Oxy-fuel combustion is a combustion technology that uses oxygen and fuel to create a flame. It is used in many industrial processes, such as metal melting and welding, to produce heat and light. The oxygen is usually provided by an air separation unit (ASU), while the fuel is typically a combustible gas such as natural gas, propane, or hydrogen. In oxy-fuel combustion, the combustion process is more efficient and produces fewer emissions than traditional air-fuel combustion.