Xylenes are produced, along with benzene and toluene, from a reformer after running naphtha through an ethylene cracker. Their major use is in the production ofpara- and ortho-xylene which are split when xylenes are run through an isomerisation unit. They are also used as a solvent in the paints industry and for other solvent uses.
Paraxylene (PX) is the largest volume isomer of the mixed xylenes. Around 98% of PX demand comes from the polyester chain via the one of its intermediates purified terephthalic acid (PTA) or dimethyl terephthalate (DMT). Most xylenes production ends up in the polyester chain via paraxylene.
Mixed xylenes occur as a colourless, flammable liquid or crystals, with a characteristic odour. They are insoluble in water and miscible with most organic solvents.
Mixed xylenes is a clear, sweet and flammable aromatic liquid or vapour. It is harmful or fatal if swallowed or inhaled, causing respiratory tract irritation, eye and skin irritation or an allergic skin reaction.
To find out more Xylenes Methodology September 2013