Abstract: A method to demetal and de-ash oil feedstock. The method includes adding direct steam and sulfuric acid to oil feedstock to form acid treated oil, the sulfuric acid to strip the oil feedstock of metals, adding de-emulsifier to the acid treated oil feedstock to aid in phase separation, and settling the acid treated oil feedstock to separate into clarified oil, water, and a rag layer. The method includes centrifuging the clarified oil with a centrifuge running in a 3 phase configuration to remove water and solids from the clarified oil, and ensuring proper temperature and adding triethanol amine (TEA) to the centrifuged clarified oil to flocculate asphaltenes in the centrifuged clarified oil, creating TEA treated oil. The method includes centrifuging the TEA treated oil with a centrifuge running in a 2 phase configuration to remove the asphaltenes from the TEA treated oil and create marine fuel.