The pyrolysis of acetylene below 550°C

Abstract

Abstract The polymerization of acetylene below 550° has been examined in a static system. For unpacked vessels it was found possible to obtain reproducible results, from which second‐order rate constants, and an activation energy of 46·7 | 2 kcal., have been obtained. The effect of a large number of additives has been examined, with particular reference to compounds which might be present as impurities in the acetone in which commercial acetylene is dissolved. The results were mainly negative, catalysis being observed only in the presence of diacetyl. Nitric oxide considerably lengthened the induction period, while alkyl halides and traces of some metals led to the replacement of polymerization by decomposition. In packed vessels the reaction is controlled mostly by the surface, and, with some packings, it is more rapid than in unpacked vessels.