Valorization of Automobile Shredder Residue Using Indirect Gasification

Abstract

Dual fluidized bed (DFB) gasification offers the possibility to convert solid fuels into a valuable gas, comprised of syngas, and hydrocarbons that can be readily handled in petrochemical units. DFB gasifiers are especially suitable for nonhomogeneous fuels, such as waste fractions. In this work, the possibility to use DFB gasification as a recycling/valorization method of automobile shredder residue is investigated. The gasification tests were carried out in the Chalmers 2–4 MWth gasifier over 4 days. The effects of ash on the gas and tar compositions, as well as on the activity of the bed inventory, were evaluated. The results show that 60% of the total carbon in the fuel can be recovered in the form of a permanent gas, whereby the produced gas contains 12%mol of C2–3 hydrocarbons. The tar levels measured in the produced gas were high, although it was clear that decomposition into monomer-like compounds occurred in the reactor, which resulted in the production of valuable petrochemical compounds, corresponding to 8–9% of the carbon in the feed. Using a higher operating temperature was found to be beneficial in terms of obtaining a higher gas yield, regardless of the level of ash enrichment in the system. The high ash levels in the fuel feed did not negatively affect the technical operation of the fluidized bed. Possible routes of carbon recovery are discussed.