There are three broad types of oil extraction:  In large-scale industrial oil extraction you will often see some combination of pressing, chemical extraction and/or centrifuging in order to extract the maximum amount of oil possible. Cooking oil can either be unrefined, or refined using one or more of the following refinement processes (in any combination):   Filtering, a non-chemical process which screens out larger particles, could be considered a step in refinement, although it doesn't alter the state of the oil. Most large-scale commercial cooking oil refinement will involve all of these steps in order to achieve a product that's uniform in taste, smell and appearance, and has a longer shelf life. Cooking oil intended for the health food market will often be unrefined, which can result in a less stable product but minimizes exposure to high temperatures and chemical processing. You can also extract oil from various seeds like, Coconut, peanuts, Sesame, walnuts and many more at home. For that you can use any cold press oil maker machine. Proper disposal of used cooking oil is an important waste-management concern. Oil can congeal in pipes, provoking blockages. Because of this, cooking oil should never be dumped in the kitchen sink or in the toilet bowl. The proper way to dispose of oil is to put it in a sealed non-recyclable container and discard it with regular garbage. Placing the container of oil in the refrigerator to harden also makes disposal easier and less messy. Cooking oil can be recycled. It can be used as animal feed, directly as fuel, and to produce biodiesel, soap, and other industrial products. In the recycling industry, used cooking oil recovered from restaurants and food-processing industries (typically from deep fryers or griddles) is called recycled vegetable oil (RVO), used vegetable oil (UVO), waste vegetable oil (WVO), or yellow grease. Yellow grease is used to feed livestock, and to make soap, make-up, clothes, rubber, detergents, and biodiesel fuel. Used cooking oil, besides being converted to biodiesel, can be used directly in modified diesel engines and for heating. Grease traps or interceptors collect fats and oils from kitchen sinks and floor drains which would otherwise clog sewer lines and interfere with septic systems and sewage treatment. The collected product is called brown grease in the recycling industry. Brown grease is contaminated with rotted food solids and considered unsuitable for re-use in most applications.