Application of coal conversion technology to tire processing

Tire recycling has been carried out using technology most commonly develope d for coal conversion processes trying to take advantage of well-known reac tors. Two different batch reaction systems (tubing bomb reactors and magnet ically stirred autoclave) and a continuous reactor (swept fixed bed reactor ) were tested. In addition, the influence of hydrogen pressure (ranging fro m 1 to 10 MPa) was assessed together with the influence of an inert or a hy drogenating atmosphere. Independently of the reactor used (tubing bomb reac tors or magnetically stirred autoclave), the initial hydrogen pressure and the atmosphere, the 100% of the organic matter conversion was obtained in a ll the runs when batch reactors were used. When the semicontinuous reactor was used, slightly lower conversions were obtained, probably due to the dep osition of products on the surface of the solid products. In all the experi ments, conversion products were always oils and gases (comprised mainly of light hydrocarbons) plus a rich in carbon black solid residue. It was obser ved that the distribution between oils and gases was a function of the reac tor type and in some cases a function of the hydrogen pressure. Oils were c haracterised by thin layer chromatography coupled to a flame ionisation det ector (TLC-FID) and by simulated distillation. Different results in oils co mposition were obtained as a function of the reactor type and hydrogen pres sure. (C) 1999 Elsevier Science B.V. All rights reserved.