Evidence of coal and tire interactions in coal-tire coprocessing for shortresidence times

In this paper, the factors controlling the hydrocoprocessing of coal and wa ste tires in tubing bomb reactors are studied. The fixed experimental condi tions were 400 degreesC and 10 MPa of H-2 pressure. Five different coproces sing times (60, 30, 10, 5 and 3 min) and two coal-tire ratios (80% coal-20% tire and 20% coal-80% tire) were the studied variables. Results are compar ed with those obtained when coal and tire were processed by isolate. At the se conditions, it was observed that reaction time has no effect on tire con version in obtaining the possible maximum value. However, with coal, reacti on time is a fundamental variable because total conversion depends on it. I n tire, reaction time has no effect on total conversion, but it affects pro duct distribution in obtaining lower oils yields at longer reaction times d ue to hydrocracking reactions. In hydrocoprocessing of both materials, a sy nergism in asphaltenes formation is observed at short reaction times. This synergism has been explained by the inter-reactions between coal and tire r adicals. Besides, tire addition to coal hydrogenation processes improves th e quality of the oils. (C) 2001 Elsevier Science B.V. All rights reserved.