the process described herein presents a unique method of separating and converting polymers and hydrocarbon composites to light / medium weight hydrocarbons from polymer and hydrocarbon composites waste . the method involves the removal of moisture from the hydrocarbon composite and / or polymer waste followed by or in conjunction with a catalytic reaction which takes place at slight negative pressure in anaerobic conditions . the light / medium weight hydrocarbons are then recovered in the vapor phase . the vapors are condensed and separated by conventional techniques . residual solids , substantially free of hydrocarbons and polymers may be furthered processed and recycled by conventional means . the conversion process has also been applied to natural occurring heavy and low grade hydrocarbon deposits such as oil and tar sands .