Improving mixing behaviour in new design of carbon black gas furnace using 3D CFD modelling

The gas furnace process for the production of carbon black was applied in the first half of this century, but was replaced by the cheaper oil furnace process. A possible new application - the production of carbon black from associated oilfield gas - raises new interest in this process. To investigate the viability of this application, which is critically dependent on carbon black yield and particle size, a new furnace design is tested. Preliminary tests had shown, that carbon black with a particle size comparable with commercial grades is obtainable with the new furnace design. First carbon black concentration measurements established a process yield far lower than initially hoped for. The use of a 3-dimentional computational fluid dynamics (CFD) model found the low yield to be partly attributable to poor mixing conditions, which enabled a specific design modification, leading to a considerable improvement in process yield. The CFD model is gradually being improved as more experimental data becomes available to verify the predictions.