the present invention is a method for using a batch centrifuge to separate the granulated material of a container from whatever liquid residue remains within the container . though this technology is suitable for many diverse applications , a primary objective is the separation of the recyclable plastic of a motor oil container from the remaining reusable motor oil within the container after the container has ostensibly been emptied . the apparatus may be utilized as a compact , free - standing size reduction and reclaiming device at the location where the container is used . it uses neither a solvent nor a wash process and reclaims the oil in a suitable state for reprocessing . in a second method , a rinsing mechanism is employed by which a residual liquid waste , such as soap , may be concentrated and separated without introducing this residual liquid waste in dilute form into the waste water treatment process . a further method provides for the re - orientation of the granulated material so that complete removal of the liquid waste is achieved during the centrifugal process .