Provided herein are systems and methods for removing halogens and sulfur from used oil. The used oil is heated and aerated, followed by rapid vaporization and cooling. The cooled oil is then subjected to an electrical field before being filtered.

A fuel and/or lubricant system for an engine can include an engine component configured to be in fluid communication with the fuel and/or lubricant, and an alternating current (AC) source electrically connected to the engine component to create an electric field of alternating polarity to subject particles within the fuel and/or lubricant to dielectrophoresis as the fuel and/or lubricant passes through the electric field to prevent deposits from forming on the engine component. In certain embodiments, the engine component can be a filter screen configured to filter the fuel and/or lubricant to subject particles within the fuel and/or lubricant to dielectrophoresis as the fuel and/or lubricant passes through the filter screen.