Valorization of waste waxed corrugated cardboard via pyrolysis for recovering wax

Abstract

Abstract Corrugated cardboard (CCB) comprises a substantial portion of municipal solid waste, of which ~5% is wax coated CCB (WCCB) to enhance its performance. WCCB cannot be recycled, making it a suitable resource to recover wax and produce char. The WCCB was characterized for its extractable wax, lignin, and carbohydrate contents and by thermogravimetric analysis to study its thermal degradation behavior. WCCB was preliminarily examined by pyrolysis‐ gas chromatography–mass spectrometry to determine product composition. WCCB samples were then pyrolyzed in auger and tube reactors at 450, 500, and 550°C, and their pyrolysis wax‐oil and char products characterized. WCCB and char were subjected to proximate, ultimate, surface area, analyses. The highest char yield was 36% at 450°C, and the highest wax‐oil yield was 53% at 550°C in the tube reactor. The wax‐oil fraction contained mainly alkanes, alkenes, and dienes (C 9 –C 36 ), and chain length decreased with pyrolysis temperature. This wax fraction could be recovered and used as bunker fuel (C 12 –C 40 ) or further converted to diesel (C 10 –C 20 ).