Preparation of bio-oil by catalytic pyrolysis of corn stalks using red mud

Abstract: Red mud is a solid waste residue with alkaline nature (pH>12)-originating from the Bayer process in the production of alumina, which was probed in catalytic pyrolysis to determine its feasibility as a solid catalyst for bio-oil formulation. The red mud was characterized using X-ray fluorescence, XRD (X-ray diffraction), TG-DTG (thermogravimetry-derivative thermogravimetry), BET (surface area and pore size analyzer) measuring and testing techniques. Experiments of non-catalytic and catalytic pyrolysis of 40-60 mesh size corn stalk powder were channelled for bio-oil production in a fixed bed reactor. It was ascertained that adding different proportions of red mud had minute influence on bio-oil production rate and product distribution. The study signaled that liquid yield from the catalytic pyrolysis was lower than that from non-catalytic pyrolysis. Through a series of bio-oil characterization, it was encountered that the most obviously change in the bio-oil from catalytic pyrolysis was significant acidity reduction (pH>4). Meanwhile, the content of ketones and phenols was enhanced. Hence, the co-processing of agricultural waste and by-products alumina industry may offer an economical and environmentally friendly way of catalytic pyrolysis with abbreviating the red mud environmental effects.