Refining is the industrial process of purifying crude oil and natural gas into more useful products. The main oil-refining process is distillation, whereas the main gas-refining processes are amine treating and cryogenic liquefaction. Refining is part of the downstream sector of the petroleum industry and plays an essential role in the product life cycle.
Environmental policies, taxes, and emission criteria are major drivers of change in the refining processes and vary by region. Crude oil and natural gas prices are critical to the industry, as is rising product-quality demand. A shift in the supply and demand centers and trade flows, as well as global warming and severe weather conditions that damage facilities, add to the issues that alter the refining world.