WORKING-UP PITCH, ASPHALT, BITUMEN, TAR

**Definition:** This place covers:

Working-up, e.g.processing, of tar, pitch, asphalt or bitumen, including use of techniques such as distillation, heat-treatment, water removal or extraction with selective solvents.

Working up implies improvement of the material.

Production of pyroligneous acid.

**Limiting references (this place does not cover):** - Working up pyroligneous acid for production of acetic acid -> ( C07C51/42 , C07C53/08 ) - Carbonisation of wood -> C10B53/02 - Obtaining hydrocarbon oils -> C10G - Deasphalting hydrocarbon oils -> C10G21/00 - Dewatering of hydrocarbon oils -> C10G33/00

**Glossary:** - Tar: Tar is a black thermoplastic material produced by the destructive distillation of coal – sometimes referred to as coal tar. Is also a residue in the manufacture of coal gas and coke. May also be derived from plants such as pine trees. - Pitch: Pitch is the name of a large number of highly viscous liquids which appear solid. Pitch may be made from petroleum or plant sources. Petroleum derived pitch is also known as bitumen whereas plant derived pitch is known as resin. Pitch derived from plant resin however is known as rosin.Tar and pitch are often used interchangeably. However, pitch is considered to be more solid whilst tar is considered to be more liquid. - Asphalt: Asphalt is a sticky, black and highly viscous liquid or semi solid that is present in crude petroleum and in some natural deposits sometimes termed asphaltum. In US terminology asphalt (or asphalt cement) is the carefully refined residue from the distillation process of selected crude oils. Outside of the US, the product is called bitumen. - Bitumen: Bitumen is a mixture of organic liquids that are highly viscous, black, sticky, entirely soluble in carbon disulfide and composed primarily of highly condensed polycyclic aromatic hydrocarbons. - Pyroligneous acid: Pyroligneous acid, also called wood vinegar, is a dark liquid produced by the destructive distillation of wood. Its principal components are acetic acid and methanol. It was once used as a commercial source for acetic acid.