Oil refinery

The Oil refinery is a fluid-processing building used to convert crude oil and related inputs into the petroleum products needed for plastic, sulfur, fuel, lubricant, and many later game recipes. It is one of the core buildings in the oil-processing chain, and it must have a recipe selected before it can operate.

The refinery has several available recipes, with the exact set depending on researched technologies. Basic oil processing turns crude oil into petroleum gas. Advanced oil processing uses crude oil and water to produce heavy oil, light oil, and petroleum gas. Coal liquefaction consumes coal and steam together with heavy oil to produce heavy oil, light oil, and petroleum gas. Simple coal liquefaction consumes coal, calcite, and sulfuric acid and produces heavy oil. One recipe must be chosen manually before the refinery will begin processing.

When the refinery is working, a flame comes out of the chimney. If it is not running, the first thing to check is whether a recipe has been selected. Another common issue is output blockage: the refinery stops working if any of its products are not properly drained. For example, if heavy oil reaches 100.0 at an output, the refinery cannot continue producing the other fluids.

Practical use usually centers on keeping all outputs moving smoothly, especially when using advanced oil processing or coal liquefaction, since those recipes generate multiple fluids at once. A refinery that produces more of one fluid than the rest can stall the entire chain if the excess fluid has nowhere to go. To avoid this, players typically ensure that tanks, pipes, cracking setups, or consuming machines are available for every output stream before scaling up refinery capacity.