Scientific African 16 (2022) e01208 Contents lists available at ScienceDirect Scientific African journal homepage: www.elsevier.com/locate/sciaf Biomass and plastic co-pyrolysis for syngas production: Characterisation of Celtis mildbraedii sawdust as a potential feedstock  Isaac Mensah a,∗ , Julius Cudjoe Ahiekpor a , Nadine Herold b , Edem Cudjoe Bensah a , Alexander Pfriem b , Edward Antwi c,d , Bright Amponsem a a Department of Chemical Engineering, Kumasi Technical University, Box 854, Kumasi, Ghana b Faculty of Wood Engineering, Eberswalde University for Sustainable Development, Alfred-Möller-Str. 1, Eberswalde, Germany c Department of Mechanical Engineering, Kumasi Technical University, Box 854, Kumasi, Ghana d Department of Waste and Resource Management, University of Rostock, Justus-von-liebig-weg 6, 18057, Germany a r t i c l e i n f o Article history: Received 27 August 2021 Revised 6 April 2022 Accepted 28 April 2022 Editor: Dr. B. Gyampoh Keywords: Celtis mildbraedii sawdust Physicochemical Characterisation Co-pyrolysis Syngas production Ghana a b s t r a c t Celtis mildbraedii sawdust (CMS) from Ghana was characterised to investigate its suit- ability with polyethylene terephthalate (PET) for syngas production via co-pyrolysis. The physical and chemical properties assessed include proximate and ultimate compositions, pH value, higher heating value (HHV), and lignocellulosic composition. Also, the ther- mal behaviour at different heating rates (5, 10, and 20 K/min) and qualitative predic- tion of organic compounds of CMS were examined using thermogravimetric analysis (TG/DTG) and NIR spectroscopy techniques, respectively. Results of proximate analysis (moisture = 17.15 ± 0.0 wt.%, ash = 1.13 ± 0.4 wt.%, volatile matter = 68.39 ± 0.4 wt.%, fixed carbon = 13.33 ± 0.8 wt.%); ultimate analysis (C = 48.51 wt.%, H = 6.66 wt.%, N = 0.51 wt.%, S = 0.02 wt.%, O = 44.30 wt.%); pH values (cold phase = 7.60, hot phase = 6.30); HHV (15.37 – 18.03 MJ/kg); and lignocellulosic composition (extrac- tives = 13.80 ± 0.57 wt.%, hemicellulose = 21.95 ± 3.89 wt.%, lignin = 17.35 ± 0.35 wt.%, cellulose = 46.90 ± 2.97 wt.%) were obtained. The maximum mass loss was 83.48% at 289.8 °C at 5 K/min. It was concluded that CMS is a highly potential biomass resource for syngas production with an empirical formula of CH 1.64 O 0.69 N 0.009 S 0.0001 . © 2022 The Author(s). Published by Elsevier B.V. on behalf of African Institute of Mathematical Sciences / Next Einstein Initiative. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) Introduction Lignocellulosic biomass sources such as wood processing waste, forestry waste, and agricultural residues have been recog- nised as significant renewable resources for energy generation. [1,2]. According to Varma et al. [3], 12 –25 kg sawdust is generated whenever 100 kg of wood is processed in sawmills. It is estimated that sawmills in Ghana generate close to 81,000 t/yr of sawdust. However, converting these wastes to biofuels is at the early stages of development in Ghana and other developing countries [4,5].  Editor by Dr Benjamin Gyampoh ∗ Corresponding author. E-mail address: isaacokmensah@yahoo.com (I. Mensah). https://doi.org/10.1016/j.sciaf.2022.e01208 2468-2276/© 2022 The Author(s). Published by Elsevier B.V. on behalf of African Institute of Mathematical Sciences / Next Einstein Initiative. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/)