Pyrolysis of scrap tyres pretreated by waste coal tar

Abstract

For disposal of scrap tyres, there have been a lot of studies done by previous researchers, but it yet remains a longstanding challenge in practice. To find a solution for this problem, the feasibility of a proposed approach in a laboratory scale was tested. The pyrolysis of scrap tyres pretreated by waste coal tar (noted as “as-pretreated” tyres) was performed in a batch reactor at atmospheric pressure. Waste coal tar was used to modify the scrap tyres to improve the pyrolysis efficiency of scrap tyres input and the quality of the product tar. The swelling behavior of scrap tyres soaked in waste coal tar at 10 °C, effect of pyrolysis temperature on the product yields, and the synergies during pyrolysis of the as-pretreated tyres and co-pyrolysis of scrap tyres/waste coal tar mixture were all investigated in detail. The results observed found that by comparison of the calculated yields and the observed experimental yields for pyrolysis products, the synergy from co-pyrolysis of scrap tyres/waste coal tar mixture boosted the gas yield without increasing the tar yield. In contrast, the synergy during pyrolysis of the as-pretreated tyres could enhance the tar yield, but reduced the gas and char yields. According to the distillation range analyses of the tar, more light fractions were found in the tar from pyrolysis of the as-pretreated tyres, in which the gasoline fraction, diesel fraction and kerosene fraction were 38.4 wt%, 46.8 wt% and 50.2 wt%, respectively. This work is expected to be helpful in further use of scrap tyres.