From RimWorld Wiki
While the refinery is selected, click "Bills" then "Add Bill" to add an order to produce chemfuel:
- The "Make chemfuel from wood" bill will turn 70 wood logs into 35 chemfuel.
- The "Make chemfuel from organics" bill will turn 3.5 nutrition worth of food ingredients in 35 chemfuel.
- Although not recommended, you can use meals to create chemfuel.
- Most raw ingredients have a nutrition value of 0.05. For such ingredients, 3.5 nutrition requires 70 units, which is the same quantity required of wood.