An apparatus and method are provided for processing hydrocarbon feeds. The method enhances the conversion of hydrocarbon feeds into conversion products, such as ethylene. In particular, the present techniques utilize a high-severity thermal pyrolysis reactor that exposes a feed at a peak pyrolysis gas temperature ≧1540° C. to produce a reactor product comprising ethylene and acetylene and has a C3+ to acetylene weight ratio ≦0.5. Then, the method separates a product comprising tars and/or solids from at least a portion of the reactor product and converts at least a portion of the remaining reactor product into a conversion product, such as ethylene.