[ya_throw]

It's bogus that jet fuel can be renewable, at least in anywhere near the quantity we currently use. Mainly because the amount of arable land needed is staggering, and we already are destroying virgin rainforest just to feed the world.

[pfdietz]

I mean sure, you can reach that conclusion if your number is off by a factor of 30.

The amount of carbon in paper, cardboard, and food in existing municipal solid waste streams in the US would be nearly enough to make the current US jet fuel demand. It's not like replacing all liquid fuel use -- jet fuel is about 6% of US liquid fuel demand.

[ya_throw]

Do you have a source for that?

Assuming we use the hydrogen conversion process you mentioned, and have fitted the 1000's of square miles of solar panels it would need - I find it hard to believe that the US throws away 90 billion kg of carbon-rich domestic waste every year (apparently, the US gets through about 15 billion gallons of jet fuel per year).

Obviously, even if this is true, we then need to address the other 94% of liquid fossil fuel use.

[pfdietz]

Fuel use: https://www.eia.gov/energyexplained/oil-and-petroleum-produc...

Materials landfilled in MSW:

https://www.epa.gov/facts-and-figures-about-materials-waste-... https://www.statista.com/statistics/1231960/municipal-solid-...

The point is not necessarily to suggest that landfilled material be what is used to make jet fuel, but to point out the volumes are not enormous compared to what's already flowing through the economy. The US produces even more agricultural waste -- over 200 million tonnes of corn stover each year, for example.

The other fuel uses may in many cases be replaced by non-fuels, for example by electrification. Aviation is a special case where the high energy density of chemical fuels, and particularly hydrocarbons, will often be unavoidably attractive.

[ya_throw]

Do you really think that our current lifestyle is at all sustainable, without using nuclear power?

So far, you have suggested that we build several 1000 square miles of solar panels, and dedicate 90 billion kg of carbon-containing material annually, just to fuel 5% of the world population's aviation habit. How do you propose we replace the other 94% of that 5%'s liquid fuel use? After that, how about their total energy use (which dwarfs the total liquid fuel use)?

[pfdietz]

Absolutely. Nuclear power is neither necessary nor particularly useful. Not only is it too expensive, but if used to power the world it requires either breeders (which have not been found to be competitive with our current burner reactors) or very aggressively cheap sea water uranium extraction.

1000 square miles of land sounds like a lot, but for land at $1000/acre (which you can find in much of the US) that's $640M, or maybe 6% of the cost of a single one reactor nuclear power plant.

BTW, the world produces 2,000 million tonnes of municipal solid waste each year. The global production of agricultural waste is also very large. I also wonder how you're going to be fueling those nuclear powered aircraft, if not with carbon-containing synfuels.

[ya_throw]

I don't even care about the cost of the land, it's the mind-boggling amount of solar panels that would need to be manufactured to fill it. Have a think about how the panels would get shipped and fitted in this proposed facility - the panels would start degrading and reaching end of life before you could get anywhere near completion.