A refinery is a massive industrial operation where a specific chemical engineering process is used to convert raw materials into usable products. One example is a refinery that turns crude oil into a range of products, such as petroleum, diesel, and heating oil. Sugar refineries take harvested cane or beets and convert the plants’ natural sugars into a crystallized form for sale in grocery stores or use in food production. Metal refineries may process a variety of metals, such as aluminum, copper, and steel, for a variety of purposes like manufacturing steel beams for use in the construction industry.