This heating process released volatile components from the coal in the form of gas. The provided reference states: "This contained the retorts in which coal was heated to generate the gas."
• Siphoning Off Crude Gas: The gas generated was not immediately ready for distribution. It was a 'crude' gas, meaning it contained various impurities. The reference notes: "The crude gas was siphoned off and passed on to the condenser." This crude gas would then undergo further purification stages (not detailed in the reference but standard in gas works) to remove tar, ammonia, sulphur compounds, and other by-products.
• Condensation: The crude gas, carrying hot vapors, was then cooled in a condenser. This cooling process caused some of the impurities, such as tar and ammoniacal liquor, to condense into liquids, which could then be separated.
• By-Product: Coke: After the volatile gases were driven off from the coal in the retorts, a solid residue remained. This was coke. The reference explicitly states: "The waste product left in the retort was coke." Coke is a useful fuel itself.
• Utilizing the Coke: The coke produced as a by-product was often put to use. According to the reference: "In many cases the coke was then burned to heat the retorts or sold as smokeless fuel." This shows an efficient cycle where a waste product helped fuel the main process or was a valuable commodity.

This initial process of heating coal to produce crude gas and coke was the foundational step in a gas works, followed by extensive purification and storage before the gas was distributed.