Open AccessSome experiments on vacuum distillation
Author(s) -
Cecil Reginald Burch
Publication year - 1929
Publication title -
proceedings of the royal society of london. series a, containing papers of a mathematical and physical character
Language(s) - English
Resource type - Journals
eISSN - 2053-9150
pISSN - 0950-1207
DOI - 10.1098/rspa.1929.0070
Subject(s) - vacuum distillation , distillation , kerosene , cracking , condensation , decomposition , mercury (programming language) , evaporation , chemistry , materials science , petroleum engineering , thermodynamics , organic chemistry , engineering , physics , computer science , programming language
Crude petroleum and various petroleum derivatives have been distilled under conditions practically equivalent to evaporation into a perfect vacuum. Derivatives of very high molecular weight can be fractionated in this way without detectable decomposition. Decomposition (“cracking”) sets in quite suddenly, at temperatures varying from 307° to 340°C. for the oils tried. Greases and oils can be produced having exceedingly low vapour pressures at room temperature: the former permit the free use of ground joints in high- vacuum systems (10-6 mm.): the latter can replace mercury in condensation pumps, and the liquid-air trap is then unnecessary in many cases,e. g. , the exhaustion of thermionic valves.