Coal tar distillation

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Distillation columns from Rütgers Chemicals in Castrop-Rauxel

As a coal tar distillation is referred to the separation of the coal tar into useful ingredients in a Steinkohlenteerraffinerie . It developed partly before and partly parallel to petroleum distillation .

Procedure

The separation takes place by fractional distillation (partly also by vacuum distillation ). This creates different fractions, with subsequent rectification , crystallization and extraction , the different substances can be obtained.

There are different types:

Discontinuous distillation :

Gases (distillation loss ), water , light oil , medium oil , heavy oil , anthracene oil (green oil), pitch (pitch) asphalt C 2n H n (soluble components of the pitch), pitchcoke carbon C 3n H n (insoluble components of the pitch)

subsequently the medium and heavy fraction are further distilled and then one obtains: carbolic oil ( phenols ), washing oil (solvay oil), naphthalene oil ( naphthalene ) and also pitch .

Continuous distillation :

Gases, water, light oil, carbolic oil, naphthalene oil, washing oil, anthracene oil, pitch

Products

The main products of coal tar distillation are creosote and tar pitch . Creosote used to be used to impregnate railway sleepers, while tar was originally used primarily in road construction.

Anthracene oil consists mainly of phenanthrene , anthracene , carbazole and other high-boiling compounds such as 2,3,6,7-tetramethylnaphthalene, 1,2,3,4-tetrahydroanthracene, 1,8-dimethyldiphenylene oxide among the neutral and 7,8-benzoquinoline and 9 , 10-dihydroacrideine among the basic components.

Today, pitch is the most important economic product. It is used as binder for Soderberg electrodes in the production of aluminum and for the production of carbon black ( Carbon Black used).

Individual evidence

  1. ↑ Dieter Osteroth: From coal to biomass: chemical raw materials and energy sources in the course of time. Springer Verlag, 1989, ISBN 978-3-642-88669-0 , pp. 79-83.
  2. ^ Marshall Cavendish Corporation Staff: How It Works: Science and Technology. 20 volumes, 3rd Edition, Marshall Cavendish, 2003, ISBN 978-0-7614-7314-5 , p. 498.
  3. ^ Heinz-Gerhard Franck, André Knop: Coal Refinement: Chemistry and Technology . Springer, 1979, ISBN 978-3-540-09627-6 , urn : nbn: de: 1111-201111181838 .
  4. ^ Koppers : Coal Tar Distillates
  5. ↑ Otto Kruber, Armin Raeithel: On the knowledge of the stink coal tar anthracene oil. In: Chemical Reports. 85, 1952, pp. 327-333, doi: 10.1002 / cber.19520850410 .