Process for recovering carbon black and hydrocarbons from used tires

Abstract

The invention is a process for economically recovering carbon black, oil and fuel gas from used tires. Used tires are physically fragmented. The fragments are pyrolized at slightly subatmospheric pressure in a reactor while process char is being recycled to increase heat transfer and avoid coke on heat transfer surfaces. Entrained char is separated from the vapor phase products of the pyrolysis, and the vapor phase products of the pyrolysis are then fractionated into oil and fuel gas. A preferred embodiment condenses reactor vapors in two stages at two temperature levels to separate dust from an oil-dust mixture, without water in the first stage and light oil in the second stage. The fuel gas can be compressed and burnt to provide process heat. The entrained char dust and some heavy oil is returned to the reactor. Solid phase pyrolysis products are stripped of trash and milled to carbon black. Carbon black is mechanically separated from the effluent air stream of the mill and formed into pellets with added water and dried.