Catalytic degradation of acrylonitrile-butadiene-styrene into fuel oil 1. The effect of iron oxides on the distribution of nitrogen-containing compounds

The thermal and catalytic degradation of acrylonitrile-butadiene-styrene copolymer (ABS) was performed at 400 °C in static nitrogen atmosphere, by semibatch operation. γ-Fe₂O₃, an Fe₃O₄-C composite, and α-FeOOH Were used as catalysts, in two contact modes: Either mixed with the polymer or in contact with the volatile degradation products of ABS. All iron oxides decrease the Concentration of nitrogen (N) in ABS degradation oil. Reactions in a flow-type reactor with 4-phenylbutyronitrile as model N-containing compound show that α-FeOOH is active at low temperatures (250-300 °C) in converting heavy N-containing compounds into light aliphatic nitriles. XRD analysis proved that during reaction α-FeOOH was transformed into Fe₃O₄ in several steps, with α-Fe₂O₃ as intermediary compound.