what is refining

Refining is the process of purifying a substance or form. It is usually used to refer to natural resources that are almost in a usable form but are more useful in their pure form. Refining crude oil is a common example of the refining process. Petroleum refineries convert crude oil into petroleum products for use as fuels for transportation, heating, paving roads, and generating electricity, and as feedstocks for making chemicals. Refining breaks crude oil down into its various components, which are then selectively reconfigured into new products. Refining can be accomplished through various methods, including distillation, fractionation, extraction, and chemical reactions. The process of refining can also involve rearranging molecules rather than splitting them to add value. Refining can improve or perfect something by introducing subtleties or distinctions.