Propylene in the context of "Liquified petroleum gas"

Petrochemicals (sometimes abbreviated as petchems) are the chemical products obtained from petroleum by refining. Some chemical compounds made from petroleum are also obtained from other fossil fuels, such as coal or natural gas, or renewable sources such as maize, palm fruit or sugar cane.

The two most common petrochemical classes are olefins (including ethylene and propylene) and aromatics (including benzene, toluene and xylene isomers).

Distillation, also classical distillation, is the process of separating the component substances of a liquid mixture of two or more chemically discrete substances; the separation process is realized by way of the selective boiling of the mixture and the condensation of the vapors in a still.

Distillation can operate over a wide range of pressures from 0.14 bar (e.g., ethylbenzene/styrene) to nearly 21 bar (e.g.,propylene/propane) and is capable of separating feeds with high volumetric flowrates and various components that cover a range of relative volatilities from only 1.17 (o-xylene/m-xylene) to 81.2 (water/ethylene glycol). Distillation provides a convenient and time-tested solution to separate a diversity of chemicals in a continuous manner with high purity. However, distillation has an enormous environmental footprint, resulting in the consumption of approximately 25% of all industrial energy use. The key issue is that distillation operates based on phase changes, and this separation mechanism requires vast energy inputs.

John Williams Reynolds (25 December 1816 – 28 July 1874) was an English cavalry officer and organic chemist. His disagreement in 1840 with Lord Cardigan, his commanding officer, (the notorious "black bottle affair") made him famous, and a popular cause célèbre in London. At the end of 1840, he left his regiment to study at the Royal Military College, Sandhurst. After graduating, he did not return to regimental duties but took up the study of organic chemistry at the Royal College of Chemistry, London. He discovered the compound propylene, thus advancing the theory of homology. He was recalled to service in 1851 and rose to the rank of Major-General.