Ab der-Halden
Ab der-Halden : A continuous process for distilling coal tar. It is operated under reduced pressure with the heat provided by live, superheated steam. This provides a clean separation of the products, without cracking. Developed in France in the 1920s by C. Ab der-Halden who formed the company PROABD to exploit it. PROABD is now a division of BEFS Technologies, Mulhouse, France, which offers this process and others under the same trade name. Not to be confused with the Abderhalden reaction in biochemistry