Systems and methods for reducing or eliminating corrosion of components of a reactor system, including a supercritical water gasification system, are described. The reactor system may include various system components, such as one or more pre-heaters, heat exchangers and reactor vessels. The system components may be configured to receive a reactor fluid corrosive to an inner surface thereof and to separately receive a protective fluid that has a higher density and is substantially immiscible with the reactor fluid. A rotating element may be configured to generate a rotational force that forces at least a portion of the protective fluid to flow in a layer between the reactor fluid and at least a portion of the inner surface, the layer operating to reduce corrosion by forming a barrier between the reactor fluid and at least a portion of the inner surface.