A feedstock is a petrochemical used as a raw material to be fed into a machine or processing plant. Examples of feedstock petrochemicals are ethylene, propylene, butadiene, benzene, toluene, xylene, and naphthalene. A petrochemical is any chemical derived from fossil fuel. ... A machine is any mechanical or organic device that transmits or modifies energy to perform or assist in the performance of tasks. ... Ethylene or ethene is the simplest alkene hydrocarbon, consisting of two carbon atoms and four hydrogens. ... Propylene, also known by its IUPAC name propene, is an organic compound having the chemical formula C3H6. ... Butadiene can refer to either one of two hydrocarbon chemical compounds which are alkenes that are isomers of each other. ... Benzene, C6H6, PhH, or benzol is a colorless and flammable liquid with a pleasant, sweet smell. ... Toluene, also known as methylbenzene or phenylmethane is a clear water-insoluble liquid with the typical smell of paint thinners, reminiscent of the sweet smell of the related compound benzene. ... The term xylenes refers to a group of 3 benzene derivatives which encompasses ortho-, meta-, and para- isomers of dimethyl benzene. ... Naphthalene (also known as naphthalin, naphthaline, tar camphor, white tar, albocarbon, or naphthene) is a crystalline white solid hydrocarbon with a typical mothball odor. ...