ridesthemiles I think you are right. In low travelling periods they can probably have controls and equipment in place to increase what is either more profitable or what is more in demand. I’m not a petroleum engineer, but understand a little of it.
I’m not a petroleum engineer either, but it’s simply a matter of controlling the variables that create the fuel you are looking for. Although, you will still produce some of the other byproducts, which is not completely avoidable.
**Yes, an airline-owned refinery could be engineered (or configured) to produce a significantly higher percentage of jet fuel (kerosene-range product) than a typical commercial refinery.**
Typical U.S. refineries are optimized primarily for **gasoline** (often ~40-50% of output) and **diesel/distillates**, with jet fuel (kerosene-type) usually making up only about 10-11% on average (sometimes cited as ~6-10% globally or in older data). This reflects market demand, where gasoline and road diesel dominate.
### Ways to Increase Jet Fuel Yield
Refineries have flexibility through several levers, and a dedicated airline refinery could push these further (with trade-offs in other products and costs):
- **Crude selection and distillation cuts**: Choose crudes with naturally higher middle-distillate (kerosene) fractions. Adjust distillation tower cut points—e.g., pulling more naphtha into the kerosene range or shifting some diesel-range material—while staying within Jet A/A-1 specs (flash point, freezing point, density, etc.). There are practical limits due to strict jet fuel specifications.
- **Conversion units**:
- **Hydrocracking** is particularly effective for maximizing middle distillates like jet fuel and diesel. It cracks heavier gas oils into jet-range molecules with high yields of high-quality, saturated products (better than fluid catalytic cracking/FCC, which favors gasoline and light olefins).
- Minimize or avoid/reconfigure FCC (common in gasoline-heavy refineries) in favor of hydrocracking or other distillate-oriented processes.
- **Overall configuration**: Build or revamp as a “complex” refinery with hydrocrackers, hydrotreaters, and isomerization tailored for jet. Some refineries have demonstrated shifts toward higher jet/diesel at the expense of gasoline when market conditions (e.g., high jet demand) justify it.
Yields aren’t unlimited. From crude oil, the theoretical maximum for jet fuel is constrained by the hydrocarbon distribution in the feedstock and the need to produce *some* other products (lights, heavies, etc.). Reports suggest jet fuel can reach perhaps 20-30%+ in optimized setups (higher in specific cases or with certain crudes/biocrudes), compared to the typical ~10%. Hydrocracking helps convert heavier fractions but increases light ends and requires hydrogen input/cost.
### Practical Considerations and Trade-offs
- **Economics and specs**: Jet fuel has tight quality requirements (e.g., low aromatics, good cold flow). Over-optimizing can push material out of spec or raise costs (more hydrogen, catalysts, energy). You’d still produce other products to sell or use.
- **Capital and operations**: Designing from scratch or revamping for jet maximization is feasible but expensive. Existing refineries have configuration limits.
- **Supply security benefit**: For an airline, the main value is dedicated, reliable supply (less market volatility) and potentially lower net costs, even if other products are sold on the open market.
- **Real-world precedent**: Refiners already shift yields seasonally or in response to demand (e.g., more jet in summer). Dedicated optimization for one product is done in specialized refineries or biorefineries aiming for high jet output.
In short, **yes**—a purpose-built refinery could deliver a meaningfully higher jet fuel percentage (potentially doubling or more the typical yield share) by prioritizing middle-distillate processes and configuration. The limits are technical specs, crude chemistry, and economics rather than any fundamental impossibility. This is a known strategy discussed in refining literature for meeting aviation demand.