A reactor for converting scrap tire material into output products, while allowing controlling the characteristics of the products within certain ranges, includes a pre-processing zone maintained at a first average temperature, at least one primary processing zone maintained at a second average temperature, at least one secondary processing zone maintained at a third average temperature, a post-processing zone that cools scrap tire material to a fourth temperature, at least one water injector that introduces water into the interior of the secondary processing zones, and potentially also the primary zone, and a transport mechanism that moves, and may mix, scrap tire material across the pre-processing zone, primary processing zone, secondary processing zone, and post-processing zone.