Oil Refinery

The Oil Refinery is a refining building used to process Crude Oil into Refined Oil and Hydrogen. It is one of the first facilities that turns raw oil extraction into useful chemical products, and it remains important throughout the game because many advanced production chains still depend on Refined Oil, especially those involving plastics and later chemical intermediates.

By default, the refinery uses Plasma Refining to convert Crude Oil into Refined Oil and Hydrogen. After researching X-ray Cracking, it can also convert Refined Oil into Energetic Graphite and Hydrogen. After researching Reformed Refinement, it gains another recipe that combines Hydrogen and Coal to produce Refined Oil. These alternate recipes let the refinery act as a balancing tool for oil-derived products, and their usefulness changes as production needs shift over the course of a save.

A refinery has a footprint of 7×4 and accepts Sorters on three of its sides, for a total of nine Sorters. The round end of the short side cannot take a Sorter. Because the building produces or consumes multiple products, routing needs careful planning. If the output lines are not separated properly, Refined Oil and Hydrogen will mix and can clog the line. Using Sorter filtering or Splitter filtering keeps the products separated cleanly.

The early game oil setup is especially important because the refinery is the only practical source of Hydrogen for red science until other methods are available. One crude oil refining line produces more Refined Oil than Hydrogen, so if the goal is to make Hydrogen from the refinery chain alone, the output is naturally unbalanced. In practice, two refineries using X-ray Cracking are needed for every refinery doing Plasma Refining if the Hydrogen is being cycled back through the cracking process.

Useful points for planning refinery lines:

• X-ray Cracking directly converts 1 Refined Oil into 1 Energetic Graphite and 1 Hydrogen.
• A typical three-refinery X-ray Cracking setup produces 15 Energetic Graphite per minute and 30 Hydrogen per minute.
• The cracking output lines up closely with Energy Matrix production, which is its main use.
• Outside that purpose, X-ray Cracking is usually less efficient than simpler direct production methods for Hydrogen and Energetic Graphite.
• Reformed Refinement converts 2 Refined Oil, 1 Hydrogen, and 1 Coal into 3 Refined Oil.
• Combined with Plasma Refining, this can eliminate Hydrogen byproducts while still producing Refined Oil.
• With a one-time startup input, Reformed Refinement plus X-ray Cracking can support Coal-to-Energetic-graphite conversion at a 1:1 ratio.

The refinery is also power-hungry compared with early manufacturing buildings, so expansion should be planned with available generation in mind. Since both Refined Oil and Hydrogen can be burned as fuel, excess output can be routed to Thermal Power stations to prevent backups. A nearby power setup and Splitter priority handling make it easier to absorb surplus products and keep the oil system stable.