Effect of eggshell- and homo-type Ni/Al2O3 catalysts on the pyrolysis of food waste under CO2 atmosphere. (15th September 2021)

• Record Type: Journal Article
• Authors: Valizadeh, Soheil; Ko, Chang Hyun; Lee, Jechan; Lee, See Hoon; Yu, Yeon Jeong; Show, Pau Loke; Rhee, Gwang Hoon; Park, Young-Kwon
• Is Part Of: Journal of environmental management. Volume 294(2021)
• Publication Date: 2021-09-15
• Subjects: Food waste -- Pyrolysis -- Eggshell-type catalyst -- CO2 -- Nickel; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2021.112959
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: This study highlights the potential of pyrolysis of food waste (FW) with Ni-based catalysts under CO2 atmosphere as an environmentally benign disposal technique. FW was pyrolyzed with homo-type Ni/Al2 O3 (Ni–HO) or eggshell-type Ni/Al2 O3 (Ni-EG) catalysts under flowing CO2 (50 mL/min) at temperatures from 500 to 700 °C for 1 h. A higher gas yield (42.05 wt%) and a lower condensable yield (36.28 wt%) were achieved for catalytic pyrolysis with Ni-EG than with Ni–HO (34.94 wt% and 40.06 wt%, respectively). In particular, the maximum volumetric content of H2 (21.48%) and CO (28.43%) and the lowest content of C2 –C4 (19.22%) were obtained using the Ni-EG. The formation of cyclic species (e.g., benzene derivatives) in bio-oil was also effectively suppressed (24.87%) when the Ni-EG catalyst and CO2 medium were concurrently utilized for the FW pyrolysis. Accordingly, the simultaneous use of the Ni-EG catalyst and CO2 contributed to altering the carbon distribution of the pyrolytic products from condensable species to value-added gaseous products by facilitating ring-opening reactions and free radical mechanisms. This study should suggest that CO2 -assisted catalytic pyrolysis over the Ni-EG catalyst would be an eco-friendly and sustainable strategy for disposal of FW which also provides a clean and high-quality source of energy. Graphical abstract: Image 1 Highlights: CO2 demonstrated a higher potential to produce gaseous products than N2 . Higher gas yield and lower bio-oil was obtained using Egg-shell than homo catalyst. Eggshell catalyst exhibited higher stability compared to homo catalyst. H2 -rich gas was achieved by concurrent applying egg-shell catalyst and CO2 .