Catalytic effect of kaolin on the pyrolysis of sawdust and poultry wastes to produce Biochar for CO2 sequestration

Abstract

There is an increasing realisation that biomass and organic waste are valuable feedstock for pyrolysis process that produces biochar, bio-oil and biogas. The Oxides such as aluminium oxide (Al2O) and calcium oxide (CaO) could have catalytic effect on biochar production from biomass. To study the catalytic effect of Kaolin, the raw kaolin was calcinated, acid modified and characterised. Saw dust (SD) and Poultry waste (PW) biomass were impregnated with the modified Kaolin at different ratio (25wt%, 50wt%, and 75wt%)and subjected to pyrolysis at temperature between 300oC and 600oC.The biochar produced were analysed, characterised and the carbon sequestration potential was evaluated hypothetically. The result showed that co-pyrolysis of SD impregnated with 25wt% of Kaolin (SDK25) increased the biochar yield by 25wt% and carbon sequestration potential by 10wt% as compared to PW impregnated with 25wt% Kaolin (PWK25) which increased the biochar yield by 15wt% and carbon sequestration potentials by 5wt%. Fourier Infrared spectroscopy (FT-IR) spectra displayed that all biochars at 500oC contain C-H alkyl group and aromatic band at 1571cm-1which may impact positively on nutrient and water retention. Scanning Electron Microscope (SEM)and X-ray diffraction (XRD) analysis showed the development of well define pores for biochar produced at 500oC, while the Brunauer–Emmett–Teller (BET) analysis showed that the biochar produced from the two biomass has a good surface structure and characteristics (surface area: 410m2 .g-1 and 276.3m2 .g-1 ) and could be employed as adsorbent in CO2 adsorption.