Role of the Reactor Surface in Pyrolysis of Light Paraffins and Olefins

Abstract

Surface reactions occurring during pyrolysis still need considerable clarification. These reactions probably include the initiation and termination of free radicals, coking, and the formation of metal oxides, metal carbides, and metal sulfides. Earlier findings at Purdue University (1-4), including those of Tsai and Albright (5), have indicated the importance of these surface reactions during the pyrolysis of light hydrocarbons. More quantitative information is, however, still needed particularly regarding the surface reactions of light paraffins and olefins as a function of the materials of construction of the reactor. In order to accentuate the surface reactions, the present investigation was limited to relatively low temperatures (450-750°C) and to long space times (5-30 sec). For such relatively low temperatures, gas-phase reactions and/or initiation of reactions are slight; surface reactions, however, often occur readily at such conditions. The surface reactions were investigated in four tubular flow reactors: 304 stainless steel, 410 stainless steel, Incoloy