Preparation of submicron-/nano-carbon from heavy fuel oil ash and its corrosion resistance performance as composite epoxy coating

Abstract

Heavy fuel oil ash (HFOA), an industrial waste material generated due to incomplete combustion of heavy fuel oil in a power plant, was used to prepare submicron-/nano-carbon by pyrolysis and ball milling. The developed submicron-/nano-carbon was characterized to determine its morphology, structure, and chemical composition using field-emission scanning electron microscopy, Raman spectroscopy, X-ray diffractometer, energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The prepared submicron-/nano-carbon was used to develop a low cost and highly corrosion-resistant composite coating. The performance of the developed composite coating, in protecting mild steel against corrosion, was investigated using electrochemical impedance spectroscopy, potentiodynamic polarization and salt spray techniques. The electrochemical results indicate better anti-corrosion performance of the developed composite coatings, as evident from the enhancement of the coating impedance by 63 and 146% and the corrosion resistance efficiency by 92 and 98% at 0.5 and 1.0% of the submicron/nano carbon content, respectively, compared to the neat epoxy. Moreover, the adhesion of the composite coating was better than that of the neat epoxy coating. Based on the results of the performance of the developed composite epoxy coating material, it is found that the HFOA can be utilized to produce submicron/nano-carbon for its usage as a filler in the epoxy coating, which would solve the problem of the disposal of HFOA on one side and enhance the protective properties of the epoxy coating on the other side; thus resulting in technical, economic and environmental benefits.