Factorio oil processing ratio: refineries and cracking
To turn all crude oil into petroleum gas with advanced oil processing, build 20 oil refineries, 5 chemical plants cracking heavy oil and 17 chemical plants cracking light oil. A smaller version that is close enough is 4 : 1 : 3.
The recipes
| Recipe | Building | In | Out | Time |
|---|---|---|---|---|
| Advanced oil processing | Oil refinery | 100 crude oil, 50 water | 25 heavy oil, 45 light oil, 55 petroleum gas | 5 s |
| Heavy oil cracking | Chemical plant | 40 heavy oil, 30 water | 30 light oil | 2 s |
| Light oil cracking | Chemical plant | 30 light oil, 30 water | 20 petroleum gas | 2 s |
Refineries and chemical plants both have crafting speed 1, so these times are real seconds without modules or beacons.
Where 20 : 5 : 17 comes from
- 20 refineries make 20 × (25, 45, 55) ÷ 5 = 100 heavy oil, 180 light oil and 220 petroleum gas per second, from 400 crude oil per second.
- One heavy cracking plant uses 20 heavy oil per second, so 100 ÷ 20 = 5 plants. They add 5 × 15 = 75 light oil per second.
- That makes 180 + 75 = 255 light oil per second. One light cracking plant uses 15 per second, so 255 ÷ 15 = 17 plants. They add 17 × 10 = 170 petroleum gas per second.
- Total: 220 + 170 = 390 petroleum gas per second from 400 crude oil per second.
Do you really want all petroleum?
Usually not. Lubricant is made from heavy oil and solid fuel or rocket fuel from light oil, so most bases crack only the surplus. The common trick is to let cracking plants run only when their output tank is not full: wire the tank to the pump or inserter feeding the cracking plants with a circuit condition. That way heavy and light oil never back up and stop the refineries.
Smaller builds
| Refineries | Heavy cracking | Light cracking | Petroleum gas per second |
|---|---|---|---|
| 4 | 1 | 3 (3.4 needed) | 74, with a little light oil left over |
| 8 | 2 | 7 (6.8 needed) | 156 |
| 20 | 5 | 17 | 390 |
Space Age
On Vulcanus there is no crude oil: heavy oil comes from coal liquefaction, and the cracking recipes and their ratios stay the same. On Nauvis the recipes are unchanged in Factorio 2.0. Productivity modules in refineries and chemical plants raise the output, so with modules you need slightly more cracking plants per refinery.
Ready-made layouts: power and fuel blueprints and science builds.