Simple coal liquefaction

Simple coal liquefaction is a coal-to-petrochemical recipe that converts coal together with sulfuric acid and calcite into heavy oil only. It is introduced as an alternative, simpler coal liquefaction recipe that produces only Heavy oil; that Heavy oil can then be processed further by Heavy oil cracking to light oil and other downstream oil-processing chains. Simple coal liquefaction appears as a separate recipe option alongside the standard Coal liquefaction route and fits into the oil-processing tech tree as an intermediate or starter source of Heavy oil.

Simple coal liquefaction is unlocked as a technology prereq for Coal liquefaction and is tied to the presence of Calcite in the tech requirements. It is useful in scenarios and locations where establishing the full Coal liquefaction chain or Steam production is impractical or expensive. On the Space platform, for example, producing Steam is more difficult than producing Sulfuric acid or Calcite; Steam production on the Space platform requires using Nuclear fuel, which in turn needs transport from Vulcanus. By contrast, Sulfuric acid, Coal and Calcite can be obtained from meteoric resources or manufactured locally on the Space platform, making Simple coal liquefaction a practical way to bootstrap Heavy oil production there without relying on Steam or Nuclear fuel shipments.

• Inputs and outputs: Simple coal liquefaction consumes Coal, Sulfuric acid and Calcite and yields only Heavy oil. The recipe’s internal identifier is simple-coal-liquefaction.
• Role in progression: It serves as a simpler precursor route to obtain Heavy oil and is a prerequisite technology for the full Coal liquefaction process. Researching the required Calcite technology is sufficient to unlock Simple coal liquefaction; it is not necessary to physically mine Calcite from Vulcanus — unlocking can be completed on the Space platform by obtaining Calcite through processing meteors or other means.
• Practical advantages: Because it produces only Heavy oil, Simple coal liquefaction lets players dedicate a production line solely to Heavy oil and then use Heavy oil cracking to derive Light oil and other petroleum products when needed. This separation simplifies logistics and startup on isolated bases such as the Space platform.
• Use cases: Best used to bootstrap an oil supply where Steam or Nuclear fuel logistics are constrained, to feed Heavy oil cracking lines, or to provide Heavy oil input for downstream petrochemical facilities without committing to the full Coal liquefaction infrastructure.

Simple coal liquefaction is therefore a targeted, tech-gated recipe that makes Heavy oil accessible in environments where the standard Coal liquefaction route or Steam-dependent setups are impractical.