Abstract: A process for re-refining used lubricating oil (ULO), much of which is used motor oil (UMO) relies on more rapid heating, turbulent flows, higher peak temperatures, to achieve rapid thermal cracking, even including metal-bearing additives without catalysts, compared to conventional refining of crude oil and conventional recycling processing of UMO. By thermally cracking this way and scrubbing with recycled, processed liquids from the flow stream, a process readily removes metal-bearing hydrocarbons in typical lubricating oil additives. Those bonded metals consigned to heavy fraction “bottoms,” are commonly non-removable by other recycling schemes. Long chain polymers including paraffins are broken into lighter hydrocarbons with properties typical of fuels containing olefins, naphthenes, and the like. Data and analysis reveal low solids, effective metal removal, comparatively low viscosity and boiling points, and greatly reduced sulfur content in fuel and oil products resulting.

Abstract: Crude oil fractions, fossil fuels, and organic liquids in general in which it is desirable to reduce the levels of fused-ring compounds, aromatics, and olefins are combined with an aqueous phase to form an emulsion and treated with ultrasound with the effect of opening rings in the fused-ring compounds, saturating aromatics, and converting the olefins to paraffins. In fossil fuels and crude oil fractions, the process raises the API gravity, and in diesel fuels, the process raises the cetane index and thereby improves performance. In fuels and fractions with sulfur-containing and nitrogen-containing components, the process reduces the level of these compounds. The process can be performed both with and without the added presence of hydrogen peroxide. The invention is performed either as a continuous process or a batch process.