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Comment by nautilius | Hacker News Reader

It will not be, because the content of 'artificial' kerosene can be controlled exactly. E.g., there is no way even trace amounts of sulfur could enter manufactured kerosene.

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That means it won't emit sulfur oxides. But those are already heavily controlled and not a big problem. NOx and ozone are created from the chemicals on the atmosphere, and particulate emissions are created by every kind of fire.

There is even a trade-off here in that adjusting the engine for creating less NOx and ozone makes it emit more particulate matter.

I’m still hung up on the NOx. From what I can tell this doesn’t come from atmospheric nitrogen. It’s from nitrogen in the fuel. I’m not sure if this can be controlled or reduced in the synthetic fuel.

It comes from both. How much of it comes from the atmosphere depends on the burning temperature.

Cool fires produce almost none of it from the atmosphere, so all the NOx comes from the fuel. Hot fires produce so much of it from the atmosphere that the fuel is almost irrelevant.

High-efficiency engines, that produce the least CO2, CO, and particulate matter run on very high temperatures, and produce a lot of NOx and ozone.

Thanks for the clarification.

Did you not realize that various NOx compounds are also generated naturally in the atmosphere with no humans involved. And of course when humans start causing high P-T reactions those reactions happen a lot too.

I don’t see how that is relevant in a conversation about marginal human-caused emissions. Natural NOx is the baseline. The question is the specific delta-NOx between conventional and synthetic kerosene.

Yes, but the high-pressure/high-temperature environment of the turbine will spew NOx compounds out too — as I said we’ll have to see the result.

I’m neutral on this plan (scale up will have to be seen) but since you brought up this issue I’m responding.

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